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1508.03755
Team Lear
Danila Potapov (LEAR), Matthijs Douze (LEAR), Jerome Revaud (LEAR), Zaid Harchaoui (LEAR, CIMS), Cordelia Schmid (LEAR)
Beat-Event Detection in Action Movie Franchises
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
While important advances were recently made towards temporally localizing and recognizing specific human actions or activities in videos, efficient detection and classification of long video chunks belonging to semantically defined categories such as "pursuit" or "romance" remains challenging.We introduce a new dataset, Action Movie Franchises, consisting of a collection of Hollywood action movie franchises. We define 11 non-exclusive semantic categories - called beat-categories - that are broad enough to cover most of the movie footage. The corresponding beat-events are annotated as groups of video shots, possibly overlapping.We propose an approach for localizing beat-events based on classifying shots into beat-categories and learning the temporal constraints between shots. We show that temporal constraints significantly improve the classification performance. We set up an evaluation protocol for beat-event localization as well as for shot classification, depending on whether movies from the same franchise are present or not in the training data.
[ { "version": "v1", "created": "Sat, 15 Aug 2015 17:04:50 GMT" } ]
2015-08-18T00:00:00
[ [ "Potapov", "Danila", "", "LEAR" ], [ "Douze", "Matthijs", "", "LEAR" ], [ "Revaud", "Jerome", "", "LEAR" ], [ "Harchaoui", "Zaid", "", "LEAR, CIMS" ], [ "Schmid", "Cordelia", "", "LEAR" ] ]
TITLE: Beat-Event Detection in Action Movie Franchises ABSTRACT: While important advances were recently made towards temporally localizing and recognizing specific human actions or activities in videos, efficient detection and classification of long video chunks belonging to semantically defined categories such as "pursuit" or "romance" remains challenging.We introduce a new dataset, Action Movie Franchises, consisting of a collection of Hollywood action movie franchises. We define 11 non-exclusive semantic categories - called beat-categories - that are broad enough to cover most of the movie footage. The corresponding beat-events are annotated as groups of video shots, possibly overlapping.We propose an approach for localizing beat-events based on classifying shots into beat-categories and learning the temporal constraints between shots. We show that temporal constraints significantly improve the classification performance. We set up an evaluation protocol for beat-event localization as well as for shot classification, depending on whether movies from the same franchise are present or not in the training data.
new_dataset
0.957675
1508.03826
Shaohua Li
Shaohua Li, Jun Zhu, Chunyan Miao
A Generative Word Embedding Model and its Low Rank Positive Semidefinite Solution
Proceedings of the Conference on Empirical Methods in Natural Language Processing (EMNLP) 2015 2015, 11 pages, 2 figures
null
null
null
cs.CL cs.LG stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Most existing word embedding methods can be categorized into Neural Embedding Models and Matrix Factorization (MF)-based methods. However some models are opaque to probabilistic interpretation, and MF-based methods, typically solved using Singular Value Decomposition (SVD), may incur loss of corpus information. In addition, it is desirable to incorporate global latent factors, such as topics, sentiments or writing styles, into the word embedding model. Since generative models provide a principled way to incorporate latent factors, we propose a generative word embedding model, which is easy to interpret, and can serve as a basis of more sophisticated latent factor models. The model inference reduces to a low rank weighted positive semidefinite approximation problem. Its optimization is approached by eigendecomposition on a submatrix, followed by online blockwise regression, which is scalable and avoids the information loss in SVD. In experiments on 7 common benchmark datasets, our vectors are competitive to word2vec, and better than other MF-based methods.
[ { "version": "v1", "created": "Sun, 16 Aug 2015 14:12:17 GMT" } ]
2015-08-18T00:00:00
[ [ "Li", "Shaohua", "" ], [ "Zhu", "Jun", "" ], [ "Miao", "Chunyan", "" ] ]
TITLE: A Generative Word Embedding Model and its Low Rank Positive Semidefinite Solution ABSTRACT: Most existing word embedding methods can be categorized into Neural Embedding Models and Matrix Factorization (MF)-based methods. However some models are opaque to probabilistic interpretation, and MF-based methods, typically solved using Singular Value Decomposition (SVD), may incur loss of corpus information. In addition, it is desirable to incorporate global latent factors, such as topics, sentiments or writing styles, into the word embedding model. Since generative models provide a principled way to incorporate latent factors, we propose a generative word embedding model, which is easy to interpret, and can serve as a basis of more sophisticated latent factor models. The model inference reduces to a low rank weighted positive semidefinite approximation problem. Its optimization is approached by eigendecomposition on a submatrix, followed by online blockwise regression, which is scalable and avoids the information loss in SVD. In experiments on 7 common benchmark datasets, our vectors are competitive to word2vec, and better than other MF-based methods.
no_new_dataset
0.942242
1508.03928
Hongyang Li
Hongyang Li, Huchuan Lu, Zhe Lin, Xiaohui Shen, Brian Price
LCNN: Low-level Feature Embedded CNN for Salient Object Detection
null
null
null
null
cs.CV
http://creativecommons.org/licenses/by-nc-sa/4.0/
In this paper, we propose a novel deep neural network framework embedded with low-level features (LCNN) for salient object detection in complex images. We utilise the advantage of convolutional neural networks to automatically learn the high-level features that capture the structured information and semantic context in the image. In order to better adapt a CNN model into the saliency task, we redesign the network architecture based on the small-scale datasets. Several low-level features are extracted, which can effectively capture contrast and spatial information in the salient regions, and incorporated to compensate with the learned high-level features at the output of the last fully connected layer. The concatenated feature vector is further fed into a hinge-loss SVM detector in a joint discriminative learning manner and the final saliency score of each region within the bounding box is obtained by the linear combination of the detector's weights. Experiments on three challenging benchmark (MSRA-5000, PASCAL-S, ECCSD) demonstrate our algorithm to be effective and superior than most low-level oriented state-of-the-arts in terms of P-R curves, F-measure and mean absolute errors.
[ { "version": "v1", "created": "Mon, 17 Aug 2015 05:45:12 GMT" } ]
2015-08-18T00:00:00
[ [ "Li", "Hongyang", "" ], [ "Lu", "Huchuan", "" ], [ "Lin", "Zhe", "" ], [ "Shen", "Xiaohui", "" ], [ "Price", "Brian", "" ] ]
TITLE: LCNN: Low-level Feature Embedded CNN for Salient Object Detection ABSTRACT: In this paper, we propose a novel deep neural network framework embedded with low-level features (LCNN) for salient object detection in complex images. We utilise the advantage of convolutional neural networks to automatically learn the high-level features that capture the structured information and semantic context in the image. In order to better adapt a CNN model into the saliency task, we redesign the network architecture based on the small-scale datasets. Several low-level features are extracted, which can effectively capture contrast and spatial information in the salient regions, and incorporated to compensate with the learned high-level features at the output of the last fully connected layer. The concatenated feature vector is further fed into a hinge-loss SVM detector in a joint discriminative learning manner and the final saliency score of each region within the bounding box is obtained by the linear combination of the detector's weights. Experiments on three challenging benchmark (MSRA-5000, PASCAL-S, ECCSD) demonstrate our algorithm to be effective and superior than most low-level oriented state-of-the-arts in terms of P-R curves, F-measure and mean absolute errors.
no_new_dataset
0.947914
1508.03953
Tam Nguyen
Kang Wang, Tam V. Nguyen, Jiashi Feng, Jose Sepulveda
Sense Beyond Expressions: Cuteness
4 pages
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
With the development of Internet culture, cuteness has become a popular concept. Many people are curious about what factors making a person look cute. However, there is rare research to answer this interesting question. In this work, we construct a dataset of personal images with comprehensively annotated cuteness scores and facial attributes to investigate this high-level concept in depth. Based on this dataset, through an automatic attributes mining process, we find several critical attributes determining the cuteness of a person. We also develop a novel Continuous Latent Support Vector Machine (C-LSVM) method to predict the cuteness score of one person given only his image. Extensive evaluations validate the effectiveness of the proposed method for cuteness prediction.
[ { "version": "v1", "created": "Mon, 17 Aug 2015 08:48:54 GMT" } ]
2015-08-18T00:00:00
[ [ "Wang", "Kang", "" ], [ "Nguyen", "Tam V.", "" ], [ "Feng", "Jiashi", "" ], [ "Sepulveda", "Jose", "" ] ]
TITLE: Sense Beyond Expressions: Cuteness ABSTRACT: With the development of Internet culture, cuteness has become a popular concept. Many people are curious about what factors making a person look cute. However, there is rare research to answer this interesting question. In this work, we construct a dataset of personal images with comprehensively annotated cuteness scores and facial attributes to investigate this high-level concept in depth. Based on this dataset, through an automatic attributes mining process, we find several critical attributes determining the cuteness of a person. We also develop a novel Continuous Latent Support Vector Machine (C-LSVM) method to predict the cuteness score of one person given only his image. Extensive evaluations validate the effectiveness of the proposed method for cuteness prediction.
new_dataset
0.957118
1508.03975
Rossi Kamal Mr
Rossi Kamal, Choonog Seon Hong, and Mi Jung Choi
Autonomic Resilient Internet-of-Things(IoT)Management
null
null
null
null
cs.NI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In Resilient IoT, the revenue of service provider is resilient to uncertain usage-contexts(e.g. emotion, environmental contexts) of Smart-device users. Hence, Autonomic Resilient IoT Management problem is decomposed into two subproblems, namely m-connectivity and k-dominance, such that m-alternations on revenue making process is resilient to users common interests, which might be depicted through k-1 alternations of usage-contexts. In this context, a greedy approximation scheme Bee is proposed, which resolves aforementioned sub-problems with five consecutive models, namely Maverick, Siren, Pigmy, Arkeo and Augeas, respectively. Theoretical analysis justifies the problem as NP-hard, combinatorial optimization problem, which is amenable to greedy approximation. Moreover, Bee lays out the theoretical foundation of Resilient Fact-finding, followed by theoretical and experimental(i.e synthetic) proof, which show how Bee-resilience resolves acute CDS measurement problem. Accordingly, experiments on real Social rumor dataset extract dominator and dominate to justify how Bee resilience improves CDS measurement. Finally, case-study and prototype development are performed on Android and Web platforms in a Resilient IoT scenario, where service provider recommends personalized services for Smart-device users.
[ { "version": "v1", "created": "Mon, 17 Aug 2015 10:59:16 GMT" } ]
2015-08-18T00:00:00
[ [ "Kamal", "Rossi", "" ], [ "Hong", "Choonog Seon", "" ], [ "Choi", "Mi Jung", "" ] ]
TITLE: Autonomic Resilient Internet-of-Things(IoT)Management ABSTRACT: In Resilient IoT, the revenue of service provider is resilient to uncertain usage-contexts(e.g. emotion, environmental contexts) of Smart-device users. Hence, Autonomic Resilient IoT Management problem is decomposed into two subproblems, namely m-connectivity and k-dominance, such that m-alternations on revenue making process is resilient to users common interests, which might be depicted through k-1 alternations of usage-contexts. In this context, a greedy approximation scheme Bee is proposed, which resolves aforementioned sub-problems with five consecutive models, namely Maverick, Siren, Pigmy, Arkeo and Augeas, respectively. Theoretical analysis justifies the problem as NP-hard, combinatorial optimization problem, which is amenable to greedy approximation. Moreover, Bee lays out the theoretical foundation of Resilient Fact-finding, followed by theoretical and experimental(i.e synthetic) proof, which show how Bee-resilience resolves acute CDS measurement problem. Accordingly, experiments on real Social rumor dataset extract dominator and dominate to justify how Bee resilience improves CDS measurement. Finally, case-study and prototype development are performed on Android and Web platforms in a Resilient IoT scenario, where service provider recommends personalized services for Smart-device users.
no_new_dataset
0.951774
1508.04073
Ali Mousavi
Ali Mousavi, Richard G. Baraniuk
An Information-Theoretic Measure of Dependency Among Variables in Large Datasets
null
null
null
null
cs.IT math.IT stat.ME
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The maximal information coefficient (MIC), which measures the amount of dependence between two variables, is able to detect both linear and non-linear associations. However, computational cost grows rapidly as a function of the dataset size. In this paper, we develop a computationally efficient approximation to the MIC that replaces its dynamic programming step with a much simpler technique based on the uniform partitioning of data grid. A variety of experiments demonstrate the quality of our approximation.
[ { "version": "v1", "created": "Mon, 17 Aug 2015 16:00:30 GMT" } ]
2015-08-18T00:00:00
[ [ "Mousavi", "Ali", "" ], [ "Baraniuk", "Richard G.", "" ] ]
TITLE: An Information-Theoretic Measure of Dependency Among Variables in Large Datasets ABSTRACT: The maximal information coefficient (MIC), which measures the amount of dependence between two variables, is able to detect both linear and non-linear associations. However, computational cost grows rapidly as a function of the dataset size. In this paper, we develop a computationally efficient approximation to the MIC that replaces its dynamic programming step with a much simpler technique based on the uniform partitioning of data grid. A variety of experiments demonstrate the quality of our approximation.
no_new_dataset
0.947039
1508.04123
Alex Mbaziira
Alex V. Mbaziira, Ehab Abozinadah, and James H. Jones Jr
Evaluating Classifiers in Detecting 419 Scams in Bilingual Cybercriminal Communities
7 pages
null
null
null
cs.SI cs.CY cs.LG
http://creativecommons.org/licenses/by/4.0/
Incidents of organized cybercrime are rising because of criminals are reaping high financial rewards while incurring low costs to commit crime. As the digital landscape broadens to accommodate more internet-enabled devices and technologies like social media, more cybercriminals who are not native English speakers are invading cyberspace to cash in on quick exploits. In this paper we evaluate the performance of three machine learning classifiers in detecting 419 scams in a bilingual Nigerian cybercriminal community. We use three popular classifiers in text processing namely: Na\"ive Bayes, k-nearest neighbors (IBK) and Support Vector Machines (SVM). The preliminary results on a real world dataset reveal the SVM significantly outperforms Na\"ive Bayes and IBK at 95% confidence level.
[ { "version": "v1", "created": "Mon, 17 Aug 2015 19:38:50 GMT" } ]
2015-08-18T00:00:00
[ [ "Mbaziira", "Alex V.", "" ], [ "Abozinadah", "Ehab", "" ], [ "Jones", "James H.", "Jr" ] ]
TITLE: Evaluating Classifiers in Detecting 419 Scams in Bilingual Cybercriminal Communities ABSTRACT: Incidents of organized cybercrime are rising because of criminals are reaping high financial rewards while incurring low costs to commit crime. As the digital landscape broadens to accommodate more internet-enabled devices and technologies like social media, more cybercriminals who are not native English speakers are invading cyberspace to cash in on quick exploits. In this paper we evaluate the performance of three machine learning classifiers in detecting 419 scams in a bilingual Nigerian cybercriminal community. We use three popular classifiers in text processing namely: Na\"ive Bayes, k-nearest neighbors (IBK) and Support Vector Machines (SVM). The preliminary results on a real world dataset reveal the SVM significantly outperforms Na\"ive Bayes and IBK at 95% confidence level.
no_new_dataset
0.95253
1508.03601
Sanjay Singh
Ranjitha R. K. and Sanjay Singh
Is Stack Overflow Overflowing With Questions and Tags
11 pages, 7 figures, 3 tables Presented at Third International Symposium on Women in Computing and Informatics (WCI-2015)
null
null
null
cs.SI cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Programming question and answer (Q & A) websites, such as Quora, Stack Overflow, and Yahoo! Answer etc. helps us to understand the programming concepts easily and quickly in a way that has been tested and applied by many software developers. Stack Overflow is one of the most frequently used programming Q\&A website where the questions and answers posted are presently analyzed manually, which requires a huge amount of time and resource. To save the effort, we present a topic modeling based technique to analyze the words of the original texts to discover the themes that run through them. We also propose a method to automate the process of reviewing the quality of questions on Stack Overflow dataset in order to avoid ballooning the stack overflow with insignificant questions. The proposed method also recommends the appropriate tags for the new post, which averts the creation of unnecessary tags on Stack Overflow.
[ { "version": "v1", "created": "Fri, 14 Aug 2015 18:39:18 GMT" } ]
2015-08-17T00:00:00
[ [ "K.", "Ranjitha R.", "" ], [ "Singh", "Sanjay", "" ] ]
TITLE: Is Stack Overflow Overflowing With Questions and Tags ABSTRACT: Programming question and answer (Q & A) websites, such as Quora, Stack Overflow, and Yahoo! Answer etc. helps us to understand the programming concepts easily and quickly in a way that has been tested and applied by many software developers. Stack Overflow is one of the most frequently used programming Q\&A website where the questions and answers posted are presently analyzed manually, which requires a huge amount of time and resource. To save the effort, we present a topic modeling based technique to analyze the words of the original texts to discover the themes that run through them. We also propose a method to automate the process of reviewing the quality of questions on Stack Overflow dataset in order to avoid ballooning the stack overflow with insignificant questions. The proposed method also recommends the appropriate tags for the new post, which averts the creation of unnecessary tags on Stack Overflow.
no_new_dataset
0.950641
1508.03116
Christan Grant
Christan Grant, Daisy Zhe Wang, Michael L. Wick
Query-Driven Sampling for Collective Entity Resolution
null
null
null
null
cs.DB
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Probabilistic databases play a preeminent role in the processing and management of uncertain data. Recently, many database research efforts have integrated probabilistic models into databases to support tasks such as information extraction and labeling. Many of these efforts are based on batch oriented inference which inhibits a realtime workflow. One important task is entity resolution (ER). ER is the process of determining records (mentions) in a database that correspond to the same real-world entity. Traditional pairwise ER methods can lead to inconsistencies and low accuracy due to localized decisions. Leading ER systems solve this problem by collectively resolving all records using a probabilistic graphical model and Markov chain Monte Carlo (MCMC) inference. However, for large datasets this is an extremely expensive process. One key observation is that, such exhaustive ER process incurs a huge up-front cost, which is wasteful in practice because most users are interested in only a small subset of entities. In this paper, we advocate pay-as-you-go entity resolution by developing a number of query-driven collective ER techniques. We introduce two classes of SQL queries that involve ER operators --- selection-driven ER and join-driven ER. We implement novel variations of the MCMC Metropolis Hastings algorithm to generate biased samples and selectivity-based scheduling algorithms to support the two classes of ER queries. Finally, we show that query-driven ER algorithms can converge and return results within minutes over a database populated with the extraction from a newswire dataset containing 71 million mentions.
[ { "version": "v1", "created": "Thu, 13 Aug 2015 04:23:58 GMT" } ]
2015-08-14T00:00:00
[ [ "Grant", "Christan", "" ], [ "Wang", "Daisy Zhe", "" ], [ "Wick", "Michael L.", "" ] ]
TITLE: Query-Driven Sampling for Collective Entity Resolution ABSTRACT: Probabilistic databases play a preeminent role in the processing and management of uncertain data. Recently, many database research efforts have integrated probabilistic models into databases to support tasks such as information extraction and labeling. Many of these efforts are based on batch oriented inference which inhibits a realtime workflow. One important task is entity resolution (ER). ER is the process of determining records (mentions) in a database that correspond to the same real-world entity. Traditional pairwise ER methods can lead to inconsistencies and low accuracy due to localized decisions. Leading ER systems solve this problem by collectively resolving all records using a probabilistic graphical model and Markov chain Monte Carlo (MCMC) inference. However, for large datasets this is an extremely expensive process. One key observation is that, such exhaustive ER process incurs a huge up-front cost, which is wasteful in practice because most users are interested in only a small subset of entities. In this paper, we advocate pay-as-you-go entity resolution by developing a number of query-driven collective ER techniques. We introduce two classes of SQL queries that involve ER operators --- selection-driven ER and join-driven ER. We implement novel variations of the MCMC Metropolis Hastings algorithm to generate biased samples and selectivity-based scheduling algorithms to support the two classes of ER queries. Finally, we show that query-driven ER algorithms can converge and return results within minutes over a database populated with the extraction from a newswire dataset containing 71 million mentions.
no_new_dataset
0.907926
1508.02968
Djamal Belazzougui
Djamal Belazzougui and Fabio Cunial
Space-efficient detection of unusual words
arXiv admin note: text overlap with arXiv:1502.06370
null
null
null
cs.DS
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Detecting all the strings that occur in a text more frequently or less frequently than expected according to an IID or a Markov model is a basic problem in string mining, yet current algorithms are based on data structures that are either space-inefficient or incur large slowdowns, and current implementations cannot scale to genomes or metagenomes in practice. In this paper we engineer an algorithm based on the suffix tree of a string to use just a small data structure built on the Burrows-Wheeler transform, and a stack of $O(\sigma^2\log^2 n)$ bits, where $n$ is the length of the string and $\sigma$ is the size of the alphabet. The size of the stack is $o(n)$ except for very large values of $\sigma$. We further improve the algorithm by removing its time dependency on $\sigma$, by reporting only a subset of the maximal repeats and of the minimal rare words of the string, and by detecting and scoring candidate under-represented strings that $\textit{do not occur}$ in the string. Our algorithms are practical and work directly on the BWT, thus they can be immediately applied to a number of existing datasets that are available in this form, returning this string mining problem to a manageable scale.
[ { "version": "v1", "created": "Wed, 12 Aug 2015 16:01:21 GMT" } ]
2015-08-13T00:00:00
[ [ "Belazzougui", "Djamal", "" ], [ "Cunial", "Fabio", "" ] ]
TITLE: Space-efficient detection of unusual words ABSTRACT: Detecting all the strings that occur in a text more frequently or less frequently than expected according to an IID or a Markov model is a basic problem in string mining, yet current algorithms are based on data structures that are either space-inefficient or incur large slowdowns, and current implementations cannot scale to genomes or metagenomes in practice. In this paper we engineer an algorithm based on the suffix tree of a string to use just a small data structure built on the Burrows-Wheeler transform, and a stack of $O(\sigma^2\log^2 n)$ bits, where $n$ is the length of the string and $\sigma$ is the size of the alphabet. The size of the stack is $o(n)$ except for very large values of $\sigma$. We further improve the algorithm by removing its time dependency on $\sigma$, by reporting only a subset of the maximal repeats and of the minimal rare words of the string, and by detecting and scoring candidate under-represented strings that $\textit{do not occur}$ in the string. Our algorithms are practical and work directly on the BWT, thus they can be immediately applied to a number of existing datasets that are available in this form, returning this string mining problem to a manageable scale.
no_new_dataset
0.943086
1503.04337
Yuekai Sun
Jason D. Lee, Yuekai Sun, Qiang Liu, Jonathan E. Taylor
Communication-efficient sparse regression: a one-shot approach
29 pages, 3 figures
null
null
null
stat.ML cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We devise a one-shot approach to distributed sparse regression in the high-dimensional setting. The key idea is to average "debiased" or "desparsified" lasso estimators. We show the approach converges at the same rate as the lasso as long as the dataset is not split across too many machines. We also extend the approach to generalized linear models.
[ { "version": "v1", "created": "Sat, 14 Mar 2015 19:43:30 GMT" }, { "version": "v2", "created": "Mon, 10 Aug 2015 13:57:12 GMT" }, { "version": "v3", "created": "Tue, 11 Aug 2015 17:16:01 GMT" } ]
2015-08-12T00:00:00
[ [ "Lee", "Jason D.", "" ], [ "Sun", "Yuekai", "" ], [ "Liu", "Qiang", "" ], [ "Taylor", "Jonathan E.", "" ] ]
TITLE: Communication-efficient sparse regression: a one-shot approach ABSTRACT: We devise a one-shot approach to distributed sparse regression in the high-dimensional setting. The key idea is to average "debiased" or "desparsified" lasso estimators. We show the approach converges at the same rate as the lasso as long as the dataset is not split across too many machines. We also extend the approach to generalized linear models.
no_new_dataset
0.948632
1505.01728
Yamuna Prasad
Yamuna Prasad, K. K. Biswas
Integrating K-means with Quadratic Programming Feature Selection
17 pages, 11 figures
null
null
null
cs.CV cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Several data mining problems are characterized by data in high dimensions. One of the popular ways to reduce the dimensionality of the data is to perform feature selection, i.e, select a subset of relevant and non-redundant features. Recently, Quadratic Programming Feature Selection (QPFS) has been proposed which formulates the feature selection problem as a quadratic program. It has been shown to outperform many of the existing feature selection methods for a variety of applications. Though, better than many existing approaches, the running time complexity of QPFS is cubic in the number of features, which can be quite computationally expensive even for moderately sized datasets. In this paper we propose a novel method for feature selection by integrating k-means clustering with QPFS. The basic variant of our approach runs k-means to bring down the number of features which need to be passed on to QPFS. We then enhance this idea, wherein we gradually refine the feature space from a very coarse clustering to a fine-grained one, by interleaving steps of QPFS with k-means clustering. Every step of QPFS helps in identifying the clusters of irrelevant features (which can then be thrown away), whereas every step of k-means further refines the clusters which are potentially relevant. We show that our iterative refinement of clusters is guaranteed to converge. We provide bounds on the number of distance computations involved in the k-means algorithm. Further, each QPFS run is now cubic in number of clusters, which can be much smaller than actual number of features. Experiments on eight publicly available datasets show that our approach gives significant computational gains (both in time and memory), over standard QPFS as well as other state of the art feature selection methods, even while improving the overall accuracy.
[ { "version": "v1", "created": "Thu, 7 May 2015 14:45:11 GMT" }, { "version": "v2", "created": "Tue, 11 Aug 2015 18:06:36 GMT" } ]
2015-08-12T00:00:00
[ [ "Prasad", "Yamuna", "" ], [ "Biswas", "K. K.", "" ] ]
TITLE: Integrating K-means with Quadratic Programming Feature Selection ABSTRACT: Several data mining problems are characterized by data in high dimensions. One of the popular ways to reduce the dimensionality of the data is to perform feature selection, i.e, select a subset of relevant and non-redundant features. Recently, Quadratic Programming Feature Selection (QPFS) has been proposed which formulates the feature selection problem as a quadratic program. It has been shown to outperform many of the existing feature selection methods for a variety of applications. Though, better than many existing approaches, the running time complexity of QPFS is cubic in the number of features, which can be quite computationally expensive even for moderately sized datasets. In this paper we propose a novel method for feature selection by integrating k-means clustering with QPFS. The basic variant of our approach runs k-means to bring down the number of features which need to be passed on to QPFS. We then enhance this idea, wherein we gradually refine the feature space from a very coarse clustering to a fine-grained one, by interleaving steps of QPFS with k-means clustering. Every step of QPFS helps in identifying the clusters of irrelevant features (which can then be thrown away), whereas every step of k-means further refines the clusters which are potentially relevant. We show that our iterative refinement of clusters is guaranteed to converge. We provide bounds on the number of distance computations involved in the k-means algorithm. Further, each QPFS run is now cubic in number of clusters, which can be much smaller than actual number of features. Experiments on eight publicly available datasets show that our approach gives significant computational gains (both in time and memory), over standard QPFS as well as other state of the art feature selection methods, even while improving the overall accuracy.
no_new_dataset
0.946597
1508.01951
Besmira Nushi
Besmira Nushi, Adish Singla, Anja Gruenheid, Erfan Zamanian, Andreas Krause, Donald Kossmann
Crowd Access Path Optimization: Diversity Matters
10 pages, 3rd AAAI Conference on Human Computation and Crowdsourcing (HCOMP 2015)
null
null
null
cs.LG cs.DB
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Quality assurance is one the most important challenges in crowdsourcing. Assigning tasks to several workers to increase quality through redundant answers can be expensive if asking homogeneous sources. This limitation has been overlooked by current crowdsourcing platforms resulting therefore in costly solutions. In order to achieve desirable cost-quality tradeoffs it is essential to apply efficient crowd access optimization techniques. Our work argues that optimization needs to be aware of diversity and correlation of information within groups of individuals so that crowdsourcing redundancy can be adequately planned beforehand. Based on this intuitive idea, we introduce the Access Path Model (APM), a novel crowd model that leverages the notion of access paths as an alternative way of retrieving information. APM aggregates answers ensuring high quality and meaningful confidence. Moreover, we devise a greedy optimization algorithm for this model that finds a provably good approximate plan to access the crowd. We evaluate our approach on three crowdsourced datasets that illustrate various aspects of the problem. Our results show that the Access Path Model combined with greedy optimization is cost-efficient and practical to overcome common difficulties in large-scale crowdsourcing like data sparsity and anonymity.
[ { "version": "v1", "created": "Sat, 8 Aug 2015 20:36:54 GMT" }, { "version": "v2", "created": "Tue, 11 Aug 2015 07:21:57 GMT" } ]
2015-08-12T00:00:00
[ [ "Nushi", "Besmira", "" ], [ "Singla", "Adish", "" ], [ "Gruenheid", "Anja", "" ], [ "Zamanian", "Erfan", "" ], [ "Krause", "Andreas", "" ], [ "Kossmann", "Donald", "" ] ]
TITLE: Crowd Access Path Optimization: Diversity Matters ABSTRACT: Quality assurance is one the most important challenges in crowdsourcing. Assigning tasks to several workers to increase quality through redundant answers can be expensive if asking homogeneous sources. This limitation has been overlooked by current crowdsourcing platforms resulting therefore in costly solutions. In order to achieve desirable cost-quality tradeoffs it is essential to apply efficient crowd access optimization techniques. Our work argues that optimization needs to be aware of diversity and correlation of information within groups of individuals so that crowdsourcing redundancy can be adequately planned beforehand. Based on this intuitive idea, we introduce the Access Path Model (APM), a novel crowd model that leverages the notion of access paths as an alternative way of retrieving information. APM aggregates answers ensuring high quality and meaningful confidence. Moreover, we devise a greedy optimization algorithm for this model that finds a provably good approximate plan to access the crowd. We evaluate our approach on three crowdsourced datasets that illustrate various aspects of the problem. Our results show that the Access Path Model combined with greedy optimization is cost-efficient and practical to overcome common difficulties in large-scale crowdsourcing like data sparsity and anonymity.
no_new_dataset
0.951188
1412.8293
Jiyan Yang
Haim Avron, Vikas Sindhwani, Jiyan Yang, Michael Mahoney
Quasi-Monte Carlo Feature Maps for Shift-Invariant Kernels
A short version of this paper has been presented in ICML 2014
null
null
null
stat.ML cs.LG math.NA stat.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the problem of improving the efficiency of randomized Fourier feature maps to accelerate training and testing speed of kernel methods on large datasets. These approximate feature maps arise as Monte Carlo approximations to integral representations of shift-invariant kernel functions (e.g., Gaussian kernel). In this paper, we propose to use Quasi-Monte Carlo (QMC) approximations instead, where the relevant integrands are evaluated on a low-discrepancy sequence of points as opposed to random point sets as in the Monte Carlo approach. We derive a new discrepancy measure called box discrepancy based on theoretical characterizations of the integration error with respect to a given sequence. We then propose to learn QMC sequences adapted to our setting based on explicit box discrepancy minimization. Our theoretical analyses are complemented with empirical results that demonstrate the effectiveness of classical and adaptive QMC techniques for this problem.
