id
stringlengths
9
16
submitter
stringlengths
3
64
authors
stringlengths
5
6.63k
title
stringlengths
7
245
comments
stringlengths
1
482
journal-ref
stringlengths
4
382
doi
stringlengths
9
151
report-no
stringclasses
984 values
categories
stringlengths
5
108
license
stringclasses
9 values
abstract
stringlengths
83
3.41k
versions
listlengths
1
20
update_date
timestamp[s]date
2007-05-23 00:00:00
2025-04-11 00:00:00
authors_parsed
sequencelengths
1
427
prompt
stringlengths
166
3.49k
label
stringclasses
2 values
prob
float64
0.5
0.98
1701.03940
Rafael Pinto
Rafael Pinto, Paulo Engel
Scalable and Incremental Learning of Gaussian Mixture Models
13 pages, 1 figure, submitted for peer-review. arXiv admin note: substantial text overlap with arXiv:1506.04422
null
null
null
cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This work presents a fast and scalable algorithm for incremental learning of Gaussian mixture models. By performing rank-one updates on its precision matrices and determinants, its asymptotic time complexity is of \BigO{NKD^2} for $N$ data points, $K$ Gaussian components and $D$ dimensions. The resulting algorithm can be applied to high dimensional tasks, and this is confirmed by applying it to the classification datasets MNIST and CIFAR-10. Additionally, in order to show the algorithm's applicability to function approximation and control tasks, it is applied to three reinforcement learning tasks and its data-efficiency is evaluated.
[ { "version": "v1", "created": "Sat, 14 Jan 2017 16:15:44 GMT" } ]
2017-01-17T00:00:00
[ [ "Pinto", "Rafael", "" ], [ "Engel", "Paulo", "" ] ]
TITLE: Scalable and Incremental Learning of Gaussian Mixture Models ABSTRACT: This work presents a fast and scalable algorithm for incremental learning of Gaussian mixture models. By performing rank-one updates on its precision matrices and determinants, its asymptotic time complexity is of \BigO{NKD^2} for $N$ data points, $K$ Gaussian components and $D$ dimensions. The resulting algorithm can be applied to high dimensional tasks, and this is confirmed by applying it to the classification datasets MNIST and CIFAR-10. Additionally, in order to show the algorithm's applicability to function approximation and control tasks, it is applied to three reinforcement learning tasks and its data-efficiency is evaluated.
no_new_dataset
0.947039
1701.04273
Hosein Azarbonyad
Hosein Azarbonyad and Mostafa Dehghani and Tom Kenter and Maarten Marx and Jaap Kamps and Maarten de Rijke
Hierarchical Re-estimation of Topic Models for Measuring Topical Diversity
Proceedings of the 39th European Conference on Information Retrieval (ECIR2017)
null
null
null
cs.IR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A high degree of topical diversity is often considered to be an important characteristic of interesting text documents. A recent proposal for measuring topical diversity identifies three elements for assessing diversity: words, topics, and documents as collections of words. Topic models play a central role in this approach. Using standard topic models for measuring diversity of documents is suboptimal due to generality and impurity. General topics only include common information from a background corpus and are assigned to most of the documents in the collection. Impure topics contain words that are not related to the topic; impurity lowers the interpretability of topic models and impure topics are likely to get assigned to documents erroneously. We propose a hierarchical re-estimation approach for topic models to combat generality and impurity; the proposed approach operates at three levels: words, topics, and documents. Our re-estimation approach for measuring documents' topical diversity outperforms the state of the art on PubMed dataset which is commonly used for diversity experiments.
[ { "version": "v1", "created": "Mon, 16 Jan 2017 12:59:47 GMT" } ]
2017-01-17T00:00:00
[ [ "Azarbonyad", "Hosein", "" ], [ "Dehghani", "Mostafa", "" ], [ "Kenter", "Tom", "" ], [ "Marx", "Maarten", "" ], [ "Kamps", "Jaap", "" ], [ "de Rijke", "Maarten", "" ] ]
TITLE: Hierarchical Re-estimation of Topic Models for Measuring Topical Diversity ABSTRACT: A high degree of topical diversity is often considered to be an important characteristic of interesting text documents. A recent proposal for measuring topical diversity identifies three elements for assessing diversity: words, topics, and documents as collections of words. Topic models play a central role in this approach. Using standard topic models for measuring diversity of documents is suboptimal due to generality and impurity. General topics only include common information from a background corpus and are assigned to most of the documents in the collection. Impure topics contain words that are not related to the topic; impurity lowers the interpretability of topic models and impure topics are likely to get assigned to documents erroneously. We propose a hierarchical re-estimation approach for topic models to combat generality and impurity; the proposed approach operates at three levels: words, topics, and documents. Our re-estimation approach for measuring documents' topical diversity outperforms the state of the art on PubMed dataset which is commonly used for diversity experiments.
no_new_dataset
0.954816
1701.04355
Hadrien Bertrand
Hadrien Bertrand, Matthieu Perrot, Roberto Ardon, Isabelle Bloch
Classification of MRI data using Deep Learning and Gaussian Process-based Model Selection
Accepted at ISBI 2017
null
null
null
cs.LG stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The classification of MRI images according to the anatomical field of view is a necessary task to solve when faced with the increasing quantity of medical images. In parallel, advances in deep learning makes it a suitable tool for computer vision problems. Using a common architecture (such as AlexNet) provides quite good results, but not sufficient for clinical use. Improving the model is not an easy task, due to the large number of hyper-parameters governing both the architecture and the training of the network, and to the limited understanding of their relevance. Since an exhaustive search is not tractable, we propose to optimize the network first by random search, and then by an adaptive search based on Gaussian Processes and Probability of Improvement. Applying this method on a large and varied MRI dataset, we show a substantial improvement between the baseline network and the final one (up to 20\% for the most difficult classes).
[ { "version": "v1", "created": "Mon, 16 Jan 2017 17:02:31 GMT" } ]
2017-01-17T00:00:00
[ [ "Bertrand", "Hadrien", "" ], [ "Perrot", "Matthieu", "" ], [ "Ardon", "Roberto", "" ], [ "Bloch", "Isabelle", "" ] ]
TITLE: Classification of MRI data using Deep Learning and Gaussian Process-based Model Selection ABSTRACT: The classification of MRI images according to the anatomical field of view is a necessary task to solve when faced with the increasing quantity of medical images. In parallel, advances in deep learning makes it a suitable tool for computer vision problems. Using a common architecture (such as AlexNet) provides quite good results, but not sufficient for clinical use. Improving the model is not an easy task, due to the large number of hyper-parameters governing both the architecture and the training of the network, and to the limited understanding of their relevance. Since an exhaustive search is not tractable, we propose to optimize the network first by random search, and then by an adaptive search based on Gaussian Processes and Probability of Improvement. Applying this method on a large and varied MRI dataset, we show a substantial improvement between the baseline network and the final one (up to 20\% for the most difficult classes).
no_new_dataset
0.94887
1609.03323
Julius Hannink
Julius Hannink, Thomas Kautz, Cristian F. Pasluosta, Karl-G\"unter Ga{\ss}mann, Jochen Klucken, Bjoern M. Eskofier
Sensor-based Gait Parameter Extraction with Deep Convolutional Neural Networks
in IEEE Journal of Biomedical and Health Informatics (2016)
null
10.1109/JBHI.2016.2636456
null
cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Measurement of stride-related, biomechanical parameters is the common rationale for objective gait impairment scoring. State-of-the-art double integration approaches to extract these parameters from inertial sensor data are, however, limited in their clinical applicability due to the underlying assumptions. To overcome this, we present a method to translate the abstract information provided by wearable sensors to context-related expert features based on deep convolutional neural networks. Regarding mobile gait analysis, this enables integration-free and data-driven extraction of a set of 8 spatio-temporal stride parameters. To this end, two modelling approaches are compared: A combined network estimating all parameters of interest and an ensemble approach that spawns less complex networks for each parameter individually. The ensemble approach is outperforming the combined modelling in the current application. On a clinically relevant and publicly available benchmark dataset, we estimate stride length, width and medio-lateral change in foot angle up to ${-0.15\pm6.09}$ cm, ${-0.09\pm4.22}$ cm and ${0.13 \pm 3.78^\circ}$ respectively. Stride, swing and stance time as well as heel and toe contact times are estimated up to ${\pm 0.07}$, ${\pm0.05}$, ${\pm 0.07}$, ${\pm0.07}$ and ${\pm0.12}$ s respectively. This is comparable to and in parts outperforming or defining state-of-the-art. Our results further indicate that the proposed change in methodology could substitute assumption-driven double-integration methods and enable mobile assessment of spatio-temporal stride parameters in clinically critical situations as e.g. in the case of spastic gait impairments.
[ { "version": "v1", "created": "Mon, 12 Sep 2016 09:33:57 GMT" }, { "version": "v2", "created": "Tue, 11 Oct 2016 10:56:32 GMT" }, { "version": "v3", "created": "Fri, 13 Jan 2017 12:30:39 GMT" } ]
2017-01-16T00:00:00
[ [ "Hannink", "Julius", "" ], [ "Kautz", "Thomas", "" ], [ "Pasluosta", "Cristian F.", "" ], [ "Gaßmann", "Karl-Günter", "" ], [ "Klucken", "Jochen", "" ], [ "Eskofier", "Bjoern M.", "" ] ]
TITLE: Sensor-based Gait Parameter Extraction with Deep Convolutional Neural Networks ABSTRACT: Measurement of stride-related, biomechanical parameters is the common rationale for objective gait impairment scoring. State-of-the-art double integration approaches to extract these parameters from inertial sensor data are, however, limited in their clinical applicability due to the underlying assumptions. To overcome this, we present a method to translate the abstract information provided by wearable sensors to context-related expert features based on deep convolutional neural networks. Regarding mobile gait analysis, this enables integration-free and data-driven extraction of a set of 8 spatio-temporal stride parameters. To this end, two modelling approaches are compared: A combined network estimating all parameters of interest and an ensemble approach that spawns less complex networks for each parameter individually. The ensemble approach is outperforming the combined modelling in the current application. On a clinically relevant and publicly available benchmark dataset, we estimate stride length, width and medio-lateral change in foot angle up to ${-0.15\pm6.09}$ cm, ${-0.09\pm4.22}$ cm and ${0.13 \pm 3.78^\circ}$ respectively. Stride, swing and stance time as well as heel and toe contact times are estimated up to ${\pm 0.07}$, ${\pm0.05}$, ${\pm 0.07}$, ${\pm0.07}$ and ${\pm0.12}$ s respectively. This is comparable to and in parts outperforming or defining state-of-the-art. Our results further indicate that the proposed change in methodology could substitute assumption-driven double-integration methods and enable mobile assessment of spatio-temporal stride parameters in clinically critical situations as e.g. in the case of spastic gait impairments.
no_new_dataset
0.9455
1701.03102
Xiang Xiang
Xiang Xiang, Trac D. Tran
Linear Disentangled Representation Learning for Facial Actions
Codes available at https://github.com/eglxiang/icassp15_emotion and https://github.com/eglxiang/FacialAU. arXiv admin note: text overlap with arXiv:1410.1606
null
null
null
cs.CV cs.AI cs.LG stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Limited annotated data available for the recognition of facial expression and action units embarrasses the training of deep networks, which can learn disentangled invariant features. However, a linear model with just several parameters normally is not demanding in terms of training data. In this paper, we propose an elegant linear model to untangle confounding factors in challenging realistic multichannel signals such as 2D face videos. The simple yet powerful model does not rely on huge training data and is natural for recognizing facial actions without explicitly disentangling the identity. Base on well-understood intuitive linear models such as Sparse Representation based Classification (SRC), previous attempts require a prepossessing of explicit decoupling which is practically inexact. Instead, we exploit the low-rank property across frames to subtract the underlying neutral faces which are modeled jointly with sparse representation on the action components with group sparsity enforced. On the extended Cohn-Kanade dataset (CK+), our one-shot automatic method on raw face videos performs as competitive as SRC applied on manually prepared action components and performs even better than SRC in terms of true positive rate. We apply the model to the even more challenging task of facial action unit recognition, verified on the MPI Face Video Database (MPI-VDB) achieving a decent performance. All the programs and data have been made publicly available.
[ { "version": "v1", "created": "Wed, 11 Jan 2017 16:34:29 GMT" } ]
2017-01-16T00:00:00
[ [ "Xiang", "Xiang", "" ], [ "Tran", "Trac D.", "" ] ]
TITLE: Linear Disentangled Representation Learning for Facial Actions ABSTRACT: Limited annotated data available for the recognition of facial expression and action units embarrasses the training of deep networks, which can learn disentangled invariant features. However, a linear model with just several parameters normally is not demanding in terms of training data. In this paper, we propose an elegant linear model to untangle confounding factors in challenging realistic multichannel signals such as 2D face videos. The simple yet powerful model does not rely on huge training data and is natural for recognizing facial actions without explicitly disentangling the identity. Base on well-understood intuitive linear models such as Sparse Representation based Classification (SRC), previous attempts require a prepossessing of explicit decoupling which is practically inexact. Instead, we exploit the low-rank property across frames to subtract the underlying neutral faces which are modeled jointly with sparse representation on the action components with group sparsity enforced. On the extended Cohn-Kanade dataset (CK+), our one-shot automatic method on raw face videos performs as competitive as SRC applied on manually prepared action components and performs even better than SRC in terms of true positive rate. We apply the model to the even more challenging task of facial action unit recognition, verified on the MPI Face Video Database (MPI-VDB) achieving a decent performance. All the programs and data have been made publicly available.
no_new_dataset
0.947088
1701.03551
Liang Lin
Keze Wang and Dongyu Zhang and Ya Li and Ruimao Zhang and Liang Lin
Cost-Effective Active Learning for Deep Image Classification
Accepted by IEEE Transactions on Circuits and Systems for Video Technology (TCSVT) 2016
null
10.1109/TCSVT.2016.2589879
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recent successes in learning-based image classification, however, heavily rely on the large number of annotated training samples, which may require considerable human efforts. In this paper, we propose a novel active learning framework, which is capable of building a competitive classifier with optimal feature representation via a limited amount of labeled training instances in an incremental learning manner. Our approach advances the existing active learning methods in two aspects. First, we incorporate deep convolutional neural networks into active learning. Through the properly designed framework, the feature representation and the classifier can be simultaneously updated with progressively annotated informative samples. Second, we present a cost-effective sample selection strategy to improve the classification performance with less manual annotations. Unlike traditional methods focusing on only the uncertain samples of low prediction confidence, we especially discover the large amount of high confidence samples from the unlabeled set for feature learning. Specifically, these high confidence samples are automatically selected and iteratively assigned pseudo-labels. We thus call our framework "Cost-Effective Active Learning" (CEAL) standing for the two advantages.Extensive experiments demonstrate that the proposed CEAL framework can achieve promising results on two challenging image classification datasets, i.e., face recognition on CACD database [1] and object categorization on Caltech-256 [2].
[ { "version": "v1", "created": "Fri, 13 Jan 2017 03:07:45 GMT" } ]
2017-01-16T00:00:00
[ [ "Wang", "Keze", "" ], [ "Zhang", "Dongyu", "" ], [ "Li", "Ya", "" ], [ "Zhang", "Ruimao", "" ], [ "Lin", "Liang", "" ] ]
TITLE: Cost-Effective Active Learning for Deep Image Classification ABSTRACT: Recent successes in learning-based image classification, however, heavily rely on the large number of annotated training samples, which may require considerable human efforts. In this paper, we propose a novel active learning framework, which is capable of building a competitive classifier with optimal feature representation via a limited amount of labeled training instances in an incremental learning manner. Our approach advances the existing active learning methods in two aspects. First, we incorporate deep convolutional neural networks into active learning. Through the properly designed framework, the feature representation and the classifier can be simultaneously updated with progressively annotated informative samples. Second, we present a cost-effective sample selection strategy to improve the classification performance with less manual annotations. Unlike traditional methods focusing on only the uncertain samples of low prediction confidence, we especially discover the large amount of high confidence samples from the unlabeled set for feature learning. Specifically, these high confidence samples are automatically selected and iteratively assigned pseudo-labels. We thus call our framework "Cost-Effective Active Learning" (CEAL) standing for the two advantages.Extensive experiments demonstrate that the proposed CEAL framework can achieve promising results on two challenging image classification datasets, i.e., face recognition on CACD database [1] and object categorization on Caltech-256 [2].
no_new_dataset
0.947914
1701.03682
Emrah Budur
Priyank Mathur, Arkajyoti Misra, Emrah Budur
LIDE: Language Identification from Text Documents
null
null
null
null
cs.CL cs.NE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The increase in the use of microblogging came along with the rapid growth on short linguistic data. On the other hand deep learning is considered to be the new frontier to extract meaningful information out of large amount of raw data in an automated manner. In this study, we engaged these two emerging fields to come up with a robust language identifier on demand, namely Language Identification Engine (LIDE). As a result, we achieved 95.12% accuracy in Discriminating between Similar Languages (DSL) Shared Task 2015 dataset, which is comparable to the maximum reported accuracy of 95.54% achieved so far.
[ { "version": "v1", "created": "Fri, 13 Jan 2017 14:20:06 GMT" } ]
2017-01-16T00:00:00
[ [ "Mathur", "Priyank", "" ], [ "Misra", "Arkajyoti", "" ], [ "Budur", "Emrah", "" ] ]
TITLE: LIDE: Language Identification from Text Documents ABSTRACT: The increase in the use of microblogging came along with the rapid growth on short linguistic data. On the other hand deep learning is considered to be the new frontier to extract meaningful information out of large amount of raw data in an automated manner. In this study, we engaged these two emerging fields to come up with a robust language identifier on demand, namely Language Identification Engine (LIDE). As a result, we achieved 95.12% accuracy in Discriminating between Similar Languages (DSL) Shared Task 2015 dataset, which is comparable to the maximum reported accuracy of 95.54% achieved so far.
no_new_dataset
0.939025
1607.07695
Itir Onal Ertugrul
Itir Onal Ertugrul, Mete Ozay, Fatos Tunay Yarman Vural
Hierarchical Multi-resolution Mesh Networks for Brain Decoding
18 pages
null
null
null
cs.NE cs.CV cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a new framework, called Hierarchical Multi-resolution Mesh Networks (HMMNs), which establishes a set of brain networks at multiple time resolutions of fMRI signal to represent the underlying cognitive process. The suggested framework, first, decomposes the fMRI signal into various frequency subbands using wavelet transforms. Then, a brain network, called mesh network, is formed at each subband by ensembling a set of local meshes. The locality around each anatomic region is defined with respect to a neighborhood system based on functional connectivity. The arc weights of a mesh are estimated by ridge regression formed among the average region time series. In the final step, the adjacency matrices of mesh networks obtained at different subbands are ensembled for brain decoding under a hierarchical learning architecture, called, fuzzy stacked generalization (FSG). Our results on Human Connectome Project task-fMRI dataset reflect that the suggested HMMN model can successfully discriminate tasks by extracting complementary information obtained from mesh arc weights of multiple subbands. We study the topological properties of the mesh networks at different resolutions using the network measures, namely, node degree, node strength, betweenness centrality and global efficiency; and investigate the connectivity of anatomic regions, during a cognitive task. We observe significant variations among the network topologies obtained for different subbands. We, also, analyze the diversity properties of classifier ensemble, trained by the mesh networks in multiple subbands and observe that the classifiers in the ensemble collaborate with each other to fuse the complementary information freed at each subband. We conclude that the fMRI data, recorded during a cognitive task, embed diverse information across the anatomic regions at each resolution.
[ { "version": "v1", "created": "Tue, 12 Jul 2016 17:26:31 GMT" }, { "version": "v2", "created": "Wed, 11 Jan 2017 20:42:47 GMT" } ]
2017-01-13T00:00:00
[ [ "Ertugrul", "Itir Onal", "" ], [ "Ozay", "Mete", "" ], [ "Vural", "Fatos Tunay Yarman", "" ] ]
TITLE: Hierarchical Multi-resolution Mesh Networks for Brain Decoding ABSTRACT: We propose a new framework, called Hierarchical Multi-resolution Mesh Networks (HMMNs), which establishes a set of brain networks at multiple time resolutions of fMRI signal to represent the underlying cognitive process. The suggested framework, first, decomposes the fMRI signal into various frequency subbands using wavelet transforms. Then, a brain network, called mesh network, is formed at each subband by ensembling a set of local meshes. The locality around each anatomic region is defined with respect to a neighborhood system based on functional connectivity. The arc weights of a mesh are estimated by ridge regression formed among the average region time series. In the final step, the adjacency matrices of mesh networks obtained at different subbands are ensembled for brain decoding under a hierarchical learning architecture, called, fuzzy stacked generalization (FSG). Our results on Human Connectome Project task-fMRI dataset reflect that the suggested HMMN model can successfully discriminate tasks by extracting complementary information obtained from mesh arc weights of multiple subbands. We study the topological properties of the mesh networks at different resolutions using the network measures, namely, node degree, node strength, betweenness centrality and global efficiency; and investigate the connectivity of anatomic regions, during a cognitive task. We observe significant variations among the network topologies obtained for different subbands. We, also, analyze the diversity properties of classifier ensemble, trained by the mesh networks in multiple subbands and observe that the classifiers in the ensemble collaborate with each other to fuse the complementary information freed at each subband. We conclude that the fMRI data, recorded during a cognitive task, embed diverse information across the anatomic regions at each resolution.
no_new_dataset
0.952794
1612.05476
Paul Swoboda
Paul Swoboda, Carsten Rother, Hassan Abu Alhaija, Dagmar Kainmueller, Bogdan Savchynskyy
A Study of Lagrangean Decompositions and Dual Ascent Solvers for Graph Matching
Added acknowledgments
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the quadratic assignment problem, in computer vision also known as graph matching. Two leading solvers for this problem optimize the Lagrange decomposition duals with sub-gradient and dual ascent (also known as message passing) updates. We explore s direction further and propose several additional Lagrangean relaxations of the graph matching problem along with corresponding algorithms, which are all based on a common dual ascent framework. Our extensive empirical evaluation gives several theoretical insights and suggests a new state-of-the-art any-time solver for the considered problem. Our improvement over state-of-the-art is particularly visible on a new dataset with large-scale sparse problem instances containing more than 500 graph nodes each.
[ { "version": "v1", "created": "Fri, 16 Dec 2016 14:14:42 GMT" }, { "version": "v2", "created": "Thu, 12 Jan 2017 11:51:00 GMT" } ]
2017-01-13T00:00:00
[ [ "Swoboda", "Paul", "" ], [ "Rother", "Carsten", "" ], [ "Alhaija", "Hassan Abu", "" ], [ "Kainmueller", "Dagmar", "" ], [ "Savchynskyy", "Bogdan", "" ] ]
TITLE: A Study of Lagrangean Decompositions and Dual Ascent Solvers for Graph Matching ABSTRACT: We study the quadratic assignment problem, in computer vision also known as graph matching. Two leading solvers for this problem optimize the Lagrange decomposition duals with sub-gradient and dual ascent (also known as message passing) updates. We explore s direction further and propose several additional Lagrangean relaxations of the graph matching problem along with corresponding algorithms, which are all based on a common dual ascent framework. Our extensive empirical evaluation gives several theoretical insights and suggests a new state-of-the-art any-time solver for the considered problem. Our improvement over state-of-the-art is particularly visible on a new dataset with large-scale sparse problem instances containing more than 500 graph nodes each.
new_dataset
0.954858
1701.02291
Tapabrata Ghosh
Tapabrata Ghosh
QuickNet: Maximizing Efficiency and Efficacy in Deep Architectures
Updated once
null
null
null
cs.LG stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present QuickNet, a fast and accurate network architecture that is both faster and significantly more accurate than other fast deep architectures like SqueezeNet. Furthermore, it uses less parameters than previous networks, making it more memory efficient. We do this by making two major modifications to the reference Darknet model (Redmon et al, 2015): 1) The use of depthwise separable convolutions and 2) The use of parametric rectified linear units. We make the observation that parametric rectified linear units are computationally equivalent to leaky rectified linear units at test time and the observation that separable convolutions can be interpreted as a compressed Inception network (Chollet, 2016). Using these observations, we derive a network architecture, which we call QuickNet, that is both faster and more accurate than previous models. Our architecture provides at least four major advantages: (1) A smaller model size, which is more tenable on memory constrained systems; (2) A significantly faster network which is more tenable on computationally constrained systems; (3) A high accuracy of 95.7 percent on the CIFAR-10 Dataset which outperforms all but one result published so far, although we note that our works are orthogonal approaches and can be combined (4) Orthogonality to previous model compression approaches allowing for further speed gains to be realized.
[ { "version": "v1", "created": "Mon, 9 Jan 2017 18:29:07 GMT" }, { "version": "v2", "created": "Thu, 12 Jan 2017 07:44:17 GMT" } ]
2017-01-13T00:00:00
[ [ "Ghosh", "Tapabrata", "" ] ]
TITLE: QuickNet: Maximizing Efficiency and Efficacy in Deep Architectures ABSTRACT: We present QuickNet, a fast and accurate network architecture that is both faster and significantly more accurate than other fast deep architectures like SqueezeNet. Furthermore, it uses less parameters than previous networks, making it more memory efficient. We do this by making two major modifications to the reference Darknet model (Redmon et al, 2015): 1) The use of depthwise separable convolutions and 2) The use of parametric rectified linear units. We make the observation that parametric rectified linear units are computationally equivalent to leaky rectified linear units at test time and the observation that separable convolutions can be interpreted as a compressed Inception network (Chollet, 2016). Using these observations, we derive a network architecture, which we call QuickNet, that is both faster and more accurate than previous models. Our architecture provides at least four major advantages: (1) A smaller model size, which is more tenable on memory constrained systems; (2) A significantly faster network which is more tenable on computationally constrained systems; (3) A high accuracy of 95.7 percent on the CIFAR-10 Dataset which outperforms all but one result published so far, although we note that our works are orthogonal approaches and can be combined (4) Orthogonality to previous model compression approaches allowing for further speed gains to be realized.
no_new_dataset
0.948917
1701.03129
Besat Kassaie
Besat Kassaie
De-identification In practice
null
null
null
null
cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We report our effort to identify the sensitive information, subset of data items listed by HIPAA (Health Insurance Portability and Accountability), from medical text using the recent advances in natural language processing and machine learning techniques. We represent the words with high dimensional continuous vectors learned by a variant of Word2Vec called Continous Bag Of Words (CBOW). We feed the word vectors into a simple neural network with a Long Short-Term Memory (LSTM) architecture. Without any attempts to extract manually crafted features and considering that our medical dataset is too small to be fed into neural network, we obtained promising results. The results thrilled us to think about the larger scale of the project with precise parameter tuning and other possible improvements.
[ { "version": "v1", "created": "Wed, 11 Jan 2017 19:22:56 GMT" } ]
2017-01-13T00:00:00
[ [ "Kassaie", "Besat", "" ] ]
TITLE: De-identification In practice ABSTRACT: We report our effort to identify the sensitive information, subset of data items listed by HIPAA (Health Insurance Portability and Accountability), from medical text using the recent advances in natural language processing and machine learning techniques. We represent the words with high dimensional continuous vectors learned by a variant of Word2Vec called Continous Bag Of Words (CBOW). We feed the word vectors into a simple neural network with a Long Short-Term Memory (LSTM) architecture. Without any attempts to extract manually crafted features and considering that our medical dataset is too small to be fed into neural network, we obtained promising results. The results thrilled us to think about the larger scale of the project with precise parameter tuning and other possible improvements.
no_new_dataset
0.947478
1701.03151
Mengtian Li
Mengtian Li and Daniel Huber
Guaranteed Parameter Estimation for Discrete Energy Minimization
WACV 2017: IEEE Winter Conference on Applications of Computer Vision
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Structural learning, a method to estimate the parameters for discrete energy minimization, has been proven to be effective in solving computer vision problems, especially in 3D scene parsing. As the complexity of the models increases, structural learning algorithms turn to approximate inference to retain tractability. Unfortunately, such methods often fail because the approximation can be arbitrarily poor. In this work, we propose a method to overcome this limitation through exploiting the properties of the joint problem of training time inference and learning. With the help of the learning framework, we transform the inapproximable inference problem into a polynomial time solvable one, thereby enabling tractable exact inference while still allowing an arbitrary graph structure and full potential interactions. Our learning algorithm is guaranteed to return a solution with a bounded error to the global optimal within the feasible parameter space. We demonstrate the effectiveness of this method on two point cloud scene parsing datasets. Our approach runs much faster and solves a problem that is intractable for previous, well-known approaches.
[ { "version": "v1", "created": "Wed, 11 Jan 2017 20:41:14 GMT" } ]
2017-01-13T00:00:00
[ [ "Li", "Mengtian", "" ], [ "Huber", "Daniel", "" ] ]
TITLE: Guaranteed Parameter Estimation for Discrete Energy Minimization ABSTRACT: Structural learning, a method to estimate the parameters for discrete energy minimization, has been proven to be effective in solving computer vision problems, especially in 3D scene parsing. As the complexity of the models increases, structural learning algorithms turn to approximate inference to retain tractability. Unfortunately, such methods often fail because the approximation can be arbitrarily poor. In this work, we propose a method to overcome this limitation through exploiting the properties of the joint problem of training time inference and learning. With the help of the learning framework, we transform the inapproximable inference problem into a polynomial time solvable one, thereby enabling tractable exact inference while still allowing an arbitrary graph structure and full potential interactions. Our learning algorithm is guaranteed to return a solution with a bounded error to the global optimal within the feasible parameter space. We demonstrate the effectiveness of this method on two point cloud scene parsing datasets. Our approach runs much faster and solves a problem that is intractable for previous, well-known approaches.
no_new_dataset
0.947284
1701.03281
Tao Wei
Tao Wei, Changhu Wang, Chang Wen Chen
Modularized Morphing of Neural Networks
12 pages, 6 figures, Under review as a conference paper at ICLR 2017
null
null
null
cs.LG cs.NE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work we study the problem of network morphism, an effective learning scheme to morph a well-trained neural network to a new one with the network function completely preserved. Different from existing work where basic morphing types on the layer level were addressed, we target at the central problem of network morphism at a higher level, i.e., how a convolutional layer can be morphed into an arbitrary module of a neural network. To simplify the representation of a network, we abstract a module as a graph with blobs as vertices and convolutional layers as edges, based on which the morphing process is able to be formulated as a graph transformation problem. Two atomic morphing operations are introduced to compose the graphs, based on which modules are classified into two families, i.e., simple morphable modules and complex modules. We present practical morphing solutions for both of these two families, and prove that any reasonable module can be morphed from a single convolutional layer. Extensive experiments have been conducted based on the state-of-the-art ResNet on benchmark datasets, and the effectiveness of the proposed solution has been verified.
