categories
string
doi
string
id
string
year
float64
venue
string
link
string
updated
string
published
string
title
string
abstract
string
authors
list
cs.LG math.OC
null
1603.06782
null
null
http://arxiv.org/pdf/1603.06782v1
2016-03-22T13:29:46Z
2016-03-22T13:29:46Z
Doubly Random Parallel Stochastic Methods for Large Scale Learning
We consider learning problems over training sets in which both, the number of training examples and the dimension of the feature vectors, are large. To solve these problems we propose the random parallel stochastic algorithm (RAPSA). We call the algorithm random parallel because it utilizes multiple processors to operate in a randomly chosen subset of blocks of the feature vector. We call the algorithm parallel stochastic because processors choose elements of the training set randomly and independently. Algorithms that are parallel in either of these dimensions exist, but RAPSA is the first attempt at a methodology that is parallel in both, the selection of blocks and the selection of elements of the training set. In RAPSA, processors utilize the randomly chosen functions to compute the stochastic gradient component associated with a randomly chosen block. The technical contribution of this paper is to show that this minimally coordinated algorithm converges to the optimal classifier when the training objective is convex. In particular, we show that: (i) When using decreasing stepsizes, RAPSA converges almost surely over the random choice of blocks and functions. (ii) When using constant stepsizes, convergence is to a neighborhood of optimality with a rate that is linear in expectation. RAPSA is numerically evaluated on the MNIST digit recognition problem.
[ "['Aryan Mokhtari' 'Alec Koppel' 'Alejandro Ribeiro']", "Aryan Mokhtari and Alec Koppel and Alejandro Ribeiro" ]
q-fin.TR cs.LG q-fin.CP
null
1603.06805
null
null
http://arxiv.org/pdf/1603.06805v2
2017-05-04T14:40:42Z
2016-03-22T14:23:42Z
Using real-time cluster configurations of streaming asynchronous features as online state descriptors in financial markets
We present a scheme for online, unsupervised state discovery and detection from streaming, multi-featured, asynchronous data in high-frequency financial markets. Online feature correlations are computed using an unbiased, lossless Fourier estimator. A high-speed maximum likelihood clustering algorithm is then used to find the feature cluster configuration which best explains the structure in the correlation matrix. We conjecture that this feature configuration is a candidate descriptor for the temporal state of the system. Using a simple cluster configuration similarity metric, we are able to enumerate the state space based on prevailing feature configurations. The proposed state representation removes the need for human-driven data pre-processing for state attribute specification, allowing a learning agent to find structure in streaming data, discern changes in the system, enumerate its perceived state space and learn suitable action-selection policies.
[ "['Dieter Hendricks']", "Dieter Hendricks" ]
cs.CL cs.AI cs.LG cs.NE
null
1603.06807
null
null
http://arxiv.org/pdf/1603.06807v2
2016-05-29T20:00:20Z
2016-03-22T14:25:16Z
Generating Factoid Questions With Recurrent Neural Networks: The 30M Factoid Question-Answer Corpus
Over the past decade, large-scale supervised learning corpora have enabled machine learning researchers to make substantial advances. However, to this date, there are no large-scale question-answer corpora available. In this paper we present the 30M Factoid Question-Answer Corpus, an enormous question answer pair corpus produced by applying a novel neural network architecture on the knowledge base Freebase to transduce facts into natural language questions. The produced question answer pairs are evaluated both by human evaluators and using automatic evaluation metrics, including well-established machine translation and sentence similarity metrics. Across all evaluation criteria the question-generation model outperforms the competing template-based baseline. Furthermore, when presented to human evaluators, the generated questions appear comparable in quality to real human-generated questions.
[ "['Iulian Vlad Serban' 'Alberto García-Durán' 'Caglar Gulcehre'\n 'Sungjin Ahn' 'Sarath Chandar' 'Aaron Courville' 'Yoshua Bengio']", "Iulian Vlad Serban, Alberto Garc\\'ia-Dur\\'an, Caglar Gulcehre, Sungjin\n Ahn, Sarath Chandar, Aaron Courville, Yoshua Bengio" ]
cs.CV cs.LG
null
1603.06829
null
null
http://arxiv.org/pdf/1603.06829v1
2016-03-22T15:26:26Z
2016-03-22T15:26:26Z
Multi-velocity neural networks for gesture recognition in videos
We present a new action recognition deep neural network which adaptively learns the best action velocities in addition to the classification. While deep neural networks have reached maturity for image understanding tasks, we are still exploring network topologies and features to handle the richer environment of video clips. Here, we tackle the problem of multiple velocities in action recognition, and provide state-of-the-art results for gesture recognition, on known and new collected datasets. We further provide the training steps for our semi-supervised network, suited to learn from huge unlabeled datasets with only a fraction of labeled examples.
[ "Otkrist Gupta, Dan Raviv and Ramesh Raskar", "['Otkrist Gupta' 'Dan Raviv' 'Ramesh Raskar']" ]
cs.NE cs.LG stat.ML
null
1603.06859
null
null
http://arxiv.org/pdf/1603.06859v1
2016-03-22T16:32:26Z
2016-03-22T16:32:26Z
Enhanced perceptrons using contrastive biclusters
Perceptrons are neuronal devices capable of fully discriminating linearly separable classes. Although straightforward to implement and train, their applicability is usually hindered by non-trivial requirements imposed by real-world classification problems. Therefore, several approaches, such as kernel perceptrons, have been conceived to counteract such difficulties. In this paper, we investigate an enhanced perceptron model based on the notion of contrastive biclusters. From this perspective, a good discriminative bicluster comprises a subset of data instances belonging to one class that show high coherence across a subset of features and high differentiation from nearest instances of the other class under the same features (referred to as its contrastive bicluster). Upon each local subspace associated with a pair of contrastive biclusters a perceptron is trained and the model with highest area under the receiver operating characteristic curve (AUC) value is selected as the final classifier. Experiments conducted on a range of data sets, including those related to a difficult biosignal classification problem, show that the proposed variant can be indeed very useful, prevailing in most of the cases upon standard and kernel perceptrons in terms of accuracy and AUC measures.
[ "['André L. V. Coelho' 'Fabrício O. de França']", "Andr\\'e L. V. Coelho and Fabr\\'icio O. de Fran\\c{c}a" ]
stat.ML cs.IT cs.LG math.IT math.OC
null
1603.06861
null
null
http://arxiv.org/pdf/1603.06861v1
2016-03-22T16:34:26Z
2016-03-22T16:34:26Z
Trading-off variance and complexity in stochastic gradient descent
Stochastic gradient descent is the method of choice for large-scale machine learning problems, by virtue of its light complexity per iteration. However, it lags behind its non-stochastic counterparts with respect to the convergence rate, due to high variance introduced by the stochastic updates. The popular Stochastic Variance-Reduced Gradient (SVRG) method mitigates this shortcoming, introducing a new update rule which requires infrequent passes over the entire input dataset to compute the full-gradient. In this work, we propose CheapSVRG, a stochastic variance-reduction optimization scheme. Our algorithm is similar to SVRG but instead of the full gradient, it uses a surrogate which can be efficiently computed on a small subset of the input data. It achieves a linear convergence rate ---up to some error level, depending on the nature of the optimization problem---and features a trade-off between the computational complexity and the convergence rate. Empirical evaluation shows that CheapSVRG performs at least competitively compared to the state of the art.
[ "['Vatsal Shah' 'Megasthenis Asteris' 'Anastasios Kyrillidis'\n 'Sujay Sanghavi']", "Vatsal Shah, Megasthenis Asteris, Anastasios Kyrillidis, Sujay\n Sanghavi" ]
cs.LG cs.AI cs.IT math.IT stat.ML
null
1603.06881
null
null
http://arxiv.org/pdf/1603.06881v1
2016-03-22T17:28:08Z
2016-03-22T17:28:08Z
Feeling the Bern: Adaptive Estimators for Bernoulli Probabilities of Pairwise Comparisons
We study methods for aggregating pairwise comparison data in order to estimate outcome probabilities for future comparisons among a collection of n items. Working within a flexible framework that imposes only a form of strong stochastic transitivity (SST), we introduce an adaptivity index defined by the indifference sets of the pairwise comparison probabilities. In addition to measuring the usual worst-case risk of an estimator, this adaptivity index also captures the extent to which the estimator adapts to instance-specific difficulty relative to an oracle estimator. We prove three main results that involve this adaptivity index and different algorithms. First, we propose a three-step estimator termed Count-Randomize-Least squares (CRL), and show that it has adaptivity index upper bounded as $\sqrt{n}$ up to logarithmic factors. We then show that that conditional on the hardness of planted clique, no computationally efficient estimator can achieve an adaptivity index smaller than $\sqrt{n}$. Second, we show that a regularized least squares estimator can achieve a poly-logarithmic adaptivity index, thereby demonstrating a $\sqrt{n}$-gap between optimal and computationally achievable adaptivity. Finally, we prove that the standard least squares estimator, which is known to be optimally adaptive in several closely related problems, fails to adapt in the context of estimating pairwise probabilities.
[ "['Nihar B. Shah' 'Sivaraman Balakrishnan' 'Martin J. Wainwright']", "Nihar B. Shah, Sivaraman Balakrishnan, Martin J. Wainwright" ]
cs.CL cs.LG cs.NE
null
1603.07044
null
null
http://arxiv.org/pdf/1603.07044v1
2016-03-23T01:52:54Z
2016-03-23T01:52:54Z
Recurrent Neural Network Encoder with Attention for Community Question Answering
We apply a general recurrent neural network (RNN) encoder framework to community question answering (cQA) tasks. Our approach does not rely on any linguistic processing, and can be applied to different languages or domains. Further improvements are observed when we extend the RNN encoders with a neural attention mechanism that encourages reasoning over entire sequences. To deal with practical issues such as data sparsity and imbalanced labels, we apply various techniques such as transfer learning and multitask learning. Our experiments on the SemEval-2016 cQA task show 10% improvement on a MAP score compared to an information retrieval-based approach, and achieve comparable performance to a strong handcrafted feature-based method.
[ "Wei-Ning Hsu, Yu Zhang and James Glass", "['Wei-Ning Hsu' 'Yu Zhang' 'James Glass']" ]
stat.ML cs.LG
null
1603.07094
null
null
http://arxiv.org/pdf/1603.07094v1
2016-03-23T09:06:19Z
2016-03-23T09:06:19Z
Predicting Glaucoma Visual Field Loss by Hierarchically Aggregating Clustering-based Predictors
This study addresses the issue of predicting the glaucomatous visual field loss from patient disease datasets. Our goal is to accurately predict the progress of the disease in individual patients. As very few measurements are available for each patient, it is difficult to produce good predictors for individuals. A recently proposed clustering-based method enhances the power of prediction using patient data with similar spatiotemporal patterns. Each patient is categorized into a cluster of patients, and a predictive model is constructed using all of the data in the class. Predictions are highly dependent on the quality of clustering, but it is difficult to identify the best clustering method. Thus, we propose a method for aggregating cluster-based predictors to obtain better prediction accuracy than from a single cluster-based prediction. Further, the method shows very high performances by hierarchically aggregating experts generated from several cluster-based methods. We use real datasets to demonstrate that our method performs significantly better than conventional clustering-based and patient-wise regression methods, because the hierarchical aggregating strategy has a mechanism whereby good predictors in a small community can thrive.
[ "Motohide Higaki, Kai Morino, Hiroshi Murata, Ryo Asaoka, and Kenji\n Yamanishi", "['Motohide Higaki' 'Kai Morino' 'Hiroshi Murata' 'Ryo Asaoka'\n 'Kenji Yamanishi']" ]
math.OC cs.DC cs.LG
null
1603.07195
null
null
http://arxiv.org/pdf/1603.07195v1
2016-03-23T14:24:39Z
2016-03-23T14:24:39Z
A Decentralized Quasi-Newton Method for Dual Formulations of Consensus Optimization
This paper considers consensus optimization problems where each node of a network has access to a different summand of an aggregate cost function. Nodes try to minimize the aggregate cost function, while they exchange information only with their neighbors. We modify the dual decomposition method to incorporate a curvature correction inspired by the Broyden-Fletcher-Goldfarb-Shanno (BFGS) quasi-Newton method. The resulting dual D-BFGS method is a fully decentralized algorithm in which nodes approximate curvature information of themselves and their neighbors through the satisfaction of a secant condition. Dual D-BFGS is of interest in consensus optimization problems that are not well conditioned, making first order decentralized methods ineffective, and in which second order information is not readily available, making decentralized second order methods infeasible. Asynchronous implementation is discussed and convergence of D-BFGS is established formally for both synchronous and asynchronous implementations. Performance advantages relative to alternative decentralized algorithms are shown numerically.
[ "Mark Eisen, Aryan Mokhtari, Alejandro Ribeiro", "['Mark Eisen' 'Aryan Mokhtari' 'Alejandro Ribeiro']" ]
cs.CV cs.LG
null
1603.07235
null
null
http://arxiv.org/pdf/1603.07235v2
2016-04-27T15:31:01Z
2016-03-23T15:29:09Z
Global-Local Face Upsampling Network
Face hallucination, which is the task of generating a high-resolution face image from a low-resolution input image, is a well-studied problem that is useful in widespread application areas. Face hallucination is particularly challenging when the input face resolution is very low (e.g., 10 x 12 pixels) and/or the image is captured in an uncontrolled setting with large pose and illumination variations. In this paper, we revisit the algorithm introduced in [1] and present a deep interpretation of this framework that achieves state-of-the-art under such challenging scenarios. In our deep network architecture the global and local constraints that define a face can be efficiently modeled and learned end-to-end using training data. Conceptually our network design can be partitioned into two sub-networks: the first one implements the holistic face reconstruction according to global constraints, and the second one enhances face-specific details and enforces local patch statistics. We optimize the deep network using a new loss function for super-resolution that combines reconstruction error with a learned face quality measure in adversarial setting, producing improved visual results. We conduct extensive experiments in both controlled and uncontrolled setups and show that our algorithm improves the state of the art both numerically and visually.
[ "Oncel Tuzel, Yuichi Taguchi, and John R. Hershey", "['Oncel Tuzel' 'Yuichi Taguchi' 'John R. Hershey']" ]
cs.NE cs.LG
null
1603.07249
null
null
http://arxiv.org/pdf/1603.07249v1
2016-03-23T15:55:20Z
2016-03-23T15:55:20Z
A Tutorial on Deep Neural Networks for Intelligent Systems
Developing Intelligent Systems involves artificial intelligence approaches including artificial neural networks. Here, we present a tutorial of Deep Neural Networks (DNNs), and some insights about the origin of the term "deep"; references to deep learning are also given. Restricted Boltzmann Machines, which are the core of DNNs, are discussed in detail. An example of a simple two-layer network, performing unsupervised learning for unlabeled data, is shown. Deep Belief Networks (DBNs), which are used to build networks with more than two layers, are also described. Moreover, examples for supervised learning with DNNs performing simple prediction and classification tasks, are presented and explained. This tutorial includes two intelligent pattern recognition applications: hand- written digits (benchmark known as MNIST) and speech recognition.
