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1009.0892
Chunhua Shen
Yongbin Zheng, Chunhua Shen, Richard Hartley, Xinsheng Huang
Effective Pedestrian Detection Using Center-symmetric Local Binary/Trinary Patterns
11 pages
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Accurately detecting pedestrians in images plays a critically important role in many computer vision applications. Extraction of effective features is the key to this task. Promising features should be discriminative, robust to various variations and easy to compute. In this work, we present novel features, termed dense center-symmetric local binary patterns (CS-LBP) and pyramid center-symmetric local binary/ternary patterns (CS-LBP/LTP), for pedestrian detection. The standard LBP proposed by Ojala et al. \cite{c4} mainly captures the texture information. The proposed CS-LBP feature, in contrast, captures the gradient information and some texture information. Moreover, the proposed dense CS-LBP and the pyramid CS-LBP/LTP are easy to implement and computationally efficient, which is desirable for real-time applications. Experiments on the INRIA pedestrian dataset show that the dense CS-LBP feature with linear supporct vector machines (SVMs) is comparable with the histograms of oriented gradients (HOG) feature with linear SVMs, and the pyramid CS-LBP/LTP features outperform both HOG features with linear SVMs and the start-of-the-art pyramid HOG (PHOG) feature with the histogram intersection kernel SVMs. We also demonstrate that the combination of our pyramid CS-LBP feature and the PHOG feature could significantly improve the detection performance-producing state-of-the-art accuracy on the INRIA pedestrian dataset.
[ { "version": "v1", "created": "Sun, 5 Sep 2010 05:16:11 GMT" }, { "version": "v2", "created": "Fri, 17 Sep 2010 01:58:29 GMT" } ]
2010-09-20T00:00:00
[ [ "Zheng", "Yongbin", "" ], [ "Shen", "Chunhua", "" ], [ "Hartley", "Richard", "" ], [ "Huang", "Xinsheng", "" ] ]
TITLE: Effective Pedestrian Detection Using Center-symmetric Local Binary/Trinary Patterns ABSTRACT: Accurately detecting pedestrians in images plays a critically important role in many computer vision applications. Extraction of effective features is the key to this task. Promising features should be discriminative, robust to various variations and easy to compute. In this work, we present novel features, termed dense center-symmetric local binary patterns (CS-LBP) and pyramid center-symmetric local binary/ternary patterns (CS-LBP/LTP), for pedestrian detection. The standard LBP proposed by Ojala et al. \cite{c4} mainly captures the texture information. The proposed CS-LBP feature, in contrast, captures the gradient information and some texture information. Moreover, the proposed dense CS-LBP and the pyramid CS-LBP/LTP are easy to implement and computationally efficient, which is desirable for real-time applications. Experiments on the INRIA pedestrian dataset show that the dense CS-LBP feature with linear supporct vector machines (SVMs) is comparable with the histograms of oriented gradients (HOG) feature with linear SVMs, and the pyramid CS-LBP/LTP features outperform both HOG features with linear SVMs and the start-of-the-art pyramid HOG (PHOG) feature with the histogram intersection kernel SVMs. We also demonstrate that the combination of our pyramid CS-LBP feature and the PHOG feature could significantly improve the detection performance-producing state-of-the-art accuracy on the INRIA pedestrian dataset.
no_new_dataset
0.95096
1009.2722
Myung Jin Choi
Myung Jin Choi, Vincent Y. F. Tan, Animashree Anandkumar, Alan S. Willsky
Learning Latent Tree Graphical Models
null
null
null
null
stat.ML cs.IT math.IT
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the problem of learning a latent tree graphical model where samples are available only from a subset of variables. We propose two consistent and computationally efficient algorithms for learning minimal latent trees, that is, trees without any redundant hidden nodes. Unlike many existing methods, the observed nodes (or variables) are not constrained to be leaf nodes. Our first algorithm, recursive grouping, builds the latent tree recursively by identifying sibling groups using so-called information distances. One of the main contributions of this work is our second algorithm, which we refer to as CLGrouping. CLGrouping starts with a pre-processing procedure in which a tree over the observed variables is constructed. This global step groups the observed nodes that are likely to be close to each other in the true latent tree, thereby guiding subsequent recursive grouping (or equivalent procedures) on much smaller subsets of variables. This results in more accurate and efficient learning of latent trees. We also present regularized versions of our algorithms that learn latent tree approximations of arbitrary distributions. We compare the proposed algorithms to other methods by performing extensive numerical experiments on various latent tree graphical models such as hidden Markov models and star graphs. In addition, we demonstrate the applicability of our methods on real-world datasets by modeling the dependency structure of monthly stock returns in the S&P index and of the words in the 20 newsgroups dataset.
[ { "version": "v1", "created": "Tue, 14 Sep 2010 17:37:44 GMT" } ]
2010-09-15T00:00:00
[ [ "Choi", "Myung Jin", "" ], [ "Tan", "Vincent Y. F.", "" ], [ "Anandkumar", "Animashree", "" ], [ "Willsky", "Alan S.", "" ] ]
TITLE: Learning Latent Tree Graphical Models ABSTRACT: We study the problem of learning a latent tree graphical model where samples are available only from a subset of variables. We propose two consistent and computationally efficient algorithms for learning minimal latent trees, that is, trees without any redundant hidden nodes. Unlike many existing methods, the observed nodes (or variables) are not constrained to be leaf nodes. Our first algorithm, recursive grouping, builds the latent tree recursively by identifying sibling groups using so-called information distances. One of the main contributions of this work is our second algorithm, which we refer to as CLGrouping. CLGrouping starts with a pre-processing procedure in which a tree over the observed variables is constructed. This global step groups the observed nodes that are likely to be close to each other in the true latent tree, thereby guiding subsequent recursive grouping (or equivalent procedures) on much smaller subsets of variables. This results in more accurate and efficient learning of latent trees. We also present regularized versions of our algorithms that learn latent tree approximations of arbitrary distributions. We compare the proposed algorithms to other methods by performing extensive numerical experiments on various latent tree graphical models such as hidden Markov models and star graphs. In addition, we demonstrate the applicability of our methods on real-world datasets by modeling the dependency structure of monthly stock returns in the S&P index and of the words in the 20 newsgroups dataset.
no_new_dataset
0.948585
1009.0861
Ameet Talwalkar
Mehryar Mohri, Ameet Talwalkar
On the Estimation of Coherence
null
null
null
null
stat.ML cs.AI cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Low-rank matrix approximations are often used to help scale standard machine learning algorithms to large-scale problems. Recently, matrix coherence has been used to characterize the ability to extract global information from a subset of matrix entries in the context of these low-rank approximations and other sampling-based algorithms, e.g., matrix com- pletion, robust PCA. Since coherence is defined in terms of the singular vectors of a matrix and is expensive to compute, the practical significance of these results largely hinges on the following question: Can we efficiently and accurately estimate the coherence of a matrix? In this paper we address this question. We propose a novel algorithm for estimating coherence from a small number of columns, formally analyze its behavior, and derive a new coherence-based matrix approximation bound based on this analysis. We then present extensive experimental results on synthetic and real datasets that corroborate our worst-case theoretical analysis, yet provide strong support for the use of our proposed algorithm whenever low-rank approximation is being considered. Our algorithm efficiently and accurately estimates matrix coherence across a wide range of datasets, and these coherence estimates are excellent predictors of the effectiveness of sampling-based matrix approximation on a case-by-case basis.
[ { "version": "v1", "created": "Sat, 4 Sep 2010 19:18:54 GMT" } ]
2010-09-07T00:00:00
[ [ "Mohri", "Mehryar", "" ], [ "Talwalkar", "Ameet", "" ] ]
TITLE: On the Estimation of Coherence ABSTRACT: Low-rank matrix approximations are often used to help scale standard machine learning algorithms to large-scale problems. Recently, matrix coherence has been used to characterize the ability to extract global information from a subset of matrix entries in the context of these low-rank approximations and other sampling-based algorithms, e.g., matrix com- pletion, robust PCA. Since coherence is defined in terms of the singular vectors of a matrix and is expensive to compute, the practical significance of these results largely hinges on the following question: Can we efficiently and accurately estimate the coherence of a matrix? In this paper we address this question. We propose a novel algorithm for estimating coherence from a small number of columns, formally analyze its behavior, and derive a new coherence-based matrix approximation bound based on this analysis. We then present extensive experimental results on synthetic and real datasets that corroborate our worst-case theoretical analysis, yet provide strong support for the use of our proposed algorithm whenever low-rank approximation is being considered. Our algorithm efficiently and accurately estimates matrix coherence across a wide range of datasets, and these coherence estimates are excellent predictors of the effectiveness of sampling-based matrix approximation on a case-by-case basis.
no_new_dataset
0.945601
1009.0384
Rahmat Widia Sembiring
Rahmat Widia Sembiring, Jasni Mohamad Zain, Abdullah Embong
Clustering high dimensional data using subspace and projected clustering algorithms
9 pages, 6 figures
International journal of computer science & information Technology (IJCSIT) Vol.2, No.4, August 2010, p.162-170
10.5121/ijcsit.2010.2414
null
cs.DB
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Problem statement: Clustering has a number of techniques that have been developed in statistics, pattern recognition, data mining, and other fields. Subspace clustering enumerates clusters of objects in all subspaces of a dataset. It tends to produce many over lapping clusters. Approach: Subspace clustering and projected clustering are research areas for clustering in high dimensional spaces. In this research we experiment three clustering oriented algorithms, PROCLUS, P3C and STATPC. Results: In general, PROCLUS performs better in terms of time of calculation and produced the least number of un-clustered data while STATPC outperforms PROCLUS and P3C in the accuracy of both cluster points and relevant attributes found. Conclusions/Recommendations: In this study, we analyze in detail the properties of different data clustering method.
[ { "version": "v1", "created": "Thu, 2 Sep 2010 10:47:11 GMT" } ]
2010-09-03T00:00:00
[ [ "Sembiring", "Rahmat Widia", "" ], [ "Zain", "Jasni Mohamad", "" ], [ "Embong", "Abdullah", "" ] ]
TITLE: Clustering high dimensional data using subspace and projected clustering algorithms ABSTRACT: Problem statement: Clustering has a number of techniques that have been developed in statistics, pattern recognition, data mining, and other fields. Subspace clustering enumerates clusters of objects in all subspaces of a dataset. It tends to produce many over lapping clusters. Approach: Subspace clustering and projected clustering are research areas for clustering in high dimensional spaces. In this research we experiment three clustering oriented algorithms, PROCLUS, P3C and STATPC. Results: In general, PROCLUS performs better in terms of time of calculation and produced the least number of un-clustered data while STATPC outperforms PROCLUS and P3C in the accuracy of both cluster points and relevant attributes found. Conclusions/Recommendations: In this study, we analyze in detail the properties of different data clustering method.
no_new_dataset
0.953492
1008.4938
Randen Patterson
Yoojin Hong, Kyung Dae Ko, Gaurav Bhardwaj, Zhenhai Zhang, Damian B. van Rossum, and Randen L. Patterson
Towards Solving the Inverse Protein Folding Problem
22 pages, 11 figures
null
null
null
q-bio.QM cs.SC
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Accurately assigning folds for divergent protein sequences is a major obstacle to structural studies and underlies the inverse protein folding problem. Herein, we outline our theories for fold-recognition in the "twilight-zone" of sequence similarity (<25% identity). Our analyses demonstrate that structural sequence profiles built using Position-Specific Scoring Matrices (PSSMs) significantly outperform multiple popular homology-modeling algorithms for relating and predicting structures given only their amino acid sequences. Importantly, structural sequence profiles reconstitute SCOP fold classifications in control and test datasets. Results from our experiments suggest that structural sequence profiles can be used to rapidly annotate protein folds at proteomic scales. We propose that encoding the entire Protein DataBank (~1070 folds) into structural sequence profiles would extract interoperable information capable of improving most if not all methods of structural modeling.
[ { "version": "v1", "created": "Sun, 29 Aug 2010 15:34:02 GMT" } ]
2010-08-31T00:00:00
[ [ "Hong", "Yoojin", "" ], [ "Ko", "Kyung Dae", "" ], [ "Bhardwaj", "Gaurav", "" ], [ "Zhang", "Zhenhai", "" ], [ "van Rossum", "Damian B.", "" ], [ "Patterson", "Randen L.", "" ] ]
TITLE: Towards Solving the Inverse Protein Folding Problem ABSTRACT: Accurately assigning folds for divergent protein sequences is a major obstacle to structural studies and underlies the inverse protein folding problem. Herein, we outline our theories for fold-recognition in the "twilight-zone" of sequence similarity (<25% identity). Our analyses demonstrate that structural sequence profiles built using Position-Specific Scoring Matrices (PSSMs) significantly outperform multiple popular homology-modeling algorithms for relating and predicting structures given only their amino acid sequences. Importantly, structural sequence profiles reconstitute SCOP fold classifications in control and test datasets. Results from our experiments suggest that structural sequence profiles can be used to rapidly annotate protein folds at proteomic scales. We propose that encoding the entire Protein DataBank (~1070 folds) into structural sequence profiles would extract interoperable information capable of improving most if not all methods of structural modeling.
no_new_dataset
0.946151
1008.3629
Dhouha Grissa
Dhouha Grissa, Sylvie Guillaume and Engelbert Mephu Nguifo
Combining Clustering techniques and Formal Concept Analysis to characterize Interestingness Measures
13 pages, 2 figures
null
null
null
cs.IT math.IT
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Formal Concept Analysis "FCA" is a data analysis method which enables to discover hidden knowledge existing in data. A kind of hidden knowledge extracted from data is association rules. Different quality measures were reported in the literature to extract only relevant association rules. Given a dataset, the choice of a good quality measure remains a challenging task for a user. Given a quality measures evaluation matrix according to semantic properties, this paper describes how FCA can highlight quality measures with similar behavior in order to help the user during his choice. The aim of this article is the discovery of Interestingness Measures "IM" clusters, able to validate those found due to the hierarchical and partitioning clustering methods "AHC" and "k-means". Then, based on the theoretical study of sixty one interestingness measures according to nineteen properties, proposed in a recent study, "FCA" describes several groups of measures.
[ { "version": "v1", "created": "Sat, 21 Aug 2010 13:23:23 GMT" } ]
2010-08-24T00:00:00
[ [ "Grissa", "Dhouha", "" ], [ "Guillaume", "Sylvie", "" ], [ "Nguifo", "Engelbert Mephu", "" ] ]
TITLE: Combining Clustering techniques and Formal Concept Analysis to characterize Interestingness Measures ABSTRACT: Formal Concept Analysis "FCA" is a data analysis method which enables to discover hidden knowledge existing in data. A kind of hidden knowledge extracted from data is association rules. Different quality measures were reported in the literature to extract only relevant association rules. Given a dataset, the choice of a good quality measure remains a challenging task for a user. Given a quality measures evaluation matrix according to semantic properties, this paper describes how FCA can highlight quality measures with similar behavior in order to help the user during his choice. The aim of this article is the discovery of Interestingness Measures "IM" clusters, able to validate those found due to the hierarchical and partitioning clustering methods "AHC" and "k-means". Then, based on the theoretical study of sixty one interestingness measures according to nineteen properties, proposed in a recent study, "FCA" describes several groups of measures.
no_new_dataset
0.947381
1007.0437
Adrian Melott
Adrian L. Melott (University of Kansas) and Richard K. Bambach (Smithsonian Institution Museum of Natural History)
Nemesis Reconsidered
10 pages, 2 figures, accepted for publication in Monthly Notices of the Royal Astronomical Society
Monthly Notices of the Royal Astronomical Society Letters 407, L99-L102 (2010)
10.1111/j.1745-3933.2010.00913.x
null
astro-ph.SR astro-ph.EP astro-ph.GA physics.geo-ph q-bio.PE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The hypothesis of a companion object (Nemesis) orbiting the Sun was motivated by the claim of a terrestrial extinction periodicity, thought to be mediated by comet showers. The orbit of a distant companion to the Sun is expected to be perturbed by the Galactic tidal field and encounters with passing stars, which will induce variation in the period. We examine the evidence for the previously proposed periodicity, using two modern, greatly improved paleontological datasets of fossil biodiversity. We find that there is a narrow peak at 27 My in the cross-spectrum of extinction intensity time series between these independent datasets. This periodicity extends over a time period nearly twice that for which it was originally noted. An excess of extinction events are associated with this periodicity at 99% confidence. In this sense we confirm the originally noted feature in the time series for extinction. However, we find that it displays extremely regular timing for about 0.5 Gy. The regularity of the timing compared with earlier calculations of orbital perturbation would seem to exclude the Nemesis hypothesis as a causal factor.
[ { "version": "v1", "created": "Fri, 2 Jul 2010 19:59:47 GMT" } ]
2010-08-20T00:00:00
[ [ "Melott", "Adrian L.", "", "University of Kansas" ], [ "Bambach", "Richard K.", "", "Smithsonian Institution Museum of Natural History" ] ]
TITLE: Nemesis Reconsidered ABSTRACT: The hypothesis of a companion object (Nemesis) orbiting the Sun was motivated by the claim of a terrestrial extinction periodicity, thought to be mediated by comet showers. The orbit of a distant companion to the Sun is expected to be perturbed by the Galactic tidal field and encounters with passing stars, which will induce variation in the period. We examine the evidence for the previously proposed periodicity, using two modern, greatly improved paleontological datasets of fossil biodiversity. We find that there is a narrow peak at 27 My in the cross-spectrum of extinction intensity time series between these independent datasets. This periodicity extends over a time period nearly twice that for which it was originally noted. An excess of extinction events are associated with this periodicity at 99% confidence. In this sense we confirm the originally noted feature in the time series for extinction. However, we find that it displays extremely regular timing for about 0.5 Gy. The regularity of the timing compared with earlier calculations of orbital perturbation would seem to exclude the Nemesis hypothesis as a causal factor.
no_new_dataset
0.942718
1008.2877
Dr. Wolfgang A. Rolke
Wolfgang Rolke and Angel Lopez
A Test for Equality of Distributions in High Dimensions
12 pages, 4 figures
null
null
null
physics.data-an astro-ph.IM hep-ex stat.ME
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a method which tests whether or not two datasets (one of which could be Monte Carlo generated) might come from the same distribution. Our method works in arbitrarily high dimensions.
[ { "version": "v1", "created": "Tue, 17 Aug 2010 12:27:16 GMT" } ]
2010-08-18T00:00:00
[ [ "Rolke", "Wolfgang", "" ], [ "Lopez", "Angel", "" ] ]
TITLE: A Test for Equality of Distributions in High Dimensions ABSTRACT: We present a method which tests whether or not two datasets (one of which could be Monte Carlo generated) might come from the same distribution. Our method works in arbitrarily high dimensions.
no_new_dataset
0.955319
1008.2574
Jinyoung Han
Jinyoung Han, Taejoong Chung, Seungbae Kim, Hyun-chul Kim, Ted "Taekyoung" Kwon, Yanghee Choi
An Empirical Study on Content Bundling in BitTorrent Swarming System
null
null
null
null
cs.NI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Despite the tremendous success of BitTorrent, its swarming system suffers from a fundamental limitation: lower or no availability of unpopular contents. Recently, Menasche et al. has shown that bundling is a promising solution to mitigate this availability problem; it improves the availability and reduces download times for unpopular contents by combining multiple files into a single swarm. There also have been studies on bundling strategies and performance issues in bundled swarms. In spite of the recent surge of interest in the benefits of and strategies for bundling, there are still little empirical grounding for understanding, describing, and modeling it. This is the first empirical study that measures and analyzes how prevalent contents bundling is in BitTorrent and how peers access the bundled contents, in comparison to the other non-bundled (i.e., single-filed) ones. To our surprise, we found that around 70% of BitTorrent swarms contain multiple files, which indicate that bundling has become widespread for contents sharing. We also show that the amount of bytes shared in bundled swarms is estimated to be around 85% out of all the BitTorrent contents logged in our datasets. Inspired from our findings, we raise and discuss three important research questions in the field of file sharing systems as well as future contents-oriented networking: i) bundling strategies, ii) bundling-aware sharing systems in BitTorrent, and iii) implications on content-oriented networking.
[ { "version": "v1", "created": "Mon, 16 Aug 2010 05:25:19 GMT" } ]
2010-08-17T00:00:00
[ [ "Han", "Jinyoung", "" ], [ "Chung", "Taejoong", "" ], [ "Kim", "Seungbae", "" ], [ "Kim", "Hyun-chul", "" ], [ "Kwon", "Ted \"Taekyoung\"", "" ], [ "Choi", "Yanghee", "" ] ]
TITLE: An Empirical Study on Content Bundling in BitTorrent Swarming System ABSTRACT: Despite the tremendous success of BitTorrent, its swarming system suffers from a fundamental limitation: lower or no availability of unpopular contents. Recently, Menasche et al. has shown that bundling is a promising solution to mitigate this availability problem; it improves the availability and reduces download times for unpopular contents by combining multiple files into a single swarm. There also have been studies on bundling strategies and performance issues in bundled swarms. In spite of the recent surge of interest in the benefits of and strategies for bundling, there are still little empirical grounding for understanding, describing, and modeling it. This is the first empirical study that measures and analyzes how prevalent contents bundling is in BitTorrent and how peers access the bundled contents, in comparison to the other non-bundled (i.e., single-filed) ones. To our surprise, we found that around 70% of BitTorrent swarms contain multiple files, which indicate that bundling has become widespread for contents sharing. We also show that the amount of bytes shared in bundled swarms is estimated to be around 85% out of all the BitTorrent contents logged in our datasets. Inspired from our findings, we raise and discuss three important research questions in the field of file sharing systems as well as future contents-oriented networking: i) bundling strategies, ii) bundling-aware sharing systems in BitTorrent, and iii) implications on content-oriented networking.
no_new_dataset
0.930395
1008.2626
Jan Van den Bussche
Eveline Hoekx and Jan Van den Bussche
Mining tree-query associations in graphs
Full version of two earlier conference papers presented at KDD 2005 and ICDM 2006
null
null
null
cs.DB cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
New applications of data mining, such as in biology, bioinformatics, or sociology, are faced with large datasetsstructured as graphs. We introduce a novel class of tree-shapedpatterns called tree queries, and present algorithms for miningtree queries and tree-query associations in a large data graph. Novel about our class of patterns is that they can containconstants, and can contain existential nodes which are not counted when determining the number of occurrences of the patternin the data graph. Our algorithms have a number of provableoptimality properties, which are based on the theory of conjunctive database queries. We propose a practical, database-oriented implementation in SQL, and show that the approach works in practice through experiments on data about food webs, protein interactions, and citation analysis.
[ { "version": "v1", "created": "Mon, 16 Aug 2010 11:35:59 GMT" } ]
2010-08-17T00:00:00
[ [ "Hoekx", "Eveline", "" ], [ "Bussche", "Jan Van den", "" ] ]
TITLE: Mining tree-query associations in graphs ABSTRACT: New applications of data mining, such as in biology, bioinformatics, or sociology, are faced with large datasetsstructured as graphs. We introduce a novel class of tree-shapedpatterns called tree queries, and present algorithms for miningtree queries and tree-query associations in a large data graph. Novel about our class of patterns is that they can containconstants, and can contain existential nodes which are not counted when determining the number of occurrences of the patternin the data graph. Our algorithms have a number of provableoptimality properties, which are based on the theory of conjunctive database queries. We propose a practical, database-oriented implementation in SQL, and show that the approach works in practice through experiments on data about food webs, protein interactions, and citation analysis.
no_new_dataset
0.945551
1008.1253
Wojciech Galuba
Daniel M. Romero, Wojciech Galuba, Sitaram Asur and Bernardo A. Huberman
Influence and Passivity in Social Media
null
null
null
null
cs.CY physics.soc-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The ever-increasing amount of information flowing through Social Media forces the members of these networks to compete for attention and influence by relying on other people to spread their message. A large study of information propagation within Twitter reveals that the majority of users act as passive information consumers and do not forward the content to the network. Therefore, in order for individuals to become influential they must not only obtain attention and thus be popular, but also overcome user passivity. We propose an algorithm that determines the influence and passivity of users based on their information forwarding activity. An evaluation performed with a 2.5 million user dataset shows that our influence measure is a good predictor of URL clicks, outperforming several other measures that do not explicitly take user passivity into account. We also explicitly demonstrate that high popularity does not necessarily imply high influence and vice-versa.
[ { "version": "v1", "created": "Fri, 6 Aug 2010 18:54:10 GMT" } ]
2010-08-09T00:00:00
[ [ "Romero", "Daniel M.", "" ], [ "Galuba", "Wojciech", "" ], [ "Asur", "Sitaram", "" ], [ "Huberman", "Bernardo A.", "" ] ]
TITLE: Influence and Passivity in Social Media ABSTRACT: The ever-increasing amount of information flowing through Social Media forces the members of these networks to compete for attention and influence by relying on other people to spread their message. A large study of information propagation within Twitter reveals that the majority of users act as passive information consumers and do not forward the content to the network. Therefore, in order for individuals to become influential they must not only obtain attention and thus be popular, but also overcome user passivity. We propose an algorithm that determines the influence and passivity of users based on their information forwarding activity. An evaluation performed with a 2.5 million user dataset shows that our influence measure is a good predictor of URL clicks, outperforming several other measures that do not explicitly take user passivity into account. We also explicitly demonstrate that high popularity does not necessarily imply high influence and vice-versa.
no_new_dataset
0.940463
1007.3564
Dacheng Tao
Tianyi Zhou, Dacheng Tao, Xindong Wu
Manifold Elastic Net: A Unified Framework for Sparse Dimension Reduction
33 pages, 12 figures
Journal of Data Mining and Knowledge Discovery, 2010
10.1007/s10618-010-0182-x
null
cs.LG stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is difficult to find the optimal sparse solution of a manifold learning based dimensionality reduction algorithm. The lasso or the elastic net penalized manifold learning based dimensionality reduction is not directly a lasso penalized least square problem and thus the least angle regression (LARS) (Efron et al. \cite{LARS}), one of the most popular algorithms in sparse learning, cannot be applied. Therefore, most current approaches take indirect ways or have strict settings, which can be inconvenient for applications. In this paper, we proposed the manifold elastic net or MEN for short. MEN incorporates the merits of both the manifold learning based dimensionality reduction and the sparse learning based dimensionality reduction. By using a series of equivalent transformations, we show MEN is equivalent to the lasso penalized least square problem and thus LARS is adopted to obtain the optimal sparse solution of MEN. In particular, MEN has the following advantages for subsequent classification: 1) the local geometry of samples is well preserved for low dimensional data representation, 2) both the margin maximization and the classification error minimization are considered for sparse projection calculation, 3) the projection matrix of MEN improves the parsimony in computation, 4) the elastic net penalty reduces the over-fitting problem, and 5) the projection matrix of MEN can be interpreted psychologically and physiologically. Experimental evidence on face recognition over various popular datasets suggests that MEN is superior to top level dimensionality reduction algorithms.
[ { "version": "v1", "created": "Wed, 21 Jul 2010 05:50:47 GMT" }, { "version": "v2", "created": "Sat, 24 Jul 2010 03:48:30 GMT" }, { "version": "v3", "created": "Tue, 27 Jul 2010 03:01:09 GMT" } ]
2010-07-28T00:00:00
[ [ "Zhou", "Tianyi", "" ], [ "Tao", "Dacheng", "" ], [ "Wu", "Xindong", "" ] ]
TITLE: Manifold Elastic Net: A Unified Framework for Sparse Dimension Reduction ABSTRACT: It is difficult to find the optimal sparse solution of a manifold learning based dimensionality reduction algorithm. The lasso or the elastic net penalized manifold learning based dimensionality reduction is not directly a lasso penalized least square problem and thus the least angle regression (LARS) (Efron et al. \cite{LARS}), one of the most popular algorithms in sparse learning, cannot be applied. Therefore, most current approaches take indirect ways or have strict settings, which can be inconvenient for applications. In this paper, we proposed the manifold elastic net or MEN for short. MEN incorporates the merits of both the manifold learning based dimensionality reduction and the sparse learning based dimensionality reduction. By using a series of equivalent transformations, we show MEN is equivalent to the lasso penalized least square problem and thus LARS is adopted to obtain the optimal sparse solution of MEN. In particular, MEN has the following advantages for subsequent classification: 1) the local geometry of samples is well preserved for low dimensional data representation, 2) both the margin maximization and the classification error minimization are considered for sparse projection calculation, 3) the projection matrix of MEN improves the parsimony in computation, 4) the elastic net penalty reduces the over-fitting problem, and 5) the projection matrix of MEN can be interpreted psychologically and physiologically. Experimental evidence on face recognition over various popular datasets suggests that MEN is superior to top level dimensionality reduction algorithms.
no_new_dataset
0.954351
1001.1122
Alexander Gorban
A. N. Gorban, A. Zinovyev
Principal manifolds and graphs in practice: from molecular biology to dynamical systems
12 pages, 9 figures
International Journal of Neural Systems, Vol. 20, No. 3 (2010) 219-232
10.1142/S0129065710002383
null
cs.NE cs.AI
http://creativecommons.org/licenses/by/3.0/
We present several applications of non-linear data modeling, using principal manifolds and principal graphs constructed using the metaphor of elasticity (elastic principal graph approach). These approaches are generalizations of the Kohonen's self-organizing maps, a class of artificial neural networks. On several examples we show advantages of using non-linear objects for data approximation in comparison to the linear ones. We propose four numerical criteria for comparing linear and non-linear mappings of datasets into the spaces of lower dimension. The examples are taken from comparative political science, from analysis of high-throughput data in molecular biology, from analysis of dynamical systems.