[ { "version": "v1", "created": "Thu, 12 Jan 2017 09:48:53 GMT" } ]
2017-01-13T00:00:00
[ [ "Wei", "Tao", "" ], [ "Wang", "Changhu", "" ], [ "Chen", "Chang Wen", "" ] ]
TITLE: Modularized Morphing of Neural Networks ABSTRACT: In this work we study the problem of network morphism, an effective learning scheme to morph a well-trained neural network to a new one with the network function completely preserved. Different from existing work where basic morphing types on the layer level were addressed, we target at the central problem of network morphism at a higher level, i.e., how a convolutional layer can be morphed into an arbitrary module of a neural network. To simplify the representation of a network, we abstract a module as a graph with blobs as vertices and convolutional layers as edges, based on which the morphing process is able to be formulated as a graph transformation problem. Two atomic morphing operations are introduced to compose the graphs, based on which modules are classified into two families, i.e., simple morphable modules and complex modules. We present practical morphing solutions for both of these two families, and prove that any reasonable module can be morphed from a single convolutional layer. Extensive experiments have been conducted based on the state-of-the-art ResNet on benchmark datasets, and the effectiveness of the proposed solution has been verified.
no_new_dataset
0.946547
1701.03439
Ruotian Luo
Ruotian Luo, Gregory Shakhnarovich
Comprehension-guided referring expressions
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider generation and comprehension of natural language referring expression for objects in an image. Unlike generic "image captioning" which lacks natural standard evaluation criteria, quality of a referring expression may be measured by the receiver's ability to correctly infer which object is being described. Following this intuition, we propose two approaches to utilize models trained for comprehension task to generate better expressions. First, we use a comprehension module trained on human-generated expressions, as a "critic" of referring expression generator. The comprehension module serves as a differentiable proxy of human evaluation, providing training signal to the generation module. Second, we use the comprehension module in a generate-and-rerank pipeline, which chooses from candidate expressions generated by a model according to their performance on the comprehension task. We show that both approaches lead to improved referring expression generation on multiple benchmark datasets.
[ { "version": "v1", "created": "Thu, 12 Jan 2017 18:03:52 GMT" } ]
2017-01-13T00:00:00
[ [ "Luo", "Ruotian", "" ], [ "Shakhnarovich", "Gregory", "" ] ]
TITLE: Comprehension-guided referring expressions ABSTRACT: We consider generation and comprehension of natural language referring expression for objects in an image. Unlike generic "image captioning" which lacks natural standard evaluation criteria, quality of a referring expression may be measured by the receiver's ability to correctly infer which object is being described. Following this intuition, we propose two approaches to utilize models trained for comprehension task to generate better expressions. First, we use a comprehension module trained on human-generated expressions, as a "critic" of referring expression generator. The comprehension module serves as a differentiable proxy of human evaluation, providing training signal to the generation module. Second, we use the comprehension module in a generate-and-rerank pipeline, which chooses from candidate expressions generated by a model according to their performance on the comprehension task. We show that both approaches lead to improved referring expression generation on multiple benchmark datasets.
no_new_dataset
0.947039
1701.03441
Fathi Salem
Yuzhen Lu and Fathi M. Salem
Simplified Gating in Long Short-term Memory (LSTM) Recurrent Neural Networks
5 pages, 4 Figures, 3 Tables. arXiv admin note: substantial text overlap with arXiv:1612.03707
null
null
null
cs.NE stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The standard LSTM recurrent neural networks while very powerful in long-range dependency sequence applications have highly complex structure and relatively large (adaptive) parameters. In this work, we present empirical comparison between the standard LSTM recurrent neural network architecture and three new parameter-reduced variants obtained by eliminating combinations of the input signal, bias, and hidden unit signals from individual gating signals. The experiments on two sequence datasets show that the three new variants, called simply as LSTM1, LSTM2, and LSTM3, can achieve comparable performance to the standard LSTM model with less (adaptive) parameters.
[ { "version": "v1", "created": "Thu, 12 Jan 2017 18:12:05 GMT" } ]
2017-01-13T00:00:00
[ [ "Lu", "Yuzhen", "" ], [ "Salem", "Fathi M.", "" ] ]
TITLE: Simplified Gating in Long Short-term Memory (LSTM) Recurrent Neural Networks ABSTRACT: The standard LSTM recurrent neural networks while very powerful in long-range dependency sequence applications have highly complex structure and relatively large (adaptive) parameters. In this work, we present empirical comparison between the standard LSTM recurrent neural network architecture and three new parameter-reduced variants obtained by eliminating combinations of the input signal, bias, and hidden unit signals from individual gating signals. The experiments on two sequence datasets show that the three new variants, called simply as LSTM1, LSTM2, and LSTM3, can achieve comparable performance to the standard LSTM model with less (adaptive) parameters.
no_new_dataset
0.953144
1701.03452
Fathi Salem
Joel Heck and Fathi M. Salem
Simplified Minimal Gated Unit Variations for Recurrent Neural Networks
5 pages, 3 Figures, 5 Tables
null
null
null
cs.NE stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recurrent neural networks with various types of hidden units have been used to solve a diverse range of problems involving sequence data. Two of the most recent proposals, gated recurrent units (GRU) and minimal gated units (MGU), have shown comparable promising results on example public datasets. In this paper, we introduce three model variants of the minimal gated unit (MGU) which further simplify that design by reducing the number of parameters in the forget-gate dynamic equation. These three model variants, referred to simply as MGU1, MGU2, and MGU3, were tested on sequences generated from the MNIST dataset and from the Reuters Newswire Topics (RNT) dataset. The new models have shown similar accuracy to the MGU model while using fewer parameters and thus lowering training expense. One model variant, namely MGU2, performed better than MGU on the datasets considered, and thus may be used as an alternate to MGU or GRU in recurrent neural networks.
[ { "version": "v1", "created": "Thu, 12 Jan 2017 18:52:31 GMT" } ]
2017-01-13T00:00:00
[ [ "Heck", "Joel", "" ], [ "Salem", "Fathi M.", "" ] ]
TITLE: Simplified Minimal Gated Unit Variations for Recurrent Neural Networks ABSTRACT: Recurrent neural networks with various types of hidden units have been used to solve a diverse range of problems involving sequence data. Two of the most recent proposals, gated recurrent units (GRU) and minimal gated units (MGU), have shown comparable promising results on example public datasets. In this paper, we introduce three model variants of the minimal gated unit (MGU) which further simplify that design by reducing the number of parameters in the forget-gate dynamic equation. These three model variants, referred to simply as MGU1, MGU2, and MGU3, were tested on sequences generated from the MNIST dataset and from the Reuters Newswire Topics (RNT) dataset. The new models have shown similar accuracy to the MGU model while using fewer parameters and thus lowering training expense. One model variant, namely MGU2, performed better than MGU on the datasets considered, and thus may be used as an alternate to MGU or GRU in recurrent neural networks.
no_new_dataset
0.956594
1609.07197
Shyam Upadhyay
Shyam Upadhyay and Ming-Wei Chang
Annotating Derivations: A New Evaluation Strategy and Dataset for Algebra Word Problems
EACL 2017 long paper
null
null
null
cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a new evaluation for automatic solvers for algebra word problems, which can identify mistakes that existing evaluations overlook. Our proposal is to evaluate such solvers using derivations, which reflect how an equation system was constructed from the word problem. To accomplish this, we develop an algorithm for checking the equivalence between two derivations, and show how derivation an- notations can be semi-automatically added to existing datasets. To make our experiments more comprehensive, we include the derivation annotation for DRAW-1K, a new dataset containing 1000 general algebra word problems. In our experiments, we found that the annotated derivations enable a more accurate evaluation of automatic solvers than previously used metrics. We release derivation annotations for over 2300 algebra word problems for future evaluations.
[ { "version": "v1", "created": "Fri, 23 Sep 2016 00:38:59 GMT" }, { "version": "v2", "created": "Tue, 10 Jan 2017 20:05:38 GMT" } ]
2017-01-12T00:00:00
[ [ "Upadhyay", "Shyam", "" ], [ "Chang", "Ming-Wei", "" ] ]
TITLE: Annotating Derivations: A New Evaluation Strategy and Dataset for Algebra Word Problems ABSTRACT: We propose a new evaluation for automatic solvers for algebra word problems, which can identify mistakes that existing evaluations overlook. Our proposal is to evaluate such solvers using derivations, which reflect how an equation system was constructed from the word problem. To accomplish this, we develop an algorithm for checking the equivalence between two derivations, and show how derivation an- notations can be semi-automatically added to existing datasets. To make our experiments more comprehensive, we include the derivation annotation for DRAW-1K, a new dataset containing 1000 general algebra word problems. In our experiments, we found that the annotated derivations enable a more accurate evaluation of automatic solvers than previously used metrics. We release derivation annotations for over 2300 algebra word problems for future evaluations.
new_dataset
0.957991
1701.02829
Chenglong Li
Chenglong Li, Guizhao Wang, Yunpeng Ma, Aihua Zheng, Bin Luo, and Jin Tang
A Unified RGB-T Saliency Detection Benchmark: Dataset, Baselines, Analysis and A Novel Approach
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Despite significant progress, image saliency detection still remains a challenging task in complex scenes and environments. Integrating multiple different but complementary cues, like RGB and Thermal (RGB-T), may be an effective way for boosting saliency detection performance. The current research in this direction, however, is limited by the lack of a comprehensive benchmark. This work contributes such a RGB-T image dataset, which includes 821 spatially aligned RGB-T image pairs and their ground truth annotations for saliency detection purpose. The image pairs are with high diversity recorded under different scenes and environmental conditions, and we annotate 11 challenges on these image pairs for performing the challenge-sensitive analysis for different saliency detection algorithms. We also implement 3 kinds of baseline methods with different modality inputs to provide a comprehensive comparison platform. With this benchmark, we propose a novel approach, multi-task manifold ranking with cross-modality consistency, for RGB-T saliency detection. In particular, we introduce a weight for each modality to describe the reliability, and integrate them into the graph-based manifold ranking algorithm to achieve adaptive fusion of different source data. Moreover, we incorporate the cross-modality consistent constraints to integrate different modalities collaboratively. For the optimization, we design an efficient algorithm to iteratively solve several subproblems with closed-form solutions. Extensive experiments against other baseline methods on the newly created benchmark demonstrate the effectiveness of the proposed approach, and we also provide basic insights and potential future research directions for RGB-T saliency detection.
[ { "version": "v1", "created": "Wed, 11 Jan 2017 02:38:23 GMT" } ]
2017-01-12T00:00:00
[ [ "Li", "Chenglong", "" ], [ "Wang", "Guizhao", "" ], [ "Ma", "Yunpeng", "" ], [ "Zheng", "Aihua", "" ], [ "Luo", "Bin", "" ], [ "Tang", "Jin", "" ] ]
TITLE: A Unified RGB-T Saliency Detection Benchmark: Dataset, Baselines, Analysis and A Novel Approach ABSTRACT: Despite significant progress, image saliency detection still remains a challenging task in complex scenes and environments. Integrating multiple different but complementary cues, like RGB and Thermal (RGB-T), may be an effective way for boosting saliency detection performance. The current research in this direction, however, is limited by the lack of a comprehensive benchmark. This work contributes such a RGB-T image dataset, which includes 821 spatially aligned RGB-T image pairs and their ground truth annotations for saliency detection purpose. The image pairs are with high diversity recorded under different scenes and environmental conditions, and we annotate 11 challenges on these image pairs for performing the challenge-sensitive analysis for different saliency detection algorithms. We also implement 3 kinds of baseline methods with different modality inputs to provide a comprehensive comparison platform. With this benchmark, we propose a novel approach, multi-task manifold ranking with cross-modality consistency, for RGB-T saliency detection. In particular, we introduce a weight for each modality to describe the reliability, and integrate them into the graph-based manifold ranking algorithm to achieve adaptive fusion of different source data. Moreover, we incorporate the cross-modality consistent constraints to integrate different modalities collaboratively. For the optimization, we design an efficient algorithm to iteratively solve several subproblems with closed-form solutions. Extensive experiments against other baseline methods on the newly created benchmark demonstrate the effectiveness of the proposed approach, and we also provide basic insights and potential future research directions for RGB-T saliency detection.
new_dataset
0.967163
1701.02892
Xiaowei Zhang
Xiaowei Zhang and Chi Xu and Yu Zhang and Tingshao Zhu and Li Cheng
Multivariate Regression with Grossly Corrupted Observations: A Robust Approach and its Applications
null
null
null
null
stat.ML cs.CV cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper studies the problem of multivariate linear regression where a portion of the observations is grossly corrupted or is missing, and the magnitudes and locations of such occurrences are unknown in priori. To deal with this problem, we propose a new approach by explicitly consider the error source as well as its sparseness nature. An interesting property of our approach lies in its ability of allowing individual regression output elements or tasks to possess their unique noise levels. Moreover, despite working with a non-smooth optimization problem, our approach still guarantees to converge to its optimal solution. Experiments on synthetic data demonstrate the competitiveness of our approach compared with existing multivariate regression models. In addition, empirically our approach has been validated with very promising results on two exemplar real-world applications: The first concerns the prediction of \textit{Big-Five} personality based on user behaviors at social network sites (SNSs), while the second is 3D human hand pose estimation from depth images. The implementation of our approach and comparison methods as well as the involved datasets are made publicly available in support of the open-source and reproducible research initiatives.
[ { "version": "v1", "created": "Wed, 11 Jan 2017 08:52:53 GMT" } ]
2017-01-12T00:00:00
[ [ "Zhang", "Xiaowei", "" ], [ "Xu", "Chi", "" ], [ "Zhang", "Yu", "" ], [ "Zhu", "Tingshao", "" ], [ "Cheng", "Li", "" ] ]
TITLE: Multivariate Regression with Grossly Corrupted Observations: A Robust Approach and its Applications ABSTRACT: This paper studies the problem of multivariate linear regression where a portion of the observations is grossly corrupted or is missing, and the magnitudes and locations of such occurrences are unknown in priori. To deal with this problem, we propose a new approach by explicitly consider the error source as well as its sparseness nature. An interesting property of our approach lies in its ability of allowing individual regression output elements or tasks to possess their unique noise levels. Moreover, despite working with a non-smooth optimization problem, our approach still guarantees to converge to its optimal solution. Experiments on synthetic data demonstrate the competitiveness of our approach compared with existing multivariate regression models. In addition, empirically our approach has been validated with very promising results on two exemplar real-world applications: The first concerns the prediction of \textit{Big-Five} personality based on user behaviors at social network sites (SNSs), while the second is 3D human hand pose estimation from depth images. The implementation of our approach and comparison methods as well as the involved datasets are made publicly available in support of the open-source and reproducible research initiatives.
no_new_dataset
0.942823
1701.03041
Matthew Veres
Matthew Veres, Medhat Moussa, Graham W. Taylor
Modeling Grasp Motor Imagery through Deep Conditional Generative Models
Accepted for publication in Robotics and Automation Letters (RA-L)
null
null
null
cs.RO stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Grasping is a complex process involving knowledge of the object, the surroundings, and of oneself. While humans are able to integrate and process all of the sensory information required for performing this task, equipping machines with this capability is an extremely challenging endeavor. In this paper, we investigate how deep learning techniques can allow us to translate high-level concepts such as motor imagery to the problem of robotic grasp synthesis. We explore a paradigm based on generative models for learning integrated object-action representations, and demonstrate its capacity for capturing and generating multimodal, multi-finger grasp configurations on a simulated grasping dataset.
[ { "version": "v1", "created": "Wed, 11 Jan 2017 16:20:39 GMT" } ]
2017-01-12T00:00:00
[ [ "Veres", "Matthew", "" ], [ "Moussa", "Medhat", "" ], [ "Taylor", "Graham W.", "" ] ]
TITLE: Modeling Grasp Motor Imagery through Deep Conditional Generative Models ABSTRACT: Grasping is a complex process involving knowledge of the object, the surroundings, and of oneself. While humans are able to integrate and process all of the sensory information required for performing this task, equipping machines with this capability is an extremely challenging endeavor. In this paper, we investigate how deep learning techniques can allow us to translate high-level concepts such as motor imagery to the problem of robotic grasp synthesis. We explore a paradigm based on generative models for learning integrated object-action representations, and demonstrate its capacity for capturing and generating multimodal, multi-finger grasp configurations on a simulated grasping dataset.
no_new_dataset
0.945601
1701.03051
Venkata Naveen Reddy Chedeti
Tapan Sahni, Chinmay Chandak, Naveen Reddy Chedeti, Manish Singh
Efficient Twitter Sentiment Classification using Subjective Distant Supervision
null
null
null
null
cs.SI cs.CL cs.IR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
As microblogging services like Twitter are becoming more and more influential in today's globalised world, its facets like sentiment analysis are being extensively studied. We are no longer constrained by our own opinion. Others opinions and sentiments play a huge role in shaping our perspective. In this paper, we build on previous works on Twitter sentiment analysis using Distant Supervision. The existing approach requires huge computation resource for analysing large number of tweets. In this paper, we propose techniques to speed up the computation process for sentiment analysis. We use tweet subjectivity to select the right training samples. We also introduce the concept of EFWS (Effective Word Score) of a tweet that is derived from polarity scores of frequently used words, which is an additional heuristic that can be used to speed up the sentiment classification with standard machine learning algorithms. We performed our experiments using 1.6 million tweets. Experimental evaluations show that our proposed technique is more efficient and has higher accuracy compared to previously proposed methods. We achieve overall accuracies of around 80% (EFWS heuristic gives an accuracy around 85%) on a training dataset of 100K tweets, which is half the size of the dataset used for the baseline model. The accuracy of our proposed model is 2-3% higher than the baseline model, and the model effectively trains at twice the speed of the baseline model.
[ { "version": "v1", "created": "Wed, 11 Jan 2017 16:39:04 GMT" } ]
2017-01-12T00:00:00
[ [ "Sahni", "Tapan", "" ], [ "Chandak", "Chinmay", "" ], [ "Chedeti", "Naveen Reddy", "" ], [ "Singh", "Manish", "" ] ]
TITLE: Efficient Twitter Sentiment Classification using Subjective Distant Supervision ABSTRACT: As microblogging services like Twitter are becoming more and more influential in today's globalised world, its facets like sentiment analysis are being extensively studied. We are no longer constrained by our own opinion. Others opinions and sentiments play a huge role in shaping our perspective. In this paper, we build on previous works on Twitter sentiment analysis using Distant Supervision. The existing approach requires huge computation resource for analysing large number of tweets. In this paper, we propose techniques to speed up the computation process for sentiment analysis. We use tweet subjectivity to select the right training samples. We also introduce the concept of EFWS (Effective Word Score) of a tweet that is derived from polarity scores of frequently used words, which is an additional heuristic that can be used to speed up the sentiment classification with standard machine learning algorithms. We performed our experiments using 1.6 million tweets. Experimental evaluations show that our proposed technique is more efficient and has higher accuracy compared to previously proposed methods. We achieve overall accuracies of around 80% (EFWS heuristic gives an accuracy around 85%) on a training dataset of 100K tweets, which is half the size of the dataset used for the baseline model. The accuracy of our proposed model is 2-3% higher than the baseline model, and the model effectively trains at twice the speed of the baseline model.
no_new_dataset
0.948537
1701.03091
Besat Kassaie
Besat Kassaie
SPARQL over GraphX
null
null
null
null
cs.DB
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The ability of the RDF data model to link data from heterogeneous domains has led to an explosive growth of RDF data. So, evaluating SPARQL queries over large RDF data has been crucial for the semantic web community. However, due to the graph nature of RDF data, evaluating SPARQL queries in relational databases and common data-parallel systems needs a lot of joins and is inefficient. On the other hand, the enormity of datasets that are graph in nature such as social network data, has led the database community to develop graph-parallel processing systems to support iterative graph computations efficiently. In this work we take advantage of the graph representation of RDF data and exploit GraphX, a new graph processing system based on Spark. We propose a subgraph matching algorithm, compatible with the GraphX programming model to evaluate SPARQL queries. Some experiments are performed to show the system scalability to handle large datasets.
[ { "version": "v1", "created": "Wed, 11 Jan 2017 18:38:16 GMT" } ]
2017-01-12T00:00:00
[ [ "Kassaie", "Besat", "" ] ]
TITLE: SPARQL over GraphX ABSTRACT: The ability of the RDF data model to link data from heterogeneous domains has led to an explosive growth of RDF data. So, evaluating SPARQL queries over large RDF data has been crucial for the semantic web community. However, due to the graph nature of RDF data, evaluating SPARQL queries in relational databases and common data-parallel systems needs a lot of joins and is inefficient. On the other hand, the enormity of datasets that are graph in nature such as social network data, has led the database community to develop graph-parallel processing systems to support iterative graph computations efficiently. In this work we take advantage of the graph representation of RDF data and exploit GraphX, a new graph processing system based on Spark. We propose a subgraph matching algorithm, compatible with the GraphX programming model to evaluate SPARQL queries. Some experiments are performed to show the system scalability to handle large datasets.
no_new_dataset
0.943452
1503.06666
David Martins de Matos
Francisco Raposo, Ricardo Ribeiro, David Martins de Matos
Using Generic Summarization to Improve Music Information Retrieval Tasks
24 pages, 10 tables; Submitted to IEEE/ACM Transactions on Audio, Speech and Language Processing
IEEE/ACM Transactions on Audio, Speech and Language Processing, vol. 24, n. 6, March 2016
10.1109/TASLP.2016.2541299
null
cs.IR cs.LG cs.SD
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In order to satisfy processing time constraints, many MIR tasks process only a segment of the whole music signal. This practice may lead to decreasing performance, since the most important information for the tasks may not be in those processed segments. In this paper, we leverage generic summarization algorithms, previously applied to text and speech summarization, to summarize items in music datasets. These algorithms build summaries, that are both concise and diverse, by selecting appropriate segments from the input signal which makes them good candidates to summarize music as well. We evaluate the summarization process on binary and multiclass music genre classification tasks, by comparing the performance obtained using summarized datasets against the performances obtained using continuous segments (which is the traditional method used for addressing the previously mentioned time constraints) and full songs of the same original dataset. We show that GRASSHOPPER, LexRank, LSA, MMR, and a Support Sets-based Centrality model improve classification performance when compared to selected 30-second baselines. We also show that summarized datasets lead to a classification performance whose difference is not statistically significant from using full songs. Furthermore, we make an argument stating the advantages of sharing summarized datasets for future MIR research.
[ { "version": "v1", "created": "Mon, 23 Mar 2015 14:48:24 GMT" }, { "version": "v2", "created": "Thu, 3 Dec 2015 18:38:22 GMT" }, { "version": "v3", "created": "Wed, 9 Mar 2016 16:24:42 GMT" } ]
2017-01-11T00:00:00
[ [ "Raposo", "Francisco", "" ], [ "Ribeiro", "Ricardo", "" ], [ "de Matos", "David Martins", "" ] ]
TITLE: Using Generic Summarization to Improve Music Information Retrieval Tasks ABSTRACT: In order to satisfy processing time constraints, many MIR tasks process only a segment of the whole music signal. This practice may lead to decreasing performance, since the most important information for the tasks may not be in those processed segments. In this paper, we leverage generic summarization algorithms, previously applied to text and speech summarization, to summarize items in music datasets. These algorithms build summaries, that are both concise and diverse, by selecting appropriate segments from the input signal which makes them good candidates to summarize music as well. We evaluate the summarization process on binary and multiclass music genre classification tasks, by comparing the performance obtained using summarized datasets against the performances obtained using continuous segments (which is the traditional method used for addressing the previously mentioned time constraints) and full songs of the same original dataset. We show that GRASSHOPPER, LexRank, LSA, MMR, and a Support Sets-based Centrality model improve classification performance when compared to selected 30-second baselines. We also show that summarized datasets lead to a classification performance whose difference is not statistically significant from using full songs. Furthermore, we make an argument stating the advantages of sharing summarized datasets for future MIR research.
no_new_dataset
0.949106
1506.07401
Yang Wang
Yang Wang, Dong Zhou, Armin Bunde, and Shlomo Havlin
Testing reanalysis datasets in Antarctica: Trends, persistence properties and trend significance
8 pages, 5 figures
Journal of Geophysical Research: Atmosphere, 121 (21): 12839-12855, 2016
10.1002/2016JD024864
null
physics.ao-ph physics.soc-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The reanalysis datasets provide very important sources for investigating the climate dynamics and climate changes in Antarctica. In this paper, three major reanalysis data are compared with Antarctic station data over the last 35 years: the National Centers for Environmental Prediction and the National Center for Atmospheric Research reanalysis (NCEP1), NCEP-DOE Reanalysis 2 (NCEP2), and the European Centre for Medium-Range Weather Forecasts Interim Re-Analysis (ERA-Interim). In our assessment, we compare the linear trends, the fluctuations around the trends, the persistence properties and the significance level of warming trends in the reanalysis data with the observational ones. We find that NCEP1 and NCEP2 show spurious warming trends in all parts of Antarctica except the Peninsula, while ERA-Interim is quite reliable except at Amundsen-Scott. To investigate the persistence of the data sets, we consider the lag-1 autocorrelation $C(1)$ and the Hurst exponent. While $C(1)$ varies quite erratically in different stations, the Hurst exponent shows similar patterns all over Antarctica. Regarding the significance of the trends, NCEP1 and NCEP2 differ considerably from the observational datasets by strongly exaggerating the warming trends. In contrast, ERA-Interim gives reliable results at most stations except at Amundsen-Scott where it shows a significant cooling trend.
[ { "version": "v1", "created": "Wed, 24 Jun 2015 14:51:40 GMT" }, { "version": "v2", "created": "Tue, 10 Jan 2017 16:50:26 GMT" } ]
2017-01-11T00:00:00
[ [ "Wang", "Yang", "" ], [ "Zhou", "Dong", "" ], [ "Bunde", "Armin", "" ], [ "Havlin", "Shlomo", "" ] ]
TITLE: Testing reanalysis datasets in Antarctica: Trends, persistence properties and trend significance ABSTRACT: The reanalysis datasets provide very important sources for investigating the climate dynamics and climate changes in Antarctica. In this paper, three major reanalysis data are compared with Antarctic station data over the last 35 years: the National Centers for Environmental Prediction and the National Center for Atmospheric Research reanalysis (NCEP1), NCEP-DOE Reanalysis 2 (NCEP2), and the European Centre for Medium-Range Weather Forecasts Interim Re-Analysis (ERA-Interim). In our assessment, we compare the linear trends, the fluctuations around the trends, the persistence properties and the significance level of warming trends in the reanalysis data with the observational ones. We find that NCEP1 and NCEP2 show spurious warming trends in all parts of Antarctica except the Peninsula, while ERA-Interim is quite reliable except at Amundsen-Scott. To investigate the persistence of the data sets, we consider the lag-1 autocorrelation $C(1)$ and the Hurst exponent. While $C(1)$ varies quite erratically in different stations, the Hurst exponent shows similar patterns all over Antarctica. Regarding the significance of the trends, NCEP1 and NCEP2 differ considerably from the observational datasets by strongly exaggerating the warming trends. In contrast, ERA-Interim gives reliable results at most stations except at Amundsen-Scott where it shows a significant cooling trend.
no_new_dataset
0.946001
1602.08680
Shangwen Li
Shangwen Li, Sanjay Purushotham, Chen Chen, Yuzhuo Ren, and C.-C. Jay Kuo
Measuring and Predicting Tag Importance for Image Retrieval
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Textual data such as tags, sentence descriptions are combined with visual cues to reduce the semantic gap for image retrieval applications in today's Multimodal Image Retrieval (MIR) systems. However, all tags are treated as equally important in these systems, which may result in misalignment between visual and textual modalities during MIR training. This will further lead to degenerated retrieval performance at query time. To address this issue, we investigate the problem of tag importance prediction, where the goal is to automatically predict the tag importance and use it in image retrieval. To achieve this, we first propose a method to measure the relative importance of object and scene tags from image sentence descriptions. Using this as the ground truth, we present a tag importance prediction model to jointly exploit visual, semantic and context cues. The Structural Support Vector Machine (SSVM) formulation is adopted to ensure efficient training of the prediction model. Then, the Canonical Correlation Analysis (CCA) is employed to learn the relation between the image visual feature and tag importance to obtain robust retrieval performance. Experimental results on three real-world datasets show a significant performance improvement of the proposed MIR with Tag Importance Prediction (MIR/TIP) system over other MIR systems.
[ { "version": "v1", "created": "Sun, 28 Feb 2016 07:38:25 GMT" }, { "version": "v2", "created": "Thu, 14 Apr 2016 18:13:21 GMT" }, { "version": "v3", "created": "Mon, 9 Jan 2017 22:32:36 GMT" } ]
2017-01-11T00:00:00
[ [ "Li", "Shangwen", "" ], [ "Purushotham", "Sanjay", "" ], [ "Chen", "Chen", "" ], [ "Ren", "Yuzhuo", "" ], [ "Kuo", "C. -C. Jay", "" ] ]
TITLE: Measuring and Predicting Tag Importance for Image Retrieval ABSTRACT: Textual data such as tags, sentence descriptions are combined with visual cues to reduce the semantic gap for image retrieval applications in today's Multimodal Image Retrieval (MIR) systems. However, all tags are treated as equally important in these systems, which may result in misalignment between visual and textual modalities during MIR training. This will further lead to degenerated retrieval performance at query time. To address this issue, we investigate the problem of tag importance prediction, where the goal is to automatically predict the tag importance and use it in image retrieval. To achieve this, we first propose a method to measure the relative importance of object and scene tags from image sentence descriptions. Using this as the ground truth, we present a tag importance prediction model to jointly exploit visual, semantic and context cues. The Structural Support Vector Machine (SSVM) formulation is adopted to ensure efficient training of the prediction model. Then, the Canonical Correlation Analysis (CCA) is employed to learn the relation between the image visual feature and tag importance to obtain robust retrieval performance. Experimental results on three real-world datasets show a significant performance improvement of the proposed MIR with Tag Importance Prediction (MIR/TIP) system over other MIR systems.
no_new_dataset
0.948585
1609.09430
Shawn Hershey
Shawn Hershey, Sourish Chaudhuri, Daniel P. W. Ellis, Jort F. Gemmeke, Aren Jansen, R. Channing Moore, Manoj Plakal, Devin Platt, Rif A. Saurous, Bryan Seybold, Malcolm Slaney, Ron J. Weiss, Kevin Wilson
CNN Architectures for Large-Scale Audio Classification
Accepted for publication at ICASSP 2017 Changes: Added definitions of mAP, AUC, and d-prime. Updated mAP/AUC/d-prime numbers for Audio Set based on changes of latest Audio Set revision. Changed wording to fit 4 page limit with new additions
null
null
null
cs.SD cs.LG stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Convolutional Neural Networks (CNNs) have proven very effective in image classification and show promise for audio. We use various CNN architectures to classify the soundtracks of a dataset of 70M training videos (5.24 million hours) with 30,871 video-level labels. We examine fully connected Deep Neural Networks (DNNs), AlexNet [1], VGG [2], Inception [3], and ResNet [4]. We investigate varying the size of both training set and label vocabulary, finding that analogs of the CNNs used in image classification do well on our audio classification task, and larger training and label sets help up to a point. A model using embeddings from these classifiers does much better than raw features on the Audio Set [5] Acoustic Event Detection (AED) classification task.