[ "Juan C. Cuevas-Tello and Manuel Valenzuela-Rendon and Juan A.\n Nolazco-Flores", "['Juan C. Cuevas-Tello' 'Manuel Valenzuela-Rendon'\n 'Juan A. Nolazco-Flores']" ]
stat.ML cs.LG cs.NE
null
1603.07285
null
null
http://arxiv.org/pdf/1603.07285v2
2018-01-11T18:54:25Z
2016-03-23T17:52:21Z
A guide to convolution arithmetic for deep learning
We introduce a guide to help deep learning practitioners understand and manipulate convolutional neural network architectures. The guide clarifies the relationship between various properties (input shape, kernel shape, zero padding, strides and output shape) of convolutional, pooling and transposed convolutional layers, as well as the relationship between convolutional and transposed convolutional layers. Relationships are derived for various cases, and are illustrated in order to make them intuitive.
[ "['Vincent Dumoulin' 'Francesco Visin']", "Vincent Dumoulin, Francesco Visin" ]
cs.LG cs.AI cs.PL stat.ML
null
1603.07292
null
null
http://arxiv.org/pdf/1603.07292v1
2016-03-23T18:30:37Z
2016-03-23T18:30:37Z
Debugging Machine Learning Tasks
Unlike traditional programs (such as operating systems or word processors) which have large amounts of code, machine learning tasks use programs with relatively small amounts of code (written in machine learning libraries), but voluminous amounts of data. Just like developers of traditional programs debug errors in their code, developers of machine learning tasks debug and fix errors in their data. However, algorithms and tools for debugging and fixing errors in data are less common, when compared to their counterparts for detecting and fixing errors in code. In this paper, we consider classification tasks where errors in training data lead to misclassifications in test points, and propose an automated method to find the root causes of such misclassifications. Our root cause analysis is based on Pearl's theory of causation, and uses Pearl's PS (Probability of Sufficiency) as a scoring metric. Our implementation, Psi, encodes the computation of PS as a probabilistic program, and uses recent work on probabilistic programs and transformations on probabilistic programs (along with gray-box models of machine learning algorithms) to efficiently compute PS. Psi is able to identify root causes of data errors in interesting data sets.
[ "Aleksandar Chakarov, Aditya Nori, Sriram Rajamani, Shayak Sen, and\n Deepak Vijaykeerthy", "['Aleksandar Chakarov' 'Aditya Nori' 'Sriram Rajamani' 'Shayak Sen'\n 'Deepak Vijaykeerthy']" ]
cs.LG cs.AI cs.CR stat.ML
null
1603.07294
null
null
http://arxiv.org/pdf/1603.07294v2
2016-06-09T00:00:10Z
2016-03-23T18:31:05Z
On the Theory and Practice of Privacy-Preserving Bayesian Data Analysis
Bayesian inference has great promise for the privacy-preserving analysis of sensitive data, as posterior sampling automatically preserves differential privacy, an algorithmic notion of data privacy, under certain conditions (Dimitrakakis et al., 2014; Wang et al., 2015). While this one posterior sample (OPS) approach elegantly provides privacy "for free," it is data inefficient in the sense of asymptotic relative efficiency (ARE). We show that a simple alternative based on the Laplace mechanism, the workhorse of differential privacy, is as asymptotically efficient as non-private posterior inference, under general assumptions. This technique also has practical advantages including efficient use of the privacy budget for MCMC. We demonstrate the practicality of our approach on a time-series analysis of sensitive military records from the Afghanistan and Iraq wars disclosed by the Wikileaks organization.
[ "James Foulds, Joseph Geumlek, Max Welling, Kamalika Chaudhuri", "['James Foulds' 'Joseph Geumlek' 'Max Welling' 'Kamalika Chaudhuri']" ]
cs.LG
null
1603.07323
null
null
http://arxiv.org/pdf/1603.07323v4
2020-03-07T00:15:33Z
2016-03-23T19:58:37Z
Learning Mixtures of Plackett-Luce Models
In this paper we address the identifiability and efficient learning problems of finite mixtures of Plackett-Luce models for rank data. We prove that for any $k\geq 2$, the mixture of $k$ Plackett-Luce models for no more than $2k-1$ alternatives is non-identifiable and this bound is tight for $k=2$. For generic identifiability, we prove that the mixture of $k$ Plackett-Luce models over $m$ alternatives is generically identifiable if $k\leq\lfloor\frac {m-2} 2\rfloor!$. We also propose an efficient generalized method of moments (GMM) algorithm to learn the mixture of two Plackett-Luce models and show that the algorithm is consistent. Our experiments show that our GMM algorithm is significantly faster than the EMM algorithm by Gormley and Murphy (2008), while achieving competitive statistical efficiency.
[ "['Zhibing Zhao' 'Peter Piech' 'Lirong Xia']", "Zhibing Zhao, Peter Piech, Lirong Xia" ]
cs.LG cs.NE stat.ML
10.3389/fnins.2016.00333
1603.07341
null
null
http://arxiv.org/abs/1603.07341v1
2016-03-23T20:13:11Z
2016-03-23T20:13:11Z
Acceleration of Deep Neural Network Training with Resistive Cross-Point Devices
In recent years, deep neural networks (DNN) have demonstrated significant business impact in large scale analysis and classification tasks such as speech recognition, visual object detection, pattern extraction, etc. Training of large DNNs, however, is universally considered as time consuming and computationally intensive task that demands datacenter-scale computational resources recruited for many days. Here we propose a concept of resistive processing unit (RPU) devices that can potentially accelerate DNN training by orders of magnitude while using much less power. The proposed RPU device can store and update the weight values locally thus minimizing data movement during training and allowing to fully exploit the locality and the parallelism of the training algorithm. We identify the RPU device and system specifications for implementation of an accelerator chip for DNN training in a realistic CMOS-compatible technology. For large DNNs with about 1 billion weights this massively parallel RPU architecture can achieve acceleration factors of 30,000X compared to state-of-the-art microprocessors while providing power efficiency of 84,000 GigaOps/s/W. Problems that currently require days of training on a datacenter-size cluster with thousands of machines can be addressed within hours on a single RPU accelerator. A system consisted of a cluster of RPU accelerators will be able to tackle Big Data problems with trillions of parameters that is impossible to address today like, for example, natural speech recognition and translation between all world languages, real-time analytics on large streams of business and scientific data, integration and analysis of multimodal sensory data flows from massive number of IoT (Internet of Things) sensors.
[ "Tayfun Gokmen, Yurii Vlasov", "['Tayfun Gokmen' 'Yurii Vlasov']" ]
cs.LG cs.AR cs.DC
null
1603.07400
null
null
http://arxiv.org/pdf/1603.07400v2
2016-06-15T01:26:31Z
2016-03-24T00:52:22Z
A Reconfigurable Low Power High Throughput Architecture for Deep Network Training
General purpose computing systems are used for a large variety of applications. Extensive supports for flexibility in these systems limit their energy efficiencies. Neural networks, including deep networks, are widely used for signal processing and pattern recognition applications. In this paper we propose a multicore architecture for deep neural network based processing. Memristor crossbars are utilized to provide low power high throughput execution of neural networks. The system has both training and recognition (evaluation of new input) capabilities. The proposed system could be used for classification, dimensionality reduction, feature extraction, and anomaly detection applications. The system level area and power benefits of the specialized architecture is compared with the NVIDIA Telsa K20 GPGPU. Our experimental evaluations show that the proposed architecture can provide up to five orders of magnitude more energy efficiency over GPGPUs for deep neural network processing.
[ "Raqibul Hasan, and Tarek Taha", "['Raqibul Hasan' 'Tarek Taha']" ]
cs.SY cs.LG math.OC
10.1109/LCSYS.2019.2913770
1603.07421
null
null
http://arxiv.org/abs/1603.07421v4
2017-09-01T08:23:07Z
2016-03-24T03:13:40Z
On the Powerball Method for Optimization
We propose a new method to accelerate the convergence of optimization algorithms. This method simply adds a power coefficient $\gamma\in[0,1)$ to the gradient during optimization. We call this the Powerball method and analyze the convergence rate for the Powerball method for strongly convex functions. While theoretically the Powerball method is guaranteed to have a linear convergence rate in the same order of the gradient method, we show that empirically it significantly outperforms the gradient descent and Newton's method, especially during the initial iterations. We demonstrate that the Powerball method provides a $10$-fold speedup of the convergence of both gradient descent and L-BFGS on multiple real datasets.
[ "Ye Yuan, Mu Li, Jun Liu, Claire J. Tomlin", "['Ye Yuan' 'Mu Li' 'Jun Liu' 'Claire J. Tomlin']" ]
cs.LG cs.NE
null
1603.07454
null
null
http://arxiv.org/pdf/1603.07454v1
2016-03-24T07:12:20Z
2016-03-24T07:12:20Z
Deep Extreme Feature Extraction: New MVA Method for Searching Particles in High Energy Physics
In this paper, we present Deep Extreme Feature Extraction (DEFE), a new ensemble MVA method for searching $\tau^{+}\tau^{-}$ channel of Higgs bosons in high energy physics. DEFE can be viewed as a deep ensemble learning scheme that trains a strongly diverse set of neural feature learners without explicitly encouraging diversity and penalizing correlations. This is achieved by adopting an implicit neural controller (not involved in feedforward compuation) that directly controls and distributes gradient flows from higher level deep prediction network. Such model-independent controller results in that every single local feature learned are used in the feature-to-output mapping stage, avoiding the blind averaging of features. DEFE makes the ensembles 'deep' in the sense that it allows deep post-process of these features that tries to learn to select and abstract the ensemble of neural feature learners. With the application of this model, a selection regions full of signal process can be obtained through the training of a miniature collision events set. In comparison of the Classic Deep Neural Network, DEFE shows a state-of-the-art performance: the error rate has decreased by about 37\%, the accuracy has broken through 90\% for the first time, along with the discovery significance has reached a standard deviation of 6.0 $\sigma$. Experimental data shows that, DEFE is able to train an ensemble of discriminative feature learners that boosts the overperformance of final prediction.
[ "Chao Ma, Tianchenghou, Bin Lan, Jinhui Xu, Zhenhua Zhang", "['Chao Ma' 'Tianchenghou' 'Bin Lan' 'Jinhui Xu' 'Zhenhua Zhang']" ]
cs.LG
10.1109/IVMSPW.2016.7528230
1603.07584
null
null
http://arxiv.org/abs/1603.07584v2
2016-11-19T08:56:13Z
2016-03-24T14:15:17Z
Source Localization on Graphs via l1 Recovery and Spectral Graph Theory
We cast the problem of source localization on graphs as the simultaneous problem of sparse recovery and diffusion kernel learning. An l1 regularization term enforces the sparsity constraint while we recover the sources of diffusion from a single snapshot of the diffusion process. The diffusion kernel is estimated by assuming the process to be as generic as the standard heat diffusion. We show with synthetic data that we can concomitantly learn the diffusion kernel and the sources, given an estimated initialization. We validate our model with cholera mortality and atmospheric tracer diffusion data, showing also that the accuracy of the solution depends on the construction of the graph from the data points.
[ "Rodrigo Pena, Xavier Bresson, Pierre Vandergheynst", "['Rodrigo Pena' 'Xavier Bresson' 'Pierre Vandergheynst']" ]
cs.IR cs.CL cs.LG cs.NE
null
1603.07646
null
null
http://arxiv.org/pdf/1603.07646v1
2016-03-24T16:39:37Z
2016-03-24T16:39:37Z
Recursive Neural Language Architecture for Tag Prediction
We consider the problem of learning distributed representations for tags from their associated content for the task of tag recommendation. Considering tagging information is usually very sparse, effective learning from content and tag association is very crucial and challenging task. Recently, various neural representation learning models such as WSABIE and its variants show promising performance, mainly due to compact feature representations learned in a semantic space. However, their capacity is limited by a linear compositional approach for representing tags as sum of equal parts and hurt their performance. In this work, we propose a neural feedback relevance model for learning tag representations with weighted feature representations. Our experiments on two widely used datasets show significant improvement for quality of recommendations over various baselines.
[ "Saurabh Kataria", "['Saurabh Kataria']" ]
cs.AI cs.LG cs.NE
null
1603.07704
null
null
http://arxiv.org/pdf/1603.07704v2
2016-08-03T14:31:17Z
2016-03-24T18:54:18Z
Probabilistic Reasoning via Deep Learning: Neural Association Models
In this paper, we propose a new deep learning approach, called neural association model (NAM), for probabilistic reasoning in artificial intelligence. We propose to use neural networks to model association between any two events in a domain. Neural networks take one event as input and compute a conditional probability of the other event to model how likely these two events are to be associated. The actual meaning of the conditional probabilities varies between applications and depends on how the models are trained. In this work, as two case studies, we have investigated two NAM structures, namely deep neural networks (DNN) and relation-modulated neural nets (RMNN), on several probabilistic reasoning tasks in AI, including recognizing textual entailment, triple classification in multi-relational knowledge bases and commonsense reasoning. Experimental results on several popular datasets derived from WordNet, FreeBase and ConceptNet have all demonstrated that both DNNs and RMNNs perform equally well and they can significantly outperform the conventional methods available for these reasoning tasks. Moreover, compared with DNNs, RMNNs are superior in knowledge transfer, where a pre-trained model can be quickly extended to an unseen relation after observing only a few training samples. To further prove the effectiveness of the proposed models, in this work, we have applied NAMs to solving challenging Winograd Schema (WS) problems. Experiments conducted on a set of WS problems prove that the proposed models have the potential for commonsense reasoning.
[ "Quan Liu, Hui Jiang, Andrew Evdokimov, Zhen-Hua Ling, Xiaodan Zhu, Si\n Wei, Yu Hu", "['Quan Liu' 'Hui Jiang' 'Andrew Evdokimov' 'Zhen-Hua Ling' 'Xiaodan Zhu'\n 'Si Wei' 'Yu Hu']" ]
cs.CV cs.LG
null
1603.07772
null
null
http://arxiv.org/pdf/1603.07772v1
2016-03-24T22:43:55Z
2016-03-24T22:43:55Z
Co-occurrence Feature Learning for Skeleton based Action Recognition using Regularized Deep LSTM Networks
Skeleton based action recognition distinguishes human actions using the trajectories of skeleton joints, which provide a very good representation for describing actions. Considering that recurrent neural networks (RNNs) with Long Short-Term Memory (LSTM) can learn feature representations and model long-term temporal dependencies automatically, we propose an end-to-end fully connected deep LSTM network for skeleton based action recognition. Inspired by the observation that the co-occurrences of the joints intrinsically characterize human actions, we take the skeleton as the input at each time slot and introduce a novel regularization scheme to learn the co-occurrence features of skeleton joints. To train the deep LSTM network effectively, we propose a new dropout algorithm which simultaneously operates on the gates, cells, and output responses of the LSTM neurons. Experimental results on three human action recognition datasets consistently demonstrate the effectiveness of the proposed model.