[ { "version": "v1", "created": "Mon, 29 Dec 2014 10:00:39 GMT" }, { "version": "v2", "created": "Sun, 9 Aug 2015 07:20:00 GMT" } ]
2015-08-11T00:00:00
[ [ "Avron", "Haim", "" ], [ "Sindhwani", "Vikas", "" ], [ "Yang", "Jiyan", "" ], [ "Mahoney", "Michael", "" ] ]
TITLE: Quasi-Monte Carlo Feature Maps for Shift-Invariant Kernels ABSTRACT: We consider the problem of improving the efficiency of randomized Fourier feature maps to accelerate training and testing speed of kernel methods on large datasets. These approximate feature maps arise as Monte Carlo approximations to integral representations of shift-invariant kernel functions (e.g., Gaussian kernel). In this paper, we propose to use Quasi-Monte Carlo (QMC) approximations instead, where the relevant integrands are evaluated on a low-discrepancy sequence of points as opposed to random point sets as in the Monte Carlo approach. We derive a new discrepancy measure called box discrepancy based on theoretical characterizations of the integration error with respect to a given sequence. We then propose to learn QMC sequences adapted to our setting based on explicit box discrepancy minimization. Our theoretical analyses are complemented with empirical results that demonstrate the effectiveness of classical and adaptive QMC techniques for this problem.
no_new_dataset
0.949949
1508.02050
Tahani Almanie
Tahani Almanie, Rsha Mirza and Elizabeth Lor
Crime Prediction Based On Crime Types And Using Spatial And Temporal Criminal Hotspots
19 pages, 18 figures, 7 tables
International Journal of Data Mining & Knowledge Management Process (IJDKP) Vol.5, No.4, July 2015
10.5121/ijdkp.2015.5401
null
cs.AI cs.CY cs.DB
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper focuses on finding spatial and temporal criminal hotspots. It analyses two different real-world crimes datasets for Denver, CO and Los Angeles, CA and provides a comparison between the two datasets through a statistical analysis supported by several graphs. Then, it clarifies how we conducted Apriori algorithm to produce interesting frequent patterns for criminal hotspots. In addition, the paper shows how we used Decision Tree classifier and Naive Bayesian classifier in order to predict potential crime types. To further analyse crimes datasets, the paper introduces an analysis study by combining our findings of Denver crimes dataset with its demographics information in order to capture the factors that might affect the safety of neighborhoods. The results of this solution could be used to raise awareness regarding the dangerous locations and to help agencies to predict future crimes in a specific location within a particular time.
[ { "version": "v1", "created": "Sun, 9 Aug 2015 17:15:56 GMT" } ]
2015-08-11T00:00:00
[ [ "Almanie", "Tahani", "" ], [ "Mirza", "Rsha", "" ], [ "Lor", "Elizabeth", "" ] ]
TITLE: Crime Prediction Based On Crime Types And Using Spatial And Temporal Criminal Hotspots ABSTRACT: This paper focuses on finding spatial and temporal criminal hotspots. It analyses two different real-world crimes datasets for Denver, CO and Los Angeles, CA and provides a comparison between the two datasets through a statistical analysis supported by several graphs. Then, it clarifies how we conducted Apriori algorithm to produce interesting frequent patterns for criminal hotspots. In addition, the paper shows how we used Decision Tree classifier and Naive Bayesian classifier in order to predict potential crime types. To further analyse crimes datasets, the paper introduces an analysis study by combining our findings of Denver crimes dataset with its demographics information in order to capture the factors that might affect the safety of neighborhoods. The results of this solution could be used to raise awareness regarding the dangerous locations and to help agencies to predict future crimes in a specific location within a particular time.
no_new_dataset
0.950641
1508.02086
Hassan Kingravi
Hassan A. Kingravi, Harshal Maske, Girish Chowdhary
Kernel Controllers: A Systems-Theoretic Approach for Data-Driven Modeling and Control of Spatiotemporally Evolving Processes
null
null
null
null
cs.SY
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the problem of modeling, estimating, and controlling the latent state of a spatiotemporally evolving continuous function using very few sensor measurements and actuator locations. Our solution to the problem consists of two parts: a predictive model of functional evolution, and feedback based estimator and controllers that can robustly recover the state of the model and drive it to a desired function. We show that layering a dynamical systems prior over temporal evolution of weights of a kernel model is a valid approach to spatiotemporal modeling that leads to systems theoretic, control-usable, predictive models. We provide sufficient conditions on the number of sensors and actuators required to guarantee observability and controllability. The approach is validated on a large real dataset, and in simulation for the control of spatiotemporally evolving function.
[ { "version": "v1", "created": "Sun, 9 Aug 2015 21:26:55 GMT" } ]
2015-08-11T00:00:00
[ [ "Kingravi", "Hassan A.", "" ], [ "Maske", "Harshal", "" ], [ "Chowdhary", "Girish", "" ] ]
TITLE: Kernel Controllers: A Systems-Theoretic Approach for Data-Driven Modeling and Control of Spatiotemporally Evolving Processes ABSTRACT: We consider the problem of modeling, estimating, and controlling the latent state of a spatiotemporally evolving continuous function using very few sensor measurements and actuator locations. Our solution to the problem consists of two parts: a predictive model of functional evolution, and feedback based estimator and controllers that can robustly recover the state of the model and drive it to a desired function. We show that layering a dynamical systems prior over temporal evolution of weights of a kernel model is a valid approach to spatiotemporal modeling that leads to systems theoretic, control-usable, predictive models. We provide sufficient conditions on the number of sensors and actuators required to guarantee observability and controllability. The approach is validated on a large real dataset, and in simulation for the control of spatiotemporally evolving function.
no_new_dataset
0.943919
1508.02091
Jack Hessel
Jack Hessel, Nicolas Savva, Michael J. Wilber
Image Representations and New Domains in Neural Image Captioning
11 Pages, 5 Images, To appear at EMNLP 2015's Vision + Learning workshop
null
null
null
cs.CL cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We examine the possibility that recent promising results in automatic caption generation are due primarily to language models. By varying image representation quality produced by a convolutional neural network, we find that a state-of-the-art neural captioning algorithm is able to produce quality captions even when provided with surprisingly poor image representations. We replicate this result in a new, fine-grained, transfer learned captioning domain, consisting of 66K recipe image/title pairs. We also provide some experiments regarding the appropriateness of datasets for automatic captioning, and find that having multiple captions per image is beneficial, but not an absolute requirement.
[ { "version": "v1", "created": "Sun, 9 Aug 2015 22:52:10 GMT" } ]
2015-08-11T00:00:00
[ [ "Hessel", "Jack", "" ], [ "Savva", "Nicolas", "" ], [ "Wilber", "Michael J.", "" ] ]
TITLE: Image Representations and New Domains in Neural Image Captioning ABSTRACT: We examine the possibility that recent promising results in automatic caption generation are due primarily to language models. By varying image representation quality produced by a convolutional neural network, we find that a state-of-the-art neural captioning algorithm is able to produce quality captions even when provided with surprisingly poor image representations. We replicate this result in a new, fine-grained, transfer learned captioning domain, consisting of 66K recipe image/title pairs. We also provide some experiments regarding the appropriateness of datasets for automatic captioning, and find that having multiple captions per image is beneficial, but not an absolute requirement.
no_new_dataset
0.948632
1508.02268
Ning Chen
Ning Chen and Jun Zhu and Jianfei Chen and Ting Chen
Dropout Training for SVMs with Data Augmentation
15 pages. arXiv admin note: substantial text overlap with arXiv:1404.4171
null
null
null
cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Dropout and other feature noising schemes have shown promising results in controlling over-fitting by artificially corrupting the training data. Though extensive theoretical and empirical studies have been performed for generalized linear models, little work has been done for support vector machines (SVMs), one of the most successful approaches for supervised learning. This paper presents dropout training for both linear SVMs and the nonlinear extension with latent representation learning. For linear SVMs, to deal with the intractable expectation of the non-smooth hinge loss under corrupting distributions, we develop an iteratively re-weighted least square (IRLS) algorithm by exploring data augmentation techniques. Our algorithm iteratively minimizes the expectation of a re-weighted least square problem, where the re-weights are analytically updated. For nonlinear latent SVMs, we consider learning one layer of latent representations in SVMs and extend the data augmentation technique in conjunction with first-order Taylor-expansion to deal with the intractable expected non-smooth hinge loss and the nonlinearity of latent representations. Finally, we apply the similar data augmentation ideas to develop a new IRLS algorithm for the expected logistic loss under corrupting distributions, and we further develop a non-linear extension of logistic regression by incorporating one layer of latent representations. Our algorithms offer insights on the connection and difference between the hinge loss and logistic loss in dropout training. Empirical results on several real datasets demonstrate the effectiveness of dropout training on significantly boosting the classification accuracy of both linear and nonlinear SVMs. In addition, the nonlinear SVMs further improve the prediction performance on several image datasets.
[ { "version": "v1", "created": "Mon, 10 Aug 2015 14:57:30 GMT" } ]
2015-08-11T00:00:00
[ [ "Chen", "Ning", "" ], [ "Zhu", "Jun", "" ], [ "Chen", "Jianfei", "" ], [ "Chen", "Ting", "" ] ]
TITLE: Dropout Training for SVMs with Data Augmentation ABSTRACT: Dropout and other feature noising schemes have shown promising results in controlling over-fitting by artificially corrupting the training data. Though extensive theoretical and empirical studies have been performed for generalized linear models, little work has been done for support vector machines (SVMs), one of the most successful approaches for supervised learning. This paper presents dropout training for both linear SVMs and the nonlinear extension with latent representation learning. For linear SVMs, to deal with the intractable expectation of the non-smooth hinge loss under corrupting distributions, we develop an iteratively re-weighted least square (IRLS) algorithm by exploring data augmentation techniques. Our algorithm iteratively minimizes the expectation of a re-weighted least square problem, where the re-weights are analytically updated. For nonlinear latent SVMs, we consider learning one layer of latent representations in SVMs and extend the data augmentation technique in conjunction with first-order Taylor-expansion to deal with the intractable expected non-smooth hinge loss and the nonlinearity of latent representations. Finally, we apply the similar data augmentation ideas to develop a new IRLS algorithm for the expected logistic loss under corrupting distributions, and we further develop a non-linear extension of logistic regression by incorporating one layer of latent representations. Our algorithms offer insights on the connection and difference between the hinge loss and logistic loss in dropout training. Empirical results on several real datasets demonstrate the effectiveness of dropout training on significantly boosting the classification accuracy of both linear and nonlinear SVMs. In addition, the nonlinear SVMs further improve the prediction performance on several image datasets.
no_new_dataset
0.952574
1508.01534
Jundong Liu
Bibo Shi, Jundong Liu
Nonlinear Metric Learning for kNN and SVMs through Geometric Transformations
null
null
null
null
cs.LG cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In recent years, research efforts to extend linear metric learning models to handle nonlinear structures have attracted great interests. In this paper, we propose a novel nonlinear solution through the utilization of deformable geometric models to learn spatially varying metrics, and apply the strategy to boost the performance of both kNN and SVM classifiers. Thin-plate splines (TPS) are chosen as the geometric model due to their remarkable versatility and representation power in accounting for high-order deformations. By transforming the input space through TPS, we can pull same-class neighbors closer while pushing different-class points farther away in kNN, as well as make the input data points more linearly separable in SVMs. Improvements in the performance of kNN classification are demonstrated through experiments on synthetic and real world datasets, with comparisons made with several state-of-the-art metric learning solutions. Our SVM-based models also achieve significant improvements over traditional linear and kernel SVMs with the same datasets.
[ { "version": "v1", "created": "Thu, 6 Aug 2015 20:29:28 GMT" } ]
2015-08-10T00:00:00
[ [ "Shi", "Bibo", "" ], [ "Liu", "Jundong", "" ] ]
TITLE: Nonlinear Metric Learning for kNN and SVMs through Geometric Transformations ABSTRACT: In recent years, research efforts to extend linear metric learning models to handle nonlinear structures have attracted great interests. In this paper, we propose a novel nonlinear solution through the utilization of deformable geometric models to learn spatially varying metrics, and apply the strategy to boost the performance of both kNN and SVM classifiers. Thin-plate splines (TPS) are chosen as the geometric model due to their remarkable versatility and representation power in accounting for high-order deformations. By transforming the input space through TPS, we can pull same-class neighbors closer while pushing different-class points farther away in kNN, as well as make the input data points more linearly separable in SVMs. Improvements in the performance of kNN classification are demonstrated through experiments on synthetic and real world datasets, with comparisons made with several state-of-the-art metric learning solutions. Our SVM-based models also achieve significant improvements over traditional linear and kernel SVMs with the same datasets.
no_new_dataset
0.954984
1508.01549
Uday Kamath Dr.
Uday Kamath, Carlotta Domeniconi and Kenneth De Jong
Theoretical and Empirical Analysis of a Parallel Boosting Algorithm
null
null
null
null
cs.LG cs.DC
http://creativecommons.org/licenses/by-nc-sa/4.0/
Many real-world problems involve massive amounts of data. Under these circumstances learning algorithms often become prohibitively expensive, making scalability a pressing issue to be addressed. A common approach is to perform sampling to reduce the size of the dataset and enable efficient learning. Alternatively, one customizes learning algorithms to achieve scalability. In either case, the key challenge is to obtain algorithmic efficiency without compromising the quality of the results. In this paper we discuss a meta-learning algorithm (PSBML) which combines features of parallel algorithms with concepts from ensemble and boosting methodologies to achieve the desired scalability property. We present both theoretical and empirical analyses which show that PSBML preserves a critical property of boosting, specifically, convergence to a distribution centered around the margin. We then present additional empirical analyses showing that this meta-level algorithm provides a general and effective framework that can be used in combination with a variety of learning classifiers. We perform extensive experiments to investigate the tradeoff achieved between scalability and accuracy, and robustness to noise, on both synthetic and real-world data. These empirical results corroborate our theoretical analysis, and demonstrate the potential of PSBML in achieving scalability without sacrificing accuracy.
[ { "version": "v1", "created": "Thu, 6 Aug 2015 21:54:34 GMT" } ]
2015-08-10T00:00:00
[ [ "Kamath", "Uday", "" ], [ "Domeniconi", "Carlotta", "" ], [ "De Jong", "Kenneth", "" ] ]
TITLE: Theoretical and Empirical Analysis of a Parallel Boosting Algorithm ABSTRACT: Many real-world problems involve massive amounts of data. Under these circumstances learning algorithms often become prohibitively expensive, making scalability a pressing issue to be addressed. A common approach is to perform sampling to reduce the size of the dataset and enable efficient learning. Alternatively, one customizes learning algorithms to achieve scalability. In either case, the key challenge is to obtain algorithmic efficiency without compromising the quality of the results. In this paper we discuss a meta-learning algorithm (PSBML) which combines features of parallel algorithms with concepts from ensemble and boosting methodologies to achieve the desired scalability property. We present both theoretical and empirical analyses which show that PSBML preserves a critical property of boosting, specifically, convergence to a distribution centered around the margin. We then present additional empirical analyses showing that this meta-level algorithm provides a general and effective framework that can be used in combination with a variety of learning classifiers. We perform extensive experiments to investigate the tradeoff achieved between scalability and accuracy, and robustness to noise, on both synthetic and real-world data. These empirical results corroborate our theoretical analysis, and demonstrate the potential of PSBML in achieving scalability without sacrificing accuracy.
no_new_dataset
0.945951
1508.01571
Humberto Corona
Humberto Corona, Michael P. O'Mahony
A Mood-based Genre Classification of Television Content
in ACM Workshop on Recommendation Systems for Television and Online Video 2014 Foster City, California USA
null
null
null
cs.IR cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The classification of television content helps users organise and navigate through the large list of channels and programs now available. In this paper, we address the problem of television content classification by exploiting text information extracted from program transcriptions. We present an analysis which adapts a model for sentiment that has been widely and successfully applied in other fields such as music or blog posts. We use a real-world dataset obtained from the Boxfish API to compare the performance of classifiers trained on a number of different feature sets. Our experiments show that, over a large collection of television content, program genres can be represented in a three-dimensional space of valence, arousal and dominance, and that promising classification results can be achieved using features based on this representation. This finding supports the use of the proposed representation of television content as a feature space for similarity computation and recommendation generation.
[ { "version": "v1", "created": "Thu, 6 Aug 2015 23:53:30 GMT" } ]
2015-08-10T00:00:00
[ [ "Corona", "Humberto", "" ], [ "O'Mahony", "Michael P.", "" ] ]
TITLE: A Mood-based Genre Classification of Television Content ABSTRACT: The classification of television content helps users organise and navigate through the large list of channels and programs now available. In this paper, we address the problem of television content classification by exploiting text information extracted from program transcriptions. We present an analysis which adapts a model for sentiment that has been widely and successfully applied in other fields such as music or blog posts. We use a real-world dataset obtained from the Boxfish API to compare the performance of classifiers trained on a number of different feature sets. Our experiments show that, over a large collection of television content, program genres can be represented in a three-dimensional space of valence, arousal and dominance, and that promising classification results can be achieved using features based on this representation. This finding supports the use of the proposed representation of television content as a feature space for similarity computation and recommendation generation.
no_new_dataset
0.946892
1508.01667
Limin Wang
Limin Wang, Sheng Guo, Weilin Huang, Yu Qiao
Places205-VGGNet Models for Scene Recognition
2 pages
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
VGGNets have turned out to be effective for object recognition in still images. However, it is unable to yield good performance by directly adapting the VGGNet models trained on the ImageNet dataset for scene recognition. This report describes our implementation of training the VGGNets on the large-scale Places205 dataset. Specifically, we train three VGGNet models, namely VGGNet-11, VGGNet-13, and VGGNet-16, by using a Multi-GPU extension of Caffe toolbox with high computational efficiency. We verify the performance of trained Places205-VGGNet models on three datasets: MIT67, SUN397, and Places205. Our trained models achieve the state-of-the-art performance on these datasets and are made public available.
[ { "version": "v1", "created": "Fri, 7 Aug 2015 12:11:06 GMT" } ]
2015-08-10T00:00:00
[ [ "Wang", "Limin", "" ], [ "Guo", "Sheng", "" ], [ "Huang", "Weilin", "" ], [ "Qiao", "Yu", "" ] ]
TITLE: Places205-VGGNet Models for Scene Recognition ABSTRACT: VGGNets have turned out to be effective for object recognition in still images. However, it is unable to yield good performance by directly adapting the VGGNet models trained on the ImageNet dataset for scene recognition. This report describes our implementation of training the VGGNets on the large-scale Places205 dataset. Specifically, we train three VGGNet models, namely VGGNet-11, VGGNet-13, and VGGNet-16, by using a Multi-GPU extension of Caffe toolbox with high computational efficiency. We verify the performance of trained Places205-VGGNet models on three datasets: MIT67, SUN397, and Places205. Our trained models achieve the state-of-the-art performance on these datasets and are made public available.
no_new_dataset
0.951051
1508.01696
Kasra Madadipouya
Kasra Madadipouya
A Location-Based Movie Recommender System Using Collaborative Filtering
7 pages in International Journal in Foundations of Computer Science & Technology (IJFCST), Vol.5, No.4, July 2015
null
10.5121/ijfcst.2015.5402
null
cs.IR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Available recommender systems mostly provide recommendations based on the users preferences by utilizing traditional methods such as collaborative filtering which only relies on the similarities between users and items. However, collaborative filtering might lead to provide poor recommendation because it does not rely on other useful available data such as users locations and hence the accuracy of the recommendations could be very low and inefficient. This could be very obvious in the systems that locations would affect users preferences highly such as movie recommender systems. In this paper a new location-based movie recommender system based on the collaborative filtering is introduced for enhancing the accuracy and the quality of recommendations. In this approach, users locations have been utilized and take in consideration in the entire processing of the recommendations and peer selections. The potential of the proposed approach in providing novel and better quality recommendations have been discussed through experiments in real datasets.
[ { "version": "v1", "created": "Fri, 7 Aug 2015 14:03:41 GMT" } ]
2015-08-10T00:00:00
[ [ "Madadipouya", "Kasra", "" ] ]
TITLE: A Location-Based Movie Recommender System Using Collaborative Filtering ABSTRACT: Available recommender systems mostly provide recommendations based on the users preferences by utilizing traditional methods such as collaborative filtering which only relies on the similarities between users and items. However, collaborative filtering might lead to provide poor recommendation because it does not rely on other useful available data such as users locations and hence the accuracy of the recommendations could be very low and inefficient. This could be very obvious in the systems that locations would affect users preferences highly such as movie recommender systems. In this paper a new location-based movie recommender system based on the collaborative filtering is introduced for enhancing the accuracy and the quality of recommendations. In this approach, users locations have been utilized and take in consideration in the entire processing of the recommendations and peer selections. The potential of the proposed approach in providing novel and better quality recommendations have been discussed through experiments in real datasets.
no_new_dataset
0.950824
1508.01753
Martin Marinov Mr
Martin Marinov, Nicholas Nash and David Gregg
Practical Algorithms for Finding Extremal Sets
null
null
null
null
cs.DS
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The minimal sets within a collection of sets are defined as the ones which do not have a proper subset within the collection, and the maximal sets are the ones which do not have a proper superset within the collection. Identifying extremal sets is a fundamental problem with a wide-range of applications in SAT solvers, data-mining and social network analysis. In this paper, we present two novel improvements of the high-quality extremal set identification algorithm, \textit{AMS-Lex}, described by Bayardo and Panda. The first technique uses memoization to improve the execution time of the single-threaded variant of the AMS-Lex, whilst our second improvement uses parallel programming methods. In a subset of the presented experiments our memoized algorithm executes more than $400$ times faster than the highly efficient publicly available implementation of AMS-Lex. Moreover, we show that our modified algorithm's speedup is not bounded above by a constant and that it increases as the length of the common prefixes in successive input \textit{itemsets} increases. We provide experimental results using both real-world and synthetic data sets, and show our multi-threaded variant algorithm out-performing AMS-Lex by $3$ to $6$ times. We find that on synthetic input datasets when executed using $16$ CPU cores of a $32$-core machine, our multi-threaded program executes about as fast as the state of the art parallel GPU-based program using an NVIDIA GTX 580 graphics processing unit.
[ { "version": "v1", "created": "Fri, 7 Aug 2015 16:33:54 GMT" } ]
2015-08-10T00:00:00
[ [ "Marinov", "Martin", "" ], [ "Nash", "Nicholas", "" ], [ "Gregg", "David", "" ] ]
TITLE: Practical Algorithms for Finding Extremal Sets ABSTRACT: The minimal sets within a collection of sets are defined as the ones which do not have a proper subset within the collection, and the maximal sets are the ones which do not have a proper superset within the collection. Identifying extremal sets is a fundamental problem with a wide-range of applications in SAT solvers, data-mining and social network analysis. In this paper, we present two novel improvements of the high-quality extremal set identification algorithm, \textit{AMS-Lex}, described by Bayardo and Panda. The first technique uses memoization to improve the execution time of the single-threaded variant of the AMS-Lex, whilst our second improvement uses parallel programming methods. In a subset of the presented experiments our memoized algorithm executes more than $400$ times faster than the highly efficient publicly available implementation of AMS-Lex. Moreover, we show that our modified algorithm's speedup is not bounded above by a constant and that it increases as the length of the common prefixes in successive input \textit{itemsets} increases. We provide experimental results using both real-world and synthetic data sets, and show our multi-threaded variant algorithm out-performing AMS-Lex by $3$ to $6$ times. We find that on synthetic input datasets when executed using $16$ CPU cores of a $32$-core machine, our multi-threaded program executes about as fast as the state of the art parallel GPU-based program using an NVIDIA GTX 580 graphics processing unit.
no_new_dataset
0.946745
1508.01755
Tsung-Hsien Wen
Tsung-Hsien Wen, Milica Gasic, Dongho Kim, Nikola Mrksic, Pei-Hao Su, David Vandyke, Steve Young
Stochastic Language Generation in Dialogue using Recurrent Neural Networks with Convolutional Sentence Reranking
To be appear in SigDial 2015
null
null
null
cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The natural language generation (NLG) component of a spoken dialogue system (SDS) usually needs a substantial amount of handcrafting or a well-labeled dataset to be trained on. These limitations add significantly to development costs and make cross-domain, multi-lingual dialogue systems intractable. Moreover, human languages are context-aware. The most natural response should be directly learned from data rather than depending on predefined syntaxes or rules. This paper presents a statistical language generator based on a joint recurrent and convolutional neural network structure which can be trained on dialogue act-utterance pairs without any semantic alignments or predefined grammar trees. Objective metrics suggest that this new model outperforms previous methods under the same experimental conditions. Results of an evaluation by human judges indicate that it produces not only high quality but linguistically varied utterances which are preferred compared to n-gram and rule-based systems.
[ { "version": "v1", "created": "Fri, 7 Aug 2015 16:34:11 GMT" } ]
2015-08-10T00:00:00
[ [ "Wen", "Tsung-Hsien", "" ], [ "Gasic", "Milica", "" ], [ "Kim", "Dongho", "" ], [ "Mrksic", "Nikola", "" ], [ "Su", "Pei-Hao", "" ], [ "Vandyke", "David", "" ], [ "Young", "Steve", "" ] ]
TITLE: Stochastic Language Generation in Dialogue using Recurrent Neural Networks with Convolutional Sentence Reranking ABSTRACT: The natural language generation (NLG) component of a spoken dialogue system (SDS) usually needs a substantial amount of handcrafting or a well-labeled dataset to be trained on. These limitations add significantly to development costs and make cross-domain, multi-lingual dialogue systems intractable. Moreover, human languages are context-aware. The most natural response should be directly learned from data rather than depending on predefined syntaxes or rules. This paper presents a statistical language generator based on a joint recurrent and convolutional neural network structure which can be trained on dialogue act-utterance pairs without any semantic alignments or predefined grammar trees. Objective metrics suggest that this new model outperforms previous methods under the same experimental conditions. Results of an evaluation by human judges indicate that it produces not only high quality but linguistically varied utterances which are preferred compared to n-gram and rule-based systems.
no_new_dataset
0.952486
1508.01420
Luis Marujo
Lu\'is Marujo, Jos\'e Port\^elo, Wang Ling, David Martins de Matos, Jo\~ao P. Neto, Anatole Gershman, Jaime Carbonell, Isabel Trancoso, Bhiksha Raj
Privacy-Preserving Multi-Document Summarization
4 pages, In Proceedings of 2nd ACM SIGIR Workshop on Privacy-Preserving Information Retrieval, August 2015. arXiv admin note: text overlap with arXiv:1407.5416
null
null
null
cs.IR cs.CL cs.CR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
State-of-the-art extractive multi-document summarization systems are usually designed without any concern about privacy issues, meaning that all documents are open to third parties. In this paper we propose a privacy-preserving approach to multi-document summarization. Our approach enables other parties to obtain summaries without learning anything else about the original documents' content. We use a hashing scheme known as Secure Binary Embeddings to convert documents representation containing key phrases and bag-of-words into bit strings, allowing the computation of approximate distances, instead of exact ones. Our experiments indicate that our system yields similar results to its non-private counterpart on standard multi-document evaluation datasets.
[ { "version": "v1", "created": "Thu, 6 Aug 2015 14:30:47 GMT" } ]
2015-08-07T00:00:00
[ [ "Marujo", "Luís", "" ], [ "Portêlo", "José", "" ], [ "Ling", "Wang", "" ], [ "de Matos", "David Martins", "" ], [ "Neto", "João P.", "" ], [ "Gershman", "Anatole", "" ], [ "Carbonell", "Jaime", "" ], [ "Trancoso", "Isabel", "" ], [ "Raj", "Bhiksha", "" ] ]
TITLE: Privacy-Preserving Multi-Document Summarization ABSTRACT: State-of-the-art extractive multi-document summarization systems are usually designed without any concern about privacy issues, meaning that all documents are open to third parties. In this paper we propose a privacy-preserving approach to multi-document summarization. Our approach enables other parties to obtain summaries without learning anything else about the original documents' content. We use a hashing scheme known as Secure Binary Embeddings to convert documents representation containing key phrases and bag-of-words into bit strings, allowing the computation of approximate distances, instead of exact ones. Our experiments indicate that our system yields similar results to its non-private counterpart on standard multi-document evaluation datasets.
no_new_dataset
0.946745
1508.01447
Iyad AlAgha
Iyad AlAgha
Using Linguistic Analysis to Translate Arabic Natural Language Queries to SPARQL
Journal Paper
null
null
null
cs.CL cs.AI cs.DB
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The logic-based machine-understandable framework of the Semantic Web often challenges naive users when they try to query ontology-based knowledge bases. Existing research efforts have approached this problem by introducing Natural Language (NL) interfaces to ontologies. These NL interfaces have the ability to construct SPARQL queries based on NL user queries. However, most efforts were restricted to queries expressed in English, and they often benefited from the advancement of English NLP tools. However, little research has been done to support querying the Arabic content on the Semantic Web by using NL queries. This paper presents a domain-independent approach to translate Arabic NL queries to SPARQL by leveraging linguistic analysis. Based on a special consideration on Noun Phrases (NPs), our approach uses a language parser to extract NPs and the relations from Arabic parse trees and match them to the underlying ontology. It then utilizes knowledge in the ontology to group NPs into triple-based representations. A SPARQL query is finally generated by extracting targets and modifiers, and interpreting them into SPARQL. The interpretation of advanced semantic features including negation, conjunctive and disjunctive modifiers is also supported. The approach was evaluated by using two datasets consisting of OWL test data and queries, and the obtained results have confirmed its feasibility to translate Arabic NL queries to SPARQL.