[ { "version": "v1", "created": "Thu, 29 Sep 2016 17:04:50 GMT" }, { "version": "v2", "created": "Tue, 10 Jan 2017 18:06:51 GMT" } ]
2017-01-11T00:00:00
[ [ "Hershey", "Shawn", "" ], [ "Chaudhuri", "Sourish", "" ], [ "Ellis", "Daniel P. W.", "" ], [ "Gemmeke", "Jort F.", "" ], [ "Jansen", "Aren", "" ], [ "Moore", "R. Channing", "" ], [ "Plakal", "Manoj", "" ], [ "Platt", "Devin", "" ], [ "Saurous", "Rif A.", "" ], [ "Seybold", "Bryan", "" ], [ "Slaney", "Malcolm", "" ], [ "Weiss", "Ron J.", "" ], [ "Wilson", "Kevin", "" ] ]
TITLE: CNN Architectures for Large-Scale Audio Classification ABSTRACT: Convolutional Neural Networks (CNNs) have proven very effective in image classification and show promise for audio. We use various CNN architectures to classify the soundtracks of a dataset of 70M training videos (5.24 million hours) with 30,871 video-level labels. We examine fully connected Deep Neural Networks (DNNs), AlexNet [1], VGG [2], Inception [3], and ResNet [4]. We investigate varying the size of both training set and label vocabulary, finding that analogs of the CNNs used in image classification do well on our audio classification task, and larger training and label sets help up to a point. A model using embeddings from these classifiers does much better than raw features on the Audio Set [5] Acoustic Event Detection (AED) classification task.
no_new_dataset
0.939803
1612.06549
Heike Adel
Heike Adel and Hinrich Sch\"utze
Exploring Different Dimensions of Attention for Uncertainty Detection
accepted at EACL 2017
null
null
null
cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Neural networks with attention have proven effective for many natural language processing tasks. In this paper, we develop attention mechanisms for uncertainty detection. In particular, we generalize standardly used attention mechanisms by introducing external attention and sequence-preserving attention. These novel architectures differ from standard approaches in that they use external resources to compute attention weights and preserve sequence information. We compare them to other configurations along different dimensions of attention. Our novel architectures set the new state of the art on a Wikipedia benchmark dataset and perform similar to the state-of-the-art model on a biomedical benchmark which uses a large set of linguistic features.
[ { "version": "v1", "created": "Tue, 20 Dec 2016 08:49:59 GMT" }, { "version": "v2", "created": "Tue, 10 Jan 2017 14:56:03 GMT" } ]
2017-01-11T00:00:00
[ [ "Adel", "Heike", "" ], [ "Schütze", "Hinrich", "" ] ]
TITLE: Exploring Different Dimensions of Attention for Uncertainty Detection ABSTRACT: Neural networks with attention have proven effective for many natural language processing tasks. In this paper, we develop attention mechanisms for uncertainty detection. In particular, we generalize standardly used attention mechanisms by introducing external attention and sequence-preserving attention. These novel architectures differ from standard approaches in that they use external resources to compute attention weights and preserve sequence information. We compare them to other configurations along different dimensions of attention. Our novel architectures set the new state of the art on a Wikipedia benchmark dataset and perform similar to the state-of-the-art model on a biomedical benchmark which uses a large set of linguistic features.
no_new_dataset
0.953188
1612.06825
Le Hou
Veda Murthy, Le Hou, Dimitris Samaras, Tahsin M. Kurc, Joel H. Saltz
Center-Focusing Multi-task CNN with Injected Features for Classification of Glioma Nuclear Images
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Classifying the various shapes and attributes of a glioma cell nucleus is crucial for diagnosis and understanding the disease. We investigate automated classification of glioma nuclear shapes and visual attributes using Convolutional Neural Networks (CNNs) on pathology images of automatically segmented nuclei. We propose three methods that improve the performance of a previously-developed semi-supervised CNN. First, we propose a method that allows the CNN to focus on the most important part of an image- the image's center containing the nucleus. Second, we inject (concatenate) pre-extracted VGG features into an intermediate layer of our Semi-Supervised CNN so that during training, the CNN can learn a set of complementary features. Third, we separate the losses of the two groups of target classes (nuclear shapes and attributes) into a single-label loss and a multi-label loss so that the prior knowledge of inter-label exclusiveness can be incorporated. On a dataset of 2078 images, the proposed methods combined reduce the error rate of attribute and shape classification by 21.54% and 15.07% respectively compared to the existing state-of-the-art method on the same dataset.
[ { "version": "v1", "created": "Tue, 20 Dec 2016 19:54:37 GMT" }, { "version": "v2", "created": "Tue, 10 Jan 2017 18:44:32 GMT" } ]
2017-01-11T00:00:00
[ [ "Murthy", "Veda", "" ], [ "Hou", "Le", "" ], [ "Samaras", "Dimitris", "" ], [ "Kurc", "Tahsin M.", "" ], [ "Saltz", "Joel H.", "" ] ]
TITLE: Center-Focusing Multi-task CNN with Injected Features for Classification of Glioma Nuclear Images ABSTRACT: Classifying the various shapes and attributes of a glioma cell nucleus is crucial for diagnosis and understanding the disease. We investigate automated classification of glioma nuclear shapes and visual attributes using Convolutional Neural Networks (CNNs) on pathology images of automatically segmented nuclei. We propose three methods that improve the performance of a previously-developed semi-supervised CNN. First, we propose a method that allows the CNN to focus on the most important part of an image- the image's center containing the nucleus. Second, we inject (concatenate) pre-extracted VGG features into an intermediate layer of our Semi-Supervised CNN so that during training, the CNN can learn a set of complementary features. Third, we separate the losses of the two groups of target classes (nuclear shapes and attributes) into a single-label loss and a multi-label loss so that the prior knowledge of inter-label exclusiveness can be incorporated. On a dataset of 2078 images, the proposed methods combined reduce the error rate of attribute and shape classification by 21.54% and 15.07% respectively compared to the existing state-of-the-art method on the same dataset.
no_new_dataset
0.944125
1701.02485
Uzair Nadeem
Syed Afaq Ali Shah, Uzair Nadeem, Mohammed Bennamoun, Ferdous Sohel, Roberto Togneri
Efficient Image Set Classification using Linear Regression based Image Reconstruction
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a novel image set classification technique using linear regression models. Downsampled gallery image sets are interpreted as subspaces of a high dimensional space to avoid the computationally expensive training step. We estimate regression models for each test image using the class specific gallery subspaces. Images of the test set are then reconstructed using the regression models. Based on the minimum reconstruction error between the reconstructed and the original images, a weighted voting strategy is used to classify the test set. We performed extensive evaluation on the benchmark UCSD/Honda, CMU Mobo and YouTube Celebrity datasets for face classification, and ETH-80 dataset for object classification. The results demonstrate that by using only a small amount of training data, our technique achieved competitive classification accuracy and superior computational speed compared with the state-of-the-art methods.
[ { "version": "v1", "created": "Tue, 10 Jan 2017 09:17:29 GMT" } ]
2017-01-11T00:00:00
[ [ "Shah", "Syed Afaq Ali", "" ], [ "Nadeem", "Uzair", "" ], [ "Bennamoun", "Mohammed", "" ], [ "Sohel", "Ferdous", "" ], [ "Togneri", "Roberto", "" ] ]
TITLE: Efficient Image Set Classification using Linear Regression based Image Reconstruction ABSTRACT: We propose a novel image set classification technique using linear regression models. Downsampled gallery image sets are interpreted as subspaces of a high dimensional space to avoid the computationally expensive training step. We estimate regression models for each test image using the class specific gallery subspaces. Images of the test set are then reconstructed using the regression models. Based on the minimum reconstruction error between the reconstructed and the original images, a weighted voting strategy is used to classify the test set. We performed extensive evaluation on the benchmark UCSD/Honda, CMU Mobo and YouTube Celebrity datasets for face classification, and ETH-80 dataset for object classification. The results demonstrate that by using only a small amount of training data, our technique achieved competitive classification accuracy and superior computational speed compared with the state-of-the-art methods.
no_new_dataset
0.956513
1510.00012
Jianbo Ye
Jianbo Ye, Panruo Wu, James Z. Wang and Jia Li
Fast Discrete Distribution Clustering Using Wasserstein Barycenter with Sparse Support
double-column, 17 pages, 3 figures, 5 tables. English usage improved
null
null
null
stat.CO cs.LG stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In a variety of research areas, the weighted bag of vectors and the histogram are widely used descriptors for complex objects. Both can be expressed as discrete distributions. D2-clustering pursues the minimum total within-cluster variation for a set of discrete distributions subject to the Kantorovich-Wasserstein metric. D2-clustering has a severe scalability issue, the bottleneck being the computation of a centroid distribution, called Wasserstein barycenter, that minimizes its sum of squared distances to the cluster members. In this paper, we develop a modified Bregman ADMM approach for computing the approximate discrete Wasserstein barycenter of large clusters. In the case when the support points of the barycenters are unknown and have low cardinality, our method achieves high accuracy empirically at a much reduced computational cost. The strengths and weaknesses of our method and its alternatives are examined through experiments, and we recommend scenarios for their respective usage. Moreover, we develop both serial and parallelized versions of the algorithm. By experimenting with large-scale data, we demonstrate the computational efficiency of the new methods and investigate their convergence properties and numerical stability. The clustering results obtained on several datasets in different domains are highly competitive in comparison with some widely used methods in the corresponding areas.
[ { "version": "v1", "created": "Wed, 30 Sep 2015 20:10:59 GMT" }, { "version": "v2", "created": "Sun, 8 May 2016 22:40:26 GMT" }, { "version": "v3", "created": "Thu, 6 Oct 2016 23:41:22 GMT" }, { "version": "v4", "created": "Mon, 9 Jan 2017 18:14:20 GMT" } ]
2017-01-10T00:00:00
[ [ "Ye", "Jianbo", "" ], [ "Wu", "Panruo", "" ], [ "Wang", "James Z.", "" ], [ "Li", "Jia", "" ] ]
TITLE: Fast Discrete Distribution Clustering Using Wasserstein Barycenter with Sparse Support ABSTRACT: In a variety of research areas, the weighted bag of vectors and the histogram are widely used descriptors for complex objects. Both can be expressed as discrete distributions. D2-clustering pursues the minimum total within-cluster variation for a set of discrete distributions subject to the Kantorovich-Wasserstein metric. D2-clustering has a severe scalability issue, the bottleneck being the computation of a centroid distribution, called Wasserstein barycenter, that minimizes its sum of squared distances to the cluster members. In this paper, we develop a modified Bregman ADMM approach for computing the approximate discrete Wasserstein barycenter of large clusters. In the case when the support points of the barycenters are unknown and have low cardinality, our method achieves high accuracy empirically at a much reduced computational cost. The strengths and weaknesses of our method and its alternatives are examined through experiments, and we recommend scenarios for their respective usage. Moreover, we develop both serial and parallelized versions of the algorithm. By experimenting with large-scale data, we demonstrate the computational efficiency of the new methods and investigate their convergence properties and numerical stability. The clustering results obtained on several datasets in different domains are highly competitive in comparison with some widely used methods in the corresponding areas.
no_new_dataset
0.946547
1602.03966
Yongkun Li
Pengpeng Zhao, Yongkun Li, Hong Xie, Zhiyong Wu, Yinlong Xu, John C. S. Lui
Measuring and Maximizing Influence via Random Walk in Social Activity Networks
19 pages
null
null
null
cs.SI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
With the popularity of OSNs, finding a set of most influential users (or nodes) so as to trigger the largest influence cascade is of significance. For example, companies may take advantage of the "word-of-mouth" effect to trigger a large cascade of purchases by offering free samples/discounts to those most influential users. This task is usually modeled as an influence maximization problem, and it has been widely studied in the past decade. However, considering that users in OSNs may participate in various kinds of online activities, e.g., giving ratings to products, joining discussion groups, etc., influence diffusion through online activities becomes even more significant. In this paper, we study the impact of online activities by formulating the influence maximization problem for social-activity networks (SANs) containing both users and online activities. To address the computation challenge, we define an influence centrality via random walks to measure influence, then use the Monte Carlo framework to efficiently estimate the centrality in SANs. Furthermore, we develop a greedy-based algorithm with two novel optimization techniques to find the most influential users. By conducting extensive experiments with real-world datasets, we show our approach is more efficient than the state-of-the-art algorithm IMM[17] when we needs to handle large amount of online activities.
[ { "version": "v1", "created": "Fri, 12 Feb 2016 05:40:25 GMT" }, { "version": "v2", "created": "Mon, 9 Jan 2017 14:01:32 GMT" } ]
2017-01-10T00:00:00
[ [ "Zhao", "Pengpeng", "" ], [ "Li", "Yongkun", "" ], [ "Xie", "Hong", "" ], [ "Wu", "Zhiyong", "" ], [ "Xu", "Yinlong", "" ], [ "Lui", "John C. S.", "" ] ]
TITLE: Measuring and Maximizing Influence via Random Walk in Social Activity Networks ABSTRACT: With the popularity of OSNs, finding a set of most influential users (or nodes) so as to trigger the largest influence cascade is of significance. For example, companies may take advantage of the "word-of-mouth" effect to trigger a large cascade of purchases by offering free samples/discounts to those most influential users. This task is usually modeled as an influence maximization problem, and it has been widely studied in the past decade. However, considering that users in OSNs may participate in various kinds of online activities, e.g., giving ratings to products, joining discussion groups, etc., influence diffusion through online activities becomes even more significant. In this paper, we study the impact of online activities by formulating the influence maximization problem for social-activity networks (SANs) containing both users and online activities. To address the computation challenge, we define an influence centrality via random walks to measure influence, then use the Monte Carlo framework to efficiently estimate the centrality in SANs. Furthermore, we develop a greedy-based algorithm with two novel optimization techniques to find the most influential users. By conducting extensive experiments with real-world datasets, we show our approach is more efficient than the state-of-the-art algorithm IMM[17] when we needs to handle large amount of online activities.
no_new_dataset
0.947039
1603.02617
Rigas Kouskouridas
Caner Sahin, Rigas Kouskouridas and Tae-Kyun Kim
Iterative Hough Forest with Histogram of Control Points for 6 DoF Object Registration from Depth Images
IROS 2016
null
null
null
cs.CV cs.RO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
State-of-the-art techniques proposed for 6D object pose recovery depend on occlusion-free point clouds to accurately register objects in 3D space. To reduce this dependency, we introduce a novel architecture called Iterative Hough Forest with Histogram of Control Points that is capable of estimating occluded and cluttered objects' 6D pose given a candidate 2D bounding box. Our Iterative Hough Forest is learnt using patches extracted only from the positive samples. These patches are represented with Histogram of Control Points (HoCP), a "scale-variant" implicit volumetric description, which we derive from recently introduced Implicit B-Splines (IBS). The rich discriminative information provided by this scale-variance is leveraged during inference, where the initial pose estimation of the object is iteratively refined based on more discriminative control points by using our Iterative Hough Forest. We conduct experiments on several test objects of a publicly available dataset to test our architecture and to compare with the state-of-the-art.
[ { "version": "v1", "created": "Tue, 8 Mar 2016 18:33:44 GMT" }, { "version": "v2", "created": "Mon, 9 Jan 2017 12:43:53 GMT" } ]
2017-01-10T00:00:00
[ [ "Sahin", "Caner", "" ], [ "Kouskouridas", "Rigas", "" ], [ "Kim", "Tae-Kyun", "" ] ]
TITLE: Iterative Hough Forest with Histogram of Control Points for 6 DoF Object Registration from Depth Images ABSTRACT: State-of-the-art techniques proposed for 6D object pose recovery depend on occlusion-free point clouds to accurately register objects in 3D space. To reduce this dependency, we introduce a novel architecture called Iterative Hough Forest with Histogram of Control Points that is capable of estimating occluded and cluttered objects' 6D pose given a candidate 2D bounding box. Our Iterative Hough Forest is learnt using patches extracted only from the positive samples. These patches are represented with Histogram of Control Points (HoCP), a "scale-variant" implicit volumetric description, which we derive from recently introduced Implicit B-Splines (IBS). The rich discriminative information provided by this scale-variance is leveraged during inference, where the initial pose estimation of the object is iteratively refined based on more discriminative control points by using our Iterative Hough Forest. We conduct experiments on several test objects of a publicly available dataset to test our architecture and to compare with the state-of-the-art.
no_new_dataset
0.949576
1609.00680
Jinbo Xu
Sheng Wang, Siqi Sun, Zhen Li, Renyu Zhang and Jinbo Xu
Accurate De Novo Prediction of Protein Contact Map by Ultra-Deep Learning Model
null
PLoS Comput Biol 13(1): e1005324, 2017
10.1371/journal.pcbi.1005324
null
q-bio.BM cs.LG q-bio.QM stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recently exciting progress has been made on protein contact prediction, but the predicted contacts for proteins without many sequence homologs is still of low quality and not very useful for de novo structure prediction. This paper presents a new deep learning method that predicts contacts by integrating both evolutionary coupling (EC) and sequence conservation information through an ultra-deep neural network formed by two deep residual networks. This deep neural network allows us to model very complex sequence-contact relationship as well as long-range inter-contact correlation. Our method greatly outperforms existing contact prediction methods and leads to much more accurate contact-assisted protein folding. Tested on three datasets of 579 proteins, the average top L long-range prediction accuracy obtained our method, the representative EC method CCMpred and the CASP11 winner MetaPSICOV is 0.47, 0.21 and 0.30, respectively; the average top L/10 long-range accuracy of our method, CCMpred and MetaPSICOV is 0.77, 0.47 and 0.59, respectively. Ab initio folding using our predicted contacts as restraints can yield correct folds (i.e., TMscore>0.6) for 203 test proteins, while that using MetaPSICOV- and CCMpred-predicted contacts can do so for only 79 and 62 proteins, respectively. Further, our contact-assisted models have much better quality than template-based models. Using our predicted contacts as restraints, we can (ab initio) fold 208 of the 398 membrane proteins with TMscore>0.5. By contrast, when the training proteins of our method are used as templates, homology modeling can only do so for 10 of them. One interesting finding is that even if we do not train our prediction models with any membrane proteins, our method works very well on membrane protein prediction. Finally, in recent blind CAMEO benchmark our method successfully folded 5 test proteins with a novel fold.
[ { "version": "v1", "created": "Fri, 2 Sep 2016 17:41:54 GMT" }, { "version": "v2", "created": "Mon, 5 Sep 2016 15:39:23 GMT" }, { "version": "v3", "created": "Thu, 15 Sep 2016 03:09:45 GMT" }, { "version": "v4", "created": "Fri, 16 Sep 2016 23:08:52 GMT" }, { "version": "v5", "created": "Mon, 7 Nov 2016 06:01:32 GMT" }, { "version": "v6", "created": "Sun, 27 Nov 2016 22:32:50 GMT" } ]
2017-01-10T00:00:00
[ [ "Wang", "Sheng", "" ], [ "Sun", "Siqi", "" ], [ "Li", "Zhen", "" ], [ "Zhang", "Renyu", "" ], [ "Xu", "Jinbo", "" ] ]
TITLE: Accurate De Novo Prediction of Protein Contact Map by Ultra-Deep Learning Model ABSTRACT: Recently exciting progress has been made on protein contact prediction, but the predicted contacts for proteins without many sequence homologs is still of low quality and not very useful for de novo structure prediction. This paper presents a new deep learning method that predicts contacts by integrating both evolutionary coupling (EC) and sequence conservation information through an ultra-deep neural network formed by two deep residual networks. This deep neural network allows us to model very complex sequence-contact relationship as well as long-range inter-contact correlation. Our method greatly outperforms existing contact prediction methods and leads to much more accurate contact-assisted protein folding. Tested on three datasets of 579 proteins, the average top L long-range prediction accuracy obtained our method, the representative EC method CCMpred and the CASP11 winner MetaPSICOV is 0.47, 0.21 and 0.30, respectively; the average top L/10 long-range accuracy of our method, CCMpred and MetaPSICOV is 0.77, 0.47 and 0.59, respectively. Ab initio folding using our predicted contacts as restraints can yield correct folds (i.e., TMscore>0.6) for 203 test proteins, while that using MetaPSICOV- and CCMpred-predicted contacts can do so for only 79 and 62 proteins, respectively. Further, our contact-assisted models have much better quality than template-based models. Using our predicted contacts as restraints, we can (ab initio) fold 208 of the 398 membrane proteins with TMscore>0.5. By contrast, when the training proteins of our method are used as templates, homology modeling can only do so for 10 of them. One interesting finding is that even if we do not train our prediction models with any membrane proteins, our method works very well on membrane protein prediction. Finally, in recent blind CAMEO benchmark our method successfully folded 5 test proteins with a novel fold.
no_new_dataset
0.948585
1612.00775
Christopher Beckham
Christopher Beckham, Christopher Pal
A simple squared-error reformulation for ordinal classification
v1: Camera-ready abstract for NIPS for Health Workshop (2016) v2: Clean-up of some sections, added appendix section where we briefly explore optimisation of quadratic weighted kappa (QWK)
null
null
null
stat.ML cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we explore ordinal classification (in the context of deep neural networks) through a simple modification of the squared error loss which not only allows it to not only be sensitive to class ordering, but also allows the possibility of having a discrete probability distribution over the classes. Our formulation is based on the use of a softmax hidden layer, which has received relatively little attention in the literature. We empirically evaluate its performance on the Kaggle diabetic retinopathy dataset, an ordinal and high-resolution dataset and show that it outperforms all of the baselines employed.
[ { "version": "v1", "created": "Fri, 2 Dec 2016 17:57:04 GMT" }, { "version": "v2", "created": "Mon, 9 Jan 2017 16:04:38 GMT" } ]
2017-01-10T00:00:00
[ [ "Beckham", "Christopher", "" ], [ "Pal", "Christopher", "" ] ]
TITLE: A simple squared-error reformulation for ordinal classification ABSTRACT: In this paper, we explore ordinal classification (in the context of deep neural networks) through a simple modification of the squared error loss which not only allows it to not only be sensitive to class ordering, but also allows the possibility of having a discrete probability distribution over the classes. Our formulation is based on the use of a softmax hidden layer, which has received relatively little attention in the literature. We empirically evaluate its performance on the Kaggle diabetic retinopathy dataset, an ordinal and high-resolution dataset and show that it outperforms all of the baselines employed.
no_new_dataset
0.9462
1701.00495
Ariel Ephrat
Ariel Ephrat and Shmuel Peleg
Vid2speech: Speech Reconstruction from Silent Video
Accepted for publication at ICASSP 2017
null
null
null
cs.CV cs.SD
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Speechreading is a notoriously difficult task for humans to perform. In this paper we present an end-to-end model based on a convolutional neural network (CNN) for generating an intelligible acoustic speech signal from silent video frames of a speaking person. The proposed CNN generates sound features for each frame based on its neighboring frames. Waveforms are then synthesized from the learned speech features to produce intelligible speech. We show that by leveraging the automatic feature learning capabilities of a CNN, we can obtain state-of-the-art word intelligibility on the GRID dataset, and show promising results for learning out-of-vocabulary (OOV) words.
[ { "version": "v1", "created": "Mon, 2 Jan 2017 19:00:22 GMT" }, { "version": "v2", "created": "Mon, 9 Jan 2017 17:35:17 GMT" } ]
2017-01-10T00:00:00
[ [ "Ephrat", "Ariel", "" ], [ "Peleg", "Shmuel", "" ] ]
TITLE: Vid2speech: Speech Reconstruction from Silent Video ABSTRACT: Speechreading is a notoriously difficult task for humans to perform. In this paper we present an end-to-end model based on a convolutional neural network (CNN) for generating an intelligible acoustic speech signal from silent video frames of a speaking person. The proposed CNN generates sound features for each frame based on its neighboring frames. Waveforms are then synthesized from the learned speech features to produce intelligible speech. We show that by leveraging the automatic feature learning capabilities of a CNN, we can obtain state-of-the-art word intelligibility on the GRID dataset, and show promising results for learning out-of-vocabulary (OOV) words.
no_new_dataset
0.955569
1701.01811
Filippos Kokkinos
Filippos Kokkinos, Alexandros Potamianos
Structural Attention Neural Networks for improved sentiment analysis
Submitted to EACL2017 for review
null
null
null
cs.CL cs.NE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We introduce a tree-structured attention neural network for sentences and small phrases and apply it to the problem of sentiment classification. Our model expands the current recursive models by incorporating structural information around a node of a syntactic tree using both bottom-up and top-down information propagation. Also, the model utilizes structural attention to identify the most salient representations during the construction of the syntactic tree. To our knowledge, the proposed models achieve state of the art performance on the Stanford Sentiment Treebank dataset.
[ { "version": "v1", "created": "Sat, 7 Jan 2017 09:58:49 GMT" } ]
2017-01-10T00:00:00
[ [ "Kokkinos", "Filippos", "" ], [ "Potamianos", "Alexandros", "" ] ]
TITLE: Structural Attention Neural Networks for improved sentiment analysis ABSTRACT: We introduce a tree-structured attention neural network for sentences and small phrases and apply it to the problem of sentiment classification. Our model expands the current recursive models by incorporating structural information around a node of a syntactic tree using both bottom-up and top-down information propagation. Also, the model utilizes structural attention to identify the most salient representations during the construction of the syntactic tree. To our knowledge, the proposed models achieve state of the art performance on the Stanford Sentiment Treebank dataset.
no_new_dataset
0.949669
1701.01854
Mohaddeseh Bastan
Mohaddeseh Bastan, Shahram Khadivi, Mohammad Mehdi Homayounpour
Neural Machine Translation on Scarce-Resource Condition: A case-study on Persian-English
6 pages, Submitted in ICEE 2017
null
null
null
cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Neural Machine Translation (NMT) is a new approach for Machine Translation (MT), and due to its success, it has absorbed the attention of many researchers in the field. In this paper, we study NMT model on Persian-English language pairs, to analyze the model and investigate the appropriateness of the model for scarce-resourced scenarios, the situation that exists for Persian-centered translation systems. We adjust the model for the Persian language and find the best parameters and hyper parameters for two tasks: translation and transliteration. We also apply some preprocessing task on the Persian dataset which yields to increase for about one point in terms of BLEU score. Also, we have modified the loss function to enhance the word alignment of the model. This new loss function yields a total of 1.87 point improvements in terms of BLEU score in the translation quality.
[ { "version": "v1", "created": "Sat, 7 Jan 2017 16:27:44 GMT" } ]
2017-01-10T00:00:00
[ [ "Bastan", "Mohaddeseh", "" ], [ "Khadivi", "Shahram", "" ], [ "Homayounpour", "Mohammad Mehdi", "" ] ]
TITLE: Neural Machine Translation on Scarce-Resource Condition: A case-study on Persian-English ABSTRACT: Neural Machine Translation (NMT) is a new approach for Machine Translation (MT), and due to its success, it has absorbed the attention of many researchers in the field. In this paper, we study NMT model on Persian-English language pairs, to analyze the model and investigate the appropriateness of the model for scarce-resourced scenarios, the situation that exists for Persian-centered translation systems. We adjust the model for the Persian language and find the best parameters and hyper parameters for two tasks: translation and transliteration. We also apply some preprocessing task on the Persian dataset which yields to increase for about one point in terms of BLEU score. Also, we have modified the loss function to enhance the word alignment of the model. This new loss function yields a total of 1.87 point improvements in terms of BLEU score in the translation quality.
no_new_dataset
0.95222
1701.01875
Zeshan Hussain
Hardie Cate, Fahim Dalvi, and Zeshan Hussain
Sign Language Recognition Using Temporal Classification
5 pages
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Devices like the Myo armband available in the market today enable us to collect data about the position of a user's hands and fingers over time. We can use these technologies for sign language translation since each sign is roughly a combination of gestures across time. In this work, we utilize a dataset collected by a group at the University of South Wales, which contains parameters, such as hand position, hand rotation, and finger bend, for 95 unique signs. For each input stream representing a sign, we predict which sign class this stream falls into. We begin by implementing baseline SVM and logistic regression models, which perform reasonably well on high quality data. Lower quality data requires a more sophisticated approach, so we explore different methods in temporal classification, including long short term memory architectures and sequential pattern mining methods.
[ { "version": "v1", "created": "Sat, 7 Jan 2017 20:09:52 GMT" } ]
2017-01-10T00:00:00
[ [ "Cate", "Hardie", "" ], [ "Dalvi", "Fahim", "" ], [ "Hussain", "Zeshan", "" ] ]
TITLE: Sign Language Recognition Using Temporal Classification ABSTRACT: Devices like the Myo armband available in the market today enable us to collect data about the position of a user's hands and fingers over time. We can use these technologies for sign language translation since each sign is roughly a combination of gestures across time. In this work, we utilize a dataset collected by a group at the University of South Wales, which contains parameters, such as hand position, hand rotation, and finger bend, for 95 unique signs. For each input stream representing a sign, we predict which sign class this stream falls into. We begin by implementing baseline SVM and logistic regression models, which perform reasonably well on high quality data. Lower quality data requires a more sophisticated approach, so we explore different methods in temporal classification, including long short term memory architectures and sequential pattern mining methods.
no_new_dataset
0.942454
1701.01876
Zeshan Hussain
Hardie Cate, Fahim Dalvi, and Zeshan Hussain
DeepFace: Face Generation using Deep Learning
8 pages
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We use CNNs to build a system that both classifies images of faces based on a variety of different facial attributes and generates new faces given a set of desired facial characteristics. After introducing the problem and providing context in the first section, we discuss recent work related to image generation in Section 2. In Section 3, we describe the methods used to fine-tune our CNN and generate new images using a novel approach inspired by a Gaussian mixture model. In Section 4, we discuss our working dataset and describe our preprocessing steps and handling of facial attributes. Finally, in Sections 5, 6 and 7, we explain our experiments and results and conclude in the following section. Our classification system has 82\% test accuracy. Furthermore, our generation pipeline successfully creates well-formed faces.