[ "['Wentao Zhu' 'Cuiling Lan' 'Junliang Xing' 'Wenjun Zeng' 'Yanghao Li'\n 'Li Shen' 'Xiaohui Xie']", "Wentao Zhu, Cuiling Lan, Junliang Xing, Wenjun Zeng, Yanghao Li, Li\n Shen, Xiaohui Xie" ]
cs.CV cs.AI cs.LG
null
1603.07810
null
null
http://arxiv.org/pdf/1603.07810v3
2017-04-10T15:18:21Z
2016-03-25T02:52:02Z
Conditional Similarity Networks
What makes images similar? To measure the similarity between images, they are typically embedded in a feature-vector space, in which their distance preserve the relative dissimilarity. However, when learning such similarity embeddings the simplifying assumption is commonly made that images are only compared to one unique measure of similarity. A main reason for this is that contradicting notions of similarities cannot be captured in a single space. To address this shortcoming, we propose Conditional Similarity Networks (CSNs) that learn embeddings differentiated into semantically distinct subspaces that capture the different notions of similarities. CSNs jointly learn a disentangled embedding where features for different similarities are encoded in separate dimensions as well as masks that select and reweight relevant dimensions to induce a subspace that encodes a specific similarity notion. We show that our approach learns interpretable image representations with visually relevant semantic subspaces. Further, when evaluating on triplet questions from multiple similarity notions our model even outperforms the accuracy obtained by training individual specialized networks for each notion separately.
[ "Andreas Veit, Serge Belongie, Theofanis Karaletsos", "['Andreas Veit' 'Serge Belongie' 'Theofanis Karaletsos']" ]
cs.LG cs.CR
null
1603.07828
null
null
http://arxiv.org/pdf/1603.07828v2
2016-11-21T14:20:34Z
2016-03-25T06:04:30Z
Privacy-Preserved Big Data Analysis Based on Asymmetric Imputation Kernels and Multiside Similarities
This study presents an efficient approach for incomplete data classification, where the entries of samples are missing or masked due to privacy preservation. To deal with these incomplete data, a new kernel function with asymmetric intrinsic mappings is proposed in this study. Such a new kernel uses three-side similarities for kernel matrix formation. The similarity between a testing instance and a training sample relies not only on their distance but also on the relation between the testing sample and the centroid of the class, where the training sample belongs. This reduces biased estimation compared with typical methods when only one training sample is used for kernel matrix formation. Furthermore, centroid generation does not involve any clustering algorithms. The proposed kernel is capable of performing data imputation by using class-dependent averages. This enhances Fisher Discriminant Ratios and data discriminability. Experiments on two open databases were carried out for evaluating the proposed method. The result indicated that the accuracy of the proposed method was higher than that of the baseline. These findings thereby demonstrated the effectiveness of the proposed idea.
[ "Bo-Wei Chen", "['Bo-Wei Chen']" ]
cs.CV cs.LG stat.ML
null
1603.07834
null
null
http://arxiv.org/pdf/1603.07834v1
2016-03-25T07:12:32Z
2016-03-25T07:12:32Z
An end-to-end convolutional selective autoencoder approach to Soybean Cyst Nematode eggs detection
This paper proposes a novel selective autoencoder approach within the framework of deep convolutional networks. The crux of the idea is to train a deep convolutional autoencoder to suppress undesired parts of an image frame while allowing the desired parts resulting in efficient object detection. The efficacy of the framework is demonstrated on a critical plant science problem. In the United States, approximately $1 billion is lost per annum due to a nematode infection on soybean plants. Currently, plant-pathologists rely on labor-intensive and time-consuming identification of Soybean Cyst Nematode (SCN) eggs in soil samples via manual microscopy. The proposed framework attempts to significantly expedite the process by using a series of manually labeled microscopic images for training followed by automated high-throughput egg detection. The problem is particularly difficult due to the presence of a large population of non-egg particles (disturbances) in the image frames that are very similar to SCN eggs in shape, pose and illumination. Therefore, the selective autoencoder is trained to learn unique features related to the invariant shapes and sizes of the SCN eggs without handcrafting. After that, a composite non-maximum suppression and differencing is applied at the post-processing stage.
[ "Adedotun Akintayo, Nigel Lee, Vikas Chawla, Mark Mullaney, Christopher\n Marett, Asheesh Singh, Arti Singh, Greg Tylka, Baskar Ganapathysubramaniam,\n Soumik Sarkar", "['Adedotun Akintayo' 'Nigel Lee' 'Vikas Chawla' 'Mark Mullaney'\n 'Christopher Marett' 'Asheesh Singh' 'Arti Singh' 'Greg Tylka'\n 'Baskar Ganapathysubramaniam' 'Soumik Sarkar']" ]
cs.CV cs.LG cs.NE
10.1145/1235
1603.07839
null
null
http://arxiv.org/abs/1603.07839v1
2016-03-25T08:02:41Z
2016-03-25T08:02:41Z
Early Detection of Combustion Instabilities using Deep Convolutional Selective Autoencoders on Hi-speed Flame Video
This paper proposes an end-to-end convolutional selective autoencoder approach for early detection of combustion instabilities using rapidly arriving flame image frames. The instabilities arising in combustion processes cause significant deterioration and safety issues in various human-engineered systems such as land and air based gas turbine engines. These properties are described as self-sustaining, large amplitude pressure oscillations and show varying spatial scales periodic coherent vortex structure shedding. However, such instability is extremely difficult to detect before a combustion process becomes completely unstable due to its sudden (bifurcation-type) nature. In this context, an autoencoder is trained to selectively mask stable flame and allow unstable flame image frames. In that process, the model learns to identify and extract rich descriptive and explanatory flame shape features. With such a training scheme, the selective autoencoder is shown to be able to detect subtle instability features as a combustion process makes transition from stable to unstable region. As a consequence, the deep learning tool-chain can perform as an early detection framework for combustion instabilities that will have a transformative impact on the safety and performance of modern engines.
[ "['Adedotun Akintayo' 'Kin Gwn Lore' 'Soumalya Sarkar' 'Soumik Sarkar']", "Adedotun Akintayo, Kin Gwn Lore, Soumalya Sarkar, Soumik Sarkar" ]
cs.LG cs.DC
null
1603.07846
null
null
http://arxiv.org/pdf/1603.07846v1
2016-03-25T08:46:02Z
2016-03-25T08:46:02Z
Deep Learning At Scale and At Ease
Recently, deep learning techniques have enjoyed success in various multimedia applications, such as image classification and multi-modal data analysis. Large deep learning models are developed for learning rich representations of complex data. There are two challenges to overcome before deep learning can be widely adopted in multimedia and other applications. One is usability, namely the implementation of different models and training algorithms must be done by non-experts without much effort especially when the model is large and complex. The other is scalability, that is the deep learning system must be able to provision for a huge demand of computing resources for training large models with massive datasets. To address these two challenges, in this paper, we design a distributed deep learning platform called SINGA which has an intuitive programming model based on the common layer abstraction of deep learning models. Good scalability is achieved through flexible distributed training architecture and specific optimization techniques. SINGA runs on GPUs as well as on CPUs, and we show that it outperforms many other state-of-the-art deep learning systems. Our experience with developing and training deep learning models for real-life multimedia applications in SINGA shows that the platform is both usable and scalable.
[ "['Wei Wang' 'Gang Chen' 'Haibo Chen' 'Tien Tuan Anh Dinh' 'Jinyang Gao'\n 'Beng Chin Ooi' 'Kian-Lee Tan' 'Sheng Wang']", "Wei Wang, Gang Chen, Haibo Chen, Tien Tuan Anh Dinh, Jinyang Gao, Beng\n Chin Ooi, Kian-Lee Tan and Sheng Wang" ]
cs.IR cs.LG
null
1603.07849
null
null
http://arxiv.org/pdf/1603.07849v1
2016-03-25T08:49:39Z
2016-03-25T08:49:39Z
A multinomial probabilistic model for movie genre predictions
This paper proposes a movie genre-prediction based on multinomial probability model. To the best of our knowledge, this problem has not been addressed yet in the field of recommender system. The prediction of a movie genre has many practical applications including complementing the items categories given by experts and providing a surprise effect in the recommendations given to a user. We employ mulitnomial event model to estimate a likelihood of a movie given genre and the Bayes rule to evaluate the posterior probability of a genre given a movie. Experiments with the MovieLens dataset validate our approach. We achieved 70% prediction rate using only 15% of the whole set for training.
[ "Eric Makita, Artem Lenskiy", "['Eric Makita' 'Artem Lenskiy']" ]
cs.LG cs.NE math.PR
null
1603.07866
null
null
http://arxiv.org/pdf/1603.07866v1
2016-03-25T10:27:00Z
2016-03-25T10:27:00Z
The Asymptotic Performance of Linear Echo State Neural Networks
In this article, a study of the mean-square error (MSE) performance of linear echo-state neural networks is performed, both for training and testing tasks. Considering the realistic setting of noise present at the network nodes, we derive deterministic equivalents for the aforementioned MSE in the limit where the number of input data $T$ and network size $n$ both grow large. Specializing then the network connectivity matrix to specific random settings, we further obtain simple formulas that provide new insights on the performance of such networks.
[ "Romain Couillet, Gilles Wainrib, Harry Sevi, Hafiz Tiomoko Ali", "['Romain Couillet' 'Gilles Wainrib' 'Harry Sevi' 'Hafiz Tiomoko Ali']" ]
cs.LG stat.ML
null
1603.07879
null
null
http://arxiv.org/pdf/1603.07879v1
2016-03-25T11:09:22Z
2016-03-25T11:09:22Z
Hybridization of Expectation-Maximization and K-Means Algorithms for Better Clustering Performance
The present work proposes hybridization of Expectation-Maximization (EM) and K-Means techniques as an attempt to speed-up the clustering process. Though both K-Means and EM techniques look into different areas, K-means can be viewed as an approximate way to obtain maximum likelihood estimates for the means. Along with the proposed algorithm for hybridization, the present work also experiments with the Standard EM algorithm. Six different datasets are used for the experiments of which three are synthetic datasets. Clustering fitness and Sum of Squared Errors (SSE) are computed for measuring the clustering performance. In all the experiments it is observed that the proposed algorithm for hybridization of EM and K-Means techniques is consistently taking less execution time with acceptable Clustering Fitness value and less SSE than the standard EM algorithm. It is also observed that the proposed algorithm is producing better clustering results than the Cluster package of Purdue University.
[ "['D. Raja Kishor' 'N. B. Venkateswarlu']", "D. Raja Kishor, N. B. Venkateswarlu" ]
cs.CV cs.AI cs.LG
null
1603.07886
null
null
http://arxiv.org/pdf/1603.07886v1
2016-03-25T11:47:16Z
2016-03-25T11:47:16Z
A Novel Biologically Mechanism-Based Visual Cognition Model--Automatic Extraction of Semantics, Formation of Integrated Concepts and Re-selection Features for Ambiguity
Integration between biology and information science benefits both fields. Many related models have been proposed, such as computational visual cognition models, computational motor control models, integrations of both and so on. In general, the robustness and precision of recognition is one of the key problems for object recognition models. In this paper, inspired by features of human recognition process and their biological mechanisms, a new integrated and dynamic framework is proposed to mimic the semantic extraction, concept formation and feature re-selection in human visual processing. The main contributions of the proposed model are as follows: (1) Semantic feature extraction: Local semantic features are learnt from episodic features that are extracted from raw images through a deep neural network; (2) Integrated concept formation: Concepts are formed with local semantic information and structural information learnt through network. (3) Feature re-selection: When ambiguity is detected during recognition process, distinctive features according to the difference between ambiguous candidates are re-selected for recognition. Experimental results on hand-written digits and facial shape dataset show that, compared with other methods, the new proposed model exhibits higher robustness and precision for visual recognition, especially in the condition when input samples are smantic ambiguous. Meanwhile, the introduced biological mechanisms further strengthen the interaction between neuroscience and information science.
[ "['Peijie Yin' 'Hong Qiao' 'Wei Wu' 'Lu Qi' 'YinLin Li' 'Shanlin Zhong'\n 'Bo Zhang']", "Peijie Yin, Hong Qiao, Wei Wu, Lu Qi, YinLin Li, Shanlin Zhong, Bo\n Zhang" ]
cs.NE cs.LG
null
1603.07893
null
null
http://arxiv.org/pdf/1603.07893v3
2016-08-28T09:56:23Z
2016-03-25T12:28:02Z
Investigation Into The Effectiveness Of Long Short Term Memory Networks For Stock Price Prediction
The effectiveness of long short term memory networks trained by backpropagation through time for stock price prediction is explored in this paper. A range of different architecture LSTM networks are constructed trained and tested.
[ "['Hengjian Jia']", "Hengjian Jia" ]
quant-ph cs.LG
null
1603.07980
null
null
http://arxiv.org/pdf/1603.07980v1
2016-03-25T18:36:33Z
2016-03-25T18:36:33Z
Developing Quantum Annealer Driven Data Discovery
Machine learning applications are limited by computational power. In this paper, we gain novel insights into the application of quantum annealing (QA) to machine learning (ML) through experiments in natural language processing (NLP), seizure prediction, and linear separability testing. These experiments are performed on QA simulators and early-stage commercial QA hardware and compared to an unprecedented number of traditional ML techniques. We extend QBoost, an early implementation of a binary classifier that utilizes a quantum annealer, via resampling and ensembling of predicted probabilities to produce a more robust class estimator. To determine the strengths and weaknesses of this approach, resampled QBoost (RQBoost) is tested across several datasets and compared to QBoost and traditional ML. We show and explain how QBoost in combination with a commercial QA device are unable to perfectly separate binary class data which is linearly separable via logistic regression with shrinkage. We further explore the performance of RQBoost in the space of NLP and seizure prediction and find QA-enabled ML using QBoost and RQBoost is outperformed by traditional techniques. Additionally, we provide a detailed discussion of algorithmic constraints and trade-offs imposed by the use of this QA hardware. Through these experiments, we provide unique insights into the state of quantum ML via boosting and the use of quantum annealing hardware that are valuable to institutions interested in applying QA to problems in ML and beyond.
[ "['Joseph Dulny III' 'Michael Kim']", "Joseph Dulny III and Michael Kim" ]
cs.CL cs.AI cs.LG cs.NE
null
1603.08023
null
null
http://arxiv.org/pdf/1603.08023v2
2017-01-03T18:28:32Z
2016-03-25T20:32:21Z
How NOT To Evaluate Your Dialogue System: An Empirical Study of Unsupervised Evaluation Metrics for Dialogue Response Generation
We investigate evaluation metrics for dialogue response generation systems where supervised labels, such as task completion, are not available. Recent works in response generation have adopted metrics from machine translation to compare a model's generated response to a single target response. We show that these metrics correlate very weakly with human judgements in the non-technical Twitter domain, and not at all in the technical Ubuntu domain. We provide quantitative and qualitative results highlighting specific weaknesses in existing metrics, and provide recommendations for future development of better automatic evaluation metrics for dialogue systems.