[ { "version": "v1", "created": "Thu, 7 Jan 2010 17:46:17 GMT" }, { "version": "v2", "created": "Sun, 25 Jul 2010 19:30:37 GMT" } ]
2010-07-27T00:00:00
[ [ "Gorban", "A. N.", "" ], [ "Zinovyev", "A.", "" ] ]
TITLE: Principal manifolds and graphs in practice: from molecular biology to dynamical systems ABSTRACT: We present several applications of non-linear data modeling, using principal manifolds and principal graphs constructed using the metaphor of elasticity (elastic principal graph approach). These approaches are generalizations of the Kohonen's self-organizing maps, a class of artificial neural networks. On several examples we show advantages of using non-linear objects for data approximation in comparison to the linear ones. We propose four numerical criteria for comparing linear and non-linear mappings of datasets into the spaces of lower dimension. The examples are taken from comparative political science, from analysis of high-throughput data in molecular biology, from analysis of dynamical systems.
no_new_dataset
0.949809
1007.0824
Remi Flamary
R\'emi Flamary (LITIS), Benjamin Labb\'e (LITIS), Alain Rakotomamonjy (LITIS)
Filtrage vaste marge pour l'\'etiquetage s\'equentiel \`a noyaux de signaux
null
Conf\'erence Francophone sur l'Apprentissage Automatique, Clermont Ferrand : France (2010)
null
null
cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We address in this paper the problem of multi-channel signal sequence labeling. In particular, we consider the problem where the signals are contaminated by noise or may present some dephasing with respect to their labels. For that, we propose to jointly learn a SVM sample classifier with a temporal filtering of the channels. This will lead to a large margin filtering that is adapted to the specificity of each channel (noise and time-lag). We derive algorithms to solve the optimization problem and we discuss different filter regularizations for automated scaling or selection of channels. Our approach is tested on a non-linear toy example and on a BCI dataset. Results show that the classification performance on these problems can be improved by learning a large margin filtering.
[ { "version": "v1", "created": "Tue, 6 Jul 2010 07:47:00 GMT" } ]
2010-07-26T00:00:00
[ [ "Flamary", "Rémi", "", "LITIS" ], [ "Labbé", "Benjamin", "", "LITIS" ], [ "Rakotomamonjy", "Alain", "", "LITIS" ] ]
TITLE: Filtrage vaste marge pour l'\'etiquetage s\'equentiel \`a noyaux de signaux ABSTRACT: We address in this paper the problem of multi-channel signal sequence labeling. In particular, we consider the problem where the signals are contaminated by noise or may present some dephasing with respect to their labels. For that, we propose to jointly learn a SVM sample classifier with a temporal filtering of the channels. This will lead to a large margin filtering that is adapted to the specificity of each channel (noise and time-lag). We derive algorithms to solve the optimization problem and we discuss different filter regularizations for automated scaling or selection of channels. Our approach is tested on a non-linear toy example and on a BCI dataset. Results show that the classification performance on these problems can be improved by learning a large margin filtering.
no_new_dataset
0.950041
1003.0470
Krishnakumar Balasubramanian
Krishnakumar Balasubramanian, Pinar Donmez, Guy Lebanon
Unsupervised Supervised Learning II: Training Margin Based Classifiers without Labels
22 pages, 43 figures
null
null
null
cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Many popular linear classifiers, such as logistic regression, boosting, or SVM, are trained by optimizing a margin-based risk function. Traditionally, these risk functions are computed based on a labeled dataset. We develop a novel technique for estimating such risks using only unlabeled data and the marginal label distribution. We prove that the proposed risk estimator is consistent on high-dimensional datasets and demonstrate it on synthetic and real-world data. In particular, we show how the estimate is used for evaluating classifiers in transfer learning, and for training classifiers with no labeled data whatsoever.
[ { "version": "v1", "created": "Mon, 1 Mar 2010 22:32:18 GMT" }, { "version": "v2", "created": "Wed, 21 Jul 2010 21:19:35 GMT" } ]
2010-07-23T00:00:00
[ [ "Balasubramanian", "Krishnakumar", "" ], [ "Donmez", "Pinar", "" ], [ "Lebanon", "Guy", "" ] ]
TITLE: Unsupervised Supervised Learning II: Training Margin Based Classifiers without Labels ABSTRACT: Many popular linear classifiers, such as logistic regression, boosting, or SVM, are trained by optimizing a margin-based risk function. Traditionally, these risk functions are computed based on a labeled dataset. We develop a novel technique for estimating such risks using only unlabeled data and the marginal label distribution. We prove that the proposed risk estimator is consistent on high-dimensional datasets and demonstrate it on synthetic and real-world data. In particular, we show how the estimate is used for evaluating classifiers in transfer learning, and for training classifiers with no labeled data whatsoever.
no_new_dataset
0.949995
1007.3553
Francois Meyer
Kye M. Taylor, Michael J. Procopio, Christopher J. Young, and Francois G. Meyer
Exploring the Manifold of Seismic Waves: Application to the Estimation of Arrival-Times
21 pages, 13 figures
null
null
null
physics.data-an nlin.CD physics.geo-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a new method to analyze seismic time series and estimate the arrival-times of seismic waves. Our approach combines two ingredients: the times series are first lifted into a high-dimensional space using time-delay embedding; the resulting phase space is then parametrized using a nonlinear method based on the eigenvectors of the graph Laplacian. We validate our approach using a dataset of seismic events that occurred in Idaho, Montana, Wyoming, and Utah, between 2005 and 2006. Our approach outperforms methods based on singular-spectrum analysis, waveleta nalysis, and STA/LTA.
[ { "version": "v1", "created": "Wed, 21 Jul 2010 02:46:30 GMT" }, { "version": "v2", "created": "Thu, 22 Jul 2010 00:39:21 GMT" } ]
2010-07-23T00:00:00
[ [ "Taylor", "Kye M.", "" ], [ "Procopio", "Michael J.", "" ], [ "Young", "Christopher J.", "" ], [ "Meyer", "Francois G.", "" ] ]
TITLE: Exploring the Manifold of Seismic Waves: Application to the Estimation of Arrival-Times ABSTRACT: We propose a new method to analyze seismic time series and estimate the arrival-times of seismic waves. Our approach combines two ingredients: the times series are first lifted into a high-dimensional space using time-delay embedding; the resulting phase space is then parametrized using a nonlinear method based on the eigenvectors of the graph Laplacian. We validate our approach using a dataset of seismic events that occurred in Idaho, Montana, Wyoming, and Utah, between 2005 and 2006. Our approach outperforms methods based on singular-spectrum analysis, waveleta nalysis, and STA/LTA.
new_dataset
0.9462
1007.3680
Alain Barrat
Ciro Cattuto, Wouter Van den Broeck, Alain Barrat, Vittoria Colizza, Jean-Fran\c{c}ois Pinton, Alessandro Vespignani
Dynamics of person-to-person interactions from distributed RFID sensor networks
see also http://www.sociopatterns.org
PLoS ONE 5(7): e11596 (2010)
10.1371/journal.pone.0011596
null
physics.soc-ph cond-mat.stat-mech cs.HC q-bio.OT
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Digital networks, mobile devices, and the possibility of mining the ever-increasing amount of digital traces that we leave behind in our daily activities are changing the way we can approach the study of human and social interactions. Large-scale datasets, however, are mostly available for collective and statistical behaviors, at coarse granularities, while high-resolution data on person-to-person interactions are generally limited to relatively small groups of individuals. Here we present a scalable experimental framework for gathering real-time data resolving face-to-face social interactions with tunable spatial and temporal granularities. We use active Radio Frequency Identification (RFID) devices that assess mutual proximity in a distributed fashion by exchanging low-power radio packets. We analyze the dynamics of person-to-person interaction networks obtained in three high-resolution experiments carried out at different orders of magnitude in community size. The data sets exhibit common statistical properties and lack of a characteristic time scale from 20 seconds to several hours. The association between the number of connections and their duration shows an interesting super-linear behavior, which indicates the possibility of defining super-connectors both in the number and intensity of connections. Taking advantage of scalability and resolution, this experimental framework allows the monitoring of social interactions, uncovering similarities in the way individuals interact in different contexts, and identifying patterns of super-connector behavior in the community. These results could impact our understanding of all phenomena driven by face-to-face interactions, such as the spreading of transmissible infectious diseases and information.
[ { "version": "v1", "created": "Wed, 21 Jul 2010 15:35:18 GMT" } ]
2010-07-22T00:00:00
[ [ "Cattuto", "Ciro", "" ], [ "Broeck", "Wouter Van den", "" ], [ "Barrat", "Alain", "" ], [ "Colizza", "Vittoria", "" ], [ "Pinton", "Jean-François", "" ], [ "Vespignani", "Alessandro", "" ] ]
TITLE: Dynamics of person-to-person interactions from distributed RFID sensor networks ABSTRACT: Digital networks, mobile devices, and the possibility of mining the ever-increasing amount of digital traces that we leave behind in our daily activities are changing the way we can approach the study of human and social interactions. Large-scale datasets, however, are mostly available for collective and statistical behaviors, at coarse granularities, while high-resolution data on person-to-person interactions are generally limited to relatively small groups of individuals. Here we present a scalable experimental framework for gathering real-time data resolving face-to-face social interactions with tunable spatial and temporal granularities. We use active Radio Frequency Identification (RFID) devices that assess mutual proximity in a distributed fashion by exchanging low-power radio packets. We analyze the dynamics of person-to-person interaction networks obtained in three high-resolution experiments carried out at different orders of magnitude in community size. The data sets exhibit common statistical properties and lack of a characteristic time scale from 20 seconds to several hours. The association between the number of connections and their duration shows an interesting super-linear behavior, which indicates the possibility of defining super-connectors both in the number and intensity of connections. Taking advantage of scalability and resolution, this experimental framework allows the monitoring of social interactions, uncovering similarities in the way individuals interact in different contexts, and identifying patterns of super-connector behavior in the community. These results could impact our understanding of all phenomena driven by face-to-face interactions, such as the spreading of transmissible infectious diseases and information.
no_new_dataset
0.943243
1007.2958
Hoang Trinh
Hoang Trinh
A Machine Learning Approach to Recovery of Scene Geometry from Images
null
null
null
null
cs.CV cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recovering the 3D structure of the scene from images yields useful information for tasks such as shape and scene recognition, object detection, or motion planning and object grasping in robotics. In this thesis, we introduce a general machine learning approach called unsupervised CRF learning based on maximizing the conditional likelihood. We apply our approach to computer vision systems that recover the 3-D scene geometry from images. We focus on recovering 3D geometry from single images, stereo pairs and video sequences. Building these systems requires algorithms for doing inference as well as learning the parameters of conditional Markov random fields (MRF). Our system is trained unsupervisedly without using ground-truth labeled data. We employ a slanted-plane stereo vision model in which we use a fixed over-segmentation to segment the left image into coherent regions called superpixels, then assign a disparity plane for each superpixel. Plane parameters are estimated by solving an MRF labelling problem, through minimizing an energy fuction. We demonstrate the use of our unsupervised CRF learning algorithm for a parameterized slanted-plane stereo vision model involving shape from texture cues. Our stereo model with texture cues, only by unsupervised training, outperforms the results in related work on the same stereo dataset. In this thesis, we also formulate structure and motion estimation as an energy minimization problem, in which the model is an extension of our slanted-plane stereo vision model that also handles surface velocity. Velocity estimation is achieved by solving an MRF labeling problem using Loopy BP. Performance analysis is done using our novel evaluation metrics based on the notion of view prediction error. Experiments on road-driving stereo sequences show encouraging results.
[ { "version": "v1", "created": "Sat, 17 Jul 2010 19:59:11 GMT" } ]
2010-07-20T00:00:00
[ [ "Trinh", "Hoang", "" ] ]
TITLE: A Machine Learning Approach to Recovery of Scene Geometry from Images ABSTRACT: Recovering the 3D structure of the scene from images yields useful information for tasks such as shape and scene recognition, object detection, or motion planning and object grasping in robotics. In this thesis, we introduce a general machine learning approach called unsupervised CRF learning based on maximizing the conditional likelihood. We apply our approach to computer vision systems that recover the 3-D scene geometry from images. We focus on recovering 3D geometry from single images, stereo pairs and video sequences. Building these systems requires algorithms for doing inference as well as learning the parameters of conditional Markov random fields (MRF). Our system is trained unsupervisedly without using ground-truth labeled data. We employ a slanted-plane stereo vision model in which we use a fixed over-segmentation to segment the left image into coherent regions called superpixels, then assign a disparity plane for each superpixel. Plane parameters are estimated by solving an MRF labelling problem, through minimizing an energy fuction. We demonstrate the use of our unsupervised CRF learning algorithm for a parameterized slanted-plane stereo vision model involving shape from texture cues. Our stereo model with texture cues, only by unsupervised training, outperforms the results in related work on the same stereo dataset. In this thesis, we also formulate structure and motion estimation as an energy minimization problem, in which the model is an extension of our slanted-plane stereo vision model that also handles surface velocity. Velocity estimation is achieved by solving an MRF labeling problem using Loopy BP. Performance analysis is done using our novel evaluation metrics based on the notion of view prediction error. Experiments on road-driving stereo sequences show encouraging results.
no_new_dataset
0.954563
1007.2545
Anirban Chakraborti
Kimmo Kaski
Social Complexity: can it be analyzed and modelled?
5 pages, 2 figures, REVTeX. To appear in "Econophysics", a special issue in Science and Culture (Kolkata, India) to celebrate 15 years of Econophysics
null
null
null
physics.soc-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Over the past decade network theory has turned out to be a powerful methodology to investigate complex systems of various sorts. Through data analysis, modeling, and simulation quite an unparalleled insight into their structure, function, and response can be obtained. In human societies individuals are linked through social interactions, which today are increasingly mediated electronically by modern Information Communication Technology thus leaving "footprints" of human behaviour as digital records. For these datasets the network theory approach is a natural one as we have demonstrated by analysing the dataset of multi-million user mobile phone communication-logs. This social network turned out to be modular in structure showing communities where individuals are connected with stronger ties and between communities with weaker ties. Also the network topology and the weighted links for pairs of individuals turned out to be related.These empirical findings inspired us to take the next step in network theory, by developing a simple network model based on basic network sociology mechanisms to get friends in order to catch some salient features of mesoscopic community and macroscopic topology formation. Our model turned out to produce many empirically observed features of large-scale social networks. Thus we believe that the network theory approach combining data analysis with modeling and simulation could open a new perspective for studying and even predicting various collective social phenomena such as information spreading, formation of societal structures, and evolutionary processes in them.
[ { "version": "v1", "created": "Thu, 15 Jul 2010 12:43:35 GMT" } ]
2010-07-16T00:00:00
[ [ "Kaski", "Kimmo", "" ] ]
TITLE: Social Complexity: can it be analyzed and modelled? ABSTRACT: Over the past decade network theory has turned out to be a powerful methodology to investigate complex systems of various sorts. Through data analysis, modeling, and simulation quite an unparalleled insight into their structure, function, and response can be obtained. In human societies individuals are linked through social interactions, which today are increasingly mediated electronically by modern Information Communication Technology thus leaving "footprints" of human behaviour as digital records. For these datasets the network theory approach is a natural one as we have demonstrated by analysing the dataset of multi-million user mobile phone communication-logs. This social network turned out to be modular in structure showing communities where individuals are connected with stronger ties and between communities with weaker ties. Also the network topology and the weighted links for pairs of individuals turned out to be related.These empirical findings inspired us to take the next step in network theory, by developing a simple network model based on basic network sociology mechanisms to get friends in order to catch some salient features of mesoscopic community and macroscopic topology formation. Our model turned out to produce many empirically observed features of large-scale social networks. Thus we believe that the network theory approach combining data analysis with modeling and simulation could open a new perspective for studying and even predicting various collective social phenomena such as information spreading, formation of societal structures, and evolutionary processes in them.
no_new_dataset
0.945751
1005.4496
Secretary Aircc Journal
Dewan Md. Farid(1), Nouria Harbi(1), and Mohammad Zahidur Rahman(2), ((1)University Lumiere Lyon 2 - France, (2)Jahangirnagar University, Bangladesh)
Combining Naive Bayes and Decision Tree for Adaptive Intrusion Detection
14 Pages, IJNSA
International Journal of Network Security & Its Applications 2.2 (2010) 12-25
10.5121/ijnsa.2010.2202
null
cs.AI
http://creativecommons.org/licenses/by-nc-sa/3.0/
In this paper, a new learning algorithm for adaptive network intrusion detection using naive Bayesian classifier and decision tree is presented, which performs balance detections and keeps false positives at acceptable level for different types of network attacks, and eliminates redundant attributes as well as contradictory examples from training data that make the detection model complex. The proposed algorithm also addresses some difficulties of data mining such as handling continuous attribute, dealing with missing attribute values, and reducing noise in training data. Due to the large volumes of security audit data as well as the complex and dynamic properties of intrusion behaviours, several data miningbased intrusion detection techniques have been applied to network-based traffic data and host-based data in the last decades. However, there remain various issues needed to be examined towards current intrusion detection systems (IDS). We tested the performance of our proposed algorithm with existing learning algorithms by employing on the KDD99 benchmark intrusion detection dataset. The experimental results prove that the proposed algorithm achieved high detection rates (DR) and significant reduce false positives (FP) for different types of network intrusions using limited computational resources.
[ { "version": "v1", "created": "Tue, 25 May 2010 07:47:00 GMT" } ]
2010-07-15T00:00:00
[ [ "Farid", "Dewan Md.", "" ], [ "Harbi", "Nouria", "" ], [ "Rahman", "Mohammad Zahidur", "" ] ]
TITLE: Combining Naive Bayes and Decision Tree for Adaptive Intrusion Detection ABSTRACT: In this paper, a new learning algorithm for adaptive network intrusion detection using naive Bayesian classifier and decision tree is presented, which performs balance detections and keeps false positives at acceptable level for different types of network attacks, and eliminates redundant attributes as well as contradictory examples from training data that make the detection model complex. The proposed algorithm also addresses some difficulties of data mining such as handling continuous attribute, dealing with missing attribute values, and reducing noise in training data. Due to the large volumes of security audit data as well as the complex and dynamic properties of intrusion behaviours, several data miningbased intrusion detection techniques have been applied to network-based traffic data and host-based data in the last decades. However, there remain various issues needed to be examined towards current intrusion detection systems (IDS). We tested the performance of our proposed algorithm with existing learning algorithms by employing on the KDD99 benchmark intrusion detection dataset. The experimental results prove that the proposed algorithm achieved high detection rates (DR) and significant reduce false positives (FP) for different types of network intrusions using limited computational resources.
no_new_dataset
0.947186
1005.5434
Secretary Aircc Journal
B.N. Keshavamurthy, Mitesh Sharma and Durga Toshniwal
Efficient Support Coupled Frequent Pattern Mining Over Progressive Databases
10 Pages, IJDMS
International Journal of Database Management Systems 2.2 (2010) 73-82
10.5121/ijdms.2010.2205
null
cs.DB
http://creativecommons.org/licenses/by-nc-sa/3.0/
There have been many recent studies on sequential pattern mining. The sequential pattern mining on progressive databases is relatively very new, in which we progressively discover the sequential patterns in period of interest. Period of interest is a sliding window continuously advancing as the time goes by. As the focus of sliding window changes, the new items are added to the dataset of interest and obsolete items are removed from it and become up to date. In general, the existing proposals do not fully explore the real world scenario, such as items associated with support in data stream applications such as market basket analysis. Thus mining important knowledge from supported frequent items becomes a non trivial research issue. Our proposed novel approach efficiently mines frequent sequential pattern coupled with support using progressive mining tree.
[ { "version": "v1", "created": "Sat, 29 May 2010 07:38:51 GMT" } ]
2010-07-15T00:00:00
[ [ "Keshavamurthy", "B. N.", "" ], [ "Sharma", "Mitesh", "" ], [ "Toshniwal", "Durga", "" ] ]
TITLE: Efficient Support Coupled Frequent Pattern Mining Over Progressive Databases ABSTRACT: There have been many recent studies on sequential pattern mining. The sequential pattern mining on progressive databases is relatively very new, in which we progressively discover the sequential patterns in period of interest. Period of interest is a sliding window continuously advancing as the time goes by. As the focus of sliding window changes, the new items are added to the dataset of interest and obsolete items are removed from it and become up to date. In general, the existing proposals do not fully explore the real world scenario, such as items associated with support in data stream applications such as market basket analysis. Thus mining important knowledge from supported frequent items becomes a non trivial research issue. Our proposed novel approach efficiently mines frequent sequential pattern coupled with support using progressive mining tree.
no_new_dataset
0.949106
1007.1268
Huy Nguyen
Huy Nguyen and Deokjai Choi
Application of Data Mining to Network Intrusion Detection: Classifier Selection Model
Presented at The 11th Asia-Pacific Network Operations and Management Symposium (APNOMS 2008)
null
null
null
cs.NI cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
As network attacks have increased in number and severity over the past few years, intrusion detection system (IDS) is increasingly becoming a critical component to secure the network. Due to large volumes of security audit data as well as complex and dynamic properties of intrusion behaviors, optimizing performance of IDS becomes an important open problem that is receiving more and more attention from the research community. The uncertainty to explore if certain algorithms perform better for certain attack classes constitutes the motivation for the reported herein. In this paper, we evaluate performance of a comprehensive set of classifier algorithms using KDD99 dataset. Based on evaluation results, best algorithms for each attack category is chosen and two classifier algorithm selection models are proposed. The simulation result comparison indicates that noticeable performance improvement and real-time intrusion detection can be achieved as we apply the proposed models to detect different kinds of network attacks.
[ { "version": "v1", "created": "Thu, 8 Jul 2010 00:23:40 GMT" } ]
2010-07-09T00:00:00
[ [ "Nguyen", "Huy", "" ], [ "Choi", "Deokjai", "" ] ]
TITLE: Application of Data Mining to Network Intrusion Detection: Classifier Selection Model ABSTRACT: As network attacks have increased in number and severity over the past few years, intrusion detection system (IDS) is increasingly becoming a critical component to secure the network. Due to large volumes of security audit data as well as complex and dynamic properties of intrusion behaviors, optimizing performance of IDS becomes an important open problem that is receiving more and more attention from the research community. The uncertainty to explore if certain algorithms perform better for certain attack classes constitutes the motivation for the reported herein. In this paper, we evaluate performance of a comprehensive set of classifier algorithms using KDD99 dataset. Based on evaluation results, best algorithms for each attack category is chosen and two classifier algorithm selection models are proposed. The simulation result comparison indicates that noticeable performance improvement and real-time intrusion detection can be achieved as we apply the proposed models to detect different kinds of network attacks.
no_new_dataset
0.948775
0803.1568
Uwe Aickelin
Qi Chen and Uwe Aickelin
Dempster-Shafer for Anomaly Detection
null
Proceedings of the International Conference on Data Mining (DMIN 2006), pp 232-238, Las Vegas, USA 2006
null
null
cs.NE cs.AI cs.CR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we implement an anomaly detection system using the Dempster-Shafer method. Using two standard benchmark problems we show that by combining multiple signals it is possible to achieve better results than by using a single signal. We further show that by applying this approach to a real-world email dataset the algorithm works for email worm detection. Dempster-Shafer can be a promising method for anomaly detection problems with multiple features (data sources), and two or more classes.
[ { "version": "v1", "created": "Tue, 11 Mar 2008 12:39:01 GMT" } ]
2010-07-05T00:00:00
[ [ "Chen", "Qi", "" ], [ "Aickelin", "Uwe", "" ] ]
TITLE: Dempster-Shafer for Anomaly Detection ABSTRACT: In this paper, we implement an anomaly detection system using the Dempster-Shafer method. Using two standard benchmark problems we show that by combining multiple signals it is possible to achieve better results than by using a single signal. We further show that by applying this approach to a real-world email dataset the algorithm works for email worm detection. Dempster-Shafer can be a promising method for anomaly detection problems with multiple features (data sources), and two or more classes.
no_new_dataset
0.945701
0803.2973
Uwe Aickelin
Uwe Aickelin, Jamie Twycross and Thomas Hesketh-Roberts
Rule Generalisation in Intrusion Detection Systems using Snort
null
International Journal of Electronic Security and Digital Forensics, 1 (1), pp 101-116, 2007
10.1504/IJESDF.2007.013596,
null
cs.NE cs.CR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Intrusion Detection Systems (ids)provide an important layer of security for computer systems and networks, and are becoming more and more necessary as reliance on Internet services increases and systems with sensitive data are more commonly open to Internet access. An ids responsibility is to detect suspicious or unacceptable system and network activity and to alert a systems administrator to this activity. The majority of ids use a set of signatures that define what suspicious traffic is, and Snort is one popular and actively developing open-source ids that uses such a set of signatures known as Snort rules. Our aim is to identify a way in which Snort could be developed further by generalising rules to identify novel attacks. In particular, we attempted to relax and vary the conditions and parameters of current Snort rules, using a similar approach to classic rule learning operators such as generalisation and specialisation. We demonstrate the effectiveness of our approach through experiments with standard datasets and show that we are able to detect previously undeleted variants of various attacks. We conclude by discussing the general effectiveness and appropriateness of generalisation in Snort based ids rule processing.
[ { "version": "v1", "created": "Thu, 20 Mar 2008 11:59:27 GMT" }, { "version": "v2", "created": "Fri, 16 May 2008 10:42:09 GMT" } ]
2010-07-05T00:00:00
[ [ "Aickelin", "Uwe", "" ], [ "Twycross", "Jamie", "" ], [ "Hesketh-Roberts", "Thomas", "" ] ]
TITLE: Rule Generalisation in Intrusion Detection Systems using Snort ABSTRACT: Intrusion Detection Systems (ids)provide an important layer of security for computer systems and networks, and are becoming more and more necessary as reliance on Internet services increases and systems with sensitive data are more commonly open to Internet access. An ids responsibility is to detect suspicious or unacceptable system and network activity and to alert a systems administrator to this activity. The majority of ids use a set of signatures that define what suspicious traffic is, and Snort is one popular and actively developing open-source ids that uses such a set of signatures known as Snort rules. Our aim is to identify a way in which Snort could be developed further by generalising rules to identify novel attacks. In particular, we attempted to relax and vary the conditions and parameters of current Snort rules, using a similar approach to classic rule learning operators such as generalisation and specialisation. We demonstrate the effectiveness of our approach through experiments with standard datasets and show that we are able to detect previously undeleted variants of various attacks. We conclude by discussing the general effectiveness and appropriateness of generalisation in Snort based ids rule processing.
no_new_dataset
0.940626
1004.3708
Uwe Aickelin
Yongnan Ji, Pierre-Yves Herve, Uwe Aickelin, Alain Pitiot
Parcellation of fMRI Datasets with ICA and PLS-A Data Driven Approach
8 pages, 5 figures, P12th International Conference of Medical Image Computing and Computer-Assisted Intervention (MICCAI 2009)
Proceedings of the 12th International Conference of Medical Image Computing and Computer-Assisted Intervention (MICCAI 2009), Part I, Lecture Notes in Computer Science 5761, London, UK, 2009
null
null
cs.CV cs.AI cs.NE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Inter-subject parcellation of functional Magnetic Resonance Imaging (fMRI) data based on a standard General Linear Model (GLM)and spectral clustering was recently proposed as a means to alleviate the issues associated with spatial normalization in fMRI. However, for all its appeal, a GLM-based parcellation approach introduces its own biases, in the form of a priori knowledge about the shape of Hemodynamic Response Function (HRF) and task-related signal changes, or about the subject behaviour during the task. In this paper, we introduce a data-driven version of the spectral clustering parcellation, based on Independent Component Analysis (ICA) and Partial Least Squares (PLS) instead of the GLM. First, a number of independent components are automatically selected. Seed voxels are then obtained from the associated ICA maps and we compute the PLS latent variables between the fMRI signal of the seed voxels (which covers regional variations of the HRF) and the principal components of the signal across all voxels. Finally, we parcellate all subjects data with a spectral clustering of the PLS latent variables. We present results of the application of the proposed method on both single-subject and multi-subject fMRI datasets. Preliminary experimental results, evaluated with intra-parcel variance of GLM t-values and PLS derived t-values, indicate that this data-driven approach offers improvement in terms of parcellation accuracy over GLM based techniques.