[ { "version": "v1", "created": "Sat, 7 Jan 2017 20:22:05 GMT" } ]
2017-01-10T00:00:00
[ [ "Cate", "Hardie", "" ], [ "Dalvi", "Fahim", "" ], [ "Hussain", "Zeshan", "" ] ]
TITLE: DeepFace: Face Generation using Deep Learning ABSTRACT: We use CNNs to build a system that both classifies images of faces based on a variety of different facial attributes and generates new faces given a set of desired facial characteristics. After introducing the problem and providing context in the first section, we discuss recent work related to image generation in Section 2. In Section 3, we describe the methods used to fine-tune our CNN and generate new images using a novel approach inspired by a Gaussian mixture model. In Section 4, we discuss our working dataset and describe our preprocessing steps and handling of facial attributes. Finally, in Sections 5, 6 and 7, we explain our experiments and results and conclude in the following section. Our classification system has 82\% test accuracy. Furthermore, our generation pipeline successfully creates well-formed faces.
no_new_dataset
0.729279
1701.01908
Fan Xu
Fan Xu, Mingwen Wang and Maoxi Li
Sentence-level dialects identification in the greater China region
12
International Journal on Natural Language Computing (IJNLC) Vol. 5, No.6, December 2016
null
null
cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Identifying the different varieties of the same language is more challenging than unrelated languages identification. In this paper, we propose an approach to discriminate language varieties or dialects of Mandarin Chinese for the Mainland China, Hong Kong, Taiwan, Macao, Malaysia and Singapore, a.k.a., the Greater China Region (GCR). When applied to the dialects identification of the GCR, we find that the commonly used character-level or word-level uni-gram feature is not very efficient since there exist several specific problems such as the ambiguity and context-dependent characteristic of words in the dialects of the GCR. To overcome these challenges, we use not only the general features like character-level n-gram, but also many new word-level features, including PMI-based and word alignment-based features. A series of evaluation results on both the news and open-domain dataset from Wikipedia show the effectiveness of the proposed approach.
[ { "version": "v1", "created": "Sun, 8 Jan 2017 03:13:37 GMT" } ]
2017-01-10T00:00:00
[ [ "Xu", "Fan", "" ], [ "Wang", "Mingwen", "" ], [ "Li", "Maoxi", "" ] ]
TITLE: Sentence-level dialects identification in the greater China region ABSTRACT: Identifying the different varieties of the same language is more challenging than unrelated languages identification. In this paper, we propose an approach to discriminate language varieties or dialects of Mandarin Chinese for the Mainland China, Hong Kong, Taiwan, Macao, Malaysia and Singapore, a.k.a., the Greater China Region (GCR). When applied to the dialects identification of the GCR, we find that the commonly used character-level or word-level uni-gram feature is not very efficient since there exist several specific problems such as the ambiguity and context-dependent characteristic of words in the dialects of the GCR. To overcome these challenges, we use not only the general features like character-level n-gram, but also many new word-level features, including PMI-based and word alignment-based features. A series of evaluation results on both the news and open-domain dataset from Wikipedia show the effectiveness of the proposed approach.
no_new_dataset
0.955486
1701.01932
Andrea Baraldi
Andrea Baraldi, Michael Laurence Humber, Dirk Tiede and Stefan Lang
Stage 4 validation of the Satellite Image Automatic Mapper lightweight computer program for Earth observation Level 2 product generation, Part 2 Validation
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The European Space Agency (ESA) defines an Earth Observation (EO) Level 2 product as a multispectral (MS) image corrected for geometric, atmospheric, adjacency and topographic effects, stacked with its scene classification map (SCM) whose legend includes quality layers such as cloud and cloud-shadow. No ESA EO Level 2 product has ever been systematically generated at the ground segment. To contribute toward filling an information gap from EO big sensory data to the ESA EO Level 2 product, a Stage 4 validation (Val) of an off the shelf Satellite Image Automatic Mapper (SIAM) lightweight computer program for prior knowledge based MS color naming was conducted by independent means. A time-series of annual Web Enabled Landsat Data (WELD) image composites of the conterminous U.S. (CONUS) was selected as input dataset. The annual SIAM WELD maps of the CONUS were validated in comparison with the U.S. National Land Cover Data (NLCD) 2006 map. These test and reference maps share the same spatial resolution and spatial extent, but their map legends are not the same and must be harmonized. For the sake of readability this paper is split into two. The previous Part 1 Theory provided the multidisciplinary background of a priori color naming. The present Part 2 Validation presents and discusses Stage 4 Val results collected from the test SIAM WELD map time series and the reference NLCD map by an original protocol for wall to wall thematic map quality assessment without sampling, where the test and reference map legends can differ in agreement with the Part 1. Conclusions are that the SIAM-WELD maps instantiate a Level 2 SCM product whose legend is the FAO Land Cover Classification System (LCCS) taxonomy at the Dichotomous Phase (DP) Level 1 vegetation/nonvegetation, Level 2 terrestrial/aquatic or superior LCCS level.
[ { "version": "v1", "created": "Sun, 8 Jan 2017 09:35:30 GMT" } ]
2017-01-10T00:00:00
[ [ "Baraldi", "Andrea", "" ], [ "Humber", "Michael Laurence", "" ], [ "Tiede", "Dirk", "" ], [ "Lang", "Stefan", "" ] ]
TITLE: Stage 4 validation of the Satellite Image Automatic Mapper lightweight computer program for Earth observation Level 2 product generation, Part 2 Validation ABSTRACT: The European Space Agency (ESA) defines an Earth Observation (EO) Level 2 product as a multispectral (MS) image corrected for geometric, atmospheric, adjacency and topographic effects, stacked with its scene classification map (SCM) whose legend includes quality layers such as cloud and cloud-shadow. No ESA EO Level 2 product has ever been systematically generated at the ground segment. To contribute toward filling an information gap from EO big sensory data to the ESA EO Level 2 product, a Stage 4 validation (Val) of an off the shelf Satellite Image Automatic Mapper (SIAM) lightweight computer program for prior knowledge based MS color naming was conducted by independent means. A time-series of annual Web Enabled Landsat Data (WELD) image composites of the conterminous U.S. (CONUS) was selected as input dataset. The annual SIAM WELD maps of the CONUS were validated in comparison with the U.S. National Land Cover Data (NLCD) 2006 map. These test and reference maps share the same spatial resolution and spatial extent, but their map legends are not the same and must be harmonized. For the sake of readability this paper is split into two. The previous Part 1 Theory provided the multidisciplinary background of a priori color naming. The present Part 2 Validation presents and discusses Stage 4 Val results collected from the test SIAM WELD map time series and the reference NLCD map by an original protocol for wall to wall thematic map quality assessment without sampling, where the test and reference map legends can differ in agreement with the Part 1. Conclusions are that the SIAM-WELD maps instantiate a Level 2 SCM product whose legend is the FAO Land Cover Classification System (LCCS) taxonomy at the Dichotomous Phase (DP) Level 1 vegetation/nonvegetation, Level 2 terrestrial/aquatic or superior LCCS level.
no_new_dataset
0.960137
1701.02030
Timotheos Aslanidis
Timotheos Aslanidis and Stavros Birmpilis
An open shop approach in approximating optimal data transmission duration in WDM networks
9 pages, 5 figures, Second International Conference on Computer Science, Information Technology and Applications (CSITA 2016)
null
null
null
cs.NI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the past decade Optical WDM Networks (Wavelength Division Multiplexing) are being used quite often and especially as far as broadband applications are concerned. Message packets transmitted through such networks can be interrupted using time slots in order to maximize network usage and minimize the time required for all messages to reach their destination. However, preempting a packet will result in time cost. The problem of scheduling message packets through such a network is referred to as PBS and is known to be NP-Hard. In this paper we have reduced PBS to Open Shop Scheduling and designed variations of polynomially solvable instances of Open Shop to approximate PBS. We have combined these variations and called the induced algorithm HSA (Hybridic Scheduling Algorithm). We ran experiments to establish the efficiency of HSA and found that in all datasets used it produces schedules very close to the optimal. To further establish HSAs efficiency we ran tests to compare it to SGA, another algorithm which when tested in the past has yielded excellent results.
[ { "version": "v1", "created": "Sun, 8 Jan 2017 22:35:38 GMT" } ]
2017-01-10T00:00:00
[ [ "Aslanidis", "Timotheos", "" ], [ "Birmpilis", "Stavros", "" ] ]
TITLE: An open shop approach in approximating optimal data transmission duration in WDM networks ABSTRACT: In the past decade Optical WDM Networks (Wavelength Division Multiplexing) are being used quite often and especially as far as broadband applications are concerned. Message packets transmitted through such networks can be interrupted using time slots in order to maximize network usage and minimize the time required for all messages to reach their destination. However, preempting a packet will result in time cost. The problem of scheduling message packets through such a network is referred to as PBS and is known to be NP-Hard. In this paper we have reduced PBS to Open Shop Scheduling and designed variations of polynomially solvable instances of Open Shop to approximate PBS. We have combined these variations and called the induced algorithm HSA (Hybridic Scheduling Algorithm). We ran experiments to establish the efficiency of HSA and found that in all datasets used it produces schedules very close to the optimal. To further establish HSAs efficiency we ran tests to compare it to SGA, another algorithm which when tested in the past has yielded excellent results.
no_new_dataset
0.946399
1701.02166
Rigas Kouskouridas
Caner Sahin, Rigas Kouskouridas and Tae-Kyun Kim
A Learning-based Variable Size Part Extraction Architecture for 6D Object Pose Recovery in Depth
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
State-of-the-art techniques for 6D object pose recovery depend on occlusion-free point clouds to accurately register objects in 3D space. To deal with this shortcoming, we introduce a novel architecture called Iterative Hough Forest with Histogram of Control Points that is capable of estimating the 6D pose of occluded and cluttered objects given a candidate 2D bounding box. Our Iterative Hough Forest (IHF) is learnt using parts extracted only from the positive samples. These parts are represented with Histogram of Control Points (HoCP), a "scale-variant" implicit volumetric description, which we derive from recently introduced Implicit B-Splines (IBS). The rich discriminative information provided by the scale-variant HoCP features is leveraged during inference. An automatic variable size part extraction framework iteratively refines the object's initial pose that is roughly aligned due to the extraction of coarsest parts, the ones occupying the largest area in image pixels. The iterative refinement is accomplished based on finer (smaller) parts that are represented with more discriminative control point descriptors by using our Iterative Hough Forest. Experiments conducted on a publicly available dataset report that our approach show better registration performance than the state-of-the-art methods.
[ { "version": "v1", "created": "Mon, 9 Jan 2017 13:20:32 GMT" } ]
2017-01-10T00:00:00
[ [ "Sahin", "Caner", "" ], [ "Kouskouridas", "Rigas", "" ], [ "Kim", "Tae-Kyun", "" ] ]
TITLE: A Learning-based Variable Size Part Extraction Architecture for 6D Object Pose Recovery in Depth ABSTRACT: State-of-the-art techniques for 6D object pose recovery depend on occlusion-free point clouds to accurately register objects in 3D space. To deal with this shortcoming, we introduce a novel architecture called Iterative Hough Forest with Histogram of Control Points that is capable of estimating the 6D pose of occluded and cluttered objects given a candidate 2D bounding box. Our Iterative Hough Forest (IHF) is learnt using parts extracted only from the positive samples. These parts are represented with Histogram of Control Points (HoCP), a "scale-variant" implicit volumetric description, which we derive from recently introduced Implicit B-Splines (IBS). The rich discriminative information provided by the scale-variant HoCP features is leveraged during inference. An automatic variable size part extraction framework iteratively refines the object's initial pose that is roughly aligned due to the extraction of coarsest parts, the ones occupying the largest area in image pixels. The iterative refinement is accomplished based on finer (smaller) parts that are represented with more discriminative control point descriptors by using our Iterative Hough Forest. Experiments conducted on a publicly available dataset report that our approach show better registration performance than the state-of-the-art methods.
no_new_dataset
0.950503
1701.02243
Marco Gramaglia
Marco Gramaglia, Marco Fiore, Alberto Tarable, Albert Banchs
$k^{\tau,\epsilon}$-anonymity: Towards Privacy-Preserving Publishing of Spatiotemporal Trajectory Data
null
null
null
null
cs.CY cs.CR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Mobile network operators can track subscribers via passive or active monitoring of device locations. The recorded trajectories offer an unprecedented outlook on the activities of large user populations, which enables developing new networking solutions and services, and scaling up studies across research disciplines. Yet, the disclosure of individual trajectories raises significant privacy concerns: thus, these data are often protected by restrictive non-disclosure agreements that limit their availability and impede potential usages. In this paper, we contribute to the development of technical solutions to the problem of privacy-preserving publishing of spatiotemporal trajectories of mobile subscribers. We propose an algorithm that generalizes the data so that they satisfy $k^{\tau,\epsilon}$-anonymity, an original privacy criterion that thwarts attacks on trajectories. Evaluations with real-world datasets demonstrate that our algorithm attains its objective while retaining a substantial level of accuracy in the data. Our work is a step forward in the direction of open, privacy-preserving datasets of spatiotemporal trajectories.
[ { "version": "v1", "created": "Mon, 9 Jan 2017 16:24:32 GMT" } ]
2017-01-10T00:00:00
[ [ "Gramaglia", "Marco", "" ], [ "Fiore", "Marco", "" ], [ "Tarable", "Alberto", "" ], [ "Banchs", "Albert", "" ] ]
TITLE: $k^{\tau,\epsilon}$-anonymity: Towards Privacy-Preserving Publishing of Spatiotemporal Trajectory Data ABSTRACT: Mobile network operators can track subscribers via passive or active monitoring of device locations. The recorded trajectories offer an unprecedented outlook on the activities of large user populations, which enables developing new networking solutions and services, and scaling up studies across research disciplines. Yet, the disclosure of individual trajectories raises significant privacy concerns: thus, these data are often protected by restrictive non-disclosure agreements that limit their availability and impede potential usages. In this paper, we contribute to the development of technical solutions to the problem of privacy-preserving publishing of spatiotemporal trajectories of mobile subscribers. We propose an algorithm that generalizes the data so that they satisfy $k^{\tau,\epsilon}$-anonymity, an original privacy criterion that thwarts attacks on trajectories. Evaluations with real-world datasets demonstrate that our algorithm attains its objective while retaining a substantial level of accuracy in the data. Our work is a step forward in the direction of open, privacy-preserving datasets of spatiotemporal trajectories.
no_new_dataset
0.946646
1604.03901
Weifeng Chen
Weifeng Chen, Zhao Fu, Dawei Yang, Jia Deng
Single-Image Depth Perception in the Wild
null
null
null
null
cs.CV cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper studies single-image depth perception in the wild, i.e., recovering depth from a single image taken in unconstrained settings. We introduce a new dataset "Depth in the Wild" consisting of images in the wild annotated with relative depth between pairs of random points. We also propose a new algorithm that learns to estimate metric depth using annotations of relative depth. Compared to the state of the art, our algorithm is simpler and performs better. Experiments show that our algorithm, combined with existing RGB-D data and our new relative depth annotations, significantly improves single-image depth perception in the wild.
[ { "version": "v1", "created": "Wed, 13 Apr 2016 18:19:35 GMT" }, { "version": "v2", "created": "Fri, 6 Jan 2017 16:05:35 GMT" } ]
2017-01-09T00:00:00
[ [ "Chen", "Weifeng", "" ], [ "Fu", "Zhao", "" ], [ "Yang", "Dawei", "" ], [ "Deng", "Jia", "" ] ]
TITLE: Single-Image Depth Perception in the Wild ABSTRACT: This paper studies single-image depth perception in the wild, i.e., recovering depth from a single image taken in unconstrained settings. We introduce a new dataset "Depth in the Wild" consisting of images in the wild annotated with relative depth between pairs of random points. We also propose a new algorithm that learns to estimate metric depth using annotations of relative depth. Compared to the state of the art, our algorithm is simpler and performs better. Experiments show that our algorithm, combined with existing RGB-D data and our new relative depth annotations, significantly improves single-image depth perception in the wild.
new_dataset
0.960137
1609.05695
Mengnan Shi
Mengnan Shi, Fei Qin, Qixiang Ye, Zhenjun Han, Jianbin Jiao
A scalable convolutional neural network for task-specified scenarios via knowledge distillation
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we explore the redundancy in convolutional neural network, which scales with the complexity of vision tasks. Considering that many front-end visual systems are interested in only a limited range of visual targets, the removing of task-specified network redundancy can promote a wide range of potential applications. We propose a task-specified knowledge distillation algorithm to derive a simplified model with pre-set computation cost and minimized accuracy loss, which suits the resource constraint front-end systems well. Experiments on the MNIST and CIFAR10 datasets demonstrate the feasibility of the proposed approach as well as the existence of task-specified redundancy.
[ { "version": "v1", "created": "Mon, 19 Sep 2016 12:43:32 GMT" }, { "version": "v2", "created": "Fri, 6 Jan 2017 13:57:47 GMT" } ]
2017-01-09T00:00:00
[ [ "Shi", "Mengnan", "" ], [ "Qin", "Fei", "" ], [ "Ye", "Qixiang", "" ], [ "Han", "Zhenjun", "" ], [ "Jiao", "Jianbin", "" ] ]
TITLE: A scalable convolutional neural network for task-specified scenarios via knowledge distillation ABSTRACT: In this paper, we explore the redundancy in convolutional neural network, which scales with the complexity of vision tasks. Considering that many front-end visual systems are interested in only a limited range of visual targets, the removing of task-specified network redundancy can promote a wide range of potential applications. We propose a task-specified knowledge distillation algorithm to derive a simplified model with pre-set computation cost and minimized accuracy loss, which suits the resource constraint front-end systems well. Experiments on the MNIST and CIFAR10 datasets demonstrate the feasibility of the proposed approach as well as the existence of task-specified redundancy.
no_new_dataset
0.948394
1701.01480
Yi-Ling Chen
Yi-Ling Chen, Tzu-Wei Huang, Kai-Han Chang, Yu-Chen Tsai, Hwann-Tzong Chen, Bing-Yu Chen
Quantitative Analysis of Automatic Image Cropping Algorithms: A Dataset and Comparative Study
The dataset presented in this article can be found on <a href="https://github.com/yiling-chen/flickr-cropping-dataset">Github</a>
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Automatic photo cropping is an important tool for improving visual quality of digital photos without resorting to tedious manual selection. Traditionally, photo cropping is accomplished by determining the best proposal window through visual quality assessment or saliency detection. In essence, the performance of an image cropper highly depends on the ability to correctly rank a number of visually similar proposal windows. Despite the ranking nature of automatic photo cropping, little attention has been paid to learning-to-rank algorithms in tackling such a problem. In this work, we conduct an extensive study on traditional approaches as well as ranking-based croppers trained on various image features. In addition, a new dataset consisting of high quality cropping and pairwise ranking annotations is presented to evaluate the performance of various baselines. The experimental results on the new dataset provide useful insights into the design of better photo cropping algorithms.
[ { "version": "v1", "created": "Thu, 5 Jan 2017 21:22:22 GMT" } ]
2017-01-09T00:00:00
[ [ "Chen", "Yi-Ling", "" ], [ "Huang", "Tzu-Wei", "" ], [ "Chang", "Kai-Han", "" ], [ "Tsai", "Yu-Chen", "" ], [ "Chen", "Hwann-Tzong", "" ], [ "Chen", "Bing-Yu", "" ] ]
TITLE: Quantitative Analysis of Automatic Image Cropping Algorithms: A Dataset and Comparative Study ABSTRACT: Automatic photo cropping is an important tool for improving visual quality of digital photos without resorting to tedious manual selection. Traditionally, photo cropping is accomplished by determining the best proposal window through visual quality assessment or saliency detection. In essence, the performance of an image cropper highly depends on the ability to correctly rank a number of visually similar proposal windows. Despite the ranking nature of automatic photo cropping, little attention has been paid to learning-to-rank algorithms in tackling such a problem. In this work, we conduct an extensive study on traditional approaches as well as ranking-based croppers trained on various image features. In addition, a new dataset consisting of high quality cropping and pairwise ranking annotations is presented to evaluate the performance of various baselines. The experimental results on the new dataset provide useful insights into the design of better photo cropping algorithms.
new_dataset
0.959116
1701.01565
Edison Marrese-Taylor
Edison Marrese-Taylor, Yutaka Matsuo
Replication issues in syntax-based aspect extraction for opinion mining
Accepted in the EACL 2017 SRW
null
null
null
cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Reproducing experiments is an important instrument to validate previous work and build upon existing approaches. It has been tackled numerous times in different areas of science. In this paper, we introduce an empirical replicability study of three well-known algorithms for syntactic centric aspect-based opinion mining. We show that reproducing results continues to be a difficult endeavor, mainly due to the lack of details regarding preprocessing and parameter setting, as well as due to the absence of available implementations that clarify these details. We consider these are important threats to validity of the research on the field, specifically when compared to other problems in NLP where public datasets and code availability are critical validity components. We conclude by encouraging code-based research, which we think has a key role in helping researchers to understand the meaning of the state-of-the-art better and to generate continuous advances.
[ { "version": "v1", "created": "Fri, 6 Jan 2017 08:18:38 GMT" } ]
2017-01-09T00:00:00
[ [ "Marrese-Taylor", "Edison", "" ], [ "Matsuo", "Yutaka", "" ] ]
TITLE: Replication issues in syntax-based aspect extraction for opinion mining ABSTRACT: Reproducing experiments is an important instrument to validate previous work and build upon existing approaches. It has been tackled numerous times in different areas of science. In this paper, we introduce an empirical replicability study of three well-known algorithms for syntactic centric aspect-based opinion mining. We show that reproducing results continues to be a difficult endeavor, mainly due to the lack of details regarding preprocessing and parameter setting, as well as due to the absence of available implementations that clarify these details. We consider these are important threats to validity of the research on the field, specifically when compared to other problems in NLP where public datasets and code availability are critical validity components. We conclude by encouraging code-based research, which we think has a key role in helping researchers to understand the meaning of the state-of-the-art better and to generate continuous advances.
no_new_dataset
0.944842
1701.01692
Eshed Ohn-Bar
Eshed Ohn-Bar and Mohan M. Trivedi
To Boost or Not to Boost? On the Limits of Boosted Trees for Object Detection
ICPR, December 2016. Added WIDER FACE test results (Fig. 5)
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We aim to study the modeling limitations of the commonly employed boosted decision trees classifier. Inspired by the success of large, data-hungry visual recognition models (e.g. deep convolutional neural networks), this paper focuses on the relationship between modeling capacity of the weak learners, dataset size, and dataset properties. A set of novel experiments on the Caltech Pedestrian Detection benchmark results in the best known performance among non-CNN techniques while operating at fast run-time speed. Furthermore, the performance is on par with deep architectures (9.71% log-average miss rate), while using only HOG+LUV channels as features. The conclusions from this study are shown to generalize over different object detection domains as demonstrated on the FDDB face detection benchmark (93.37% accuracy). Despite the impressive performance, this study reveals the limited modeling capacity of the common boosted trees model, motivating a need for architectural changes in order to compete with multi-level and very deep architectures.
[ { "version": "v1", "created": "Fri, 6 Jan 2017 16:51:32 GMT" } ]
2017-01-09T00:00:00
[ [ "Ohn-Bar", "Eshed", "" ], [ "Trivedi", "Mohan M.", "" ] ]
TITLE: To Boost or Not to Boost? On the Limits of Boosted Trees for Object Detection ABSTRACT: We aim to study the modeling limitations of the commonly employed boosted decision trees classifier. Inspired by the success of large, data-hungry visual recognition models (e.g. deep convolutional neural networks), this paper focuses on the relationship between modeling capacity of the weak learners, dataset size, and dataset properties. A set of novel experiments on the Caltech Pedestrian Detection benchmark results in the best known performance among non-CNN techniques while operating at fast run-time speed. Furthermore, the performance is on par with deep architectures (9.71% log-average miss rate), while using only HOG+LUV channels as features. The conclusions from this study are shown to generalize over different object detection domains as demonstrated on the FDDB face detection benchmark (93.37% accuracy). Despite the impressive performance, this study reveals the limited modeling capacity of the common boosted trees model, motivating a need for architectural changes in order to compete with multi-level and very deep architectures.
no_new_dataset
0.946349
1504.07469
Ariel Ephrat
Yair Poleg, Ariel Ephrat, Shmuel Peleg, Chetan Arora
Compact CNN for Indexing Egocentric Videos
null
IEEE WACV'16, March 2016, pp. 1-9
10.1109/WACV.2016.7477708
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
While egocentric video is becoming increasingly popular, browsing it is very difficult. In this paper we present a compact 3D Convolutional Neural Network (CNN) architecture for long-term activity recognition in egocentric videos. Recognizing long-term activities enables us to temporally segment (index) long and unstructured egocentric videos. Existing methods for this task are based on hand tuned features derived from visible objects, location of hands, as well as optical flow. Given a sparse optical flow volume as input, our CNN classifies the camera wearer's activity. We obtain classification accuracy of 89%, which outperforms the current state-of-the-art by 19%. Additional evaluation is performed on an extended egocentric video dataset, classifying twice the amount of categories than current state-of-the-art. Furthermore, our CNN is able to recognize whether a video is egocentric or not with 99.2% accuracy, up by 24% from current state-of-the-art. To better understand what the network actually learns, we propose a novel visualization of CNN kernels as flow fields.
[ { "version": "v1", "created": "Tue, 28 Apr 2015 13:41:16 GMT" }, { "version": "v2", "created": "Tue, 24 Nov 2015 21:13:18 GMT" } ]
2017-01-06T00:00:00
[ [ "Poleg", "Yair", "" ], [ "Ephrat", "Ariel", "" ], [ "Peleg", "Shmuel", "" ], [ "Arora", "Chetan", "" ] ]
TITLE: Compact CNN for Indexing Egocentric Videos ABSTRACT: While egocentric video is becoming increasingly popular, browsing it is very difficult. In this paper we present a compact 3D Convolutional Neural Network (CNN) architecture for long-term activity recognition in egocentric videos. Recognizing long-term activities enables us to temporally segment (index) long and unstructured egocentric videos. Existing methods for this task are based on hand tuned features derived from visible objects, location of hands, as well as optical flow. Given a sparse optical flow volume as input, our CNN classifies the camera wearer's activity. We obtain classification accuracy of 89%, which outperforms the current state-of-the-art by 19%. Additional evaluation is performed on an extended egocentric video dataset, classifying twice the amount of categories than current state-of-the-art. Furthermore, our CNN is able to recognize whether a video is egocentric or not with 99.2% accuracy, up by 24% from current state-of-the-art. To better understand what the network actually learns, we propose a novel visualization of CNN kernels as flow fields.
no_new_dataset
0.950595
1604.02316
Willem Sanberg
Willem P. Sanberg, Gijs Dubbelman, Peter H.N. de With
Free-Space Detection with Self-Supervised and Online Trained Fully Convolutional Networks
version as accepted at IS&T Electronic Imaging - Autonomous Vehicles and Machines Conference (San Francisco USA, January 2017); updated with two additional robustness experiments and formatted in conference style; 8 pages, public data available
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recently, vision-based Advanced Driver Assist Systems have gained broad interest. In this work, we investigate free-space detection, for which we propose to employ a Fully Convolutional Network (FCN). We show that this FCN can be trained in a self-supervised manner and achieve similar results compared to training on manually annotated data, thereby reducing the need for large manually annotated training sets. To this end, our self-supervised training relies on a stereo-vision disparity system, to automatically generate (weak) training labels for the color-based FCN. Additionally, our self-supervised training facilitates online training of the FCN instead of offline. Consequently, given that the applied FCN is relatively small, the free-space analysis becomes highly adaptive to any traffic scene that the vehicle encounters. We have validated our algorithm using publicly available data and on a new challenging benchmark dataset that is released with this paper. Experiments show that the online training boosts performance with 5% when compared to offline training, both for Fmax and AP.
[ { "version": "v1", "created": "Fri, 8 Apr 2016 11:54:40 GMT" }, { "version": "v2", "created": "Thu, 5 Jan 2017 13:59:30 GMT" } ]
2017-01-06T00:00:00
[ [ "Sanberg", "Willem P.", "" ], [ "Dubbelman", "Gijs", "" ], [ "de With", "Peter H. N.", "" ] ]
TITLE: Free-Space Detection with Self-Supervised and Online Trained Fully Convolutional Networks ABSTRACT: Recently, vision-based Advanced Driver Assist Systems have gained broad interest. In this work, we investigate free-space detection, for which we propose to employ a Fully Convolutional Network (FCN). We show that this FCN can be trained in a self-supervised manner and achieve similar results compared to training on manually annotated data, thereby reducing the need for large manually annotated training sets. To this end, our self-supervised training relies on a stereo-vision disparity system, to automatically generate (weak) training labels for the color-based FCN. Additionally, our self-supervised training facilitates online training of the FCN instead of offline. Consequently, given that the applied FCN is relatively small, the free-space analysis becomes highly adaptive to any traffic scene that the vehicle encounters. We have validated our algorithm using publicly available data and on a new challenging benchmark dataset that is released with this paper. Experiments show that the online training boosts performance with 5% when compared to offline training, both for Fmax and AP.
new_dataset
0.960731
1610.05653
Luca Remaggi
Luca Remaggi and Philip J. B. Jackson and Philip Coleman and Wenwu Wang
Acoustic Reflector Localization: Novel Image Source Reversion and Direct Localization Methods
null
IEEE/ACM Transactions on Audio, Speech, and Language Processing, vol. 25, no. 2, pp. 296-309, February 2017
10.1109/TASLP.2016.2633802
null
cs.SD
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Acoustic reflector localization is an important issue in audio signal processing, with direct applications in spatial audio, scene reconstruction, and source separation. Several methods have recently been proposed to estimate the 3D positions of acoustic reflectors given room impulse responses (RIRs). In this article, we categorize these methods as "image-source reversion", which localizes the image source before finding the reflector position, and "direct localization", which localizes the reflector without intermediate steps. We present five new contributions. First, an onset detector, called the clustered dynamic programming projected phase-slope algorithm, is proposed to automatically extract the time of arrival for early reflections within the RIRs of a compact microphone array. Second, we propose an image-source reversion method that uses the RIRs from a single loudspeaker. It is constructed by combining an image source locator (the image source direction and range (ISDAR) algorithm), and a reflector locator (using the loudspeaker-image bisection (LIB) algorithm). Third, two variants of it, exploiting multiple loudspeakers, are proposed. Fourth, we present a direct localization method, the ellipsoid tangent sample consensus (ETSAC), exploiting ellipsoid properties to localize the reflector. Finally, systematic experiments on simulated and measured RIRs are presented, comparing the proposed methods with the state-of-the-art. ETSAC generates errors lower than the alternative methods compared through our datasets. Nevertheless, the ISDAR-LIB combination performs well and has a run time 200 times faster than ETSAC.