[ "['Chia-Wei Liu' 'Ryan Lowe' 'Iulian V. Serban' 'Michael Noseworthy'\n 'Laurent Charlin' 'Joelle Pineau']", "Chia-Wei Liu, Ryan Lowe, Iulian V. Serban, Michael Noseworthy, Laurent\n Charlin, Joelle Pineau" ]
cs.LG cs.CR cs.SI
null
1603.08028
null
null
http://arxiv.org/pdf/1603.08028v1
2016-03-25T20:45:32Z
2016-03-25T20:45:32Z
On the Simultaneous Preservation of Privacy and Community Structure in Anonymized Networks
We consider the problem of performing community detection on a network, while maintaining privacy, assuming that the adversary has access to an auxiliary correlated network. We ask the question "Does there exist a regime where the network cannot be deanonymized perfectly, yet the community structure could be learned?." To answer this question, we derive information theoretic converses for the perfect deanonymization problem using the Stochastic Block Model and edge sub-sampling. We also provide an almost tight achievability result for perfect deanonymization. We also evaluate the performance of percolation based deanonymization algorithm on Stochastic Block Model data-sets that satisfy the conditions of our converse. Although our converse applies to exact deanonymization, the algorithm fails drastically when the conditions of the converse are met. Additionally, we study the effect of edge sub-sampling on the community structure of a real world dataset. Results show that the dataset falls under the purview of the idea of this paper. There results suggest that it may be possible to prove stronger partial deanonymizability converses, which would enable better privacy guarantees.
[ "['Daniel Cullina' 'Kushagra Singhal' 'Negar Kiyavash' 'Prateek Mittal']", "Daniel Cullina, Kushagra Singhal, Negar Kiyavash, Prateek Mittal" ]
cs.LG cs.CV cs.NE stat.ML
null
1603.08029
null
null
http://arxiv.org/pdf/1603.08029v1
2016-03-25T20:55:40Z
2016-03-25T20:55:40Z
Resnet in Resnet: Generalizing Residual Architectures
Residual networks (ResNets) have recently achieved state-of-the-art on challenging computer vision tasks. We introduce Resnet in Resnet (RiR): a deep dual-stream architecture that generalizes ResNets and standard CNNs and is easily implemented with no computational overhead. RiR consistently improves performance over ResNets, outperforms architectures with similar amounts of augmentation on CIFAR-10, and establishes a new state-of-the-art on CIFAR-100.
[ "['Sasha Targ' 'Diogo Almeida' 'Kevin Lyman']", "Sasha Targ, Diogo Almeida, Kevin Lyman" ]
stat.ML cs.DM cs.LG
null
1603.08035
null
null
http://arxiv.org/pdf/1603.08035v2
2017-07-20T21:58:31Z
2016-03-25T21:09:54Z
On kernel methods for covariates that are rankings
Permutation-valued features arise in a variety of applications, either in a direct way when preferences are elicited over a collection of items, or an indirect way in which numerical ratings are converted to a ranking. To date, there has been relatively limited study of regression, classification, and testing problems based on permutation-valued features, as opposed to permutation-valued responses. This paper studies the use of reproducing kernel Hilbert space methods for learning from permutation-valued features. These methods embed the rankings into an implicitly defined function space, and allow for efficient estimation of regression and test functions in this richer space. Our first contribution is to characterize both the feature spaces and spectral properties associated with two kernels for rankings, the Kendall and Mallows kernels. Using tools from representation theory, we explain the limited expressive power of the Kendall kernel by characterizing its degenerate spectrum, and in sharp contrast, we prove that Mallows' kernel is universal and characteristic. We also introduce families of polynomial kernels that interpolate between the Kendall (degree one) and Mallows' (infinite degree) kernels. We show the practical effectiveness of our methods via applications to Eurobarometer survey data as well as a Movielens ratings dataset.
[ "['Horia Mania' 'Aaditya Ramdas' 'Martin J. Wainwright' 'Michael I. Jordan'\n 'Benjamin Recht']", "Horia Mania, Aaditya Ramdas, Martin J. Wainwright, Michael I. Jordan,\n Benjamin Recht" ]
cs.LG
null
1603.08037
null
null
http://arxiv.org/pdf/1603.08037v1
2016-03-25T21:22:59Z
2016-03-25T21:22:59Z
On the Detection of Mixture Distributions with applications to the Most Biased Coin Problem
This paper studies the trade-off between two different kinds of pure exploration: breadth versus depth. The most biased coin problem asks how many total coin flips are required to identify a "heavy" coin from an infinite bag containing both "heavy" coins with mean $\theta_1 \in (0,1)$, and "light" coins with mean $\theta_0 \in (0,\theta_1)$, where heavy coins are drawn from the bag with probability $\alpha \in (0,1/2)$. The key difficulty of this problem lies in distinguishing whether the two kinds of coins have very similar means, or whether heavy coins are just extremely rare. This problem has applications in crowdsourcing, anomaly detection, and radio spectrum search. Chandrasekaran et. al. (2014) recently introduced a solution to this problem but it required perfect knowledge of $\theta_0,\theta_1,\alpha$. In contrast, we derive algorithms that are adaptive to partial or absent knowledge of the problem parameters. Moreover, our techniques generalize beyond coins to more general instances of infinitely many armed bandit problems. We also prove lower bounds that show our algorithm's upper bounds are tight up to $\log$ factors, and on the way characterize the sample complexity of differentiating between a single parametric distribution and a mixture of two such distributions. As a result, these bounds have surprising implications both for solutions to the most biased coin problem and for anomaly detection when only partial information about the parameters is known.
[ "Kevin Jamieson and Daniel Haas and Ben Recht", "['Kevin Jamieson' 'Daniel Haas' 'Ben Recht']" ]
cs.CL cs.LG cs.NE
null
1603.08042
null
null
http://arxiv.org/pdf/1603.08042v2
2016-05-02T15:19:30Z
2016-03-25T21:43:28Z
On the Compression of Recurrent Neural Networks with an Application to LVCSR acoustic modeling for Embedded Speech Recognition
We study the problem of compressing recurrent neural networks (RNNs). In particular, we focus on the compression of RNN acoustic models, which are motivated by the goal of building compact and accurate speech recognition systems which can be run efficiently on mobile devices. In this work, we present a technique for general recurrent model compression that jointly compresses both recurrent and non-recurrent inter-layer weight matrices. We find that the proposed technique allows us to reduce the size of our Long Short-Term Memory (LSTM) acoustic model to a third of its original size with negligible loss in accuracy.
[ "['Rohit Prabhavalkar' 'Ouais Alsharif' 'Antoine Bruguier' 'Ian McGraw']", "Rohit Prabhavalkar, Ouais Alsharif, Antoine Bruguier, Ian McGraw" ]
cs.CL cs.LG cs.NE
null
1603.08148
null
null
http://arxiv.org/pdf/1603.08148v3
2016-08-21T20:03:39Z
2016-03-26T22:31:57Z
Pointing the Unknown Words
The problem of rare and unknown words is an important issue that can potentially influence the performance of many NLP systems, including both the traditional count-based and the deep learning models. We propose a novel way to deal with the rare and unseen words for the neural network models using attention. Our model uses two softmax layers in order to predict the next word in conditional language models: one predicts the location of a word in the source sentence, and the other predicts a word in the shortlist vocabulary. At each time-step, the decision of which softmax layer to use choose adaptively made by an MLP which is conditioned on the context.~We motivate our work from a psychological evidence that humans naturally have a tendency to point towards objects in the context or the environment when the name of an object is not known.~We observe improvements on two tasks, neural machine translation on the Europarl English to French parallel corpora and text summarization on the Gigaword dataset using our proposed model.
[ "['Caglar Gulcehre' 'Sungjin Ahn' 'Ramesh Nallapati' 'Bowen Zhou'\n 'Yoshua Bengio']", "Caglar Gulcehre, Sungjin Ahn, Ramesh Nallapati, Bowen Zhou and Yoshua\n Bengio" ]
cs.CV cs.LG
null
1603.08155
null
null
http://arxiv.org/pdf/1603.08155v1
2016-03-27T01:04:27Z
2016-03-27T01:04:27Z
Perceptual Losses for Real-Time Style Transfer and Super-Resolution
We consider image transformation problems, where an input image is transformed into an output image. Recent methods for such problems typically train feed-forward convolutional neural networks using a \emph{per-pixel} loss between the output and ground-truth images. Parallel work has shown that high-quality images can be generated by defining and optimizing \emph{perceptual} loss functions based on high-level features extracted from pretrained networks. We combine the benefits of both approaches, and propose the use of perceptual loss functions for training feed-forward networks for image transformation tasks. We show results on image style transfer, where a feed-forward network is trained to solve the optimization problem proposed by Gatys et al in real-time. Compared to the optimization-based method, our network gives similar qualitative results but is three orders of magnitude faster. We also experiment with single-image super-resolution, where replacing a per-pixel loss with a perceptual loss gives visually pleasing results.
[ "['Justin Johnson' 'Alexandre Alahi' 'Li Fei-Fei']", "Justin Johnson, Alexandre Alahi, Li Fei-Fei" ]
cs.CV cs.LG
null
1603.08212
null
null
http://arxiv.org/pdf/1603.08212v1
2016-03-27T12:45:33Z
2016-03-27T12:45:33Z
Human Pose Estimation using Deep Consensus Voting
In this paper we consider the problem of human pose estimation from a single still image. We propose a novel approach where each location in the image votes for the position of each keypoint using a convolutional neural net. The voting scheme allows us to utilize information from the whole image, rather than rely on a sparse set of keypoint locations. Using dense, multi-target votes, not only produces good keypoint predictions, but also enables us to compute image-dependent joint keypoint probabilities by looking at consensus voting. This differs from most previous methods where joint probabilities are learned from relative keypoint locations and are independent of the image. We finally combine the keypoints votes and joint probabilities in order to identify the optimal pose configuration. We show our competitive performance on the MPII Human Pose and Leeds Sports Pose datasets.
[ "['Ita Lifshitz' 'Ethan Fetaya' 'Shimon Ullman']", "Ita Lifshitz, Ethan Fetaya and Shimon Ullman" ]
cs.CV cs.LG cs.NE
null
1603.08233
null
null
http://arxiv.org/pdf/1603.08233v2
2016-06-16T21:00:53Z
2016-03-27T16:36:43Z
Evolution of active categorical image classification via saccadic eye movement
Pattern recognition and classification is a central concern for modern information processing systems. In particular, one key challenge to image and video classification has been that the computational cost of image processing scales linearly with the number of pixels in the image or video. Here we present an intelligent machine (the "active categorical classifier," or ACC) that is inspired by the saccadic movements of the eye, and is capable of classifying images by selectively scanning only a portion of the image. We harness evolutionary computation to optimize the ACC on the MNIST hand-written digit classification task, and provide a proof-of-concept that the ACC works on noisy multi-class data. We further analyze the ACC and demonstrate its ability to classify images after viewing only a fraction of the pixels, and provide insight on future research paths to further improve upon the ACC presented here.
[ "['Randal S. Olson' 'Jason H. Moore' 'Christoph Adami']", "Randal S. Olson, Jason H. Moore, Christoph Adami" ]
cs.AI cs.LG
null
1603.08253
null
null
http://arxiv.org/pdf/1603.08253v3
2018-06-17T16:42:04Z
2016-03-27T20:02:13Z
Negative Learning Rates and P-Learning
We present a method of training a differentiable function approximator for a regression task using negative examples. We effect this training using negative learning rates. We also show how this method can be used to perform direct policy learning in a reinforcement learning setting.
[ "Devon Merrill", "['Devon Merrill']" ]
cs.AI cs.LG cs.NE
null
1603.08262
null
null
http://arxiv.org/pdf/1603.08262v1
2016-03-27T22:01:59Z
2016-03-27T22:01:59Z
Towards Machine Intelligence
There exists a theory of a single general-purpose learning algorithm which could explain the principles of its operation. This theory assumes that the brain has some initial rough architecture, a small library of simple innate circuits which are prewired at birth and proposes that all significant mental algorithms can be learned. Given current understanding and observations, this paper reviews and lists the ingredients of such an algorithm from both architectural and functional perspectives.
[ "Kamil Rocki", "['Kamil Rocki']" ]
cs.LG
null
1603.08293
null
null
http://arxiv.org/pdf/1603.08293v1
2016-03-28T03:37:26Z
2016-03-28T03:37:26Z
Non-Greedy L21-Norm Maximization for Principal Component Analysis
Principal Component Analysis (PCA) is one of the most important unsupervised methods to handle high-dimensional data. However, due to the high computational complexity of its eigen decomposition solution, it hard to apply PCA to the large-scale data with high dimensionality. Meanwhile, the squared L2-norm based objective makes it sensitive to data outliers. In recent research, the L1-norm maximization based PCA method was proposed for efficient computation and being robust to outliers. However, this work used a greedy strategy to solve the eigen vectors. Moreover, the L1-norm maximization based objective may not be the correct robust PCA formulation, because it loses the theoretical connection to the minimization of data reconstruction error, which is one of the most important intuitions and goals of PCA. In this paper, we propose to maximize the L21-norm based robust PCA objective, which is theoretically connected to the minimization of reconstruction error. More importantly, we propose the efficient non-greedy optimization algorithms to solve our objective and the more general L21-norm maximization problem with theoretically guaranteed convergence. Experimental results on real world data sets show the effectiveness of the proposed method for principal component analysis.
[ "['Feiping Nie' 'Heng Huang']", "Feiping Nie and Heng Huang" ]
cs.LG cs.NE
10.14569/IJACSA.2016.070203
1603.08296
null
null
http://arxiv.org/abs/1603.08296v1
2016-03-21T20:12:44Z
2016-03-21T20:12:44Z
The SVM Classifier Based on the Modified Particle Swarm Optimization
The problem of development of the SVM classifier based on the modified particle swarm optimization has been considered. This algorithm carries out the simultaneous search of the kernel function type, values of the kernel function parameters and value of the regularization parameter for the SVM classifier. Such SVM classifier provides the high quality of data classification. The idea of particles' {\guillemotleft}regeneration{\guillemotright} is put on the basis of the modified particle swarm optimization algorithm. At the realization of this idea, some particles change their kernel function type to the one which corresponds to the particle with the best value of the classification accuracy. The offered particle swarm optimization algorithm allows reducing the time expenditures for development of the SVM classifier. The results of experimental studies confirm the efficiency of this algorithm.