[ { "version": "v1", "created": "Thu, 6 Aug 2015 16:10:21 GMT" } ]
2015-08-07T00:00:00
[ [ "AlAgha", "Iyad", "" ] ]
TITLE: Using Linguistic Analysis to Translate Arabic Natural Language Queries to SPARQL ABSTRACT: The logic-based machine-understandable framework of the Semantic Web often challenges naive users when they try to query ontology-based knowledge bases. Existing research efforts have approached this problem by introducing Natural Language (NL) interfaces to ontologies. These NL interfaces have the ability to construct SPARQL queries based on NL user queries. However, most efforts were restricted to queries expressed in English, and they often benefited from the advancement of English NLP tools. However, little research has been done to support querying the Arabic content on the Semantic Web by using NL queries. This paper presents a domain-independent approach to translate Arabic NL queries to SPARQL by leveraging linguistic analysis. Based on a special consideration on Noun Phrases (NPs), our approach uses a language parser to extract NPs and the relations from Arabic parse trees and match them to the underlying ontology. It then utilizes knowledge in the ontology to group NPs into triple-based representations. A SPARQL query is finally generated by extracting targets and modifiers, and interpreting them into SPARQL. The interpretation of advanced semantic features including negation, conjunctive and disjunctive modifiers is also supported. The approach was evaluated by using two datasets consisting of OWL test data and queries, and the obtained results have confirmed its feasibility to translate Arabic NL queries to SPARQL.
no_new_dataset
0.944228
1505.03823
Miao Fan
Miao Fan, Qiang Zhou and Thomas Fang Zheng
Distant Supervision for Entity Linking
null
null
null
null
cs.CL cs.IR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Entity linking is an indispensable operation of populating knowledge repositories for information extraction. It studies on aligning a textual entity mention to its corresponding disambiguated entry in a knowledge repository. In this paper, we propose a new paradigm named distantly supervised entity linking (DSEL), in the sense that the disambiguated entities that belong to a huge knowledge repository (Freebase) are automatically aligned to the corresponding descriptive webpages (Wiki pages). In this way, a large scale of weakly labeled data can be generated without manual annotation and fed to a classifier for linking more newly discovered entities. Compared with traditional paradigms based on solo knowledge base, DSEL benefits more via jointly leveraging the respective advantages of Freebase and Wikipedia. Specifically, the proposed paradigm facilitates bridging the disambiguated labels (Freebase) of entities and their textual descriptions (Wikipedia) for Web-scale entities. Experiments conducted on a dataset of 140,000 items and 60,000 features achieve a baseline F1-measure of 0.517. Furthermore, we analyze the feature performance and improve the F1-measure to 0.545.
[ { "version": "v1", "created": "Thu, 14 May 2015 18:15:49 GMT" }, { "version": "v2", "created": "Tue, 19 May 2015 14:45:19 GMT" }, { "version": "v3", "created": "Wed, 5 Aug 2015 01:25:26 GMT" } ]
2015-08-06T00:00:00
[ [ "Fan", "Miao", "" ], [ "Zhou", "Qiang", "" ], [ "Zheng", "Thomas Fang", "" ] ]
TITLE: Distant Supervision for Entity Linking ABSTRACT: Entity linking is an indispensable operation of populating knowledge repositories for information extraction. It studies on aligning a textual entity mention to its corresponding disambiguated entry in a knowledge repository. In this paper, we propose a new paradigm named distantly supervised entity linking (DSEL), in the sense that the disambiguated entities that belong to a huge knowledge repository (Freebase) are automatically aligned to the corresponding descriptive webpages (Wiki pages). In this way, a large scale of weakly labeled data can be generated without manual annotation and fed to a classifier for linking more newly discovered entities. Compared with traditional paradigms based on solo knowledge base, DSEL benefits more via jointly leveraging the respective advantages of Freebase and Wikipedia. Specifically, the proposed paradigm facilitates bridging the disambiguated labels (Freebase) of entities and their textual descriptions (Wikipedia) for Web-scale entities. Experiments conducted on a dataset of 140,000 items and 60,000 features achieve a baseline F1-measure of 0.517. Furthermore, we analyze the feature performance and improve the F1-measure to 0.545.
no_new_dataset
0.937038
1507.02206
Won-Yong Shin
Won-Yong Shin, Bikash C. Singh, Jaehee Cho, and Andr\'e M. Everett
A New Understanding of Friendships in Space: Complex Networks Meet Twitter
17 pages, 5 figures, 6 tables, To appear in Journal of Information Science (Special Issue on Recent Advances on Big Social Data)
null
null
null
cs.SI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Studies on friendships in online social networks involving geographic distance have so far relied on the city location provided in users' profiles. Consequently, most of the research on friendships have provided accuracy at the city level, at best, to designate a user's location. This study analyzes a Twitter dataset because it provides the exact geographic distance between corresponding users. We start by introducing a strong definition of "friend" on Twitter (i.e., a definition of bidirectional friendship), requiring bidirectional communication. Next, we utilize geo-tagged mentions delivered by users to determine their locations, where "@username" is contained anywhere in the body of tweets. To provide analysis results, we first introduce a friend counting algorithm. From the fact that Twitter users are likely to post consecutive tweets in the static mode, we also introduce a two-stage distance estimation algorithm. As the first of our main contributions, we verify that the number of friends of a particular Twitter user follows a well-known power-law distribution (i.e., a Zipf's distribution or a Pareto distribution). Our study also provides the following newly-discovered friendship degree related to the issue of space: The number of friends according to distance follows a double power-law (i.e., a double Pareto law) distribution, indicating that the probability of befriending a particular Twitter user is significantly reduced beyond a certain geographic distance between users, termed the separation point. Our analysis provides concrete evidence that Twitter can be a useful platform for assigning a more accurate scalar value to the degree of friendship between two users.
[ { "version": "v1", "created": "Wed, 8 Jul 2015 16:06:47 GMT" }, { "version": "v2", "created": "Sat, 18 Jul 2015 12:12:25 GMT" }, { "version": "v3", "created": "Tue, 21 Jul 2015 07:18:13 GMT" }, { "version": "v4", "created": "Wed, 5 Aug 2015 08:51:02 GMT" } ]
2015-08-06T00:00:00
[ [ "Shin", "Won-Yong", "" ], [ "Singh", "Bikash C.", "" ], [ "Cho", "Jaehee", "" ], [ "Everett", "André M.", "" ] ]
TITLE: A New Understanding of Friendships in Space: Complex Networks Meet Twitter ABSTRACT: Studies on friendships in online social networks involving geographic distance have so far relied on the city location provided in users' profiles. Consequently, most of the research on friendships have provided accuracy at the city level, at best, to designate a user's location. This study analyzes a Twitter dataset because it provides the exact geographic distance between corresponding users. We start by introducing a strong definition of "friend" on Twitter (i.e., a definition of bidirectional friendship), requiring bidirectional communication. Next, we utilize geo-tagged mentions delivered by users to determine their locations, where "@username" is contained anywhere in the body of tweets. To provide analysis results, we first introduce a friend counting algorithm. From the fact that Twitter users are likely to post consecutive tweets in the static mode, we also introduce a two-stage distance estimation algorithm. As the first of our main contributions, we verify that the number of friends of a particular Twitter user follows a well-known power-law distribution (i.e., a Zipf's distribution or a Pareto distribution). Our study also provides the following newly-discovered friendship degree related to the issue of space: The number of friends according to distance follows a double power-law (i.e., a double Pareto law) distribution, indicating that the probability of befriending a particular Twitter user is significantly reduced beyond a certain geographic distance between users, termed the separation point. Our analysis provides concrete evidence that Twitter can be a useful platform for assigning a more accurate scalar value to the degree of friendship between two users.
no_new_dataset
0.9434
1508.00966
Yankui Sun
Yankui Sun, Tian Zhang, Yue Zhao, Yufan He
3D Automatic Segmentation Method for Retinal Optical Coherence Tomography Volume Data Using Boundary Surface Enhancement
27 pages, 19 figures
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
With the introduction of spectral-domain optical coherence tomography (SDOCT), much larger image datasets are routinely acquired compared to what was possible using the previous generation of time-domain OCT. Thus, there is a critical need for the development of 3D segmentation methods for processing these data. We present here a novel 3D automatic segmentation method for retinal OCT volume data. Briefly, to segment a boundary surface, two OCT volume datasets are obtained by using a 3D smoothing filter and a 3D differential filter. Their linear combination is then calculated to generate new volume data with an enhanced boundary surface, where pixel intensity, boundary position information, and intensity changes on both sides of the boundary surface are used simultaneously. Next, preliminary discrete boundary points are detected from the A-Scans of the volume data. Finally, surface smoothness constraints and a dynamic threshold are applied to obtain a smoothed boundary surface by correcting a small number of error points. Our method can extract retinal layer boundary surfaces sequentially with a decreasing search region of volume data. We performed automatic segmentation on eight human OCT volume datasets acquired from a commercial Spectralis OCT system, where each volume of data consisted of 97 OCT images with a resolution of 496 512; experimental results show that this method can accurately segment seven layer boundary surfaces in normal as well as some abnormal eyes.
[ { "version": "v1", "created": "Wed, 5 Aug 2015 03:42:54 GMT" } ]
2015-08-06T00:00:00
[ [ "Sun", "Yankui", "" ], [ "Zhang", "Tian", "" ], [ "Zhao", "Yue", "" ], [ "He", "Yufan", "" ] ]
TITLE: 3D Automatic Segmentation Method for Retinal Optical Coherence Tomography Volume Data Using Boundary Surface Enhancement ABSTRACT: With the introduction of spectral-domain optical coherence tomography (SDOCT), much larger image datasets are routinely acquired compared to what was possible using the previous generation of time-domain OCT. Thus, there is a critical need for the development of 3D segmentation methods for processing these data. We present here a novel 3D automatic segmentation method for retinal OCT volume data. Briefly, to segment a boundary surface, two OCT volume datasets are obtained by using a 3D smoothing filter and a 3D differential filter. Their linear combination is then calculated to generate new volume data with an enhanced boundary surface, where pixel intensity, boundary position information, and intensity changes on both sides of the boundary surface are used simultaneously. Next, preliminary discrete boundary points are detected from the A-Scans of the volume data. Finally, surface smoothness constraints and a dynamic threshold are applied to obtain a smoothed boundary surface by correcting a small number of error points. Our method can extract retinal layer boundary surfaces sequentially with a decreasing search region of volume data. We performed automatic segmentation on eight human OCT volume datasets acquired from a commercial Spectralis OCT system, where each volume of data consisted of 97 OCT images with a resolution of 496 512; experimental results show that this method can accurately segment seven layer boundary surfaces in normal as well as some abnormal eyes.
no_new_dataset
0.956513
1508.00973
Peixian Chen
Peixian Chen, Nevin L. Zhang, Leonard K.M. Poon, Zhourong Chen
Progressive EM for Latent Tree Models and Hierarchical Topic Detection
null
null
null
null
cs.LG cs.CL cs.IR stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Hierarchical latent tree analysis (HLTA) is recently proposed as a new method for topic detection. It differs fundamentally from the LDA-based methods in terms of topic definition, topic-document relationship, and learning method. It has been shown to discover significantly more coherent topics and better topic hierarchies. However, HLTA relies on the Expectation-Maximization (EM) algorithm for parameter estimation and hence is not efficient enough to deal with large datasets. In this paper, we propose a method to drastically speed up HLTA using a technique inspired by recent advances in the moments method. Empirical experiments show that our method greatly improves the efficiency of HLTA. It is as efficient as the state-of-the-art LDA-based method for hierarchical topic detection and finds substantially better topics and topic hierarchies.
[ { "version": "v1", "created": "Wed, 5 Aug 2015 05:00:32 GMT" } ]
2015-08-06T00:00:00
[ [ "Chen", "Peixian", "" ], [ "Zhang", "Nevin L.", "" ], [ "Poon", "Leonard K. M.", "" ], [ "Chen", "Zhourong", "" ] ]
TITLE: Progressive EM for Latent Tree Models and Hierarchical Topic Detection ABSTRACT: Hierarchical latent tree analysis (HLTA) is recently proposed as a new method for topic detection. It differs fundamentally from the LDA-based methods in terms of topic definition, topic-document relationship, and learning method. It has been shown to discover significantly more coherent topics and better topic hierarchies. However, HLTA relies on the Expectation-Maximization (EM) algorithm for parameter estimation and hence is not efficient enough to deal with large datasets. In this paper, we propose a method to drastically speed up HLTA using a technique inspired by recent advances in the moments method. Empirical experiments show that our method greatly improves the efficiency of HLTA. It is as efficient as the state-of-the-art LDA-based method for hierarchical topic detection and finds substantially better topics and topic hierarchies.
no_new_dataset
0.948917
1508.01192
Paulo Shakarian
Andrew Stanton, Amanda Thart, Ashish Jain, Priyank Vyas, Arpan Chatterjee, Paulo Shakarian
Mining for Causal Relationships: A Data-Driven Study of the Islamic State
null
Final version presented at KDD 2015
null
null
cs.CY cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Islamic State of Iraq and al-Sham (ISIS) is a dominant insurgent group operating in Iraq and Syria that rose to prominence when it took over Mosul in June, 2014. In this paper, we present a data-driven approach to analyzing this group using a dataset consisting of 2200 incidents of military activity surrounding ISIS and the forces that oppose it (including Iraqi, Syrian, and the American-led coalition). We combine ideas from logic programming and causal reasoning to mine for association rules for which we present evidence of causality. We present relationships that link ISIS vehicle-bourne improvised explosive device (VBIED) activity in Syria with military operations in Iraq, coalition air strikes, and ISIS IED activity, as well as rules that may serve as indicators of spikes in indirect fire, suicide attacks, and arrests.
[ { "version": "v1", "created": "Wed, 5 Aug 2015 19:50:54 GMT" } ]
2015-08-06T00:00:00
[ [ "Stanton", "Andrew", "" ], [ "Thart", "Amanda", "" ], [ "Jain", "Ashish", "" ], [ "Vyas", "Priyank", "" ], [ "Chatterjee", "Arpan", "" ], [ "Shakarian", "Paulo", "" ] ]
TITLE: Mining for Causal Relationships: A Data-Driven Study of the Islamic State ABSTRACT: The Islamic State of Iraq and al-Sham (ISIS) is a dominant insurgent group operating in Iraq and Syria that rose to prominence when it took over Mosul in June, 2014. In this paper, we present a data-driven approach to analyzing this group using a dataset consisting of 2200 incidents of military activity surrounding ISIS and the forces that oppose it (including Iraqi, Syrian, and the American-led coalition). We combine ideas from logic programming and causal reasoning to mine for association rules for which we present evidence of causality. We present relationships that link ISIS vehicle-bourne improvised explosive device (VBIED) activity in Syria with military operations in Iraq, coalition air strikes, and ISIS IED activity, as well as rules that may serve as indicators of spikes in indirect fire, suicide attacks, and arrests.
new_dataset
0.967256
1408.5418
Jianping Shi
Jianping Shi, Qiong Yan, Li Xu, Jiaya Jia
Hierarchical Saliency Detection on Extended CSSD
14 pages, 15 figures
null
null
CUHK-CSE-201408
cs.CV
http://creativecommons.org/licenses/by/4.0/
Complex structures commonly exist in natural images. When an image contains small-scale high-contrast patterns either in the background or foreground, saliency detection could be adversely affected, resulting erroneous and non-uniform saliency assignment. The issue forms a fundamental challenge for prior methods. We tackle it from a scale point of view and propose a multi-layer approach to analyze saliency cues. Different from varying patch sizes or downsizing images, we measure region-based scales. The final saliency values are inferred optimally combining all the saliency cues in different scales using hierarchical inference. Through our inference model, single-scale information is selected to obtain a saliency map. Our method improves detection quality on many images that cannot be handled well traditionally. We also construct an extended Complex Scene Saliency Dataset (ECSSD) to include complex but general natural images.
[ { "version": "v1", "created": "Mon, 11 Aug 2014 15:18:47 GMT" }, { "version": "v2", "created": "Tue, 4 Aug 2015 07:49:43 GMT" } ]
2015-08-05T00:00:00
[ [ "Shi", "Jianping", "" ], [ "Yan", "Qiong", "" ], [ "Xu", "Li", "" ], [ "Jia", "Jiaya", "" ] ]
TITLE: Hierarchical Saliency Detection on Extended CSSD ABSTRACT: Complex structures commonly exist in natural images. When an image contains small-scale high-contrast patterns either in the background or foreground, saliency detection could be adversely affected, resulting erroneous and non-uniform saliency assignment. The issue forms a fundamental challenge for prior methods. We tackle it from a scale point of view and propose a multi-layer approach to analyze saliency cues. Different from varying patch sizes or downsizing images, we measure region-based scales. The final saliency values are inferred optimally combining all the saliency cues in different scales using hierarchical inference. Through our inference model, single-scale information is selected to obtain a saliency map. Our method improves detection quality on many images that cannot be handled well traditionally. We also construct an extended Complex Scene Saliency Dataset (ECSSD) to include complex but general natural images.
new_dataset
0.943919
1502.06435
Philip Schniter
Jeremy Vila, Philip Schniter, and Joseph Meola
Hyperspectral Unmixing via Turbo Bilinear Approximate Message Passing
null
null
null
null
cs.IT math.IT
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The goal of hyperspectral unmixing is to decompose an electromagnetic spectral dataset measured over M spectral bands and T pixels into N constituent material spectra (or "end-members") with corresponding spatial abundances. In this paper, we propose a novel approach to hyperspectral unmixing based on loopy belief propagation (BP) that enables the exploitation of spectral coherence in the endmembers and spatial coherence in the abundances. In particular, we partition the factor graph into spectral coherence, spatial coherence, and bilinear subgraphs, and pass messages between them using a "turbo" approach. To perform message passing within the bilinear subgraph, we employ the bilinear generalized approximate message passing algorithm (BiG-AMP), a recently proposed belief-propagation-based approach to matrix factorization. Furthermore, we propose an expectation-maximization (EM) strategy to tune the prior parameters and a model-order selection strategy to select the number of materials N. Numerical experiments conducted with both synthetic and real-world data show favorable unmixing performance relative to existing methods.
[ { "version": "v1", "created": "Mon, 23 Feb 2015 14:13:01 GMT" }, { "version": "v2", "created": "Tue, 4 Aug 2015 13:39:06 GMT" } ]
2015-08-05T00:00:00
[ [ "Vila", "Jeremy", "" ], [ "Schniter", "Philip", "" ], [ "Meola", "Joseph", "" ] ]
TITLE: Hyperspectral Unmixing via Turbo Bilinear Approximate Message Passing ABSTRACT: The goal of hyperspectral unmixing is to decompose an electromagnetic spectral dataset measured over M spectral bands and T pixels into N constituent material spectra (or "end-members") with corresponding spatial abundances. In this paper, we propose a novel approach to hyperspectral unmixing based on loopy belief propagation (BP) that enables the exploitation of spectral coherence in the endmembers and spatial coherence in the abundances. In particular, we partition the factor graph into spectral coherence, spatial coherence, and bilinear subgraphs, and pass messages between them using a "turbo" approach. To perform message passing within the bilinear subgraph, we employ the bilinear generalized approximate message passing algorithm (BiG-AMP), a recently proposed belief-propagation-based approach to matrix factorization. Furthermore, we propose an expectation-maximization (EM) strategy to tune the prior parameters and a model-order selection strategy to select the number of materials N. Numerical experiments conducted with both synthetic and real-world data show favorable unmixing performance relative to existing methods.
no_new_dataset
0.950549
1508.00430
Mengyang Yu
Mengyang Yu, Li Liu, Ling Shao
Kernelized Multiview Projection
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Conventional vision algorithms adopt a single type of feature or a simple concatenation of multiple features, which is always represented in a high-dimensional space. In this paper, we propose a novel unsupervised spectral embedding algorithm called Kernelized Multiview Projection (KMP) to better fuse and embed different feature representations. Computing the kernel matrices from different features/views, KMP can encode them with the corresponding weights to achieve a low-dimensional and semantically meaningful subspace where the distribution of each view is sufficiently smooth and discriminative. More crucially, KMP is linear for the reproducing kernel Hilbert space (RKHS) and solves the out-of-sample problem, which allows it to be competent for various practical applications. Extensive experiments on three popular image datasets demonstrate the effectiveness of our multiview embedding algorithm.
[ { "version": "v1", "created": "Mon, 3 Aug 2015 14:33:03 GMT" }, { "version": "v2", "created": "Tue, 4 Aug 2015 09:42:14 GMT" } ]
2015-08-05T00:00:00
[ [ "Yu", "Mengyang", "" ], [ "Liu", "Li", "" ], [ "Shao", "Ling", "" ] ]
TITLE: Kernelized Multiview Projection ABSTRACT: Conventional vision algorithms adopt a single type of feature or a simple concatenation of multiple features, which is always represented in a high-dimensional space. In this paper, we propose a novel unsupervised spectral embedding algorithm called Kernelized Multiview Projection (KMP) to better fuse and embed different feature representations. Computing the kernel matrices from different features/views, KMP can encode them with the corresponding weights to achieve a low-dimensional and semantically meaningful subspace where the distribution of each view is sufficiently smooth and discriminative. More crucially, KMP is linear for the reproducing kernel Hilbert space (RKHS) and solves the out-of-sample problem, which allows it to be competent for various practical applications. Extensive experiments on three popular image datasets demonstrate the effectiveness of our multiview embedding algorithm.
no_new_dataset
0.947332
1508.00749
Indre Zliobaite
Tomas Krilavicius, Indre Zliobaite, Henrikas Simonavicius and Laimonas Jarusevicius
Predicting respiratory motion for real-time tumour tracking in radiotherapy
null
null
null
null
cs.AI cs.CE physics.med-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Purpose. Radiation therapy is a local treatment aimed at cells in and around a tumor. The goal of this study is to develop an algorithmic solution for predicting the position of a target in 3D in real time, aiming for the short fixed calibration time for each patient at the beginning of the procedure. Accurate predictions of lung tumor motion are expected to improve the precision of radiation treatment by controlling the position of a couch or a beam in order to compensate for respiratory motion during radiation treatment. Methods. For developing the algorithmic solution, data mining techniques are used. A model form from the family of exponential smoothing is assumed, and the model parameters are fitted by minimizing the absolute disposition error, and the fluctuations of the prediction signal (jitter). The predictive performance is evaluated retrospectively on clinical datasets capturing different behavior (being quiet, talking, laughing), and validated in real-time on a prototype system with respiratory motion imitation. Results. An algorithmic solution for respiratory motion prediction (called ExSmi) is designed. ExSmi achieves good accuracy of prediction (error $4-9$ mm/s) with acceptable jitter values (5-7 mm/s), as tested on out-of-sample data. The datasets, the code for algorithms and the experiments are openly available for research purposes on a dedicated website. Conclusions. The developed algorithmic solution performs well to be prototyped and deployed in applications of radiotherapy.
[ { "version": "v1", "created": "Tue, 4 Aug 2015 12:26:00 GMT" } ]
2015-08-05T00:00:00
[ [ "Krilavicius", "Tomas", "" ], [ "Zliobaite", "Indre", "" ], [ "Simonavicius", "Henrikas", "" ], [ "Jarusevicius", "Laimonas", "" ] ]
TITLE: Predicting respiratory motion for real-time tumour tracking in radiotherapy ABSTRACT: Purpose. Radiation therapy is a local treatment aimed at cells in and around a tumor. The goal of this study is to develop an algorithmic solution for predicting the position of a target in 3D in real time, aiming for the short fixed calibration time for each patient at the beginning of the procedure. Accurate predictions of lung tumor motion are expected to improve the precision of radiation treatment by controlling the position of a couch or a beam in order to compensate for respiratory motion during radiation treatment. Methods. For developing the algorithmic solution, data mining techniques are used. A model form from the family of exponential smoothing is assumed, and the model parameters are fitted by minimizing the absolute disposition error, and the fluctuations of the prediction signal (jitter). The predictive performance is evaluated retrospectively on clinical datasets capturing different behavior (being quiet, talking, laughing), and validated in real-time on a prototype system with respiratory motion imitation. Results. An algorithmic solution for respiratory motion prediction (called ExSmi) is designed. ExSmi achieves good accuracy of prediction (error $4-9$ mm/s) with acceptable jitter values (5-7 mm/s), as tested on out-of-sample data. The datasets, the code for algorithms and the experiments are openly available for research purposes on a dedicated website. Conclusions. The developed algorithmic solution performs well to be prototyped and deployed in applications of radiotherapy.
no_new_dataset
0.949763
1508.00776
Eleonora Vig
Adrien Gaidon and Eleonora Vig
Online Domain Adaptation for Multi-Object Tracking
To appear at BMVC 2015
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Automatically detecting, labeling, and tracking objects in videos depends first and foremost on accurate category-level object detectors. These might, however, not always be available in practice, as acquiring high-quality large scale labeled training datasets is either too costly or impractical for all possible real-world application scenarios. A scalable solution consists in re-using object detectors pre-trained on generic datasets. This work is the first to investigate the problem of on-line domain adaptation of object detectors for causal multi-object tracking (MOT). We propose to alleviate the dataset bias by adapting detectors from category to instances, and back: (i) we jointly learn all target models by adapting them from the pre-trained one, and (ii) we also adapt the pre-trained model on-line. We introduce an on-line multi-task learning algorithm to efficiently share parameters and reduce drift, while gradually improving recall. Our approach is applicable to any linear object detector, and we evaluate both cheap "mini-Fisher Vectors" and expensive "off-the-shelf" ConvNet features. We quantitatively measure the benefit of our domain adaptation strategy on the KITTI tracking benchmark and on a new dataset (PASCAL-to-KITTI) we introduce to study the domain mismatch problem in MOT.
[ { "version": "v1", "created": "Tue, 4 Aug 2015 14:01:55 GMT" } ]
2015-08-05T00:00:00
[ [ "Gaidon", "Adrien", "" ], [ "Vig", "Eleonora", "" ] ]
TITLE: Online Domain Adaptation for Multi-Object Tracking ABSTRACT: Automatically detecting, labeling, and tracking objects in videos depends first and foremost on accurate category-level object detectors. These might, however, not always be available in practice, as acquiring high-quality large scale labeled training datasets is either too costly or impractical for all possible real-world application scenarios. A scalable solution consists in re-using object detectors pre-trained on generic datasets. This work is the first to investigate the problem of on-line domain adaptation of object detectors for causal multi-object tracking (MOT). We propose to alleviate the dataset bias by adapting detectors from category to instances, and back: (i) we jointly learn all target models by adapting them from the pre-trained one, and (ii) we also adapt the pre-trained model on-line. We introduce an on-line multi-task learning algorithm to efficiently share parameters and reduce drift, while gradually improving recall. Our approach is applicable to any linear object detector, and we evaluate both cheap "mini-Fisher Vectors" and expensive "off-the-shelf" ConvNet features. We quantitatively measure the benefit of our domain adaptation strategy on the KITTI tracking benchmark and on a new dataset (PASCAL-to-KITTI) we introduce to study the domain mismatch problem in MOT.
no_new_dataset
0.943348
1508.00088
Shashaank Sivakumar
D.S. Shashaank, V. Sruthi, M.L.S Vijayalakshimi and Jacob Shomona Garcia
Turnover Prediction Of Shares using Data Mining techniques : A Case Study
null
null
null
null
cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Predicting the turnover of a company in the ever fluctuating Stock market has always proved to be a precarious situation and most certainly a difficult task in hand. Data mining is a well-known sphere of Computer Science that aims on extracting meaningful information from large databases. However, despite the existence of many algorithms for the purpose of predicting the future trends, their efficiency is questionable as their predictions suffer from a high error rate. The objective of this paper is to investigate various classification algorithms to predict the turnover of different companies based on the Stock price. The authorized dataset for predicting the turnover was taken from www.bsc.com and included the stock market values of various companies over the past 10 years. The algorithms were investigated using the "R" tool. The feature selection algorithm, Boruta, was run on this dataset to extract the important and influential features for classification. With these extracted features, the Total Turnover of the company was predicted using various classification algorithms like Random Forest, Decision Tree, SVM and Multinomial Regression. This prediction mechanism was implemented to predict the turnover of a company on an everyday basis and hence could help navigate through dubious stock market trades. An accuracy rate of 95% was achieved by the above prediction process. Moreover, the importance of stock market attributes was established as well.