[ { "version": "v1", "created": "Tue, 18 Oct 2016 14:48:06 GMT" }, { "version": "v2", "created": "Thu, 5 Jan 2017 13:34:14 GMT" } ]
2017-01-06T00:00:00
[ [ "Remaggi", "Luca", "" ], [ "Jackson", "Philip J. B.", "" ], [ "Coleman", "Philip", "" ], [ "Wang", "Wenwu", "" ] ]
TITLE: Acoustic Reflector Localization: Novel Image Source Reversion and Direct Localization Methods ABSTRACT: Acoustic reflector localization is an important issue in audio signal processing, with direct applications in spatial audio, scene reconstruction, and source separation. Several methods have recently been proposed to estimate the 3D positions of acoustic reflectors given room impulse responses (RIRs). In this article, we categorize these methods as "image-source reversion", which localizes the image source before finding the reflector position, and "direct localization", which localizes the reflector without intermediate steps. We present five new contributions. First, an onset detector, called the clustered dynamic programming projected phase-slope algorithm, is proposed to automatically extract the time of arrival for early reflections within the RIRs of a compact microphone array. Second, we propose an image-source reversion method that uses the RIRs from a single loudspeaker. It is constructed by combining an image source locator (the image source direction and range (ISDAR) algorithm), and a reflector locator (using the loudspeaker-image bisection (LIB) algorithm). Third, two variants of it, exploiting multiple loudspeakers, are proposed. Fourth, we present a direct localization method, the ellipsoid tangent sample consensus (ETSAC), exploiting ellipsoid properties to localize the reflector. Finally, systematic experiments on simulated and measured RIRs are presented, comparing the proposed methods with the state-of-the-art. ETSAC generates errors lower than the alternative methods compared through our datasets. Nevertheless, the ISDAR-LIB combination performs well and has a run time 200 times faster than ETSAC.
no_new_dataset
0.949201
1701.01142
Anastasios Karakostas
Anastasios Karakostas, Alexia Briassouli, Konstantinos Avgerinakis, Ioannis Kompatsiaris, Magda Tsolaki
The Dem@Care Experiments and Datasets: a Technical Report
4pages 2figures
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The objective of Dem@Care is the development of a complete system providing personal health services to people with dementia, as well as medical professionals and caregivers, by using a multitude of sensors, for context-aware, multi-parametric monitoring of lifestyle, ambient environment, and health parameters. Multi-sensor data analysis, combined with intelligent decision making mechanisms, will allow an accurate representation of the person's current status and will provide the appropriate feedback, both to the person and the associated caregivers, enhancing the standard clinical workflow. Within the project framework, several data collection activities have taken place to assist technical development and evaluation tasks. In all these activities, particular attention has been paid to adhere to ethical guidelines and preserve the participants' privacy. This technical report describes shorty the (a) the main objectives of the project, (b) the main ethical principles and (c) the datasets that have been already created.
[ { "version": "v1", "created": "Sat, 17 Dec 2016 19:43:18 GMT" } ]
2017-01-06T00:00:00
[ [ "Karakostas", "Anastasios", "" ], [ "Briassouli", "Alexia", "" ], [ "Avgerinakis", "Konstantinos", "" ], [ "Kompatsiaris", "Ioannis", "" ], [ "Tsolaki", "Magda", "" ] ]
TITLE: The Dem@Care Experiments and Datasets: a Technical Report ABSTRACT: The objective of Dem@Care is the development of a complete system providing personal health services to people with dementia, as well as medical professionals and caregivers, by using a multitude of sensors, for context-aware, multi-parametric monitoring of lifestyle, ambient environment, and health parameters. Multi-sensor data analysis, combined with intelligent decision making mechanisms, will allow an accurate representation of the person's current status and will provide the appropriate feedback, both to the person and the associated caregivers, enhancing the standard clinical workflow. Within the project framework, several data collection activities have taken place to assist technical development and evaluation tasks. In all these activities, particular attention has been paid to adhere to ethical guidelines and preserve the participants' privacy. This technical report describes shorty the (a) the main objectives of the project, (b) the main ethical principles and (c) the datasets that have been already created.
no_new_dataset
0.917598
1701.01218
Mohamed Elhoseiny Mohamed Elhoseiny
Mohamed Elhoseiny and Ahmed Elgammal
Overlapping Cover Local Regression Machines
Long Article with more experiments and analysis of conference paper "Overlapping Domain Cover for Scalable and Accurate Regression Kernel Machines", presented orally 2015 at the British Machine Vision Conference 2015 (BMVC)
null
null
null
cs.LG cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present the Overlapping Domain Cover (ODC) notion for kernel machines, as a set of overlapping subsets of the data that covers the entire training set and optimized to be spatially cohesive as possible. We show how this notion benefit the speed of local kernel machines for regression in terms of both speed while achieving while minimizing the prediction error. We propose an efficient ODC framework, which is applicable to various regression models and in particular reduces the complexity of Twin Gaussian Processes (TGP) regression from cubic to quadratic. Our notion is also applicable to several kernel methods (e.g., Gaussian Process Regression(GPR) and IWTGP regression, as shown in our experiments). We also theoretically justified the idea behind our method to improve local prediction by the overlapping cover. We validated and analyzed our method on three benchmark human pose estimation datasets and interesting findings are discussed.
[ { "version": "v1", "created": "Thu, 5 Jan 2017 06:04:53 GMT" } ]
2017-01-06T00:00:00
[ [ "Elhoseiny", "Mohamed", "" ], [ "Elgammal", "Ahmed", "" ] ]
TITLE: Overlapping Cover Local Regression Machines ABSTRACT: We present the Overlapping Domain Cover (ODC) notion for kernel machines, as a set of overlapping subsets of the data that covers the entire training set and optimized to be spatially cohesive as possible. We show how this notion benefit the speed of local kernel machines for regression in terms of both speed while achieving while minimizing the prediction error. We propose an efficient ODC framework, which is applicable to various regression models and in particular reduces the complexity of Twin Gaussian Processes (TGP) regression from cubic to quadratic. Our notion is also applicable to several kernel methods (e.g., Gaussian Process Regression(GPR) and IWTGP regression, as shown in our experiments). We also theoretically justified the idea behind our method to improve local prediction by the overlapping cover. We validated and analyzed our method on three benchmark human pose estimation datasets and interesting findings are discussed.
no_new_dataset
0.950041
1701.01232
Dinusha Vatsalan
Dinusha Vatsalan, Peter Christen, and Erhard Rahm
Scalable Multi-Database Privacy-Preserving Record Linkage using Counting Bloom Filters
This is an extended version of an article published in IEEE ICDM International Workshop on Privacy and Discrimination in Data Mining (PDDM) 2016 - Scalable privacy-preserving linking of multiple databases using counting Bloom filters
null
null
null
cs.DB
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Privacy-preserving record linkage (PPRL) aims at integrating sensitive information from multiple disparate databases of different organizations. PPRL approaches are increasingly required in real-world application areas such as healthcare, national security, and business. Previous approaches have mostly focused on linking only two databases as well as the use of a dedicated linkage unit. Scaling PPRL to more databases (multi-party PPRL) is an open challenge since privacy threats as well as the computation and communication costs for record linkage increase significantly with the number of databases. We thus propose the use of a new encoding method of sensitive data based on Counting Bloom Filters (CBF) to improve privacy for multi-party PPRL. We also investigate optimizations to reduce communication and computation costs for CBF-based multi-party PPRL with and without the use of a dedicated linkage unit. Empirical evaluations conducted with real datasets show the viability of the proposed approaches and demonstrate their scalability, linkage quality, and privacy protection.
[ { "version": "v1", "created": "Thu, 5 Jan 2017 07:57:55 GMT" } ]
2017-01-06T00:00:00
[ [ "Vatsalan", "Dinusha", "" ], [ "Christen", "Peter", "" ], [ "Rahm", "Erhard", "" ] ]
TITLE: Scalable Multi-Database Privacy-Preserving Record Linkage using Counting Bloom Filters ABSTRACT: Privacy-preserving record linkage (PPRL) aims at integrating sensitive information from multiple disparate databases of different organizations. PPRL approaches are increasingly required in real-world application areas such as healthcare, national security, and business. Previous approaches have mostly focused on linking only two databases as well as the use of a dedicated linkage unit. Scaling PPRL to more databases (multi-party PPRL) is an open challenge since privacy threats as well as the computation and communication costs for record linkage increase significantly with the number of databases. We thus propose the use of a new encoding method of sensitive data based on Counting Bloom Filters (CBF) to improve privacy for multi-party PPRL. We also investigate optimizations to reduce communication and computation costs for CBF-based multi-party PPRL with and without the use of a dedicated linkage unit. Empirical evaluations conducted with real datasets show the viability of the proposed approaches and demonstrate their scalability, linkage quality, and privacy protection.
no_new_dataset
0.944689
1701.01250
Jun Wang
Jun Wang and Qiang Tang
A Probabilistic View of Neighborhood-based Recommendation Methods
accepted by: ICDM 2016 - IEEE International Conference on Data Mining series (ICDM) workshop CLOUDMINE, 7 pages
null
null
null
cs.IR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Probabilistic graphic model is an elegant framework to compactly present complex real-world observations by modeling uncertainty and logical flow (conditionally independent factors). In this paper, we present a probabilistic framework of neighborhood-based recommendation methods (PNBM) in which similarity is regarded as an unobserved factor. Thus, PNBM leads the estimation of user preference to maximizing a posterior over similarity. We further introduce a novel multi-layer similarity descriptor which models and learns the joint influence of various features under PNBM, and name the new framework MPNBM. Empirical results on real-world datasets show that MPNBM allows very accurate estimation of user preferences.
[ { "version": "v1", "created": "Thu, 5 Jan 2017 08:53:02 GMT" } ]
2017-01-06T00:00:00
[ [ "Wang", "Jun", "" ], [ "Tang", "Qiang", "" ] ]
TITLE: A Probabilistic View of Neighborhood-based Recommendation Methods ABSTRACT: Probabilistic graphic model is an elegant framework to compactly present complex real-world observations by modeling uncertainty and logical flow (conditionally independent factors). In this paper, we present a probabilistic framework of neighborhood-based recommendation methods (PNBM) in which similarity is regarded as an unobserved factor. Thus, PNBM leads the estimation of user preference to maximizing a posterior over similarity. We further introduce a novel multi-layer similarity descriptor which models and learns the joint influence of various features under PNBM, and name the new framework MPNBM. Empirical results on real-world datasets show that MPNBM allows very accurate estimation of user preferences.
no_new_dataset
0.943764
1701.01276
Dominik Kowald
Dominik Kowald, Subhash Pujari, Elisabeth Lex
Temporal Effects on Hashtag Reuse in Twitter: A Cognitive-Inspired Hashtag Recommendation Approach
Accepted at WWW 2017
null
null
null
cs.IR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Hashtags have become a powerful tool in social platforms such as Twitter to categorize and search for content, and to spread short messages across members of the social network. In this paper, we study temporal hashtag usage practices in Twitter with the aim of designing a cognitive-inspired hashtag recommendation algorithm we call BLLi,s. Our main idea is to incorporate the effect of time on (i) individual hashtag reuse (i.e., reusing own hashtags), and (ii) social hashtag reuse (i.e., reusing hashtags, which has been previously used by a followee) into a predictive model. For this, we turn to the Base-Level Learning (BLL) equation from the cognitive architecture ACT-R, which accounts for the time-dependent decay of item exposure in human memory. We validate BLLi,s using two crawled Twitter datasets in two evaluation scenarios: firstly, only temporal usage patterns of past hashtag assignments are utilized and secondly, these patterns are combined with a content-based analysis of the current tweet. In both scenarios, we find not only that temporal effects play an important role for both individual and social hashtag reuse but also that BLLi,s provides significantly better prediction accuracy and ranking results than current state-of-the-art hashtag recommendation methods.
[ { "version": "v1", "created": "Thu, 5 Jan 2017 11:07:16 GMT" } ]
2017-01-06T00:00:00
[ [ "Kowald", "Dominik", "" ], [ "Pujari", "Subhash", "" ], [ "Lex", "Elisabeth", "" ] ]
TITLE: Temporal Effects on Hashtag Reuse in Twitter: A Cognitive-Inspired Hashtag Recommendation Approach ABSTRACT: Hashtags have become a powerful tool in social platforms such as Twitter to categorize and search for content, and to spread short messages across members of the social network. In this paper, we study temporal hashtag usage practices in Twitter with the aim of designing a cognitive-inspired hashtag recommendation algorithm we call BLLi,s. Our main idea is to incorporate the effect of time on (i) individual hashtag reuse (i.e., reusing own hashtags), and (ii) social hashtag reuse (i.e., reusing hashtags, which has been previously used by a followee) into a predictive model. For this, we turn to the Base-Level Learning (BLL) equation from the cognitive architecture ACT-R, which accounts for the time-dependent decay of item exposure in human memory. We validate BLLi,s using two crawled Twitter datasets in two evaluation scenarios: firstly, only temporal usage patterns of past hashtag assignments are utilized and secondly, these patterns are combined with a content-based analysis of the current tweet. In both scenarios, we find not only that temporal effects play an important role for both individual and social hashtag reuse but also that BLLi,s provides significantly better prediction accuracy and ranking results than current state-of-the-art hashtag recommendation methods.
no_new_dataset
0.949809
1612.01848
Aaditya Prakash
Aaditya Prakash, Siyuan Zhao, Sadid A. Hasan, Vivek Datla, Kathy Lee, Ashequl Qadir, Joey Liu, Oladimeji Farri
Condensed Memory Networks for Clinical Diagnostic Inferencing
Accepted to AAAI 2017
null
null
null
cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Diagnosis of a clinical condition is a challenging task, which often requires significant medical investigation. Previous work related to diagnostic inferencing problems mostly consider multivariate observational data (e.g. physiological signals, lab tests etc.). In contrast, we explore the problem using free-text medical notes recorded in an electronic health record (EHR). Complex tasks like these can benefit from structured knowledge bases, but those are not scalable. We instead exploit raw text from Wikipedia as a knowledge source. Memory networks have been demonstrated to be effective in tasks which require comprehension of free-form text. They use the final iteration of the learned representation to predict probable classes. We introduce condensed memory neural networks (C-MemNNs), a novel model with iterative condensation of memory representations that preserves the hierarchy of features in the memory. Experiments on the MIMIC-III dataset show that the proposed model outperforms other variants of memory networks to predict the most probable diagnoses given a complex clinical scenario.
[ { "version": "v1", "created": "Tue, 6 Dec 2016 15:15:27 GMT" }, { "version": "v2", "created": "Tue, 3 Jan 2017 20:41:20 GMT" } ]
2017-01-05T00:00:00
[ [ "Prakash", "Aaditya", "" ], [ "Zhao", "Siyuan", "" ], [ "Hasan", "Sadid A.", "" ], [ "Datla", "Vivek", "" ], [ "Lee", "Kathy", "" ], [ "Qadir", "Ashequl", "" ], [ "Liu", "Joey", "" ], [ "Farri", "Oladimeji", "" ] ]
TITLE: Condensed Memory Networks for Clinical Diagnostic Inferencing ABSTRACT: Diagnosis of a clinical condition is a challenging task, which often requires significant medical investigation. Previous work related to diagnostic inferencing problems mostly consider multivariate observational data (e.g. physiological signals, lab tests etc.). In contrast, we explore the problem using free-text medical notes recorded in an electronic health record (EHR). Complex tasks like these can benefit from structured knowledge bases, but those are not scalable. We instead exploit raw text from Wikipedia as a knowledge source. Memory networks have been demonstrated to be effective in tasks which require comprehension of free-form text. They use the final iteration of the learned representation to predict probable classes. We introduce condensed memory neural networks (C-MemNNs), a novel model with iterative condensation of memory representations that preserves the hierarchy of features in the memory. Experiments on the MIMIC-III dataset show that the proposed model outperforms other variants of memory networks to predict the most probable diagnoses given a complex clinical scenario.
no_new_dataset
0.949295
1701.00831
Alessandro Rossi
Marco Gori, Marco Maggini, Alessandro Rossi
Collapsing of dimensionality
null
null
null
null
cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyze a new approach to Machine Learning coming from a modification of classical regularization networks by casting the process in the time dimension, leading to a sort of collapse of dimensionality in the problem of learning the model parameters. This approach allows the definition of a online learning algorithm that progressively accumulates the knowledge provided in the input trajectory. The regularization principle leads to a solution based on a dynamical system that is paired with a procedure to develop a graph structure that stores the input regularities acquired from the temporal evolution. We report an extensive experimental exploration on the behavior of the parameter of the proposed model and an evaluation on artificial dataset.
[ { "version": "v1", "created": "Tue, 3 Jan 2017 20:54:52 GMT" } ]
2017-01-05T00:00:00
[ [ "Gori", "Marco", "" ], [ "Maggini", "Marco", "" ], [ "Rossi", "Alessandro", "" ] ]
TITLE: Collapsing of dimensionality ABSTRACT: We analyze a new approach to Machine Learning coming from a modification of classical regularization networks by casting the process in the time dimension, leading to a sort of collapse of dimensionality in the problem of learning the model parameters. This approach allows the definition of a online learning algorithm that progressively accumulates the knowledge provided in the input trajectory. The regularization principle leads to a solution based on a dynamical system that is paired with a procedure to develop a graph structure that stores the input regularities acquired from the temporal evolution. We report an extensive experimental exploration on the behavior of the parameter of the proposed model and an evaluation on artificial dataset.
no_new_dataset
0.947186
1701.00893
Jorge Luis Rivero
Jorge Luis Rivero P\'erez, Bernardete Ribeiro, Kadir Hector Ortiz
A Comparison of Algorithms for Intrusion Detection on Batch and Data Stream Environments
in Spanish
null
null
null
cs.DS
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Intruders detection in computer networks has some deficiencies from machine learning approach, given by the nature of the application. The principal problem is the modest display of detection systems based on learning algorithms under the constraints imposed by real environments. This article focuses on the machine learning approach for network intrusion detection in batch and data stream environments. First, we propose and describe three variants of KDD99 dataset preprocessing including attribute selection. Secondly, a thoroughly experimentation is performed from evaluating and comparing representative batch learning algorithms on the variants obtained from KDD99 pre processing. Finally, since network traffic is a constant data stream, which can present concept drifting with high rate of false positive, along with the fact that there are not many researches addressing intrusion detection on streaming environments, lead us to make a comparison of various representative data stream classification algorithms. This research allows determining the algorithms that better perform on the proposed variants of KDD99 for both batch and data stream environments.
[ { "version": "v1", "created": "Wed, 4 Jan 2017 03:55:55 GMT" } ]
2017-01-05T00:00:00
[ [ "Pérez", "Jorge Luis Rivero", "" ], [ "Ribeiro", "Bernardete", "" ], [ "Ortiz", "Kadir Hector", "" ] ]
TITLE: A Comparison of Algorithms for Intrusion Detection on Batch and Data Stream Environments ABSTRACT: Intruders detection in computer networks has some deficiencies from machine learning approach, given by the nature of the application. The principal problem is the modest display of detection systems based on learning algorithms under the constraints imposed by real environments. This article focuses on the machine learning approach for network intrusion detection in batch and data stream environments. First, we propose and describe three variants of KDD99 dataset preprocessing including attribute selection. Secondly, a thoroughly experimentation is performed from evaluating and comparing representative batch learning algorithms on the variants obtained from KDD99 pre processing. Finally, since network traffic is a constant data stream, which can present concept drifting with high rate of false positive, along with the fact that there are not many researches addressing intrusion detection on streaming environments, lead us to make a comparison of various representative data stream classification algorithms. This research allows determining the algorithms that better perform on the proposed variants of KDD99 for both batch and data stream environments.
no_new_dataset
0.947866
1701.00903
Lakshmi Narasimhan Govindarajan
Li Liu and Yongzhong Yang and Lakshmi Narasimhan Govindarajan and Shu Wang and Bin Hu and Li Cheng and David S. Rosenblum
An Interval-Based Bayesian Generative Model for Human Complex Activity Recognition
null
null
null
null
stat.ML cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Complex activity recognition is challenging due to the inherent uncertainty and diversity of performing a complex activity. Normally, each instance of a complex activity has its own configuration of atomic actions and their temporal dependencies. We propose in this paper an atomic action-based Bayesian model that constructs Allen's interval relation networks to characterize complex activities with structural varieties in a probabilistic generative way: By introducing latent variables from the Chinese restaurant process, our approach is able to capture all possible styles of a particular complex activity as a unique set of distributions over atomic actions and relations. We also show that local temporal dependencies can be retained and are globally consistent in the resulting interval network. Moreover, network structure can be learned from empirical data. A new dataset of complex hand activities has been constructed and made publicly available, which is much larger in size than any existing datasets. Empirical evaluations on benchmark datasets as well as our in-house dataset demonstrate the competitiveness of our approach.
[ { "version": "v1", "created": "Wed, 4 Jan 2017 05:53:46 GMT" } ]
2017-01-05T00:00:00
[ [ "Liu", "Li", "" ], [ "Yang", "Yongzhong", "" ], [ "Govindarajan", "Lakshmi Narasimhan", "" ], [ "Wang", "Shu", "" ], [ "Hu", "Bin", "" ], [ "Cheng", "Li", "" ], [ "Rosenblum", "David S.", "" ] ]
TITLE: An Interval-Based Bayesian Generative Model for Human Complex Activity Recognition ABSTRACT: Complex activity recognition is challenging due to the inherent uncertainty and diversity of performing a complex activity. Normally, each instance of a complex activity has its own configuration of atomic actions and their temporal dependencies. We propose in this paper an atomic action-based Bayesian model that constructs Allen's interval relation networks to characterize complex activities with structural varieties in a probabilistic generative way: By introducing latent variables from the Chinese restaurant process, our approach is able to capture all possible styles of a particular complex activity as a unique set of distributions over atomic actions and relations. We also show that local temporal dependencies can be retained and are globally consistent in the resulting interval network. Moreover, network structure can be learned from empirical data. A new dataset of complex hand activities has been constructed and made publicly available, which is much larger in size than any existing datasets. Empirical evaluations on benchmark datasets as well as our in-house dataset demonstrate the competitiveness of our approach.
new_dataset
0.959307
1701.01094
Karamjit Singh
Karamjit Singh, Garima Gupta, Gautam Shroff, and Puneet Agarwal
Minimally-Supervised Attribute Fusion for Data Lakes
null
null
null
null
cs.DB
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Aggregate analysis, such as comparing country-wise sales versus global market share across product categories, is often complicated by the unavailability of common join attributes, e.g., category, across diverse datasets from different geographies or retail chains, even after disparate data is technically ingested into a common data lake. Sometimes this is a missing data issue, while in other cases it may be inherent, e.g., the records in different geographical databases may actually describe different product 'SKUs', or follow different norms for categorization. Record linkage techniques can be used to automatically map products in different data sources to a common set of global attributes, thereby enabling federated aggregation joins to be performed. Traditional record-linkage techniques are typically unsupervised, relying textual similarity features across attributes to estimate matches. In this paper, we present an ensemble model combining minimal supervision using Bayesian network models together with unsupervised textual matching for automating such 'attribute fusion'. We present results of our approach on a large volume of real-life data from a market-research scenario and compare with a standard record matching algorithm. Finally we illustrate how attribute fusion using machine learning could be included as a data-lake management feature, especially as our approach also provides confidence values for matches, enabling human intervention, if required.
[ { "version": "v1", "created": "Wed, 4 Jan 2017 18:19:19 GMT" } ]
2017-01-05T00:00:00
[ [ "Singh", "Karamjit", "" ], [ "Gupta", "Garima", "" ], [ "Shroff", "Gautam", "" ], [ "Agarwal", "Puneet", "" ] ]
TITLE: Minimally-Supervised Attribute Fusion for Data Lakes ABSTRACT: Aggregate analysis, such as comparing country-wise sales versus global market share across product categories, is often complicated by the unavailability of common join attributes, e.g., category, across diverse datasets from different geographies or retail chains, even after disparate data is technically ingested into a common data lake. Sometimes this is a missing data issue, while in other cases it may be inherent, e.g., the records in different geographical databases may actually describe different product 'SKUs', or follow different norms for categorization. Record linkage techniques can be used to automatically map products in different data sources to a common set of global attributes, thereby enabling federated aggregation joins to be performed. Traditional record-linkage techniques are typically unsupervised, relying textual similarity features across attributes to estimate matches. In this paper, we present an ensemble model combining minimal supervision using Bayesian network models together with unsupervised textual matching for automating such 'attribute fusion'. We present results of our approach on a large volume of real-life data from a market-research scenario and compare with a standard record matching algorithm. Finally we illustrate how attribute fusion using machine learning could be included as a data-lake management feature, especially as our approach also provides confidence values for matches, enabling human intervention, if required.
no_new_dataset
0.947962
1604.02646
Biswajit Paria
Biswajit Paria, Vikas Reddy, Anirban Santara, Pabitra Mitra
Visualization Regularizers for Neural Network based Image Recognition
null
null
null
null
cs.LG cs.CV cs.NE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The success of deep neural networks is mostly due their ability to learn meaningful features from the data. Features learned in the hidden layers of deep neural networks trained in computer vision tasks have been shown to be similar to mid-level vision features. We leverage this fact in this work and propose the visualization regularizer for image tasks. The proposed regularization technique enforces smoothness of the features learned by hidden nodes and turns out to be a special case of Tikhonov regularization. We achieve higher classification accuracy as compared to existing regularizers such as the L2 norm regularizer and dropout, on benchmark datasets without changing the training computational complexity.
[ { "version": "v1", "created": "Sun, 10 Apr 2016 07:02:40 GMT" }, { "version": "v2", "created": "Sun, 15 May 2016 14:38:38 GMT" }, { "version": "v3", "created": "Tue, 3 Jan 2017 10:07:22 GMT" } ]
2017-01-04T00:00:00
[ [ "Paria", "Biswajit", "" ], [ "Reddy", "Vikas", "" ], [ "Santara", "Anirban", "" ], [ "Mitra", "Pabitra", "" ] ]
TITLE: Visualization Regularizers for Neural Network based Image Recognition ABSTRACT: The success of deep neural networks is mostly due their ability to learn meaningful features from the data. Features learned in the hidden layers of deep neural networks trained in computer vision tasks have been shown to be similar to mid-level vision features. We leverage this fact in this work and propose the visualization regularizer for image tasks. The proposed regularization technique enforces smoothness of the features learned by hidden nodes and turns out to be a special case of Tikhonov regularization. We achieve higher classification accuracy as compared to existing regularizers such as the L2 norm regularizer and dropout, on benchmark datasets without changing the training computational complexity.
no_new_dataset
0.950869
1607.06997
Xiangyun Zhao
Xiangyun Zhao, Xiaodan Liang, Luoqi Liu, Teng Li, Yugang Han, Nuno Vasconcelos, Shuicheng Yan
Peak-Piloted Deep Network for Facial Expression Recognition
Published in ECCV 2016
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Objective functions for training of deep networks for face-related recognition tasks, such as facial expression recognition (FER), usually consider each sample independently. In this work, we present a novel peak-piloted deep network (PPDN) that uses a sample with peak expression (easy sample) to supervise the intermediate feature responses for a sample of non-peak expression (hard sample) of the same type and from the same subject. The expression evolving process from non-peak expression to peak expression can thus be implicitly embedded in the network to achieve the invariance to expression intensities. A special purpose back-propagation procedure, peak gradient suppression (PGS), is proposed for network training. It drives the intermediate-layer feature responses of non-peak expression samples towards those of the corresponding peak expression samples, while avoiding the inverse. This avoids degrading the recognition capability for samples of peak expression due to interference from their non-peak expression counterparts. Extensive comparisons on two popular FER datasets, Oulu-CASIA and CK+, demonstrate the superiority of the PPDN over state-ofthe-art FER methods, as well as the advantages of both the network structure and the optimization strategy. Moreover, it is shown that PPDN is a general architecture, extensible to other tasks by proper definition of peak and non-peak samples. This is validated by experiments that show state-of-the-art performance on pose-invariant face recognition, using the Multi-PIE dataset.
[ { "version": "v1", "created": "Sun, 24 Jul 2016 04:26:41 GMT" }, { "version": "v2", "created": "Tue, 3 Jan 2017 08:19:24 GMT" } ]
2017-01-04T00:00:00
[ [ "Zhao", "Xiangyun", "" ], [ "Liang", "Xiaodan", "" ], [ "Liu", "Luoqi", "" ], [ "Li", "Teng", "" ], [ "Han", "Yugang", "" ], [ "Vasconcelos", "Nuno", "" ], [ "Yan", "Shuicheng", "" ] ]
TITLE: Peak-Piloted Deep Network for Facial Expression Recognition ABSTRACT: Objective functions for training of deep networks for face-related recognition tasks, such as facial expression recognition (FER), usually consider each sample independently. In this work, we present a novel peak-piloted deep network (PPDN) that uses a sample with peak expression (easy sample) to supervise the intermediate feature responses for a sample of non-peak expression (hard sample) of the same type and from the same subject. The expression evolving process from non-peak expression to peak expression can thus be implicitly embedded in the network to achieve the invariance to expression intensities. A special purpose back-propagation procedure, peak gradient suppression (PGS), is proposed for network training. It drives the intermediate-layer feature responses of non-peak expression samples towards those of the corresponding peak expression samples, while avoiding the inverse. This avoids degrading the recognition capability for samples of peak expression due to interference from their non-peak expression counterparts. Extensive comparisons on two popular FER datasets, Oulu-CASIA and CK+, demonstrate the superiority of the PPDN over state-ofthe-art FER methods, as well as the advantages of both the network structure and the optimization strategy. Moreover, it is shown that PPDN is a general architecture, extensible to other tasks by proper definition of peak and non-peak samples. This is validated by experiments that show state-of-the-art performance on pose-invariant face recognition, using the Multi-PIE dataset.
no_new_dataset
0.947527
1701.00576
Huijia Wu
Huijia Wu, Jiajun Zhang, Chengqing Zong
Shortcut Sequence Tagging
10 pages. arXiv admin note: text overlap with arXiv:1610.03167
null
null
null
cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Deep stacked RNNs are usually hard to train. Adding shortcut connections across different layers is a common way to ease the training of stacked networks. However, extra shortcuts make the recurrent step more complicated. To simply the stacked architecture, we propose a framework called shortcut block, which is a marriage of the gating mechanism and shortcuts, while discarding the self-connected part in LSTM cell. We present extensive empirical experiments showing that this design makes training easy and improves generalization. We propose various shortcut block topologies and compositions to explore its effectiveness. Based on this architecture, we obtain a 6% relatively improvement over the state-of-the-art on CCGbank supertagging dataset. We also get comparable results on POS tagging task.