[ "['L. Demidova' 'E. Nikulchev' 'Yu. Sokolova']", "L. Demidova, E. Nikulchev, Yu. Sokolova" ]
cs.LG
null
1603.08318
null
null
http://arxiv.org/pdf/1603.08318v2
2016-05-16T07:02:05Z
2016-03-28T05:58:15Z
Exclusivity Regularized Machine
It has been recognized that the diversity of base learners is of utmost importance to a good ensemble. This paper defines a novel measurement of diversity, termed as exclusivity. With the designed exclusivity, we further propose an ensemble model, namely Exclusivity Regularized Machine (ERM), to jointly suppress the training error of ensemble and enhance the diversity between bases. Moreover, an Augmented Lagrange Multiplier based algorithm is customized to effectively and efficiently seek the optimal solution of ERM. Theoretical analysis on convergence and global optimality of the proposed algorithm, as well as experiments are provided to reveal the efficacy of our method and show its superiority over state-of-the-art alternatives in terms of accuracy and efficiency.
[ "Xiaojie Guo", "['Xiaojie Guo']" ]
cs.CV cs.CL cs.LG
null
1603.08321
null
null
http://arxiv.org/pdf/1603.08321v1
2016-03-28T06:06:10Z
2016-03-28T06:06:10Z
Audio Visual Emotion Recognition with Temporal Alignment and Perception Attention
This paper focuses on two key problems for audio-visual emotion recognition in the video. One is the audio and visual streams temporal alignment for feature level fusion. The other one is locating and re-weighting the perception attentions in the whole audio-visual stream for better recognition. The Long Short Term Memory Recurrent Neural Network (LSTM-RNN) is employed as the main classification architecture. Firstly, soft attention mechanism aligns the audio and visual streams. Secondly, seven emotion embedding vectors, which are corresponding to each classification emotion type, are added to locate the perception attentions. The locating and re-weighting process is also based on the soft attention mechanism. The experiment results on EmotiW2015 dataset and the qualitative analysis show the efficiency of the proposed two techniques.
[ "['Linlin Chao' 'Jianhua Tao' 'Minghao Yang' 'Ya Li' 'Zhengqi Wen']", "Linlin Chao, Jianhua Tao, Minghao Yang, Ya Li and Zhengqi Wen" ]
cs.LG cs.CV
10.1007/978-3-319-26227-7_18
1603.08342
null
null
http://arxiv.org/abs/1603.08342v1
2016-03-28T08:54:03Z
2016-03-28T08:54:03Z
Hierarchical Gaussian Mixture Model with Objects Attached to Terminal and Non-terminal Dendrogram Nodes
A hierarchical clustering algorithm based on Gaussian mixture model is presented. The key difference to regular hierarchical mixture models is the ability to store objects in both terminal and nonterminal nodes. Upper levels of the hierarchy contain sparsely distributed objects, while lower levels contain densely represented ones. As it was shown by experiments, this ability helps in noise detection (modelling). Furthermore, compared to regular hierarchical mixture model, the presented method generates more compact dendrograms with higher quality measured by adopted F-measure.
[ "{\\L}ukasz P. Olech and Mariusz Paradowski", "['Łukasz P. Olech' 'Mariusz Paradowski']" ]
cs.CV cs.LG
null
1603.08358
null
null
http://arxiv.org/pdf/1603.08358v4
2016-11-29T14:52:20Z
2016-03-28T10:55:20Z
Fast, Exact and Multi-Scale Inference for Semantic Image Segmentation with Deep Gaussian CRFs
In this work we propose a structured prediction technique that combines the virtues of Gaussian Conditional Random Fields (G-CRF) with Deep Learning: (a) our structured prediction task has a unique global optimum that is obtained exactly from the solution of a linear system (b) the gradients of our model parameters are analytically computed using closed form expressions, in contrast to the memory-demanding contemporary deep structured prediction approaches that rely on back-propagation-through-time, (c) our pairwise terms do not have to be simple hand-crafted expressions, as in the line of works building on the DenseCRF, but can rather be `discovered' from data through deep architectures, and (d) out system can trained in an end-to-end manner. Building on standard tools from numerical analysis we develop very efficient algorithms for inference and learning, as well as a customized technique adapted to the semantic segmentation task. This efficiency allows us to explore more sophisticated architectures for structured prediction in deep learning: we introduce multi-resolution architectures to couple information across scales in a joint optimization framework, yielding systematic improvements. We demonstrate the utility of our approach on the challenging VOC PASCAL 2012 image segmentation benchmark, showing substantial improvements over strong baselines. We make all of our code and experiments available at {https://github.com/siddharthachandra/gcrf}
[ "Siddhartha Chandra and Iasonas Kokkinos", "['Siddhartha Chandra' 'Iasonas Kokkinos']" ]
cs.LG cs.CG cs.CV cs.NE
null
1603.08367
null
null
http://arxiv.org/pdf/1603.08367v1
2016-03-28T12:06:49Z
2016-03-28T12:06:49Z
Sparse Activity and Sparse Connectivity in Supervised Learning
Sparseness is a useful regularizer for learning in a wide range of applications, in particular in neural networks. This paper proposes a model targeted at classification tasks, where sparse activity and sparse connectivity are used to enhance classification capabilities. The tool for achieving this is a sparseness-enforcing projection operator which finds the closest vector with a pre-defined sparseness for any given vector. In the theoretical part of this paper, a comprehensive theory for such a projection is developed. In conclusion, it is shown that the projection is differentiable almost everywhere and can thus be implemented as a smooth neuronal transfer function. The entire model can hence be tuned end-to-end using gradient-based methods. Experiments on the MNIST database of handwritten digits show that classification performance can be boosted by sparse activity or sparse connectivity. With a combination of both, performance can be significantly better compared to classical non-sparse approaches.
[ "Markus Thom and G\\\"unther Palm", "['Markus Thom' 'Günther Palm']" ]
cs.CL cs.CV cs.LG cs.NE
null
1603.08474
null
null
http://arxiv.org/pdf/1603.08474v1
2016-03-28T18:38:46Z
2016-03-28T18:38:46Z
Deep Embedding for Spatial Role Labeling
This paper introduces the visually informed embedding of word (VIEW), a continuous vector representation for a word extracted from a deep neural model trained using the Microsoft COCO data set to forecast the spatial arrangements between visual objects, given a textual description. The model is composed of a deep multilayer perceptron (MLP) stacked on the top of a Long Short Term Memory (LSTM) network, the latter being preceded by an embedding layer. The VIEW is applied to transferring multimodal background knowledge to Spatial Role Labeling (SpRL) algorithms, which recognize spatial relations between objects mentioned in the text. This work also contributes with a new method to select complementary features and a fine-tuning method for MLP that improves the $F1$ measure in classifying the words into spatial roles. The VIEW is evaluated with the Task 3 of SemEval-2013 benchmark data set, SpaceEval.
[ "['Oswaldo Ludwig' 'Xiao Liu' 'Parisa Kordjamshidi' 'Marie-Francine Moens']", "Oswaldo Ludwig, Xiao Liu, Parisa Kordjamshidi, Marie-Francine Moens" ]
stat.ML cs.LG
null
1603.08482
null
null
http://arxiv.org/pdf/1603.08482v1
2016-03-28T18:55:02Z
2016-03-28T18:55:02Z
Estimating Mixture Models via Mixtures of Polynomials
Mixture modeling is a general technique for making any simple model more expressive through weighted combination. This generality and simplicity in part explains the success of the Expectation Maximization (EM) algorithm, in which updates are easy to derive for a wide class of mixture models. However, the likelihood of a mixture model is non-convex, so EM has no known global convergence guarantees. Recently, method of moments approaches offer global guarantees for some mixture models, but they do not extend easily to the range of mixture models that exist. In this work, we present Polymom, an unifying framework based on method of moments in which estimation procedures are easily derivable, just as in EM. Polymom is applicable when the moments of a single mixture component are polynomials of the parameters. Our key observation is that the moments of the mixture model are a mixture of these polynomials, which allows us to cast estimation as a Generalized Moment Problem. We solve its relaxations using semidefinite optimization, and then extract parameters using ideas from computer algebra. This framework allows us to draw insights and apply tools from convex optimization, computer algebra and the theory of moments to study problems in statistical estimation.
[ "Sida I. Wang and Arun Tejasvi Chaganty and Percy Liang", "['Sida I. Wang' 'Arun Tejasvi Chaganty' 'Percy Liang']" ]
cs.CV cs.AI cs.LG
null
1603.08561
null
null
http://arxiv.org/pdf/1603.08561v2
2016-07-26T17:26:01Z
2016-03-28T21:00:43Z
Shuffle and Learn: Unsupervised Learning using Temporal Order Verification
In this paper, we present an approach for learning a visual representation from the raw spatiotemporal signals in videos. Our representation is learned without supervision from semantic labels. We formulate our method as an unsupervised sequential verification task, i.e., we determine whether a sequence of frames from a video is in the correct temporal order. With this simple task and no semantic labels, we learn a powerful visual representation using a Convolutional Neural Network (CNN). The representation contains complementary information to that learned from supervised image datasets like ImageNet. Qualitative results show that our method captures information that is temporally varying, such as human pose. When used as pre-training for action recognition, our method gives significant gains over learning without external data on benchmark datasets like UCF101 and HMDB51. To demonstrate its sensitivity to human pose, we show results for pose estimation on the FLIC and MPII datasets that are competitive, or better than approaches using significantly more supervision. Our method can be combined with supervised representations to provide an additional boost in accuracy.
[ "['Ishan Misra' 'C. Lawrence Zitnick' 'Martial Hebert']", "Ishan Misra and C. Lawrence Zitnick and Martial Hebert" ]
cs.CV cs.LG
null
1603.08575
null
null
http://arxiv.org/pdf/1603.08575v3
2016-08-12T16:05:08Z
2016-03-28T21:59:08Z
Attend, Infer, Repeat: Fast Scene Understanding with Generative Models
We present a framework for efficient inference in structured image models that explicitly reason about objects. We achieve this by performing probabilistic inference using a recurrent neural network that attends to scene elements and processes them one at a time. Crucially, the model itself learns to choose the appropriate number of inference steps. We use this scheme to learn to perform inference in partially specified 2D models (variable-sized variational auto-encoders) and fully specified 3D models (probabilistic renderers). We show that such models learn to identify multiple objects - counting, locating and classifying the elements of a scene - without any supervision, e.g., decomposing 3D images with various numbers of objects in a single forward pass of a neural network. We further show that the networks produce accurate inferences when compared to supervised counterparts, and that their structure leads to improved generalization.
[ "S. M. Ali Eslami, Nicolas Heess, Theophane Weber, Yuval Tassa, David\n Szepesvari, Koray Kavukcuoglu and Geoffrey E. Hinton", "['S. M. Ali Eslami' 'Nicolas Heess' 'Theophane Weber' 'Yuval Tassa'\n 'David Szepesvari' 'Koray Kavukcuoglu' 'Geoffrey E. Hinton']" ]
cs.LG cs.CE
null
1603.08604
null
null
http://arxiv.org/pdf/1603.08604v2
2017-06-13T19:49:53Z
2016-03-29T01:26:04Z
Classification-based Financial Markets Prediction using Deep Neural Networks
Deep neural networks (DNNs) are powerful types of artificial neural networks (ANNs) that use several hidden layers. They have recently gained considerable attention in the speech transcription and image recognition community (Krizhevsky et al., 2012) for their superior predictive properties including robustness to overfitting. However their application to algorithmic trading has not been previously researched, partly because of their computational complexity. This paper describes the application of DNNs to predicting financial market movement directions. In particular we describe the configuration and training approach and then demonstrate their application to backtesting a simple trading strategy over 43 different Commodity and FX future mid-prices at 5-minute intervals. All results in this paper are generated using a C++ implementation on the Intel Xeon Phi co-processor which is 11.4x faster than the serial version and a Python strategy backtesting environment both of which are available as open source code written by the authors.
[ "Matthew Dixon, Diego Klabjan, Jin Hoon Bang", "['Matthew Dixon' 'Diego Klabjan' 'Jin Hoon Bang']" ]
cs.LG cs.DS cs.SI stat.ML
null
1603.08616
null
null
http://arxiv.org/pdf/1603.08616v2
2017-07-10T06:58:29Z
2016-03-29T02:13:17Z
Submodular Variational Inference for Network Reconstruction
In real-world and online social networks, individuals receive and transmit information in real time. Cascading information transmissions (e.g. phone calls, text messages, social media posts) may be understood as a realization of a diffusion process operating on the network, and its branching path can be represented by a directed tree. The process only traverses and thus reveals a limited portion of the edges. The network reconstruction/inference problem is to infer the unrevealed connections. Most existing approaches derive a likelihood and attempt to find the network topology maximizing the likelihood, a problem that is highly intractable. In this paper, we focus on the network reconstruction problem for a broad class of real-world diffusion processes, exemplified by a network diffusion scheme called respondent-driven sampling (RDS). We prove that under realistic and general models of network diffusion, the posterior distribution of an observed RDS realization is a Bayesian log-submodular model.We then propose VINE (Variational Inference for Network rEconstruction), a novel, accurate, and computationally efficient variational inference algorithm, for the network reconstruction problem under this model. Crucially, we do not assume any particular probabilistic model for the underlying network. VINE recovers any connected graph with high accuracy as shown by our experimental results on real-life networks.
[ "Lin Chen, Forrest W Crawford, Amin Karbasi", "['Lin Chen' 'Forrest W Crawford' 'Amin Karbasi']" ]
cs.LG math.ST stat.ML stat.TH
null
1603.08661
null
null
http://arxiv.org/pdf/1603.08661v2
2016-05-06T19:06:26Z
2016-03-29T07:12:14Z
Regret Analysis of the Anytime Optimally Confident UCB Algorithm
I introduce and analyse an anytime version of the Optimally Confident UCB (OCUCB) algorithm designed for minimising the cumulative regret in finite-armed stochastic bandits with subgaussian noise. The new algorithm is simple, intuitive (in hindsight) and comes with the strongest finite-time regret guarantees for a horizon-free algorithm so far. I also show a finite-time lower bound that nearly matches the upper bound.
[ "Tor Lattimore", "['Tor Lattimore']" ]
stat.ML cs.LG
null
1603.08704
null
null
http://arxiv.org/pdf/1603.08704v1
2016-03-29T10:04:07Z
2016-03-29T10:04:07Z
Interpretability of Multivariate Brain Maps in Brain Decoding: Definition and Quantification
Brain decoding is a popular multivariate approach for hypothesis testing in neuroimaging. It is well known that the brain maps derived from weights of linear classifiers are hard to interpret because of high correlations between predictors, low signal to noise ratios, and the high dimensionality of neuroimaging data. Therefore, improving the interpretability of brain decoding approaches is of primary interest in many neuroimaging studies. Despite extensive studies of this type, at present, there is no formal definition for interpretability of multivariate brain maps. As a consequence, there is no quantitative measure for evaluating the interpretability of different brain decoding methods. In this paper, first, we present a theoretical definition of interpretability in brain decoding; we show that the interpretability of multivariate brain maps can be decomposed into their reproducibility and representativeness. Second, as an application of the proposed theoretical definition, we formalize a heuristic method for approximating the interpretability of multivariate brain maps in a binary magnetoencephalography (MEG) decoding scenario. Third, we propose to combine the approximated interpretability and the performance of the brain decoding model into a new multi-objective criterion for model selection. Our results for the MEG data show that optimizing the hyper-parameters of the regularized linear classifier based on the proposed criterion results in more informative multivariate brain maps. More importantly, the presented definition provides the theoretical background for quantitative evaluation of interpretability, and hence, facilitates the development of more effective brain decoding algorithms in the future.