[ { "version": "v1", "created": "Sat, 1 Aug 2015 06:50:01 GMT" } ]
2015-08-04T00:00:00
[ [ "Shashaank", "D. S.", "" ], [ "Sruthi", "V.", "" ], [ "Vijayalakshimi", "M. L. S", "" ], [ "Garcia", "Jacob Shomona", "" ] ]
TITLE: Turnover Prediction Of Shares using Data Mining techniques : A Case Study ABSTRACT: Predicting the turnover of a company in the ever fluctuating Stock market has always proved to be a precarious situation and most certainly a difficult task in hand. Data mining is a well-known sphere of Computer Science that aims on extracting meaningful information from large databases. However, despite the existence of many algorithms for the purpose of predicting the future trends, their efficiency is questionable as their predictions suffer from a high error rate. The objective of this paper is to investigate various classification algorithms to predict the turnover of different companies based on the Stock price. The authorized dataset for predicting the turnover was taken from www.bsc.com and included the stock market values of various companies over the past 10 years. The algorithms were investigated using the "R" tool. The feature selection algorithm, Boruta, was run on this dataset to extract the important and influential features for classification. With these extracted features, the Total Turnover of the company was predicted using various classification algorithms like Random Forest, Decision Tree, SVM and Multinomial Regression. This prediction mechanism was implemented to predict the turnover of a company on an everyday basis and hence could help navigate through dubious stock market trades. An accuracy rate of 95% was achieved by the above prediction process. Moreover, the importance of stock market attributes was established as well.
no_new_dataset
0.947817
1508.00092
Giovanni Poggi
Marco Castelluccio, Giovanni Poggi, Carlo Sansone, Luisa Verdoliva
Land Use Classification in Remote Sensing Images by Convolutional Neural Networks
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We explore the use of convolutional neural networks for the semantic classification of remote sensing scenes. Two recently proposed architectures, CaffeNet and GoogLeNet, are adopted, with three different learning modalities. Besides conventional training from scratch, we resort to pre-trained networks that are only fine-tuned on the target data, so as to avoid overfitting problems and reduce design time. Experiments on two remote sensing datasets, with markedly different characteristics, testify on the effectiveness and wide applicability of the proposed solution, which guarantees a significant performance improvement over all state-of-the-art references.
[ { "version": "v1", "created": "Sat, 1 Aug 2015 07:15:19 GMT" } ]
2015-08-04T00:00:00
[ [ "Castelluccio", "Marco", "" ], [ "Poggi", "Giovanni", "" ], [ "Sansone", "Carlo", "" ], [ "Verdoliva", "Luisa", "" ] ]
TITLE: Land Use Classification in Remote Sensing Images by Convolutional Neural Networks ABSTRACT: We explore the use of convolutional neural networks for the semantic classification of remote sensing scenes. Two recently proposed architectures, CaffeNet and GoogLeNet, are adopted, with three different learning modalities. Besides conventional training from scratch, we resort to pre-trained networks that are only fine-tuned on the target data, so as to avoid overfitting problems and reduce design time. Experiments on two remote sensing datasets, with markedly different characteristics, testify on the effectiveness and wide applicability of the proposed solution, which guarantees a significant performance improvement over all state-of-the-art references.
no_new_dataset
0.947721
1508.00192
Ling Chen
Ling Chen, Ting Yu, Rada Chirkova
WaveCluster with Differential Privacy
null
null
null
null
cs.DB
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
WaveCluster is an important family of grid-based clustering algorithms that are capable of finding clusters of arbitrary shapes. In this paper, we investigate techniques to perform WaveCluster while ensuring differential privacy. Our goal is to develop a general technique for achieving differential privacy on WaveCluster that accommodates different wavelet transforms. We show that straightforward techniques based on synthetic data generation and introduction of random noise when quantizing the data, though generally preserving the distribution of data, often introduce too much noise to preserve useful clusters. We then propose two optimized techniques, PrivTHR and PrivTHREM, which can significantly reduce data distortion during two key steps of WaveCluster: the quantization step and the significant grid identification step. We conduct extensive experiments based on four datasets that are particularly interesting in the context of clustering, and show that PrivTHR and PrivTHREM achieve high utility when privacy budgets are properly allocated.
[ { "version": "v1", "created": "Sun, 2 Aug 2015 04:41:51 GMT" } ]
2015-08-04T00:00:00
[ [ "Chen", "Ling", "" ], [ "Yu", "Ting", "" ], [ "Chirkova", "Rada", "" ] ]
TITLE: WaveCluster with Differential Privacy ABSTRACT: WaveCluster is an important family of grid-based clustering algorithms that are capable of finding clusters of arbitrary shapes. In this paper, we investigate techniques to perform WaveCluster while ensuring differential privacy. Our goal is to develop a general technique for achieving differential privacy on WaveCluster that accommodates different wavelet transforms. We show that straightforward techniques based on synthetic data generation and introduction of random noise when quantizing the data, though generally preserving the distribution of data, often introduce too much noise to preserve useful clusters. We then propose two optimized techniques, PrivTHR and PrivTHREM, which can significantly reduce data distortion during two key steps of WaveCluster: the quantization step and the significant grid identification step. We conduct extensive experiments based on four datasets that are particularly interesting in the context of clustering, and show that PrivTHR and PrivTHREM achieve high utility when privacy budgets are properly allocated.
no_new_dataset
0.952926
1508.00305
Panupong Pasupat
Panupong Pasupat, Percy Liang
Compositional Semantic Parsing on Semi-Structured Tables
null
null
null
null
cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Two important aspects of semantic parsing for question answering are the breadth of the knowledge source and the depth of logical compositionality. While existing work trades off one aspect for another, this paper simultaneously makes progress on both fronts through a new task: answering complex questions on semi-structured tables using question-answer pairs as supervision. The central challenge arises from two compounding factors: the broader domain results in an open-ended set of relations, and the deeper compositionality results in a combinatorial explosion in the space of logical forms. We propose a logical-form driven parsing algorithm guided by strong typing constraints and show that it obtains significant improvements over natural baselines. For evaluation, we created a new dataset of 22,033 complex questions on Wikipedia tables, which is made publicly available.
[ { "version": "v1", "created": "Mon, 3 Aug 2015 02:53:01 GMT" } ]
2015-08-04T00:00:00
[ [ "Pasupat", "Panupong", "" ], [ "Liang", "Percy", "" ] ]
TITLE: Compositional Semantic Parsing on Semi-Structured Tables ABSTRACT: Two important aspects of semantic parsing for question answering are the breadth of the knowledge source and the depth of logical compositionality. While existing work trades off one aspect for another, this paper simultaneously makes progress on both fronts through a new task: answering complex questions on semi-structured tables using question-answer pairs as supervision. The central challenge arises from two compounding factors: the broader domain results in an open-ended set of relations, and the deeper compositionality results in a combinatorial explosion in the space of logical forms. We propose a logical-form driven parsing algorithm guided by strong typing constraints and show that it obtains significant improvements over natural baselines. For evaluation, we created a new dataset of 22,033 complex questions on Wikipedia tables, which is made publicly available.
new_dataset
0.954393
1508.00307
Weilin Huang
Sheng Guo and Weilin Huang and Yu Qiao
Local Color Contrastive Descriptor for Image Classification
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Image representation and classification are two fundamental tasks towards multimedia content retrieval and understanding. The idea that shape and texture information (e.g. edge or orientation) are the key features for visual representation is ingrained and dominated in current multimedia and computer vision communities. A number of low-level features have been proposed by computing local gradients (e.g. SIFT, LBP and HOG), and have achieved great successes on numerous multimedia applications. In this paper, we present a simple yet efficient local descriptor for image classification, referred as Local Color Contrastive Descriptor (LCCD), by leveraging the neural mechanisms of color contrast. The idea originates from the observation in neural science that color and shape information are linked inextricably in visual cortical processing. The color contrast yields key information for visual color perception and provides strong linkage between color and shape. We propose a novel contrastive mechanism to compute the color contrast in both spatial location and multiple channels. The color contrast is computed by measuring \emph{f}-divergence between the color distributions of two regions. Our descriptor enriches local image representation with both color and contrast information. We verified experimentally that it can compensate strongly for the shape based descriptor (e.g. SIFT), while keeping computationally simple. Extensive experimental results on image classification show that our descriptor improves the performance of SIFT substantially by combinations, and achieves the state-of-the-art performance on three challenging benchmark datasets. It improves recent Deep Learning model (DeCAF) [1] largely from the accuracy of 40.94% to 49.68% in the large scale SUN397 database. Codes for the LCCD will be available.
[ { "version": "v1", "created": "Mon, 3 Aug 2015 03:29:50 GMT" } ]
2015-08-04T00:00:00
[ [ "Guo", "Sheng", "" ], [ "Huang", "Weilin", "" ], [ "Qiao", "Yu", "" ] ]
TITLE: Local Color Contrastive Descriptor for Image Classification ABSTRACT: Image representation and classification are two fundamental tasks towards multimedia content retrieval and understanding. The idea that shape and texture information (e.g. edge or orientation) are the key features for visual representation is ingrained and dominated in current multimedia and computer vision communities. A number of low-level features have been proposed by computing local gradients (e.g. SIFT, LBP and HOG), and have achieved great successes on numerous multimedia applications. In this paper, we present a simple yet efficient local descriptor for image classification, referred as Local Color Contrastive Descriptor (LCCD), by leveraging the neural mechanisms of color contrast. The idea originates from the observation in neural science that color and shape information are linked inextricably in visual cortical processing. The color contrast yields key information for visual color perception and provides strong linkage between color and shape. We propose a novel contrastive mechanism to compute the color contrast in both spatial location and multiple channels. The color contrast is computed by measuring \emph{f}-divergence between the color distributions of two regions. Our descriptor enriches local image representation with both color and contrast information. We verified experimentally that it can compensate strongly for the shape based descriptor (e.g. SIFT), while keeping computationally simple. Extensive experimental results on image classification show that our descriptor improves the performance of SIFT substantially by combinations, and achieves the state-of-the-art performance on three challenging benchmark datasets. It improves recent Deep Learning model (DeCAF) [1] largely from the accuracy of 40.94% to 49.68% in the large scale SUN397 database. Codes for the LCCD will be available.
no_new_dataset
0.950869
1508.00317
Roni Mittelman Roni Mittelman
Roni Mittelman
Time-series modeling with undecimated fully convolutional neural networks
null
null
null
null
stat.ML cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a new convolutional neural network-based time-series model. Typical convolutional neural network (CNN) architectures rely on the use of max-pooling operators in between layers, which leads to reduced resolution at the top layers. Instead, in this work we consider a fully convolutional network (FCN) architecture that uses causal filtering operations, and allows for the rate of the output signal to be the same as that of the input signal. We furthermore propose an undecimated version of the FCN, which we refer to as the undecimated fully convolutional neural network (UFCNN), and is motivated by the undecimated wavelet transform. Our experimental results verify that using the undecimated version of the FCN is necessary in order to allow for effective time-series modeling. The UFCNN has several advantages compared to other time-series models such as the recurrent neural network (RNN) and long short-term memory (LSTM), since it does not suffer from either the vanishing or exploding gradients problems, and is therefore easier to train. Convolution operations can also be implemented more efficiently compared to the recursion that is involved in RNN-based models. We evaluate the performance of our model in a synthetic target tracking task using bearing only measurements generated from a state-space model, a probabilistic modeling of polyphonic music sequences problem, and a high frequency trading task using a time-series of ask/bid quotes and their corresponding volumes. Our experimental results using synthetic and real datasets verify the significant advantages of the UFCNN compared to the RNN and LSTM baselines.
[ { "version": "v1", "created": "Mon, 3 Aug 2015 05:58:52 GMT" } ]
2015-08-04T00:00:00
[ [ "Mittelman", "Roni", "" ] ]
TITLE: Time-series modeling with undecimated fully convolutional neural networks ABSTRACT: We present a new convolutional neural network-based time-series model. Typical convolutional neural network (CNN) architectures rely on the use of max-pooling operators in between layers, which leads to reduced resolution at the top layers. Instead, in this work we consider a fully convolutional network (FCN) architecture that uses causal filtering operations, and allows for the rate of the output signal to be the same as that of the input signal. We furthermore propose an undecimated version of the FCN, which we refer to as the undecimated fully convolutional neural network (UFCNN), and is motivated by the undecimated wavelet transform. Our experimental results verify that using the undecimated version of the FCN is necessary in order to allow for effective time-series modeling. The UFCNN has several advantages compared to other time-series models such as the recurrent neural network (RNN) and long short-term memory (LSTM), since it does not suffer from either the vanishing or exploding gradients problems, and is therefore easier to train. Convolution operations can also be implemented more efficiently compared to the recursion that is involved in RNN-based models. We evaluate the performance of our model in a synthetic target tracking task using bearing only measurements generated from a state-space model, a probabilistic modeling of polyphonic music sequences problem, and a high frequency trading task using a time-series of ask/bid quotes and their corresponding volumes. Our experimental results using synthetic and real datasets verify the significant advantages of the UFCNN compared to the RNN and LSTM baselines.
no_new_dataset
0.952662
1508.00507
Tameem Adel
Tameem Adel, Alexander Wong, Daniel Stashuk
A Weakly Supervised Learning Approach based on Spectral Graph-Theoretic Grouping
Submitted to IEEE Access
null
null
null
cs.LG cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this study, a spectral graph-theoretic grouping strategy for weakly supervised classification is introduced, where a limited number of labelled samples and a larger set of unlabelled samples are used to construct a larger annotated training set composed of strongly labelled and weakly labelled samples. The inherent relationship between the set of strongly labelled samples and the set of unlabelled samples is established via spectral grouping, with the unlabelled samples subsequently weakly annotated based on the strongly labelled samples within the associated spectral groups. A number of similarity graph models for spectral grouping, including two new similarity graph models introduced in this study, are explored to investigate their performance in the context of weakly supervised classification in handling different types of data. Experimental results using benchmark datasets as well as real EMG datasets demonstrate that the proposed approach to weakly supervised classification can provide noticeable improvements in classification performance, and that the proposed similarity graph models can lead to ultimate learning results that are either better than or on a par with existing similarity graph models in the context of spectral grouping for weakly supervised classification.
[ { "version": "v1", "created": "Mon, 3 Aug 2015 18:08:04 GMT" } ]
2015-08-04T00:00:00
[ [ "Adel", "Tameem", "" ], [ "Wong", "Alexander", "" ], [ "Stashuk", "Daniel", "" ] ]
TITLE: A Weakly Supervised Learning Approach based on Spectral Graph-Theoretic Grouping ABSTRACT: In this study, a spectral graph-theoretic grouping strategy for weakly supervised classification is introduced, where a limited number of labelled samples and a larger set of unlabelled samples are used to construct a larger annotated training set composed of strongly labelled and weakly labelled samples. The inherent relationship between the set of strongly labelled samples and the set of unlabelled samples is established via spectral grouping, with the unlabelled samples subsequently weakly annotated based on the strongly labelled samples within the associated spectral groups. A number of similarity graph models for spectral grouping, including two new similarity graph models introduced in this study, are explored to investigate their performance in the context of weakly supervised classification in handling different types of data. Experimental results using benchmark datasets as well as real EMG datasets demonstrate that the proposed approach to weakly supervised classification can provide noticeable improvements in classification performance, and that the proposed similarity graph models can lead to ultimate learning results that are either better than or on a par with existing similarity graph models in the context of spectral grouping for weakly supervised classification.
no_new_dataset
0.951639
1508.00537
Rodrigo Nogueira
Rodrigo Frassetto Nogueira, Roberto de Alencar Lotufo, Rubens Campos Machado
Evaluating software-based fingerprint liveness detection using Convolutional Networks and Local Binary Patterns
arXiv admin note: text overlap with arXiv:1301.3557 by other authors
Biometric Measurements and Systems for Security and Medical Applications (BIOMS) Proceedings, 2014 IEEE Workshop on
10.1109/BIOMS.2014.6951531
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
With the growing use of biometric authentication systems in the past years, spoof fingerprint detection has become increasingly important. In this work, we implement and evaluate two different feature extraction techniques for software-based fingerprint liveness detection: Convolutional Networks with random weights and Local Binary Patterns. Both techniques were used in conjunction with a Support Vector Machine (SVM) classifier. Dataset Augmentation was used to increase classifier's performance and a variety of preprocessing operations were tested, such as frequency filtering, contrast equalization, and region of interest filtering. The experiments were made on the datasets used in The Liveness Detection Competition of years 2009, 2011 and 2013, which comprise almost 50,000 real and fake fingerprints' images. Our best method achieves an overall rate of 95.2% of correctly classified samples - an improvement of 35% in test error when compared with the best previously published results.
[ { "version": "v1", "created": "Mon, 3 Aug 2015 19:21:03 GMT" } ]
2015-08-04T00:00:00
[ [ "Nogueira", "Rodrigo Frassetto", "" ], [ "Lotufo", "Roberto de Alencar", "" ], [ "Machado", "Rubens Campos", "" ] ]
TITLE: Evaluating software-based fingerprint liveness detection using Convolutional Networks and Local Binary Patterns ABSTRACT: With the growing use of biometric authentication systems in the past years, spoof fingerprint detection has become increasingly important. In this work, we implement and evaluate two different feature extraction techniques for software-based fingerprint liveness detection: Convolutional Networks with random weights and Local Binary Patterns. Both techniques were used in conjunction with a Support Vector Machine (SVM) classifier. Dataset Augmentation was used to increase classifier's performance and a variety of preprocessing operations were tested, such as frequency filtering, contrast equalization, and region of interest filtering. The experiments were made on the datasets used in The Liveness Detection Competition of years 2009, 2011 and 2013, which comprise almost 50,000 real and fake fingerprints' images. Our best method achieves an overall rate of 95.2% of correctly classified samples - an improvement of 35% in test error when compared with the best previously published results.
no_new_dataset
0.955194
1502.01097
Gui-Song Xia
Jingwen Hu, Gui-Song Xia, Fan Hu, Liangpei Zhang
Dense v.s. Sparse: A Comparative Study of Sampling Analysis in Scene Classification of High-Resolution Remote Sensing Imagery
This paper has been withdrawn by the author due to the submission requirement of a journal
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Scene classification is a key problem in the interpretation of high-resolution remote sensing imagery. Many state-of-the-art methods, e.g. bag-of-visual-words model and its variants, the topic models as well as deep learning-based approaches, share similar procedures: patch sampling, feature description/learning and classification. Patch sampling is the first and a key procedure which has a great influence on the results. In the literature, many different sampling strategies have been used, {e.g. dense sampling, random sampling, keypoint-based sampling and saliency-based sampling, etc. However, it is still not clear which sampling strategy is suitable for the scene classification of high-resolution remote sensing images. In this paper, we comparatively study the effects of different sampling strategies under the scenario of scene classification of high-resolution remote sensing images. We divide the existing sampling methods into two types: dense sampling and sparse sampling, the later of which includes random sampling, keypoint-based sampling and various saliency-based sampling proposed recently. In order to compare their performances, we rely on a standard bag-of-visual-words model to construct our testing scheme, owing to their simplicity, robustness and efficiency. The experimental results on two commonly used datasets show that dense sampling has the best performance among all the strategies but with high spatial and computational complexity, random sampling gives better or comparable results than other sparse sampling methods, like the sophisticated multi-scale key-point operators and the saliency-based methods which are intensively studied and commonly used recently.
[ { "version": "v1", "created": "Wed, 4 Feb 2015 05:34:31 GMT" }, { "version": "v2", "created": "Fri, 31 Jul 2015 07:02:30 GMT" } ]
2015-08-03T00:00:00
[ [ "Hu", "Jingwen", "" ], [ "Xia", "Gui-Song", "" ], [ "Hu", "Fan", "" ], [ "Zhang", "Liangpei", "" ] ]
TITLE: Dense v.s. Sparse: A Comparative Study of Sampling Analysis in Scene Classification of High-Resolution Remote Sensing Imagery ABSTRACT: Scene classification is a key problem in the interpretation of high-resolution remote sensing imagery. Many state-of-the-art methods, e.g. bag-of-visual-words model and its variants, the topic models as well as deep learning-based approaches, share similar procedures: patch sampling, feature description/learning and classification. Patch sampling is the first and a key procedure which has a great influence on the results. In the literature, many different sampling strategies have been used, {e.g. dense sampling, random sampling, keypoint-based sampling and saliency-based sampling, etc. However, it is still not clear which sampling strategy is suitable for the scene classification of high-resolution remote sensing images. In this paper, we comparatively study the effects of different sampling strategies under the scenario of scene classification of high-resolution remote sensing images. We divide the existing sampling methods into two types: dense sampling and sparse sampling, the later of which includes random sampling, keypoint-based sampling and various saliency-based sampling proposed recently. In order to compare their performances, we rely on a standard bag-of-visual-words model to construct our testing scheme, owing to their simplicity, robustness and efficiency. The experimental results on two commonly used datasets show that dense sampling has the best performance among all the strategies but with high spatial and computational complexity, random sampling gives better or comparable results than other sparse sampling methods, like the sophisticated multi-scale key-point operators and the saliency-based methods which are intensively studied and commonly used recently.
no_new_dataset
0.953794
1507.08761
Amir Shahroudy
Amir Shahroudy, Gang Wang, Tian-Tsong Ng, Qingxiong Yang
Multimodal Multipart Learning for Action Recognition in Depth Videos
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The articulated and complex nature of human actions makes the task of action recognition difficult. One approach to handle this complexity is dividing it to the kinetics of body parts and analyzing the actions based on these partial descriptors. We propose a joint sparse regression based learning method which utilizes the structured sparsity to model each action as a combination of multimodal features from a sparse set of body parts. To represent dynamics and appearance of parts, we employ a heterogeneous set of depth and skeleton based features. The proper structure of multimodal multipart features are formulated into the learning framework via the proposed hierarchical mixed norm, to regularize the structured features of each part and to apply sparsity between them, in favor of a group feature selection. Our experimental results expose the effectiveness of the proposed learning method in which it outperforms other methods in all three tested datasets while saturating one of them by achieving perfect accuracy.
[ { "version": "v1", "created": "Fri, 31 Jul 2015 06:02:56 GMT" } ]
2015-08-03T00:00:00
[ [ "Shahroudy", "Amir", "" ], [ "Wang", "Gang", "" ], [ "Ng", "Tian-Tsong", "" ], [ "Yang", "Qingxiong", "" ] ]
TITLE: Multimodal Multipart Learning for Action Recognition in Depth Videos ABSTRACT: The articulated and complex nature of human actions makes the task of action recognition difficult. One approach to handle this complexity is dividing it to the kinetics of body parts and analyzing the actions based on these partial descriptors. We propose a joint sparse regression based learning method which utilizes the structured sparsity to model each action as a combination of multimodal features from a sparse set of body parts. To represent dynamics and appearance of parts, we employ a heterogeneous set of depth and skeleton based features. The proper structure of multimodal multipart features are formulated into the learning framework via the proposed hierarchical mixed norm, to regularize the structured features of each part and to apply sparsity between them, in favor of a group feature selection. Our experimental results expose the effectiveness of the proposed learning method in which it outperforms other methods in all three tested datasets while saturating one of them by achieving perfect accuracy.
no_new_dataset
0.944125
1409.3821
Andrea Montanari
Andrea Montanari
Computational Implications of Reducing Data to Sufficient Statistics
20 pages
null
null
null
stat.CO cs.IT cs.LG math.IT
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Given a large dataset and an estimation task, it is common to pre-process the data by reducing them to a set of sufficient statistics. This step is often regarded as straightforward and advantageous (in that it simplifies statistical analysis). I show that -on the contrary- reducing data to sufficient statistics can change a computationally tractable estimation problem into an intractable one. I discuss connections with recent work in theoretical computer science, and implications for some techniques to estimate graphical models.
[ { "version": "v1", "created": "Fri, 12 Sep 2014 18:57:01 GMT" }, { "version": "v2", "created": "Mon, 15 Sep 2014 16:39:26 GMT" }, { "version": "v3", "created": "Thu, 30 Jul 2015 19:35:44 GMT" } ]
2015-07-31T00:00:00
[ [ "Montanari", "Andrea", "" ] ]
TITLE: Computational Implications of Reducing Data to Sufficient Statistics ABSTRACT: Given a large dataset and an estimation task, it is common to pre-process the data by reducing them to a set of sufficient statistics. This step is often regarded as straightforward and advantageous (in that it simplifies statistical analysis). I show that -on the contrary- reducing data to sufficient statistics can change a computationally tractable estimation problem into an intractable one. I discuss connections with recent work in theoretical computer science, and implications for some techniques to estimate graphical models.
no_new_dataset
0.951051
1506.00711
Babak Saleh
Ahmed Elgammal and Babak Saleh
Quantifying Creativity in Art Networks
This paper will be published in the sixth International Conference on Computational Creativity (ICCC) June 29-July 2nd 2015, Park City, Utah, USA. This arXiv version is an extended version of the conference paper
null
null
null
cs.AI cs.CV cs.CY cs.MM cs.SI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Can we develop a computer algorithm that assesses the creativity of a painting given its context within art history? This paper proposes a novel computational framework for assessing the creativity of creative products, such as paintings, sculptures, poetry, etc. We use the most common definition of creativity, which emphasizes the originality of the product and its influential value. The proposed computational framework is based on constructing a network between creative products and using this network to infer about the originality and influence of its nodes. Through a series of transformations, we construct a Creativity Implication Network. We show that inference about creativity in this network reduces to a variant of network centrality problems which can be solved efficiently. We apply the proposed framework to the task of quantifying creativity of paintings (and sculptures). We experimented on two datasets with over 62K paintings to illustrate the behavior of the proposed framework. We also propose a methodology for quantitatively validating the results of the proposed algorithm, which we call the "time machine experiment".
[ { "version": "v1", "created": "Tue, 2 Jun 2015 00:20:54 GMT" } ]
2015-07-31T00:00:00
[ [ "Elgammal", "Ahmed", "" ], [ "Saleh", "Babak", "" ] ]
TITLE: Quantifying Creativity in Art Networks ABSTRACT: Can we develop a computer algorithm that assesses the creativity of a painting given its context within art history? This paper proposes a novel computational framework for assessing the creativity of creative products, such as paintings, sculptures, poetry, etc. We use the most common definition of creativity, which emphasizes the originality of the product and its influential value. The proposed computational framework is based on constructing a network between creative products and using this network to infer about the originality and influence of its nodes. Through a series of transformations, we construct a Creativity Implication Network. We show that inference about creativity in this network reduces to a variant of network centrality problems which can be solved efficiently. We apply the proposed framework to the task of quantifying creativity of paintings (and sculptures). We experimented on two datasets with over 62K paintings to illustrate the behavior of the proposed framework. We also propose a methodology for quantitatively validating the results of the proposed algorithm, which we call the "time machine experiment".
no_new_dataset
0.950503
1507.08286
David Held
David Held, Sebastian Thrun, Silvio Savarese
Deep Learning for Single-View Instance Recognition
16 pages, 15 figures
null
null
null
cs.CV cs.LG cs.NE cs.RO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Deep learning methods have typically been trained on large datasets in which many training examples are available. However, many real-world product datasets have only a small number of images available for each product. We explore the use of deep learning methods for recognizing object instances when we have only a single training example per class. We show that feedforward neural networks outperform state-of-the-art methods for recognizing objects from novel viewpoints even when trained from just a single image per object. To further improve our performance on this task, we propose to take advantage of a supplementary dataset in which we observe a separate set of objects from multiple viewpoints. We introduce a new approach for training deep learning methods for instance recognition with limited training data, in which we use an auxiliary multi-view dataset to train our network to be robust to viewpoint changes. We find that this approach leads to a more robust classifier for recognizing objects from novel viewpoints, outperforming previous state-of-the-art approaches including keypoint-matching, template-based techniques, and sparse coding.
[ { "version": "v1", "created": "Wed, 29 Jul 2015 20:11:12 GMT" } ]
2015-07-31T00:00:00
[ [ "Held", "David", "" ], [ "Thrun", "Sebastian", "" ], [ "Savarese", "Silvio", "" ] ]
TITLE: Deep Learning for Single-View Instance Recognition ABSTRACT: Deep learning methods have typically been trained on large datasets in which many training examples are available. However, many real-world product datasets have only a small number of images available for each product. We explore the use of deep learning methods for recognizing object instances when we have only a single training example per class. We show that feedforward neural networks outperform state-of-the-art methods for recognizing objects from novel viewpoints even when trained from just a single image per object. To further improve our performance on this task, we propose to take advantage of a supplementary dataset in which we observe a separate set of objects from multiple viewpoints. We introduce a new approach for training deep learning methods for instance recognition with limited training data, in which we use an auxiliary multi-view dataset to train our network to be robust to viewpoint changes. We find that this approach leads to a more robust classifier for recognizing objects from novel viewpoints, outperforming previous state-of-the-art approaches including keypoint-matching, template-based techniques, and sparse coding.
no_new_dataset
0.948202
1507.08363
Massimo Piccardi
Shaukat Abidi, Massimo Piccardi, Mary-Anne Williams
Action recognition in still images by latent superpixel classification
To appear in the Proceedings of the IEEE International Conference on Image Processing. Copyright 2015 IEEE. Please be aware of your obligations with respect to copyrighted material
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Action recognition from still images is an important task of computer vision applications such as image annotation, robotic navigation, video surveillance and several others. Existing approaches mainly rely on either bag-of-feature representations or articulated body-part models. However, the relationship between the action and the image segments is still substantially unexplored. For this reason, in this paper we propose to approach action recognition by leveraging an intermediate layer of "superpixels" whose latent classes can act as attributes of the action. In the proposed approach, the action class is predicted by a structural model(learnt by Latent Structural SVM) based on measurements from the image superpixels and their latent classes. Experimental results over the challenging Stanford 40 Actions dataset report a significant average accuracy of 74.06% for the positive class and 88.50% for the negative class, giving evidence to the performance of the proposed approach.