[ { "version": "v1", "created": "Tue, 3 Jan 2017 04:15:51 GMT" } ]
2017-01-04T00:00:00
[ [ "Wu", "Huijia", "" ], [ "Zhang", "Jiajun", "" ], [ "Zong", "Chengqing", "" ] ]
TITLE: Shortcut Sequence Tagging ABSTRACT: Deep stacked RNNs are usually hard to train. Adding shortcut connections across different layers is a common way to ease the training of stacked networks. However, extra shortcuts make the recurrent step more complicated. To simply the stacked architecture, we propose a framework called shortcut block, which is a marriage of the gating mechanism and shortcuts, while discarding the self-connected part in LSTM cell. We present extensive empirical experiments showing that this design makes training easy and improves generalization. We propose various shortcut block topologies and compositions to explore its effectiveness. Based on this architecture, we obtain a 6% relatively improvement over the state-of-the-art on CCGbank supertagging dataset. We also get comparable results on POS tagging task.
no_new_dataset
0.946941
1701.00595
Saeid Hosseini
Saeid Hosseini, Hongzhi Yin, Xiaofang Zhou, Shazia Sadiq
Leveraging Multi-aspect Time-related Influence in Location Recommendation
null
null
null
null
cs.CY cs.IR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Point-Of-Interest (POI) recommendation aims to mine a user's visiting history and find her/his potentially preferred places. Although location recommendation methods have been studied and improved pervasively, the challenges w.r.t employing various influences including temporal aspect still remain. Inspired by the fact that time includes numerous granular slots (e.g. minute, hour, day, week and etc.), in this paper, we define a new problem to perform recommendation through exploiting all diversified temporal factors. In particular, we argue that most existing methods only focus on a limited number of time-related features and neglect others. Furthermore, considering a specific granularity (e.g. time of a day) in recommendation cannot always apply to each user or each dataset. To address the challenges, we propose a probabilistic generative model, named after Multi-aspect Time-related Influence (MATI) to promote POI recommendation. We also develop a novel optimization algorithm based on Expectation Maximization (EM). Our MATI model firstly detects a user's temporal multivariate orientation using her check-in log in Location-based Social Networks(LBSNs). It then performs recommendation using temporal correlations between the user and proposed locations. Our method is adaptable to various types of recommendation systems and can work efficiently in multiple time-scales. Extensive experimental results on two large-scale LBSN datasets verify the effectiveness of our method over other competitors.
[ { "version": "v1", "created": "Tue, 3 Jan 2017 06:50:50 GMT" } ]
2017-01-04T00:00:00
[ [ "Hosseini", "Saeid", "" ], [ "Yin", "Hongzhi", "" ], [ "Zhou", "Xiaofang", "" ], [ "Sadiq", "Shazia", "" ] ]
TITLE: Leveraging Multi-aspect Time-related Influence in Location Recommendation ABSTRACT: Point-Of-Interest (POI) recommendation aims to mine a user's visiting history and find her/his potentially preferred places. Although location recommendation methods have been studied and improved pervasively, the challenges w.r.t employing various influences including temporal aspect still remain. Inspired by the fact that time includes numerous granular slots (e.g. minute, hour, day, week and etc.), in this paper, we define a new problem to perform recommendation through exploiting all diversified temporal factors. In particular, we argue that most existing methods only focus on a limited number of time-related features and neglect others. Furthermore, considering a specific granularity (e.g. time of a day) in recommendation cannot always apply to each user or each dataset. To address the challenges, we propose a probabilistic generative model, named after Multi-aspect Time-related Influence (MATI) to promote POI recommendation. We also develop a novel optimization algorithm based on Expectation Maximization (EM). Our MATI model firstly detects a user's temporal multivariate orientation using her check-in log in Location-based Social Networks(LBSNs). It then performs recommendation using temporal correlations between the user and proposed locations. Our method is adaptable to various types of recommendation systems and can work efficiently in multiple time-scales. Extensive experimental results on two large-scale LBSN datasets verify the effectiveness of our method over other competitors.
no_new_dataset
0.946843
1607.04579
Bo Dai
Bo Dai, Niao He, Yunpeng Pan, Byron Boots, Le Song
Learning from Conditional Distributions via Dual Embeddings
24 pages, 11 figures
null
null
null
cs.LG math.OC stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Many machine learning tasks, such as learning with invariance and policy evaluation in reinforcement learning, can be characterized as problems of learning from conditional distributions. In such problems, each sample $x$ itself is associated with a conditional distribution $p(z|x)$ represented by samples $\{z_i\}_{i=1}^M$, and the goal is to learn a function $f$ that links these conditional distributions to target values $y$. These learning problems become very challenging when we only have limited samples or in the extreme case only one sample from each conditional distribution. Commonly used approaches either assume that $z$ is independent of $x$, or require an overwhelmingly large samples from each conditional distribution. To address these challenges, we propose a novel approach which employs a new min-max reformulation of the learning from conditional distribution problem. With such new reformulation, we only need to deal with the joint distribution $p(z,x)$. We also design an efficient learning algorithm, Embedding-SGD, and establish theoretical sample complexity for such problems. Finally, our numerical experiments on both synthetic and real-world datasets show that the proposed approach can significantly improve over the existing algorithms.
[ { "version": "v1", "created": "Fri, 15 Jul 2016 16:56:22 GMT" }, { "version": "v2", "created": "Sat, 31 Dec 2016 06:54:37 GMT" } ]
2017-01-03T00:00:00
[ [ "Dai", "Bo", "" ], [ "He", "Niao", "" ], [ "Pan", "Yunpeng", "" ], [ "Boots", "Byron", "" ], [ "Song", "Le", "" ] ]
TITLE: Learning from Conditional Distributions via Dual Embeddings ABSTRACT: Many machine learning tasks, such as learning with invariance and policy evaluation in reinforcement learning, can be characterized as problems of learning from conditional distributions. In such problems, each sample $x$ itself is associated with a conditional distribution $p(z|x)$ represented by samples $\{z_i\}_{i=1}^M$, and the goal is to learn a function $f$ that links these conditional distributions to target values $y$. These learning problems become very challenging when we only have limited samples or in the extreme case only one sample from each conditional distribution. Commonly used approaches either assume that $z$ is independent of $x$, or require an overwhelmingly large samples from each conditional distribution. To address these challenges, we propose a novel approach which employs a new min-max reformulation of the learning from conditional distribution problem. With such new reformulation, we only need to deal with the joint distribution $p(z,x)$. We also design an efficient learning algorithm, Embedding-SGD, and establish theoretical sample complexity for such problems. Finally, our numerical experiments on both synthetic and real-world datasets show that the proposed approach can significantly improve over the existing algorithms.
no_new_dataset
0.941007
1612.02287
Frank Michel
Frank Michel, Alexander Kirillov, Eric Brachmann, Alexander Krull, Stefan Gumhold, Bogdan Savchynskyy, Carsten Rother
Global Hypothesis Generation for 6D Object Pose Estimation
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper addresses the task of estimating the 6D pose of a known 3D object from a single RGB-D image. Most modern approaches solve this task in three steps: i) Compute local features; ii) Generate a pool of pose-hypotheses; iii) Select and refine a pose from the pool. This work focuses on the second step. While all existing approaches generate the hypotheses pool via local reasoning, e.g. RANSAC or Hough-voting, we are the first to show that global reasoning is beneficial at this stage. In particular, we formulate a novel fully-connected Conditional Random Field (CRF) that outputs a very small number of pose-hypotheses. Despite the potential functions of the CRF being non-Gaussian, we give a new and efficient two-step optimization procedure, with some guarantees for optimality. We utilize our global hypotheses generation procedure to produce results that exceed state-of-the-art for the challenging "Occluded Object Dataset".
[ { "version": "v1", "created": "Wed, 7 Dec 2016 15:23:12 GMT" }, { "version": "v2", "created": "Thu, 8 Dec 2016 08:50:37 GMT" }, { "version": "v3", "created": "Mon, 2 Jan 2017 09:09:03 GMT" } ]
2017-01-03T00:00:00
[ [ "Michel", "Frank", "" ], [ "Kirillov", "Alexander", "" ], [ "Brachmann", "Eric", "" ], [ "Krull", "Alexander", "" ], [ "Gumhold", "Stefan", "" ], [ "Savchynskyy", "Bogdan", "" ], [ "Rother", "Carsten", "" ] ]
TITLE: Global Hypothesis Generation for 6D Object Pose Estimation ABSTRACT: This paper addresses the task of estimating the 6D pose of a known 3D object from a single RGB-D image. Most modern approaches solve this task in three steps: i) Compute local features; ii) Generate a pool of pose-hypotheses; iii) Select and refine a pose from the pool. This work focuses on the second step. While all existing approaches generate the hypotheses pool via local reasoning, e.g. RANSAC or Hough-voting, we are the first to show that global reasoning is beneficial at this stage. In particular, we formulate a novel fully-connected Conditional Random Field (CRF) that outputs a very small number of pose-hypotheses. Despite the potential functions of the CRF being non-Gaussian, we give a new and efficient two-step optimization procedure, with some guarantees for optimality. We utilize our global hypotheses generation procedure to produce results that exceed state-of-the-art for the challenging "Occluded Object Dataset".
no_new_dataset
0.94699
1612.05322
Yutong Zheng
Yutong Zheng, Chenchen Zhu, Khoa Luu, Chandrasekhar Bhagavatula, T. Hoang Ngan Le, Marios Savvides
Towards a Deep Learning Framework for Unconstrained Face Detection
Accepted by BTAS 2016. arXiv admin note: substantial text overlap with arXiv:1606.05413
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Robust face detection is one of the most important pre-processing steps to support facial expression analysis, facial landmarking, face recognition, pose estimation, building of 3D facial models, etc. Although this topic has been intensely studied for decades, it is still challenging due to numerous variants of face images in real-world scenarios. In this paper, we present a novel approach named Multiple Scale Faster Region-based Convolutional Neural Network (MS-FRCNN) to robustly detect human facial regions from images collected under various challenging conditions, e.g. large occlusions, extremely low resolutions, facial expressions, strong illumination variations, etc. The proposed approach is benchmarked on two challenging face detection databases, i.e. the Wider Face database and the Face Detection Dataset and Benchmark (FDDB), and compared against recent other face detection methods, e.g. Two-stage CNN, Multi-scale Cascade CNN, Faceness, Aggregate Chanel Features, HeadHunter, Multi-view Face Detection, Cascade CNN, etc. The experimental results show that our proposed approach consistently achieves highly competitive results with the state-of-the-art performance against other recent face detection methods.
[ { "version": "v1", "created": "Fri, 16 Dec 2016 00:34:06 GMT" }, { "version": "v2", "created": "Mon, 2 Jan 2017 18:06:49 GMT" } ]
2017-01-03T00:00:00
[ [ "Zheng", "Yutong", "" ], [ "Zhu", "Chenchen", "" ], [ "Luu", "Khoa", "" ], [ "Bhagavatula", "Chandrasekhar", "" ], [ "Le", "T. Hoang Ngan", "" ], [ "Savvides", "Marios", "" ] ]
TITLE: Towards a Deep Learning Framework for Unconstrained Face Detection ABSTRACT: Robust face detection is one of the most important pre-processing steps to support facial expression analysis, facial landmarking, face recognition, pose estimation, building of 3D facial models, etc. Although this topic has been intensely studied for decades, it is still challenging due to numerous variants of face images in real-world scenarios. In this paper, we present a novel approach named Multiple Scale Faster Region-based Convolutional Neural Network (MS-FRCNN) to robustly detect human facial regions from images collected under various challenging conditions, e.g. large occlusions, extremely low resolutions, facial expressions, strong illumination variations, etc. The proposed approach is benchmarked on two challenging face detection databases, i.e. the Wider Face database and the Face Detection Dataset and Benchmark (FDDB), and compared against recent other face detection methods, e.g. Two-stage CNN, Multi-scale Cascade CNN, Faceness, Aggregate Chanel Features, HeadHunter, Multi-view Face Detection, Cascade CNN, etc. The experimental results show that our proposed approach consistently achieves highly competitive results with the state-of-the-art performance against other recent face detection methods.
no_new_dataset
0.944382
1701.00040
Emmanuel Osegi
E.N. Osegi
p-DLA: A Predictive System Model for Onshore Oil and Gas Pipeline Dataset Classification and Monitoring - Part 1
Working Paper
null
null
null
cs.CV
http://creativecommons.org/licenses/by-nc-sa/4.0/
With the rise in militant activity and rogue behaviour in oil and gas regions around the world, oil pipeline disturbances is on the increase leading to huge losses to multinational operators and the countries where such facilities exist. However, this situation can be averted if adequate predictive monitoring schemes are put in place. We propose in the first part of this paper, an artificial intelligence predictive monitoring system capable of predictive classification and pattern recognition of pipeline datasets. The predictive system is based on a highly sparse predictive Deviant Learning Algorithm (p-DLA) designed to synthesize a sequence of memory predictive clusters for eventual monitoring, control and decision making. The DLA (p-DLA) is compared with a popular machine learning algorithm, the Long Short-Term Memory (LSTM) which is based on a temporal version of the standard feed-forward back-propagation trained artificial neural networks (ANNs). The results of simulations study show impressive results and validates the sparse memory predictive approach which favours the sub-synthesis of a highly compressed and low dimensional knowledge discovery and information prediction scheme. It also shows that the proposed new approach is competitive with a well-known and proven AI approach such as the LSTM.
[ { "version": "v1", "created": "Sat, 31 Dec 2016 00:40:17 GMT" } ]
2017-01-03T00:00:00
[ [ "Osegi", "E. N.", "" ] ]
TITLE: p-DLA: A Predictive System Model for Onshore Oil and Gas Pipeline Dataset Classification and Monitoring - Part 1 ABSTRACT: With the rise in militant activity and rogue behaviour in oil and gas regions around the world, oil pipeline disturbances is on the increase leading to huge losses to multinational operators and the countries where such facilities exist. However, this situation can be averted if adequate predictive monitoring schemes are put in place. We propose in the first part of this paper, an artificial intelligence predictive monitoring system capable of predictive classification and pattern recognition of pipeline datasets. The predictive system is based on a highly sparse predictive Deviant Learning Algorithm (p-DLA) designed to synthesize a sequence of memory predictive clusters for eventual monitoring, control and decision making. The DLA (p-DLA) is compared with a popular machine learning algorithm, the Long Short-Term Memory (LSTM) which is based on a temporal version of the standard feed-forward back-propagation trained artificial neural networks (ANNs). The results of simulations study show impressive results and validates the sparse memory predictive approach which favours the sub-synthesis of a highly compressed and low dimensional knowledge discovery and information prediction scheme. It also shows that the proposed new approach is competitive with a well-known and proven AI approach such as the LSTM.
no_new_dataset
0.947721
1701.00077
Pietro Hiram Guzzi
Pietro Hiram Guzzi, Giuseppe Agapito, Marianna Milano, Mario Cannataro
Learning Weighted Association Rules in Human Phenotype Ontology
null
null
null
null
q-bio.QM cs.AI
http://creativecommons.org/licenses/by-nc-sa/4.0/
The Human Phenotype Ontology (HPO) is a structured repository of concepts (HPO Terms) that are associated to one or more diseases. The process of association is referred to as annotation. The relevance and the specificity of both HPO terms and annotations are evaluated by a measure defined as Information Content (IC). The analysis of annotated data is thus an important challenge for bioinformatics. There exist different approaches of analysis. From those, the use of Association Rules (AR) may provide useful knowledge, and it has been used in some applications, e.g. improving the quality of annotations. Nevertheless classical association rules algorithms do not take into account the source of annotation nor the importance yielding to the generation of candidate rules with low IC. This paper presents HPO-Miner (Human Phenotype Ontology-based Weighted Association Rules) a methodology for extracting Weighted Association Rules. HPO-Miner can extract relevant rules from a biological point of view. A case study on using of HPO-Miner on publicly available HPO annotation datasets is used to demonstrate the effectiveness of our methodology.
[ { "version": "v1", "created": "Sat, 31 Dec 2016 09:19:52 GMT" } ]
2017-01-03T00:00:00
[ [ "Guzzi", "Pietro Hiram", "" ], [ "Agapito", "Giuseppe", "" ], [ "Milano", "Marianna", "" ], [ "Cannataro", "Mario", "" ] ]
TITLE: Learning Weighted Association Rules in Human Phenotype Ontology ABSTRACT: The Human Phenotype Ontology (HPO) is a structured repository of concepts (HPO Terms) that are associated to one or more diseases. The process of association is referred to as annotation. The relevance and the specificity of both HPO terms and annotations are evaluated by a measure defined as Information Content (IC). The analysis of annotated data is thus an important challenge for bioinformatics. There exist different approaches of analysis. From those, the use of Association Rules (AR) may provide useful knowledge, and it has been used in some applications, e.g. improving the quality of annotations. Nevertheless classical association rules algorithms do not take into account the source of annotation nor the importance yielding to the generation of candidate rules with low IC. This paper presents HPO-Miner (Human Phenotype Ontology-based Weighted Association Rules) a methodology for extracting Weighted Association Rules. HPO-Miner can extract relevant rules from a biological point of view. A case study on using of HPO-Miner on publicly available HPO annotation datasets is used to demonstrate the effectiveness of our methodology.
no_new_dataset
0.950915
1701.00142
Helge Rhodin
Helge Rhodin, Christian Richardt, Dan Casas, Eldar Insafutdinov, Mohammad Shafiei, Hans-Peter Seidel, Bernt Schiele, Christian Theobalt
EgoCap: Egocentric Marker-less Motion Capture with Two Fisheye Cameras (Extended Abstract)
Short version of a SIGGRAPH Asia 2016 paper arXiv:1609.07306, presented at EPIC@ECCV16
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Marker-based and marker-less optical skeletal motion-capture methods use an outside-in arrangement of cameras placed around a scene, with viewpoints converging on the center. They often create discomfort by possibly needed marker suits, and their recording volume is severely restricted and often constrained to indoor scenes with controlled backgrounds. We therefore propose a new method for real-time, marker-less and egocentric motion capture which estimates the full-body skeleton pose from a lightweight stereo pair of fisheye cameras that are attached to a helmet or virtual-reality headset. It combines the strength of a new generative pose estimation framework for fisheye views with a ConvNet-based body-part detector trained on a new automatically annotated and augmented dataset. Our inside-in method captures full-body motion in general indoor and outdoor scenes, and also crowded scenes.
[ { "version": "v1", "created": "Sat, 31 Dec 2016 16:49:39 GMT" } ]
2017-01-03T00:00:00
[ [ "Rhodin", "Helge", "" ], [ "Richardt", "Christian", "" ], [ "Casas", "Dan", "" ], [ "Insafutdinov", "Eldar", "" ], [ "Shafiei", "Mohammad", "" ], [ "Seidel", "Hans-Peter", "" ], [ "Schiele", "Bernt", "" ], [ "Theobalt", "Christian", "" ] ]
TITLE: EgoCap: Egocentric Marker-less Motion Capture with Two Fisheye Cameras (Extended Abstract) ABSTRACT: Marker-based and marker-less optical skeletal motion-capture methods use an outside-in arrangement of cameras placed around a scene, with viewpoints converging on the center. They often create discomfort by possibly needed marker suits, and their recording volume is severely restricted and often constrained to indoor scenes with controlled backgrounds. We therefore propose a new method for real-time, marker-less and egocentric motion capture which estimates the full-body skeleton pose from a lightweight stereo pair of fisheye cameras that are attached to a helmet or virtual-reality headset. It combines the strength of a new generative pose estimation framework for fisheye views with a ConvNet-based body-part detector trained on a new automatically annotated and augmented dataset. Our inside-in method captures full-body motion in general indoor and outdoor scenes, and also crowded scenes.
new_dataset
0.814274
1701.00185
Jiaming Xu
Jiaming Xu, Bo Xu, Peng Wang, Suncong Zheng, Guanhua Tian, Jun Zhao, Bo Xu
Self-Taught Convolutional Neural Networks for Short Text Clustering
33 pages, accepted for publication in Neural Networks
null
10.1016/j.neunet.2016.12.008
null
cs.IR cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Short text clustering is a challenging problem due to its sparseness of text representation. Here we propose a flexible Self-Taught Convolutional neural network framework for Short Text Clustering (dubbed STC^2), which can flexibly and successfully incorporate more useful semantic features and learn non-biased deep text representation in an unsupervised manner. In our framework, the original raw text features are firstly embedded into compact binary codes by using one existing unsupervised dimensionality reduction methods. Then, word embeddings are explored and fed into convolutional neural networks to learn deep feature representations, meanwhile the output units are used to fit the pre-trained binary codes in the training process. Finally, we get the optimal clusters by employing K-means to cluster the learned representations. Extensive experimental results demonstrate that the proposed framework is effective, flexible and outperform several popular clustering methods when tested on three public short text datasets.
[ { "version": "v1", "created": "Sun, 1 Jan 2017 01:57:59 GMT" } ]
2017-01-03T00:00:00
[ [ "Xu", "Jiaming", "" ], [ "Xu", "Bo", "" ], [ "Wang", "Peng", "" ], [ "Zheng", "Suncong", "" ], [ "Tian", "Guanhua", "" ], [ "Zhao", "Jun", "" ], [ "Xu", "Bo", "" ] ]
TITLE: Self-Taught Convolutional Neural Networks for Short Text Clustering ABSTRACT: Short text clustering is a challenging problem due to its sparseness of text representation. Here we propose a flexible Self-Taught Convolutional neural network framework for Short Text Clustering (dubbed STC^2), which can flexibly and successfully incorporate more useful semantic features and learn non-biased deep text representation in an unsupervised manner. In our framework, the original raw text features are firstly embedded into compact binary codes by using one existing unsupervised dimensionality reduction methods. Then, word embeddings are explored and fed into convolutional neural networks to learn deep feature representations, meanwhile the output units are used to fit the pre-trained binary codes in the training process. Finally, we get the optimal clusters by employing K-means to cluster the learned representations. Extensive experimental results demonstrate that the proposed framework is effective, flexible and outperform several popular clustering methods when tested on three public short text datasets.
no_new_dataset
0.947769
1701.00199
Aidong Lu
Kodzo Wegba, Aidong Lu, Yuemeng Li, and Wencheng Wang
Interactive Movie Recommendation Through Latent Semantic Analysis and Storytelling
10 pages
null
null
null
cs.IR cs.SI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recommendation has become one of the most important components of online services for improving sale records, however visualization work for online recommendation is still very limited. This paper presents an interactive recommendation approach with the following two components. First, rating records are the most widely used data for online recommendation, but they are often processed in high-dimensional spaces that can not be easily understood or interacted with. We propose a Latent Semantic Model (LSM) that captures the statistical features of semantic concepts on 2D domains and abstracts user preferences for personal recommendation. Second, we propose an interactive recommendation approach through a storytelling mechanism for promoting the communication between the user and the recommendation system. Our approach emphasizes interactivity, explicit user input, and semantic information convey; thus it can be used by general users without any knowledge of recommendation or visualization algorithms. We validate our model with data statistics and demonstrate our approach with case studies from the MovieLens100K dataset. Our approaches of latent semantic analysis and interactive recommendation can also be extended to other network-based visualization applications, including various online recommendation systems.
[ { "version": "v1", "created": "Sun, 1 Jan 2017 04:52:37 GMT" } ]
2017-01-03T00:00:00
[ [ "Wegba", "Kodzo", "" ], [ "Lu", "Aidong", "" ], [ "Li", "Yuemeng", "" ], [ "Wang", "Wencheng", "" ] ]
TITLE: Interactive Movie Recommendation Through Latent Semantic Analysis and Storytelling ABSTRACT: Recommendation has become one of the most important components of online services for improving sale records, however visualization work for online recommendation is still very limited. This paper presents an interactive recommendation approach with the following two components. First, rating records are the most widely used data for online recommendation, but they are often processed in high-dimensional spaces that can not be easily understood or interacted with. We propose a Latent Semantic Model (LSM) that captures the statistical features of semantic concepts on 2D domains and abstracts user preferences for personal recommendation. Second, we propose an interactive recommendation approach through a storytelling mechanism for promoting the communication between the user and the recommendation system. Our approach emphasizes interactivity, explicit user input, and semantic information convey; thus it can be used by general users without any knowledge of recommendation or visualization algorithms. We validate our model with data statistics and demonstrate our approach with case studies from the MovieLens100K dataset. Our approaches of latent semantic analysis and interactive recommendation can also be extended to other network-based visualization applications, including various online recommendation systems.
no_new_dataset
0.9463
1701.00334
Mehdi Moussaid
Mehdi Moussaid and Kyanoush Seyed Yahosseini
Can simple transmission chains foster collective intelligence in binary-choice tasks?
null
PLoS ONE 11(11): e0167223 (2016)
null
null
physics.soc-ph cs.SI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In many social systems, groups of individuals can find remarkably efficient solutions to complex cognitive problems, sometimes even outperforming a single expert. The success of the group, however, crucially depends on how the judgments of the group members are aggregated to produce the collective answer. A large variety of such aggregation methods have been described in the literature, such as averaging the independent judgments, relying on the majority or setting up a group discussion. In the present work, we introduce a novel approach for aggregating judgments - the transmission chain - which has not yet been consistently evaluated in the context of collective intelligence. In a transmission chain, all group members have access to a unique collective solution and can improve it sequentially. Over repeated improvements, the collective solution that emerges reflects the judgments of every group members. We address the question of whether such a transmission chain can foster collective intelligence for binary-choice problems. In a series of numerical simulations, we explore the impact of various factors on the performance of the transmission chain, such as the group size, the model parameters, and the structure of the population. The performance of this method is compared to those of the majority rule and the confidence-weighted majority. Finally, we rely on two existing datasets of individuals performing a series of binary decisions to evaluate the expected performances of the three methods empirically. We find that the parameter space where the transmission chain has the best performance rarely appears in real datasets. We conclude that the transmission chain is best suited for other types of problems, such as those that have cumulative properties.
[ { "version": "v1", "created": "Mon, 2 Jan 2017 08:32:08 GMT" } ]
2017-01-03T00:00:00
[ [ "Moussaid", "Mehdi", "" ], [ "Yahosseini", "Kyanoush Seyed", "" ] ]
TITLE: Can simple transmission chains foster collective intelligence in binary-choice tasks? ABSTRACT: In many social systems, groups of individuals can find remarkably efficient solutions to complex cognitive problems, sometimes even outperforming a single expert. The success of the group, however, crucially depends on how the judgments of the group members are aggregated to produce the collective answer. A large variety of such aggregation methods have been described in the literature, such as averaging the independent judgments, relying on the majority or setting up a group discussion. In the present work, we introduce a novel approach for aggregating judgments - the transmission chain - which has not yet been consistently evaluated in the context of collective intelligence. In a transmission chain, all group members have access to a unique collective solution and can improve it sequentially. Over repeated improvements, the collective solution that emerges reflects the judgments of every group members. We address the question of whether such a transmission chain can foster collective intelligence for binary-choice problems. In a series of numerical simulations, we explore the impact of various factors on the performance of the transmission chain, such as the group size, the model parameters, and the structure of the population. The performance of this method is compared to those of the majority rule and the confidence-weighted majority. Finally, we rely on two existing datasets of individuals performing a series of binary decisions to evaluate the expected performances of the three methods empirically. We find that the parameter space where the transmission chain has the best performance rarely appears in real datasets. We conclude that the transmission chain is best suited for other types of problems, such as those that have cumulative properties.
no_new_dataset
0.939192
1701.00449
Hamid Tizhoosh
Morteza Babaie, H.R. Tizhoosh, Shujin Zhu, M.E. Shiri
Retrieving Similar X-Ray Images from Big Image Data Using Radon Barcodes with Single Projections
Accepted for publication in ICPRAM 2017: The International Conference on Pattern Recognition Applications and Methods, Porto, Portugal, 2017
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The idea of Radon barcodes (RBC) has been introduced recently. In this paper, we propose a content-based image retrieval approach for big datasets based on Radon barcodes. Our method (Single Projection Radon Barcode, or SP-RBC) uses only a few Radon single projections for each image as global features that can serve as a basis for weak learners. This is our most important contribution in this work, which improves the results of the RBC considerably. As a matter of fact, only one projection of an image, as short as a single SURF feature vector, can already achieve acceptable results. Nevertheless, using multiple projections in a long vector will not deliver anticipated improvements. To exploit the information inherent in each projection, our method uses the outcome of each projection separately and then applies more precise local search on the small subset of retrieved images. We have tested our method using IRMA 2009 dataset a with 14,400 x-ray images as part of imageCLEF initiative. Our approach leads to a substantial decrease in the error rate in comparison with other non-learning methods.
[ { "version": "v1", "created": "Mon, 2 Jan 2017 17:00:53 GMT" } ]
2017-01-03T00:00:00
[ [ "Babaie", "Morteza", "" ], [ "Tizhoosh", "H. R.", "" ], [ "Zhu", "Shujin", "" ], [ "Shiri", "M. E.", "" ] ]
TITLE: Retrieving Similar X-Ray Images from Big Image Data Using Radon Barcodes with Single Projections ABSTRACT: The idea of Radon barcodes (RBC) has been introduced recently. In this paper, we propose a content-based image retrieval approach for big datasets based on Radon barcodes. Our method (Single Projection Radon Barcode, or SP-RBC) uses only a few Radon single projections for each image as global features that can serve as a basis for weak learners. This is our most important contribution in this work, which improves the results of the RBC considerably. As a matter of fact, only one projection of an image, as short as a single SURF feature vector, can already achieve acceptable results. Nevertheless, using multiple projections in a long vector will not deliver anticipated improvements. To exploit the information inherent in each projection, our method uses the outcome of each projection separately and then applies more precise local search on the small subset of retrieved images. We have tested our method using IRMA 2009 dataset a with 14,400 x-ray images as part of imageCLEF initiative. Our approach leads to a substantial decrease in the error rate in comparison with other non-learning methods.
no_new_dataset
0.951323
1612.01756
Francesco Cricri
Francesco Cricri, Xingyang Ni, Mikko Honkala, Emre Aksu, Moncef Gabbouj
Video Ladder Networks
This version extends the paper accepted at the NIPS 2016 workshop on ML for Spatiotemporal Forecasting, with more details and more experimental results
null
null
null
cs.LG cs.CV stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present the Video Ladder Network (VLN) for efficiently generating future video frames. VLN is a neural encoder-decoder model augmented at all layers by both recurrent and feedforward lateral connections. At each layer, these connections form a lateral recurrent residual block, where the feedforward connection represents a skip connection and the recurrent connection represents the residual. Thanks to the recurrent connections, the decoder can exploit temporal summaries generated from all layers of the encoder. This way, the top layer is relieved from the pressure of modeling lower-level spatial and temporal details. Furthermore, we extend the basic version of VLN to incorporate ResNet-style residual blocks in the encoder and decoder, which help improving the prediction results. VLN is trained in self-supervised regime on the Moving MNIST dataset, achieving competitive results while having very simple structure and providing fast inference.