[ "Seyed Mostafa Kia", "['Seyed Mostafa Kia']" ]
cs.DC cs.LG
null
1603.08767
null
null
http://arxiv.org/pdf/1603.08767v1
2016-03-29T13:29:35Z
2016-03-29T13:29:35Z
Machine Learning and Cloud Computing: Survey of Distributed and SaaS Solutions
Applying popular machine learning algorithms to large amounts of data raised new challenges for the ML practitioners. Traditional ML libraries does not support well processing of huge datasets, so that new approaches were needed. Parallelization using modern parallel computing frameworks, such as MapReduce, CUDA, or Dryad gained in popularity and acceptance, resulting in new ML libraries developed on top of these frameworks. We will briefly introduce the most prominent industrial and academic outcomes, such as Apache Mahout, GraphLab or Jubatus. We will investigate how cloud computing paradigm impacted the field of ML. First direction is of popular statistics tools and libraries (R system, Python) deployed in the cloud. A second line of products is augmenting existing tools with plugins that allow users to create a Hadoop cluster in the cloud and run jobs on it. Next on the list are libraries of distributed implementations for ML algorithms, and on-premise deployments of complex systems for data analytics and data mining. Last approach on the radar of this survey is ML as Software-as-a-Service, several BigData start-ups (and large companies as well) already opening their solutions to the market.
[ "Daniel Pop", "['Daniel Pop']" ]
stat.CO cs.LG stat.ME
null
1603.08815
null
null
http://arxiv.org/pdf/1603.08815v1
2016-03-29T15:34:29Z
2016-03-29T15:34:29Z
Spectral M-estimation with Applications to Hidden Markov Models
Method of moment estimators exhibit appealing statistical properties, such as asymptotic unbiasedness, for nonconvex problems. However, they typically require a large number of samples and are extremely sensitive to model misspecification. In this paper, we apply the framework of M-estimation to develop both a generalized method of moments procedure and a principled method for regularization. Our proposed M-estimator obtains optimal sample efficiency rates (in the class of moment-based estimators) and the same well-known rates on prediction accuracy as other spectral estimators. It also makes it straightforward to incorporate regularization into the sample moment conditions. We demonstrate empirically the gains in sample efficiency from our approach on hidden Markov models.
[ "Dustin Tran, Minjae Kim, Finale Doshi-Velez", "['Dustin Tran' 'Minjae Kim' 'Finale Doshi-Velez']" ]
cs.LG
10.1016/j.neunet.2017.11.010
1603.08831
null
null
http://arxiv.org/abs/1603.08831v3
2017-08-10T22:57:16Z
2016-03-29T16:23:32Z
Towards Understanding Sparse Filtering: A Theoretical Perspective
In this paper we present a theoretical analysis to understand sparse filtering, a recent and effective algorithm for unsupervised learning. The aim of this research is not to show whether or how well sparse filtering works, but to understand why and when sparse filtering does work. We provide a thorough theoretical analysis of sparse filtering and its properties, and further offer an experimental validation of the main outcomes of our theoretical analysis. We show that sparse filtering works by explicitly maximizing the entropy of the learned representation through the maximization of the proxy of sparsity, and by implicitly preserving mutual information between original and learned representations through the constraint of preserving a structure of the data, specifically the structure defined by relations of neighborhoodness under the cosine distance. Furthermore, we empirically validate our theoretical results with artificial and real data sets, and we apply our theoretical understanding to explain the success of sparse filtering on real-world problems. Our work provides a strong theoretical basis for understanding sparse filtering: it highlights assumptions and conditions for success behind this feature distribution learning algorithm, and provides insights for developing new feature distribution learning algorithms.
[ "Fabio Massimo Zennaro, Ke Chen", "['Fabio Massimo Zennaro' 'Ke Chen']" ]
cs.LG
null
1603.08861
null
null
http://arxiv.org/pdf/1603.08861v2
2016-05-26T23:57:09Z
2016-03-29T17:46:16Z
Revisiting Semi-Supervised Learning with Graph Embeddings
We present a semi-supervised learning framework based on graph embeddings. Given a graph between instances, we train an embedding for each instance to jointly predict the class label and the neighborhood context in the graph. We develop both transductive and inductive variants of our method. In the transductive variant of our method, the class labels are determined by both the learned embeddings and input feature vectors, while in the inductive variant, the embeddings are defined as a parametric function of the feature vectors, so predictions can be made on instances not seen during training. On a large and diverse set of benchmark tasks, including text classification, distantly supervised entity extraction, and entity classification, we show improved performance over many of the existing models.
[ "Zhilin Yang and William W. Cohen and Ruslan Salakhutdinov", "['Zhilin Yang' 'William W. Cohen' 'Ruslan Salakhutdinov']" ]
cs.LG stat.ML
null
1603.08981
null
null
http://arxiv.org/pdf/1603.08981v2
2016-09-16T20:09:56Z
2016-03-29T21:54:56Z
Detecting weak changes in dynamic events over networks
Large volume of networked streaming event data are becoming increasingly available in a wide variety of applications, such as social network analysis, Internet traffic monitoring and healthcare analytics. Streaming event data are discrete observation occurred in continuous time, and the precise time interval between two events carries a great deal of information about the dynamics of the underlying systems. How to promptly detect changes in these dynamic systems using these streaming event data? In this paper, we propose a novel change-point detection framework for multi-dimensional event data over networks. We cast the problem into sequential hypothesis test, and derive the likelihood ratios for point processes, which are computed efficiently via an EM-like algorithm that is parameter-free and can be computed in a distributed fashion. We derive a highly accurate theoretical characterization of the false-alarm-rate, and show that it can achieve weak signal detection by aggregating local statistics over time and networks. Finally, we demonstrate the good performance of our algorithm on numerical examples and real-world datasets from twitter and Memetracker.
[ "['Shuang Li' 'Yao Xie' 'Mehrdad Farajtabar' 'Apurv Verma' 'Le Song']", "Shuang Li, Yao Xie, Mehrdad Farajtabar, Apurv Verma, and Le Song" ]
cs.AI cs.LG stat.ML
null
1603.08988
null
null
http://arxiv.org/pdf/1603.08988v1
2016-03-29T22:41:17Z
2016-03-29T22:41:17Z
Towards Practical Bayesian Parameter and State Estimation
Joint state and parameter estimation is a core problem for dynamic Bayesian networks. Although modern probabilistic inference toolkits make it relatively easy to specify large and practically relevant probabilistic models, the silver bullet---an efficient and general online inference algorithm for such problems---remains elusive, forcing users to write special-purpose code for each application. We propose a novel blackbox algorithm -- a hybrid of particle filtering for state variables and assumed density filtering for parameter variables. It has following advantages: (a) it is efficient due to its online nature, and (b) it is applicable to both discrete and continuous parameter spaces . On a variety of toy and real models, our system is able to generate more accurate results within a fixed computation budget. This preliminary evidence indicates that the proposed approach is likely to be of practical use.
[ "['Yusuf Bugra Erol' 'Yi Wu' 'Lei Li' 'Stuart Russell']", "Yusuf Bugra Erol, Yi Wu, Lei Li, Stuart Russell" ]
math.ST cs.LG stat.AP stat.ME stat.ML stat.TH
null
1603.09000
null
null
http://arxiv.org/pdf/1603.09000v3
2017-07-06T23:37:43Z
2016-03-29T23:41:51Z
Online Rules for Control of False Discovery Rate and False Discovery Exceedance
Multiple hypothesis testing is a core problem in statistical inference and arises in almost every scientific field. Given a set of null hypotheses $\mathcal{H}(n) = (H_1,\dotsc, H_n)$, Benjamini and Hochberg introduced the false discovery rate (FDR), which is the expected proportion of false positives among rejected null hypotheses, and proposed a testing procedure that controls FDR below a pre-assigned significance level. Nowadays FDR is the criterion of choice for large scale multiple hypothesis testing. In this paper we consider the problem of controlling FDR in an "online manner". Concretely, we consider an ordered --possibly infinite-- sequence of null hypotheses $\mathcal{H} = (H_1,H_2,H_3,\dots )$ where, at each step $i$, the statistician must decide whether to reject hypothesis $H_i$ having access only to the previous decisions. This model was introduced by Foster and Stine. We study a class of "generalized alpha-investing" procedures and prove that any rule in this class controls online FDR, provided $p$-values corresponding to true nulls are independent from the other $p$-values. (Earlier work only established mFDR control.) Next, we obtain conditions under which generalized alpha-investing controls FDR in the presence of general $p$-values dependencies. Finally, we develop a modified set of procedures that also allow to control the false discovery exceedance (the tail of the proportion of false discoveries). Numerical simulations and analytical results indicate that online procedures do not incur a large loss in statistical power with respect to offline approaches, such as Benjamini-Hochberg.
[ "['Adel Javanmard' 'Andrea Montanari']", "Adel Javanmard and Andrea Montanari" ]
cs.LG
null
1603.09025
null
null
http://arxiv.org/pdf/1603.09025v5
2017-02-28T00:59:42Z
2016-03-30T02:57:20Z
Recurrent Batch Normalization
We propose a reparameterization of LSTM that brings the benefits of batch normalization to recurrent neural networks. Whereas previous works only apply batch normalization to the input-to-hidden transformation of RNNs, we demonstrate that it is both possible and beneficial to batch-normalize the hidden-to-hidden transition, thereby reducing internal covariate shift between time steps. We evaluate our proposal on various sequential problems such as sequence classification, language modeling and question answering. Our empirical results show that our batch-normalized LSTM consistently leads to faster convergence and improved generalization.
[ "Tim Cooijmans, Nicolas Ballas, C\\'esar Laurent, \\c{C}a\\u{g}lar\n G\\\"ul\\c{c}ehre and Aaron Courville", "['Tim Cooijmans' 'Nicolas Ballas' 'César Laurent' 'Çağlar Gülçehre'\n 'Aaron Courville']" ]
cs.LG cs.DC stat.ML
null
1603.09035
null
null
http://arxiv.org/pdf/1603.09035v1
2016-03-30T04:05:29Z
2016-03-30T04:05:29Z
Towards Geo-Distributed Machine Learning
Latency to end-users and regulatory requirements push large companies to build data centers all around the world. The resulting data is "born" geographically distributed. On the other hand, many machine learning applications require a global view of such data in order to achieve the best results. These types of applications form a new class of learning problems, which we call Geo-Distributed Machine Learning (GDML). Such applications need to cope with: 1) scarce and expensive cross-data center bandwidth, and 2) growing privacy concerns that are pushing for stricter data sovereignty regulations. Current solutions to learning from geo-distributed data sources revolve around the idea of first centralizing the data in one data center, and then training locally. As machine learning algorithms are communication-intensive, the cost of centralizing the data is thought to be offset by the lower cost of intra-data center communication during training. In this work, we show that the current centralized practice can be far from optimal, and propose a system for doing geo-distributed training. Furthermore, we argue that the geo-distributed approach is structurally more amenable to dealing with regulatory constraints, as raw data never leaves the source data center. Our empirical evaluation on three real datasets confirms the general validity of our approach, and shows that GDML is not only possible but also advisable in many scenarios.
[ "['Ignacio Cano' 'Markus Weimer' 'Dhruv Mahajan' 'Carlo Curino'\n 'Giovanni Matteo Fumarola']", "Ignacio Cano, Markus Weimer, Dhruv Mahajan, Carlo Curino and Giovanni\n Matteo Fumarola" ]
cs.LG stat.ML
10.1007/s10994-017-5659-z
1603.09048
null
null
http://arxiv.org/abs/1603.09048v5
2017-08-05T04:05:40Z
2016-03-30T06:19:02Z
Cost-Sensitive Label Embedding for Multi-Label Classification
Label embedding (LE) is an important family of multi-label classification algorithms that digest the label information jointly for better performance. Different real-world applications evaluate performance by different cost functions of interest. Current LE algorithms often aim to optimize one specific cost function, but they can suffer from bad performance with respect to other cost functions. In this paper, we resolve the performance issue by proposing a novel cost-sensitive LE algorithm that takes the cost function of interest into account. The proposed algorithm, cost-sensitive label embedding with multidimensional scaling (CLEMS), approximates the cost information with the distances of the embedded vectors by using the classic multidimensional scaling approach for manifold learning. CLEMS is able to deal with both symmetric and asymmetric cost functions, and effectively makes cost-sensitive decisions by nearest-neighbor decoding within the embedded vectors. We derive theoretical results that justify how CLEMS achieves the desired cost-sensitivity. Furthermore, extensive experimental results demonstrate that CLEMS is significantly better than a wide spectrum of existing LE algorithms and state-of-the-art cost-sensitive algorithms across different cost functions.
[ "Kuan-Hao Huang and Hsuan-Tien Lin", "['Kuan-Hao Huang' 'Hsuan-Tien Lin']" ]
cs.LG stat.ML
null
1603.09050
null
null
http://arxiv.org/pdf/1603.09050v1
2016-03-30T06:21:42Z
2016-03-30T06:21:42Z
Robustness of Bayesian Pool-based Active Learning Against Prior Misspecification
We study the robustness of active learning (AL) algorithms against prior misspecification: whether an algorithm achieves similar performance using a perturbed prior as compared to using the true prior. In both the average and worst cases of the maximum coverage setting, we prove that all $\alpha$-approximate algorithms are robust (i.e., near $\alpha$-approximate) if the utility is Lipschitz continuous in the prior. We further show that robustness may not be achieved if the utility is non-Lipschitz. This suggests we should use a Lipschitz utility for AL if robustness is required. For the minimum cost setting, we can also obtain a robustness result for approximate AL algorithms. Our results imply that many commonly used AL algorithms are robust against perturbed priors. We then propose the use of a mixture prior to alleviate the problem of prior misspecification. We analyze the robustness of the uniform mixture prior and show experimentally that it performs reasonably well in practice.
[ "['Nguyen Viet Cuong' 'Nan Ye' 'Wee Sun Lee']", "Nguyen Viet Cuong, Nan Ye, Wee Sun Lee" ]
cs.LG
null
1603.09064
null
null
http://arxiv.org/pdf/1603.09064v5
2017-01-20T18:34:52Z
2016-03-30T07:51:58Z
Semi-Supervised Learning on Graphs through Reach and Distance Diffusion
Semi-supervised learning (SSL) is an indispensable tool when there are few labeled entities and many unlabeled entities for which we want to predict labels. With graph-based methods, entities correspond to nodes in a graph and edges represent strong relations. At the heart of SSL algorithms is the specification of a dense {\em kernel} of pairwise affinity values from the graph structure. A learning algorithm is then trained on the kernel together with labeled entities. The most popular kernels are {\em spectral} and include the highly scalable "symmetric" Laplacian methods, that compute a soft labels using Jacobi iterations, and "asymmetric" methods including Personalized Page Rank (PPR) which use short random walks and apply with directed relations, such as like, follow, or hyperlinks. We introduce {\em Reach diffusion} and {\em Distance diffusion} kernels that build on powerful social and economic models of centrality and influence in networks and capture the directed pairwise relations that underline social influence. Inspired by the success of social influence as an alternative to spectral centrality such as Page Rank, we explore SSL with our kernels and develop highly scalable algorithms for parameter setting, label learning, and sampling. We perform preliminary experiments that demonstrate the properties and potential of our kernels.