[ { "version": "v1", "created": "Wed, 21 Apr 2010 13:50:55 GMT" } ]
2010-07-05T00:00:00
[ [ "Ji", "Yongnan", "" ], [ "Herve", "Pierre-Yves", "" ], [ "Aickelin", "Uwe", "" ], [ "Pitiot", "Alain", "" ] ]
TITLE: Parcellation of fMRI Datasets with ICA and PLS-A Data Driven Approach ABSTRACT: Inter-subject parcellation of functional Magnetic Resonance Imaging (fMRI) data based on a standard General Linear Model (GLM)and spectral clustering was recently proposed as a means to alleviate the issues associated with spatial normalization in fMRI. However, for all its appeal, a GLM-based parcellation approach introduces its own biases, in the form of a priori knowledge about the shape of Hemodynamic Response Function (HRF) and task-related signal changes, or about the subject behaviour during the task. In this paper, we introduce a data-driven version of the spectral clustering parcellation, based on Independent Component Analysis (ICA) and Partial Least Squares (PLS) instead of the GLM. First, a number of independent components are automatically selected. Seed voxels are then obtained from the associated ICA maps and we compute the PLS latent variables between the fMRI signal of the seed voxels (which covers regional variations of the HRF) and the principal components of the signal across all voxels. Finally, we parcellate all subjects data with a spectral clustering of the PLS latent variables. We present results of the application of the proposed method on both single-subject and multi-subject fMRI datasets. Preliminary experimental results, evaluated with intra-parcel variance of GLM t-values and PLS derived t-values, indicate that this data-driven approach offers improvement in terms of parcellation accuracy over GLM based techniques.
no_new_dataset
0.946101
1006.1512
Uwe Aickelin
Julie Greensmith, Uwe Aickelin
The Deterministic Dendritic Cell Algorithm
12 pages, 1 algorithm, 1 figure, 2 tables, 7th International Conference on Artificial Immune Systems (ICARIS 2008)
Proceedings of the 7th International Conference on Artificial Immune Systems (ICARIS 2008), Phuket, Thailand, p 291-303
null
null
cs.AI cs.NE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Dendritic Cell Algorithm is an immune-inspired algorithm orig- inally based on the function of natural dendritic cells. The original instantiation of the algorithm is a highly stochastic algorithm. While the performance of the algorithm is good when applied to large real-time datasets, it is difficult to anal- yse due to the number of random-based elements. In this paper a deterministic version of the algorithm is proposed, implemented and tested using a port scan dataset to provide a controllable system. This version consists of a controllable amount of parameters, which are experimented with in this paper. In addition the effects are examined of the use of time windows and variation on the number of cells, both which are shown to influence the algorithm. Finally a novel metric for the assessment of the algorithms output is introduced and proves to be a more sensitive metric than the metric used with the original Dendritic Cell Algorithm.
[ { "version": "v1", "created": "Tue, 8 Jun 2010 10:07:34 GMT" } ]
2010-07-05T00:00:00
[ [ "Greensmith", "Julie", "" ], [ "Aickelin", "Uwe", "" ] ]
TITLE: The Deterministic Dendritic Cell Algorithm ABSTRACT: The Dendritic Cell Algorithm is an immune-inspired algorithm orig- inally based on the function of natural dendritic cells. The original instantiation of the algorithm is a highly stochastic algorithm. While the performance of the algorithm is good when applied to large real-time datasets, it is difficult to anal- yse due to the number of random-based elements. In this paper a deterministic version of the algorithm is proposed, implemented and tested using a port scan dataset to provide a controllable system. This version consists of a controllable amount of parameters, which are experimented with in this paper. In addition the effects are examined of the use of time windows and variation on the number of cells, both which are shown to influence the algorithm. Finally a novel metric for the assessment of the algorithms output is introduced and proves to be a more sensitive metric than the metric used with the original Dendritic Cell Algorithm.
no_new_dataset
0.948537
1006.5060
Xiaohui Xie
Gui-Bo Ye and Xiaohui Xie
Learning sparse gradients for variable selection and dimension reduction
null
null
null
null
stat.ML cs.LG stat.ME
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Variable selection and dimension reduction are two commonly adopted approaches for high-dimensional data analysis, but have traditionally been treated separately. Here we propose an integrated approach, called sparse gradient learning (SGL), for variable selection and dimension reduction via learning the gradients of the prediction function directly from samples. By imposing a sparsity constraint on the gradients, variable selection is achieved by selecting variables corresponding to non-zero partial derivatives, and effective dimensions are extracted based on the eigenvectors of the derived sparse empirical gradient covariance matrix. An error analysis is given for the convergence of the estimated gradients to the true ones in both the Euclidean and the manifold setting. We also develop an efficient forward-backward splitting algorithm to solve the SGL problem, making the framework practically scalable for medium or large datasets. The utility of SGL for variable selection and feature extraction is explicitly given and illustrated on artificial data as well as real-world examples. The main advantages of our method include variable selection for both linear and nonlinear predictions, effective dimension reduction with sparse loadings, and an efficient algorithm for large p, small n problems.
[ { "version": "v1", "created": "Fri, 25 Jun 2010 20:27:00 GMT" }, { "version": "v2", "created": "Thu, 1 Jul 2010 05:06:43 GMT" } ]
2010-07-02T00:00:00
[ [ "Ye", "Gui-Bo", "" ], [ "Xie", "Xiaohui", "" ] ]
TITLE: Learning sparse gradients for variable selection and dimension reduction ABSTRACT: Variable selection and dimension reduction are two commonly adopted approaches for high-dimensional data analysis, but have traditionally been treated separately. Here we propose an integrated approach, called sparse gradient learning (SGL), for variable selection and dimension reduction via learning the gradients of the prediction function directly from samples. By imposing a sparsity constraint on the gradients, variable selection is achieved by selecting variables corresponding to non-zero partial derivatives, and effective dimensions are extracted based on the eigenvectors of the derived sparse empirical gradient covariance matrix. An error analysis is given for the convergence of the estimated gradients to the true ones in both the Euclidean and the manifold setting. We also develop an efficient forward-backward splitting algorithm to solve the SGL problem, making the framework practically scalable for medium or large datasets. The utility of SGL for variable selection and feature extraction is explicitly given and illustrated on artificial data as well as real-world examples. The main advantages of our method include variable selection for both linear and nonlinear predictions, effective dimension reduction with sparse loadings, and an efficient algorithm for large p, small n problems.
no_new_dataset
0.947039
1005.4032
Debotosh Bhattacharjee
Sandhya Arora, Debotosh Bhattacharjee, Mita Nasipuri, Dipak Kumar Basu, and Mahantapas Kundu
Combining Multiple Feature Extraction Techniques for Handwritten Devnagari Character Recognition
6 pages, 8-10 December 2008
ICIIS 2008
null
null
cs.CV cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we present an OCR for Handwritten Devnagari Characters. Basic symbols are recognized by neural classifier. We have used four feature extraction techniques namely, intersection, shadow feature, chain code histogram and straight line fitting features. Shadow features are computed globally for character image while intersection features, chain code histogram features and line fitting features are computed by dividing the character image into different segments. Weighted majority voting technique is used for combining the classification decision obtained from four Multi Layer Perceptron(MLP) based classifier. On experimentation with a dataset of 4900 samples the overall recognition rate observed is 92.80% as we considered top five choices results. This method is compared with other recent methods for Handwritten Devnagari Character Recognition and it has been observed that this approach has better success rate than other methods.
[ { "version": "v1", "created": "Fri, 21 May 2010 17:57:50 GMT" } ]
2010-07-01T00:00:00
[ [ "Arora", "Sandhya", "" ], [ "Bhattacharjee", "Debotosh", "" ], [ "Nasipuri", "Mita", "" ], [ "Basu", "Dipak Kumar", "" ], [ "Kundu", "Mahantapas", "" ] ]
TITLE: Combining Multiple Feature Extraction Techniques for Handwritten Devnagari Character Recognition ABSTRACT: In this paper we present an OCR for Handwritten Devnagari Characters. Basic symbols are recognized by neural classifier. We have used four feature extraction techniques namely, intersection, shadow feature, chain code histogram and straight line fitting features. Shadow features are computed globally for character image while intersection features, chain code histogram features and line fitting features are computed by dividing the character image into different segments. Weighted majority voting technique is used for combining the classification decision obtained from four Multi Layer Perceptron(MLP) based classifier. On experimentation with a dataset of 4900 samples the overall recognition rate observed is 92.80% as we considered top five choices results. This method is compared with other recent methods for Handwritten Devnagari Character Recognition and it has been observed that this approach has better success rate than other methods.
no_new_dataset
0.946695
1006.5913
Debotosh Bhattacharjee
Sandhya Arora, Debotosh Bhattacharjee, Mita Nasipuri, Dipak Kumar Basu, and Mahantapas Kundu
Multiple Classifier Combination for Off-line Handwritten Devnagari Character Recognition
null
ICSC 2008
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This work presents the application of weighted majority voting technique for combination of classification decision obtained from three Multi_Layer Perceptron(MLP) based classifiers for Recognition of Handwritten Devnagari characters using three different feature sets. The features used are intersection, shadow feature and chain code histogram features. Shadow features are computed globally for character image while intersection features and chain code histogram features are computed by dividing the character image into different segments. On experimentation with a dataset of 4900 samples the overall recognition rate observed is 92.16% as we considered top five choices results. This method is compared with other recent methods for Handwritten Devnagari Character Recognition and it has been observed that this approach has better success rate than other methods.
[ { "version": "v1", "created": "Wed, 30 Jun 2010 16:38:02 GMT" } ]
2010-07-01T00:00:00
[ [ "Arora", "Sandhya", "" ], [ "Bhattacharjee", "Debotosh", "" ], [ "Nasipuri", "Mita", "" ], [ "Basu", "Dipak Kumar", "" ], [ "Kundu", "Mahantapas", "" ] ]
TITLE: Multiple Classifier Combination for Off-line Handwritten Devnagari Character Recognition ABSTRACT: This work presents the application of weighted majority voting technique for combination of classification decision obtained from three Multi_Layer Perceptron(MLP) based classifiers for Recognition of Handwritten Devnagari characters using three different feature sets. The features used are intersection, shadow feature and chain code histogram features. Shadow features are computed globally for character image while intersection features and chain code histogram features are computed by dividing the character image into different segments. On experimentation with a dataset of 4900 samples the overall recognition rate observed is 92.16% as we considered top five choices results. This method is compared with other recent methods for Handwritten Devnagari Character Recognition and it has been observed that this approach has better success rate than other methods.
no_new_dataset
0.940626
1006.5927
Debotosh Bhattacharjee
Sandhya Arora, Latesh Malik, Debotosh Bhattacharjee, and Mita Nasipuri
Classification Of Gradient Change Features Using MLP For Handwritten Character Recognition
null
EAIT 2006
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A novel, generic scheme for off-line handwritten English alphabets character images is proposed. The advantage of the technique is that it can be applied in a generic manner to different applications and is expected to perform better in uncertain and noisy environments. The recognition scheme is using a multilayer perceptron(MLP) neural networks. The system was trained and tested on a database of 300 samples of handwritten characters. For improved generalization and to avoid overtraining, the whole available dataset has been divided into two subsets: training set and test set. We achieved 99.10% and 94.15% correct recognition rates on training and test sets respectively. The purposed scheme is robust with respect to various writing styles and size as well as presence of considerable noise.
[ { "version": "v1", "created": "Wed, 30 Jun 2010 17:14:40 GMT" } ]
2010-07-01T00:00:00
[ [ "Arora", "Sandhya", "" ], [ "Malik", "Latesh", "" ], [ "Bhattacharjee", "Debotosh", "" ], [ "Nasipuri", "Mita", "" ] ]
TITLE: Classification Of Gradient Change Features Using MLP For Handwritten Character Recognition ABSTRACT: A novel, generic scheme for off-line handwritten English alphabets character images is proposed. The advantage of the technique is that it can be applied in a generic manner to different applications and is expected to perform better in uncertain and noisy environments. The recognition scheme is using a multilayer perceptron(MLP) neural networks. The system was trained and tested on a database of 300 samples of handwritten characters. For improved generalization and to avoid overtraining, the whole available dataset has been divided into two subsets: training set and test set. We achieved 99.10% and 94.15% correct recognition rates on training and test sets respectively. The purposed scheme is robust with respect to various writing styles and size as well as presence of considerable noise.
no_new_dataset
0.941922
1006.5188
Nicola Di Mauro
Nicola Di Mauro and Teresa M.A. Basile and Stefano Ferilli and Floriana Esposito
Feature Construction for Relational Sequence Learning
15 pages
null
null
null
cs.AI cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We tackle the problem of multi-class relational sequence learning using relevant patterns discovered from a set of labelled sequences. To deal with this problem, firstly each relational sequence is mapped into a feature vector using the result of a feature construction method. Since, the efficacy of sequence learning algorithms strongly depends on the features used to represent the sequences, the second step is to find an optimal subset of the constructed features leading to high classification accuracy. This feature selection task has been solved adopting a wrapper approach that uses a stochastic local search algorithm embedding a naive Bayes classifier. The performance of the proposed method applied to a real-world dataset shows an improvement when compared to other established methods, such as hidden Markov models, Fisher kernels and conditional random fields for relational sequences.
[ { "version": "v1", "created": "Sun, 27 Jun 2010 08:56:11 GMT" } ]
2010-06-29T00:00:00
[ [ "Di Mauro", "Nicola", "" ], [ "Basile", "Teresa M. A.", "" ], [ "Ferilli", "Stefano", "" ], [ "Esposito", "Floriana", "" ] ]
TITLE: Feature Construction for Relational Sequence Learning ABSTRACT: We tackle the problem of multi-class relational sequence learning using relevant patterns discovered from a set of labelled sequences. To deal with this problem, firstly each relational sequence is mapped into a feature vector using the result of a feature construction method. Since, the efficacy of sequence learning algorithms strongly depends on the features used to represent the sequences, the second step is to find an optimal subset of the constructed features leading to high classification accuracy. This feature selection task has been solved adopting a wrapper approach that uses a stochastic local search algorithm embedding a naive Bayes classifier. The performance of the proposed method applied to a real-world dataset shows an improvement when compared to other established methods, such as hidden Markov models, Fisher kernels and conditional random fields for relational sequences.
no_new_dataset
0.948298
1006.5041
Yoshinobu Kawahara
Yoshinobu Kawahara, Kenneth Bollen, Shohei Shimizu and Takashi Washio
GroupLiNGAM: Linear non-Gaussian acyclic models for sets of variables
null
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Finding the structure of a graphical model has been received much attention in many fields. Recently, it is reported that the non-Gaussianity of data enables us to identify the structure of a directed acyclic graph without any prior knowledge on the structure. In this paper, we propose a novel non-Gaussianity based algorithm for more general type of models; chain graphs. The algorithm finds an ordering of the disjoint subsets of variables by iteratively evaluating the independence between the variable subset and the residuals when the remaining variables are regressed on those. However, its computational cost grows exponentially according to the number of variables. Therefore, we further discuss an efficient approximate approach for applying the algorithm to large sized graphs. We illustrate the algorithm with artificial and real-world datasets.
[ { "version": "v1", "created": "Thu, 24 Jun 2010 13:09:36 GMT" } ]
2010-06-28T00:00:00
[ [ "Kawahara", "Yoshinobu", "" ], [ "Bollen", "Kenneth", "" ], [ "Shimizu", "Shohei", "" ], [ "Washio", "Takashi", "" ] ]
TITLE: GroupLiNGAM: Linear non-Gaussian acyclic models for sets of variables ABSTRACT: Finding the structure of a graphical model has been received much attention in many fields. Recently, it is reported that the non-Gaussianity of data enables us to identify the structure of a directed acyclic graph without any prior knowledge on the structure. In this paper, we propose a novel non-Gaussianity based algorithm for more general type of models; chain graphs. The algorithm finds an ordering of the disjoint subsets of variables by iteratively evaluating the independence between the variable subset and the residuals when the remaining variables are regressed on those. However, its computational cost grows exponentially according to the number of variables. Therefore, we further discuss an efficient approximate approach for applying the algorithm to large sized graphs. We illustrate the algorithm with artificial and real-world datasets.
no_new_dataset
0.949201
1006.5051
Ping Li
Ping Li
Fast ABC-Boost for Multi-Class Classification
null
null
null
null
cs.LG stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Abc-boost is a new line of boosting algorithms for multi-class classification, by utilizing the commonly used sum-to-zero constraint. To implement abc-boost, a base class must be identified at each boosting step. Prior studies used a very expensive procedure based on exhaustive search for determining the base class at each boosting step. Good testing performances of abc-boost (implemented as abc-mart and abc-logitboost) on a variety of datasets were reported. For large datasets, however, the exhaustive search strategy adopted in prior abc-boost algorithms can be too prohibitive. To overcome this serious limitation, this paper suggests a heuristic by introducing Gaps when computing the base class during training. That is, we update the choice of the base class only for every $G$ boosting steps (i.e., G=1 in prior studies). We test this idea on large datasets (Covertype and Poker) as well as datasets of moderate sizes. Our preliminary results are very encouraging. On the large datasets, even with G=100 (or larger), there is essentially no loss of test accuracy. On the moderate datasets, no obvious loss of test accuracy is observed when G<= 20~50. Therefore, aided by this heuristic, it is promising that abc-boost will be a practical tool for accurate multi-class classification.
[ { "version": "v1", "created": "Fri, 25 Jun 2010 19:48:50 GMT" } ]
2010-06-28T00:00:00
[ [ "Li", "Ping", "" ] ]
TITLE: Fast ABC-Boost for Multi-Class Classification ABSTRACT: Abc-boost is a new line of boosting algorithms for multi-class classification, by utilizing the commonly used sum-to-zero constraint. To implement abc-boost, a base class must be identified at each boosting step. Prior studies used a very expensive procedure based on exhaustive search for determining the base class at each boosting step. Good testing performances of abc-boost (implemented as abc-mart and abc-logitboost) on a variety of datasets were reported. For large datasets, however, the exhaustive search strategy adopted in prior abc-boost algorithms can be too prohibitive. To overcome this serious limitation, this paper suggests a heuristic by introducing Gaps when computing the base class during training. That is, we update the choice of the base class only for every $G$ boosting steps (i.e., G=1 in prior studies). We test this idea on large datasets (Covertype and Poker) as well as datasets of moderate sizes. Our preliminary results are very encouraging. On the large datasets, even with G=100 (or larger), there is essentially no loss of test accuracy. On the moderate datasets, no obvious loss of test accuracy is observed when G<= 20~50. Therefore, aided by this heuristic, it is promising that abc-boost will be a practical tool for accurate multi-class classification.
no_new_dataset
0.947137
1006.4540
William Jackson
N. Suguna and K. Thanushkodi
A Novel Rough Set Reduct Algorithm for Medical Domain Based on Bee Colony Optimization
IEEE Publication Format, https://sites.google.com/site/journalofcomputing/
Journal of Computing, Vol. 2, No. 6, June 2010, NY, USA, ISSN 2151-9617
null
null
cs.LG cs.AI cs.NE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Feature selection refers to the problem of selecting relevant features which produce the most predictive outcome. In particular, feature selection task is involved in datasets containing huge number of features. Rough set theory has been one of the most successful methods used for feature selection. However, this method is still not able to find optimal subsets. This paper proposes a new feature selection method based on Rough set theory hybrid with Bee Colony Optimization (BCO) in an attempt to combat this. This proposed work is applied in the medical domain to find the minimal reducts and experimentally compared with the Quick Reduct, Entropy Based Reduct, and other hybrid Rough Set methods such as Genetic Algorithm (GA), Ant Colony Optimization (ACO) and Particle Swarm Optimization (PSO).
[ { "version": "v1", "created": "Wed, 23 Jun 2010 14:53:33 GMT" } ]
2010-06-24T00:00:00
[ [ "Suguna", "N.", "" ], [ "Thanushkodi", "K.", "" ] ]
TITLE: A Novel Rough Set Reduct Algorithm for Medical Domain Based on Bee Colony Optimization ABSTRACT: Feature selection refers to the problem of selecting relevant features which produce the most predictive outcome. In particular, feature selection task is involved in datasets containing huge number of features. Rough set theory has been one of the most successful methods used for feature selection. However, this method is still not able to find optimal subsets. This paper proposes a new feature selection method based on Rough set theory hybrid with Bee Colony Optimization (BCO) in an attempt to combat this. This proposed work is applied in the medical domain to find the minimal reducts and experimentally compared with the Quick Reduct, Entropy Based Reduct, and other hybrid Rough Set methods such as Genetic Algorithm (GA), Ant Colony Optimization (ACO) and Particle Swarm Optimization (PSO).
no_new_dataset
0.951097
1006.3679
Hossein Mobahi
Hossein Mobahi, Shankar R. Rao, Allen Y. Yang, Shankar S. Sastry and Yi Ma
Segmentation of Natural Images by Texture and Boundary Compression
null
null
null
null
cs.CV cs.IT cs.LG math.IT
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a novel algorithm for segmentation of natural images that harnesses the principle of minimum description length (MDL). Our method is based on observations that a homogeneously textured region of a natural image can be well modeled by a Gaussian distribution and the region boundary can be effectively coded by an adaptive chain code. The optimal segmentation of an image is the one that gives the shortest coding length for encoding all textures and boundaries in the image, and is obtained via an agglomerative clustering process applied to a hierarchy of decreasing window sizes as multi-scale texture features. The optimal segmentation also provides an accurate estimate of the overall coding length and hence the true entropy of the image. We test our algorithm on the publicly available Berkeley Segmentation Dataset. It achieves state-of-the-art segmentation results compared to other existing methods.
[ { "version": "v1", "created": "Fri, 18 Jun 2010 12:37:28 GMT" } ]
2010-06-21T00:00:00
[ [ "Mobahi", "Hossein", "" ], [ "Rao", "Shankar R.", "" ], [ "Yang", "Allen Y.", "" ], [ "Sastry", "Shankar S.", "" ], [ "Ma", "Yi", "" ] ]
TITLE: Segmentation of Natural Images by Texture and Boundary Compression ABSTRACT: We present a novel algorithm for segmentation of natural images that harnesses the principle of minimum description length (MDL). Our method is based on observations that a homogeneously textured region of a natural image can be well modeled by a Gaussian distribution and the region boundary can be effectively coded by an adaptive chain code. The optimal segmentation of an image is the one that gives the shortest coding length for encoding all textures and boundaries in the image, and is obtained via an agglomerative clustering process applied to a hierarchy of decreasing window sizes as multi-scale texture features. The optimal segmentation also provides an accurate estimate of the overall coding length and hence the true entropy of the image. We test our algorithm on the publicly available Berkeley Segmentation Dataset. It achieves state-of-the-art segmentation results compared to other existing methods.
no_new_dataset
0.949435
1006.2734
Ariel Baya
Ariel E. Baya and Pablo M. Granitto
Penalized K-Nearest-Neighbor-Graph Based Metrics for Clustering
null
null
null
null
cs.CV
http://creativecommons.org/licenses/by-nc-sa/3.0/
A difficult problem in clustering is how to handle data with a manifold structure, i.e. data that is not shaped in the form of compact clouds of points, forming arbitrary shapes or paths embedded in a high-dimensional space. In this work we introduce the Penalized k-Nearest-Neighbor-Graph (PKNNG) based metric, a new tool for evaluating distances in such cases. The new metric can be used in combination with most clustering algorithms. The PKNNG metric is based on a two-step procedure: first it constructs the k-Nearest-Neighbor-Graph of the dataset of interest using a low k-value and then it adds edges with an exponentially penalized weight for connecting the sub-graphs produced by the first step. We discuss several possible schemes for connecting the different sub-graphs. We use three artificial datasets in four different embedding situations to evaluate the behavior of the new metric, including a comparison among different clustering methods. We also evaluate the new metric in a real world application, clustering the MNIST digits dataset. In all cases the PKNNG metric shows promising clustering results.
[ { "version": "v1", "created": "Mon, 14 Jun 2010 15:07:45 GMT" } ]
2010-06-15T00:00:00
[ [ "Baya", "Ariel E.", "" ], [ "Granitto", "Pablo M.", "" ] ]
TITLE: Penalized K-Nearest-Neighbor-Graph Based Metrics for Clustering ABSTRACT: A difficult problem in clustering is how to handle data with a manifold structure, i.e. data that is not shaped in the form of compact clouds of points, forming arbitrary shapes or paths embedded in a high-dimensional space. In this work we introduce the Penalized k-Nearest-Neighbor-Graph (PKNNG) based metric, a new tool for evaluating distances in such cases. The new metric can be used in combination with most clustering algorithms. The PKNNG metric is based on a two-step procedure: first it constructs the k-Nearest-Neighbor-Graph of the dataset of interest using a low k-value and then it adds edges with an exponentially penalized weight for connecting the sub-graphs produced by the first step. We discuss several possible schemes for connecting the different sub-graphs. We use three artificial datasets in four different embedding situations to evaluate the behavior of the new metric, including a comparison among different clustering methods. We also evaluate the new metric in a real world application, clustering the MNIST digits dataset. In all cases the PKNNG metric shows promising clustering results.
no_new_dataset
0.952882
1005.5516
David J Brenes
David J. Brenes, Daniel Gayo-Avello and Rodrigo Garcia
On the Fly Query Entity Decomposition Using Snippets
Extended version of paper submitted to CERI 2010
null
null
null
cs.IR
http://creativecommons.org/licenses/by-nc-sa/3.0/
One of the most important issues in Information Retrieval is inferring the intents underlying users' queries. Thus, any tool to enrich or to better contextualized queries can proof extremely valuable. Entity extraction, provided it is done fast, can be one of such tools. Such techniques usually rely on a prior training phase involving large datasets. That training is costly, specially in environments which are increasingly moving towards real time scenarios where latency to retrieve fresh informacion should be minimal. In this paper an `on-the-fly' query decomposition method is proposed. It uses snippets which are mined by means of a na\"ive statistical algorithm. An initial evaluation of such a method is provided, in addition to a discussion on its applicability to different scenarios.
[ { "version": "v1", "created": "Sun, 30 May 2010 11:41:43 GMT" }, { "version": "v2", "created": "Sun, 6 Jun 2010 11:36:05 GMT" } ]
2010-06-14T00:00:00
[ [ "Brenes", "David J.", "" ], [ "Gayo-Avello", "Daniel", "" ], [ "Garcia", "Rodrigo", "" ] ]
TITLE: On the Fly Query Entity Decomposition Using Snippets ABSTRACT: One of the most important issues in Information Retrieval is inferring the intents underlying users' queries. Thus, any tool to enrich or to better contextualized queries can proof extremely valuable. Entity extraction, provided it is done fast, can be one of such tools. Such techniques usually rely on a prior training phase involving large datasets. That training is costly, specially in environments which are increasingly moving towards real time scenarios where latency to retrieve fresh informacion should be minimal. In this paper an `on-the-fly' query decomposition method is proposed. It uses snippets which are mined by means of a na\"ive statistical algorithm. An initial evaluation of such a method is provided, in addition to a discussion on its applicability to different scenarios.
no_new_dataset
0.946843
1006.2156
Aditya Menon
Aditya Krishna Menon and Charles Elkan
Dyadic Prediction Using a Latent Feature Log-Linear Model
null
null
null
null
cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In dyadic prediction, labels must be predicted for pairs (dyads) whose members possess unique identifiers and, sometimes, additional features called side-information. Special cases of this problem include collaborative filtering and link prediction. We present the first model for dyadic prediction that satisfies several important desiderata: (i) labels may be ordinal or nominal, (ii) side-information can be easily exploited if present, (iii) with or without side-information, latent features are inferred for dyad members, (iv) it is resistant to sample-selection bias, (v) it can learn well-calibrated probabilities, and (vi) it can scale to very large datasets. To our knowledge, no existing method satisfies all the above criteria. In particular, many methods assume that the labels are ordinal and ignore side-information when it is present. Experimental results show that the new method is competitive with state-of-the-art methods for the special cases of collaborative filtering and link prediction, and that it makes accurate predictions on nominal data.