[ { "version": "v1", "created": "Tue, 6 Dec 2016 11:15:28 GMT" }, { "version": "v2", "created": "Wed, 7 Dec 2016 11:35:22 GMT" }, { "version": "v3", "created": "Fri, 30 Dec 2016 09:01:02 GMT" } ]
2017-01-02T00:00:00
[ [ "Cricri", "Francesco", "" ], [ "Ni", "Xingyang", "" ], [ "Honkala", "Mikko", "" ], [ "Aksu", "Emre", "" ], [ "Gabbouj", "Moncef", "" ] ]
TITLE: Video Ladder Networks ABSTRACT: We present the Video Ladder Network (VLN) for efficiently generating future video frames. VLN is a neural encoder-decoder model augmented at all layers by both recurrent and feedforward lateral connections. At each layer, these connections form a lateral recurrent residual block, where the feedforward connection represents a skip connection and the recurrent connection represents the residual. Thanks to the recurrent connections, the decoder can exploit temporal summaries generated from all layers of the encoder. This way, the top layer is relieved from the pressure of modeling lower-level spatial and temporal details. Furthermore, we extend the basic version of VLN to incorporate ResNet-style residual blocks in the encoder and decoder, which help improving the prediction results. VLN is trained in self-supervised regime on the Moving MNIST dataset, achieving competitive results while having very simple structure and providing fast inference.
no_new_dataset
0.948489
1612.08714
Andreas Henelius
Andreas Henelius, Kai Puolam\"aki, Henrik Bostr\"om, Panagiotis Papapetrou
Clustering with Confidence: Finding Clusters with Statistical Guarantees
30 pages, 5 figures, 5 tables. Added URL to the source code
null
null
null
stat.ML cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Clustering is a widely used unsupervised learning method for finding structure in the data. However, the resulting clusters are typically presented without any guarantees on their robustness; slightly changing the used data sample or re-running a clustering algorithm involving some stochastic component may lead to completely different clusters. There is, hence, a need for techniques that can quantify the instability of the generated clusters. In this study, we propose a technique for quantifying the instability of a clustering solution and for finding robust clusters, termed core clusters, which correspond to clusters where the co-occurrence probability of each data item within a cluster is at least $1 - \alpha$. We demonstrate how solving the core clustering problem is linked to finding the largest maximal cliques in a graph. We show that the method can be used with both clustering and classification algorithms. The proposed method is tested on both simulated and real datasets. The results show that the obtained clusters indeed meet the guarantees on robustness.
[ { "version": "v1", "created": "Tue, 27 Dec 2016 19:39:23 GMT" }, { "version": "v2", "created": "Fri, 30 Dec 2016 17:56:48 GMT" } ]
2017-01-02T00:00:00
[ [ "Henelius", "Andreas", "" ], [ "Puolamäki", "Kai", "" ], [ "Boström", "Henrik", "" ], [ "Papapetrou", "Panagiotis", "" ] ]
TITLE: Clustering with Confidence: Finding Clusters with Statistical Guarantees ABSTRACT: Clustering is a widely used unsupervised learning method for finding structure in the data. However, the resulting clusters are typically presented without any guarantees on their robustness; slightly changing the used data sample or re-running a clustering algorithm involving some stochastic component may lead to completely different clusters. There is, hence, a need for techniques that can quantify the instability of the generated clusters. In this study, we propose a technique for quantifying the instability of a clustering solution and for finding robust clusters, termed core clusters, which correspond to clusters where the co-occurrence probability of each data item within a cluster is at least $1 - \alpha$. We demonstrate how solving the core clustering problem is linked to finding the largest maximal cliques in a graph. We show that the method can be used with both clustering and classification algorithms. The proposed method is tested on both simulated and real datasets. The results show that the obtained clusters indeed meet the guarantees on robustness.
no_new_dataset
0.953319
1612.09368
Dongxiao Yu
Na Wang, Dongxiao Yu, Hai Jin, Chen Qian, Xia Xie, Qiang-Sheng Hua
Parallel Algorithms for Core Maintenance in Dynamic Graphs
11 pages,9 figures,1 table
null
null
null
cs.DS
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper initiates the studies of parallel algorithms for core maintenance in dynamic graphs. The core number is a fundamental index reflecting the cohesiveness of a graph, which are widely used in large-scale graph analytics. The core maintenance problem requires to update the core numbers of vertices after a set of edges and vertices are inserted into or deleted from the graph. We investigate the parallelism in the core update process when multiple edges and vertices are inserted or deleted. Specifically, we discover a structure called superior edge set, the insertion or deletion of edges in which can be processed in parallel. Based on the structure of superior edge set, efficient parallel algorithms are then devised for incremental and decremental core maintenance respectively. To the best of our knowledge, the proposed algorithms are the first parallel ones for the fundamental core maintenance problem. The algorithms show a significant speedup in the processing time compared with previous results that sequentially handle edge and vertex insertions/deletions. Finally, extensive experiments are conducted on different types of real-world and synthetic datasets, and the results illustrate the efficiency, stability and scalability of the proposed algorithms.
[ { "version": "v1", "created": "Fri, 30 Dec 2016 02:01:33 GMT" } ]
2017-01-02T00:00:00
[ [ "Wang", "Na", "" ], [ "Yu", "Dongxiao", "" ], [ "Jin", "Hai", "" ], [ "Qian", "Chen", "" ], [ "Xie", "Xia", "" ], [ "Hua", "Qiang-Sheng", "" ] ]
TITLE: Parallel Algorithms for Core Maintenance in Dynamic Graphs ABSTRACT: This paper initiates the studies of parallel algorithms for core maintenance in dynamic graphs. The core number is a fundamental index reflecting the cohesiveness of a graph, which are widely used in large-scale graph analytics. The core maintenance problem requires to update the core numbers of vertices after a set of edges and vertices are inserted into or deleted from the graph. We investigate the parallelism in the core update process when multiple edges and vertices are inserted or deleted. Specifically, we discover a structure called superior edge set, the insertion or deletion of edges in which can be processed in parallel. Based on the structure of superior edge set, efficient parallel algorithms are then devised for incremental and decremental core maintenance respectively. To the best of our knowledge, the proposed algorithms are the first parallel ones for the fundamental core maintenance problem. The algorithms show a significant speedup in the processing time compared with previous results that sequentially handle edge and vertex insertions/deletions. Finally, extensive experiments are conducted on different types of real-world and synthetic datasets, and the results illustrate the efficiency, stability and scalability of the proposed algorithms.
no_new_dataset
0.948155
1612.09401
Pichao Wang
Pichao Wang and Wanqing Li and Chuankun Li and Yonghong Hou
Action Recognition Based on Joint Trajectory Maps with Convolutional Neural Networks
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Convolutional Neural Networks (ConvNets) have recently shown promising performance in many computer vision tasks, especially image-based recognition. How to effectively apply ConvNets to sequence-based data is still an open problem. This paper proposes an effective yet simple method to represent spatio-temporal information carried in $3D$ skeleton sequences into three $2D$ images by encoding the joint trajectories and their dynamics into color distribution in the images, referred to as Joint Trajectory Maps (JTM), and adopts ConvNets to learn the discriminative features for human action recognition. Such an image-based representation enables us to fine-tune existing ConvNets models for the classification of skeleton sequences without training the networks afresh. The three JTMs are generated in three orthogonal planes and provide complimentary information to each other. The final recognition is further improved through multiply score fusion of the three JTMs. The proposed method was evaluated on four public benchmark datasets, the large NTU RGB+D Dataset, MSRC-12 Kinect Gesture Dataset (MSRC-12), G3D Dataset and UTD Multimodal Human Action Dataset (UTD-MHAD) and achieved the state-of-the-art results.
[ { "version": "v1", "created": "Fri, 30 Dec 2016 06:32:38 GMT" } ]
2017-01-02T00:00:00
[ [ "Wang", "Pichao", "" ], [ "Li", "Wanqing", "" ], [ "Li", "Chuankun", "" ], [ "Hou", "Yonghong", "" ] ]
TITLE: Action Recognition Based on Joint Trajectory Maps with Convolutional Neural Networks ABSTRACT: Convolutional Neural Networks (ConvNets) have recently shown promising performance in many computer vision tasks, especially image-based recognition. How to effectively apply ConvNets to sequence-based data is still an open problem. This paper proposes an effective yet simple method to represent spatio-temporal information carried in $3D$ skeleton sequences into three $2D$ images by encoding the joint trajectories and their dynamics into color distribution in the images, referred to as Joint Trajectory Maps (JTM), and adopts ConvNets to learn the discriminative features for human action recognition. Such an image-based representation enables us to fine-tune existing ConvNets models for the classification of skeleton sequences without training the networks afresh. The three JTMs are generated in three orthogonal planes and provide complimentary information to each other. The final recognition is further improved through multiply score fusion of the three JTMs. The proposed method was evaluated on four public benchmark datasets, the large NTU RGB+D Dataset, MSRC-12 Kinect Gesture Dataset (MSRC-12), G3D Dataset and UTD Multimodal Human Action Dataset (UTD-MHAD) and achieved the state-of-the-art results.
no_new_dataset
0.948442
1612.06083
Yannis Papanikolaou
Yannis Papanikolaou, Ioannis Katakis, Grigorios Tsoumakas
Hierarchical Partitioning of the Output Space in Multi-label Data
null
null
null
null
stat.ML cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Hierarchy Of Multi-label classifiers (HOMER) is a multi-label learning algorithm that breaks the initial learning task to several, easier sub-tasks by first constructing a hierarchy of labels from a given label set and secondly employing a given base multi-label classifier (MLC) to the resulting sub-problems. The primary goal is to effectively address class imbalance and scalability issues that often arise in real-world multi-label classification problems. In this work, we present the general setup for a HOMER model and a simple extension of the algorithm that is suited for MLCs that output rankings. Furthermore, we provide a detailed analysis of the properties of the algorithm, both from an aspect of effectiveness and computational complexity. A secondary contribution involves the presentation of a balanced variant of the k means algorithm, which serves in the first step of the label hierarchy construction. We conduct extensive experiments on six real-world datasets, studying empirically HOMER's parameters and providing examples of instantiations of the algorithm with different clustering approaches and MLCs, The empirical results demonstrate a significant improvement over the given base MLC.
[ { "version": "v1", "created": "Mon, 19 Dec 2016 09:08:59 GMT" } ]
2016-12-31T00:00:00
[ [ "Papanikolaou", "Yannis", "" ], [ "Katakis", "Ioannis", "" ], [ "Tsoumakas", "Grigorios", "" ] ]
TITLE: Hierarchical Partitioning of the Output Space in Multi-label Data ABSTRACT: Hierarchy Of Multi-label classifiers (HOMER) is a multi-label learning algorithm that breaks the initial learning task to several, easier sub-tasks by first constructing a hierarchy of labels from a given label set and secondly employing a given base multi-label classifier (MLC) to the resulting sub-problems. The primary goal is to effectively address class imbalance and scalability issues that often arise in real-world multi-label classification problems. In this work, we present the general setup for a HOMER model and a simple extension of the algorithm that is suited for MLCs that output rankings. Furthermore, we provide a detailed analysis of the properties of the algorithm, both from an aspect of effectiveness and computational complexity. A secondary contribution involves the presentation of a balanced variant of the k means algorithm, which serves in the first step of the label hierarchy construction. We conduct extensive experiments on six real-world datasets, studying empirically HOMER's parameters and providing examples of instantiations of the algorithm with different clustering approaches and MLCs, The empirical results demonstrate a significant improvement over the given base MLC.
no_new_dataset
0.947235
1411.3406
Thomas Goldstein
Tom Goldstein, Christoph Studer, Richard Baraniuk
A Field Guide to Forward-Backward Splitting with a FASTA Implementation
null
null
null
null
cs.NA
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Non-differentiable and constrained optimization play a key role in machine learning, signal and image processing, communications, and beyond. For high-dimensional minimization problems involving large datasets or many unknowns, the forward-backward splitting method provides a simple, practical solver. Despite its apparently simplicity, the performance of the forward-backward splitting is highly sensitive to implementation details. This article is an introductory review of forward-backward splitting with a special emphasis on practical implementation concerns. Issues like stepsize selection, acceleration, stopping conditions, and initialization are considered. Numerical experiments are used to compare the effectiveness of different approaches. Many variations of forward-backward splitting are implemented in the solver FASTA (short for Fast Adaptive Shrinkage/Thresholding Algorithm). FASTA provides a simple interface for applying forward-backward splitting to a broad range of problems.
[ { "version": "v1", "created": "Thu, 13 Nov 2014 00:38:52 GMT" }, { "version": "v2", "created": "Sun, 16 Nov 2014 22:34:37 GMT" }, { "version": "v3", "created": "Fri, 9 Jan 2015 02:56:53 GMT" }, { "version": "v4", "created": "Wed, 20 Jan 2016 23:52:27 GMT" }, { "version": "v5", "created": "Mon, 15 Feb 2016 23:24:09 GMT" }, { "version": "v6", "created": "Wed, 28 Dec 2016 03:25:36 GMT" } ]
2016-12-30T00:00:00
[ [ "Goldstein", "Tom", "" ], [ "Studer", "Christoph", "" ], [ "Baraniuk", "Richard", "" ] ]
TITLE: A Field Guide to Forward-Backward Splitting with a FASTA Implementation ABSTRACT: Non-differentiable and constrained optimization play a key role in machine learning, signal and image processing, communications, and beyond. For high-dimensional minimization problems involving large datasets or many unknowns, the forward-backward splitting method provides a simple, practical solver. Despite its apparently simplicity, the performance of the forward-backward splitting is highly sensitive to implementation details. This article is an introductory review of forward-backward splitting with a special emphasis on practical implementation concerns. Issues like stepsize selection, acceleration, stopping conditions, and initialization are considered. Numerical experiments are used to compare the effectiveness of different approaches. Many variations of forward-backward splitting are implemented in the solver FASTA (short for Fast Adaptive Shrinkage/Thresholding Algorithm). FASTA provides a simple interface for applying forward-backward splitting to a broad range of problems.
no_new_dataset
0.943452
1512.02325
Wei Liu
Wei Liu, Dragomir Anguelov, Dumitru Erhan, Christian Szegedy, Scott Reed, Cheng-Yang Fu, Alexander C. Berg
SSD: Single Shot MultiBox Detector
ECCV 2016
null
10.1007/978-3-319-46448-0_2
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a method for detecting objects in images using a single deep neural network. Our approach, named SSD, discretizes the output space of bounding boxes into a set of default boxes over different aspect ratios and scales per feature map location. At prediction time, the network generates scores for the presence of each object category in each default box and produces adjustments to the box to better match the object shape. Additionally, the network combines predictions from multiple feature maps with different resolutions to naturally handle objects of various sizes. Our SSD model is simple relative to methods that require object proposals because it completely eliminates proposal generation and subsequent pixel or feature resampling stage and encapsulates all computation in a single network. This makes SSD easy to train and straightforward to integrate into systems that require a detection component. Experimental results on the PASCAL VOC, MS COCO, and ILSVRC datasets confirm that SSD has comparable accuracy to methods that utilize an additional object proposal step and is much faster, while providing a unified framework for both training and inference. Compared to other single stage methods, SSD has much better accuracy, even with a smaller input image size. For $300\times 300$ input, SSD achieves 72.1% mAP on VOC2007 test at 58 FPS on a Nvidia Titan X and for $500\times 500$ input, SSD achieves 75.1% mAP, outperforming a comparable state of the art Faster R-CNN model. Code is available at https://github.com/weiliu89/caffe/tree/ssd .
[ { "version": "v1", "created": "Tue, 8 Dec 2015 04:46:38 GMT" }, { "version": "v2", "created": "Wed, 30 Mar 2016 21:17:34 GMT" }, { "version": "v3", "created": "Tue, 8 Nov 2016 18:31:25 GMT" }, { "version": "v4", "created": "Wed, 30 Nov 2016 09:54:02 GMT" }, { "version": "v5", "created": "Thu, 29 Dec 2016 19:05:11 GMT" } ]
2016-12-30T00:00:00
[ [ "Liu", "Wei", "" ], [ "Anguelov", "Dragomir", "" ], [ "Erhan", "Dumitru", "" ], [ "Szegedy", "Christian", "" ], [ "Reed", "Scott", "" ], [ "Fu", "Cheng-Yang", "" ], [ "Berg", "Alexander C.", "" ] ]
TITLE: SSD: Single Shot MultiBox Detector ABSTRACT: We present a method for detecting objects in images using a single deep neural network. Our approach, named SSD, discretizes the output space of bounding boxes into a set of default boxes over different aspect ratios and scales per feature map location. At prediction time, the network generates scores for the presence of each object category in each default box and produces adjustments to the box to better match the object shape. Additionally, the network combines predictions from multiple feature maps with different resolutions to naturally handle objects of various sizes. Our SSD model is simple relative to methods that require object proposals because it completely eliminates proposal generation and subsequent pixel or feature resampling stage and encapsulates all computation in a single network. This makes SSD easy to train and straightforward to integrate into systems that require a detection component. Experimental results on the PASCAL VOC, MS COCO, and ILSVRC datasets confirm that SSD has comparable accuracy to methods that utilize an additional object proposal step and is much faster, while providing a unified framework for both training and inference. Compared to other single stage methods, SSD has much better accuracy, even with a smaller input image size. For $300\times 300$ input, SSD achieves 72.1% mAP on VOC2007 test at 58 FPS on a Nvidia Titan X and for $500\times 500$ input, SSD achieves 75.1% mAP, outperforming a comparable state of the art Faster R-CNN model. Code is available at https://github.com/weiliu89/caffe/tree/ssd .
no_new_dataset
0.949201
1601.00025
Mohamed Elhoseiny Mohamed Elhoseiny
Mohamed Elhoseiny, Ahmed Elgammal, Babak Saleh
Write a Classifier: Predicting Visual Classifiers from Unstructured Text
(TPAMI) Transactions on Pattern Analysis and Machine Intelligence 2017
null
null
null
cs.CV cs.CL cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
People typically learn through exposure to visual concepts associated with linguistic descriptions. For instance, teaching visual object categories to children is often accompanied by descriptions in text or speech. In a machine learning context, these observations motivates us to ask whether this learning process could be computationally modeled to learn visual classifiers. More specifically, the main question of this work is how to utilize purely textual description of visual classes with no training images, to learn explicit visual classifiers for them. We propose and investigate two baseline formulations, based on regression and domain transfer, that predict a linear classifier. Then, we propose a new constrained optimization formulation that combines a regression function and a knowledge transfer function with additional constraints to predict the parameters of a linear classifier. We also propose a generic kernelized models where a kernel classifier is predicted in the form defined by the representer theorem. The kernelized models allow defining and utilizing any two RKHS (Reproducing Kernel Hilbert Space) kernel functions in the visual space and text space, respectively. We finally propose a kernel function between unstructured text descriptions that builds on distributional semantics, which shows an advantage in our setting and could be useful for other applications. We applied all the studied models to predict visual classifiers on two fine-grained and challenging categorization datasets (CU Birds and Flower Datasets), and the results indicate successful predictions of our final model over several baselines that we designed.
[ { "version": "v1", "created": "Thu, 31 Dec 2015 22:23:34 GMT" }, { "version": "v2", "created": "Wed, 28 Dec 2016 02:13:59 GMT" } ]
2016-12-30T00:00:00
[ [ "Elhoseiny", "Mohamed", "" ], [ "Elgammal", "Ahmed", "" ], [ "Saleh", "Babak", "" ] ]
TITLE: Write a Classifier: Predicting Visual Classifiers from Unstructured Text ABSTRACT: People typically learn through exposure to visual concepts associated with linguistic descriptions. For instance, teaching visual object categories to children is often accompanied by descriptions in text or speech. In a machine learning context, these observations motivates us to ask whether this learning process could be computationally modeled to learn visual classifiers. More specifically, the main question of this work is how to utilize purely textual description of visual classes with no training images, to learn explicit visual classifiers for them. We propose and investigate two baseline formulations, based on regression and domain transfer, that predict a linear classifier. Then, we propose a new constrained optimization formulation that combines a regression function and a knowledge transfer function with additional constraints to predict the parameters of a linear classifier. We also propose a generic kernelized models where a kernel classifier is predicted in the form defined by the representer theorem. The kernelized models allow defining and utilizing any two RKHS (Reproducing Kernel Hilbert Space) kernel functions in the visual space and text space, respectively. We finally propose a kernel function between unstructured text descriptions that builds on distributional semantics, which shows an advantage in our setting and could be useful for other applications. We applied all the studied models to predict visual classifiers on two fine-grained and challenging categorization datasets (CU Birds and Flower Datasets), and the results indicate successful predictions of our final model over several baselines that we designed.
no_new_dataset
0.949012
1604.00758
Richard Darst
Richard K. Darst, Clara Granell, Alex Arenas, Sergio G\'omez, Jari Saram\"aki and Santo Fortunato
Detection of timescales in evolving complex systems
17 pages, 7 figures
Scientific Reports 6 (2016) 39713
10.1038/srep39713
null
physics.soc-ph cs.SI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Most complex systems are intrinsically dynamic in nature. The evolution of a dynamic complex system is typically represented as a sequence of snapshots, where each snapshot describes the configuration of the system at a particular instant of time. Then, one may directly follow how the snapshots evolve in time, or aggregate the snapshots within some time intervals to form representative "slices" of the evolution of the system configuration. This is often done with constant intervals, whose duration is based on arguments on the nature of the system and of its dynamics. A more refined approach would be to consider the rate of activity in the system to perform a separation of timescales. However, an even better alternative would be to define dynamic intervals that match the evolution of the system's configuration. To this end, we propose a method that aims at detecting evolutionary changes in the configuration of a complex system, and generates intervals accordingly. We show that evolutionary timescales can be identified by looking for peaks in the similarity between the sets of events on consecutive time intervals of data. Tests on simple toy models reveal that the technique is able to detect evolutionary timescales of time-varying data both when the evolution is smooth as well as when it changes sharply. This is further corroborated by analyses of several real datasets. Our method is scalable to extremely large datasets and is computationally efficient. This allows a quick, parameter-free detection of multiple timescales in the evolution of a complex system.
[ { "version": "v1", "created": "Mon, 4 Apr 2016 07:06:54 GMT" } ]
2016-12-30T00:00:00
[ [ "Darst", "Richard K.", "" ], [ "Granell", "Clara", "" ], [ "Arenas", "Alex", "" ], [ "Gómez", "Sergio", "" ], [ "Saramäki", "Jari", "" ], [ "Fortunato", "Santo", "" ] ]
TITLE: Detection of timescales in evolving complex systems ABSTRACT: Most complex systems are intrinsically dynamic in nature. The evolution of a dynamic complex system is typically represented as a sequence of snapshots, where each snapshot describes the configuration of the system at a particular instant of time. Then, one may directly follow how the snapshots evolve in time, or aggregate the snapshots within some time intervals to form representative "slices" of the evolution of the system configuration. This is often done with constant intervals, whose duration is based on arguments on the nature of the system and of its dynamics. A more refined approach would be to consider the rate of activity in the system to perform a separation of timescales. However, an even better alternative would be to define dynamic intervals that match the evolution of the system's configuration. To this end, we propose a method that aims at detecting evolutionary changes in the configuration of a complex system, and generates intervals accordingly. We show that evolutionary timescales can be identified by looking for peaks in the similarity between the sets of events on consecutive time intervals of data. Tests on simple toy models reveal that the technique is able to detect evolutionary timescales of time-varying data both when the evolution is smooth as well as when it changes sharply. This is further corroborated by analyses of several real datasets. Our method is scalable to extremely large datasets and is computationally efficient. This allows a quick, parameter-free detection of multiple timescales in the evolution of a complex system.
no_new_dataset
0.941815
1612.00338
Zohre Kohan
Zohreh Kohan, Hamidreza Farhidzadeh, Reza Azmi, Behrouz Gholizadeh
Hippocampus Temporal Lobe Epilepsy Detection using a Combination of Shape-based Features and Spherical Harmonics Representation
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Most of the temporal lobe epilepsy detection approaches are based on hippocampus deformation and use complicated features, resulting, detection is done with complicated features extraction and pre-processing task. In this paper, a new detection method based on shape-based features and spherical harmonics is proposed which can analysis the hippocampus shape anomaly and detection asymmetry. This method consisted of two main parts; (1) shape feature extraction, and (2) image classification. For evaluation, HFH database is used which is publicly available in this field. Nine different geometry and 256 spherical harmonic features are introduced then selected Eighteen of them that detect the asymmetry in hippocampus significantly in a randomly selected subset of the dataset. Then a support vector machine (SVM) classifier was employed to classify the remaining images of the dataset to normal and epileptic images using our selected features. On a dataset of 25 images, 12 images were used for feature extraction and the rest 13 for classification. The results show that the proposed method has accuracy, specificity and sensitivity of, respectively, 84%, 100%, and 80%. Therefore, the proposed approach shows acceptable result and is straightforward also; complicated pre-processing steps were omitted compared to other methods.
[ { "version": "v1", "created": "Thu, 1 Dec 2016 16:27:59 GMT" }, { "version": "v2", "created": "Wed, 28 Dec 2016 00:18:26 GMT" } ]
2016-12-30T00:00:00
[ [ "Kohan", "Zohreh", "" ], [ "Farhidzadeh", "Hamidreza", "" ], [ "Azmi", "Reza", "" ], [ "Gholizadeh", "Behrouz", "" ] ]
TITLE: Hippocampus Temporal Lobe Epilepsy Detection using a Combination of Shape-based Features and Spherical Harmonics Representation ABSTRACT: Most of the temporal lobe epilepsy detection approaches are based on hippocampus deformation and use complicated features, resulting, detection is done with complicated features extraction and pre-processing task. In this paper, a new detection method based on shape-based features and spherical harmonics is proposed which can analysis the hippocampus shape anomaly and detection asymmetry. This method consisted of two main parts; (1) shape feature extraction, and (2) image classification. For evaluation, HFH database is used which is publicly available in this field. Nine different geometry and 256 spherical harmonic features are introduced then selected Eighteen of them that detect the asymmetry in hippocampus significantly in a randomly selected subset of the dataset. Then a support vector machine (SVM) classifier was employed to classify the remaining images of the dataset to normal and epileptic images using our selected features. On a dataset of 25 images, 12 images were used for feature extraction and the rest 13 for classification. The results show that the proposed method has accuracy, specificity and sensitivity of, respectively, 84%, 100%, and 80%. Therefore, the proposed approach shows acceptable result and is straightforward also; complicated pre-processing steps were omitted compared to other methods.
no_new_dataset
0.950319
1612.05310
Luis Gerardo Mojica de la Vega
Luis Gerardo Mojica
Modeling Trolling in Social Media Conversations
null
null
null
null
cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Social media websites, electronic newspapers and Internet forums allow visitors to leave comments for others to read and interact. This exchange is not free from participants with malicious intentions, who troll others by positing messages that are intended to be provocative, offensive, or menacing. With the goal of facilitating the computational modeling of trolling, we propose a trolling categorization that is novel in the sense that it allows comment-based analysis from both the trolls' and the responders' perspectives, characterizing these two perspectives using four aspects, namely, the troll's intention and his intention disclosure, as well as the responder's interpretation of the troll's intention and her response strategy. Using this categorization, we annotate and release a dataset containing excerpts of Reddit conversations involving suspected trolls and their interactions with other users. Finally, we identify the difficult-to-classify cases in our corpus and suggest potential solutions for them.
[ { "version": "v1", "created": "Thu, 15 Dec 2016 23:41:13 GMT" }, { "version": "v2", "created": "Wed, 28 Dec 2016 16:36:17 GMT" } ]
2016-12-30T00:00:00
[ [ "Mojica", "Luis Gerardo", "" ] ]
TITLE: Modeling Trolling in Social Media Conversations ABSTRACT: Social media websites, electronic newspapers and Internet forums allow visitors to leave comments for others to read and interact. This exchange is not free from participants with malicious intentions, who troll others by positing messages that are intended to be provocative, offensive, or menacing. With the goal of facilitating the computational modeling of trolling, we propose a trolling categorization that is novel in the sense that it allows comment-based analysis from both the trolls' and the responders' perspectives, characterizing these two perspectives using four aspects, namely, the troll's intention and his intention disclosure, as well as the responder's interpretation of the troll's intention and her response strategy. Using this categorization, we annotate and release a dataset containing excerpts of Reddit conversations involving suspected trolls and their interactions with other users. Finally, we identify the difficult-to-classify cases in our corpus and suggest potential solutions for them.
new_dataset
0.95594
1612.07976
Kuniaki Saito Saito Kuniaki
Kuniaki Saito, Yusuke Mukuta, Yoshitaka Ushiku, Tatsuya Harada
DeMIAN: Deep Modality Invariant Adversarial Network
null
null
null
null
cs.LG stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Obtaining common representations from different modalities is important in that they are interchangeable with each other in a classification problem. For example, we can train a classifier on image features in the common representations and apply it to the testing of the text features in the representations. Existing multi-modal representation learning methods mainly aim to extract rich information from paired samples and train a classifier by the corresponding labels; however, collecting paired samples and their labels simultaneously involves high labor costs. Addressing paired modal samples without their labels and single modal data with their labels independently is much easier than addressing labeled multi-modal data. To obtain the common representations under such a situation, we propose to make the distributions over different modalities similar in the learned representations, namely modality-invariant representations. In particular, we propose a novel algorithm for modality-invariant representation learning, named Deep Modality Invariant Adversarial Network (DeMIAN), which utilizes the idea of Domain Adaptation (DA). Using the modality-invariant representations learned by DeMIAN, we achieved better classification accuracy than with the state-of-the-art methods, especially for some benchmark datasets of zero-shot learning.