[ "Edith Cohen", "['Edith Cohen']" ]
cs.LG q-bio.GN
null
1603.09123
null
null
http://arxiv.org/pdf/1603.09123v2
2016-08-19T07:43:11Z
2016-03-30T10:59:36Z
deepTarget: End-to-end Learning Framework for microRNA Target Prediction using Deep Recurrent Neural Networks
MicroRNAs (miRNAs) are short sequences of ribonucleic acids that control the expression of target messenger RNAs (mRNAs) by binding them. Robust prediction of miRNA-mRNA pairs is of utmost importance in deciphering gene regulations but has been challenging because of high false positive rates, despite a deluge of computational tools that normally require laborious manual feature extraction. This paper presents an end-to-end machine learning framework for miRNA target prediction. Leveraged by deep recurrent neural networks-based auto-encoding and sequence-sequence interaction learning, our approach not only delivers an unprecedented level of accuracy but also eliminates the need for manual feature extraction. The performance gap between the proposed method and existing alternatives is substantial (over 25% increase in F-measure), and deepTarget delivers a quantum leap in the long-standing challenge of robust miRNA target prediction.
[ "Byunghan Lee, Junghwan Baek, Seunghyun Park, and Sungroh Yoon", "['Byunghan Lee' 'Junghwan Baek' 'Seunghyun Park' 'Sungroh Yoon']" ]
cs.CL cs.LG stat.ML
null
1603.09128
null
null
http://arxiv.org/pdf/1603.09128v1
2016-03-30T11:09:01Z
2016-03-30T11:09:01Z
Bilingual Learning of Multi-sense Embeddings with Discrete Autoencoders
We present an approach to learning multi-sense word embeddings relying both on monolingual and bilingual information. Our model consists of an encoder, which uses monolingual and bilingual context (i.e. a parallel sentence) to choose a sense for a given word, and a decoder which predicts context words based on the chosen sense. The two components are estimated jointly. We observe that the word representations induced from bilingual data outperform the monolingual counterparts across a range of evaluation tasks, even though crosslingual information is not available at test time.
[ "['Simon Šuster' 'Ivan Titov' 'Gertjan van Noord']", "Simon \\v{S}uster and Ivan Titov and Gertjan van Noord" ]
cs.CL cs.LG stat.ML
null
1603.09170
null
null
http://arxiv.org/pdf/1603.09170v5
2016-08-20T03:50:16Z
2016-03-30T13:09:20Z
Model Interpolation with Trans-dimensional Random Field Language Models for Speech Recognition
The dominant language models (LMs) such as n-gram and neural network (NN) models represent sentence probabilities in terms of conditionals. In contrast, a new trans-dimensional random field (TRF) LM has been recently introduced to show superior performances, where the whole sentence is modeled as a random field. In this paper, we examine how the TRF models can be interpolated with the NN models, and obtain 12.1\% and 17.9\% relative error rate reductions over 6-gram LMs for English and Chinese speech recognition respectively through log-linear combination.
[ "Bin Wang, Zhijian Ou, Yong He, Akinori Kawamura", "['Bin Wang' 'Zhijian Ou' 'Yong He' 'Akinori Kawamura']" ]
cs.LG
null
1603.09233
null
null
http://arxiv.org/pdf/1603.09233v1
2016-03-30T14:58:32Z
2016-03-30T14:58:32Z
Optimal Recommendation to Users that React: Online Learning for a Class of POMDPs
We describe and study a model for an Automated Online Recommendation System (AORS) in which a user's preferences can be time-dependent and can also depend on the history of past recommendations and play-outs. The three key features of the model that makes it more realistic compared to existing models for recommendation systems are (1) user preference is inherently latent, (2) current recommendations can affect future preferences, and (3) it allows for the development of learning algorithms with provable performance guarantees. The problem is cast as an average-cost restless multi-armed bandit for a given user, with an independent partially observable Markov decision process (POMDP) for each item of content. We analyze the POMDP for a single arm, describe its structural properties, and characterize its optimal policy. We then develop a Thompson sampling-based online reinforcement learning algorithm to learn the parameters of the model and optimize utility from the binary responses of the users to continuous recommendations. We then analyze the performance of the learning algorithm and characterize the regret. Illustrative numerical results and directions for extension to the restless hidden Markov multi-armed bandit problem are also presented.
[ "['Rahul Meshram' 'Aditya Gopalan' 'D. Manjunath']", "Rahul Meshram, Aditya Gopalan and D. Manjunath" ]
cs.LG stat.ML
null
1603.09260
null
null
http://arxiv.org/pdf/1603.09260v2
2016-06-03T14:45:35Z
2016-03-30T16:16:57Z
Degrees of Freedom in Deep Neural Networks
In this paper, we explore degrees of freedom in deep sigmoidal neural networks. We show that the degrees of freedom in these models is related to the expected optimism, which is the expected difference between test error and training error. We provide an efficient Monte-Carlo method to estimate the degrees of freedom for multi-class classification methods. We show degrees of freedom are lower than the parameter count in a simple XOR network. We extend these results to neural nets trained on synthetic and real data, and investigate impact of network's architecture and different regularization choices. The degrees of freedom in deep networks are dramatically smaller than the number of parameters, in some real datasets several orders of magnitude. Further, we observe that for fixed number of parameters, deeper networks have less degrees of freedom exhibiting a regularization-by-depth.
[ "['Tianxiang Gao' 'Vladimir Jojic']", "Tianxiang Gao and Vladimir Jojic" ]
cs.LG cs.CL cs.NE
null
1603.09381
null
null
http://arxiv.org/pdf/1603.09381v1
2016-03-30T20:57:07Z
2016-03-30T20:57:07Z
Clinical Information Extraction via Convolutional Neural Network
We report an implementation of a clinical information extraction tool that leverages deep neural network to annotate event spans and their attributes from raw clinical notes and pathology reports. Our approach uses context words and their part-of-speech tags and shape information as features. Then we hire temporal (1D) convolutional neural network to learn hidden feature representations. Finally, we use Multilayer Perceptron (MLP) to predict event spans. The empirical evaluation demonstrates that our approach significantly outperforms baselines.
[ "Peng Li and Heng Huang", "['Peng Li' 'Heng Huang']" ]
cs.LG cs.CV cs.NE
null
1603.09382
null
null
http://arxiv.org/pdf/1603.09382v3
2016-07-28T23:24:16Z
2016-03-30T20:58:07Z
Deep Networks with Stochastic Depth
Very deep convolutional networks with hundreds of layers have led to significant reductions in error on competitive benchmarks. Although the unmatched expressiveness of the many layers can be highly desirable at test time, training very deep networks comes with its own set of challenges. The gradients can vanish, the forward flow often diminishes, and the training time can be painfully slow. To address these problems, we propose stochastic depth, a training procedure that enables the seemingly contradictory setup to train short networks and use deep networks at test time. We start with very deep networks but during training, for each mini-batch, randomly drop a subset of layers and bypass them with the identity function. This simple approach complements the recent success of residual networks. It reduces training time substantially and improves the test error significantly on almost all data sets that we used for evaluation. With stochastic depth we can increase the depth of residual networks even beyond 1200 layers and still yield meaningful improvements in test error (4.91% on CIFAR-10).
[ "Gao Huang, Yu Sun, Zhuang Liu, Daniel Sedra, Kilian Weinberger", "['Gao Huang' 'Yu Sun' 'Zhuang Liu' 'Daniel Sedra' 'Kilian Weinberger']" ]
cs.NE cs.LG
null
1603.09420
null
null
http://arxiv.org/pdf/1603.09420v1
2016-03-31T00:01:10Z
2016-03-31T00:01:10Z
Minimal Gated Unit for Recurrent Neural Networks
Recently recurrent neural networks (RNN) has been very successful in handling sequence data. However, understanding RNN and finding the best practices for RNN is a difficult task, partly because there are many competing and complex hidden units (such as LSTM and GRU). We propose a gated unit for RNN, named as Minimal Gated Unit (MGU), since it only contains one gate, which is a minimal design among all gated hidden units. The design of MGU benefits from evaluation results on LSTM and GRU in the literature. Experiments on various sequence data show that MGU has comparable accuracy with GRU, but has a simpler structure, fewer parameters, and faster training. Hence, MGU is suitable in RNN's applications. Its simple architecture also means that it is easier to evaluate and tune, and in principle it is easier to study MGU's properties theoretically and empirically.
[ "['Guo-Bing Zhou' 'Jianxin Wu' 'Chen-Lin Zhang' 'Zhi-Hua Zhou']", "Guo-Bing Zhou and Jianxin Wu and Chen-Lin Zhang and Zhi-Hua Zhou" ]
cs.LG stat.ML
null
1603.09441
null
null
http://arxiv.org/pdf/1603.09441v1
2016-03-31T02:23:24Z
2016-03-31T02:23:24Z
A Stratified Analysis of Bayesian Optimization Methods
Empirical analysis serves as an important complement to theoretical analysis for studying practical Bayesian optimization. Often empirical insights expose strengths and weaknesses inaccessible to theoretical analysis. We define two metrics for comparing the performance of Bayesian optimization methods and propose a ranking mechanism for summarizing performance within various genres or strata of test functions. These test functions serve to mimic the complexity of hyperparameter optimization problems, the most prominent application of Bayesian optimization, but with a closed form which allows for rapid evaluation and more predictable behavior. This offers a flexible and efficient way to investigate functions with specific properties of interest, such as oscillatory behavior or an optimum on the domain boundary.
[ "Ian Dewancker, Michael McCourt, Scott Clark, Patrick Hayes, Alexandra\n Johnson and George Ke", "['Ian Dewancker' 'Michael McCourt' 'Scott Clark' 'Patrick Hayes'\n 'Alexandra Johnson' 'George Ke']" ]
cs.CV cs.LG
10.1016/j.jvcir.2017.02.014
1603.09469
null
null
http://arxiv.org/abs/1603.09469v1
2016-03-31T06:55:25Z
2016-03-31T06:55:25Z
A ParaBoost Stereoscopic Image Quality Assessment (PBSIQA) System
The problem of stereoscopic image quality assessment, which finds applications in 3D visual content delivery such as 3DTV, is investigated in this work. Specifically, we propose a new ParaBoost (parallel-boosting) stereoscopic image quality assessment (PBSIQA) system. The system consists of two stages. In the first stage, various distortions are classified into a few types, and individual quality scorers targeting at a specific distortion type are developed. These scorers offer complementary performance in face of a database consisting of heterogeneous distortion types. In the second stage, scores from multiple quality scorers are fused to achieve the best overall performance, where the fuser is designed based on the parallel boosting idea borrowed from machine learning. Extensive experimental results are conducted to compare the performance of the proposed PBSIQA system with those of existing stereo image quality assessment (SIQA) metrics. The developed quality metric can serve as an objective function to optimize the performance of a 3D content delivery system.
[ "Hyunsuk Ko, Rui Song, C.-C. Jay Kuo", "['Hyunsuk Ko' 'Rui Song' 'C. -C. Jay Kuo']" ]
cs.IR cs.CV cs.LG
null
1603.09473
null
null
http://arxiv.org/pdf/1603.09473v3
2016-09-29T00:43:21Z
2016-03-31T07:22:30Z
Learning Compatibility Across Categories for Heterogeneous Item Recommendation
Identifying relationships between items is a key task of an online recommender system, in order to help users discover items that are functionally complementary or visually compatible. In domains like clothing recommendation, this task is particularly challenging since a successful system should be capable of handling a large corpus of items, a huge amount of relationships among them, as well as the high-dimensional and semantically complicated features involved. Furthermore, the human notion of "compatibility" to capture goes beyond mere similarity: For two items to be compatible---whether jeans and a t-shirt, or a laptop and a charger---they should be similar in some ways, but systematically different in others. In this paper we propose a novel method, Monomer, to learn complicated and heterogeneous relationships between items in product recommendation settings. Recently, scalable methods have been developed that address this task by learning similarity metrics on top of the content of the products involved. Here our method relaxes the metricity assumption inherent in previous work and models multiple localized notions of 'relatedness,' so as to uncover ways in which related items should be systematically similar, and systematically different. Quantitatively, we show that our system achieves state-of-the-art performance on large-scale compatibility prediction tasks, especially in cases where there is substantial heterogeneity between related items. Qualitatively, we demonstrate that richer notions of compatibility can be learned that go beyond similarity, and that our model can make effective recommendations of heterogeneous content.
[ "['Ruining He' 'Charles Packer' 'Julian McAuley']", "Ruining He and Charles Packer and Julian McAuley" ]
cs.CL cs.LG cs.NE cs.SD
null
1603.09509
null
null
http://arxiv.org/pdf/1603.09509v2
2016-04-05T14:17:09Z
2016-03-31T09:54:44Z
Learning Multiscale Features Directly From Waveforms
Deep learning has dramatically improved the performance of speech recognition systems through learning hierarchies of features optimized for the task at hand. However, true end-to-end learning, where features are learned directly from waveforms, has only recently reached the performance of hand-tailored representations based on the Fourier transform. In this paper, we detail an approach to use convolutional filters to push past the inherent tradeoff of temporal and frequency resolution that exists for spectral representations. At increased computational cost, we show that increasing temporal resolution via reduced stride and increasing frequency resolution via additional filters delivers significant performance improvements. Further, we find more efficient representations by simultaneously learning at multiple scales, leading to an overall decrease in word error rate on a difficult internal speech test set by 20.7% relative to networks with the same number of parameters trained on spectrograms.
[ "Zhenyao Zhu, Jesse H. Engel, Awni Hannun", "['Zhenyao Zhu' 'Jesse H. Engel' 'Awni Hannun']" ]
cs.LG math.OC stat.ML
null
1603.09620
null
null
http://arxiv.org/pdf/1603.09620v3
2016-09-29T11:13:00Z
2016-03-31T15:00:06Z
Online Optimization with Costly and Noisy Measurements using Random Fourier Expansions
This paper analyzes DONE, an online optimization algorithm that iteratively minimizes an unknown function based on costly and noisy measurements. The algorithm maintains a surrogate of the unknown function in the form of a random Fourier expansion (RFE). The surrogate is updated whenever a new measurement is available, and then used to determine the next measurement point. The algorithm is comparable to Bayesian optimization algorithms, but its computational complexity per iteration does not depend on the number of measurements. We derive several theoretical results that provide insight on how the hyper-parameters of the algorithm should be chosen. The algorithm is compared to a Bayesian optimization algorithm for a benchmark problem and three applications, namely, optical coherence tomography, optical beam-forming network tuning, and robot arm control. It is found that the DONE algorithm is significantly faster than Bayesian optimization in the discussed problems, while achieving a similar or better performance.