[ { "version": "v1", "created": "Thu, 10 Jun 2010 21:19:28 GMT" } ]
2010-06-14T00:00:00
[ [ "Menon", "Aditya Krishna", "" ], [ "Elkan", "Charles", "" ] ]
TITLE: Dyadic Prediction Using a Latent Feature Log-Linear Model ABSTRACT: In dyadic prediction, labels must be predicted for pairs (dyads) whose members possess unique identifiers and, sometimes, additional features called side-information. Special cases of this problem include collaborative filtering and link prediction. We present the first model for dyadic prediction that satisfies several important desiderata: (i) labels may be ordinal or nominal, (ii) side-information can be easily exploited if present, (iii) with or without side-information, latent features are inferred for dyad members, (iv) it is resistant to sample-selection bias, (v) it can learn well-calibrated probabilities, and (vi) it can scale to very large datasets. To our knowledge, no existing method satisfies all the above criteria. In particular, many methods assume that the labels are ordinal and ignore side-information when it is present. Experimental results show that the new method is competitive with state-of-the-art methods for the special cases of collaborative filtering and link prediction, and that it makes accurate predictions on nominal data.
no_new_dataset
0.950088
1006.1702
Munmun De Choudhury
Munmun De Choudhury, Hari Sundaram, Ajita John, Doree Duncan Seligmann, Aisling Kelliher
"Birds of a Feather": Does User Homophily Impact Information Diffusion in Social Media?
31 pages, 10 figures, 3 tables
null
null
null
cs.CY physics.soc-ph
http://creativecommons.org/licenses/by-nc-sa/3.0/
This article investigates the impact of user homophily on the social process of information diffusion in online social media. Over several decades, social scientists have been interested in the idea that similarity breeds connection: precisely known as "homophily". Homophily has been extensively studied in the social sciences and refers to the idea that users in a social system tend to bond more with ones who are similar to them than to ones who are dissimilar. The key observation is that homophily structures the ego-networks of individuals and impacts their communication behavior. It is therefore likely to effect the mechanisms in which information propagates among them. To this effect, we investigate the interplay between homophily along diverse user attributes and the information diffusion process on social media. In our approach, we first extract diffusion characteristics---corresponding to the baseline social graph as well as graphs filtered on different user attributes (e.g. location, activity). Second, we propose a Dynamic Bayesian Network based framework to predict diffusion characteristics at a future time. Third, the impact of attribute homophily is quantified by the ability of the predicted characteristics in explaining actual diffusion, and external variables, including trends in search and news. Experimental results on a large Twitter dataset demonstrate that choice of the homophilous attribute can impact the prediction of information diffusion, given a specific metric and a topic. In most cases, attribute homophily is able to explain the actual diffusion and external trends by ~15-25% over cases when homophily is not considered.
[ { "version": "v1", "created": "Wed, 9 Jun 2010 04:19:20 GMT" } ]
2010-06-10T00:00:00
[ [ "De Choudhury", "Munmun", "" ], [ "Sundaram", "Hari", "" ], [ "John", "Ajita", "" ], [ "Seligmann", "Doree Duncan", "" ], [ "Kelliher", "Aisling", "" ] ]
TITLE: "Birds of a Feather": Does User Homophily Impact Information Diffusion in Social Media? ABSTRACT: This article investigates the impact of user homophily on the social process of information diffusion in online social media. Over several decades, social scientists have been interested in the idea that similarity breeds connection: precisely known as "homophily". Homophily has been extensively studied in the social sciences and refers to the idea that users in a social system tend to bond more with ones who are similar to them than to ones who are dissimilar. The key observation is that homophily structures the ego-networks of individuals and impacts their communication behavior. It is therefore likely to effect the mechanisms in which information propagates among them. To this effect, we investigate the interplay between homophily along diverse user attributes and the information diffusion process on social media. In our approach, we first extract diffusion characteristics---corresponding to the baseline social graph as well as graphs filtered on different user attributes (e.g. location, activity). Second, we propose a Dynamic Bayesian Network based framework to predict diffusion characteristics at a future time. Third, the impact of attribute homophily is quantified by the ability of the predicted characteristics in explaining actual diffusion, and external variables, including trends in search and news. Experimental results on a large Twitter dataset demonstrate that choice of the homophilous attribute can impact the prediction of information diffusion, given a specific metric and a topic. In most cases, attribute homophily is able to explain the actual diffusion and external trends by ~15-25% over cases when homophily is not considered.
no_new_dataset
0.951818
1006.1328
Jonathan Huang
Jonathan Huang and Carlos Guestrin
Uncovering the Riffled Independence Structure of Rankings
65 pages
null
null
null
cs.LG cs.AI stat.AP stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Representing distributions over permutations can be a daunting task due to the fact that the number of permutations of $n$ objects scales factorially in $n$. One recent way that has been used to reduce storage complexity has been to exploit probabilistic independence, but as we argue, full independence assumptions impose strong sparsity constraints on distributions and are unsuitable for modeling rankings. We identify a novel class of independence structures, called \emph{riffled independence}, encompassing a more expressive family of distributions while retaining many of the properties necessary for performing efficient inference and reducing sample complexity. In riffled independence, one draws two permutations independently, then performs the \emph{riffle shuffle}, common in card games, to combine the two permutations to form a single permutation. Within the context of ranking, riffled independence corresponds to ranking disjoint sets of objects independently, then interleaving those rankings. In this paper, we provide a formal introduction to riffled independence and present algorithms for using riffled independence within Fourier-theoretic frameworks which have been explored by a number of recent papers. Additionally, we propose an automated method for discovering sets of items which are riffle independent from a training set of rankings. We show that our clustering-like algorithms can be used to discover meaningful latent coalitions from real preference ranking datasets and to learn the structure of hierarchically decomposable models based on riffled independence.
[ { "version": "v1", "created": "Mon, 7 Jun 2010 18:45:46 GMT" } ]
2010-06-08T00:00:00
[ [ "Huang", "Jonathan", "" ], [ "Guestrin", "Carlos", "" ] ]
TITLE: Uncovering the Riffled Independence Structure of Rankings ABSTRACT: Representing distributions over permutations can be a daunting task due to the fact that the number of permutations of $n$ objects scales factorially in $n$. One recent way that has been used to reduce storage complexity has been to exploit probabilistic independence, but as we argue, full independence assumptions impose strong sparsity constraints on distributions and are unsuitable for modeling rankings. We identify a novel class of independence structures, called \emph{riffled independence}, encompassing a more expressive family of distributions while retaining many of the properties necessary for performing efficient inference and reducing sample complexity. In riffled independence, one draws two permutations independently, then performs the \emph{riffle shuffle}, common in card games, to combine the two permutations to form a single permutation. Within the context of ranking, riffled independence corresponds to ranking disjoint sets of objects independently, then interleaving those rankings. In this paper, we provide a formal introduction to riffled independence and present algorithms for using riffled independence within Fourier-theoretic frameworks which have been explored by a number of recent papers. Additionally, we propose an automated method for discovering sets of items which are riffle independent from a training set of rankings. We show that our clustering-like algorithms can be used to discover meaningful latent coalitions from real preference ranking datasets and to learn the structure of hierarchically decomposable models based on riffled independence.
no_new_dataset
0.946151
1005.0390
Adam Gauci
Adam Gauci, Kristian Zarb Adami, John Abela
Machine Learning for Galaxy Morphology Classification
null
null
null
null
astro-ph.GA cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work, decision tree learning algorithms and fuzzy inferencing systems are applied for galaxy morphology classification. In particular, the CART, the C4.5, the Random Forest and fuzzy logic algorithms are studied and reliable classifiers are developed to distinguish between spiral galaxies, elliptical galaxies or star/unknown galactic objects. Morphology information for the training and testing datasets is obtained from the Galaxy Zoo project while the corresponding photometric and spectra parameters are downloaded from the SDSS DR7 catalogue.
[ { "version": "v1", "created": "Mon, 3 May 2010 20:01:38 GMT" }, { "version": "v2", "created": "Tue, 1 Jun 2010 07:54:29 GMT" } ]
2010-06-02T00:00:00
[ [ "Gauci", "Adam", "" ], [ "Adami", "Kristian Zarb", "" ], [ "Abela", "John", "" ] ]
TITLE: Machine Learning for Galaxy Morphology Classification ABSTRACT: In this work, decision tree learning algorithms and fuzzy inferencing systems are applied for galaxy morphology classification. In particular, the CART, the C4.5, the Random Forest and fuzzy logic algorithms are studied and reliable classifiers are developed to distinguish between spiral galaxies, elliptical galaxies or star/unknown galactic objects. Morphology information for the training and testing datasets is obtained from the Galaxy Zoo project while the corresponding photometric and spectra parameters are downloaded from the SDSS DR7 catalogue.
no_new_dataset
0.953362
1005.4963
Anon Plangprasopchok
Anon Plangprasopchok, Kristina Lerman, Lise Getoor
Integrating Structured Metadata with Relational Affinity Propagation
6 Pages, To appear at AAAI Workshop on Statistical Relational AI
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Structured and semi-structured data describing entities, taxonomies and ontologies appears in many domains. There is a huge interest in integrating structured information from multiple sources; however integrating structured data to infer complex common structures is a difficult task because the integration must aggregate similar structures while avoiding structural inconsistencies that may appear when the data is combined. In this work, we study the integration of structured social metadata: shallow personal hierarchies specified by many individual users on the SocialWeb, and focus on inferring a collection of integrated, consistent taxonomies. We frame this task as an optimization problem with structural constraints. We propose a new inference algorithm, which we refer to as Relational Affinity Propagation (RAP) that extends affinity propagation (Frey and Dueck 2007) by introducing structural constraints. We validate the approach on a real-world social media dataset, collected from the photosharing website Flickr. Our empirical results show that our proposed approach is able to construct deeper and denser structures compared to an approach using only the standard affinity propagation algorithm.
[ { "version": "v1", "created": "Wed, 26 May 2010 23:13:05 GMT" } ]
2010-05-28T00:00:00
[ [ "Plangprasopchok", "Anon", "" ], [ "Lerman", "Kristina", "" ], [ "Getoor", "Lise", "" ] ]
TITLE: Integrating Structured Metadata with Relational Affinity Propagation ABSTRACT: Structured and semi-structured data describing entities, taxonomies and ontologies appears in many domains. There is a huge interest in integrating structured information from multiple sources; however integrating structured data to infer complex common structures is a difficult task because the integration must aggregate similar structures while avoiding structural inconsistencies that may appear when the data is combined. In this work, we study the integration of structured social metadata: shallow personal hierarchies specified by many individual users on the SocialWeb, and focus on inferring a collection of integrated, consistent taxonomies. We frame this task as an optimization problem with structural constraints. We propose a new inference algorithm, which we refer to as Relational Affinity Propagation (RAP) that extends affinity propagation (Frey and Dueck 2007) by introducing structural constraints. We validate the approach on a real-world social media dataset, collected from the photosharing website Flickr. Our empirical results show that our proposed approach is able to construct deeper and denser structures compared to an approach using only the standard affinity propagation algorithm.
no_new_dataset
0.948822
1005.5035
Mark Edgington
Mark Edgington, Yohannes Kassahun and Frank Kirchner
Dynamic Motion Modelling for Legged Robots
null
null
10.1109/IROS.2009.5354026
null
cs.RO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
An accurate motion model is an important component in modern-day robotic systems, but building such a model for a complex system often requires an appreciable amount of manual effort. In this paper we present a motion model representation, the Dynamic Gaussian Mixture Model (DGMM), that alleviates the need to manually design the form of a motion model, and provides a direct means of incorporating auxiliary sensory data into the model. This representation and its accompanying algorithms are validated experimentally using an 8-legged kinematically complex robot, as well as a standard benchmark dataset. The presented method not only learns the robot's motion model, but also improves the model's accuracy by incorporating information about the terrain surrounding the robot.
[ { "version": "v1", "created": "Thu, 27 May 2010 11:41:36 GMT" } ]
2010-05-28T00:00:00
[ [ "Edgington", "Mark", "" ], [ "Kassahun", "Yohannes", "" ], [ "Kirchner", "Frank", "" ] ]
TITLE: Dynamic Motion Modelling for Legged Robots ABSTRACT: An accurate motion model is an important component in modern-day robotic systems, but building such a model for a complex system often requires an appreciable amount of manual effort. In this paper we present a motion model representation, the Dynamic Gaussian Mixture Model (DGMM), that alleviates the need to manually design the form of a motion model, and provides a direct means of incorporating auxiliary sensory data into the model. This representation and its accompanying algorithms are validated experimentally using an 8-legged kinematically complex robot, as well as a standard benchmark dataset. The presented method not only learns the robot's motion model, but also improves the model's accuracy by incorporating information about the terrain surrounding the robot.
no_new_dataset
0.9357
1005.4454
Bruce Berriman
Joseph C. Jacob, Daniel S. Katz, G. Bruce Berriman, John Good, Anastasia C. Laity, Ewa Deelman, Carl Kesselman, Gurmeet Singh, Mei-Hui Su, Thomas A. Prince, Roy Williams
Montage: a grid portal and software toolkit for science-grade astronomical image mosaicking
16 pages, 11 figures
Int. J. Computational Science and Engineering. 2009
null
null
astro-ph.IM cs.DC cs.SE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Montage is a portable software toolkit for constructing custom, science-grade mosaics by composing multiple astronomical images. The mosaics constructed by Montage preserve the astrometry (position) and photometry (intensity) of the sources in the input images. The mosaic to be constructed is specified by the user in terms of a set of parameters, including dataset and wavelength to be used, location and size on the sky, coordinate system and projection, and spatial sampling rate. Many astronomical datasets are massive, and are stored in distributed archives that are, in most cases, remote with respect to the available computational resources. Montage can be run on both single- and multi-processor computers, including clusters and grids. Standard grid tools are used to run Montage in the case where the data or computers used to construct a mosaic are located remotely on the Internet. This paper describes the architecture, algorithms, and usage of Montage as both a software toolkit and as a grid portal. Timing results are provided to show how Montage performance scales with number of processors on a cluster computer. In addition, we compare the performance of two methods of running Montage in parallel on a grid.
[ { "version": "v1", "created": "Mon, 24 May 2010 23:28:51 GMT" } ]
2010-05-26T00:00:00
[ [ "Jacob", "Joseph C.", "" ], [ "Katz", "Daniel S.", "" ], [ "Berriman", "G. Bruce", "" ], [ "Good", "John", "" ], [ "Laity", "Anastasia C.", "" ], [ "Deelman", "Ewa", "" ], [ "Kesselman", "Carl", "" ], [ "Singh", "Gurmeet", "" ], [ "Su", "Mei-Hui", "" ], [ "Prince", "Thomas A.", "" ], [ "Williams", "Roy", "" ] ]
TITLE: Montage: a grid portal and software toolkit for science-grade astronomical image mosaicking ABSTRACT: Montage is a portable software toolkit for constructing custom, science-grade mosaics by composing multiple astronomical images. The mosaics constructed by Montage preserve the astrometry (position) and photometry (intensity) of the sources in the input images. The mosaic to be constructed is specified by the user in terms of a set of parameters, including dataset and wavelength to be used, location and size on the sky, coordinate system and projection, and spatial sampling rate. Many astronomical datasets are massive, and are stored in distributed archives that are, in most cases, remote with respect to the available computational resources. Montage can be run on both single- and multi-processor computers, including clusters and grids. Standard grid tools are used to run Montage in the case where the data or computers used to construct a mosaic are located remotely on the Internet. This paper describes the architecture, algorithms, and usage of Montage as both a software toolkit and as a grid portal. Timing results are provided to show how Montage performance scales with number of processors on a cluster computer. In addition, we compare the performance of two methods of running Montage in parallel on a grid.
no_new_dataset
0.951908
0906.2883
Petr Chaloupka
Petr Chaloupka, Pavel Jakl, Jan Kapit\'an, J\'er\^ome Lauret and Michal Zerola
Setting up a STAR Tier 2 Site at Golias/Prague Farm
To appear in proceedings of Computing in High Energy and Nuclear Physics 2009
J.Phys.Conf.Ser.219:072031,2010
10.1088/1742-6596/219/7/072031
null
physics.comp-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
High Energy Nuclear Physics (HENP) collaborations' experience show that the computing resources available at a single site are often neither sufficient nor satisfy the need of remote collaborators. From latencies in the network connectivity to the lack of interactivity, work at distant computing centers is often inefficient. Having fully functional software stack on local resources is a strong enabler of science opportunities for any local group who can afford the time investment. Prague's heavy-ions group participating in STAR experiment at RHIC has been a strong advocate of local computing as the most efficient means of data processing and physics analyses. Tier 2 computing center was set up at a Regional Computing Center for Particle Physics called "Golias". We report on our experience in setting up a fully functional Tier 2 center and discuss the solutions chosen to address storage space and analysis issues and the impact on the farms overall functionality. This includes a locally built STAR analysis framework, integration with a local DPM system (a cost effective storage solution), the influence of the availability and quality of the network connection to Tier 0 via a dedicated CESNET/ESnet link and the development of light-weight yet fully automated data transfer tools allowing the movement of entire datasets from BNL (Tier 0) to Golias (Tier 2).
[ { "version": "v1", "created": "Tue, 16 Jun 2009 09:43:25 GMT" }, { "version": "v2", "created": "Thu, 18 Jun 2009 09:55:28 GMT" } ]
2010-05-25T00:00:00
[ [ "Chaloupka", "Petr", "" ], [ "Jakl", "Pavel", "" ], [ "Kapitán", "Jan", "" ], [ "Lauret", "Jérôme", "" ], [ "Zerola", "Michal", "" ] ]
TITLE: Setting up a STAR Tier 2 Site at Golias/Prague Farm ABSTRACT: High Energy Nuclear Physics (HENP) collaborations' experience show that the computing resources available at a single site are often neither sufficient nor satisfy the need of remote collaborators. From latencies in the network connectivity to the lack of interactivity, work at distant computing centers is often inefficient. Having fully functional software stack on local resources is a strong enabler of science opportunities for any local group who can afford the time investment. Prague's heavy-ions group participating in STAR experiment at RHIC has been a strong advocate of local computing as the most efficient means of data processing and physics analyses. Tier 2 computing center was set up at a Regional Computing Center for Particle Physics called "Golias". We report on our experience in setting up a fully functional Tier 2 center and discuss the solutions chosen to address storage space and analysis issues and the impact on the farms overall functionality. This includes a locally built STAR analysis framework, integration with a local DPM system (a cost effective storage solution), the influence of the availability and quality of the network connection to Tier 0 via a dedicated CESNET/ESnet link and the development of light-weight yet fully automated data transfer tools allowing the movement of entire datasets from BNL (Tier 0) to Golias (Tier 2).
no_new_dataset
0.943764
1005.4270
Chriss Romy
V.Kavitha, M. Punithavalli
Clustering Time Series Data Stream - A Literature Survey
IEEE Publication format, International Journal of Computer Science and Information Security, IJCSIS, Vol. 8 No. 1, April 2010, USA. ISSN 1947 5500, http://sites.google.com/site/ijcsis/
null
null
null
cs.IR
http://creativecommons.org/licenses/by-nc-sa/3.0/
Mining Time Series data has a tremendous growth of interest in today's world. To provide an indication various implementations are studied and summarized to identify the different problems in existing applications. Clustering time series is a trouble that has applications in an extensive assortment of fields and has recently attracted a large amount of research. Time series data are frequently large and may contain outliers. In addition, time series are a special type of data set where elements have a temporal ordering. Therefore clustering of such data stream is an important issue in the data mining process. Numerous techniques and clustering algorithms have been proposed earlier to assist clustering of time series data streams. The clustering algorithms and its effectiveness on various applications are compared to develop a new method to solve the existing problem. This paper presents a survey on various clustering algorithms available for time series datasets. Moreover, the distinctiveness and restriction of previous research are discussed and several achievable topics for future study are recognized. Furthermore the areas that utilize time series clustering are also summarized.
[ { "version": "v1", "created": "Mon, 24 May 2010 07:41:29 GMT" } ]
2010-05-25T00:00:00
[ [ "Kavitha", "V.", "" ], [ "Punithavalli", "M.", "" ] ]
TITLE: Clustering Time Series Data Stream - A Literature Survey ABSTRACT: Mining Time Series data has a tremendous growth of interest in today's world. To provide an indication various implementations are studied and summarized to identify the different problems in existing applications. Clustering time series is a trouble that has applications in an extensive assortment of fields and has recently attracted a large amount of research. Time series data are frequently large and may contain outliers. In addition, time series are a special type of data set where elements have a temporal ordering. Therefore clustering of such data stream is an important issue in the data mining process. Numerous techniques and clustering algorithms have been proposed earlier to assist clustering of time series data streams. The clustering algorithms and its effectiveness on various applications are compared to develop a new method to solve the existing problem. This paper presents a survey on various clustering algorithms available for time series datasets. Moreover, the distinctiveness and restriction of previous research are discussed and several achievable topics for future study are recognized. Furthermore the areas that utilize time series clustering are also summarized.
no_new_dataset
0.951953
1005.0919
Rdv Ijcsis
Dewan Md. Farid, Mohammad Zahidur Rahman
Attribute Weighting with Adaptive NBTree for Reducing False Positives in Intrusion Detection
IEEE Publication format, International Journal of Computer Science and Information Security, IJCSIS, Vol. 8 No. 1, April 2010, USA. ISSN 1947 5500, http://sites.google.com/site/ijcsis/
null
null
null
cs.CR
http://creativecommons.org/licenses/by-nc-sa/3.0/
In this paper, we introduce new learning algorithms for reducing false positives in intrusion detection. It is based on decision tree-based attribute weighting with adaptive na\"ive Bayesian tree, which not only reduce the false positives (FP) at acceptable level, but also scale up the detection rates (DR) for different types of network intrusions. Due to the tremendous growth of network-based services, intrusion detection has emerged as an important technique for network security. Recently data mining algorithms are applied on network-based traffic data and host-based program behaviors to detect intrusions or misuse patterns, but there exist some issues in current intrusion detection algorithms such as unbalanced detection rates, large numbers of false positives, and redundant attributes that will lead to the complexity of detection model and degradation of detection accuracy. The purpose of this study is to identify important input attributes for building an intrusion detection system (IDS) that is computationally efficient and effective. Experimental results performed using the KDD99 benchmark network intrusion detection dataset indicate that the proposed approach can significantly reduce the number and percentage of false positives and scale up the balance detection rates for different types of network intrusions.
[ { "version": "v1", "created": "Thu, 6 May 2010 08:07:01 GMT" } ]
2010-05-07T00:00:00
[ [ "Farid", "Dewan Md.", "" ], [ "Rahman", "Mohammad Zahidur", "" ] ]
TITLE: Attribute Weighting with Adaptive NBTree for Reducing False Positives in Intrusion Detection ABSTRACT: In this paper, we introduce new learning algorithms for reducing false positives in intrusion detection. It is based on decision tree-based attribute weighting with adaptive na\"ive Bayesian tree, which not only reduce the false positives (FP) at acceptable level, but also scale up the detection rates (DR) for different types of network intrusions. Due to the tremendous growth of network-based services, intrusion detection has emerged as an important technique for network security. Recently data mining algorithms are applied on network-based traffic data and host-based program behaviors to detect intrusions or misuse patterns, but there exist some issues in current intrusion detection algorithms such as unbalanced detection rates, large numbers of false positives, and redundant attributes that will lead to the complexity of detection model and degradation of detection accuracy. The purpose of this study is to identify important input attributes for building an intrusion detection system (IDS) that is computationally efficient and effective. Experimental results performed using the KDD99 benchmark network intrusion detection dataset indicate that the proposed approach can significantly reduce the number and percentage of false positives and scale up the balance detection rates for different types of network intrusions.
no_new_dataset
0.947381
1005.0268
Andri Mirzal M.Sc.
Andri Mirzal and Masashi Furukawa
Node-Context Network Clustering using PARAFAC Tensor Decomposition
6 pages, 4 figures, International Conference on Information & Communication Technology and Systems
null
null
null
cs.IR
http://creativecommons.org/licenses/by-nc-sa/3.0/
We describe a clustering method for labeled link network (semantic graph) that can be used to group important nodes (highly connected nodes) with their relevant link's labels by using PARAFAC tensor decomposition. In this kind of network, the adjacency matrix can not be used to fully describe all information about the network structure. We have to expand the matrix into 3-way adjacency tensor, so that not only the information about to which nodes a node connects to but by which link's labels is also included. And by applying PARAFAC decomposition on this tensor, we get two lists, nodes and link's labels with scores attached to each node and labels, for each decomposition group. So clustering process to get the important nodes along with their relevant labels can be done simply by sorting the lists in decreasing order. To test the method, we construct labeled link network by using blog's dataset, where the blogs are the nodes and labeled links are the shared words among them. The similarity measures between the results and standard measures look promising, especially for two most important tasks, finding the most relevant words to blogs query and finding the most similar blogs to blogs query, about 0.87.
[ { "version": "v1", "created": "Mon, 3 May 2010 12:28:42 GMT" } ]
2010-05-04T00:00:00
[ [ "Mirzal", "Andri", "" ], [ "Furukawa", "Masashi", "" ] ]
TITLE: Node-Context Network Clustering using PARAFAC Tensor Decomposition ABSTRACT: We describe a clustering method for labeled link network (semantic graph) that can be used to group important nodes (highly connected nodes) with their relevant link's labels by using PARAFAC tensor decomposition. In this kind of network, the adjacency matrix can not be used to fully describe all information about the network structure. We have to expand the matrix into 3-way adjacency tensor, so that not only the information about to which nodes a node connects to but by which link's labels is also included. And by applying PARAFAC decomposition on this tensor, we get two lists, nodes and link's labels with scores attached to each node and labels, for each decomposition group. So clustering process to get the important nodes along with their relevant labels can be done simply by sorting the lists in decreasing order. To test the method, we construct labeled link network by using blog's dataset, where the blogs are the nodes and labeled links are the shared words among them. The similarity measures between the results and standard measures look promising, especially for two most important tasks, finding the most relevant words to blogs query and finding the most similar blogs to blogs query, about 0.87.
no_new_dataset
0.947039
1004.4965
Mikhail Zaslavskiy
Mikhail Zaslavskiy (CBIO), Francis Bach (INRIA Rocquencourt, LIENS), Jean-Philippe Vert (CBIO)
Many-to-Many Graph Matching: a Continuous Relaxation Approach
19
null
null
null
stat.ML cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Graphs provide an efficient tool for object representation in various computer vision applications. Once graph-based representations are constructed, an important question is how to compare graphs. This problem is often formulated as a graph matching problem where one seeks a mapping between vertices of two graphs which optimally aligns their structure. In the classical formulation of graph matching, only one-to-one correspondences between vertices are considered. However, in many applications, graphs cannot be matched perfectly and it is more interesting to consider many-to-many correspondences where clusters of vertices in one graph are matched to clusters of vertices in the other graph. In this paper, we formulate the many-to-many graph matching problem as a discrete optimization problem and propose an approximate algorithm based on a continuous relaxation of the combinatorial problem. We compare our method with other existing methods on several benchmark computer vision datasets.