[ { "version": "v1", "created": "Fri, 23 Dec 2016 14:07:01 GMT" }, { "version": "v2", "created": "Wed, 28 Dec 2016 02:29:15 GMT" } ]
2016-12-30T00:00:00
[ [ "Saito", "Kuniaki", "" ], [ "Mukuta", "Yusuke", "" ], [ "Ushiku", "Yoshitaka", "" ], [ "Harada", "Tatsuya", "" ] ]
TITLE: DeMIAN: Deep Modality Invariant Adversarial Network ABSTRACT: Obtaining common representations from different modalities is important in that they are interchangeable with each other in a classification problem. For example, we can train a classifier on image features in the common representations and apply it to the testing of the text features in the representations. Existing multi-modal representation learning methods mainly aim to extract rich information from paired samples and train a classifier by the corresponding labels; however, collecting paired samples and their labels simultaneously involves high labor costs. Addressing paired modal samples without their labels and single modal data with their labels independently is much easier than addressing labeled multi-modal data. To obtain the common representations under such a situation, we propose to make the distributions over different modalities similar in the learned representations, namely modality-invariant representations. In particular, we propose a novel algorithm for modality-invariant representation learning, named Deep Modality Invariant Adversarial Network (DeMIAN), which utilizes the idea of Domain Adaptation (DA). Using the modality-invariant representations learned by DeMIAN, we achieved better classification accuracy than with the state-of-the-art methods, especially for some benchmark datasets of zero-shot learning.
no_new_dataset
0.945349
1612.09007
Huan Song
Huan Song, Jayaraman J. Thiagarajan, Prasanna Sattigeri, Karthikeyan Natesan Ramamurthy, Andreas Spanias
A Deep Learning Approach To Multiple Kernel Fusion
null
null
null
null
stat.ML cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Kernel fusion is a popular and effective approach for combining multiple features that characterize different aspects of data. Traditional approaches for Multiple Kernel Learning (MKL) attempt to learn the parameters for combining the kernels through sophisticated optimization procedures. In this paper, we propose an alternative approach that creates dense embeddings for data using the kernel similarities and adopts a deep neural network architecture for fusing the embeddings. In order to improve the effectiveness of this network, we introduce the kernel dropout regularization strategy coupled with the use of an expanded set of composition kernels. Experiment results on a real-world activity recognition dataset show that the proposed architecture is effective in fusing kernels and achieves state-of-the-art performance.
[ { "version": "v1", "created": "Wed, 28 Dec 2016 23:43:27 GMT" } ]
2016-12-30T00:00:00
[ [ "Song", "Huan", "" ], [ "Thiagarajan", "Jayaraman J.", "" ], [ "Sattigeri", "Prasanna", "" ], [ "Ramamurthy", "Karthikeyan Natesan", "" ], [ "Spanias", "Andreas", "" ] ]
TITLE: A Deep Learning Approach To Multiple Kernel Fusion ABSTRACT: Kernel fusion is a popular and effective approach for combining multiple features that characterize different aspects of data. Traditional approaches for Multiple Kernel Learning (MKL) attempt to learn the parameters for combining the kernels through sophisticated optimization procedures. In this paper, we propose an alternative approach that creates dense embeddings for data using the kernel similarities and adopts a deep neural network architecture for fusing the embeddings. In order to improve the effectiveness of this network, we introduce the kernel dropout regularization strategy coupled with the use of an expanded set of composition kernels. Experiment results on a real-world activity recognition dataset show that the proposed architecture is effective in fusing kernels and achieves state-of-the-art performance.
no_new_dataset
0.950732
1612.09155
Xiaoyang Chen
Xiaoyang Chen, Hongwei Huo, Jun Huan and Jeffrey Scott Vitter
MSQ-Index: A Succinct Index for Fast Graph Similarity Search
prepare to submit
null
null
null
cs.DB
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Graph similarity search has received considerable attention in many applications, such as bioinformatics, data mining, pattern recognition, and social networks. Existing methods for this problem have limited scalability because of the huge amount of memory they consume when handling very large graph databases with millions or billions of graphs. In this paper, we study the problem of graph similarity search under the graph edit distance constraint. We present a space-efficient index structure based upon the q-gram tree that incorporates succinct data structures and hybrid encoding to achieve improved query time performance with minimal space usage. Specifically, the space usage of our index requires only 5%-15% of the previous state-of-the-art indexing size on the tested data while at the same time achieving 2-3 times acceleration in query time with small data sets. We also boost the query performance by augmenting the global filter with range search, which allows us to perform a query in a reduced region. In addition, we propose two effective filters that combine degree structures and label structures. Extensive experiments demonstrate that our proposed approach is superior in space and competitive in filtering to the state-of-the-art approaches. To the best of our knowledge, our index is the first in-memory index for this problem that successfully scales to cope with the large dataset of 25 million chemical structure graphs from the PubChem dataset.
[ { "version": "v1", "created": "Thu, 29 Dec 2016 14:23:46 GMT" } ]
2016-12-30T00:00:00
[ [ "Chen", "Xiaoyang", "" ], [ "Huo", "Hongwei", "" ], [ "Huan", "Jun", "" ], [ "Vitter", "Jeffrey Scott", "" ] ]
TITLE: MSQ-Index: A Succinct Index for Fast Graph Similarity Search ABSTRACT: Graph similarity search has received considerable attention in many applications, such as bioinformatics, data mining, pattern recognition, and social networks. Existing methods for this problem have limited scalability because of the huge amount of memory they consume when handling very large graph databases with millions or billions of graphs. In this paper, we study the problem of graph similarity search under the graph edit distance constraint. We present a space-efficient index structure based upon the q-gram tree that incorporates succinct data structures and hybrid encoding to achieve improved query time performance with minimal space usage. Specifically, the space usage of our index requires only 5%-15% of the previous state-of-the-art indexing size on the tested data while at the same time achieving 2-3 times acceleration in query time with small data sets. We also boost the query performance by augmenting the global filter with range search, which allows us to perform a query in a reduced region. In addition, we propose two effective filters that combine degree structures and label structures. Extensive experiments demonstrate that our proposed approach is superior in space and competitive in filtering to the state-of-the-art approaches. To the best of our knowledge, our index is the first in-memory index for this problem that successfully scales to cope with the large dataset of 25 million chemical structure graphs from the PubChem dataset.
no_new_dataset
0.942082
1612.09283
Ping Li
Ping Li
Generalized Intersection Kernel
null
null
null
null
stat.ML cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Following the very recent line of work on the ``generalized min-max'' (GMM) kernel, this study proposes the ``generalized intersection'' (GInt) kernel and the related ``normalized generalized min-max'' (NGMM) kernel. In computer vision, the (histogram) intersection kernel has been popular, and the GInt kernel generalizes it to data which can have both negative and positive entries. Through an extensive empirical classification study on 40 datasets from the UCI repository, we are able to show that this (tuning-free) GInt kernel performs fairly well. The empirical results also demonstrate that the NGMM kernel typically outperforms the GInt kernel. Interestingly, the NGMM kernel has another interpretation --- it is the ``asymmetrically transformed'' version of the GInt kernel, based on the idea of ``asymmetric hashing''. Just like the GMM kernel, the NGMM kernel can be efficiently linearized through (e.g.,) generalized consistent weighted sampling (GCWS), as empirically validated in our study. Owing to the discrete nature of hashed values, it also provides a scheme for approximate near neighbor search.
[ { "version": "v1", "created": "Thu, 29 Dec 2016 20:40:52 GMT" } ]
2016-12-30T00:00:00
[ [ "Li", "Ping", "" ] ]
TITLE: Generalized Intersection Kernel ABSTRACT: Following the very recent line of work on the ``generalized min-max'' (GMM) kernel, this study proposes the ``generalized intersection'' (GInt) kernel and the related ``normalized generalized min-max'' (NGMM) kernel. In computer vision, the (histogram) intersection kernel has been popular, and the GInt kernel generalizes it to data which can have both negative and positive entries. Through an extensive empirical classification study on 40 datasets from the UCI repository, we are able to show that this (tuning-free) GInt kernel performs fairly well. The empirical results also demonstrate that the NGMM kernel typically outperforms the GInt kernel. Interestingly, the NGMM kernel has another interpretation --- it is the ``asymmetrically transformed'' version of the GInt kernel, based on the idea of ``asymmetric hashing''. Just like the GMM kernel, the NGMM kernel can be efficiently linearized through (e.g.,) generalized consistent weighted sampling (GCWS), as empirically validated in our study. Owing to the discrete nature of hashed values, it also provides a scheme for approximate near neighbor search.
no_new_dataset
0.940517
1602.04058
Maroussia Favre
M. Favre and A. Wittwer and H.R. Heinimann and V.I. Yukalov and D. Sornette
Quantum decision theory in simple risky choices
null
PLoS ONE 2016 11(12): e0168045
10.1371/journal.pone.0168045
null
physics.soc-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Quantum decision theory (QDT) is a recently developed theory of decision making based on the mathematics of Hilbert spaces, a framework known in physics for its application to quantum mechanics. This framework formalizes the concept of uncertainty and other effects that are particularly manifest in cognitive processes, which makes it well suited for the study of decision making. QDT describes a decision maker's choice as a stochastic event occurring with a probability that is the sum of an objective utility factor and a subjective attraction factor. QDT offers a prediction for the average effect of subjectivity on decision makers, the quarter law. We examine individual and aggregated (group) data, and find that the results are in good agreement with the quarter law at the level of groups. At the individual level, it appears that the quarter law could be refined in order to reflect individual characteristics. This article revisits the formalism of QDT along a concrete example and offers a practical guide to researchers who are interested in applying QDT to a dataset of binary lotteries in the domain of gains.
[ { "version": "v1", "created": "Fri, 12 Feb 2016 13:57:13 GMT" }, { "version": "v2", "created": "Sat, 24 Dec 2016 09:05:14 GMT" } ]
2016-12-28T00:00:00
[ [ "Favre", "M.", "" ], [ "Wittwer", "A.", "" ], [ "Heinimann", "H. R.", "" ], [ "Yukalov", "V. I.", "" ], [ "Sornette", "D.", "" ] ]
TITLE: Quantum decision theory in simple risky choices ABSTRACT: Quantum decision theory (QDT) is a recently developed theory of decision making based on the mathematics of Hilbert spaces, a framework known in physics for its application to quantum mechanics. This framework formalizes the concept of uncertainty and other effects that are particularly manifest in cognitive processes, which makes it well suited for the study of decision making. QDT describes a decision maker's choice as a stochastic event occurring with a probability that is the sum of an objective utility factor and a subjective attraction factor. QDT offers a prediction for the average effect of subjectivity on decision makers, the quarter law. We examine individual and aggregated (group) data, and find that the results are in good agreement with the quarter law at the level of groups. At the individual level, it appears that the quarter law could be refined in order to reflect individual characteristics. This article revisits the formalism of QDT along a concrete example and offers a practical guide to researchers who are interested in applying QDT to a dataset of binary lotteries in the domain of gains.
no_new_dataset
0.944022
1603.07120
Amir Shahroudy
Amir Shahroudy, Tian-Tsong Ng, Yihong Gong, Gang Wang
Deep Multimodal Feature Analysis for Action Recognition in RGB+D Videos
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Single modality action recognition on RGB or depth sequences has been extensively explored recently. It is generally accepted that each of these two modalities has different strengths and limitations for the task of action recognition. Therefore, analysis of the RGB+D videos can help us to better study the complementary properties of these two types of modalities and achieve higher levels of performance. In this paper, we propose a new deep autoencoder based shared-specific feature factorization network to separate input multimodal signals into a hierarchy of components. Further, based on the structure of the features, a structured sparsity learning machine is proposed which utilizes mixed norms to apply regularization within components and group selection between them for better classification performance. Our experimental results show the effectiveness of our cross-modality feature analysis framework by achieving state-of-the-art accuracy for action classification on five challenging benchmark datasets.
[ { "version": "v1", "created": "Wed, 23 Mar 2016 10:22:12 GMT" }, { "version": "v2", "created": "Mon, 26 Dec 2016 05:31:52 GMT" } ]
2016-12-28T00:00:00
[ [ "Shahroudy", "Amir", "" ], [ "Ng", "Tian-Tsong", "" ], [ "Gong", "Yihong", "" ], [ "Wang", "Gang", "" ] ]
TITLE: Deep Multimodal Feature Analysis for Action Recognition in RGB+D Videos ABSTRACT: Single modality action recognition on RGB or depth sequences has been extensively explored recently. It is generally accepted that each of these two modalities has different strengths and limitations for the task of action recognition. Therefore, analysis of the RGB+D videos can help us to better study the complementary properties of these two types of modalities and achieve higher levels of performance. In this paper, we propose a new deep autoencoder based shared-specific feature factorization network to separate input multimodal signals into a hierarchy of components. Further, based on the structure of the features, a structured sparsity learning machine is proposed which utilizes mixed norms to apply regularization within components and group selection between them for better classification performance. Our experimental results show the effectiveness of our cross-modality feature analysis framework by achieving state-of-the-art accuracy for action classification on five challenging benchmark datasets.
no_new_dataset
0.943971
1605.09507
Yoonchang Han
Yoonchang Han, Jaehun Kim, Kyogu Lee
Deep convolutional neural networks for predominant instrument recognition in polyphonic music
13 pages, 7 figures, accepted for publication in IEEE/ACM Transactions on Audio, Speech, and Language Processing on 16-Nov-2016. This is initial submission version. Fully edited version is available at http://ieeexplore.ieee.org/document/7755799/
Published in: IEEE/ACM Transactions on Audio, Speech, and Language Processing ( Volume: 25, Issue: 1, Jan. 2017 ) Page(s): 208 - 221
10.1109/TASLP.2016.2632307
null
cs.SD cs.CV cs.LG cs.NE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Identifying musical instruments in polyphonic music recordings is a challenging but important problem in the field of music information retrieval. It enables music search by instrument, helps recognize musical genres, or can make music transcription easier and more accurate. In this paper, we present a convolutional neural network framework for predominant instrument recognition in real-world polyphonic music. We train our network from fixed-length music excerpts with a single-labeled predominant instrument and estimate an arbitrary number of predominant instruments from an audio signal with a variable length. To obtain the audio-excerpt-wise result, we aggregate multiple outputs from sliding windows over the test audio. In doing so, we investigated two different aggregation methods: one takes the average for each instrument and the other takes the instrument-wise sum followed by normalization. In addition, we conducted extensive experiments on several important factors that affect the performance, including analysis window size, identification threshold, and activation functions for neural networks to find the optimal set of parameters. Using a dataset of 10k audio excerpts from 11 instruments for evaluation, we found that convolutional neural networks are more robust than conventional methods that exploit spectral features and source separation with support vector machines. Experimental results showed that the proposed convolutional network architecture obtained an F1 measure of 0.602 for micro and 0.503 for macro, respectively, achieving 19.6% and 16.4% in performance improvement compared with other state-of-the-art algorithms.
[ { "version": "v1", "created": "Tue, 31 May 2016 07:11:18 GMT" }, { "version": "v2", "created": "Fri, 18 Nov 2016 08:54:57 GMT" }, { "version": "v3", "created": "Mon, 26 Dec 2016 12:29:26 GMT" } ]
2016-12-28T00:00:00
[ [ "Han", "Yoonchang", "" ], [ "Kim", "Jaehun", "" ], [ "Lee", "Kyogu", "" ] ]
TITLE: Deep convolutional neural networks for predominant instrument recognition in polyphonic music ABSTRACT: Identifying musical instruments in polyphonic music recordings is a challenging but important problem in the field of music information retrieval. It enables music search by instrument, helps recognize musical genres, or can make music transcription easier and more accurate. In this paper, we present a convolutional neural network framework for predominant instrument recognition in real-world polyphonic music. We train our network from fixed-length music excerpts with a single-labeled predominant instrument and estimate an arbitrary number of predominant instruments from an audio signal with a variable length. To obtain the audio-excerpt-wise result, we aggregate multiple outputs from sliding windows over the test audio. In doing so, we investigated two different aggregation methods: one takes the average for each instrument and the other takes the instrument-wise sum followed by normalization. In addition, we conducted extensive experiments on several important factors that affect the performance, including analysis window size, identification threshold, and activation functions for neural networks to find the optimal set of parameters. Using a dataset of 10k audio excerpts from 11 instruments for evaluation, we found that convolutional neural networks are more robust than conventional methods that exploit spectral features and source separation with support vector machines. Experimental results showed that the proposed convolutional network architecture obtained an F1 measure of 0.602 for micro and 0.503 for macro, respectively, achieving 19.6% and 16.4% in performance improvement compared with other state-of-the-art algorithms.
no_new_dataset
0.946547
1606.07253
Liuhao Ge
Liuhao Ge, Hui Liang, Junsong Yuan, Daniel Thalmann
Robust 3D Hand Pose Estimation in Single Depth Images: from Single-View CNN to Multi-View CNNs
9 pages, 9 figures, published at Computer Vision and Pattern Recognition (CVPR) 2016
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Articulated hand pose estimation plays an important role in human-computer interaction. Despite the recent progress, the accuracy of existing methods is still not satisfactory, partially due to the difficulty of embedded high-dimensional and non-linear regression problem. Different from the existing discriminative methods that regress for the hand pose with a single depth image, we propose to first project the query depth image onto three orthogonal planes and utilize these multi-view projections to regress for 2D heat-maps which estimate the joint positions on each plane. These multi-view heat-maps are then fused to produce final 3D hand pose estimation with learned pose priors. Experiments show that the proposed method largely outperforms state-of-the-art on a challenging dataset. Moreover, a cross-dataset experiment also demonstrates the good generalization ability of the proposed method.
[ { "version": "v1", "created": "Thu, 23 Jun 2016 10:00:03 GMT" }, { "version": "v2", "created": "Sun, 4 Dec 2016 09:15:42 GMT" }, { "version": "v3", "created": "Tue, 27 Dec 2016 14:22:54 GMT" } ]
2016-12-28T00:00:00
[ [ "Ge", "Liuhao", "" ], [ "Liang", "Hui", "" ], [ "Yuan", "Junsong", "" ], [ "Thalmann", "Daniel", "" ] ]
TITLE: Robust 3D Hand Pose Estimation in Single Depth Images: from Single-View CNN to Multi-View CNNs ABSTRACT: Articulated hand pose estimation plays an important role in human-computer interaction. Despite the recent progress, the accuracy of existing methods is still not satisfactory, partially due to the difficulty of embedded high-dimensional and non-linear regression problem. Different from the existing discriminative methods that regress for the hand pose with a single depth image, we propose to first project the query depth image onto three orthogonal planes and utilize these multi-view projections to regress for 2D heat-maps which estimate the joint positions on each plane. These multi-view heat-maps are then fused to produce final 3D hand pose estimation with learned pose priors. Experiments show that the proposed method largely outperforms state-of-the-art on a challenging dataset. Moreover, a cross-dataset experiment also demonstrates the good generalization ability of the proposed method.
no_new_dataset
0.946547
1610.03670
Qi Dong
Qi Dong, Shaogang Gong, Xiatian Zhu
Multi-Task Curriculum Transfer Deep Learning of Clothing Attributes
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recognising detailed clothing characteristics (fine-grained attributes) in unconstrained images of people in-the-wild is a challenging task for computer vision, especially when there is only limited training data from the wild whilst most data available for model learning are captured in well-controlled environments using fashion models (well lit, no background clutter, frontal view, high-resolution). In this work, we develop a deep learning framework capable of model transfer learning from well-controlled shop clothing images collected from web retailers to in-the-wild images from the street. Specifically, we formulate a novel Multi-Task Curriculum Transfer (MTCT) deep learning method to explore multiple sources of different types of web annotations with multi-labelled fine-grained attributes. Our multi-task loss function is designed to extract more discriminative representations in training by jointly learning all attributes, and our curriculum strategy exploits the staged easy-to-complex transfer learning motivated by cognitive studies. We demonstrate the advantages of the MTCT model over the state-of-the-art methods on the X-Domain benchmark, a large scale clothing attribute dataset. Moreover, we show that the MTCT model has a notable advantage over contemporary models when the training data size is small.
[ { "version": "v1", "created": "Wed, 12 Oct 2016 11:17:16 GMT" }, { "version": "v2", "created": "Thu, 13 Oct 2016 12:11:55 GMT" }, { "version": "v3", "created": "Fri, 14 Oct 2016 10:32:54 GMT" }, { "version": "v4", "created": "Sun, 25 Dec 2016 23:43:22 GMT" } ]
2016-12-28T00:00:00
[ [ "Dong", "Qi", "" ], [ "Gong", "Shaogang", "" ], [ "Zhu", "Xiatian", "" ] ]
TITLE: Multi-Task Curriculum Transfer Deep Learning of Clothing Attributes ABSTRACT: Recognising detailed clothing characteristics (fine-grained attributes) in unconstrained images of people in-the-wild is a challenging task for computer vision, especially when there is only limited training data from the wild whilst most data available for model learning are captured in well-controlled environments using fashion models (well lit, no background clutter, frontal view, high-resolution). In this work, we develop a deep learning framework capable of model transfer learning from well-controlled shop clothing images collected from web retailers to in-the-wild images from the street. Specifically, we formulate a novel Multi-Task Curriculum Transfer (MTCT) deep learning method to explore multiple sources of different types of web annotations with multi-labelled fine-grained attributes. Our multi-task loss function is designed to extract more discriminative representations in training by jointly learning all attributes, and our curriculum strategy exploits the staged easy-to-complex transfer learning motivated by cognitive studies. We demonstrate the advantages of the MTCT model over the state-of-the-art methods on the X-Domain benchmark, a large scale clothing attribute dataset. Moreover, we show that the MTCT model has a notable advantage over contemporary models when the training data size is small.
no_new_dataset
0.947866
1612.06007
Ahmed Alaa
Ahmed M. Alaa and Mihaela van der Schaar
A Hidden Absorbing Semi-Markov Model for Informatively Censored Temporal Data: Learning and Inference
null
null
null
null
cs.AI stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Modeling continuous-time physiological processes that manifest a patient's evolving clinical states is a key step in approaching many problems in healthcare. In this paper, we develop the Hidden Absorbing Semi-Markov Model (HASMM): a versatile probabilistic model that is capable of capturing the modern electronic health record (EHR) data. Unlike exist- ing models, an HASMM accommodates irregularly sampled, temporally correlated, and informatively censored physiological data, and can describe non-stationary clinical state transitions. Learning an HASMM from the EHR data is achieved via a novel forward- filtering backward-sampling Monte-Carlo EM algorithm that exploits the knowledge of the end-point clinical outcomes (informative censoring) in the EHR data, and implements the E-step by sequentially sampling the patients' clinical states in the reverse-time direction while conditioning on the future states. Real-time inferences are drawn via a forward- filtering algorithm that operates on a virtually constructed discrete-time embedded Markov chain that mirrors the patient's continuous-time state trajectory. We demonstrate the di- agnostic and prognostic utility of the HASMM in a critical care prognosis setting using a real-world dataset for patients admitted to the Ronald Reagan UCLA Medical Center.
[ { "version": "v1", "created": "Sun, 18 Dec 2016 23:02:02 GMT" }, { "version": "v2", "created": "Tue, 27 Dec 2016 13:44:59 GMT" } ]
2016-12-28T00:00:00
[ [ "Alaa", "Ahmed M.", "" ], [ "van der Schaar", "Mihaela", "" ] ]
TITLE: A Hidden Absorbing Semi-Markov Model for Informatively Censored Temporal Data: Learning and Inference ABSTRACT: Modeling continuous-time physiological processes that manifest a patient's evolving clinical states is a key step in approaching many problems in healthcare. In this paper, we develop the Hidden Absorbing Semi-Markov Model (HASMM): a versatile probabilistic model that is capable of capturing the modern electronic health record (EHR) data. Unlike exist- ing models, an HASMM accommodates irregularly sampled, temporally correlated, and informatively censored physiological data, and can describe non-stationary clinical state transitions. Learning an HASMM from the EHR data is achieved via a novel forward- filtering backward-sampling Monte-Carlo EM algorithm that exploits the knowledge of the end-point clinical outcomes (informative censoring) in the EHR data, and implements the E-step by sequentially sampling the patients' clinical states in the reverse-time direction while conditioning on the future states. Real-time inferences are drawn via a forward- filtering algorithm that operates on a virtually constructed discrete-time embedded Markov chain that mirrors the patient's continuous-time state trajectory. We demonstrate the di- agnostic and prognostic utility of the HASMM in a critical care prognosis setting using a real-world dataset for patients admitted to the Ronald Reagan UCLA Medical Center.
no_new_dataset
0.951323
1612.08102
Xintao Wu
Yuemeng Li, Xintao Wu, Aidong Lu
On Spectral Analysis of Directed Signed Graphs
10 pages
null
null
null
cs.SI cs.LG physics.soc-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It has been shown that the adjacency eigenspace of a network contains key information of its underlying structure. However, there has been no study on spectral analysis of the adjacency matrices of directed signed graphs. In this paper, we derive theoretical approximations of spectral projections from such directed signed networks using matrix perturbation theory. We use the derived theoretical results to study the influences of negative intra cluster and inter cluster directed edges on node spectral projections. We then develop a spectral clustering based graph partition algorithm, SC-DSG, and conduct evaluations on both synthetic and real datasets. Both theoretical analysis and empirical evaluation demonstrate the effectiveness of the proposed algorithm.
[ { "version": "v1", "created": "Fri, 23 Dec 2016 21:20:55 GMT" } ]
2016-12-28T00:00:00
[ [ "Li", "Yuemeng", "" ], [ "Wu", "Xintao", "" ], [ "Lu", "Aidong", "" ] ]
TITLE: On Spectral Analysis of Directed Signed Graphs ABSTRACT: It has been shown that the adjacency eigenspace of a network contains key information of its underlying structure. However, there has been no study on spectral analysis of the adjacency matrices of directed signed graphs. In this paper, we derive theoretical approximations of spectral projections from such directed signed networks using matrix perturbation theory. We use the derived theoretical results to study the influences of negative intra cluster and inter cluster directed edges on node spectral projections. We then develop a spectral clustering based graph partition algorithm, SC-DSG, and conduct evaluations on both synthetic and real datasets. Both theoretical analysis and empirical evaluation demonstrate the effectiveness of the proposed algorithm.
no_new_dataset
0.944587
1612.08169
Kaihua Zhang
Kaihua Zhang and Xuejun Li and Qingshan Liu
Unsupervised Video Segmentation via Spatio-Temporally Nonlocal Appearance Learning
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Video object segmentation is challenging due to the factors like rapidly fast motion, cluttered backgrounds, arbitrary object appearance variation and shape deformation. Most existing methods only explore appearance information between two consecutive frames, which do not make full use of the usefully long-term nonlocal information that is helpful to make the learned appearance stable, and hence they tend to fail when the targets suffer from large viewpoint changes and significant non-rigid deformations. In this paper, we propose a simple yet effective approach to mine the long-term sptatio-temporally nonlocal appearance information for unsupervised video segmentation. The motivation of our algorithm comes from the spatio-temporal nonlocality of the region appearance reoccurrence in a video. Specifically, we first generate a set of superpixels to represent the foreground and background, and then update the appearance of each superpixel with its long-term sptatio-temporally nonlocal counterparts generated by the approximate nearest neighbor search method with the efficient KD-tree algorithm. Then, with the updated appearances, we formulate a spatio-temporal graphical model comprised of the superpixel label consistency potentials. Finally, we generate the segmentation by optimizing the graphical model via iteratively updating the appearance model and estimating the labels. Extensive evaluations on the SegTrack and Youtube-Objects datasets demonstrate the effectiveness of the proposed method, which performs favorably against some state-of-art methods.
[ { "version": "v1", "created": "Sat, 24 Dec 2016 12:04:31 GMT" } ]
2016-12-28T00:00:00
[ [ "Zhang", "Kaihua", "" ], [ "Li", "Xuejun", "" ], [ "Liu", "Qingshan", "" ] ]
TITLE: Unsupervised Video Segmentation via Spatio-Temporally Nonlocal Appearance Learning ABSTRACT: Video object segmentation is challenging due to the factors like rapidly fast motion, cluttered backgrounds, arbitrary object appearance variation and shape deformation. Most existing methods only explore appearance information between two consecutive frames, which do not make full use of the usefully long-term nonlocal information that is helpful to make the learned appearance stable, and hence they tend to fail when the targets suffer from large viewpoint changes and significant non-rigid deformations. In this paper, we propose a simple yet effective approach to mine the long-term sptatio-temporally nonlocal appearance information for unsupervised video segmentation. The motivation of our algorithm comes from the spatio-temporal nonlocality of the region appearance reoccurrence in a video. Specifically, we first generate a set of superpixels to represent the foreground and background, and then update the appearance of each superpixel with its long-term sptatio-temporally nonlocal counterparts generated by the approximate nearest neighbor search method with the efficient KD-tree algorithm. Then, with the updated appearances, we formulate a spatio-temporal graphical model comprised of the superpixel label consistency potentials. Finally, we generate the segmentation by optimizing the graphical model via iteratively updating the appearance model and estimating the labels. Extensive evaluations on the SegTrack and Youtube-Objects datasets demonstrate the effectiveness of the proposed method, which performs favorably against some state-of-art methods.
no_new_dataset
0.950227
1612.08242
Joseph Redmon
Joseph Redmon, Ali Farhadi
YOLO9000: Better, Faster, Stronger
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We introduce YOLO9000, a state-of-the-art, real-time object detection system that can detect over 9000 object categories. First we propose various improvements to the YOLO detection method, both novel and drawn from prior work. The improved model, YOLOv2, is state-of-the-art on standard detection tasks like PASCAL VOC and COCO. At 67 FPS, YOLOv2 gets 76.8 mAP on VOC 2007. At 40 FPS, YOLOv2 gets 78.6 mAP, outperforming state-of-the-art methods like Faster RCNN with ResNet and SSD while still running significantly faster. Finally we propose a method to jointly train on object detection and classification. Using this method we train YOLO9000 simultaneously on the COCO detection dataset and the ImageNet classification dataset. Our joint training allows YOLO9000 to predict detections for object classes that don't have labelled detection data. We validate our approach on the ImageNet detection task. YOLO9000 gets 19.7 mAP on the ImageNet detection validation set despite only having detection data for 44 of the 200 classes. On the 156 classes not in COCO, YOLO9000 gets 16.0 mAP. But YOLO can detect more than just 200 classes; it predicts detections for more than 9000 different object categories. And it still runs in real-time.
[ { "version": "v1", "created": "Sun, 25 Dec 2016 07:21:38 GMT" } ]
2016-12-28T00:00:00
[ [ "Redmon", "Joseph", "" ], [ "Farhadi", "Ali", "" ] ]
TITLE: YOLO9000: Better, Faster, Stronger ABSTRACT: We introduce YOLO9000, a state-of-the-art, real-time object detection system that can detect over 9000 object categories. First we propose various improvements to the YOLO detection method, both novel and drawn from prior work. The improved model, YOLOv2, is state-of-the-art on standard detection tasks like PASCAL VOC and COCO. At 67 FPS, YOLOv2 gets 76.8 mAP on VOC 2007. At 40 FPS, YOLOv2 gets 78.6 mAP, outperforming state-of-the-art methods like Faster RCNN with ResNet and SSD while still running significantly faster. Finally we propose a method to jointly train on object detection and classification. Using this method we train YOLO9000 simultaneously on the COCO detection dataset and the ImageNet classification dataset. Our joint training allows YOLO9000 to predict detections for object classes that don't have labelled detection data. We validate our approach on the ImageNet detection task. YOLO9000 gets 19.7 mAP on the ImageNet detection validation set despite only having detection data for 44 of the 200 classes. On the 156 classes not in COCO, YOLO9000 gets 16.0 mAP. But YOLO can detect more than just 200 classes; it predicts detections for more than 9000 different object categories. And it still runs in real-time.
no_new_dataset
0.941331