[ { "version": "v1", "created": "Thu, 30 Jul 2015 03:05:47 GMT" } ]
2015-07-31T00:00:00
[ [ "Abidi", "Shaukat", "" ], [ "Piccardi", "Massimo", "" ], [ "Williams", "Mary-Anne", "" ] ]
TITLE: Action recognition in still images by latent superpixel classification ABSTRACT: Action recognition from still images is an important task of computer vision applications such as image annotation, robotic navigation, video surveillance and several others. Existing approaches mainly rely on either bag-of-feature representations or articulated body-part models. However, the relationship between the action and the image segments is still substantially unexplored. For this reason, in this paper we propose to approach action recognition by leveraging an intermediate layer of "superpixels" whose latent classes can act as attributes of the action. In the proposed approach, the action class is predicted by a structural model(learnt by Latent Structural SVM) based on measurements from the image superpixels and their latent classes. Experimental results over the challenging Stanford 40 Actions dataset report a significant average accuracy of 74.06% for the positive class and 88.50% for the negative class, giving evidence to the performance of the proposed approach.
no_new_dataset
0.951142
1507.08373
Mehrtash Harandi
Mehrtash Harandi, Mathieu Salzmann, Fatih Porikli
When VLAD met Hilbert
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Vectors of Locally Aggregated Descriptors (VLAD) have emerged as powerful image/video representations that compete with or even outperform state-of-the-art approaches on many challenging visual recognition tasks. In this paper, we address two fundamental limitations of VLAD: its requirement for the local descriptors to have vector form and its restriction to linear classifiers due to its high-dimensionality. To this end, we introduce a kernelized version of VLAD. This not only lets us inherently exploit more sophisticated classification schemes, but also enables us to efficiently aggregate non-vector descriptors (e.g., tensors) in the VLAD framework. Furthermore, we propose three approximate formulations that allow us to accelerate the coding process while still benefiting from the properties of kernel VLAD. Our experiments demonstrate the effectiveness of our approach at handling manifold-valued data, such as covariance descriptors, on several classification tasks. Our results also evidence the benefits of our nonlinear VLAD descriptors against the linear ones in Euclidean space using several standard benchmark datasets.
[ { "version": "v1", "created": "Thu, 30 Jul 2015 04:17:02 GMT" } ]
2015-07-31T00:00:00
[ [ "Harandi", "Mehrtash", "" ], [ "Salzmann", "Mathieu", "" ], [ "Porikli", "Fatih", "" ] ]
TITLE: When VLAD met Hilbert ABSTRACT: Vectors of Locally Aggregated Descriptors (VLAD) have emerged as powerful image/video representations that compete with or even outperform state-of-the-art approaches on many challenging visual recognition tasks. In this paper, we address two fundamental limitations of VLAD: its requirement for the local descriptors to have vector form and its restriction to linear classifiers due to its high-dimensionality. To this end, we introduce a kernelized version of VLAD. This not only lets us inherently exploit more sophisticated classification schemes, but also enables us to efficiently aggregate non-vector descriptors (e.g., tensors) in the VLAD framework. Furthermore, we propose three approximate formulations that allow us to accelerate the coding process while still benefiting from the properties of kernel VLAD. Our experiments demonstrate the effectiveness of our approach at handling manifold-valued data, such as covariance descriptors, on several classification tasks. Our results also evidence the benefits of our nonlinear VLAD descriptors against the linear ones in Euclidean space using several standard benchmark datasets.
no_new_dataset
0.947672
1507.08429
Shuchang Zhou
Shuchang Zhou, Yuxin Wu
Multilinear Map Layer: Prediction Regularization by Structural Constraint
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we propose and study a technique to impose structural constraints on the output of a neural network, which can reduce amount of computation and number of parameters besides improving prediction accuracy when the output is known to approximately conform to the low-rankness prior. The technique proceeds by replacing the output layer of neural network with the so-called MLM layers, which forces the output to be the result of some Multilinear Map, like a hybrid-Kronecker-dot product or Kronecker Tensor Product. In particular, given an "autoencoder" model trained on SVHN dataset, we can construct a new model with MLM layer achieving 62\% reduction in total number of parameters and reduction of $\ell_2$ reconstruction error from 0.088 to 0.004. Further experiments on other autoencoder model variants trained on SVHN datasets also demonstrate the efficacy of MLM layers.
[ { "version": "v1", "created": "Thu, 30 Jul 2015 09:34:30 GMT" } ]
2015-07-31T00:00:00
[ [ "Zhou", "Shuchang", "" ], [ "Wu", "Yuxin", "" ] ]
TITLE: Multilinear Map Layer: Prediction Regularization by Structural Constraint ABSTRACT: In this paper we propose and study a technique to impose structural constraints on the output of a neural network, which can reduce amount of computation and number of parameters besides improving prediction accuracy when the output is known to approximately conform to the low-rankness prior. The technique proceeds by replacing the output layer of neural network with the so-called MLM layers, which forces the output to be the result of some Multilinear Map, like a hybrid-Kronecker-dot product or Kronecker Tensor Product. In particular, given an "autoencoder" model trained on SVHN dataset, we can construct a new model with MLM layer achieving 62\% reduction in total number of parameters and reduction of $\ell_2$ reconstruction error from 0.088 to 0.004. Further experiments on other autoencoder model variants trained on SVHN datasets also demonstrate the efficacy of MLM layers.
no_new_dataset
0.948346
1507.08445
Ankan Bansal
Ankan Bansal and K.S. Venkatesh
People Counting in High Density Crowds from Still Images
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a method of estimating the number of people in high density crowds from still images. The method estimates counts by fusing information from multiple sources. Most of the existing work on crowd counting deals with very small crowds (tens of individuals) and use temporal information from videos. Our method uses only still images to estimate the counts in high density images (hundreds to thousands of individuals). At this scale, we cannot rely on only one set of features for count estimation. We, therefore, use multiple sources, viz. interest points (SIFT), Fourier analysis, wavelet decomposition, GLCM features and low confidence head detections, to estimate the counts. Each of these sources gives a separate estimate of the count along with confidences and other statistical measures which are then combined to obtain the final estimate. We test our method on an existing dataset of fifty images containing over 64000 individuals. Further, we added another fifty annotated images of crowds and tested on the complete dataset of hundred images containing over 87000 individuals. The counts per image range from 81 to 4633. We report the performance in terms of mean absolute error, which is a measure of accuracy of the method, and mean normalised absolute error, which is a measure of the robustness.
[ { "version": "v1", "created": "Thu, 30 Jul 2015 10:47:31 GMT" } ]
2015-07-31T00:00:00
[ [ "Bansal", "Ankan", "" ], [ "Venkatesh", "K. S.", "" ] ]
TITLE: People Counting in High Density Crowds from Still Images ABSTRACT: We present a method of estimating the number of people in high density crowds from still images. The method estimates counts by fusing information from multiple sources. Most of the existing work on crowd counting deals with very small crowds (tens of individuals) and use temporal information from videos. Our method uses only still images to estimate the counts in high density images (hundreds to thousands of individuals). At this scale, we cannot rely on only one set of features for count estimation. We, therefore, use multiple sources, viz. interest points (SIFT), Fourier analysis, wavelet decomposition, GLCM features and low confidence head detections, to estimate the counts. Each of these sources gives a separate estimate of the count along with confidences and other statistical measures which are then combined to obtain the final estimate. We test our method on an existing dataset of fifty images containing over 64000 individuals. Further, we added another fifty annotated images of crowds and tested on the complete dataset of hundred images containing over 87000 individuals. The counts per image range from 81 to 4633. We report the performance in terms of mean absolute error, which is a measure of accuracy of the method, and mean normalised absolute error, which is a measure of the robustness.
new_dataset
0.893216
1501.04158
Niko S\"underhauf
Niko S\"underhauf, Feras Dayoub, Sareh Shirazi, Ben Upcroft, and Michael Milford
On the Performance of ConvNet Features for Place Recognition
null
null
null
null
cs.RO cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
After the incredible success of deep learning in the computer vision domain, there has been much interest in applying Convolutional Network (ConvNet) features in robotic fields such as visual navigation and SLAM. Unfortunately, there are fundamental differences and challenges involved. Computer vision datasets are very different in character to robotic camera data, real-time performance is essential, and performance priorities can be different. This paper comprehensively evaluates and compares the utility of three state-of-the-art ConvNets on the problems of particular relevance to navigation for robots; viewpoint-invariance and condition-invariance, and for the first time enables real-time place recognition performance using ConvNets with large maps by integrating a variety of existing (locality-sensitive hashing) and novel (semantic search space partitioning) optimization techniques. We present extensive experiments on four real world datasets cultivated to evaluate each of the specific challenges in place recognition. The results demonstrate that speed-ups of two orders of magnitude can be achieved with minimal accuracy degradation, enabling real-time performance. We confirm that networks trained for semantic place categorization also perform better at (specific) place recognition when faced with severe appearance changes and provide a reference for which networks and layers are optimal for different aspects of the place recognition problem.
[ { "version": "v1", "created": "Sat, 17 Jan 2015 05:16:12 GMT" }, { "version": "v2", "created": "Tue, 7 Jul 2015 11:35:10 GMT" }, { "version": "v3", "created": "Wed, 29 Jul 2015 01:56:54 GMT" } ]
2015-07-30T00:00:00
[ [ "Sünderhauf", "Niko", "" ], [ "Dayoub", "Feras", "" ], [ "Shirazi", "Sareh", "" ], [ "Upcroft", "Ben", "" ], [ "Milford", "Michael", "" ] ]
TITLE: On the Performance of ConvNet Features for Place Recognition ABSTRACT: After the incredible success of deep learning in the computer vision domain, there has been much interest in applying Convolutional Network (ConvNet) features in robotic fields such as visual navigation and SLAM. Unfortunately, there are fundamental differences and challenges involved. Computer vision datasets are very different in character to robotic camera data, real-time performance is essential, and performance priorities can be different. This paper comprehensively evaluates and compares the utility of three state-of-the-art ConvNets on the problems of particular relevance to navigation for robots; viewpoint-invariance and condition-invariance, and for the first time enables real-time place recognition performance using ConvNets with large maps by integrating a variety of existing (locality-sensitive hashing) and novel (semantic search space partitioning) optimization techniques. We present extensive experiments on four real world datasets cultivated to evaluate each of the specific challenges in place recognition. The results demonstrate that speed-ups of two orders of magnitude can be achieved with minimal accuracy degradation, enabling real-time performance. We confirm that networks trained for semantic place categorization also perform better at (specific) place recognition when faced with severe appearance changes and provide a reference for which networks and layers are optimal for different aspects of the place recognition problem.
no_new_dataset
0.947672
1502.06108
Xiao Lin
Xiao Lin, Devi Parikh
Don't Just Listen, Use Your Imagination: Leveraging Visual Common Sense for Non-Visual Tasks
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Artificial agents today can answer factual questions. But they fall short on questions that require common sense reasoning. Perhaps this is because most existing common sense databases rely on text to learn and represent knowledge. But much of common sense knowledge is unwritten - partly because it tends not to be interesting enough to talk about, and partly because some common sense is unnatural to articulate in text. While unwritten, it is not unseen. In this paper we leverage semantic common sense knowledge learned from images - i.e. visual common sense - in two textual tasks: fill-in-the-blank and visual paraphrasing. We propose to "imagine" the scene behind the text, and leverage visual cues from the "imagined" scenes in addition to textual cues while answering these questions. We imagine the scenes as a visual abstraction. Our approach outperforms a strong text-only baseline on these tasks. Our proposed tasks can serve as benchmarks to quantitatively evaluate progress in solving tasks that go "beyond recognition". Our code and datasets are publicly available.
[ { "version": "v1", "created": "Sat, 21 Feb 2015 15:25:40 GMT" }, { "version": "v2", "created": "Tue, 5 May 2015 18:54:05 GMT" }, { "version": "v3", "created": "Wed, 29 Jul 2015 03:04:19 GMT" } ]
2015-07-30T00:00:00
[ [ "Lin", "Xiao", "" ], [ "Parikh", "Devi", "" ] ]
TITLE: Don't Just Listen, Use Your Imagination: Leveraging Visual Common Sense for Non-Visual Tasks ABSTRACT: Artificial agents today can answer factual questions. But they fall short on questions that require common sense reasoning. Perhaps this is because most existing common sense databases rely on text to learn and represent knowledge. But much of common sense knowledge is unwritten - partly because it tends not to be interesting enough to talk about, and partly because some common sense is unnatural to articulate in text. While unwritten, it is not unseen. In this paper we leverage semantic common sense knowledge learned from images - i.e. visual common sense - in two textual tasks: fill-in-the-blank and visual paraphrasing. We propose to "imagine" the scene behind the text, and leverage visual cues from the "imagined" scenes in addition to textual cues while answering these questions. We imagine the scenes as a visual abstraction. Our approach outperforms a strong text-only baseline on these tasks. Our proposed tasks can serve as benchmarks to quantitatively evaluate progress in solving tasks that go "beyond recognition". Our code and datasets are publicly available.
no_new_dataset
0.943034
1506.04723
Ming-Yu Liu
Ming-Yu Liu, Shuoxin Lin, Srikumar Ramalingam, Oncel Tuzel
Layered Interpretation of Street View Images
The paper will be presented in the 2015 Robotics: Science and Systems Conference (RSS)
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a layered street view model to encode both depth and semantic information on street view images for autonomous driving. Recently, stixels, stix-mantics, and tiered scene labeling methods have been proposed to model street view images. We propose a 4-layer street view model, a compact representation over the recently proposed stix-mantics model. Our layers encode semantic classes like ground, pedestrians, vehicles, buildings, and sky in addition to the depths. The only input to our algorithm is a pair of stereo images. We use a deep neural network to extract the appearance features for semantic classes. We use a simple and an efficient inference algorithm to jointly estimate both semantic classes and layered depth values. Our method outperforms other competing approaches in Daimler urban scene segmentation dataset. Our algorithm is massively parallelizable, allowing a GPU implementation with a processing speed about 9 fps.
[ { "version": "v1", "created": "Mon, 15 Jun 2015 19:38:59 GMT" }, { "version": "v2", "created": "Wed, 29 Jul 2015 15:38:28 GMT" } ]
2015-07-30T00:00:00
[ [ "Liu", "Ming-Yu", "" ], [ "Lin", "Shuoxin", "" ], [ "Ramalingam", "Srikumar", "" ], [ "Tuzel", "Oncel", "" ] ]
TITLE: Layered Interpretation of Street View Images ABSTRACT: We propose a layered street view model to encode both depth and semantic information on street view images for autonomous driving. Recently, stixels, stix-mantics, and tiered scene labeling methods have been proposed to model street view images. We propose a 4-layer street view model, a compact representation over the recently proposed stix-mantics model. Our layers encode semantic classes like ground, pedestrians, vehicles, buildings, and sky in addition to the depths. The only input to our algorithm is a pair of stereo images. We use a deep neural network to extract the appearance features for semantic classes. We use a simple and an efficient inference algorithm to jointly estimate both semantic classes and layered depth values. Our method outperforms other competing approaches in Daimler urban scene segmentation dataset. Our algorithm is massively parallelizable, allowing a GPU implementation with a processing speed about 9 fps.
no_new_dataset
0.949716
1507.07242
Dayong Wang
Dayong Wang and Charles Otto and Anil K. Jain
Face Search at Scale: 80 Million Gallery
14 pages, 16 figures
null
null
MSU TECHNICAL REPORT MSU-CSE-15-11, JULY 24, 2015
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Due to the prevalence of social media websites, one challenge facing computer vision researchers is to devise methods to process and search for persons of interest among the billions of shared photos on these websites. Facebook revealed in a 2013 white paper that its users have uploaded more than 250 billion photos, and are uploading 350 million new photos each day. Due to this humongous amount of data, large-scale face search for mining web images is both important and challenging. Despite significant progress in face recognition, searching a large collection of unconstrained face images has not been adequately addressed. To address this challenge, we propose a face search system which combines a fast search procedure, coupled with a state-of-the-art commercial off the shelf (COTS) matcher, in a cascaded framework. Given a probe face, we first filter the large gallery of photos to find the top-k most similar faces using deep features generated from a convolutional neural network. The k candidates are re-ranked by combining similarities from deep features and the COTS matcher. We evaluate the proposed face search system on a gallery containing 80 million web-downloaded face images. Experimental results demonstrate that the deep features are competitive with state-of-the-art methods on unconstrained face recognition benchmarks (LFW and IJB-A). Further, the proposed face search system offers an excellent trade-off between accuracy and scalability on datasets consisting of millions of images. Additionally, in an experiment involving searching for face images of the Tsarnaev brothers, convicted of the Boston Marathon bombing, the proposed face search system could find the younger brother's (Dzhokhar Tsarnaev) photo at rank 1 in 1 second on a 5M gallery and at rank 8 in 7 seconds on an 80M gallery.
[ { "version": "v1", "created": "Sun, 26 Jul 2015 20:06:43 GMT" }, { "version": "v2", "created": "Tue, 28 Jul 2015 22:09:17 GMT" } ]
2015-07-30T00:00:00
[ [ "Wang", "Dayong", "" ], [ "Otto", "Charles", "" ], [ "Jain", "Anil K.", "" ] ]
TITLE: Face Search at Scale: 80 Million Gallery ABSTRACT: Due to the prevalence of social media websites, one challenge facing computer vision researchers is to devise methods to process and search for persons of interest among the billions of shared photos on these websites. Facebook revealed in a 2013 white paper that its users have uploaded more than 250 billion photos, and are uploading 350 million new photos each day. Due to this humongous amount of data, large-scale face search for mining web images is both important and challenging. Despite significant progress in face recognition, searching a large collection of unconstrained face images has not been adequately addressed. To address this challenge, we propose a face search system which combines a fast search procedure, coupled with a state-of-the-art commercial off the shelf (COTS) matcher, in a cascaded framework. Given a probe face, we first filter the large gallery of photos to find the top-k most similar faces using deep features generated from a convolutional neural network. The k candidates are re-ranked by combining similarities from deep features and the COTS matcher. We evaluate the proposed face search system on a gallery containing 80 million web-downloaded face images. Experimental results demonstrate that the deep features are competitive with state-of-the-art methods on unconstrained face recognition benchmarks (LFW and IJB-A). Further, the proposed face search system offers an excellent trade-off between accuracy and scalability on datasets consisting of millions of images. Additionally, in an experiment involving searching for face images of the Tsarnaev brothers, convicted of the Boston Marathon bombing, the proposed face search system could find the younger brother's (Dzhokhar Tsarnaev) photo at rank 1 in 1 second on a 5M gallery and at rank 8 in 7 seconds on an 80M gallery.
no_new_dataset
0.93835
1507.08030
Anthony Cazanoves Mr
Anthony Cazasnoves and Fanny Buyens and Sylvie Sevestre
Adapted sampling for 3D X-ray computed tomography
The 13th International Meeting on Fully Three-Dimensional Image Reconstruction in Radiology and Nuclear Medicine
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we introduce a method to build an adapted mesh representation of a 3D object for X-Ray tomography reconstruction. Using this representation, we provide means to reduce the computational cost of reconstruction by way of iterative algorithms. The adapted sampling of the reconstruction space is directly obtained from the projection dataset and prior to any reconstruction. It is built following two stages : firstly, 2D structural information is extracted from the projection images and is secondly merged in 3D to obtain a 3D pointcloud sampling the interfaces of the object. A relevant mesh is then built from this cloud by way of tetrahedralization. Critical parameters selections have been automatized through a statistical framework, thus avoiding dependence on users expertise. Applying this approach on geometrical shapes and on a 3D Shepp-Logan phantom, we show the relevance of such a sampling - obtained in a few seconds - and the drastic decrease in cells number to be estimated during reconstruction when compared to the usual regular voxel lattice. A first iterative reconstruction of the Shepp-Logan using this kind of sampling shows the relevant advantages in terms of low dose or sparse acquisition sampling contexts. The method can also prove useful for other applications such as finite element method computations.
[ { "version": "v1", "created": "Wed, 29 Jul 2015 06:30:04 GMT" } ]
2015-07-30T00:00:00
[ [ "Cazasnoves", "Anthony", "" ], [ "Buyens", "Fanny", "" ], [ "Sevestre", "Sylvie", "" ] ]
TITLE: Adapted sampling for 3D X-ray computed tomography ABSTRACT: In this paper, we introduce a method to build an adapted mesh representation of a 3D object for X-Ray tomography reconstruction. Using this representation, we provide means to reduce the computational cost of reconstruction by way of iterative algorithms. The adapted sampling of the reconstruction space is directly obtained from the projection dataset and prior to any reconstruction. It is built following two stages : firstly, 2D structural information is extracted from the projection images and is secondly merged in 3D to obtain a 3D pointcloud sampling the interfaces of the object. A relevant mesh is then built from this cloud by way of tetrahedralization. Critical parameters selections have been automatized through a statistical framework, thus avoiding dependence on users expertise. Applying this approach on geometrical shapes and on a 3D Shepp-Logan phantom, we show the relevance of such a sampling - obtained in a few seconds - and the drastic decrease in cells number to be estimated during reconstruction when compared to the usual regular voxel lattice. A first iterative reconstruction of the Shepp-Logan using this kind of sampling shows the relevant advantages in terms of low dose or sparse acquisition sampling contexts. The method can also prove useful for other applications such as finite element method computations.
no_new_dataset
0.945601
1507.08074
Sergey Novoselov
Sergey Novoselov, Alexandr Kozlov, Galina Lavrentyeva, Konstantin Simonchik, Vadim Shchemelinin
STC Anti-spoofing Systems for the ASVspoof 2015 Challenge
5 pages, 8 figures, 3 tables
null
null
null
cs.SD cs.LG stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper presents the Speech Technology Center (STC) systems submitted to Automatic Speaker Verification Spoofing and Countermeasures (ASVspoof) Challenge 2015. In this work we investigate different acoustic feature spaces to determine reliable and robust countermeasures against spoofing attacks. In addition to the commonly used front-end MFCC features we explored features derived from phase spectrum and features based on applying the multiresolution wavelet transform. Similar to state-of-the-art ASV systems, we used the standard TV-JFA approach for probability modelling in spoofing detection systems. Experiments performed on the development and evaluation datasets of the Challenge demonstrate that the use of phase-related and wavelet-based features provides a substantial input into the efficiency of the resulting STC systems. In our research we also focused on the comparison of the linear (SVM) and nonlinear (DBN) classifiers.
[ { "version": "v1", "created": "Wed, 29 Jul 2015 09:22:58 GMT" } ]
2015-07-30T00:00:00
[ [ "Novoselov", "Sergey", "" ], [ "Kozlov", "Alexandr", "" ], [ "Lavrentyeva", "Galina", "" ], [ "Simonchik", "Konstantin", "" ], [ "Shchemelinin", "Vadim", "" ] ]
TITLE: STC Anti-spoofing Systems for the ASVspoof 2015 Challenge ABSTRACT: This paper presents the Speech Technology Center (STC) systems submitted to Automatic Speaker Verification Spoofing and Countermeasures (ASVspoof) Challenge 2015. In this work we investigate different acoustic feature spaces to determine reliable and robust countermeasures against spoofing attacks. In addition to the commonly used front-end MFCC features we explored features derived from phase spectrum and features based on applying the multiresolution wavelet transform. Similar to state-of-the-art ASV systems, we used the standard TV-JFA approach for probability modelling in spoofing detection systems. Experiments performed on the development and evaluation datasets of the Challenge demonstrate that the use of phase-related and wavelet-based features provides a substantial input into the efficiency of the resulting STC systems. In our research we also focused on the comparison of the linear (SVM) and nonlinear (DBN) classifiers.
no_new_dataset
0.944587
1507.08104
Brian McWilliams
Barbora Micenkov\'a, Brian McWilliams, Ira Assent
Learning Representations for Outlier Detection on a Budget
null
null
null
null
cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The problem of detecting a small number of outliers in a large dataset is an important task in many fields from fraud detection to high-energy physics. Two approaches have emerged to tackle this problem: unsupervised and supervised. Supervised approaches require a sufficient amount of labeled data and are challenged by novel types of outliers and inherent class imbalance, whereas unsupervised methods do not take advantage of available labeled training examples and often exhibit poorer predictive performance. We propose BORE (a Bagged Outlier Representation Ensemble) which uses unsupervised outlier scoring functions (OSFs) as features in a supervised learning framework. BORE is able to adapt to arbitrary OSF feature representations, to the imbalance in labeled data as well as to prediction-time constraints on computational cost. We demonstrate the good performance of BORE compared to a variety of competing methods in the non-budgeted and the budgeted outlier detection problem on 12 real-world datasets.
[ { "version": "v1", "created": "Wed, 29 Jul 2015 11:28:41 GMT" } ]
2015-07-30T00:00:00
[ [ "Micenková", "Barbora", "" ], [ "McWilliams", "Brian", "" ], [ "Assent", "Ira", "" ] ]
TITLE: Learning Representations for Outlier Detection on a Budget ABSTRACT: The problem of detecting a small number of outliers in a large dataset is an important task in many fields from fraud detection to high-energy physics. Two approaches have emerged to tackle this problem: unsupervised and supervised. Supervised approaches require a sufficient amount of labeled data and are challenged by novel types of outliers and inherent class imbalance, whereas unsupervised methods do not take advantage of available labeled training examples and often exhibit poorer predictive performance. We propose BORE (a Bagged Outlier Representation Ensemble) which uses unsupervised outlier scoring functions (OSFs) as features in a supervised learning framework. BORE is able to adapt to arbitrary OSF feature representations, to the imbalance in labeled data as well as to prediction-time constraints on computational cost. We demonstrate the good performance of BORE compared to a variety of competing methods in the non-budgeted and the budgeted outlier detection problem on 12 real-world datasets.
no_new_dataset
0.947332
1507.08155
Teng Qiu
Teng Qiu, Yongjie Li
IT-Dendrogram: A New Member of the In-Tree (IT) Clustering Family
13 pages, 6 figures. IT-Dendrogram: An Effective Method to Visualize the In-Tree structure by Dendrogram
null
null
null
stat.ML cs.CV cs.LG stat.ME
http://creativecommons.org/licenses/by-nc-sa/4.0/
Previously, we proposed a physically-inspired method to construct data points into an effective in-tree (IT) structure, in which the underlying cluster structure in the dataset is well revealed. Although there are some edges in the IT structure requiring to be removed, such undesired edges are generally distinguishable from other edges and thus are easy to be determined. For instance, when the IT structures for the 2-dimensional (2D) datasets are graphically presented, those undesired edges can be easily spotted and interactively determined. However, in practice, there are many datasets that do not lie in the 2D Euclidean space, thus their IT structures cannot be graphically presented. But if we can effectively map those IT structures into a visualized space in which the salient features of those undesired edges are preserved, then the undesired edges in the IT structures can still be visually determined in a visualization environment. Previously, this purpose was reached by our method called IT-map. The outstanding advantage of IT-map is that clusters can still be found even with the so-called crowding problem in the embedding. In this paper, we propose another method, called IT-Dendrogram, to achieve the same goal through an effective combination of the IT structure and the single link hierarchical clustering (SLHC) method. Like IT-map, IT-Dendrogram can also effectively represent the IT structures in a visualization environment, whereas using another form, called the Dendrogram. IT-Dendrogram can serve as another visualization method to determine the undesired edges in the IT structures and thus benefit the IT-based clustering analysis. This was demonstrated on several datasets with different shapes, dimensions, and attributes. Unlike IT-map, IT-Dendrogram can always avoid the crowding problem, which could help users make more reliable cluster analysis in certain problems.
[ { "version": "v1", "created": "Wed, 29 Jul 2015 14:22:13 GMT" } ]
2015-07-30T00:00:00
[ [ "Qiu", "Teng", "" ], [ "Li", "Yongjie", "" ] ]
TITLE: IT-Dendrogram: A New Member of the In-Tree (IT) Clustering Family ABSTRACT: Previously, we proposed a physically-inspired method to construct data points into an effective in-tree (IT) structure, in which the underlying cluster structure in the dataset is well revealed. Although there are some edges in the IT structure requiring to be removed, such undesired edges are generally distinguishable from other edges and thus are easy to be determined. For instance, when the IT structures for the 2-dimensional (2D) datasets are graphically presented, those undesired edges can be easily spotted and interactively determined. However, in practice, there are many datasets that do not lie in the 2D Euclidean space, thus their IT structures cannot be graphically presented. But if we can effectively map those IT structures into a visualized space in which the salient features of those undesired edges are preserved, then the undesired edges in the IT structures can still be visually determined in a visualization environment. Previously, this purpose was reached by our method called IT-map. The outstanding advantage of IT-map is that clusters can still be found even with the so-called crowding problem in the embedding. In this paper, we propose another method, called IT-Dendrogram, to achieve the same goal through an effective combination of the IT structure and the single link hierarchical clustering (SLHC) method. Like IT-map, IT-Dendrogram can also effectively represent the IT structures in a visualization environment, whereas using another form, called the Dendrogram. IT-Dendrogram can serve as another visualization method to determine the undesired edges in the IT structures and thus benefit the IT-based clustering analysis. This was demonstrated on several datasets with different shapes, dimensions, and attributes. Unlike IT-map, IT-Dendrogram can always avoid the crowding problem, which could help users make more reliable cluster analysis in certain problems.
no_new_dataset
0.946001
1507.07508
Peng Sun
Peng Sun, Haoyin Zhou, Devon Lundine, James K. Min, Guanglei Xiong
Fast Segmentation of Left Ventricle in CT Images by Explicit Shape Regression using Random Pixel Difference Features
8 pages, link to a video demo
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recently, machine learning has been successfully applied to model-based left ventricle (LV) segmentation. The general framework involves two stages, which starts with LV localization and is followed by boundary delineation. Both are driven by supervised learning techniques. When compared to previous non-learning-based methods, several advantages have been shown, including full automation and improved accuracy. However, the speed is still slow, in the order of several seconds, for applications involving a large number of cases or case loads requiring real-time performance. In this paper, we propose a fast LV segmentation algorithm by joint localization and boundary delineation via training explicit shape regressor with random pixel difference features. Tested on 3D cardiac computed tomography (CT) image volumes, the average running time of the proposed algorithm is 1.2 milliseconds per case. On a dataset consisting of 139 CT volumes, a 5-fold cross validation shows the segmentation error is $1.21 \pm 0.11$ for LV endocardium and $1.23 \pm 0.11$ millimeters for epicardium. Compared with previous work, the proposed method is more stable (lower standard deviation) without significant compromise to the accuracy.