[ { "version": "v1", "created": "Wed, 28 Apr 2010 07:46:55 GMT" } ]
2010-04-30T00:00:00
[ [ "Zaslavskiy", "Mikhail", "", "CBIO" ], [ "Bach", "Francis", "", "INRIA Rocquencourt, LIENS" ], [ "Vert", "Jean-Philippe", "", "CBIO" ] ]
TITLE: Many-to-Many Graph Matching: a Continuous Relaxation Approach ABSTRACT: Graphs provide an efficient tool for object representation in various computer vision applications. Once graph-based representations are constructed, an important question is how to compare graphs. This problem is often formulated as a graph matching problem where one seeks a mapping between vertices of two graphs which optimally aligns their structure. In the classical formulation of graph matching, only one-to-one correspondences between vertices are considered. However, in many applications, graphs cannot be matched perfectly and it is more interesting to consider many-to-many correspondences where clusters of vertices in one graph are matched to clusters of vertices in the other graph. In this paper, we formulate the many-to-many graph matching problem as a discrete optimization problem and propose an approximate algorithm based on a continuous relaxation of the combinatorial problem. We compare our method with other existing methods on several benchmark computer vision datasets.
no_new_dataset
0.953188
1004.5370
Dell Zhang
Dell Zhang, Jun Wang, Deng Cai, Jinsong Lu
Self-Taught Hashing for Fast Similarity Search
null
null
null
null
cs.IR
http://creativecommons.org/licenses/by/3.0/
The ability of fast similarity search at large scale is of great importance to many Information Retrieval (IR) applications. A promising way to accelerate similarity search is semantic hashing which designs compact binary codes for a large number of documents so that semantically similar documents are mapped to similar codes (within a short Hamming distance). Although some recently proposed techniques are able to generate high-quality codes for documents known in advance, obtaining the codes for previously unseen documents remains to be a very challenging problem. In this paper, we emphasise this issue and propose a novel Self-Taught Hashing (STH) approach to semantic hashing: we first find the optimal $l$-bit binary codes for all documents in the given corpus via unsupervised learning, and then train $l$ classifiers via supervised learning to predict the $l$-bit code for any query document unseen before. Our experiments on three real-world text datasets show that the proposed approach using binarised Laplacian Eigenmap (LapEig) and linear Support Vector Machine (SVM) outperforms state-of-the-art techniques significantly.
[ { "version": "v1", "created": "Thu, 29 Apr 2010 19:25:17 GMT" } ]
2010-04-30T00:00:00
[ [ "Zhang", "Dell", "" ], [ "Wang", "Jun", "" ], [ "Cai", "Deng", "" ], [ "Lu", "Jinsong", "" ] ]
TITLE: Self-Taught Hashing for Fast Similarity Search ABSTRACT: The ability of fast similarity search at large scale is of great importance to many Information Retrieval (IR) applications. A promising way to accelerate similarity search is semantic hashing which designs compact binary codes for a large number of documents so that semantically similar documents are mapped to similar codes (within a short Hamming distance). Although some recently proposed techniques are able to generate high-quality codes for documents known in advance, obtaining the codes for previously unseen documents remains to be a very challenging problem. In this paper, we emphasise this issue and propose a novel Self-Taught Hashing (STH) approach to semantic hashing: we first find the optimal $l$-bit binary codes for all documents in the given corpus via unsupervised learning, and then train $l$ classifiers via supervised learning to predict the $l$-bit code for any query document unseen before. Our experiments on three real-world text datasets show that the proposed approach using binarised Laplacian Eigenmap (LapEig) and linear Support Vector Machine (SVM) outperforms state-of-the-art techniques significantly.
no_new_dataset
0.948965
1002.3724
Francesco Silvestri
Sara Nasso (1), Francesco Silvestri (1), Francesco Tisiot (1), Barbara Di Camillo (1), Andrea Pietracaprina (1) and Gianna Maria Toffolo (1) ((1) Department of Information Engineering, University of Padova)
An Optimized Data Structure for High Throughput 3D Proteomics Data: mzRTree
Paper details: 10 pages, 7 figures, 2 tables. To be published in Journal of Proteomics. Source code available at http://www.dei.unipd.it/mzrtree
Journal of Proteomics 73(6) (2010) 1176-1182
10.1016/j.jprot.2010.02.006
null
cs.CE cs.DS q-bio.QM
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
As an emerging field, MS-based proteomics still requires software tools for efficiently storing and accessing experimental data. In this work, we focus on the management of LC-MS data, which are typically made available in standard XML-based portable formats. The structures that are currently employed to manage these data can be highly inefficient, especially when dealing with high-throughput profile data. LC-MS datasets are usually accessed through 2D range queries. Optimizing this type of operation could dramatically reduce the complexity of data analysis. We propose a novel data structure for LC-MS datasets, called mzRTree, which embodies a scalable index based on the R-tree data structure. mzRTree can be efficiently created from the XML-based data formats and it is suitable for handling very large datasets. We experimentally show that, on all range queries, mzRTree outperforms other known structures used for LC-MS data, even on those queries these structures are optimized for. Besides, mzRTree is also more space efficient. As a result, mzRTree reduces data analysis computational costs for very large profile datasets.
[ { "version": "v1", "created": "Fri, 19 Feb 2010 17:17:02 GMT" }, { "version": "v2", "created": "Mon, 22 Feb 2010 08:18:47 GMT" } ]
2010-04-27T00:00:00
[ [ "Nasso", "Sara", "" ], [ "Silvestri", "Francesco", "" ], [ "Tisiot", "Francesco", "" ], [ "Di Camillo", "Barbara", "" ], [ "Pietracaprina", "Andrea", "" ], [ "Toffolo", "Gianna Maria", "" ] ]
TITLE: An Optimized Data Structure for High Throughput 3D Proteomics Data: mzRTree ABSTRACT: As an emerging field, MS-based proteomics still requires software tools for efficiently storing and accessing experimental data. In this work, we focus on the management of LC-MS data, which are typically made available in standard XML-based portable formats. The structures that are currently employed to manage these data can be highly inefficient, especially when dealing with high-throughput profile data. LC-MS datasets are usually accessed through 2D range queries. Optimizing this type of operation could dramatically reduce the complexity of data analysis. We propose a novel data structure for LC-MS datasets, called mzRTree, which embodies a scalable index based on the R-tree data structure. mzRTree can be efficiently created from the XML-based data formats and it is suitable for handling very large datasets. We experimentally show that, on all range queries, mzRTree outperforms other known structures used for LC-MS data, even on those queries these structures are optimized for. Besides, mzRTree is also more space efficient. As a result, mzRTree reduces data analysis computational costs for very large profile datasets.
no_new_dataset
0.948298
1004.3568
Vishal Goyal
Vikram Singh, Sapna Nagpal
Integrating User's Domain Knowledge with Association Rule Mining
International Journal of Computer Science Issues online at http://ijcsi.org/articles/Integrating-Users-Domain-Knowledge-with-Association-Rule-Mining.php
IJCSI, Volume 7, Issue 2, March 2010
null
null
cs.DB cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper presents a variation of Apriori algorithm that includes the role of domain expert to guide and speed up the overall knowledge discovery task. Usually, the user is interested in finding relationships between certain attributes instead of the whole dataset. Moreover, he can help the mining algorithm to select the target database which in turn takes less time to find the desired association rules. Variants of the standard Apriori and Interactive Apriori algorithms have been run on artificial datasets. The results show that incorporating user's preference in selection of target attribute helps to search the association rules efficiently both in terms of space and time.
[ { "version": "v1", "created": "Tue, 20 Apr 2010 20:37:32 GMT" } ]
2010-04-22T00:00:00
[ [ "Singh", "Vikram", "" ], [ "Nagpal", "Sapna", "" ] ]
TITLE: Integrating User's Domain Knowledge with Association Rule Mining ABSTRACT: This paper presents a variation of Apriori algorithm that includes the role of domain expert to guide and speed up the overall knowledge discovery task. Usually, the user is interested in finding relationships between certain attributes instead of the whole dataset. Moreover, he can help the mining algorithm to select the target database which in turn takes less time to find the desired association rules. Variants of the standard Apriori and Interactive Apriori algorithms have been run on artificial datasets. The results show that incorporating user's preference in selection of target attribute helps to search the association rules efficiently both in terms of space and time.
no_new_dataset
0.949342
0906.4582
Patrick J. Wolfe
Mohamed-Ali Belabbas and Patrick J. Wolfe
On landmark selection and sampling in high-dimensional data analysis
18 pages, 6 figures, submitted for publication
Philosophical Transactions of the Royal Society, Series A, vol. 367, pp. 4295-4312, 2009
10.1098/rsta.2009.0161
null
stat.ML cs.CV cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In recent years, the spectral analysis of appropriately defined kernel matrices has emerged as a principled way to extract the low-dimensional structure often prevalent in high-dimensional data. Here we provide an introduction to spectral methods for linear and nonlinear dimension reduction, emphasizing ways to overcome the computational limitations currently faced by practitioners with massive datasets. In particular, a data subsampling or landmark selection process is often employed to construct a kernel based on partial information, followed by an approximate spectral analysis termed the Nystrom extension. We provide a quantitative framework to analyse this procedure, and use it to demonstrate algorithmic performance bounds on a range of practical approaches designed to optimize the landmark selection process. We compare the practical implications of these bounds by way of real-world examples drawn from the field of computer vision, whereby low-dimensional manifold structure is shown to emerge from high-dimensional video data streams.
[ { "version": "v1", "created": "Wed, 24 Jun 2009 23:40:22 GMT" } ]
2010-04-20T00:00:00
[ [ "Belabbas", "Mohamed-Ali", "" ], [ "Wolfe", "Patrick J.", "" ] ]
TITLE: On landmark selection and sampling in high-dimensional data analysis ABSTRACT: In recent years, the spectral analysis of appropriately defined kernel matrices has emerged as a principled way to extract the low-dimensional structure often prevalent in high-dimensional data. Here we provide an introduction to spectral methods for linear and nonlinear dimension reduction, emphasizing ways to overcome the computational limitations currently faced by practitioners with massive datasets. In particular, a data subsampling or landmark selection process is often employed to construct a kernel based on partial information, followed by an approximate spectral analysis termed the Nystrom extension. We provide a quantitative framework to analyse this procedure, and use it to demonstrate algorithmic performance bounds on a range of practical approaches designed to optimize the landmark selection process. We compare the practical implications of these bounds by way of real-world examples drawn from the field of computer vision, whereby low-dimensional manifold structure is shown to emerge from high-dimensional video data streams.
no_new_dataset
0.951006
1004.3175
Eva Kranz
Eva Kranz
Structural Stability and Immunogenicity of Peptides
null
null
null
null
q-bio.BM cs.CG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigated the role of peptide folding stability in peptide immunogenicity. It was the aim of this thesis to implement a stability criterion based on energy computations using an AMBER force field, and to test the implementation with a large dataset.
[ { "version": "v1", "created": "Mon, 19 Apr 2010 12:43:55 GMT" } ]
2010-04-20T00:00:00
[ [ "Kranz", "Eva", "" ] ]
TITLE: Structural Stability and Immunogenicity of Peptides ABSTRACT: We investigated the role of peptide folding stability in peptide immunogenicity. It was the aim of this thesis to implement a stability criterion based on energy computations using an AMBER force field, and to test the implementation with a large dataset.
no_new_dataset
0.948728
1004.2447
Jeremy Faden Mr.
J. Faden, R. S. Weigel, J. Merka, R. H. W. Friedel
Autoplot: A browser for scientific data on the web
16 pages
null
10.1007/s12145-010-0049-0
null
cs.GR physics.data-an physics.space-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Autoplot is software developed for the Virtual Observatories in Heliophysics to provide intelligent and automated plotting capabilities for many typical data products that are stored in a variety of file formats or databases. Autoplot has proven to be a flexible tool for exploring, accessing, and viewing data resources as typically found on the web, usually in the form of a directory containing data files with multiple parameters contained in each file. Data from a data source is abstracted into a common internal data model called QDataSet. Autoplot is built from individually useful components, and can be extended and reused to create specialized data handling and analysis applications and is being used in a variety of science visualization and analysis applications. Although originally developed for viewing heliophysics-related time series and spectrograms, its flexible and generic data representation model makes it potentially useful for the Earth sciences.
[ { "version": "v1", "created": "Wed, 14 Apr 2010 16:40:41 GMT" } ]
2010-04-15T00:00:00
[ [ "Faden", "J.", "" ], [ "Weigel", "R. S.", "" ], [ "Merka", "J.", "" ], [ "Friedel", "R. H. W.", "" ] ]
TITLE: Autoplot: A browser for scientific data on the web ABSTRACT: Autoplot is software developed for the Virtual Observatories in Heliophysics to provide intelligent and automated plotting capabilities for many typical data products that are stored in a variety of file formats or databases. Autoplot has proven to be a flexible tool for exploring, accessing, and viewing data resources as typically found on the web, usually in the form of a directory containing data files with multiple parameters contained in each file. Data from a data source is abstracted into a common internal data model called QDataSet. Autoplot is built from individually useful components, and can be extended and reused to create specialized data handling and analysis applications and is being used in a variety of science visualization and analysis applications. Although originally developed for viewing heliophysics-related time series and spectrograms, its flexible and generic data representation model makes it potentially useful for the Earth sciences.
no_new_dataset
0.940353
1004.1743
Rdv Ijcsis
G. Nathiya, S. C. Punitha, M. Punithavalli
An Analytical Study on Behavior of Clusters Using K Means, EM and K* Means Algorithm
IEEE Publication format, ISSN 1947 5500, http://sites.google.com/site/ijcsis/
IJCSIS, Vol. 7 No. 3, March 2010, 185-190
null
null
cs.LG cs.IR
http://creativecommons.org/licenses/by-nc-sa/3.0/
Clustering is an unsupervised learning method that constitutes a cornerstone of an intelligent data analysis process. It is used for the exploration of inter-relationships among a collection of patterns, by organizing them into homogeneous clusters. Clustering has been dynamically applied to a variety of tasks in the field of Information Retrieval (IR). Clustering has become one of the most active area of research and the development. Clustering attempts to discover the set of consequential groups where those within each group are more closely related to one another than the others assigned to different groups. The resultant clusters can provide a structure for organizing large bodies of text for efficient browsing and searching. There exists a wide variety of clustering algorithms that has been intensively studied in the clustering problem. Among the algorithms that remain the most common and effectual, the iterative optimization clustering algorithms have been demonstrated reasonable performance for clustering, e.g. the Expectation Maximization (EM) algorithm and its variants, and the well known k-means algorithm. This paper presents an analysis on how partition method clustering techniques - EM, K -means and K* Means algorithm work on heartspect dataset with below mentioned features - Purity, Entropy, CPU time, Cluster wise analysis, Mean value analysis and inter cluster distance. Thus the paper finally provides the experimental results of datasets for five clusters to strengthen the results that the quality of the behavior in clusters in EM algorithm is far better than k-means algorithm and k*means algorithm.
[ { "version": "v1", "created": "Sat, 10 Apr 2010 21:58:16 GMT" } ]
2010-04-13T00:00:00
[ [ "Nathiya", "G.", "" ], [ "Punitha", "S. C.", "" ], [ "Punithavalli", "M.", "" ] ]
TITLE: An Analytical Study on Behavior of Clusters Using K Means, EM and K* Means Algorithm ABSTRACT: Clustering is an unsupervised learning method that constitutes a cornerstone of an intelligent data analysis process. It is used for the exploration of inter-relationships among a collection of patterns, by organizing them into homogeneous clusters. Clustering has been dynamically applied to a variety of tasks in the field of Information Retrieval (IR). Clustering has become one of the most active area of research and the development. Clustering attempts to discover the set of consequential groups where those within each group are more closely related to one another than the others assigned to different groups. The resultant clusters can provide a structure for organizing large bodies of text for efficient browsing and searching. There exists a wide variety of clustering algorithms that has been intensively studied in the clustering problem. Among the algorithms that remain the most common and effectual, the iterative optimization clustering algorithms have been demonstrated reasonable performance for clustering, e.g. the Expectation Maximization (EM) algorithm and its variants, and the well known k-means algorithm. This paper presents an analysis on how partition method clustering techniques - EM, K -means and K* Means algorithm work on heartspect dataset with below mentioned features - Purity, Entropy, CPU time, Cluster wise analysis, Mean value analysis and inter cluster distance. Thus the paper finally provides the experimental results of datasets for five clusters to strengthen the results that the quality of the behavior in clusters in EM algorithm is far better than k-means algorithm and k*means algorithm.
no_new_dataset
0.950686
1004.1982
Dar\'io Garc\'ia-Garc\'ia
Dar\'io Garc\'ia-Garc\'ia and Emilio Parrado-Hern\'andez and Fernando D\'iaz-de-Mar\'ia
State-Space Dynamics Distance for Clustering Sequential Data
null
null
null
null
cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper proposes a novel similarity measure for clustering sequential data. We first construct a common state-space by training a single probabilistic model with all the sequences in order to get a unified representation for the dataset. Then, distances are obtained attending to the transition matrices induced by each sequence in that state-space. This approach solves some of the usual overfitting and scalability issues of the existing semi-parametric techniques, that rely on training a model for each sequence. Empirical studies on both synthetic and real-world datasets illustrate the advantages of the proposed similarity measure for clustering sequences.
[ { "version": "v1", "created": "Fri, 9 Apr 2010 09:36:28 GMT" } ]
2010-04-13T00:00:00
[ [ "García-García", "Darío", "" ], [ "Parrado-Hernández", "Emilio", "" ], [ "Díaz-de-María", "Fernando", "" ] ]
TITLE: State-Space Dynamics Distance for Clustering Sequential Data ABSTRACT: This paper proposes a novel similarity measure for clustering sequential data. We first construct a common state-space by training a single probabilistic model with all the sequences in order to get a unified representation for the dataset. Then, distances are obtained attending to the transition matrices induced by each sequence in that state-space. This approach solves some of the usual overfitting and scalability issues of the existing semi-parametric techniques, that rely on training a model for each sequence. Empirical studies on both synthetic and real-world datasets illustrate the advantages of the proposed similarity measure for clustering sequences.
no_new_dataset
0.950641
1002.1587
Valiya Hamza M
V. M. Hamza, R. R. Cardoso, C. H. Alexandrino
A Magma Accretion Model for the Formation of Oceanic Lithosphere: Implications for Global Heat Loss
45 pages, 11 figures
null
null
null
physics.geo-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A simple magma accretion model of the oceanic lithosphere is proposed and its implications for understanding the thermal field of oceanic lithosphere examined. The new model (designated VBA) assumes existence of lateral variations in magma accretion rates and temperatures at the boundary zone between the lithosphere and the asthenosphere. Heat flow and bathymetry variations calculated on the basis of the VBA model provide vastly improved fits to respective observational datasets. The improved fits have been achieved for the entire age range and without the need to invoke the ad-hoc hypothesis of large-scale hydrothermal circulation in stable ocean crust. The results suggest that estimates of global heat loss need to be downsized by at least 25%.
[ { "version": "v1", "created": "Mon, 8 Feb 2010 12:25:20 GMT" }, { "version": "v2", "created": "Wed, 7 Apr 2010 10:39:10 GMT" } ]
2010-04-08T00:00:00
[ [ "Hamza", "V. M.", "" ], [ "Cardoso", "R. R.", "" ], [ "Alexandrino", "C. H.", "" ] ]
TITLE: A Magma Accretion Model for the Formation of Oceanic Lithosphere: Implications for Global Heat Loss ABSTRACT: A simple magma accretion model of the oceanic lithosphere is proposed and its implications for understanding the thermal field of oceanic lithosphere examined. The new model (designated VBA) assumes existence of lateral variations in magma accretion rates and temperatures at the boundary zone between the lithosphere and the asthenosphere. Heat flow and bathymetry variations calculated on the basis of the VBA model provide vastly improved fits to respective observational datasets. The improved fits have been achieved for the entire age range and without the need to invoke the ad-hoc hypothesis of large-scale hydrothermal circulation in stable ocean crust. The results suggest that estimates of global heat loss need to be downsized by at least 25%.
no_new_dataset
0.952706
1004.0456
Fabrice Rossi
Georges H\'ebrail and Bernard Hugueney and Yves Lechevallier and Fabrice Rossi
Exploratory Analysis of Functional Data via Clustering and Optimal Segmentation
null
Neurocomputing, Volume 73, Issues 7-9, March 2010, Pages 1125-1141
10.1016/j.neucom.2009.11.022
null
stat.ML cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose in this paper an exploratory analysis algorithm for functional data. The method partitions a set of functions into $K$ clusters and represents each cluster by a simple prototype (e.g., piecewise constant). The total number of segments in the prototypes, $P$, is chosen by the user and optimally distributed among the clusters via two dynamic programming algorithms. The practical relevance of the method is shown on two real world datasets.
[ { "version": "v1", "created": "Sat, 3 Apr 2010 16:28:47 GMT" } ]
2010-04-06T00:00:00
[ [ "Hébrail", "Georges", "" ], [ "Hugueney", "Bernard", "" ], [ "Lechevallier", "Yves", "" ], [ "Rossi", "Fabrice", "" ] ]
TITLE: Exploratory Analysis of Functional Data via Clustering and Optimal Segmentation ABSTRACT: We propose in this paper an exploratory analysis algorithm for functional data. The method partitions a set of functions into $K$ clusters and represents each cluster by a simple prototype (e.g., piecewise constant). The total number of segments in the prototypes, $P$, is chosen by the user and optimally distributed among the clusters via two dynamic programming algorithms. The practical relevance of the method is shown on two real world datasets.
no_new_dataset
0.948632
1003.5886
Sandip Rakshit
Sandip Rakshit, Subhadip Basu
Development of a multi-user handwriting recognition system using Tesseract open source OCR engine
Proc. International Conference on C3IT (2009) 240-247
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The objective of the paper is to recognize handwritten samples of lower case Roman script using Tesseract open source Optical Character Recognition (OCR) engine under Apache License 2.0. Handwritten data samples containing isolated and free-flow text were collected from different users. Tesseract is trained with user-specific data samples of both the categories of document pages to generate separate user-models representing a unique language-set. Each such language-set recognizes isolated and free-flow handwritten test samples collected from the designated user. On a three user model, the system is trained with 1844, 1535 and 1113 isolated handwritten character samples collected from three different users and the performance is tested on 1133, 1186 and 1204 character samples, collected form the test sets of the three users respectively. The user specific character level accuracies were obtained as 87.92%, 81.53% and 65.71% respectively. The overall character-level accuracy of the system is observed as 78.39%. The system fails to segment 10.96% characters and erroneously classifies 10.65% characters on the overall dataset.
[ { "version": "v1", "created": "Tue, 30 Mar 2010 18:22:44 GMT" } ]
2010-03-31T00:00:00
[ [ "Rakshit", "Sandip", "" ], [ "Basu", "Subhadip", "" ] ]
TITLE: Development of a multi-user handwriting recognition system using Tesseract open source OCR engine ABSTRACT: The objective of the paper is to recognize handwritten samples of lower case Roman script using Tesseract open source Optical Character Recognition (OCR) engine under Apache License 2.0. Handwritten data samples containing isolated and free-flow text were collected from different users. Tesseract is trained with user-specific data samples of both the categories of document pages to generate separate user-models representing a unique language-set. Each such language-set recognizes isolated and free-flow handwritten test samples collected from the designated user. On a three user model, the system is trained with 1844, 1535 and 1113 isolated handwritten character samples collected from three different users and the performance is tested on 1133, 1186 and 1204 character samples, collected form the test sets of the three users respectively. The user specific character level accuracies were obtained as 87.92%, 81.53% and 65.71% respectively. The overall character-level accuracy of the system is observed as 78.39%. The system fails to segment 10.96% characters and erroneously classifies 10.65% characters on the overall dataset.
no_new_dataset
0.943815
1003.5897
Sandip Rakshit
Sandip Rakshit, Debkumar Ghosal, Tanmoy Das, Subhrajit Dutta, Subhadip Basu
Development of a Multi-User Recognition Engine for Handwritten Bangla Basic Characters and Digits
Proc. (CD) Int. Conf. on Information Technology and Business Intelligence (2009)
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The objective of the paper is to recognize handwritten samples of basic Bangla characters using Tesseract open source Optical Character Recognition (OCR) engine under Apache License 2.0. Handwritten data samples containing isolated Bangla basic characters and digits were collected from different users. Tesseract is trained with user-specific data samples of document pages to generate separate user-models representing a unique language-set. Each such language-set recognizes isolated basic Bangla handwritten test samples collected from the designated users. On a three user model, the system is trained with 919, 928 and 648 isolated handwritten character and digit samples and the performance is tested on 1527, 14116 and 1279 character and digit samples, collected form the test datasets of the three users respectively. The user specific character/digit recognition accuracies were obtained as 90.66%, 91.66% and 96.87% respectively. The overall basic character-level and digit level accuracy of the system is observed as 92.15% and 97.37%. The system fails to segment 12.33% characters and 15.96% digits and also erroneously classifies 7.85% characters and 2.63% on the overall dataset.
[ { "version": "v1", "created": "Tue, 30 Mar 2010 18:54:57 GMT" } ]
2010-03-31T00:00:00
[ [ "Rakshit", "Sandip", "" ], [ "Ghosal", "Debkumar", "" ], [ "Das", "Tanmoy", "" ], [ "Dutta", "Subhrajit", "" ], [ "Basu", "Subhadip", "" ] ]
TITLE: Development of a Multi-User Recognition Engine for Handwritten Bangla Basic Characters and Digits ABSTRACT: The objective of the paper is to recognize handwritten samples of basic Bangla characters using Tesseract open source Optical Character Recognition (OCR) engine under Apache License 2.0. Handwritten data samples containing isolated Bangla basic characters and digits were collected from different users. Tesseract is trained with user-specific data samples of document pages to generate separate user-models representing a unique language-set. Each such language-set recognizes isolated basic Bangla handwritten test samples collected from the designated users. On a three user model, the system is trained with 919, 928 and 648 isolated handwritten character and digit samples and the performance is tested on 1527, 14116 and 1279 character and digit samples, collected form the test datasets of the three users respectively. The user specific character/digit recognition accuracies were obtained as 90.66%, 91.66% and 96.87% respectively. The overall basic character-level and digit level accuracy of the system is observed as 92.15% and 97.37%. The system fails to segment 12.33% characters and 15.96% digits and also erroneously classifies 7.85% characters and 2.63% on the overall dataset.
no_new_dataset
0.934813
1003.5898
Sandip Rakshit
Sandip Rakshit, Amitava Kundu, Mrinmoy Maity, Subhajit Mandal, Satwika Sarkar, Subhadip Basu
Recognition of handwritten Roman Numerals using Tesseract open source OCR engine
Proc. Int. Conf. on Advances in Computer Vision and Information Technology (2009) 572-577
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The objective of the paper is to recognize handwritten samples of Roman numerals using Tesseract open source Optical Character Recognition (OCR) engine. Tesseract is trained with data samples of different persons to generate one user-independent language model, representing the handwritten Roman digit-set. The system is trained with 1226 digit samples collected form the different users. The performance is tested on two different datasets, one consisting of samples collected from the known users (those who prepared the training data samples) and the other consisting of handwritten data samples of unknown users. The overall recognition accuracy is obtained as 92.1% and 86.59% on these test datasets respectively.
[ { "version": "v1", "created": "Tue, 30 Mar 2010 18:59:49 GMT" } ]
2010-03-31T00:00:00
[ [ "Rakshit", "Sandip", "" ], [ "Kundu", "Amitava", "" ], [ "Maity", "Mrinmoy", "" ], [ "Mandal", "Subhajit", "" ], [ "Sarkar", "Satwika", "" ], [ "Basu", "Subhadip", "" ] ]
TITLE: Recognition of handwritten Roman Numerals using Tesseract open source OCR engine ABSTRACT: The objective of the paper is to recognize handwritten samples of Roman numerals using Tesseract open source Optical Character Recognition (OCR) engine. Tesseract is trained with data samples of different persons to generate one user-independent language model, representing the handwritten Roman digit-set. The system is trained with 1226 digit samples collected form the different users. The performance is tested on two different datasets, one consisting of samples collected from the known users (those who prepared the training data samples) and the other consisting of handwritten data samples of unknown users. The overall recognition accuracy is obtained as 92.1% and 86.59% on these test datasets respectively.
no_new_dataset
0.953101
1002.4007
William Jackson
Ram Sarkar, Nibaran Das, Subhadip Basu, Mahantapas Kundu, Mita Nasipuri, Dipak Kumar Basu
Word level Script Identification from Bangla and Devanagri Handwritten Texts mixed with Roman Script
null
Journal of Computing, Volume 2, Issue 2, February 2010, https://sites.google.com/site/journalofcomputing/
null
null
cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
India is a multi-lingual country where Roman script is often used alongside different Indic scripts in a text document. To develop a script specific handwritten Optical Character Recognition (OCR) system, it is therefore necessary to identify the scripts of handwritten text correctly. In this paper, we present a system, which automatically separates the scripts of handwritten words from a document, written in Bangla or Devanagri mixed with Roman scripts. In this script separation technique, we first, extract the text lines and words from document pages using a script independent Neighboring Component Analysis technique. Then we have designed a Multi Layer Perceptron (MLP) based classifier for script separation, trained with 8 different wordlevel holistic features. Two equal sized datasets, one with Bangla and Roman scripts and the other with Devanagri and Roman scripts, are prepared for the system evaluation. On respective independent text samples, word-level script identification accuracies of 99.29% and 98.43% are achieved.
[ { "version": "v1", "created": "Sun, 21 Feb 2010 19:48:16 GMT" } ]
2010-03-25T00:00:00
[ [ "Sarkar", "Ram", "" ], [ "Das", "Nibaran", "" ], [ "Basu", "Subhadip", "" ], [ "Kundu", "Mahantapas", "" ], [ "Nasipuri", "Mita", "" ], [ "Basu", "Dipak Kumar", "" ] ]
TITLE: Word level Script Identification from Bangla and Devanagri Handwritten Texts mixed with Roman Script ABSTRACT: India is a multi-lingual country where Roman script is often used alongside different Indic scripts in a text document. To develop a script specific handwritten Optical Character Recognition (OCR) system, it is therefore necessary to identify the scripts of handwritten text correctly. In this paper, we present a system, which automatically separates the scripts of handwritten words from a document, written in Bangla or Devanagri mixed with Roman scripts. In this script separation technique, we first, extract the text lines and words from document pages using a script independent Neighboring Component Analysis technique. Then we have designed a Multi Layer Perceptron (MLP) based classifier for script separation, trained with 8 different wordlevel holistic features. Two equal sized datasets, one with Bangla and Roman scripts and the other with Devanagri and Roman scripts, are prepared for the system evaluation. On respective independent text samples, word-level script identification accuracies of 99.29% and 98.43% are achieved.
no_new_dataset
0.918991
1002.4048
William Jackson
Satadal Saha, Subhadip Basu, Mita Nasipuri, Dipak Kr. Basu
A Hough Transform based Technique for Text Segmentation
null
Journal of Computing, Volume 2, Issue 2, February 2010, https://sites.google.com/site/journalofcomputing/
null
null
cs.IR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Text segmentation is an inherent part of an OCR system irrespective of the domain of application of it. The OCR system contains a segmentation module where the text lines, words and ultimately the characters must be segmented properly for its successful recognition. The present work implements a Hough transform based technique for line and word segmentation from digitized images. The proposed technique is applied not only on the document image dataset but also on dataset for business card reader system and license plate recognition system. For standardization of the performance of the system the technique is also applied on public domain dataset published in the website by CMATER, Jadavpur University. The document images consist of multi-script printed and hand written text lines with variety in script and line spacing in single document image. The technique performs quite satisfactorily when applied on mobile camera captured business card images with low resolution. The usefulness of the technique is verified by applying it in a commercial project for localization of license plate of vehicles from surveillance camera images by the process of segmentation itself. The accuracy of the technique for word segmentation, as verified experimentally, is 85.7% for document images, 94.6% for business card images and 88% for surveillance camera images.
[ { "version": "v1", "created": "Mon, 22 Feb 2010 03:16:55 GMT" } ]
2010-03-23T00:00:00
[ [ "Saha", "Satadal", "" ], [ "Basu", "Subhadip", "" ], [ "Nasipuri", "Mita", "" ], [ "Basu", "Dipak Kr.", "" ] ]
TITLE: A Hough Transform based Technique for Text Segmentation ABSTRACT: Text segmentation is an inherent part of an OCR system irrespective of the domain of application of it. The OCR system contains a segmentation module where the text lines, words and ultimately the characters must be segmented properly for its successful recognition. The present work implements a Hough transform based technique for line and word segmentation from digitized images. The proposed technique is applied not only on the document image dataset but also on dataset for business card reader system and license plate recognition system. For standardization of the performance of the system the technique is also applied on public domain dataset published in the website by CMATER, Jadavpur University. The document images consist of multi-script printed and hand written text lines with variety in script and line spacing in single document image. The technique performs quite satisfactorily when applied on mobile camera captured business card images with low resolution. The usefulness of the technique is verified by applying it in a commercial project for localization of license plate of vehicles from surveillance camera images by the process of segmentation itself. The accuracy of the technique for word segmentation, as verified experimentally, is 85.7% for document images, 94.6% for business card images and 88% for surveillance camera images.
no_new_dataset
0.954265
0812.5064
Qiang Li
Qiang Li, Zhuo Chen, Yan He, Jing-ping Jiang
A Novel Clustering Algorithm Based Upon Games on Evolving Network
17 pages, 5 figures, 3 tables
Expert Systems with Applications, 2010
10.1016/j.eswa.2010.02.050
null
cs.LG cs.CV cs.GT nlin.AO
http://creativecommons.org/licenses/by-nc-sa/3.0/
This paper introduces a model based upon games on an evolving network, and develops three clustering algorithms according to it. In the clustering algorithms, data points for clustering are regarded as players who can make decisions in games. On the network describing relationships among data points, an edge-removing-and-rewiring (ERR) function is employed to explore in a neighborhood of a data point, which removes edges connecting to neighbors with small payoffs, and creates new edges to neighbors with larger payoffs. As such, the connections among data points vary over time. During the evolution of network, some strategies are spread in the network. As a consequence, clusters are formed automatically, in which data points with the same evolutionarily stable strategy are collected as a cluster, so the number of evolutionarily stable strategies indicates the number of clusters. Moreover, the experimental results have demonstrated that data points in datasets are clustered reasonably and efficiently, and the comparison with other algorithms also provides an indication of the effectiveness of the proposed algorithms.
[ { "version": "v1", "created": "Tue, 30 Dec 2008 13:22:31 GMT" }, { "version": "v2", "created": "Fri, 19 Mar 2010 13:30:08 GMT" } ]
2010-03-22T00:00:00
[ [ "Li", "Qiang", "" ], [ "Chen", "Zhuo", "" ], [ "He", "Yan", "" ], [ "Jiang", "Jing-ping", "" ] ]
TITLE: A Novel Clustering Algorithm Based Upon Games on Evolving Network ABSTRACT: This paper introduces a model based upon games on an evolving network, and develops three clustering algorithms according to it. In the clustering algorithms, data points for clustering are regarded as players who can make decisions in games. On the network describing relationships among data points, an edge-removing-and-rewiring (ERR) function is employed to explore in a neighborhood of a data point, which removes edges connecting to neighbors with small payoffs, and creates new edges to neighbors with larger payoffs. As such, the connections among data points vary over time. During the evolution of network, some strategies are spread in the network. As a consequence, clusters are formed automatically, in which data points with the same evolutionarily stable strategy are collected as a cluster, so the number of evolutionarily stable strategies indicates the number of clusters. Moreover, the experimental results have demonstrated that data points in datasets are clustered reasonably and efficiently, and the comparison with other algorithms also provides an indication of the effectiveness of the proposed algorithms.
no_new_dataset
0.956553
1003.2424
Jure Leskovec
Jure Leskovec, Daniel Huttenlocher, Jon Kleinberg
Signed Networks in Social Media
null
CHI 2010: 28th ACM Conference on Human Factors in Computing Systems
null
null
physics.soc-ph cs.CY cs.HC
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Relations between users on social media sites often reflect a mixture of positive (friendly) and negative (antagonistic) interactions. In contrast to the bulk of research on social networks that has focused almost exclusively on positive interpretations of links between people, we study how the interplay between positive and negative relationships affects the structure of on-line social networks. We connect our analyses to theories of signed networks from social psychology. We find that the classical theory of structural balance tends to capture certain common patterns of interaction, but that it is also at odds with some of the fundamental phenomena we observe --- particularly related to the evolving, directed nature of these on-line networks. We then develop an alternate theory of status that better explains the observed edge signs and provides insights into the underlying social mechanisms. Our work provides one of the first large-scale evaluations of theories of signed networks using on-line datasets, as well as providing a perspective for reasoning about social media sites.
[ { "version": "v1", "created": "Thu, 11 Mar 2010 21:11:26 GMT" } ]
2010-03-15T00:00:00
[ [ "Leskovec", "Jure", "" ], [ "Huttenlocher", "Daniel", "" ], [ "Kleinberg", "Jon", "" ] ]
TITLE: Signed Networks in Social Media ABSTRACT: Relations between users on social media sites often reflect a mixture of positive (friendly) and negative (antagonistic) interactions. In contrast to the bulk of research on social networks that has focused almost exclusively on positive interpretations of links between people, we study how the interplay between positive and negative relationships affects the structure of on-line social networks. We connect our analyses to theories of signed networks from social psychology. We find that the classical theory of structural balance tends to capture certain common patterns of interaction, but that it is also at odds with some of the fundamental phenomena we observe --- particularly related to the evolving, directed nature of these on-line networks. We then develop an alternate theory of status that better explains the observed edge signs and provides insights into the underlying social mechanisms. Our work provides one of the first large-scale evaluations of theories of signed networks using on-line datasets, as well as providing a perspective for reasoning about social media sites.
no_new_dataset
0.948965
1003.2429
Jure Leskovec
Jure Leskovec, Daniel Huttenlocher, Jon Kleinberg
Predicting Positive and Negative Links in Online Social Networks
null
WWW 2010: ACM WWW International conference on World Wide Web, 2010
null
null
physics.soc-ph cs.AI cs.CY
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study online social networks in which relationships can be either positive (indicating relations such as friendship) or negative (indicating relations such as opposition or antagonism). Such a mix of positive and negative links arise in a variety of online settings; we study datasets from Epinions, Slashdot and Wikipedia. We find that the signs of links in the underlying social networks can be predicted with high accuracy, using models that generalize across this diverse range of sites. These models provide insight into some of the fundamental principles that drive the formation of signed links in networks, shedding light on theories of balance and status from social psychology; they also suggest social computing applications by which the attitude of one user toward another can be estimated from evidence provided by their relationships with other members of the surrounding social network.
[ { "version": "v1", "created": "Thu, 11 Mar 2010 21:27:11 GMT" } ]
2010-03-15T00:00:00
[ [ "Leskovec", "Jure", "" ], [ "Huttenlocher", "Daniel", "" ], [ "Kleinberg", "Jon", "" ] ]
TITLE: Predicting Positive and Negative Links in Online Social Networks ABSTRACT: We study online social networks in which relationships can be either positive (indicating relations such as friendship) or negative (indicating relations such as opposition or antagonism). Such a mix of positive and negative links arise in a variety of online settings; we study datasets from Epinions, Slashdot and Wikipedia. We find that the signs of links in the underlying social networks can be predicted with high accuracy, using models that generalize across this diverse range of sites. These models provide insight into some of the fundamental principles that drive the formation of signed links in networks, shedding light on theories of balance and status from social psychology; they also suggest social computing applications by which the attitude of one user toward another can be estimated from evidence provided by their relationships with other members of the surrounding social network.
no_new_dataset
0.944485
0909.3472
J\'er\^oAme Kunegis
J\'er\^ome Kunegis, Alan Said, Winfried Umbrath
The Universal Recommender
17 pages; typo and references fixed
null
null
null
cs.IR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We describe the Universal Recommender, a recommender system for semantic datasets that generalizes domain-specific recommenders such as content-based, collaborative, social, bibliographic, lexicographic, hybrid and other recommenders. In contrast to existing recommender systems, the Universal Recommender applies to any dataset that allows a semantic representation. We describe the scalable three-stage architecture of the Universal Recommender and its application to Internet Protocol Television (IPTV). To achieve good recommendation accuracy, several novel machine learning and optimization problems are identified. We finally give a brief argument supporting the need for machine learning recommenders.
[ { "version": "v1", "created": "Fri, 18 Sep 2009 15:54:51 GMT" }, { "version": "v2", "created": "Tue, 9 Mar 2010 12:43:28 GMT" } ]
2010-03-13T00:00:00
[ [ "Kunegis", "Jérôme", "" ], [ "Said", "Alan", "" ], [ "Umbrath", "Winfried", "" ] ]
TITLE: The Universal Recommender ABSTRACT: We describe the Universal Recommender, a recommender system for semantic datasets that generalizes domain-specific recommenders such as content-based, collaborative, social, bibliographic, lexicographic, hybrid and other recommenders. In contrast to existing recommender systems, the Universal Recommender applies to any dataset that allows a semantic representation. We describe the scalable three-stage architecture of the Universal Recommender and its application to Internet Protocol Television (IPTV). To achieve good recommendation accuracy, several novel machine learning and optimization problems are identified. We finally give a brief argument supporting the need for machine learning recommenders.
no_new_dataset
0.948917
1003.1814
Rdv Ijcsis
Alok Ranjan, Harish Verma, Eatesh Kandpal, Joydip Dhar
An Analytical Approach to Document Clustering Based on Internal Criterion Function
Pages IEEE format, International Journal of Computer Science and Information Security, IJCSIS, Vol. 7 No. 2, February 2010, USA. ISSN 1947 5500, http://sites.google.com/site/ijcsis/
null
null
null
cs.IR
http://creativecommons.org/licenses/by-nc-sa/3.0/
Fast and high quality document clustering is an important task in organizing information, search engine results obtaining from user query, enhancing web crawling and information retrieval. With the large amount of data available and with a goal of creating good quality clusters, a variety of algorithms have been developed having quality-complexity trade-offs. Among these, some algorithms seek to minimize the computational complexity using certain criterion functions which are defined for the whole set of clustering solution. In this paper, we are proposing a novel document clustering algorithm based on an internal criterion function. Most commonly used partitioning clustering algorithms (e.g. k-means) have some drawbacks as they suffer from local optimum solutions and creation of empty clusters as a clustering solution. The proposed algorithm usually does not suffer from these problems and converge to a global optimum, its performance enhances with the increase in number of clusters. We have checked our algorithm against three different datasets for four different values of k (required number of clusters).
[ { "version": "v1", "created": "Tue, 9 Mar 2010 07:28:07 GMT" } ]
2010-03-11T00:00:00
[ [ "Ranjan", "Alok", "" ], [ "Verma", "Harish", "" ], [ "Kandpal", "Eatesh", "" ], [ "Dhar", "Joydip", "" ] ]
TITLE: An Analytical Approach to Document Clustering Based on Internal Criterion Function ABSTRACT: Fast and high quality document clustering is an important task in organizing information, search engine results obtaining from user query, enhancing web crawling and information retrieval. With the large amount of data available and with a goal of creating good quality clusters, a variety of algorithms have been developed having quality-complexity trade-offs. Among these, some algorithms seek to minimize the computational complexity using certain criterion functions which are defined for the whole set of clustering solution. In this paper, we are proposing a novel document clustering algorithm based on an internal criterion function. Most commonly used partitioning clustering algorithms (e.g. k-means) have some drawbacks as they suffer from local optimum solutions and creation of empty clusters as a clustering solution. The proposed algorithm usually does not suffer from these problems and converge to a global optimum, its performance enhances with the increase in number of clusters. We have checked our algorithm against three different datasets for four different values of k (required number of clusters).
no_new_dataset
0.949248
1003.1795
Rdv Ijcsis
Vidhya. K. A, G. Aghila
A Survey of Na\"ive Bayes Machine Learning approach in Text Document Classification
Pages IEEE format, International Journal of Computer Science and Information Security, IJCSIS, Vol. 7 No. 2, February 2010, USA. ISSN 1947 5500, http://sites.google.com/site/ijcsis/
null
null
null
cs.LG cs.IR
http://creativecommons.org/licenses/by-nc-sa/3.0/
Text Document classification aims in associating one or more predefined categories based on the likelihood suggested by the training set of labeled documents. Many machine learning algorithms play a vital role in training the system with predefined categories among which Na\"ive Bayes has some intriguing facts that it is simple, easy to implement and draws better accuracy in large datasets in spite of the na\"ive dependence. The importance of Na\"ive Bayes Machine learning approach has felt hence the study has been taken up for text document classification and the statistical event models available. This survey the various feature selection methods has been discussed and compared along with the metrics related to text document classification.
[ { "version": "v1", "created": "Tue, 9 Mar 2010 06:41:49 GMT" } ]
2010-03-10T00:00:00
[ [ "A", "Vidhya. K.", "" ], [ "Aghila", "G.", "" ] ]
TITLE: A Survey of Na\"ive Bayes Machine Learning approach in Text Document Classification ABSTRACT: Text Document classification aims in associating one or more predefined categories based on the likelihood suggested by the training set of labeled documents. Many machine learning algorithms play a vital role in training the system with predefined categories among which Na\"ive Bayes has some intriguing facts that it is simple, easy to implement and draws better accuracy in large datasets in spite of the na\"ive dependence. The importance of Na\"ive Bayes Machine learning approach has felt hence the study has been taken up for text document classification and the statistical event models available. This survey the various feature selection methods has been discussed and compared along with the metrics related to text document classification.
no_new_dataset
0.948489
0906.3585
Arnab Bhattacharya
Vishwakarma Singh, Arnab Bhattacharya, Ambuj K. Singh
Finding Significant Subregions in Large Image Databases
16 pages, 48 figures
Extending Database Technology (EDBT) 2010
null
null
cs.DB cs.CV cs.IR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Images have become an important data source in many scientific and commercial domains. Analysis and exploration of image collections often requires the retrieval of the best subregions matching a given query. The support of such content-based retrieval requires not only the formulation of an appropriate scoring function for defining relevant subregions but also the design of new access methods that can scale to large databases. In this paper, we propose a solution to this problem of querying significant image subregions. We design a scoring scheme to measure the similarity of subregions. Our similarity measure extends to any image descriptor. All the images are tiled and each alignment of the query and a database image produces a tile score matrix. We show that the problem of finding the best connected subregion from this matrix is NP-hard and develop a dynamic programming heuristic. With this heuristic, we develop two index based scalable search strategies, TARS and SPARS, to query patterns in a large image repository. These strategies are general enough to work with other scoring schemes and heuristics. Experimental results on real image datasets show that TARS saves more than 87% query time on small queries, and SPARS saves up to 52% query time on large queries as compared to linear search. Qualitative tests on synthetic and real datasets achieve precision of more than 80%.
[ { "version": "v1", "created": "Fri, 19 Jun 2009 06:57:51 GMT" } ]
2010-03-09T00:00:00
[ [ "Singh", "Vishwakarma", "" ], [ "Bhattacharya", "Arnab", "" ], [ "Singh", "Ambuj K.", "" ] ]
TITLE: Finding Significant Subregions in Large Image Databases ABSTRACT: Images have become an important data source in many scientific and commercial domains. Analysis and exploration of image collections often requires the retrieval of the best subregions matching a given query. The support of such content-based retrieval requires not only the formulation of an appropriate scoring function for defining relevant subregions but also the design of new access methods that can scale to large databases. In this paper, we propose a solution to this problem of querying significant image subregions. We design a scoring scheme to measure the similarity of subregions. Our similarity measure extends to any image descriptor. All the images are tiled and each alignment of the query and a database image produces a tile score matrix. We show that the problem of finding the best connected subregion from this matrix is NP-hard and develop a dynamic programming heuristic. With this heuristic, we develop two index based scalable search strategies, TARS and SPARS, to query patterns in a large image repository. These strategies are general enough to work with other scoring schemes and heuristics. Experimental results on real image datasets show that TARS saves more than 87% query time on small queries, and SPARS saves up to 52% query time on large queries as compared to linear search. Qualitative tests on synthetic and real datasets achieve precision of more than 80%.
no_new_dataset
0.950134
0909.3169
Purushottam Kar
Arnab Bhattacharya, Purushottam Kar and Manjish Pal
On Low Distortion Embeddings of Statistical Distance Measures into Low Dimensional Spaces
18 pages, The short version of this paper was accepted for presentation at the 20th International Conference on Database and Expert Systems Applications, DEXA 2009
Database and Expert Systems Applications (DEXA) 2009
10.1007/978-3-642-03573-9_13
null
cs.CG cs.DB
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Statistical distance measures have found wide applicability in information retrieval tasks that typically involve high dimensional datasets. In order to reduce the storage space and ensure efficient performance of queries, dimensionality reduction while preserving the inter-point similarity is highly desirable. In this paper, we investigate various statistical distance measures from the point of view of discovering low distortion embeddings into low-dimensional spaces. More specifically, we consider the Mahalanobis distance measure, the Bhattacharyya class of divergences and the Kullback-Leibler divergence. We present a dimensionality reduction method based on the Johnson-Lindenstrauss Lemma for the Mahalanobis measure that achieves arbitrarily low distortion. By using the Johnson-Lindenstrauss Lemma again, we further demonstrate that the Bhattacharyya distance admits dimensionality reduction with arbitrarily low additive error. We also examine the question of embeddability into metric spaces for these distance measures due to the availability of efficient indexing schemes on metric spaces. We provide explicit constructions of point sets under the Bhattacharyya and the Kullback-Leibler divergences whose embeddings into any metric space incur arbitrarily large distortions. We show that the lower bound presented for Bhattacharyya distance is nearly tight by providing an embedding that approaches the lower bound for relatively small dimensional datasets.
[ { "version": "v1", "created": "Thu, 17 Sep 2009 09:29:48 GMT" } ]
2010-03-09T00:00:00
[ [ "Bhattacharya", "Arnab", "" ], [ "Kar", "Purushottam", "" ], [ "Pal", "Manjish", "" ] ]
TITLE: On Low Distortion Embeddings of Statistical Distance Measures into Low Dimensional Spaces ABSTRACT: Statistical distance measures have found wide applicability in information retrieval tasks that typically involve high dimensional datasets. In order to reduce the storage space and ensure efficient performance of queries, dimensionality reduction while preserving the inter-point similarity is highly desirable. In this paper, we investigate various statistical distance measures from the point of view of discovering low distortion embeddings into low-dimensional spaces. More specifically, we consider the Mahalanobis distance measure, the Bhattacharyya class of divergences and the Kullback-Leibler divergence. We present a dimensionality reduction method based on the Johnson-Lindenstrauss Lemma for the Mahalanobis measure that achieves arbitrarily low distortion. By using the Johnson-Lindenstrauss Lemma again, we further demonstrate that the Bhattacharyya distance admits dimensionality reduction with arbitrarily low additive error. We also examine the question of embeddability into metric spaces for these distance measures due to the availability of efficient indexing schemes on metric spaces. We provide explicit constructions of point sets under the Bhattacharyya and the Kullback-Leibler divergences whose embeddings into any metric space incur arbitrarily large distortions. We show that the lower bound presented for Bhattacharyya distance is nearly tight by providing an embedding that approaches the lower bound for relatively small dimensional datasets.
no_new_dataset
0.948965
1001.2625
Arnab Bhattacharya
Arnab Bhattacharya, Abhishek Bhowmick, Ambuj K. Singh
Finding top-k similar pairs of objects annotated with terms from an ontology
17 pages, 13 figures
null
null
null
cs.DB
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
With the growing focus on semantic searches and interpretations, an increasing number of standardized vocabularies and ontologies are being designed and used to describe data. We investigate the querying of objects described by a tree-structured ontology. Specifically, we consider the case of finding the top-k best pairs of objects that have been annotated with terms from such an ontology when the object descriptions are available only at runtime. We consider three distance measures. The first one defines the object distance as the minimum pairwise distance between the sets of terms describing them, and the second one defines the distance as the average pairwise term distance. The third and most useful distance measure, earth mover's distance, finds the best way of matching the terms and computes the distance corresponding to this best matching. We develop lower bounds that can be aggregated progressively and utilize them to speed up the search for top-k object pairs when the earth mover's distance is used. For the minimum pairwise distance, we devise an algorithm that runs in O(D + Tk log k) time, where D is the total information size and T is the total number of terms in the ontology. We also develop a novel best-first search strategy for the average pairwise distance that utilizes lower bounds generated in an ordered manner. Experiments on real and synthetic datasets demonstrate the practicality and scalability of our algorithms.
[ { "version": "v1", "created": "Fri, 15 Jan 2010 07:01:37 GMT" }, { "version": "v2", "created": "Sat, 6 Mar 2010 11:23:28 GMT" } ]
2010-03-09T00:00:00
[ [ "Bhattacharya", "Arnab", "" ], [ "Bhowmick", "Abhishek", "" ], [ "Singh", "Ambuj K.", "" ] ]
TITLE: Finding top-k similar pairs of objects annotated with terms from an ontology ABSTRACT: With the growing focus on semantic searches and interpretations, an increasing number of standardized vocabularies and ontologies are being designed and used to describe data. We investigate the querying of objects described by a tree-structured ontology. Specifically, we consider the case of finding the top-k best pairs of objects that have been annotated with terms from such an ontology when the object descriptions are available only at runtime. We consider three distance measures. The first one defines the object distance as the minimum pairwise distance between the sets of terms describing them, and the second one defines the distance as the average pairwise term distance. The third and most useful distance measure, earth mover's distance, finds the best way of matching the terms and computes the distance corresponding to this best matching. We develop lower bounds that can be aggregated progressively and utilize them to speed up the search for top-k object pairs when the earth mover's distance is used. For the minimum pairwise distance, we devise an algorithm that runs in O(D + Tk log k) time, where D is the total information size and T is the total number of terms in the ontology. We also develop a novel best-first search strategy for the average pairwise distance that utilizes lower bounds generated in an ordered manner. Experiments on real and synthetic datasets demonstrate the practicality and scalability of our algorithms.
no_new_dataset
0.952838
0910.0668
Ahmed Abdel-Gawad
Yuan Qi, Ahmed H. Abdel-Gawad and Thomas P. Minka
Variable sigma Gaussian processes: An expectation propagation perspective
null
null
null
null
cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Gaussian processes (GPs) provide a probabilistic nonparametric representation of functions in regression, classification, and other problems. Unfortunately, exact learning with GPs is intractable for large datasets. A variety of approximate GP methods have been proposed that essentially map the large dataset into a small set of basis points. The most advanced of these, the variable-sigma GP (VSGP) (Walder et al., 2008), allows each basis point to have its own length scale. However, VSGP was only derived for regression. We describe how VSGP can be applied to classification and other problems, by deriving it as an expectation propagation algorithm. In this view, sparse GP approximations correspond to a KL-projection of the true posterior onto a compact exponential family of GPs. VSGP constitutes one such family, and we show how to enlarge this family to get additional accuracy. In particular, we show that endowing each basis point with its own full covariance matrix provides a significant increase in approximation power.
[ { "version": "v1", "created": "Mon, 5 Oct 2009 03:30:13 GMT" }, { "version": "v2", "created": "Wed, 7 Oct 2009 21:52:48 GMT" } ]
2010-02-23T00:00:00
[ [ "Qi", "Yuan", "" ], [ "Abdel-Gawad", "Ahmed H.", "" ], [ "Minka", "Thomas P.", "" ] ]
TITLE: Variable sigma Gaussian processes: An expectation propagation perspective ABSTRACT: Gaussian processes (GPs) provide a probabilistic nonparametric representation of functions in regression, classification, and other problems. Unfortunately, exact learning with GPs is intractable for large datasets. A variety of approximate GP methods have been proposed that essentially map the large dataset into a small set of basis points. The most advanced of these, the variable-sigma GP (VSGP) (Walder et al., 2008), allows each basis point to have its own length scale. However, VSGP was only derived for regression. We describe how VSGP can be applied to classification and other problems, by deriving it as an expectation propagation algorithm. In this view, sparse GP approximations correspond to a KL-projection of the true posterior onto a compact exponential family of GPs. VSGP constitutes one such family, and we show how to enlarge this family to get additional accuracy. In particular, we show that endowing each basis point with its own full covariance matrix provides a significant increase in approximation power.
no_new_dataset
0.946001
1002.3195
Mahmud Hossain
M. Shahriar Hossain, Michael Narayan and Naren Ramakrishnan
Efficiently Discovering Hammock Paths from Induced Similarity Networks
null
null
null
null
cs.AI cs.DB
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Similarity networks are important abstractions in many information management applications such as recommender systems, corpora analysis, and medical informatics. For instance, by inducing similarity networks between movies rated similarly by users, or between documents containing common terms, and or between clinical trials involving the same themes, we can aim to find the global structure of connectivities underlying the data, and use the network as a basis to make connections between seemingly disparate entities. In the above applications, composing similarities between objects of interest finds uses in serendipitous recommendation, in storytelling, and in clinical diagnosis, respectively. We present an algorithmic framework for traversing similarity paths using the notion of `hammock' paths which are generalization of traditional paths. Our framework is exploratory in nature so that, given starting and ending objects of interest, it explores candidate objects for path following, and heuristics to admissibly estimate the potential for paths to lead to a desired destination. We present three diverse applications: exploring movie similarities in the Netflix dataset, exploring abstract similarities across the PubMed corpus, and exploring description similarities in a database of clinical trials. Experimental results demonstrate the potential of our approach for unstructured knowledge discovery in similarity networks.