[ { "version": "v1", "created": "Mon, 27 Jul 2015 18:17:55 GMT" }, { "version": "v2", "created": "Tue, 28 Jul 2015 14:07:05 GMT" } ]
2015-07-29T00:00:00
[ [ "Sun", "Peng", "" ], [ "Zhou", "Haoyin", "" ], [ "Lundine", "Devon", "" ], [ "Min", "James K.", "" ], [ "Xiong", "Guanglei", "" ] ]
TITLE: Fast Segmentation of Left Ventricle in CT Images by Explicit Shape Regression using Random Pixel Difference Features ABSTRACT: Recently, machine learning has been successfully applied to model-based left ventricle (LV) segmentation. The general framework involves two stages, which starts with LV localization and is followed by boundary delineation. Both are driven by supervised learning techniques. When compared to previous non-learning-based methods, several advantages have been shown, including full automation and improved accuracy. However, the speed is still slow, in the order of several seconds, for applications involving a large number of cases or case loads requiring real-time performance. In this paper, we propose a fast LV segmentation algorithm by joint localization and boundary delineation via training explicit shape regressor with random pixel difference features. Tested on 3D cardiac computed tomography (CT) image volumes, the average running time of the proposed algorithm is 1.2 milliseconds per case. On a dataset consisting of 139 CT volumes, a 5-fold cross validation shows the segmentation error is $1.21 \pm 0.11$ for LV endocardium and $1.23 \pm 0.11$ millimeters for epicardium. Compared with previous work, the proposed method is more stable (lower standard deviation) without significant compromise to the accuracy.
no_new_dataset
0.946498
1507.07760
Konrad Simon
Konrad Simon, Sameer Sheorey, David Jacobs and Ronen Basri
A Hyperelastic Two-Scale Optimization Model for Shape Matching
null
null
null
null
cs.CG cs.CV cs.GR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We suggest a novel shape matching algorithm for three-dimensional surface meshes of disk or sphere topology. The method is based on the physical theory of nonlinear elasticity and can hence handle large rotations and deformations. Deformation boundary conditions that supplement the underlying equations are usually unknown. Given an initial guess, these are optimized such that the mechanical boundary forces that are responsible for the deformation are of a simple nature. We show a heuristic way to approximate the nonlinear optimization problem by a sequence of convex problems using finite elements. The deformation cost, i.e, the forces, is measured on a coarse scale while ICP-like matching is done on the fine scale. We demonstrate the plausibility of our algorithm on examples taken from different datasets.
[ { "version": "v1", "created": "Tue, 28 Jul 2015 13:27:51 GMT" } ]
2015-07-29T00:00:00
[ [ "Simon", "Konrad", "" ], [ "Sheorey", "Sameer", "" ], [ "Jacobs", "David", "" ], [ "Basri", "Ronen", "" ] ]
TITLE: A Hyperelastic Two-Scale Optimization Model for Shape Matching ABSTRACT: We suggest a novel shape matching algorithm for three-dimensional surface meshes of disk or sphere topology. The method is based on the physical theory of nonlinear elasticity and can hence handle large rotations and deformations. Deformation boundary conditions that supplement the underlying equations are usually unknown. Given an initial guess, these are optimized such that the mechanical boundary forces that are responsible for the deformation are of a simple nature. We show a heuristic way to approximate the nonlinear optimization problem by a sequence of convex problems using finite elements. The deformation cost, i.e, the forces, is measured on a coarse scale while ICP-like matching is done on the fine scale. We demonstrate the plausibility of our algorithm on examples taken from different datasets.
no_new_dataset
0.951278
1507.07815
Svebor Karaman
Giuseppe Lisanti and Svebor Karaman and Daniele Pezzatini and Alberto Del Bimbo
A Multi-Camera Image Processing and Visualization System for Train Safety Assessment
11 pages
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we present a machine vision system to efficiently monitor, analyze and present visual data acquired with a railway overhead gantry equipped with multiple cameras. This solution aims to improve the safety of daily life railway transportation in a two- fold manner: (1) by providing automatic algorithms that can process large imagery of trains (2) by helping train operators to keep attention on any possible malfunction. The system is designed with the latest cutting edge, high-rate visible and thermal cameras that ob- serve a train passing under an railway overhead gantry. The machine vision system is composed of three principal modules: (1) an automatic wagon identification system, recognizing the wagon ID according to the UIC classification of railway coaches; (2) a temperature monitoring system; (3) a system for the detection, localization and visualization of the pantograph of the train. These three machine vision modules process batch trains sequences and their resulting analysis are presented to an operator using a multitouch user interface. We detail all technical aspects of our multi-camera portal: the hardware requirements, the software developed to deal with the high-frame rate cameras and ensure reliable acquisition, the algorithms proposed to solve each computer vision task, and the multitouch interaction and visualization interface. We evaluate each component of our system on a dataset recorded in an ad-hoc railway test-bed, showing the potential of our proposed portal for train safety assessment.
[ { "version": "v1", "created": "Tue, 28 Jul 2015 15:36:24 GMT" } ]
2015-07-29T00:00:00
[ [ "Lisanti", "Giuseppe", "" ], [ "Karaman", "Svebor", "" ], [ "Pezzatini", "Daniele", "" ], [ "Del Bimbo", "Alberto", "" ] ]
TITLE: A Multi-Camera Image Processing and Visualization System for Train Safety Assessment ABSTRACT: In this paper we present a machine vision system to efficiently monitor, analyze and present visual data acquired with a railway overhead gantry equipped with multiple cameras. This solution aims to improve the safety of daily life railway transportation in a two- fold manner: (1) by providing automatic algorithms that can process large imagery of trains (2) by helping train operators to keep attention on any possible malfunction. The system is designed with the latest cutting edge, high-rate visible and thermal cameras that ob- serve a train passing under an railway overhead gantry. The machine vision system is composed of three principal modules: (1) an automatic wagon identification system, recognizing the wagon ID according to the UIC classification of railway coaches; (2) a temperature monitoring system; (3) a system for the detection, localization and visualization of the pantograph of the train. These three machine vision modules process batch trains sequences and their resulting analysis are presented to an operator using a multitouch user interface. We detail all technical aspects of our multi-camera portal: the hardware requirements, the software developed to deal with the high-frame rate cameras and ensure reliable acquisition, the algorithms proposed to solve each computer vision task, and the multitouch interaction and visualization interface. We evaluate each component of our system on a dataset recorded in an ad-hoc railway test-bed, showing the potential of our proposed portal for train safety assessment.
no_new_dataset
0.944995
1507.07882
Samarth Manoj Brahmbhatt
Samarth Brahmbhatt, Heni Ben Amor and Henrik Christensen
Occlusion-Aware Object Localization, Segmentation and Pose Estimation
British Machine Vision Conference 2015 (poster)
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a learning approach for localization and segmentation of objects in an image in a manner that is robust to partial occlusion. Our algorithm produces a bounding box around the full extent of the object and labels pixels in the interior that belong to the object. Like existing segmentation aware detection approaches, we learn an appearance model of the object and consider regions that do not fit this model as potential occlusions. However, in addition to the established use of pairwise potentials for encouraging local consistency, we use higher order potentials which capture information at the level of im- age segments. We also propose an efficient loss function that targets both localization and segmentation performance. Our algorithm achieves 13.52% segmentation error and 0.81 area under the false-positive per image vs. recall curve on average over the challenging CMU Kitchen Occlusion Dataset. This is a 42.44% decrease in segmentation error and a 16.13% increase in localization performance compared to the state-of-the-art. Finally, we show that the visibility labelling produced by our algorithm can make full 3D pose estimation from a single image robust to occlusion.
[ { "version": "v1", "created": "Mon, 27 Jul 2015 18:16:35 GMT" } ]
2015-07-29T00:00:00
[ [ "Brahmbhatt", "Samarth", "" ], [ "Amor", "Heni Ben", "" ], [ "Christensen", "Henrik", "" ] ]
TITLE: Occlusion-Aware Object Localization, Segmentation and Pose Estimation ABSTRACT: We present a learning approach for localization and segmentation of objects in an image in a manner that is robust to partial occlusion. Our algorithm produces a bounding box around the full extent of the object and labels pixels in the interior that belong to the object. Like existing segmentation aware detection approaches, we learn an appearance model of the object and consider regions that do not fit this model as potential occlusions. However, in addition to the established use of pairwise potentials for encouraging local consistency, we use higher order potentials which capture information at the level of im- age segments. We also propose an efficient loss function that targets both localization and segmentation performance. Our algorithm achieves 13.52% segmentation error and 0.81 area under the false-positive per image vs. recall curve on average over the challenging CMU Kitchen Occlusion Dataset. This is a 42.44% decrease in segmentation error and a 16.13% increase in localization performance compared to the state-of-the-art. Finally, we show that the visibility labelling produced by our algorithm can make full 3D pose estimation from a single image robust to occlusion.
no_new_dataset
0.946001
1507.07908
Luiz Capretz Dr.
Arif Raza, Luiz Fernando Capretz
Addressing User Requirements in Opens Source Software: The Role of Online Forums
null
Journal of Computing Science and Engineering, 8(1):57-63, 2014
null
null
cs.SE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
User satisfaction has always been important in the success of software, regardless of whether it is closed and proprietary or open source software (OSS). OSS users are geographically distributed and include technical as well as novice users. However, it is generally believed that if OSS was more usable, its popularity would increase tremendously. Hence, users and their requirements need to be addressed in the priorities of an OSS environment. Online public forums are a major medium of communication for the OSS community. The research model of this work studies the relationship between user requirements in open source software and online public forums. To conduct this research, we used a dataset consisting of 100 open source software projects in different categories. The results show that online forums play a significant role in identifying user requirements and addressing their requests in open source software.
[ { "version": "v1", "created": "Fri, 24 Jul 2015 15:48:05 GMT" } ]
2015-07-29T00:00:00
[ [ "Raza", "Arif", "" ], [ "Capretz", "Luiz Fernando", "" ] ]
TITLE: Addressing User Requirements in Opens Source Software: The Role of Online Forums ABSTRACT: User satisfaction has always been important in the success of software, regardless of whether it is closed and proprietary or open source software (OSS). OSS users are geographically distributed and include technical as well as novice users. However, it is generally believed that if OSS was more usable, its popularity would increase tremendously. Hence, users and their requirements need to be addressed in the priorities of an OSS environment. Online public forums are a major medium of communication for the OSS community. The research model of this work studies the relationship between user requirements in open source software and online public forums. To conduct this research, we used a dataset consisting of 100 open source software projects in different categories. The results show that online forums play a significant role in identifying user requirements and addressing their requests in open source software.
no_new_dataset
0.868437
1501.06202
Yanwei Fu
Yanwei Fu, Timothy M. Hospedales, Tao Xiang, Jiechao Xiong, Shaogang Gong, Yizhou Wang, and Yuan Yao
Robust Subjective Visual Property Prediction from Crowdsourced Pairwise Labels
14 pages, accepted by IEEE TPAMI
null
10.1109/TPAMI.2015.2456887
null
cs.CV cs.LG cs.MM cs.SI math.ST stat.TH
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The problem of estimating subjective visual properties from image and video has attracted increasing interest. A subjective visual property is useful either on its own (e.g. image and video interestingness) or as an intermediate representation for visual recognition (e.g. a relative attribute). Due to its ambiguous nature, annotating the value of a subjective visual property for learning a prediction model is challenging. To make the annotation more reliable, recent studies employ crowdsourcing tools to collect pairwise comparison labels because human annotators are much better at ranking two images/videos (e.g. which one is more interesting) than giving an absolute value to each of them separately. However, using crowdsourced data also introduces outliers. Existing methods rely on majority voting to prune the annotation outliers/errors. They thus require large amount of pairwise labels to be collected. More importantly as a local outlier detection method, majority voting is ineffective in identifying outliers that can cause global ranking inconsistencies. In this paper, we propose a more principled way to identify annotation outliers by formulating the subjective visual property prediction task as a unified robust learning to rank problem, tackling both the outlier detection and learning to rank jointly. Differing from existing methods, the proposed method integrates local pairwise comparison labels together to minimise a cost that corresponds to global inconsistency of ranking order. This not only leads to better detection of annotation outliers but also enables learning with extremely sparse annotations. Extensive experiments on various benchmark datasets demonstrate that our new approach significantly outperforms state-of-the-arts alternatives.
[ { "version": "v1", "created": "Sun, 25 Jan 2015 20:02:45 GMT" }, { "version": "v2", "created": "Fri, 30 Jan 2015 05:13:45 GMT" }, { "version": "v3", "created": "Fri, 24 Jul 2015 18:40:56 GMT" }, { "version": "v4", "created": "Mon, 27 Jul 2015 14:42:17 GMT" } ]
2015-07-28T00:00:00
[ [ "Fu", "Yanwei", "" ], [ "Hospedales", "Timothy M.", "" ], [ "Xiang", "Tao", "" ], [ "Xiong", "Jiechao", "" ], [ "Gong", "Shaogang", "" ], [ "Wang", "Yizhou", "" ], [ "Yao", "Yuan", "" ] ]
TITLE: Robust Subjective Visual Property Prediction from Crowdsourced Pairwise Labels ABSTRACT: The problem of estimating subjective visual properties from image and video has attracted increasing interest. A subjective visual property is useful either on its own (e.g. image and video interestingness) or as an intermediate representation for visual recognition (e.g. a relative attribute). Due to its ambiguous nature, annotating the value of a subjective visual property for learning a prediction model is challenging. To make the annotation more reliable, recent studies employ crowdsourcing tools to collect pairwise comparison labels because human annotators are much better at ranking two images/videos (e.g. which one is more interesting) than giving an absolute value to each of them separately. However, using crowdsourced data also introduces outliers. Existing methods rely on majority voting to prune the annotation outliers/errors. They thus require large amount of pairwise labels to be collected. More importantly as a local outlier detection method, majority voting is ineffective in identifying outliers that can cause global ranking inconsistencies. In this paper, we propose a more principled way to identify annotation outliers by formulating the subjective visual property prediction task as a unified robust learning to rank problem, tackling both the outlier detection and learning to rank jointly. Differing from existing methods, the proposed method integrates local pairwise comparison labels together to minimise a cost that corresponds to global inconsistency of ranking order. This not only leads to better detection of annotation outliers but also enables learning with extremely sparse annotations. Extensive experiments on various benchmark datasets demonstrate that our new approach significantly outperforms state-of-the-arts alternatives.
no_new_dataset
0.951953
1507.06763
Rina Okada
Rina Okada, Kazuto Fukuchi, Kazuya Kakizaki and Jun Sakuma
Differentially Private Analysis of Outliers
null
null
null
null
stat.ML cs.CR cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper investigates differentially private analysis of distance-based outliers. The problem of outlier detection is to find a small number of instances that are apparently distant from the remaining instances. On the other hand, the objective of differential privacy is to conceal presence (or absence) of any particular instance. Outlier detection and privacy protection are thus intrinsically conflicting tasks. In this paper, instead of reporting outliers detected, we present two types of differentially private queries that help to understand behavior of outliers. One is the query to count outliers, which reports the number of outliers that appear in a given subspace. Our formal analysis on the exact global sensitivity of outlier counts reveals that regular global sensitivity based method can make the outputs too noisy, particularly when the dimensionality of the given subspace is high. Noting that the counts of outliers are typically expected to be relatively small compared to the number of data, we introduce a mechanism based on the smooth upper bound of the local sensitivity. The other is the query to discovery top-$h$ subspaces containing a large number of outliers. This task can be naively achieved by issuing count queries to each subspace in turn. However, the variation of subspaces can grow exponentially in the data dimensionality. This can cause serious consumption of the privacy budget. For this task, we propose an exponential mechanism with a customized score function for subspace discovery. To the best of our knowledge, this study is the first trial to ensure differential privacy for distance-based outlier analysis. We demonstrated our methods with synthesized datasets and real datasets. The experimental results show that out method achieve better utility compared to the global sensitivity based methods.
[ { "version": "v1", "created": "Fri, 24 Jul 2015 07:30:49 GMT" }, { "version": "v2", "created": "Mon, 27 Jul 2015 02:19:15 GMT" } ]
2015-07-28T00:00:00
[ [ "Okada", "Rina", "" ], [ "Fukuchi", "Kazuto", "" ], [ "Kakizaki", "Kazuya", "" ], [ "Sakuma", "Jun", "" ] ]
TITLE: Differentially Private Analysis of Outliers ABSTRACT: This paper investigates differentially private analysis of distance-based outliers. The problem of outlier detection is to find a small number of instances that are apparently distant from the remaining instances. On the other hand, the objective of differential privacy is to conceal presence (or absence) of any particular instance. Outlier detection and privacy protection are thus intrinsically conflicting tasks. In this paper, instead of reporting outliers detected, we present two types of differentially private queries that help to understand behavior of outliers. One is the query to count outliers, which reports the number of outliers that appear in a given subspace. Our formal analysis on the exact global sensitivity of outlier counts reveals that regular global sensitivity based method can make the outputs too noisy, particularly when the dimensionality of the given subspace is high. Noting that the counts of outliers are typically expected to be relatively small compared to the number of data, we introduce a mechanism based on the smooth upper bound of the local sensitivity. The other is the query to discovery top-$h$ subspaces containing a large number of outliers. This task can be naively achieved by issuing count queries to each subspace in turn. However, the variation of subspaces can grow exponentially in the data dimensionality. This can cause serious consumption of the privacy budget. For this task, we propose an exponential mechanism with a customized score function for subspace discovery. To the best of our knowledge, this study is the first trial to ensure differential privacy for distance-based outlier analysis. We demonstrated our methods with synthesized datasets and real datasets. The experimental results show that out method achieve better utility compared to the global sensitivity based methods.
no_new_dataset
0.944995
1507.06692
Yasmen Wahba
Yasmen Wahba, Ehab ElSalamouny and Ghada ElTaweel
Improving the Performance of Multi-class Intrusion Detection Systems using Feature Reduction
null
null
null
null
cs.NI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Intrusion detection systems (IDS) are widely studied by researchers nowadays due to the dramatic growth in network-based technologies. Policy violations and unauthorized access is in turn increasing which makes intrusion detection systems of great importance. Existing approaches to improve intrusion detection systems focus on feature selection or reduction since some features are irrelevant or redundant which when removed improve the accuracy as well as the learning time. In this paper we propose a hybrid feature selection method using Correlation-based Feature Selection and Information Gain. In our work we apply adaptive boosting using na\"ive Bayes as the weak (base) classifier. The key point in our research is that we are able to improve the detection accuracy with a reduced number of features while precisely determining the attack. Experimental results showed that our proposed method achieved high accuracy compared to methods using only 5-class problem. Correlation is done using Greedy search strategy and na\"ive Bayes as the classifier on the reduced NSL-KDD dataset.
[ { "version": "v1", "created": "Thu, 23 Jul 2015 22:18:45 GMT" } ]
2015-07-27T00:00:00
[ [ "Wahba", "Yasmen", "" ], [ "ElSalamouny", "Ehab", "" ], [ "ElTaweel", "Ghada", "" ] ]
TITLE: Improving the Performance of Multi-class Intrusion Detection Systems using Feature Reduction ABSTRACT: Intrusion detection systems (IDS) are widely studied by researchers nowadays due to the dramatic growth in network-based technologies. Policy violations and unauthorized access is in turn increasing which makes intrusion detection systems of great importance. Existing approaches to improve intrusion detection systems focus on feature selection or reduction since some features are irrelevant or redundant which when removed improve the accuracy as well as the learning time. In this paper we propose a hybrid feature selection method using Correlation-based Feature Selection and Information Gain. In our work we apply adaptive boosting using na\"ive Bayes as the weak (base) classifier. The key point in our research is that we are able to improve the detection accuracy with a reduced number of features while precisely determining the attack. Experimental results showed that our proposed method achieved high accuracy compared to methods using only 5-class problem. Correlation is done using Greedy search strategy and na\"ive Bayes as the classifier on the reduced NSL-KDD dataset.
no_new_dataset
0.949389
1507.06802
Jesse Krijthe
Jesse H. Krijthe and Marco Loog
Implicitly Constrained Semi-Supervised Least Squares Classification
12 pages, 2 figures, 1 table. The Fourteenth International Symposium on Intelligent Data Analysis (2015), Saint-Etienne, France
null
null
null
stat.ML cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We introduce a novel semi-supervised version of the least squares classifier. This implicitly constrained least squares (ICLS) classifier minimizes the squared loss on the labeled data among the set of parameters implied by all possible labelings of the unlabeled data. Unlike other discriminative semi-supervised methods, our approach does not introduce explicit additional assumptions into the objective function, but leverages implicit assumptions already present in the choice of the supervised least squares classifier. We show this approach can be formulated as a quadratic programming problem and its solution can be found using a simple gradient descent procedure. We prove that, in a certain way, our method never leads to performance worse than the supervised classifier. Experimental results corroborate this theoretical result in the multidimensional case on benchmark datasets, also in terms of the error rate.
[ { "version": "v1", "created": "Fri, 24 Jul 2015 10:39:44 GMT" } ]
2015-07-27T00:00:00
[ [ "Krijthe", "Jesse H.", "" ], [ "Loog", "Marco", "" ] ]
TITLE: Implicitly Constrained Semi-Supervised Least Squares Classification ABSTRACT: We introduce a novel semi-supervised version of the least squares classifier. This implicitly constrained least squares (ICLS) classifier minimizes the squared loss on the labeled data among the set of parameters implied by all possible labelings of the unlabeled data. Unlike other discriminative semi-supervised methods, our approach does not introduce explicit additional assumptions into the objective function, but leverages implicit assumptions already present in the choice of the supervised least squares classifier. We show this approach can be formulated as a quadratic programming problem and its solution can be found using a simple gradient descent procedure. We prove that, in a certain way, our method never leads to performance worse than the supervised classifier. Experimental results corroborate this theoretical result in the multidimensional case on benchmark datasets, also in terms of the error rate.
no_new_dataset
0.948537
1507.06841
Jiawei Zhang
Jiawei Zhang, Philip S. Yu, Yuanhua Lv
Organizational Chart Inference
10 pages, 9 figures, 1 table. The paper is accepted by KDD 2015
null
null
null
cs.SI cs.CY
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Nowadays, to facilitate the communication and cooperation among employees, a new family of online social networks has been adopted in many companies, which are called the "enterprise social networks" (ESNs). ESNs can provide employees with various professional services to help them deal with daily work issues. Meanwhile, employees in companies are usually organized into different hierarchies according to the relative ranks of their positions. The company internal management structure can be outlined with the organizational chart visually, which is normally confidential to the public out of the privacy and security concerns. In this paper, we want to study the IOC (Inference of Organizational Chart) problem to identify company internal organizational chart based on the heterogeneous online ESN launched in it. IOC is very challenging to address as, to guarantee smooth operations, the internal organizational charts of companies need to meet certain structural requirements (about its depth and width). To solve the IOC problem, a novel unsupervised method Create (ChArT REcovEr) is proposed in this paper, which consists of 3 steps: (1) social stratification of ESN users into different social classes, (2) supervision link inference from managers to subordinates, and (3) consecutive social classes matching to prune the redundant supervision links. Extensive experiments conducted on real-world online ESN dataset demonstrate that Create can perform very well in addressing the IOC problem.
[ { "version": "v1", "created": "Fri, 24 Jul 2015 13:32:30 GMT" } ]
2015-07-27T00:00:00
[ [ "Zhang", "Jiawei", "" ], [ "Yu", "Philip S.", "" ], [ "Lv", "Yuanhua", "" ] ]
TITLE: Organizational Chart Inference ABSTRACT: Nowadays, to facilitate the communication and cooperation among employees, a new family of online social networks has been adopted in many companies, which are called the "enterprise social networks" (ESNs). ESNs can provide employees with various professional services to help them deal with daily work issues. Meanwhile, employees in companies are usually organized into different hierarchies according to the relative ranks of their positions. The company internal management structure can be outlined with the organizational chart visually, which is normally confidential to the public out of the privacy and security concerns. In this paper, we want to study the IOC (Inference of Organizational Chart) problem to identify company internal organizational chart based on the heterogeneous online ESN launched in it. IOC is very challenging to address as, to guarantee smooth operations, the internal organizational charts of companies need to meet certain structural requirements (about its depth and width). To solve the IOC problem, a novel unsupervised method Create (ChArT REcovEr) is proposed in this paper, which consists of 3 steps: (1) social stratification of ESN users into different social classes, (2) supervision link inference from managers to subordinates, and (3) consecutive social classes matching to prune the redundant supervision links. Extensive experiments conducted on real-world online ESN dataset demonstrate that Create can perform very well in addressing the IOC problem.
no_new_dataset
0.942188
1507.06927
Luiz Capretz Dr.
Faheem Ahmed, Piers Campbell, Ahmad Jaffar, Luiz Fernando Capretz
Myths and Realities about Online Forums in Open Source Software Development: An Empirical Study
null
The Open Software Engineering Journal, Volume 4, 52-63, 2010
10.2174/1875107X01004010052
null
cs.SE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The use of free and open source software (OSS) is gaining momentum due to the ever increasing availability and use of the Internet. Organizations are also now adopting open source software, despite some reservations, in particular regarding the provision and availability of support. Some of the biggest concerns about free and open source software are post release software defects and their rectification, management of dynamic requirements and support to the users. A common belief is that there is no appropriate support available for this class of software. A contradictory argument is that due to the active involvement of Internet users in online forums, there is in fact a large resource available that communicates and manages the provision of support. The research model of this empirical investigation examines the evidence available to assess whether this commonly held belief is based on facts given the current developments in OSS or simply a myth, which has developed around OSS development. We analyzed a dataset consisting of 1880 open source software projects covering a broad range of categories in this investigation. The results show that online forums play a significant role in managing software defects, implementation of new requirements and providing support to the users in open source software and have become a major source of assistance in maintenance of the open source projects.
[ { "version": "v1", "created": "Fri, 24 Jul 2015 17:39:03 GMT" } ]
2015-07-27T00:00:00
[ [ "Ahmed", "Faheem", "" ], [ "Campbell", "Piers", "" ], [ "Jaffar", "Ahmad", "" ], [ "Capretz", "Luiz Fernando", "" ] ]
TITLE: Myths and Realities about Online Forums in Open Source Software Development: An Empirical Study ABSTRACT: The use of free and open source software (OSS) is gaining momentum due to the ever increasing availability and use of the Internet. Organizations are also now adopting open source software, despite some reservations, in particular regarding the provision and availability of support. Some of the biggest concerns about free and open source software are post release software defects and their rectification, management of dynamic requirements and support to the users. A common belief is that there is no appropriate support available for this class of software. A contradictory argument is that due to the active involvement of Internet users in online forums, there is in fact a large resource available that communicates and manages the provision of support. The research model of this empirical investigation examines the evidence available to assess whether this commonly held belief is based on facts given the current developments in OSS or simply a myth, which has developed around OSS development. We analyzed a dataset consisting of 1880 open source software projects covering a broad range of categories in this investigation. The results show that online forums play a significant role in managing software defects, implementation of new requirements and providing support to the users in open source software and have become a major source of assistance in maintenance of the open source projects.
no_new_dataset
0.906653
1202.4044
Michael McCoy
Gilad Lerman, Michael McCoy, Joel A. Tropp, and Teng Zhang
Robust computation of linear models by convex relaxation
Formerly titled "Robust computation of linear models, or How to find a needle in a haystack"
Foundations of Computational Mathematics, April 2015, Volume 15, Issue 2, pp 363-410
10.1007/s10208-014-9221-0
null
cs.IT math.IT stat.CO stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Consider a dataset of vector-valued observations that consists of noisy inliers, which are explained well by a low-dimensional subspace, along with some number of outliers. This work describes a convex optimization problem, called REAPER, that can reliably fit a low-dimensional model to this type of data. This approach parameterizes linear subspaces using orthogonal projectors, and it uses a relaxation of the set of orthogonal projectors to reach the convex formulation. The paper provides an efficient algorithm for solving the REAPER problem, and it documents numerical experiments which confirm that REAPER can dependably find linear structure in synthetic and natural data. In addition, when the inliers lie near a low-dimensional subspace, there is a rigorous theory that describes when REAPER can approximate this subspace.
[ { "version": "v1", "created": "Sat, 18 Feb 2012 00:47:22 GMT" }, { "version": "v2", "created": "Mon, 11 Aug 2014 19:19:28 GMT" } ]
2015-07-24T00:00:00
[ [ "Lerman", "Gilad", "" ], [ "McCoy", "Michael", "" ], [ "Tropp", "Joel A.", "" ], [ "Zhang", "Teng", "" ] ]
TITLE: Robust computation of linear models by convex relaxation ABSTRACT: Consider a dataset of vector-valued observations that consists of noisy inliers, which are explained well by a low-dimensional subspace, along with some number of outliers. This work describes a convex optimization problem, called REAPER, that can reliably fit a low-dimensional model to this type of data. This approach parameterizes linear subspaces using orthogonal projectors, and it uses a relaxation of the set of orthogonal projectors to reach the convex formulation. The paper provides an efficient algorithm for solving the REAPER problem, and it documents numerical experiments which confirm that REAPER can dependably find linear structure in synthetic and natural data. In addition, when the inliers lie near a low-dimensional subspace, there is a rigorous theory that describes when REAPER can approximate this subspace.
no_new_dataset
0.93196
1505.00393
Francesco Visin
Francesco Visin and Kyle Kastner and Kyunghyun Cho and Matteo Matteucci and Aaron Courville and Yoshua Bengio
ReNet: A Recurrent Neural Network Based Alternative to Convolutional Networks
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we propose a deep neural network architecture for object recognition based on recurrent neural networks. The proposed network, called ReNet, replaces the ubiquitous convolution+pooling layer of the deep convolutional neural network with four recurrent neural networks that sweep horizontally and vertically in both directions across the image. We evaluate the proposed ReNet on three widely-used benchmark datasets; MNIST, CIFAR-10 and SVHN. The result suggests that ReNet is a viable alternative to the deep convolutional neural network, and that further investigation is needed.