[ { "version": "v1", "created": "Wed, 17 Feb 2010 04:07:06 GMT" } ]
2010-02-18T00:00:00
[ [ "Hossain", "M. Shahriar", "" ], [ "Narayan", "Michael", "" ], [ "Ramakrishnan", "Naren", "" ] ]
TITLE: Efficiently Discovering Hammock Paths from Induced Similarity Networks ABSTRACT: Similarity networks are important abstractions in many information management applications such as recommender systems, corpora analysis, and medical informatics. For instance, by inducing similarity networks between movies rated similarly by users, or between documents containing common terms, and or between clinical trials involving the same themes, we can aim to find the global structure of connectivities underlying the data, and use the network as a basis to make connections between seemingly disparate entities. In the above applications, composing similarities between objects of interest finds uses in serendipitous recommendation, in storytelling, and in clinical diagnosis, respectively. We present an algorithmic framework for traversing similarity paths using the notion of `hammock' paths which are generalization of traditional paths. Our framework is exploratory in nature so that, given starting and ending objects of interest, it explores candidate objects for path following, and heuristics to admissibly estimate the potential for paths to lead to a desired destination. We present three diverse applications: exploring movie similarities in the Netflix dataset, exploring abstract similarities across the PubMed corpus, and exploring description similarities in a database of clinical trials. Experimental results demonstrate the potential of our approach for unstructured knowledge discovery in similarity networks.
no_new_dataset
0.946001
1002.2780
Ruslan Salakhutdinov
Ruslan Salakhutdinov, Nathan Srebro
Collaborative Filtering in a Non-Uniform World: Learning with the Weighted Trace Norm
9 pages
null
null
null
cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that matrix completion with trace-norm regularization can be significantly hurt when entries of the matrix are sampled non-uniformly. We introduce a weighted version of the trace-norm regularizer that works well also with non-uniform sampling. Our experimental results demonstrate that the weighted trace-norm regularization indeed yields significant gains on the (highly non-uniformly sampled) Netflix dataset.
[ { "version": "v1", "created": "Sun, 14 Feb 2010 16:37:04 GMT" } ]
2010-02-16T00:00:00
[ [ "Salakhutdinov", "Ruslan", "" ], [ "Srebro", "Nathan", "" ] ]
TITLE: Collaborative Filtering in a Non-Uniform World: Learning with the Weighted Trace Norm ABSTRACT: We show that matrix completion with trace-norm regularization can be significantly hurt when entries of the matrix are sampled non-uniformly. We introduce a weighted version of the trace-norm regularizer that works well also with non-uniform sampling. Our experimental results demonstrate that the weighted trace-norm regularization indeed yields significant gains on the (highly non-uniformly sampled) Netflix dataset.
no_new_dataset
0.950319
0908.0050
Julien Mairal
Julien Mairal (INRIA Rocquencourt), Francis Bach (INRIA Rocquencourt), Jean Ponce (INRIA Rocquencourt, LIENS), Guillermo Sapiro
Online Learning for Matrix Factorization and Sparse Coding
revised version
Journal of Machine Learning Research 11 (2010) 19--60
null
null
stat.ML cs.LG math.OC
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Sparse coding--that is, modelling data vectors as sparse linear combinations of basis elements--is widely used in machine learning, neuroscience, signal processing, and statistics. This paper focuses on the large-scale matrix factorization problem that consists of learning the basis set, adapting it to specific data. Variations of this problem include dictionary learning in signal processing, non-negative matrix factorization and sparse principal component analysis. In this paper, we propose to address these tasks with a new online optimization algorithm, based on stochastic approximations, which scales up gracefully to large datasets with millions of training samples, and extends naturally to various matrix factorization formulations, making it suitable for a wide range of learning problems. A proof of convergence is presented, along with experiments with natural images and genomic data demonstrating that it leads to state-of-the-art performance in terms of speed and optimization for both small and large datasets.
[ { "version": "v1", "created": "Sat, 1 Aug 2009 06:09:18 GMT" }, { "version": "v2", "created": "Thu, 11 Feb 2010 07:33:02 GMT" } ]
2010-02-11T00:00:00
[ [ "Mairal", "Julien", "", "INRIA Rocquencourt" ], [ "Bach", "Francis", "", "INRIA Rocquencourt" ], [ "Ponce", "Jean", "", "INRIA Rocquencourt, LIENS" ], [ "Sapiro", "Guillermo", "" ] ]
TITLE: Online Learning for Matrix Factorization and Sparse Coding ABSTRACT: Sparse coding--that is, modelling data vectors as sparse linear combinations of basis elements--is widely used in machine learning, neuroscience, signal processing, and statistics. This paper focuses on the large-scale matrix factorization problem that consists of learning the basis set, adapting it to specific data. Variations of this problem include dictionary learning in signal processing, non-negative matrix factorization and sparse principal component analysis. In this paper, we propose to address these tasks with a new online optimization algorithm, based on stochastic approximations, which scales up gracefully to large datasets with millions of training samples, and extends naturally to various matrix factorization formulations, making it suitable for a wide range of learning problems. A proof of convergence is presented, along with experiments with natural images and genomic data demonstrating that it leads to state-of-the-art performance in terms of speed and optimization for both small and large datasets.
no_new_dataset
0.947769
1002.1156
Vishal Goyal
M. Babu Reddy, L. S. S. Reddy
Dimensionality Reduction: An Empirical Study on the Usability of IFE-CF (Independent Feature Elimination- by C-Correlation and F-Correlation) Measures
International Journal of Computer Science Issues, IJCSI, Vol. 7, Issue 1, No. 1, January 2010, http://ijcsi.org
International Journal of Computer Science Issues, IJCSI, Vol. 7, Issue 1, No. 1, January 2010, http://ijcsi.org/articles/Dimensionality-Reduction-An-Empirical-Study-on-the-Usability-of-IFE-CF-(Independent-Feature-Elimination-by-C-Correlation-and-F-Correlation)-Measures.php
null
null
cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The recent increase in dimensionality of data has thrown a great challenge to the existing dimensionality reduction methods in terms of their effectiveness. Dimensionality reduction has emerged as one of the significant preprocessing steps in machine learning applications and has been effective in removing inappropriate data, increasing learning accuracy, and improving comprehensibility. Feature redundancy exercises great influence on the performance of classification process. Towards the better classification performance, this paper addresses the usefulness of truncating the highly correlated and redundant attributes. Here, an effort has been made to verify the utility of dimensionality reduction by applying LVQ (Learning Vector Quantization) method on two Benchmark datasets of 'Pima Indian Diabetic patients' and 'Lung cancer patients'.
[ { "version": "v1", "created": "Fri, 5 Feb 2010 08:59:05 GMT" } ]
2010-02-10T00:00:00
[ [ "Reddy", "M. Babu", "" ], [ "Reddy", "L. S. S.", "" ] ]
TITLE: Dimensionality Reduction: An Empirical Study on the Usability of IFE-CF (Independent Feature Elimination- by C-Correlation and F-Correlation) Measures ABSTRACT: The recent increase in dimensionality of data has thrown a great challenge to the existing dimensionality reduction methods in terms of their effectiveness. Dimensionality reduction has emerged as one of the significant preprocessing steps in machine learning applications and has been effective in removing inappropriate data, increasing learning accuracy, and improving comprehensibility. Feature redundancy exercises great influence on the performance of classification process. Towards the better classification performance, this paper addresses the usefulness of truncating the highly correlated and redundant attributes. Here, an effort has been made to verify the utility of dimensionality reduction by applying LVQ (Learning Vector Quantization) method on two Benchmark datasets of 'Pima Indian Diabetic patients' and 'Lung cancer patients'.
no_new_dataset
0.949295
1002.1104
Fabio Vandin
Adam Kirsch, Michael Mitzenmacher, Andrea Pietracaprina, Geppino Pucci, Eli Upfal, Fabio Vandin
An Efficient Rigorous Approach for Identifying Statistically Significant Frequent Itemsets
A preliminary version of this work was presented in ACM PODS 2009. 20 pages, 0 figures
null
null
null
cs.DB cs.DS
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
As advances in technology allow for the collection, storage, and analysis of vast amounts of data, the task of screening and assessing the significance of discovered patterns is becoming a major challenge in data mining applications. In this work, we address significance in the context of frequent itemset mining. Specifically, we develop a novel methodology to identify a meaningful support threshold s* for a dataset, such that the number of itemsets with support at least s* represents a substantial deviation from what would be expected in a random dataset with the same number of transactions and the same individual item frequencies. These itemsets can then be flagged as statistically significant with a small false discovery rate. We present extensive experimental results to substantiate the effectiveness of our methodology.
[ { "version": "v1", "created": "Thu, 4 Feb 2010 23:33:47 GMT" } ]
2010-02-08T00:00:00
[ [ "Kirsch", "Adam", "" ], [ "Mitzenmacher", "Michael", "" ], [ "Pietracaprina", "Andrea", "" ], [ "Pucci", "Geppino", "" ], [ "Upfal", "Eli", "" ], [ "Vandin", "Fabio", "" ] ]
TITLE: An Efficient Rigorous Approach for Identifying Statistically Significant Frequent Itemsets ABSTRACT: As advances in technology allow for the collection, storage, and analysis of vast amounts of data, the task of screening and assessing the significance of discovered patterns is becoming a major challenge in data mining applications. In this work, we address significance in the context of frequent itemset mining. Specifically, we develop a novel methodology to identify a meaningful support threshold s* for a dataset, such that the number of itemsets with support at least s* represents a substantial deviation from what would be expected in a random dataset with the same number of transactions and the same individual item frequencies. These itemsets can then be flagged as statistically significant with a small false discovery rate. We present extensive experimental results to substantiate the effectiveness of our methodology.
no_new_dataset
0.950732
1002.1144
Vishal Goyal
M. Ramaswami, R. Bhaskaran
A CHAID Based Performance Prediction Model in Educational Data Mining
International Journal of Computer Science Issues, IJCSI, Vol. 7, Issue 1, No. 1, January 2010, http://ijcsi.org/articles/A-CHAID-Based-Performance-Prediction-Model-in-Educational-Data-Mining.php
International Journal of Computer Science Issues, IJCSI, Vol. 7, Issue 1, No. 1, January 2010, http://ijcsi.org/articles/A-CHAID-Based-Performance-Prediction-Model-in-Educational-Data-Mining.php
null
null
cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The performance in higher secondary school education in India is a turning point in the academic lives of all students. As this academic performance is influenced by many factors, it is essential to develop predictive data mining model for students' performance so as to identify the slow learners and study the influence of the dominant factors on their academic performance. In the present investigation, a survey cum experimental methodology was adopted to generate a database and it was constructed from a primary and a secondary source. While the primary data was collected from the regular students, the secondary data was gathered from the school and office of the Chief Educational Officer (CEO). A total of 1000 datasets of the year 2006 from five different schools in three different districts of Tamilnadu were collected. The raw data was preprocessed in terms of filling up missing values, transforming values in one form into another and relevant attribute/ variable selection. As a result, we had 772 student records, which were used for CHAID prediction model construction. A set of prediction rules were extracted from CHIAD prediction model and the efficiency of the generated CHIAD prediction model was found. The accuracy of the present model was compared with other model and it has been found to be satisfactory.
[ { "version": "v1", "created": "Fri, 5 Feb 2010 08:27:17 GMT" } ]
2010-02-08T00:00:00
[ [ "Ramaswami", "M.", "" ], [ "Bhaskaran", "R.", "" ] ]
TITLE: A CHAID Based Performance Prediction Model in Educational Data Mining ABSTRACT: The performance in higher secondary school education in India is a turning point in the academic lives of all students. As this academic performance is influenced by many factors, it is essential to develop predictive data mining model for students' performance so as to identify the slow learners and study the influence of the dominant factors on their academic performance. In the present investigation, a survey cum experimental methodology was adopted to generate a database and it was constructed from a primary and a secondary source. While the primary data was collected from the regular students, the secondary data was gathered from the school and office of the Chief Educational Officer (CEO). A total of 1000 datasets of the year 2006 from five different schools in three different districts of Tamilnadu were collected. The raw data was preprocessed in terms of filling up missing values, transforming values in one form into another and relevant attribute/ variable selection. As a result, we had 772 student records, which were used for CHAID prediction model construction. A set of prediction rules were extracted from CHIAD prediction model and the efficiency of the generated CHIAD prediction model was found. The accuracy of the present model was compared with other model and it has been found to be satisfactory.
no_new_dataset
0.875787
1002.0414
Dakshina Ranjan Kisku
Dakshina Ranjan Kisku, Phalguni Gupta, Jamuna Kanta Sing
Feature Level Fusion of Biometrics Cues: Human Identification with Doddingtons Caricature
8 pages, 3 figures
null
null
null
cs.CV cs.AI
http://creativecommons.org/licenses/by/3.0/
This paper presents a multimodal biometric system of fingerprint and ear biometrics. Scale Invariant Feature Transform (SIFT) descriptor based feature sets extracted from fingerprint and ear are fused. The fused set is encoded by K-medoids partitioning approach with less number of feature points in the set. K-medoids partition the whole dataset into clusters to minimize the error between data points belonging to the clusters and its center. Reduced feature set is used to match between two biometric sets. Matching scores are generated using wolf-lamb user-dependent feature weighting scheme introduced by Doddington. The technique is tested to exhibit its robust performance.
[ { "version": "v1", "created": "Tue, 2 Feb 2010 08:12:23 GMT" } ]
2010-02-03T00:00:00
[ [ "Kisku", "Dakshina Ranjan", "" ], [ "Gupta", "Phalguni", "" ], [ "Sing", "Jamuna Kanta", "" ] ]
TITLE: Feature Level Fusion of Biometrics Cues: Human Identification with Doddingtons Caricature ABSTRACT: This paper presents a multimodal biometric system of fingerprint and ear biometrics. Scale Invariant Feature Transform (SIFT) descriptor based feature sets extracted from fingerprint and ear are fused. The fused set is encoded by K-medoids partitioning approach with less number of feature points in the set. K-medoids partition the whole dataset into clusters to minimize the error between data points belonging to the clusters and its center. Reduced feature set is used to match between two biometric sets. Matching scores are generated using wolf-lamb user-dependent feature weighting scheme introduced by Doddington. The technique is tested to exhibit its robust performance.
no_new_dataset
0.95297
0912.2548
Grigorios Loukides
Grigorios Loukides, Aris Gkoulalas-Divanis and Bradley Malin
Towards Utility-driven Anonymization of Transactions
null
null
null
null
cs.DB cs.CR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Publishing person-specific transactions in an anonymous form is increasingly required by organizations. Recent approaches ensure that potentially identifying information (e.g., a set of diagnosis codes) cannot be used to link published transactions to persons' identities, but all are limited in application because they incorporate coarse privacy requirements (e.g., protecting a certain set of m diagnosis codes requires protecting all m-sized sets), do not integrate utility requirements, and tend to explore a small portion of the solution space. In this paper, we propose a more general framework for anonymizing transactional data under specific privacy and utility requirements. We model such requirements as constraints, investigate how these constraints can be specified, and propose COAT (COnstraint-based Anonymization of Transactions), an algorithm that anonymizes transactions using a flexible hierarchy-free generalization scheme to meet the specified constraints. Experiments with benchmark datasets verify that COAT significantly outperforms the current state-of-the-art algorithm in terms of data utility, while being comparable in terms of efficiency. The effectiveness of our approach is also demonstrated in a real-world scenario, which requires disseminating a private, patient-specific transactional dataset in a way that preserves both privacy and utility in intended studies.
[ { "version": "v1", "created": "Sun, 13 Dec 2009 23:30:24 GMT" }, { "version": "v2", "created": "Tue, 26 Jan 2010 05:26:00 GMT" } ]
2010-01-26T00:00:00
[ [ "Loukides", "Grigorios", "" ], [ "Gkoulalas-Divanis", "Aris", "" ], [ "Malin", "Bradley", "" ] ]
TITLE: Towards Utility-driven Anonymization of Transactions ABSTRACT: Publishing person-specific transactions in an anonymous form is increasingly required by organizations. Recent approaches ensure that potentially identifying information (e.g., a set of diagnosis codes) cannot be used to link published transactions to persons' identities, but all are limited in application because they incorporate coarse privacy requirements (e.g., protecting a certain set of m diagnosis codes requires protecting all m-sized sets), do not integrate utility requirements, and tend to explore a small portion of the solution space. In this paper, we propose a more general framework for anonymizing transactional data under specific privacy and utility requirements. We model such requirements as constraints, investigate how these constraints can be specified, and propose COAT (COnstraint-based Anonymization of Transactions), an algorithm that anonymizes transactions using a flexible hierarchy-free generalization scheme to meet the specified constraints. Experiments with benchmark datasets verify that COAT significantly outperforms the current state-of-the-art algorithm in terms of data utility, while being comparable in terms of efficiency. The effectiveness of our approach is also demonstrated in a real-world scenario, which requires disseminating a private, patient-specific transactional dataset in a way that preserves both privacy and utility in intended studies.
no_new_dataset
0.9463
1001.3824
Federico Sacerdoti MSc
Federico D. Sacerdoti
Performance and Fault Tolerance in the StoreTorrent Parallel Filesystem
13 pages, 7 figures
null
null
null
cs.DC
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
With a goal of supporting the timely and cost-effective analysis of Terabyte datasets on commodity components, we present and evaluate StoreTorrent, a simple distributed filesystem with integrated fault tolerance for efficient handling of small data records. Our contributions include an application-OS pipelining technique and metadata structure to increase small write and read performance by a factor of 1-10, and the use of peer-to-peer communication of replica-location indexes to avoid transferring data during parallel analysis even in a degraded state. We evaluated StoreTorrent, PVFS, and Gluster filesystems using 70 storage nodes and 560 parallel clients on an 8-core/node Ethernet cluster with directly attached SATA disks. StoreTorrent performed parallel small writes at an aggregate rate of 1.69 GB/s, and supported reads over the network at 8.47 GB/s. We ported a parallel analysis task and demonstrate it achieved parallel reads at the full aggregate speed of the storage node local filesystems.
[ { "version": "v1", "created": "Thu, 21 Jan 2010 15:17:30 GMT" } ]
2010-01-22T00:00:00
[ [ "Sacerdoti", "Federico D.", "" ] ]
TITLE: Performance and Fault Tolerance in the StoreTorrent Parallel Filesystem ABSTRACT: With a goal of supporting the timely and cost-effective analysis of Terabyte datasets on commodity components, we present and evaluate StoreTorrent, a simple distributed filesystem with integrated fault tolerance for efficient handling of small data records. Our contributions include an application-OS pipelining technique and metadata structure to increase small write and read performance by a factor of 1-10, and the use of peer-to-peer communication of replica-location indexes to avoid transferring data during parallel analysis even in a degraded state. We evaluated StoreTorrent, PVFS, and Gluster filesystems using 70 storage nodes and 560 parallel clients on an 8-core/node Ethernet cluster with directly attached SATA disks. StoreTorrent performed parallel small writes at an aggregate rate of 1.69 GB/s, and supported reads over the network at 8.47 GB/s. We ported a parallel analysis task and demonstrate it achieved parallel reads at the full aggregate speed of the storage node local filesystems.
no_new_dataset
0.940298
1001.2921
Loet Leydesdorff
Willem Halffman and Loet Leydesdorff
Is Inequality Among Universities Increasing? Gini Coefficients and the Elusive Rise of Elite Universities
null
null
null
null
physics.soc-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
One of the unintended consequences of the New Public Management (NPM) in universities is often feared to be a division between elite institutions focused on research and large institutions with teaching missions. However, institutional isomorphisms provide counter-incentives. For example, university rankings focus on certain output parameters such as publications, but not on others (e.g., patents). In this study, we apply Gini coefficients to university rankings in order to assess whether universities are becoming more unequal, at the level of both the world and individual nations. Our results do not support the thesis that universities are becoming more unequal. If anything, we predominantly find homogenization, both at the level of the global comparisons and nationally. In a more restricted dataset (using only publications in the natural and life sciences), we find increasing inequality for those countries, which used NPM during the 1990s, but not during the 2000s. Our findings suggest that increased output steering from the policy side leads to a global conformation to performance standards.
[ { "version": "v1", "created": "Sun, 17 Jan 2010 19:36:29 GMT" } ]
2010-01-19T00:00:00
[ [ "Halffman", "Willem", "" ], [ "Leydesdorff", "Loet", "" ] ]
TITLE: Is Inequality Among Universities Increasing? Gini Coefficients and the Elusive Rise of Elite Universities ABSTRACT: One of the unintended consequences of the New Public Management (NPM) in universities is often feared to be a division between elite institutions focused on research and large institutions with teaching missions. However, institutional isomorphisms provide counter-incentives. For example, university rankings focus on certain output parameters such as publications, but not on others (e.g., patents). In this study, we apply Gini coefficients to university rankings in order to assess whether universities are becoming more unequal, at the level of both the world and individual nations. Our results do not support the thesis that universities are becoming more unequal. If anything, we predominantly find homogenization, both at the level of the global comparisons and nationally. In a more restricted dataset (using only publications in the natural and life sciences), we find increasing inequality for those countries, which used NPM during the 1990s, but not during the 2000s. Our findings suggest that increased output steering from the policy side leads to a global conformation to performance standards.
no_new_dataset
0.938969
1001.2922
Louis De Barros
Louis De Barros (UCD), Christopher J. Bean (UCD), Ivan Lokmer (UCD), Gilberto Saccorotti, Luciano Zucarello, Gareth O'Brien (UCD), Jean-Philippe M\'etaxian (LGIT), Domenico Patan\`e
Source geometry from exceptionally high resolution long period event observations at Mt Etna during the 2008 eruption
null
Geophysical Research Letters 36 (2009) L24305
10.1029/2009GL041273
null
physics.geo-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
During the second half of June, 2008, 50 broadband seismic stations were deployed on Mt Etna volcano in close proximity to the summit, allowing us to observe seismic activity with exceptionally high resolution. 129 long period events (LP) with dominant frequencies ranging between 0.3 and 1.2 Hz, were extracted from this dataset. These events form two families of similar waveforms with different temporal distributions. Event locations are performed by cross-correlating signals for all pairs of stations in a two-step scheme. In the first step, the absolute location of the centre of the clusters was found. In the second step, all events are located using this position. The hypocentres are found at shallow depths (20 to 700 m deep) below the summit craters. The very high location resolution allows us to detect the temporal migration of the events along a dike-like structure and 2 pipe shaped bodies, yielding an unprecedented view of some elements of the shallow plumbing system at Mount Etna. These events do not seem to be a direct indicator of the ongoing lava flow or magma upwelling.
[ { "version": "v1", "created": "Sun, 17 Jan 2010 19:43:41 GMT" } ]
2010-01-19T00:00:00
[ [ "De Barros", "Louis", "", "UCD" ], [ "Bean", "Christopher J.", "", "UCD" ], [ "Lokmer", "Ivan", "", "UCD" ], [ "Saccorotti", "Gilberto", "", "UCD" ], [ "Zucarello", "Luciano", "", "UCD" ], [ "O'Brien", "Gareth", "", "UCD" ], [ "Métaxian", "Jean-Philippe", "", "LGIT" ], [ "Patanè", "Domenico", "" ] ]
TITLE: Source geometry from exceptionally high resolution long period event observations at Mt Etna during the 2008 eruption ABSTRACT: During the second half of June, 2008, 50 broadband seismic stations were deployed on Mt Etna volcano in close proximity to the summit, allowing us to observe seismic activity with exceptionally high resolution. 129 long period events (LP) with dominant frequencies ranging between 0.3 and 1.2 Hz, were extracted from this dataset. These events form two families of similar waveforms with different temporal distributions. Event locations are performed by cross-correlating signals for all pairs of stations in a two-step scheme. In the first step, the absolute location of the centre of the clusters was found. In the second step, all events are located using this position. The hypocentres are found at shallow depths (20 to 700 m deep) below the summit craters. The very high location resolution allows us to detect the temporal migration of the events along a dike-like structure and 2 pipe shaped bodies, yielding an unprecedented view of some elements of the shallow plumbing system at Mount Etna. These events do not seem to be a direct indicator of the ongoing lava flow or magma upwelling.
no_new_dataset
0.89303
1001.1221
Paolo Piro
Paolo Piro, Richard Nock, Frank Nielsen, Michel Barlaud
Boosting k-NN for categorization of natural scenes
under revision for IJCV
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The k-nearest neighbors (k-NN) classification rule has proven extremely successful in countless many computer vision applications. For example, image categorization often relies on uniform voting among the nearest prototypes in the space of descriptors. In spite of its good properties, the classic k-NN rule suffers from high variance when dealing with sparse prototype datasets in high dimensions. A few techniques have been proposed to improve k-NN classification, which rely on either deforming the nearest neighborhood relationship or modifying the input space. In this paper, we propose a novel boosting algorithm, called UNN (Universal Nearest Neighbors), which induces leveraged k-NN, thus generalizing the classic k-NN rule. We redefine the voting rule as a strong classifier that linearly combines predictions from the k closest prototypes. Weak classifiers are learned by UNN so as to minimize a surrogate risk. A major feature of UNN is the ability to learn which prototypes are the most relevant for a given class, thus allowing one for effective data reduction. Experimental results on the synthetic two-class dataset of Ripley show that such a filtering strategy is able to reject "noisy" prototypes. We carried out image categorization experiments on a database containing eight classes of natural scenes. We show that our method outperforms significantly the classic k-NN classification, while enabling significant reduction of the computational cost by means of data filtering.
[ { "version": "v1", "created": "Fri, 8 Jan 2010 08:30:51 GMT" } ]
2010-01-11T00:00:00
[ [ "Piro", "Paolo", "" ], [ "Nock", "Richard", "" ], [ "Nielsen", "Frank", "" ], [ "Barlaud", "Michel", "" ] ]
TITLE: Boosting k-NN for categorization of natural scenes ABSTRACT: The k-nearest neighbors (k-NN) classification rule has proven extremely successful in countless many computer vision applications. For example, image categorization often relies on uniform voting among the nearest prototypes in the space of descriptors. In spite of its good properties, the classic k-NN rule suffers from high variance when dealing with sparse prototype datasets in high dimensions. A few techniques have been proposed to improve k-NN classification, which rely on either deforming the nearest neighborhood relationship or modifying the input space. In this paper, we propose a novel boosting algorithm, called UNN (Universal Nearest Neighbors), which induces leveraged k-NN, thus generalizing the classic k-NN rule. We redefine the voting rule as a strong classifier that linearly combines predictions from the k closest prototypes. Weak classifiers are learned by UNN so as to minimize a surrogate risk. A major feature of UNN is the ability to learn which prototypes are the most relevant for a given class, thus allowing one for effective data reduction. Experimental results on the synthetic two-class dataset of Ripley show that such a filtering strategy is able to reject "noisy" prototypes. We carried out image categorization experiments on a database containing eight classes of natural scenes. We show that our method outperforms significantly the classic k-NN classification, while enabling significant reduction of the computational cost by means of data filtering.
no_new_dataset
0.948251
1001.1020
Ping Li
Ping Li
An Empirical Evaluation of Four Algorithms for Multi-Class Classification: Mart, ABC-Mart, Robust LogitBoost, and ABC-LogitBoost
null
null
null
null
cs.LG cs.AI cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This empirical study is mainly devoted to comparing four tree-based boosting algorithms: mart, abc-mart, robust logitboost, and abc-logitboost, for multi-class classification on a variety of publicly available datasets. Some of those datasets have been thoroughly tested in prior studies using a broad range of classification algorithms including SVM, neural nets, and deep learning. In terms of the empirical classification errors, our experiment results demonstrate: 1. Abc-mart considerably improves mart. 2. Abc-logitboost considerably improves (robust) logitboost. 3. Robust) logitboost} considerably improves mart on most datasets. 4. Abc-logitboost considerably improves abc-mart on most datasets. 5. These four boosting algorithms (especially abc-logitboost) outperform SVM on many datasets. 6. Compared to the best deep learning methods, these four boosting algorithms (especially abc-logitboost) are competitive.
[ { "version": "v1", "created": "Thu, 7 Jan 2010 06:34:21 GMT" } ]
2010-01-08T00:00:00
[ [ "Li", "Ping", "" ] ]
TITLE: An Empirical Evaluation of Four Algorithms for Multi-Class Classification: Mart, ABC-Mart, Robust LogitBoost, and ABC-LogitBoost ABSTRACT: This empirical study is mainly devoted to comparing four tree-based boosting algorithms: mart, abc-mart, robust logitboost, and abc-logitboost, for multi-class classification on a variety of publicly available datasets. Some of those datasets have been thoroughly tested in prior studies using a broad range of classification algorithms including SVM, neural nets, and deep learning. In terms of the empirical classification errors, our experiment results demonstrate: 1. Abc-mart considerably improves mart. 2. Abc-logitboost considerably improves (robust) logitboost. 3. Robust) logitboost} considerably improves mart on most datasets. 4. Abc-logitboost considerably improves abc-mart on most datasets. 5. These four boosting algorithms (especially abc-logitboost) outperform SVM on many datasets. 6. Compared to the best deep learning methods, these four boosting algorithms (especially abc-logitboost) are competitive.
no_new_dataset
0.949153
1001.1079
Ricardo Silva
Ricardo Silva
Measuring Latent Causal Structure
null
null
null
null
cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Discovering latent representations of the observed world has become increasingly more relevant in data analysis. Much of the effort concentrates on building latent variables which can be used in prediction problems, such as classification and regression. A related goal of learning latent structure from data is that of identifying which hidden common causes generate the observations, such as in applications that require predicting the effect of policies. This will be the main problem tackled in our contribution: given a dataset of indicators assumed to be generated by unknown and unmeasured common causes, we wish to discover which hidden common causes are those, and how they generate our data. This is possible under the assumption that observed variables are linear functions of the latent causes with additive noise. Previous results in the literature present solutions for the case where each observed variable is a noisy function of a single latent variable. We show how to extend the existing results for some cases where observed variables measure more than one latent variable.
[ { "version": "v1", "created": "Thu, 7 Jan 2010 14:41:21 GMT" } ]
2010-01-08T00:00:00
[ [ "Silva", "Ricardo", "" ] ]
TITLE: Measuring Latent Causal Structure ABSTRACT: Discovering latent representations of the observed world has become increasingly more relevant in data analysis. Much of the effort concentrates on building latent variables which can be used in prediction problems, such as classification and regression. A related goal of learning latent structure from data is that of identifying which hidden common causes generate the observations, such as in applications that require predicting the effect of policies. This will be the main problem tackled in our contribution: given a dataset of indicators assumed to be generated by unknown and unmeasured common causes, we wish to discover which hidden common causes are those, and how they generate our data. This is possible under the assumption that observed variables are linear functions of the latent causes with additive noise. Previous results in the literature present solutions for the case where each observed variable is a noisy function of a single latent variable. We show how to extend the existing results for some cases where observed variables measure more than one latent variable.
no_new_dataset
0.944228
0904.2037
Chunhua Shen
Chunhua Shen and Hanxi Li
Boosting through Optimization of Margin Distributions
9 pages. To publish/Published in IEEE Transactions on Neural Networks, 21(7), July 2010
null
null
null
cs.LG cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Boosting has attracted much research attention in the past decade. The success of boosting algorithms may be interpreted in terms of the margin theory. Recently it has been shown that generalization error of classifiers can be obtained by explicitly taking the margin distribution of the training data into account. Most of the current boosting algorithms in practice usually optimizes a convex loss function and do not make use of the margin distribution. In this work we design a new boosting algorithm, termed margin-distribution boosting (MDBoost), which directly maximizes the average margin and minimizes the margin variance simultaneously. This way the margin distribution is optimized. A totally-corrective optimization algorithm based on column generation is proposed to implement MDBoost. Experiments on UCI datasets show that MDBoost outperforms AdaBoost and LPBoost in most cases.
[ { "version": "v1", "created": "Tue, 14 Apr 2009 01:57:12 GMT" }, { "version": "v2", "created": "Tue, 17 Nov 2009 02:24:51 GMT" }, { "version": "v3", "created": "Wed, 6 Jan 2010 09:00:26 GMT" } ]
2010-01-06T00:00:00
[ [ "Shen", "Chunhua", "" ], [ "Li", "Hanxi", "" ] ]
TITLE: Boosting through Optimization of Margin Distributions ABSTRACT: Boosting has attracted much research attention in the past decade. The success of boosting algorithms may be interpreted in terms of the margin theory. Recently it has been shown that generalization error of classifiers can be obtained by explicitly taking the margin distribution of the training data into account. Most of the current boosting algorithms in practice usually optimizes a convex loss function and do not make use of the margin distribution. In this work we design a new boosting algorithm, termed margin-distribution boosting (MDBoost), which directly maximizes the average margin and minimizes the margin variance simultaneously. This way the margin distribution is optimized. A totally-corrective optimization algorithm based on column generation is proposed to implement MDBoost. Experiments on UCI datasets show that MDBoost outperforms AdaBoost and LPBoost in most cases.
no_new_dataset
0.941708
0912.5426
Xiaokui Xiao
Xiaokui Xiao, Ke Yi, Yufei Tao
The Hardness and Approximation Algorithms for L-Diversity
EDBT 2010
null
null
null
cs.DB
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The existing solutions to privacy preserving publication can be classified into the theoretical and heuristic categories. The former guarantees provably low information loss, whereas the latter incurs gigantic loss in the worst case, but is shown empirically to perform well on many real inputs. While numerous heuristic algorithms have been developed to satisfy advanced privacy principles such as l-diversity, t-closeness, etc., the theoretical category is currently limited to k-anonymity which is the earliest principle known to have severe vulnerability to privacy attacks. Motivated by this, we present the first theoretical study on l-diversity, a popular principle that is widely adopted in the literature. First, we show that optimal l-diverse generalization is NP-hard even when there are only 3 distinct sensitive values in the microdata. Then, an (l*d)-approximation algorithm is developed, where d is the dimensionality of the underlying dataset. This is the first known algorithm with a non-trivial bound on information loss. Extensive experiments with real datasets validate the effectiveness and efficiency of proposed solution.
[ { "version": "v1", "created": "Wed, 30 Dec 2009 08:31:10 GMT" } ]
2009-12-31T00:00:00
[ [ "Xiao", "Xiaokui", "" ], [ "Yi", "Ke", "" ], [ "Tao", "Yufei", "" ] ]
TITLE: The Hardness and Approximation Algorithms for L-Diversity ABSTRACT: The existing solutions to privacy preserving publication can be classified into the theoretical and heuristic categories. The former guarantees provably low information loss, whereas the latter incurs gigantic loss in the worst case, but is shown empirically to perform well on many real inputs. While numerous heuristic algorithms have been developed to satisfy advanced privacy principles such as l-diversity, t-closeness, etc., the theoretical category is currently limited to k-anonymity which is the earliest principle known to have severe vulnerability to privacy attacks. Motivated by this, we present the first theoretical study on l-diversity, a popular principle that is widely adopted in the literature. First, we show that optimal l-diverse generalization is NP-hard even when there are only 3 distinct sensitive values in the microdata. Then, an (l*d)-approximation algorithm is developed, where d is the dimensionality of the underlying dataset. This is the first known algorithm with a non-trivial bound on information loss. Extensive experiments with real datasets validate the effectiveness and efficiency of proposed solution.
no_new_dataset
0.945701
0903.3257
Marcus Hutter
Ke Zhang and Marcus Hutter and Huidong Jin
A New Local Distance-Based Outlier Detection Approach for Scattered Real-World Data
15 LaTeX pages, 7 figures, 2 tables, 1 algorithm, 2 theorems
Proc. 13th Pacific-Asia Conf. on Knowledge Discovery and Data Mining (PAKDD 2009) pages 813-822
null
null
cs.LG cs.IR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Detecting outliers which are grossly different from or inconsistent with the remaining dataset is a major challenge in real-world KDD applications. Existing outlier detection methods are ineffective on scattered real-world datasets due to implicit data patterns and parameter setting issues. We define a novel "Local Distance-based Outlier Factor" (LDOF) to measure the {outlier-ness} of objects in scattered datasets which addresses these issues. LDOF uses the relative location of an object to its neighbours to determine the degree to which the object deviates from its neighbourhood. Properties of LDOF are theoretically analysed including LDOF's lower bound and its false-detection probability, as well as parameter settings. In order to facilitate parameter settings in real-world applications, we employ a top-n technique in our outlier detection approach, where only the objects with the highest LDOF values are regarded as outliers. Compared to conventional approaches (such as top-n KNN and top-n LOF), our method top-n LDOF is more effective at detecting outliers in scattered data. It is also easier to set parameters, since its performance is relatively stable over a large range of parameter values, as illustrated by experimental results on both real-world and synthetic datasets.
[ { "version": "v1", "created": "Wed, 18 Mar 2009 23:50:29 GMT" } ]
2009-12-30T00:00:00
[ [ "Zhang", "Ke", "" ], [ "Hutter", "Marcus", "" ], [ "Jin", "Huidong", "" ] ]
TITLE: A New Local Distance-Based Outlier Detection Approach for Scattered Real-World Data ABSTRACT: Detecting outliers which are grossly different from or inconsistent with the remaining dataset is a major challenge in real-world KDD applications. Existing outlier detection methods are ineffective on scattered real-world datasets due to implicit data patterns and parameter setting issues. We define a novel "Local Distance-based Outlier Factor" (LDOF) to measure the {outlier-ness} of objects in scattered datasets which addresses these issues. LDOF uses the relative location of an object to its neighbours to determine the degree to which the object deviates from its neighbourhood. Properties of LDOF are theoretically analysed including LDOF's lower bound and its false-detection probability, as well as parameter settings. In order to facilitate parameter settings in real-world applications, we employ a top-n technique in our outlier detection approach, where only the objects with the highest LDOF values are regarded as outliers. Compared to conventional approaches (such as top-n KNN and top-n LOF), our method top-n LDOF is more effective at detecting outliers in scattered data. It is also easier to set parameters, since its performance is relatively stable over a large range of parameter values, as illustrated by experimental results on both real-world and synthetic datasets.
no_new_dataset
0.951729
0912.3982
William Jackson
D. Bhanu, S. Pavai Madeshwari
Retail Market analysis in targeting sales based on Consumer Behaviour using Fuzzy Clustering - A Rule Based Mode
null
Journal of Computing, Volume 1, Issue 1, pp 92-99, December 2009
null
null
cs.OH
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Product Bundling and offering products to customers is of critical importance in retail marketing. In general, product bundling and offering products to customers involves two main issues, namely identification of product taste according to demography and product evaluation and selection to increase sales. The former helps to identify, analyze and understand customer needs according to the demo-graphical characteristics and correspondingly transform them into a set of specifications and offerings for people. The latter, concerns with how to determine the best product strategy and offerings for the customer in helping the retail market to improve their sales. Existing research has focused only on identifying patterns for a particular dataset and for a particular setting. This work aims to develop an explicit decision support for the retailers to improve their product segmentation for different settings based on the people characteristics and thereby promoting sales by efficient knowledge discovery from the existing sales and product records. The work presents a framework, which models an association relation mapping between the customers and the clusters of products they purchase in an existing location and helps in finding rules for a new location. The methodology is based on the integration of popular data mining approaches such as clustering and association rule mining. It focuses on the discovery of rules that vary according to the economic and demographic characteristics and concentrates on marketing of products based on the population.
[ { "version": "v1", "created": "Sun, 20 Dec 2009 05:18:57 GMT" } ]
2009-12-22T00:00:00
[ [ "Bhanu", "D.", "" ], [ "Madeshwari", "S. Pavai", "" ] ]
TITLE: Retail Market analysis in targeting sales based on Consumer Behaviour using Fuzzy Clustering - A Rule Based Mode ABSTRACT: Product Bundling and offering products to customers is of critical importance in retail marketing. In general, product bundling and offering products to customers involves two main issues, namely identification of product taste according to demography and product evaluation and selection to increase sales. The former helps to identify, analyze and understand customer needs according to the demo-graphical characteristics and correspondingly transform them into a set of specifications and offerings for people. The latter, concerns with how to determine the best product strategy and offerings for the customer in helping the retail market to improve their sales. Existing research has focused only on identifying patterns for a particular dataset and for a particular setting. This work aims to develop an explicit decision support for the retailers to improve their product segmentation for different settings based on the people characteristics and thereby promoting sales by efficient knowledge discovery from the existing sales and product records. The work presents a framework, which models an association relation mapping between the customers and the clusters of products they purchase in an existing location and helps in finding rules for a new location. The methodology is based on the integration of popular data mining approaches such as clustering and association rule mining. It focuses on the discovery of rules that vary according to the economic and demographic characteristics and concentrates on marketing of products based on the population.
no_new_dataset
0.94801
0912.4141
Felix Moya-Anegon Dr
Borja Gonzalez-Pereira (1), Vicente Guerrero-Bote (1) and Felix Moya-Anegon (2) ((1) University of Extremadura, Department of Information and Communication, Scimago Group, Spain (2) CSIC, CCHS, IPP, Scimago Group Spain)
The SJR indicator: A new indicator of journals' scientific prestige
21 pages with graphs and tables
null
null
null
cs.DL physics.soc-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper proposes an indicator of journals' scientific prestige, the SJR indicator, for ranking scholarly journals based on citation weighting schemes and eigenvector centrality to be used in complex and heterogeneous citation networks such Scopus. Its computation methodology is described and the results after implementing the indicator over Scopus 2007 dataset are compared to an ad-hoc Journal Impact Factor both generally and inside specific scientific areas. The results showed that SJR indicator and JIF distributions fitted well to a power law distribution and that both metrics were strongly correlated, although there were also major changes in rank. There was an observable general trend that might indicate that SJR indicator values decreased certain JIF values whose citedeness was greater than would correspond to their scientific influence.
[ { "version": "v1", "created": "Mon, 21 Dec 2009 11:32:08 GMT" } ]
2009-12-22T00:00:00
[ [ "Gonzalez-Pereira", "Borja", "" ], [ "Guerrero-Bote", "Vicente", "" ], [ "Moya-Anegon", "Felix", "" ] ]
TITLE: The SJR indicator: A new indicator of journals' scientific prestige ABSTRACT: This paper proposes an indicator of journals' scientific prestige, the SJR indicator, for ranking scholarly journals based on citation weighting schemes and eigenvector centrality to be used in complex and heterogeneous citation networks such Scopus. Its computation methodology is described and the results after implementing the indicator over Scopus 2007 dataset are compared to an ad-hoc Journal Impact Factor both generally and inside specific scientific areas. The results showed that SJR indicator and JIF distributions fitted well to a power law distribution and that both metrics were strongly correlated, although there were also major changes in rank. There was an observable general trend that might indicate that SJR indicator values decreased certain JIF values whose citedeness was greater than would correspond to their scientific influence.
no_new_dataset
0.945349
0912.2430
Feng Xia
Feng Xia, Zhenzhen Xu, Lin Yao, Weifeng Sun, Mingchu Li
Prediction-Based Data Transmission for Energy Conservation in Wireless Body Sensors
To appear in The Int Workshop on Ubiquitous Body Sensor Networks (UBSN), in conjunction with the 5th Annual Int Wireless Internet Conf (WICON), Singapore, March 2010
null
null
null
cs.NI cs.DC
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Wireless body sensors are becoming popular in healthcare applications. Since they are either worn or implanted into human body, these sensors must be very small in size and light in weight. The energy consequently becomes an extremely scarce resource, and energy conservation turns into a first class design issue for body sensor networks (BSNs). This paper deals with this issue by taking into account the unique characteristics of BSNs in contrast to conventional wireless sensor networks (WSNs) for e.g. environment monitoring. A prediction-based data transmission approach suitable for BSNs is presented, which combines a dual prediction framework and a low-complexity prediction algorithm that takes advantage of PID (proportional-integral-derivative) control. Both the framework and the algorithm are generic, making the proposed approach widely applicable. The effectiveness of the approach is verified through simulations using real-world health monitoring datasets.
[ { "version": "v1", "created": "Sat, 12 Dec 2009 16:30:14 GMT" } ]
2009-12-15T00:00:00
[ [ "Xia", "Feng", "" ], [ "Xu", "Zhenzhen", "" ], [ "Yao", "Lin", "" ], [ "Sun", "Weifeng", "" ], [ "Li", "Mingchu", "" ] ]
TITLE: Prediction-Based Data Transmission for Energy Conservation in Wireless Body Sensors ABSTRACT: Wireless body sensors are becoming popular in healthcare applications. Since they are either worn or implanted into human body, these sensors must be very small in size and light in weight. The energy consequently becomes an extremely scarce resource, and energy conservation turns into a first class design issue for body sensor networks (BSNs). This paper deals with this issue by taking into account the unique characteristics of BSNs in contrast to conventional wireless sensor networks (WSNs) for e.g. environment monitoring. A prediction-based data transmission approach suitable for BSNs is presented, which combines a dual prediction framework and a low-complexity prediction algorithm that takes advantage of PID (proportional-integral-derivative) control. Both the framework and the algorithm are generic, making the proposed approach widely applicable. The effectiveness of the approach is verified through simulations using real-world health monitoring datasets.
no_new_dataset
0.955236
0912.0955
Rdv Ijcsis
Nazmeen Bibi Boodoo, and R. K. Subramanian
Robust Multi biometric Recognition Using Face and Ear Images
6 pages IEEE format, International Journal of Computer Science and Information Security, IJCSIS November 2009, ISSN 1947 5500, http://sites.google.com/site/ijcsis/
International Journal of Computer Science and Information Security, IJCSIS, Vol. 6, No. 2, pp. 164-169, November 2009, USA
null
ISSN 1947 5500
cs.CR cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This study investigates the use of ear as a biometric for authentication and shows experimental results obtained on a newly created dataset of 420 images. Images are passed to a quality module in order to reduce False Rejection Rate. The Principal Component Analysis (eigen ear) approach was used, obtaining 90.7 percent recognition rate. Improvement in recognition results is obtained when ear biometric is fused with face biometric. The fusion is done at decision level, achieving a recognition rate of 96 percent.
[ { "version": "v1", "created": "Fri, 4 Dec 2009 21:51:03 GMT" } ]
2009-12-08T00:00:00
[ [ "Boodoo", "Nazmeen Bibi", "" ], [ "Subramanian", "R. K.", "" ] ]
TITLE: Robust Multi biometric Recognition Using Face and Ear Images ABSTRACT: This study investigates the use of ear as a biometric for authentication and shows experimental results obtained on a newly created dataset of 420 images. Images are passed to a quality module in order to reduce False Rejection Rate. The Principal Component Analysis (eigen ear) approach was used, obtaining 90.7 percent recognition rate. Improvement in recognition results is obtained when ear biometric is fused with face biometric. The fusion is done at decision level, achieving a recognition rate of 96 percent.
new_dataset
0.953579
0912.1014
Rdv Ijcsis
Shailendra Singh, Sanjay Silakari
An ensemble approach for feature selection of Cyber Attack Dataset
6 pages IEEE format, International Journal of Computer Science and Information Security, IJCSIS November 2009, ISSN 1947 5500, http://sites.google.com/site/ijcsis/
International Journal of Computer Science and Information Security, IJCSIS, Vol. 6, No. 2, pp. 297-302, November 2009, USA
null
ISSN 1947 5500
cs.CR cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Feature selection is an indispensable preprocessing step when mining huge datasets that can significantly improve the overall system performance. Therefore in this paper we focus on a hybrid approach of feature selection. This method falls into two phases. The filter phase select the features with highest information gain and guides the initialization of search process for wrapper phase whose output the final feature subset. The final feature subsets are passed through the Knearest neighbor classifier for classification of attacks. The effectiveness of this algorithm is demonstrated on DARPA KDDCUP99 cyber attack dataset.
[ { "version": "v1", "created": "Sat, 5 Dec 2009 13:15:08 GMT" } ]
2009-12-08T00:00:00
[ [ "Singh", "Shailendra", "" ], [ "Silakari", "Sanjay", "" ] ]
TITLE: An ensemble approach for feature selection of Cyber Attack Dataset ABSTRACT: Feature selection is an indispensable preprocessing step when mining huge datasets that can significantly improve the overall system performance. Therefore in this paper we focus on a hybrid approach of feature selection. This method falls into two phases. The filter phase select the features with highest information gain and guides the initialization of search process for wrapper phase whose output the final feature subset. The final feature subsets are passed through the Knearest neighbor classifier for classification of attacks. The effectiveness of this algorithm is demonstrated on DARPA KDDCUP99 cyber attack dataset.
no_new_dataset
0.948442
0912.0717
Karol Gregor
Karol Gregor, Gregory Griffin
Behavior and performance of the deep belief networks on image classification
8 pages, 9 figures
null
null
null
cs.NE cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We apply deep belief networks of restricted Boltzmann machines to bags of words of sift features obtained from databases of 13 Scenes, 15 Scenes and Caltech 256 and study experimentally their behavior and performance. We find that the final performance in the supervised phase is reached much faster if the system is pre-trained. Pre-training the system on a larger dataset keeping the supervised dataset fixed improves the performance (for the 13 Scenes case). After the unsupervised pre-training, neurons arise that form approximate explicit representations for several categories (meaning they are mostly active for this category). The last three facts suggest that unsupervised training really discovers structure in these data. Pre-training can be done on a completely different dataset (we use Corel dataset) and we find that the supervised phase performs just as good (on the 15 Scenes dataset). This leads us to conjecture that one can pre-train the system once (e.g. in a factory) and subsequently apply it to many supervised problems which then learn much faster. The best performance is obtained with single hidden layer system suggesting that the histogram of sift features doesn't have much high level structure. The overall performance is almost equal, but slightly worse then that of the support vector machine and the spatial pyramidal matching.
[ { "version": "v1", "created": "Thu, 3 Dec 2009 19:20:14 GMT" } ]
2009-12-04T00:00:00
[ [ "Gregor", "Karol", "" ], [ "Griffin", "Gregory", "" ] ]
TITLE: Behavior and performance of the deep belief networks on image classification ABSTRACT: We apply deep belief networks of restricted Boltzmann machines to bags of words of sift features obtained from databases of 13 Scenes, 15 Scenes and Caltech 256 and study experimentally their behavior and performance. We find that the final performance in the supervised phase is reached much faster if the system is pre-trained. Pre-training the system on a larger dataset keeping the supervised dataset fixed improves the performance (for the 13 Scenes case). After the unsupervised pre-training, neurons arise that form approximate explicit representations for several categories (meaning they are mostly active for this category). The last three facts suggest that unsupervised training really discovers structure in these data. Pre-training can be done on a completely different dataset (we use Corel dataset) and we find that the supervised phase performs just as good (on the 15 Scenes dataset). This leads us to conjecture that one can pre-train the system once (e.g. in a factory) and subsequently apply it to many supervised problems which then learn much faster. The best performance is obtained with single hidden layer system suggesting that the histogram of sift features doesn't have much high level structure. The overall performance is almost equal, but slightly worse then that of the support vector machine and the spatial pyramidal matching.
no_new_dataset
0.947914
0903.2870
Patrick Erik Bradley
Patrick Erik Bradley
On $p$-adic Classification
16 pages, 7 figures, 1 table; added reference, corrected typos, minor content changes
p-Adic Numbers, Ultrametric Analysis, and Applications, Vol. 1, No. 4 (2009), 271-285
10.1134/S2070046609040013
null
cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A $p$-adic modification of the split-LBG classification method is presented in which first clusterings and then cluster centers are computed which locally minimise an energy function. The outcome for a fixed dataset is independent of the prime number $p$ with finitely many exceptions. The methods are applied to the construction of $p$-adic classifiers in the context of learning.
[ { "version": "v1", "created": "Mon, 16 Mar 2009 22:52:06 GMT" }, { "version": "v2", "created": "Wed, 24 Jun 2009 14:10:45 GMT" } ]
2009-12-01T00:00:00
[ [ "Bradley", "Patrick Erik", "" ] ]
TITLE: On $p$-adic Classification ABSTRACT: A $p$-adic modification of the split-LBG classification method is presented in which first clusterings and then cluster centers are computed which locally minimise an energy function. The outcome for a fixed dataset is independent of the prime number $p$ with finitely many exceptions. The methods are applied to the construction of $p$-adic classifiers in the context of learning.
no_new_dataset
0.949482
0712.2063
Vladimir Pestov
Vladimir Pestov
An axiomatic approach to intrinsic dimension of a dataset
10 pages, 5 figures, latex 2e with Elsevier macros, final submission to Neural Networks with referees' comments taken into account
Neural Networks 21, 2-3 (2008), 204-213.
null
null
cs.IR
null
We perform a deeper analysis of an axiomatic approach to the concept of intrinsic dimension of a dataset proposed by us in the IJCNN'07 paper (arXiv:cs/0703125). The main features of our approach are that a high intrinsic dimension of a dataset reflects the presence of the curse of dimensionality (in a certain mathematically precise sense), and that dimension of a discrete i.i.d. sample of a low-dimensional manifold is, with high probability, close to that of the manifold. At the same time, the intrinsic dimension of a sample is easily corrupted by moderate high-dimensional noise (of the same amplitude as the size of the manifold) and suffers from prohibitevely high computational complexity (computing it is an $NP$-complete problem). We outline a possible way to overcome these difficulties.
[ { "version": "v1", "created": "Wed, 12 Dec 2007 23:39:21 GMT" } ]
2009-11-17T00:00:00
[ [ "Pestov", "Vladimir", "" ] ]
TITLE: An axiomatic approach to intrinsic dimension of a dataset ABSTRACT: We perform a deeper analysis of an axiomatic approach to the concept of intrinsic dimension of a dataset proposed by us in the IJCNN'07 paper (arXiv:cs/0703125). The main features of our approach are that a high intrinsic dimension of a dataset reflects the presence of the curse of dimensionality (in a certain mathematically precise sense), and that dimension of a discrete i.i.d. sample of a low-dimensional manifold is, with high probability, close to that of the manifold. At the same time, the intrinsic dimension of a sample is easily corrupted by moderate high-dimensional noise (of the same amplitude as the size of the manifold) and suffers from prohibitevely high computational complexity (computing it is an $NP$-complete problem). We outline a possible way to overcome these difficulties.
no_new_dataset
0.94545
cs/9901004
Vladimir Pestov
Vladimir Pestov
On the geometry of similarity search: dimensionality curse and concentration of measure
7 pages, LaTeX 2e
Information Processing Letters 73 (2000), 47-51.
null
RP-99-01, Victoria University of Wellington, NZ
cs.IR cs.CG cs.DB cs.DS
null
We suggest that the curse of dimensionality affecting the similarity-based search in large datasets is a manifestation of the phenomenon of concentration of measure on high-dimensional structures. We prove that, under certain geometric assumptions on the query domain $\Omega$ and the dataset $X$, if $\Omega$ satisfies the so-called concentration property, then for most query points $x^\ast$ the ball of radius $(1+\e)d_X(x^\ast)$ centred at $x^\ast$ contains either all points of $X$ or else at least $C_1\exp(-C_2\e^2n)$ of them. Here $d_X(x^\ast)$ is the distance from $x^\ast$ to the nearest neighbour in $X$ and $n$ is the dimension of $\Omega$.
[ { "version": "v1", "created": "Tue, 12 Jan 1999 21:56:39 GMT" } ]
2009-11-17T00:00:00
[ [ "Pestov", "Vladimir", "" ] ]
TITLE: On the geometry of similarity search: dimensionality curse and concentration of measure ABSTRACT: We suggest that the curse of dimensionality affecting the similarity-based search in large datasets is a manifestation of the phenomenon of concentration of measure on high-dimensional structures. We prove that, under certain geometric assumptions on the query domain $\Omega$ and the dataset $X$, if $\Omega$ satisfies the so-called concentration property, then for most query points $x^\ast$ the ball of radius $(1+\e)d_X(x^\ast)$ centred at $x^\ast$ contains either all points of $X$ or else at least $C_1\exp(-C_2\e^2n)$ of them. Here $d_X(x^\ast)$ is the distance from $x^\ast$ to the nearest neighbour in $X$ and $n$ is the dimension of $\Omega$.
no_new_dataset
0.944125