[ { "version": "v1", "created": "Sun, 3 May 2015 04:58:53 GMT" }, { "version": "v2", "created": "Fri, 3 Jul 2015 11:31:53 GMT" }, { "version": "v3", "created": "Thu, 23 Jul 2015 17:11:04 GMT" } ]
2015-07-24T00:00:00
[ [ "Visin", "Francesco", "" ], [ "Kastner", "Kyle", "" ], [ "Cho", "Kyunghyun", "" ], [ "Matteucci", "Matteo", "" ], [ "Courville", "Aaron", "" ], [ "Bengio", "Yoshua", "" ] ]
TITLE: ReNet: A Recurrent Neural Network Based Alternative to Convolutional Networks ABSTRACT: In this paper, we propose a deep neural network architecture for object recognition based on recurrent neural networks. The proposed network, called ReNet, replaces the ubiquitous convolution+pooling layer of the deep convolutional neural network with four recurrent neural networks that sweep horizontally and vertically in both directions across the image. We evaluate the proposed ReNet on three widely-used benchmark datasets; MNIST, CIFAR-10 and SVHN. The result suggests that ReNet is a viable alternative to the deep convolutional neural network, and that further investigation is needed.
no_new_dataset
0.9549
1506.07310
Jingtuo Liu
Jingtuo Liu and Yafeng Deng and Tao Bai and Zhengping Wei and Chang Huang
Targeting Ultimate Accuracy: Face Recognition via Deep Embedding
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Face Recognition has been studied for many decades. As opposed to traditional hand-crafted features such as LBP and HOG, much more sophisticated features can be learned automatically by deep learning methods in a data-driven way. In this paper, we propose a two-stage approach that combines a multi-patch deep CNN and deep metric learning, which extracts low dimensional but very discriminative features for face verification and recognition. Experiments show that this method outperforms other state-of-the-art methods on LFW dataset, achieving 99.77% pair-wise verification accuracy and significantly better accuracy under other two more practical protocols. This paper also discusses the importance of data size and the number of patches, showing a clear path to practical high-performance face recognition systems in real world.
[ { "version": "v1", "created": "Wed, 24 Jun 2015 10:36:26 GMT" }, { "version": "v2", "created": "Thu, 25 Jun 2015 03:05:20 GMT" }, { "version": "v3", "created": "Fri, 26 Jun 2015 03:05:45 GMT" }, { "version": "v4", "created": "Thu, 23 Jul 2015 02:34:29 GMT" } ]
2015-07-24T00:00:00
[ [ "Liu", "Jingtuo", "" ], [ "Deng", "Yafeng", "" ], [ "Bai", "Tao", "" ], [ "Wei", "Zhengping", "" ], [ "Huang", "Chang", "" ] ]
TITLE: Targeting Ultimate Accuracy: Face Recognition via Deep Embedding ABSTRACT: Face Recognition has been studied for many decades. As opposed to traditional hand-crafted features such as LBP and HOG, much more sophisticated features can be learned automatically by deep learning methods in a data-driven way. In this paper, we propose a two-stage approach that combines a multi-patch deep CNN and deep metric learning, which extracts low dimensional but very discriminative features for face verification and recognition. Experiments show that this method outperforms other state-of-the-art methods on LFW dataset, achieving 99.77% pair-wise verification accuracy and significantly better accuracy under other two more practical protocols. This paper also discusses the importance of data size and the number of patches, showing a clear path to practical high-performance face recognition systems in real world.
no_new_dataset
0.952486
1507.06429
Albert Gordo
Albert Gordo and Adrien Gaidon and Florent Perronnin
Deep Fishing: Gradient Features from Deep Nets
To appear at BMVC 2015
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Convolutional Networks (ConvNets) have recently improved image recognition performance thanks to end-to-end learning of deep feed-forward models from raw pixels. Deep learning is a marked departure from the previous state of the art, the Fisher Vector (FV), which relied on gradient-based encoding of local hand-crafted features. In this paper, we discuss a novel connection between these two approaches. First, we show that one can derive gradient representations from ConvNets in a similar fashion to the FV. Second, we show that this gradient representation actually corresponds to a structured matrix that allows for efficient similarity computation. We experimentally study the benefits of transferring this representation over the outputs of ConvNet layers, and find consistent improvements on the Pascal VOC 2007 and 2012 datasets.
[ { "version": "v1", "created": "Thu, 23 Jul 2015 10:01:45 GMT" } ]
2015-07-24T00:00:00
[ [ "Gordo", "Albert", "" ], [ "Gaidon", "Adrien", "" ], [ "Perronnin", "Florent", "" ] ]
TITLE: Deep Fishing: Gradient Features from Deep Nets ABSTRACT: Convolutional Networks (ConvNets) have recently improved image recognition performance thanks to end-to-end learning of deep feed-forward models from raw pixels. Deep learning is a marked departure from the previous state of the art, the Fisher Vector (FV), which relied on gradient-based encoding of local hand-crafted features. In this paper, we discuss a novel connection between these two approaches. First, we show that one can derive gradient representations from ConvNets in a similar fashion to the FV. Second, we show that this gradient representation actually corresponds to a structured matrix that allows for efficient similarity computation. We experimentally study the benefits of transferring this representation over the outputs of ConvNet layers, and find consistent improvements on the Pascal VOC 2007 and 2012 datasets.
no_new_dataset
0.949763
1507.06452
Amin Mantrach
Robin Devooght and Nicolas Kourtellis and Amin Mantrach
Dynamic Matrix Factorization with Priors on Unknown Values
in the Proceedings of 21st ACM SIGKDD Conference on Knowledge Discovery and Data Mining 2015
null
null
null
stat.ML cs.IR cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Advanced and effective collaborative filtering methods based on explicit feedback assume that unknown ratings do not follow the same model as the observed ones (\emph{not missing at random}). In this work, we build on this assumption, and introduce a novel dynamic matrix factorization framework that allows to set an explicit prior on unknown values. When new ratings, users, or items enter the system, we can update the factorization in time independent of the size of data (number of users, items and ratings). Hence, we can quickly recommend items even to very recent users. We test our methods on three large datasets, including two very sparse ones, in static and dynamic conditions. In each case, we outrank state-of-the-art matrix factorization methods that do not use a prior on unknown ratings.
[ { "version": "v1", "created": "Thu, 23 Jul 2015 11:39:58 GMT" } ]
2015-07-24T00:00:00
[ [ "Devooght", "Robin", "" ], [ "Kourtellis", "Nicolas", "" ], [ "Mantrach", "Amin", "" ] ]
TITLE: Dynamic Matrix Factorization with Priors on Unknown Values ABSTRACT: Advanced and effective collaborative filtering methods based on explicit feedback assume that unknown ratings do not follow the same model as the observed ones (\emph{not missing at random}). In this work, we build on this assumption, and introduce a novel dynamic matrix factorization framework that allows to set an explicit prior on unknown values. When new ratings, users, or items enter the system, we can update the factorization in time independent of the size of data (number of users, items and ratings). Hence, we can quickly recommend items even to very recent users. We test our methods on three large datasets, including two very sparse ones, in static and dynamic conditions. In each case, we outrank state-of-the-art matrix factorization methods that do not use a prior on unknown ratings.
no_new_dataset
0.949012
1507.06477
Takayuki Mizuno
Takayuki Mizuno, Takaaki Ohnishi, Tsutomu Watanabe
Novel and topical business news and their impact on stock market activities
8 pages, 6 figures, 2 tables
null
null
null
q-fin.ST cs.CY physics.soc-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose an indicator to measure the degree to which a particular news article is novel, as well as an indicator to measure the degree to which a particular news item attracts attention from investors. The novelty measure is obtained by comparing the extent to which a particular news article is similar to earlier news articles, and an article is regarded as novel if there was no similar article before it. On the other hand, we say a news item receives a lot of attention and thus is highly topical if it is simultaneously reported by many news agencies and read by many investors who receive news from those agencies. The topicality measure for a news item is obtained by counting the number of news articles whose content is similar to an original news article but which are delivered by other news agencies. To check the performance of the indicators, we empirically examine how these indicators are correlated with intraday financial market indicators such as the number of transactions and price volatility. Specifically, we use a dataset consisting of over 90 million business news articles reported in English and a dataset consisting of minute-by-minute stock prices on the New York Stock Exchange and the NASDAQ Stock Market from 2003 to 2014, and show that stock prices and transaction volumes exhibited a significant response to a news article when it is novel and topical.
[ { "version": "v1", "created": "Thu, 23 Jul 2015 12:54:35 GMT" } ]
2015-07-24T00:00:00
[ [ "Mizuno", "Takayuki", "" ], [ "Ohnishi", "Takaaki", "" ], [ "Watanabe", "Tsutomu", "" ] ]
TITLE: Novel and topical business news and their impact on stock market activities ABSTRACT: We propose an indicator to measure the degree to which a particular news article is novel, as well as an indicator to measure the degree to which a particular news item attracts attention from investors. The novelty measure is obtained by comparing the extent to which a particular news article is similar to earlier news articles, and an article is regarded as novel if there was no similar article before it. On the other hand, we say a news item receives a lot of attention and thus is highly topical if it is simultaneously reported by many news agencies and read by many investors who receive news from those agencies. The topicality measure for a news item is obtained by counting the number of news articles whose content is similar to an original news article but which are delivered by other news agencies. To check the performance of the indicators, we empirically examine how these indicators are correlated with intraday financial market indicators such as the number of transactions and price volatility. Specifically, we use a dataset consisting of over 90 million business news articles reported in English and a dataset consisting of minute-by-minute stock prices on the New York Stock Exchange and the NASDAQ Stock Market from 2003 to 2014, and show that stock prices and transaction volumes exhibited a significant response to a news article when it is novel and topical.
new_dataset
0.967132
1411.2749
Tobias Kuhn
Tobias Kuhn, Christine Chichester, Michael Krauthammer, Michel Dumontier
Publishing without Publishers: a Decentralized Approach to Dissemination, Retrieval, and Archiving of Data
In Proceedings of the 14th International Semantic Web Conference (ISWC) 2015
null
null
null
cs.DL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Making available and archiving scientific results is for the most part still considered the task of classical publishing companies, despite the fact that classical forms of publishing centered around printed narrative articles no longer seem well-suited in the digital age. In particular, there exist currently no efficient, reliable, and agreed-upon methods for publishing scientific datasets, which have become increasingly important for science. Here we propose to design scientific data publishing as a Web-based bottom-up process, without top-down control of central authorities such as publishing companies. Based on a novel combination of existing concepts and technologies, we present a server network to decentrally store and archive data in the form of nanopublications, an RDF-based format to represent scientific data. We show how this approach allows researchers to publish, retrieve, verify, and recombine datasets of nanopublications in a reliable and trustworthy manner, and we argue that this architecture could be used for the Semantic Web in general. Evaluation of the current small network shows that this system is efficient and reliable.
[ { "version": "v1", "created": "Tue, 11 Nov 2014 10:09:15 GMT" }, { "version": "v2", "created": "Wed, 22 Jul 2015 08:25:11 GMT" } ]
2015-07-23T00:00:00
[ [ "Kuhn", "Tobias", "" ], [ "Chichester", "Christine", "" ], [ "Krauthammer", "Michael", "" ], [ "Dumontier", "Michel", "" ] ]
TITLE: Publishing without Publishers: a Decentralized Approach to Dissemination, Retrieval, and Archiving of Data ABSTRACT: Making available and archiving scientific results is for the most part still considered the task of classical publishing companies, despite the fact that classical forms of publishing centered around printed narrative articles no longer seem well-suited in the digital age. In particular, there exist currently no efficient, reliable, and agreed-upon methods for publishing scientific datasets, which have become increasingly important for science. Here we propose to design scientific data publishing as a Web-based bottom-up process, without top-down control of central authorities such as publishing companies. Based on a novel combination of existing concepts and technologies, we present a server network to decentrally store and archive data in the form of nanopublications, an RDF-based format to represent scientific data. We show how this approach allows researchers to publish, retrieve, verify, and recombine datasets of nanopublications in a reliable and trustworthy manner, and we argue that this architecture could be used for the Semantic Web in general. Evaluation of the current small network shows that this system is efficient and reliable.
no_new_dataset
0.944536
1506.05869
Oriol Vinyals
Oriol Vinyals, Quoc Le
A Neural Conversational Model
ICML Deep Learning Workshop 2015
null
null
null
cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Conversational modeling is an important task in natural language understanding and machine intelligence. Although previous approaches exist, they are often restricted to specific domains (e.g., booking an airline ticket) and require hand-crafted rules. In this paper, we present a simple approach for this task which uses the recently proposed sequence to sequence framework. Our model converses by predicting the next sentence given the previous sentence or sentences in a conversation. The strength of our model is that it can be trained end-to-end and thus requires much fewer hand-crafted rules. We find that this straightforward model can generate simple conversations given a large conversational training dataset. Our preliminary results suggest that, despite optimizing the wrong objective function, the model is able to converse well. It is able extract knowledge from both a domain specific dataset, and from a large, noisy, and general domain dataset of movie subtitles. On a domain-specific IT helpdesk dataset, the model can find a solution to a technical problem via conversations. On a noisy open-domain movie transcript dataset, the model can perform simple forms of common sense reasoning. As expected, we also find that the lack of consistency is a common failure mode of our model.
[ { "version": "v1", "created": "Fri, 19 Jun 2015 02:52:23 GMT" }, { "version": "v2", "created": "Tue, 23 Jun 2015 22:12:47 GMT" }, { "version": "v3", "created": "Wed, 22 Jul 2015 03:29:47 GMT" } ]
2015-07-23T00:00:00
[ [ "Vinyals", "Oriol", "" ], [ "Le", "Quoc", "" ] ]
TITLE: A Neural Conversational Model ABSTRACT: Conversational modeling is an important task in natural language understanding and machine intelligence. Although previous approaches exist, they are often restricted to specific domains (e.g., booking an airline ticket) and require hand-crafted rules. In this paper, we present a simple approach for this task which uses the recently proposed sequence to sequence framework. Our model converses by predicting the next sentence given the previous sentence or sentences in a conversation. The strength of our model is that it can be trained end-to-end and thus requires much fewer hand-crafted rules. We find that this straightforward model can generate simple conversations given a large conversational training dataset. Our preliminary results suggest that, despite optimizing the wrong objective function, the model is able to converse well. It is able extract knowledge from both a domain specific dataset, and from a large, noisy, and general domain dataset of movie subtitles. On a domain-specific IT helpdesk dataset, the model can find a solution to a technical problem via conversations. On a noisy open-domain movie transcript dataset, the model can perform simple forms of common sense reasoning. As expected, we also find that the lack of consistency is a common failure mode of our model.
no_new_dataset
0.941815
1507.05775
Shuchang Zhou
Shuchang Zhou, Jia-Nan Wu
Compression of Fully-Connected Layer in Neural Network by Kronecker Product
null
null
null
null
cs.NE cs.CV cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we propose and study a technique to reduce the number of parameters and computation time in fully-connected layers of neural networks using Kronecker product, at a mild cost of the prediction quality. The technique proceeds by replacing Fully-Connected layers with so-called Kronecker Fully-Connected layers, where the weight matrices of the FC layers are approximated by linear combinations of multiple Kronecker products of smaller matrices. In particular, given a model trained on SVHN dataset, we are able to construct a new KFC model with 73\% reduction in total number of parameters, while the error only rises mildly. In contrast, using low-rank method can only achieve 35\% reduction in total number of parameters given similar quality degradation allowance. If we only compare the KFC layer with its counterpart fully-connected layer, the reduction in the number of parameters exceeds 99\%. The amount of computation is also reduced as we replace matrix product of the large matrices in FC layers with matrix products of a few smaller matrices in KFC layers. Further experiments on MNIST, SVHN and some Chinese Character recognition models also demonstrate effectiveness of our technique.
[ { "version": "v1", "created": "Tue, 21 Jul 2015 10:29:11 GMT" }, { "version": "v2", "created": "Wed, 22 Jul 2015 11:59:08 GMT" } ]
2015-07-23T00:00:00
[ [ "Zhou", "Shuchang", "" ], [ "Wu", "Jia-Nan", "" ] ]
TITLE: Compression of Fully-Connected Layer in Neural Network by Kronecker Product ABSTRACT: In this paper we propose and study a technique to reduce the number of parameters and computation time in fully-connected layers of neural networks using Kronecker product, at a mild cost of the prediction quality. The technique proceeds by replacing Fully-Connected layers with so-called Kronecker Fully-Connected layers, where the weight matrices of the FC layers are approximated by linear combinations of multiple Kronecker products of smaller matrices. In particular, given a model trained on SVHN dataset, we are able to construct a new KFC model with 73\% reduction in total number of parameters, while the error only rises mildly. In contrast, using low-rank method can only achieve 35\% reduction in total number of parameters given similar quality degradation allowance. If we only compare the KFC layer with its counterpart fully-connected layer, the reduction in the number of parameters exceeds 99\%. The amount of computation is also reduced as we replace matrix product of the large matrices in FC layers with matrix products of a few smaller matrices in KFC layers. Further experiments on MNIST, SVHN and some Chinese Character recognition models also demonstrate effectiveness of our technique.
no_new_dataset
0.951639
1501.07873
Yongxin Yang
Qian Yu, Yongxin Yang, Yi-Zhe Song, Tao Xiang and Timothy Hospedales
Sketch-a-Net that Beats Humans
Accepted to BMVC 2015 (oral)
null
null
null
cs.CV cs.NE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a multi-scale multi-channel deep neural network framework that, for the first time, yields sketch recognition performance surpassing that of humans. Our superior performance is a result of explicitly embedding the unique characteristics of sketches in our model: (i) a network architecture designed for sketch rather than natural photo statistics, (ii) a multi-channel generalisation that encodes sequential ordering in the sketching process, and (iii) a multi-scale network ensemble with joint Bayesian fusion that accounts for the different levels of abstraction exhibited in free-hand sketches. We show that state-of-the-art deep networks specifically engineered for photos of natural objects fail to perform well on sketch recognition, regardless whether they are trained using photo or sketch. Our network on the other hand not only delivers the best performance on the largest human sketch dataset to date, but also is small in size making efficient training possible using just CPUs.
[ { "version": "v1", "created": "Fri, 30 Jan 2015 18:35:59 GMT" }, { "version": "v2", "created": "Wed, 27 May 2015 18:59:06 GMT" }, { "version": "v3", "created": "Tue, 21 Jul 2015 15:59:05 GMT" } ]
2015-07-22T00:00:00
[ [ "Yu", "Qian", "" ], [ "Yang", "Yongxin", "" ], [ "Song", "Yi-Zhe", "" ], [ "Xiang", "Tao", "" ], [ "Hospedales", "Timothy", "" ] ]
TITLE: Sketch-a-Net that Beats Humans ABSTRACT: We propose a multi-scale multi-channel deep neural network framework that, for the first time, yields sketch recognition performance surpassing that of humans. Our superior performance is a result of explicitly embedding the unique characteristics of sketches in our model: (i) a network architecture designed for sketch rather than natural photo statistics, (ii) a multi-channel generalisation that encodes sequential ordering in the sketching process, and (iii) a multi-scale network ensemble with joint Bayesian fusion that accounts for the different levels of abstraction exhibited in free-hand sketches. We show that state-of-the-art deep networks specifically engineered for photos of natural objects fail to perform well on sketch recognition, regardless whether they are trained using photo or sketch. Our network on the other hand not only delivers the best performance on the largest human sketch dataset to date, but also is small in size making efficient training possible using just CPUs.
no_new_dataset
0.951233
1503.00688
Zhilin Zhang
Zhilin Zhang
Photoplethysmography-Based Heart Rate Monitoring in Physical Activities via Joint Sparse Spectrum Reconstruction
Published in IEEE Transactions on Biomedical Engineering, Vol. 62, No. 8, PP. 1902-1910, August 2015
IEEE Transactions on Biomedical Engineering, Vol. 62, No. 8, PP. 1902-1910, August 2015
10.1109/TBME.2015.2406332
null
cs.OH cs.CY stat.AP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Goal: A new method for heart rate monitoring using photoplethysmography (PPG) during physical activities is proposed. Methods: It jointly estimates spectra of PPG signals and simultaneous acceleration signals, utilizing the multiple measurement vector model in sparse signal recovery. Due to a common sparsity constraint on spectral coefficients, the method can easily identify and remove spectral peaks of motion artifact (MA) in PPG spectra. Thus, it does not need any extra signal processing modular to remove MA as in some other algorithms. Furthermore, seeking spectral peaks associated with heart rate is simplified. Results: Experimental results on 12 PPG datasets sampled at 25 Hz and recorded during subjects' fast running showed that it had high performance. The average absolute estimation error was 1.28 beat per minute and the standard deviation was 2.61 beat per minute. Conclusion and Significance: These results show that the method has great potential to be used for PPG-based heart rate monitoring in wearable devices for fitness tracking and health monitoring.
[ { "version": "v1", "created": "Sat, 21 Feb 2015 01:48:20 GMT" }, { "version": "v2", "created": "Tue, 21 Jul 2015 06:21:23 GMT" } ]
2015-07-22T00:00:00
[ [ "Zhang", "Zhilin", "" ] ]
TITLE: Photoplethysmography-Based Heart Rate Monitoring in Physical Activities via Joint Sparse Spectrum Reconstruction ABSTRACT: Goal: A new method for heart rate monitoring using photoplethysmography (PPG) during physical activities is proposed. Methods: It jointly estimates spectra of PPG signals and simultaneous acceleration signals, utilizing the multiple measurement vector model in sparse signal recovery. Due to a common sparsity constraint on spectral coefficients, the method can easily identify and remove spectral peaks of motion artifact (MA) in PPG spectra. Thus, it does not need any extra signal processing modular to remove MA as in some other algorithms. Furthermore, seeking spectral peaks associated with heart rate is simplified. Results: Experimental results on 12 PPG datasets sampled at 25 Hz and recorded during subjects' fast running showed that it had high performance. The average absolute estimation error was 1.28 beat per minute and the standard deviation was 2.61 beat per minute. Conclusion and Significance: These results show that the method has great potential to be used for PPG-based heart rate monitoring in wearable devices for fitness tracking and health monitoring.
no_new_dataset
0.945801
1507.05717
Cong Yao
Baoguang Shi and Xiang Bai and Cong Yao
An End-to-End Trainable Neural Network for Image-based Sequence Recognition and Its Application to Scene Text Recognition
5 figures
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Image-based sequence recognition has been a long-standing research topic in computer vision. In this paper, we investigate the problem of scene text recognition, which is among the most important and challenging tasks in image-based sequence recognition. A novel neural network architecture, which integrates feature extraction, sequence modeling and transcription into a unified framework, is proposed. Compared with previous systems for scene text recognition, the proposed architecture possesses four distinctive properties: (1) It is end-to-end trainable, in contrast to most of the existing algorithms whose components are separately trained and tuned. (2) It naturally handles sequences in arbitrary lengths, involving no character segmentation or horizontal scale normalization. (3) It is not confined to any predefined lexicon and achieves remarkable performances in both lexicon-free and lexicon-based scene text recognition tasks. (4) It generates an effective yet much smaller model, which is more practical for real-world application scenarios. The experiments on standard benchmarks, including the IIIT-5K, Street View Text and ICDAR datasets, demonstrate the superiority of the proposed algorithm over the prior arts. Moreover, the proposed algorithm performs well in the task of image-based music score recognition, which evidently verifies the generality of it.
[ { "version": "v1", "created": "Tue, 21 Jul 2015 06:26:32 GMT" } ]
2015-07-22T00:00:00
[ [ "Shi", "Baoguang", "" ], [ "Bai", "Xiang", "" ], [ "Yao", "Cong", "" ] ]
TITLE: An End-to-End Trainable Neural Network for Image-based Sequence Recognition and Its Application to Scene Text Recognition ABSTRACT: Image-based sequence recognition has been a long-standing research topic in computer vision. In this paper, we investigate the problem of scene text recognition, which is among the most important and challenging tasks in image-based sequence recognition. A novel neural network architecture, which integrates feature extraction, sequence modeling and transcription into a unified framework, is proposed. Compared with previous systems for scene text recognition, the proposed architecture possesses four distinctive properties: (1) It is end-to-end trainable, in contrast to most of the existing algorithms whose components are separately trained and tuned. (2) It naturally handles sequences in arbitrary lengths, involving no character segmentation or horizontal scale normalization. (3) It is not confined to any predefined lexicon and achieves remarkable performances in both lexicon-free and lexicon-based scene text recognition tasks. (4) It generates an effective yet much smaller model, which is more practical for real-world application scenarios. The experiments on standard benchmarks, including the IIIT-5K, Street View Text and ICDAR datasets, demonstrate the superiority of the proposed algorithm over the prior arts. Moreover, the proposed algorithm performs well in the task of image-based music score recognition, which evidently verifies the generality of it.
no_new_dataset
0.951051
1507.05860
Naoshi Tobita
Naoshi Tobita, Shunsuke Honda, Kazuhiko Hara, Wataru Aoyagi, Yasuo Arai, Toshinobu Miyoshi, Ikuo Kurachi, Takaki Hatsui, Togo Kudo, Kazuo Kobayashi
Compensation for TID Damage in SOI Pixel Devices
null
null
null
null
physics.ins-det
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We are investigating adaption of SOI pixel devices for future high energy physic(HEP) experiments. The pixel sensors are required to be operational in very severe radiation environment. Most challenging issue in the adoption is the TID (total ionizing dose) damage where holes trapped in oxide layers affect the operation of nearby transistors. We have introduced a second SOI layer - SOI2 beneath the BOX (Buried OXide) layer - in order to compensate for the TID effect by applying a negative voltage to this electrode to cancel the effect caused by accumulated positive holes. In this paper, the TID effects caused by Co gamma-ray irradiation are presented based on the transistor characteristics measurements. The irradiation was carried out in various biasing conditions to investigate hole accumulation dependence on the potential configurations. We also compare the data with samples irradiated with X-ray. Since we observed a fair agreement between the two irradiation datasets, the TID effects have been investigated in a wide dose range from 100~Gy to 2~MGy.
[ { "version": "v1", "created": "Tue, 21 Jul 2015 14:49:13 GMT" } ]
2015-07-22T00:00:00
[ [ "Tobita", "Naoshi", "" ], [ "Honda", "Shunsuke", "" ], [ "Hara", "Kazuhiko", "" ], [ "Aoyagi", "Wataru", "" ], [ "Arai", "Yasuo", "" ], [ "Miyoshi", "Toshinobu", "" ], [ "Kurachi", "Ikuo", "" ], [ "Hatsui", "Takaki", "" ], [ "Kudo", "Togo", "" ], [ "Kobayashi", "Kazuo", "" ] ]
TITLE: Compensation for TID Damage in SOI Pixel Devices ABSTRACT: We are investigating adaption of SOI pixel devices for future high energy physic(HEP) experiments. The pixel sensors are required to be operational in very severe radiation environment. Most challenging issue in the adoption is the TID (total ionizing dose) damage where holes trapped in oxide layers affect the operation of nearby transistors. We have introduced a second SOI layer - SOI2 beneath the BOX (Buried OXide) layer - in order to compensate for the TID effect by applying a negative voltage to this electrode to cancel the effect caused by accumulated positive holes. In this paper, the TID effects caused by Co gamma-ray irradiation are presented based on the transistor characteristics measurements. The irradiation was carried out in various biasing conditions to investigate hole accumulation dependence on the potential configurations. We also compare the data with samples irradiated with X-ray. Since we observed a fair agreement between the two irradiation datasets, the TID effects have been investigated in a wide dose range from 100~Gy to 2~MGy.
no_new_dataset
0.946843
1411.7718
Dacheng Tao
Tongliang Liu and Dacheng Tao
Classification with Noisy Labels by Importance Reweighting
null
null
10.1109/TPAMI.2015.2456899
null
stat.ML cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we study a classification problem in which sample labels are randomly corrupted. In this scenario, there is an unobservable sample with noise-free labels. However, before being observed, the true labels are independently flipped with a probability $\rho\in[0,0.5)$, and the random label noise can be class-conditional. Here, we address two fundamental problems raised by this scenario. The first is how to best use the abundant surrogate loss functions designed for the traditional classification problem when there is label noise. We prove that any surrogate loss function can be used for classification with noisy labels by using importance reweighting, with consistency assurance that the label noise does not ultimately hinder the search for the optimal classifier of the noise-free sample. The other is the open problem of how to obtain the noise rate $\rho$. We show that the rate is upper bounded by the conditional probability $P(y|x)$ of the noisy sample. Consequently, the rate can be estimated, because the upper bound can be easily reached in classification problems. Experimental results on synthetic and real datasets confirm the efficiency of our methods.
[ { "version": "v1", "created": "Thu, 27 Nov 2014 23:18:51 GMT" }, { "version": "v2", "created": "Sat, 18 Jul 2015 04:03:44 GMT" } ]
2015-07-21T00:00:00
[ [ "Liu", "Tongliang", "" ], [ "Tao", "Dacheng", "" ] ]
TITLE: Classification with Noisy Labels by Importance Reweighting ABSTRACT: In this paper, we study a classification problem in which sample labels are randomly corrupted. In this scenario, there is an unobservable sample with noise-free labels. However, before being observed, the true labels are independently flipped with a probability $\rho\in[0,0.5)$, and the random label noise can be class-conditional. Here, we address two fundamental problems raised by this scenario. The first is how to best use the abundant surrogate loss functions designed for the traditional classification problem when there is label noise. We prove that any surrogate loss function can be used for classification with noisy labels by using importance reweighting, with consistency assurance that the label noise does not ultimately hinder the search for the optimal classifier of the noise-free sample. The other is the open problem of how to obtain the noise rate $\rho$. We show that the rate is upper bounded by the conditional probability $P(y|x)$ of the noisy sample. Consequently, the rate can be estimated, because the upper bound can be easily reached in classification problems. Experimental results on synthetic and real datasets confirm the efficiency of our methods.
no_new_dataset
0.941007
1501.00102
Natalia Neverova
Natalia Neverova and Christian Wolf and Graham W. Taylor and Florian Nebout
ModDrop: adaptive multi-modal gesture recognition
14 pages, 7 figures
null
null
null
cs.CV cs.HC cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a method for gesture detection and localisation based on multi-scale and multi-modal deep learning. Each visual modality captures spatial information at a particular spatial scale (such as motion of the upper body or a hand), and the whole system operates at three temporal scales. Key to our technique is a training strategy which exploits: i) careful initialization of individual modalities; and ii) gradual fusion involving random dropping of separate channels (dubbed ModDrop) for learning cross-modality correlations while preserving uniqueness of each modality-specific representation. We present experiments on the ChaLearn 2014 Looking at People Challenge gesture recognition track, in which we placed first out of 17 teams. Fusing multiple modalities at several spatial and temporal scales leads to a significant increase in recognition rates, allowing the model to compensate for errors of the individual classifiers as well as noise in the separate channels. Futhermore, the proposed ModDrop training technique ensures robustness of the classifier to missing signals in one or several channels to produce meaningful predictions from any number of available modalities. In addition, we demonstrate the applicability of the proposed fusion scheme to modalities of arbitrary nature by experiments on the same dataset augmented with audio.
[ { "version": "v1", "created": "Wed, 31 Dec 2014 09:55:43 GMT" }, { "version": "v2", "created": "Sat, 6 Jun 2015 14:46:33 GMT" } ]
2015-07-21T00:00:00
[ [ "Neverova", "Natalia", "" ], [ "Wolf", "Christian", "" ], [ "Taylor", "Graham W.", "" ], [ "Nebout", "Florian", "" ] ]
TITLE: ModDrop: adaptive multi-modal gesture recognition ABSTRACT: We present a method for gesture detection and localisation based on multi-scale and multi-modal deep learning. Each visual modality captures spatial information at a particular spatial scale (such as motion of the upper body or a hand), and the whole system operates at three temporal scales. Key to our technique is a training strategy which exploits: i) careful initialization of individual modalities; and ii) gradual fusion involving random dropping of separate channels (dubbed ModDrop) for learning cross-modality correlations while preserving uniqueness of each modality-specific representation. We present experiments on the ChaLearn 2014 Looking at People Challenge gesture recognition track, in which we placed first out of 17 teams. Fusing multiple modalities at several spatial and temporal scales leads to a significant increase in recognition rates, allowing the model to compensate for errors of the individual classifiers as well as noise in the separate channels. Futhermore, the proposed ModDrop training technique ensures robustness of the classifier to missing signals in one or several channels to produce meaningful predictions from any number of available modalities. In addition, we demonstrate the applicability of the proposed fusion scheme to modalities of arbitrary nature by experiments on the same dataset augmented with audio.
no_new_dataset
0.947088
1502.04754
Cosimo Rubino
Cosimo Rubino and Marco Crocco and Alessandro Perina and Vittorio Murino and Alessio Del Bue
3D Pose from Detections
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a novel method to infer, in closed-form, a general 3D spatial occupancy and orientation of a collection of rigid objects given 2D image detections from a sequence of images. In particular, starting from 2D ellipses fitted to bounding boxes, this novel multi-view problem can be reformulated as the estimation of a quadric (ellipsoid) in 3D. We show that an efficient solution exists in the dual-space using a minimum of three views while a solution with two views is possible through the use of regularization. However, this algebraic solution can be negatively affected in the presence of gross inaccuracies in the bounding boxes estimation. To this end, we also propose a robust ellipse fitting algorithm able to improve performance in the presence of errors in the detected objects. Results on synthetic tests and on different real datasets, involving real challenging scenarios, demonstrate the applicability and potential of our method.
[ { "version": "v1", "created": "Tue, 17 Feb 2015 00:11:41 GMT" }, { "version": "v2", "created": "Wed, 22 Apr 2015 23:40:57 GMT" }, { "version": "v3", "created": "Mon, 20 Jul 2015 18:27:38 GMT" } ]
2015-07-21T00:00:00
[ [ "Rubino", "Cosimo", "" ], [ "Crocco", "Marco", "" ], [ "Perina", "Alessandro", "" ], [ "Murino", "Vittorio", "" ], [ "Del Bue", "Alessio", "" ] ]
TITLE: 3D Pose from Detections ABSTRACT: We present a novel method to infer, in closed-form, a general 3D spatial occupancy and orientation of a collection of rigid objects given 2D image detections from a sequence of images. In particular, starting from 2D ellipses fitted to bounding boxes, this novel multi-view problem can be reformulated as the estimation of a quadric (ellipsoid) in 3D. We show that an efficient solution exists in the dual-space using a minimum of three views while a solution with two views is possible through the use of regularization. However, this algebraic solution can be negatively affected in the presence of gross inaccuracies in the bounding boxes estimation. To this end, we also propose a robust ellipse fitting algorithm able to improve performance in the presence of errors in the detected objects. Results on synthetic tests and on different real datasets, involving real challenging scenarios, demonstrate the applicability and potential of our method.
no_new_dataset
0.944638
1507.03148
Heng Yang
Heng Yang and Wenxuan Mou and Yichi Zhang and Ioannis Patras and Hatice Gunes and Peter Robinson
Face Alignment Assisted by Head Pose Estimation
Accepted by BMVC2015
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we propose a supervised initialization scheme for cascaded face alignment based on explicit head pose estimation. We first investigate the failure cases of most state of the art face alignment approaches and observe that these failures often share one common global property, i.e. the head pose variation is usually large. Inspired by this, we propose a deep convolutional network model for reliable and accurate head pose estimation. Instead of using a mean face shape, or randomly selected shapes for cascaded face alignment initialisation, we propose two schemes for generating initialisation: the first one relies on projecting a mean 3D face shape (represented by 3D facial landmarks) onto 2D image under the estimated head pose; the second one searches nearest neighbour shapes from the training set according to head pose distance. By doing so, the initialisation gets closer to the actual shape, which enhances the possibility of convergence and in turn improves the face alignment performance. We demonstrate the proposed method on the benchmark 300W dataset and show very competitive performance in both head pose estimation and face alignment.
[ { "version": "v1", "created": "Sat, 11 Jul 2015 20:07:51 GMT" }, { "version": "v2", "created": "Sat, 18 Jul 2015 12:36:58 GMT" } ]
2015-07-21T00:00:00
[ [ "Yang", "Heng", "" ], [ "Mou", "Wenxuan", "" ], [ "Zhang", "Yichi", "" ], [ "Patras", "Ioannis", "" ], [ "Gunes", "Hatice", "" ], [ "Robinson", "Peter", "" ] ]
TITLE: Face Alignment Assisted by Head Pose Estimation ABSTRACT: In this paper we propose a supervised initialization scheme for cascaded face alignment based on explicit head pose estimation. We first investigate the failure cases of most state of the art face alignment approaches and observe that these failures often share one common global property, i.e. the head pose variation is usually large. Inspired by this, we propose a deep convolutional network model for reliable and accurate head pose estimation. Instead of using a mean face shape, or randomly selected shapes for cascaded face alignment initialisation, we propose two schemes for generating initialisation: the first one relies on projecting a mean 3D face shape (represented by 3D facial landmarks) onto 2D image under the estimated head pose; the second one searches nearest neighbour shapes from the training set according to head pose distance. By doing so, the initialisation gets closer to the actual shape, which enhances the possibility of convergence and in turn improves the face alignment performance. We demonstrate the proposed method on the benchmark 300W dataset and show very competitive performance in both head pose estimation and face alignment.
no_new_dataset
0.950778
1507.05143
Paul Bendich
Christopher J. Tralie and Paul Bendich
Cover Song Identification with Timbral Shape Sequences
null
null
null
null
cs.SD
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We introduce a novel low level feature for identifying cover songs which quantifies the relative changes in the smoothed frequency spectrum of a song. Our key insight is that a sliding window representation of a chunk of audio can be viewed as a time-ordered point cloud in high dimensions. For corresponding chunks of audio between different versions of the same song, these point clouds are approximately rotated, translated, and scaled copies of each other. If we treat MFCC embeddings as point clouds and cast the problem as a relative shape sequence, we are able to correctly identify 42/80 cover songs in the "Covers 80" dataset. By contrast, all other work to date on cover songs exclusively relies on matching note sequences from Chroma derived features.
[ { "version": "v1", "created": "Sat, 18 Jul 2015 03:55:50 GMT" } ]
2015-07-21T00:00:00
[ [ "Tralie", "Christopher J.", "" ], [ "Bendich", "Paul", "" ] ]
TITLE: Cover Song Identification with Timbral Shape Sequences ABSTRACT: We introduce a novel low level feature for identifying cover songs which quantifies the relative changes in the smoothed frequency spectrum of a song. Our key insight is that a sliding window representation of a chunk of audio can be viewed as a time-ordered point cloud in high dimensions. For corresponding chunks of audio between different versions of the same song, these point clouds are approximately rotated, translated, and scaled copies of each other. If we treat MFCC embeddings as point clouds and cast the problem as a relative shape sequence, we are able to correctly identify 42/80 cover songs in the "Covers 80" dataset. By contrast, all other work to date on cover songs exclusively relies on matching note sequences from Chroma derived features.
no_new_dataset
0.946547
1507.05181
Matej Balog
Matej Balog and Yee Whye Teh
The Mondrian Process for Machine Learning
null
null
null
null
stat.ML cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This report is concerned with the Mondrian process and its applications in machine learning. The Mondrian process is a guillotine-partition-valued stochastic process that possesses an elegant self-consistency property. The first part of the report uses simple concepts from applied probability to define the Mondrian process and explore its properties. The Mondrian process has been used as the main building block of a clever online random forest classification algorithm that turns out to be equivalent to its batch counterpart. We outline a slight adaptation of this algorithm to regression, as the remainder of the report uses regression as a case study of how Mondrian processes can be utilized in machine learning. In particular, the Mondrian process will be used to construct a fast approximation to the computationally expensive kernel ridge regression problem with a Laplace kernel. The complexity of random guillotine partitions generated by a Mondrian process and hence the complexity of the resulting regression models is controlled by a lifetime hyperparameter. It turns out that these models can be efficiently trained and evaluated for all lifetimes in a given range at once, without needing to retrain them from scratch for each lifetime value. This leads to an efficient procedure for determining the right model complexity for a dataset at hand. The limitation of having a single lifetime hyperparameter will motivate the final Mondrian grid model, in which each input dimension is endowed with its own lifetime parameter. In this model we preserve the property that its hyperparameters can be tweaked without needing to retrain the modified model from scratch.
[ { "version": "v1", "created": "Sat, 18 Jul 2015 12:58:11 GMT" } ]
2015-07-21T00:00:00
[ [ "Balog", "Matej", "" ], [ "Teh", "Yee Whye", "" ] ]
TITLE: The Mondrian Process for Machine Learning ABSTRACT: This report is concerned with the Mondrian process and its applications in machine learning. The Mondrian process is a guillotine-partition-valued stochastic process that possesses an elegant self-consistency property. The first part of the report uses simple concepts from applied probability to define the Mondrian process and explore its properties. The Mondrian process has been used as the main building block of a clever online random forest classification algorithm that turns out to be equivalent to its batch counterpart. We outline a slight adaptation of this algorithm to regression, as the remainder of the report uses regression as a case study of how Mondrian processes can be utilized in machine learning. In particular, the Mondrian process will be used to construct a fast approximation to the computationally expensive kernel ridge regression problem with a Laplace kernel. The complexity of random guillotine partitions generated by a Mondrian process and hence the complexity of the resulting regression models is controlled by a lifetime hyperparameter. It turns out that these models can be efficiently trained and evaluated for all lifetimes in a given range at once, without needing to retrain them from scratch for each lifetime value. This leads to an efficient procedure for determining the right model complexity for a dataset at hand. The limitation of having a single lifetime hyperparameter will motivate the final Mondrian grid model, in which each input dimension is endowed with its own lifetime parameter. In this model we preserve the property that its hyperparameters can be tweaked without needing to retrain the modified model from scratch.
no_new_dataset
0.947235
1507.05245
Gautam Thakur
Gautam S. Thakur, Budhendra L. Bhaduri, Jesse O. Piburn, Kelly M. Sims, Robert N. Stewart, Marie L. Urban
PlanetSense: A Real-time Streaming and Spatio-temporal Analytics Platform for Gathering Geo-spatial Intelligence from Open Source Data
null
null
null
null
cs.CY cs.SI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Geospatial intelligence has traditionally relied on the use of archived and unvarying data for planning and exploration purposes. In consequence, the tools and methods that are architected to provide insight and generate projections only rely on such datasets. Albeit, if this approach has proven effective in several cases, such as land use identification and route mapping, it has severely restricted the ability of researchers to inculcate current information in their work. This approach is inadequate in scenarios requiring real-time information to act and to adjust in ever changing dynamic environments, such as evacuation and rescue missions. In this work, we propose PlanetSense, a platform for geospatial intelligence that is built to harness the existing power of archived data and add to that, the dynamics of real-time streams, seamlessly integrated with sophisticated data mining algorithms and analytics tools for generating operational intelligence on the fly. The platform has four main components - i. GeoData Cloud - a data architecture for storing and managing disparate datasets; ii. Mechanism to harvest real-time streaming data; iii. Data analytics framework; iv. Presentation and visualization through web interface and RESTful services. Using two case studies, we underpin the necessity of our platform in modeling ambient population and building occupancy at scale.
[ { "version": "v1", "created": "Sun, 19 Jul 2015 03:19:03 GMT" } ]
2015-07-21T00:00:00
[ [ "Thakur", "Gautam S.", "" ], [ "Bhaduri", "Budhendra L.", "" ], [ "Piburn", "Jesse O.", "" ], [ "Sims", "Kelly M.", "" ], [ "Stewart", "Robert N.", "" ], [ "Urban", "Marie L.", "" ] ]
TITLE: PlanetSense: A Real-time Streaming and Spatio-temporal Analytics Platform for Gathering Geo-spatial Intelligence from Open Source Data ABSTRACT: Geospatial intelligence has traditionally relied on the use of archived and unvarying data for planning and exploration purposes. In consequence, the tools and methods that are architected to provide insight and generate projections only rely on such datasets. Albeit, if this approach has proven effective in several cases, such as land use identification and route mapping, it has severely restricted the ability of researchers to inculcate current information in their work. This approach is inadequate in scenarios requiring real-time information to act and to adjust in ever changing dynamic environments, such as evacuation and rescue missions. In this work, we propose PlanetSense, a platform for geospatial intelligence that is built to harness the existing power of archived data and add to that, the dynamics of real-time streams, seamlessly integrated with sophisticated data mining algorithms and analytics tools for generating operational intelligence on the fly. The platform has four main components - i. GeoData Cloud - a data architecture for storing and managing disparate datasets; ii. Mechanism to harvest real-time streaming data; iii. Data analytics framework; iv. Presentation and visualization through web interface and RESTful services. Using two case studies, we underpin the necessity of our platform in modeling ambient population and building occupancy at scale.
no_new_dataset
0.948489
1507.05275
Swakkhar Shatabda
Shanjida Khatun, Hasib Ul Alam and Swakkhar Shatabda
An Efficient Genetic Algorithm for Discovering Diverse-Frequent Patterns
2015 International Conference on Electrical Engineering and Information Communication Technology (ICEEICT)
null
null
null
cs.AI
http://creativecommons.org/publicdomain/zero/1.0/
Working with exhaustive search on large dataset is infeasible for several reasons. Recently, developed techniques that made pattern set mining feasible by a general solver with long execution time that supports heuristic search and are limited to small datasets only. In this paper, we investigate an approach which aims to find diverse set of patterns using genetic algorithm to mine diverse frequent patterns. We propose a fast heuristic search algorithm that outperforms state-of-the-art methods on a standard set of benchmarks and capable to produce satisfactory results within a short period of time. Our proposed algorithm uses a relative encoding scheme for the patterns and an effective twin removal technique to ensure diversity throughout the search.
[ { "version": "v1", "created": "Sun, 19 Jul 2015 10:55:09 GMT" } ]
2015-07-21T00:00:00
[ [ "Khatun", "Shanjida", "" ], [ "Alam", "Hasib Ul", "" ], [ "Shatabda", "Swakkhar", "" ] ]
TITLE: An Efficient Genetic Algorithm for Discovering Diverse-Frequent Patterns ABSTRACT: Working with exhaustive search on large dataset is infeasible for several reasons. Recently, developed techniques that made pattern set mining feasible by a general solver with long execution time that supports heuristic search and are limited to small datasets only. In this paper, we investigate an approach which aims to find diverse set of patterns using genetic algorithm to mine diverse frequent patterns. We propose a fast heuristic search algorithm that outperforms state-of-the-art methods on a standard set of benchmarks and capable to produce satisfactory results within a short period of time. Our proposed algorithm uses a relative encoding scheme for the patterns and an effective twin removal technique to ensure diversity throughout the search.
no_new_dataset
0.951729
1507.05348
Zhaowei Cai
Zhaowei Cai, Mohammad Saberian, Nuno Vasconcelos
Learning Complexity-Aware Cascades for Deep Pedestrian Detection
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The design of complexity-aware cascaded detectors, combining features of very different complexities, is considered. A new cascade design procedure is introduced, by formulating cascade learning as the Lagrangian optimization of a risk that accounts for both accuracy and complexity. A boosting algorithm, denoted as complexity aware cascade training (CompACT), is then derived to solve this optimization. CompACT cascades are shown to seek an optimal trade-off between accuracy and complexity by pushing features of higher complexity to the later cascade stages, where only a few difficult candidate patches remain to be classified. This enables the use of features of vastly different complexities in a single detector. In result, the feature pool can be expanded to features previously impractical for cascade design, such as the responses of a deep convolutional neural network (CNN). This is demonstrated through the design of a pedestrian detector with a pool of features whose complexities span orders of magnitude. The resulting cascade generalizes the combination of a CNN with an object proposal mechanism: rather than a pre-processing stage, CompACT cascades seamlessly integrate CNNs in their stages. This enables state of the art performance on the Caltech and KITTI datasets, at fairly fast speeds.
[ { "version": "v1", "created": "Sun, 19 Jul 2015 22:31:01 GMT" } ]
2015-07-21T00:00:00
[ [ "Cai", "Zhaowei", "" ], [ "Saberian", "Mohammad", "" ], [ "Vasconcelos", "Nuno", "" ] ]
TITLE: Learning Complexity-Aware Cascades for Deep Pedestrian Detection ABSTRACT: The design of complexity-aware cascaded detectors, combining features of very different complexities, is considered. A new cascade design procedure is introduced, by formulating cascade learning as the Lagrangian optimization of a risk that accounts for both accuracy and complexity. A boosting algorithm, denoted as complexity aware cascade training (CompACT), is then derived to solve this optimization. CompACT cascades are shown to seek an optimal trade-off between accuracy and complexity by pushing features of higher complexity to the later cascade stages, where only a few difficult candidate patches remain to be classified. This enables the use of features of vastly different complexities in a single detector. In result, the feature pool can be expanded to features previously impractical for cascade design, such as the responses of a deep convolutional neural network (CNN). This is demonstrated through the design of a pedestrian detector with a pool of features whose complexities span orders of magnitude. The resulting cascade generalizes the combination of a CNN with an object proposal mechanism: rather than a pre-processing stage, CompACT cascades seamlessly integrate CNNs in their stages. This enables state of the art performance on the Caltech and KITTI datasets, at fairly fast speeds.
no_new_dataset
0.946646
1507.05408
Tobias Kuhn
Juan M. Banda and Tobias Kuhn and Nigam H. Shah and Michel Dumontier
Provenance-Centered Dataset of Drug-Drug Interactions
In Proceedings of the 14th International Semantic Web Conference (ISWC) 2015
null
null
null
cs.CY
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Over the years several studies have demonstrated the ability to identify potential drug-drug interactions via data mining from the literature (MEDLINE), electronic health records, public databases (Drugbank), etc. While each one of these approaches is properly statistically validated, they do not take into consideration the overlap between them as one of their decision making variables. In this paper we present LInked Drug-Drug Interactions (LIDDI), a public nanopublication-based RDF dataset with trusty URIs that encompasses some of the most cited prediction methods and sources to provide researchers a resource for leveraging the work of others into their prediction methods. As one of the main issues to overcome the usage of external resources is their mappings between drug names and identifiers used, we also provide the set of mappings we curated to be able to compare the multiple sources we aggregate in our dataset.
[ { "version": "v1", "created": "Mon, 20 Jul 2015 07:53:56 GMT" } ]
2015-07-21T00:00:00
[ [ "Banda", "Juan M.", "" ], [ "Kuhn", "Tobias", "" ], [ "Shah", "Nigam H.", "" ], [ "Dumontier", "Michel", "" ] ]
TITLE: Provenance-Centered Dataset of Drug-Drug Interactions ABSTRACT: Over the years several studies have demonstrated the ability to identify potential drug-drug interactions via data mining from the literature (MEDLINE), electronic health records, public databases (Drugbank), etc. While each one of these approaches is properly statistically validated, they do not take into consideration the overlap between them as one of their decision making variables. In this paper we present LInked Drug-Drug Interactions (LIDDI), a public nanopublication-based RDF dataset with trusty URIs that encompasses some of the most cited prediction methods and sources to provide researchers a resource for leveraging the work of others into their prediction methods. As one of the main issues to overcome the usage of external resources is their mappings between drug names and identifiers used, we also provide the set of mappings we curated to be able to compare the multiple sources we aggregate in our dataset.
new_dataset
0.960063
1507.05489
Andrea Romanoni
Andrea Romanoni, Matteo Matteucci
Efficient moving point handling for incremental 3D manifold reconstruction
Accepted in International Conference on Image Analysis and Processing (ICIAP 2015)
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
As incremental Structure from Motion algorithms become effective, a good sparse point cloud representing the map of the scene becomes available frame-by-frame. From the 3D Delaunay triangulation of these points, state-of-the-art algorithms build a manifold rough model of the scene. These algorithms integrate incrementally new points to the 3D reconstruction only if their position estimate does not change. Indeed, whenever a point moves in a 3D Delaunay triangulation, for instance because its estimation gets refined, a set of tetrahedra have to be removed and replaced with new ones to maintain the Delaunay property; the management of the manifold reconstruction becomes thus complex and it entails a potentially big overhead. In this paper we investigate different approaches and we propose an efficient policy to deal with moving points in the manifold estimation process. We tested our approach with four sequences of the KITTI dataset and we show the effectiveness of our proposal in comparison with state-of-the-art approaches.
[ { "version": "v1", "created": "Mon, 20 Jul 2015 13:38:02 GMT" } ]
2015-07-21T00:00:00
[ [ "Romanoni", "Andrea", "" ], [ "Matteucci", "Matteo", "" ] ]
TITLE: Efficient moving point handling for incremental 3D manifold reconstruction ABSTRACT: As incremental Structure from Motion algorithms become effective, a good sparse point cloud representing the map of the scene becomes available frame-by-frame. From the 3D Delaunay triangulation of these points, state-of-the-art algorithms build a manifold rough model of the scene. These algorithms integrate incrementally new points to the 3D reconstruction only if their position estimate does not change. Indeed, whenever a point moves in a 3D Delaunay triangulation, for instance because its estimation gets refined, a set of tetrahedra have to be removed and replaced with new ones to maintain the Delaunay property; the management of the manifold reconstruction becomes thus complex and it entails a potentially big overhead. In this paper we investigate different approaches and we propose an efficient policy to deal with moving points in the manifold estimation process. We tested our approach with four sequences of the KITTI dataset and we show the effectiveness of our proposal in comparison with state-of-the-art approaches.
no_new_dataset
0.949623
1507.05497
Dmitry Ignatov
Dmitry I. Ignatov and Denis Kornilov
RAPS: A Recommender Algorithm Based on Pattern Structures
The paper presented at FCA4AI 2015 in conjunction with IJCAI 2015
null
null
null
cs.IR cs.AI cs.DM
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a new algorithm for recommender systems with numeric ratings which is based on Pattern Structures (RAPS). As the input the algorithm takes rating matrix, e.g., such that it contains movies rated by users. For a target user, the algorithm returns a rated list of items (movies) based on its previous ratings and ratings of other users. We compare the results of the proposed algorithm in terms of precision and recall measures with Slope One, one of the state-of-the-art item-based algorithms, on Movie Lens dataset and RAPS demonstrates the best or comparable quality.
[ { "version": "v1", "created": "Mon, 20 Jul 2015 13:58:30 GMT" } ]
2015-07-21T00:00:00
[ [ "Ignatov", "Dmitry I.", "" ], [ "Kornilov", "Denis", "" ] ]
TITLE: RAPS: A Recommender Algorithm Based on Pattern Structures ABSTRACT: We propose a new algorithm for recommender systems with numeric ratings which is based on Pattern Structures (RAPS). As the input the algorithm takes rating matrix, e.g., such that it contains movies rated by users. For a target user, the algorithm returns a rated list of items (movies) based on its previous ratings and ratings of other users. We compare the results of the proposed algorithm in terms of precision and recall measures with Slope One, one of the state-of-the-art item-based algorithms, on Movie Lens dataset and RAPS demonstrates the best or comparable quality.
no_new_dataset
0.948965
1507.05578
Anant Raj
Anant Raj, Vinay P. Namboodiri and Tinne Tuytelaars
Subspace Alignment Based Domain Adaptation for RCNN Detector
26th British Machine Vision Conference, Swansea, UK
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we propose subspace alignment based domain adaptation of the state of the art RCNN based object detector. The aim is to be able to achieve high quality object detection in novel, real world target scenarios without requiring labels from the target domain. While, unsupervised domain adaptation has been studied in the case of object classification, for object detection it has been relatively unexplored. In subspace based domain adaptation for objects, we need access to source and target subspaces for the bounding box features. The absence of supervision (labels and bounding boxes are absent) makes the task challenging. In this paper, we show that we can still adapt sub- spaces that are localized to the object by obtaining detections from the RCNN detector trained on source and applied on target. Then we form localized subspaces from the detections and show that subspace alignment based adaptation between these subspaces yields improved object detection. This evaluation is done by considering challenging real world datasets of PASCAL VOC as source and validation set of Microsoft COCO dataset as target for various categories.
[ { "version": "v1", "created": "Mon, 20 Jul 2015 18:23:54 GMT" } ]
2015-07-21T00:00:00
[ [ "Raj", "Anant", "" ], [ "Namboodiri", "Vinay P.", "" ], [ "Tuytelaars", "Tinne", "" ] ]
TITLE: Subspace Alignment Based Domain Adaptation for RCNN Detector ABSTRACT: In this paper, we propose subspace alignment based domain adaptation of the state of the art RCNN based object detector. The aim is to be able to achieve high quality object detection in novel, real world target scenarios without requiring labels from the target domain. While, unsupervised domain adaptation has been studied in the case of object classification, for object detection it has been relatively unexplored. In subspace based domain adaptation for objects, we need access to source and target subspaces for the bounding box features. The absence of supervision (labels and bounding boxes are absent) makes the task challenging. In this paper, we show that we can still adapt sub- spaces that are localized to the object by obtaining detections from the RCNN detector trained on source and applied on target. Then we form localized subspaces from the detections and show that subspace alignment based adaptation between these subspaces yields improved object detection. This evaluation is done by considering challenging real world datasets of PASCAL VOC as source and validation set of Microsoft COCO dataset as target for various categories.
no_new_dataset
0.949856
1501.06814
Luca Rossi
Luca Rossi, James Walker, Mirco Musolesi
Spatio-Temporal Techniques for User Identification by means of GPS Mobility Data
11 pages, 8 figures
null
null
null
cs.CR cs.CY physics.data-an
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
One of the greatest concerns related to the popularity of GPS-enabled devices and applications is the increasing availability of the personal location information generated by them and shared with application and service providers. Moreover, people tend to have regular routines and be characterized by a set of "significant places", thus making it possible to identify a user from his/her mobility data. In this paper we present a series of techniques for identifying individuals from their GPS movements. More specifically, we study the uniqueness of GPS information for three popular datasets, and we provide a detailed analysis of the discriminatory power of speed, direction and distance of travel. Most importantly, we present a simple yet effective technique for the identification of users from location information that are not included in the original dataset used for training, thus raising important privacy concerns for the management of location datasets.
[ { "version": "v1", "created": "Tue, 27 Jan 2015 16:42:03 GMT" }, { "version": "v2", "created": "Sat, 31 Jan 2015 10:41:03 GMT" }, { "version": "v3", "created": "Fri, 17 Jul 2015 15:28:46 GMT" } ]
2015-07-20T00:00:00
[ [ "Rossi", "Luca", "" ], [ "Walker", "James", "" ], [ "Musolesi", "Mirco", "" ] ]
TITLE: Spatio-Temporal Techniques for User Identification by means of GPS Mobility Data ABSTRACT: One of the greatest concerns related to the popularity of GPS-enabled devices and applications is the increasing availability of the personal location information generated by them and shared with application and service providers. Moreover, people tend to have regular routines and be characterized by a set of "significant places", thus making it possible to identify a user from his/her mobility data. In this paper we present a series of techniques for identifying individuals from their GPS movements. More specifically, we study the uniqueness of GPS information for three popular datasets, and we provide a detailed analysis of the discriminatory power of speed, direction and distance of travel. Most importantly, we present a simple yet effective technique for the identification of users from location information that are not included in the original dataset used for training, thus raising important privacy concerns for the management of location datasets.
no_new_dataset
0.952175