[ "['Laurens Bliek' 'Hans R. G. W. Verstraete' 'Michel Verhaegen'\n 'Sander Wahls']", "Laurens Bliek, Hans R. G. W. Verstraete, Michel Verhaegen, and Sander\n Wahls" ]
cs.CL cs.LG
10.1109/TASLP.2016.2584700
1603.09630
null
null
http://arxiv.org/abs/1603.09630v2
2016-07-13T18:12:49Z
2016-03-31T15:10:40Z
Differentiable Pooling for Unsupervised Acoustic Model Adaptation
We present a deep neural network (DNN) acoustic model that includes parametrised and differentiable pooling operators. Unsupervised acoustic model adaptation is cast as the problem of updating the decision boundaries implemented by each pooling operator. In particular, we experiment with two types of pooling parametrisations: learned $L_p$-norm pooling and weighted Gaussian pooling, in which the weights of both operators are treated as speaker-dependent. We perform investigations using three different large vocabulary speech recognition corpora: AMI meetings, TED talks and Switchboard conversational telephone speech. We demonstrate that differentiable pooling operators provide a robust and relatively low-dimensional way to adapt acoustic models, with relative word error rates reductions ranging from 5--20% with respect to unadapted systems, which themselves are better than the baseline fully-connected DNN-based acoustic models. We also investigate how the proposed techniques work under various adaptation conditions including the quality of adaptation data and complementarity to other feature- and model-space adaptation methods, as well as providing an analysis of the characteristics of each of the proposed approaches.
[ "['Pawel Swietojanski' 'Steve Renals']", "Pawel Swietojanski and Steve Renals" ]
cs.CL cs.LG
null
1603.09631
null
null
http://arxiv.org/pdf/1603.09631v2
2016-05-15T13:03:26Z
2016-03-31T15:13:51Z
Data Collection for Interactive Learning through the Dialog
This paper presents a dataset collected from natural dialogs which enables to test the ability of dialog systems to learn new facts from user utterances throughout the dialog. This interactive learning will help with one of the most prevailing problems of open domain dialog system, which is the sparsity of facts a dialog system can reason about. The proposed dataset, consisting of 1900 collected dialogs, allows simulation of an interactive gaining of denotations and questions explanations from users which can be used for the interactive learning.
[ "Miroslav Vodol\\'an, Filip Jur\\v{c}\\'i\\v{c}ek", "['Miroslav Vodolán' 'Filip Jurčíček']" ]
cs.CR cs.LG stat.ML
null
1603.09638
null
null
http://arxiv.org/pdf/1603.09638v4
2018-03-31T02:12:21Z
2016-03-31T15:28:45Z
Detection under Privileged Information
For well over a quarter century, detection systems have been driven by models learned from input features collected from real or simulated environments. An artifact (e.g., network event, potential malware sample, suspicious email) is deemed malicious or non-malicious based on its similarity to the learned model at runtime. However, the training of the models has been historically limited to only those features available at runtime. In this paper, we consider an alternate learning approach that trains models using "privileged" information--features available at training time but not at runtime--to improve the accuracy and resilience of detection systems. In particular, we adapt and extend recent advances in knowledge transfer, model influence, and distillation to enable the use of forensic or other data unavailable at runtime in a range of security domains. An empirical evaluation shows that privileged information increases precision and recall over a system with no privileged information: we observe up to 7.7% relative decrease in detection error for fast-flux bot detection, 8.6% for malware traffic detection, 7.3% for malware classification, and 16.9% for face recognition. We explore the limitations and applications of different privileged information techniques in detection systems. Such techniques provide a new means for detection systems to learn from data that would otherwise not be available at runtime.
[ "['Z. Berkay Celik' 'Patrick McDaniel' 'Rauf Izmailov' 'Nicolas Papernot'\n 'Ryan Sheatsley' 'Raquel Alvarez' 'Ananthram Swami']", "Z. Berkay Celik, Patrick McDaniel, Rauf Izmailov, Nicolas Papernot,\n Ryan Sheatsley, Raquel Alvarez, Ananthram Swami" ]
cs.CL cs.LG cs.NE stat.ML
null
1603.09643
null
null
http://arxiv.org/pdf/1603.09643v4
2016-09-27T12:27:17Z
2016-03-31T15:37:29Z
Multi-task Recurrent Model for Speech and Speaker Recognition
Although highly correlated, speech and speaker recognition have been regarded as two independent tasks and studied by two communities. This is certainly not the way that people behave: we decipher both speech content and speaker traits at the same time. This paper presents a unified model to perform speech and speaker recognition simultaneously and altogether. The model is based on a unified neural network where the output of one task is fed to the input of the other, leading to a multi-task recurrent network. Experiments show that the joint model outperforms the task-specific models on both the two tasks.
[ "Zhiyuan Tang, Lantian Li and Dong Wang", "['Zhiyuan Tang' 'Lantian Li' 'Dong Wang']" ]
cs.LG
null
1603.09738
null
null
http://arxiv.org/pdf/1603.09738v2
2017-04-19T13:53:01Z
2016-03-31T19:48:13Z
Pessimistic Uplift Modeling
Uplift modeling is a machine learning technique that aims to model treatment effects heterogeneity. It has been used in business and health sectors to predict the effect of a specific action on a given individual. Despite its advantages, uplift models show high sensitivity to noise and disturbance, which leads to unreliable results. In this paper we show different approaches to address the problem of uplift modeling, we demonstrate how disturbance in data can affect uplift measurement. We propose a new approach, we call it Pessimistic Uplift Modeling, that minimizes disturbance effects. We compared our approach with the existing uplift methods, on simulated and real data-sets. The experiments show that our approach outperforms the existing approaches, especially in the case of high noise data environment.
[ "['Atef Shaar' 'Talel Abdessalem' 'Olivier Segard']", "Atef Shaar, Talel Abdessalem, Olivier Segard" ]
cs.LG cs.IT math.IT stat.ML
null
1603.09739
null
null
http://arxiv.org/pdf/1603.09739v1
2016-03-31T19:50:45Z
2016-03-31T19:50:45Z
Hierarchical Quickest Change Detection via Surrogates
Change detection (CD) in time series data is a critical problem as it reveal changes in the underlying generative processes driving the time series. Despite having received significant attention, one important unexplored aspect is how to efficiently utilize additional correlated information to improve the detection and the understanding of changepoints. We propose hierarchical quickest change detection (HQCD), a framework that formalizes the process of incorporating additional correlated sources for early changepoint detection. The core ideas behind HQCD are rooted in the theory of quickest detection and HQCD can be regarded as its novel generalization to a hierarchical setting. The sources are classified into targets and surrogates, and HQCD leverages this structure to systematically assimilate observed data to update changepoint statistics across layers. The decision on actual changepoints are provided by minimizing the delay while still maintaining reliability bounds. In addition, HQCD also uncovers interesting relations between changes at targets from changes across surrogates. We validate HQCD for reliability and performance against several state-of-the-art methods for both synthetic dataset (known changepoints) and several real-life examples (unknown changepoints). Our experiments indicate that we gain significant robustness without loss of detection delay through HQCD. Our real-life experiments also showcase the usefulness of the hierarchical setting by connecting the surrogate sources (such as Twitter chatter) to target sources (such as Employment related protests that ultimately lead to major uprisings).
[ "Prithwish Chakraborty and Sathappan Muthiah and Ravi Tandon and Naren\n Ramakrishnan", "['Prithwish Chakraborty' 'Sathappan Muthiah' 'Ravi Tandon'\n 'Naren Ramakrishnan']" ]
cs.CV cs.LG
null
1604.00092
null
null
http://arxiv.org/pdf/1604.00092v1
2016-04-01T01:04:31Z
2016-04-01T01:04:31Z
Variational reaction-diffusion systems for semantic segmentation
A novel global energy model for multi-class semantic image segmentation is proposed that admits very efficient exact inference and derivative calculations for learning. Inference in this model is equivalent to MAP inference in a particular kind of vector-valued Gaussian Markov random field, and ultimately reduces to solving a linear system of linear PDEs known as a reaction-diffusion system. Solving this system can be achieved in time scaling near-linearly in the number of image pixels by reducing it to sequential FFTs, after a linear change of basis. The efficiency and differentiability of the model make it especially well-suited for integration with convolutional neural networks, even allowing it to be used in interior, feature-generating layers and stacked multiple times. Experimental results are shown demonstrating that the model can be employed profitably in conjunction with different convolutional net architectures, and that doing so compares favorably to joint training of a fully-connected CRF with a convolutional net.
[ "Paul Vernaza", "['Paul Vernaza']" ]
cs.CL cs.IR cs.LG cs.SI
null
1604.00119
null
null
http://arxiv.org/pdf/1604.00119v3
2016-04-24T21:27:17Z
2016-04-01T03:32:03Z
Semi-supervised and Unsupervised Methods for Categorizing Posts in Web Discussion Forums
Web discussion forums are used by millions of people worldwide to share information belonging to a variety of domains such as automotive vehicles, pets, sports, etc. They typically contain posts that fall into different categories such as problem, solution, feedback, spam, etc. Automatic identification of these categories can aid information retrieval that is tailored for specific user requirements. Previously, a number of supervised methods have attempted to solve this problem; however, these depend on the availability of abundant training data. A few existing unsupervised and semi-supervised approaches are either focused on identifying a single category or do not report category-specific performance. In contrast, this work proposes unsupervised and semi-supervised methods that require no or minimal training data to achieve this objective without compromising on performance. A fine-grained analysis is also carried out to discuss their limitations. The proposed methods are based on sequence models (specifically, Hidden Markov Models) that can model language for each category using word and part-of-speech probability distributions, and manually specified features. Empirical evaluations across domains demonstrate that the proposed methods are better suited for this task than existing ones.
[ "Krish Perumal", "['Krish Perumal']" ]
cs.CL cs.IR cs.LG stat.ML
null
1604.00126
null
null
http://arxiv.org/pdf/1604.00126v1
2016-04-01T04:36:58Z
2016-04-01T04:36:58Z
Nonparametric Spherical Topic Modeling with Word Embeddings
Traditional topic models do not account for semantic regularities in language. Recent distributional representations of words exhibit semantic consistency over directional metrics such as cosine similarity. However, neither categorical nor Gaussian observational distributions used in existing topic models are appropriate to leverage such correlations. In this paper, we propose to use the von Mises-Fisher distribution to model the density of words over a unit sphere. Such a representation is well-suited for directional data. We use a Hierarchical Dirichlet Process for our base topic model and propose an efficient inference algorithm based on Stochastic Variational Inference. This model enables us to naturally exploit the semantic structures of word embeddings while flexibly discovering the number of topics. Experiments demonstrate that our method outperforms competitive approaches in terms of topic coherence on two different text corpora while offering efficient inference.
[ "Kayhan Batmanghelich, Ardavan Saeedi, Karthik Narasimhan, Sam Gershman", "['Kayhan Batmanghelich' 'Ardavan Saeedi' 'Karthik Narasimhan'\n 'Sam Gershman']" ]
quant-ph cs.LG cs.NE
10.1103/PhysRevA.95.012335
1604.00279
null
null
http://arxiv.org/abs/1604.00279v2
2016-09-17T14:44:36Z
2016-04-01T15:24:27Z
Using Recurrent Neural Networks to Optimize Dynamical Decoupling for Quantum Memory
We utilize machine learning models which are based on recurrent neural networks to optimize dynamical decoupling (DD) sequences. DD is a relatively simple technique for suppressing the errors in quantum memory for certain noise models. In numerical simulations, we show that with minimum use of prior knowledge and starting from random sequences, the models are able to improve over time and eventually output DD-sequences with performance better than that of the well known DD-families. Furthermore, our algorithm is easy to implement in experiments to find solutions tailored to the specific hardware, as it treats the figure of merit as a black box.
[ "Moritz August, Xiaotong Ni", "['Moritz August' 'Xiaotong Ni']" ]
cs.AI cs.CV cs.LG cs.NE stat.ML
null
1604.00289
null
null
http://arxiv.org/pdf/1604.00289v3
2016-11-02T17:26:50Z
2016-04-01T15:37:57Z
Building Machines That Learn and Think Like People
Recent progress in artificial intelligence (AI) has renewed interest in building systems that learn and think like people. Many advances have come from using deep neural networks trained end-to-end in tasks such as object recognition, video games, and board games, achieving performance that equals or even beats humans in some respects. Despite their biological inspiration and performance achievements, these systems differ from human intelligence in crucial ways. We review progress in cognitive science suggesting that truly human-like learning and thinking machines will have to reach beyond current engineering trends in both what they learn, and how they learn it. Specifically, we argue that these machines should (a) build causal models of the world that support explanation and understanding, rather than merely solving pattern recognition problems; (b) ground learning in intuitive theories of physics and psychology, to support and enrich the knowledge that is learned; and (c) harness compositionality and learning-to-learn to rapidly acquire and generalize knowledge to new tasks and situations. We suggest concrete challenges and promising routes towards these goals that can combine the strengths of recent neural network advances with more structured cognitive models.
[ "Brenden M. Lake, Tomer D. Ullman, Joshua B. Tenenbaum, Samuel J.\n Gershman", "['Brenden M. Lake' 'Tomer D. Ullman' 'Joshua B. Tenenbaum'\n 'Samuel J. Gershman']" ]
cs.CL cs.LG cs.NE
null
1604.00317
null
null
http://arxiv.org/pdf/1604.00317v1
2016-04-01T16:26:57Z
2016-04-01T16:26:57Z
A Semisupervised Approach for Language Identification based on Ladder Networks
In this study we address the problem of training a neuralnetwork for language identification using both labeled and unlabeled speech samples in the form of i-vectors. We propose a neural network architecture that can also handle out-of-set languages. We utilize a modified version of the recently proposed Ladder Network semisupervised training procedure that optimizes the reconstruction costs of a stack of denoising autoencoders. We show that this approach can be successfully applied to the case where the training dataset is composed of both labeled and unlabeled acoustic data. The results show enhanced language identification on the NIST 2015 language identification dataset.
[ "['Ehud Ben-Reuven' 'Jacob Goldberger']", "Ehud Ben-Reuven and Jacob Goldberger" ]
cs.CL cs.AI cs.LG
null
1604.00461
null
null
http://arxiv.org/pdf/1604.00461v1
2016-04-02T04:59:21Z
2016-04-02T04:59:21Z
Embedding Lexical Features via Low-Rank Tensors
Modern NLP models rely heavily on engineered features, which often combine word and contextual information into complex lexical features. Such combination results in large numbers of features, which can lead to over-fitting. We present a new model that represents complex lexical features---comprised of parts for words, contextual information and labels---in a tensor that captures conjunction information among these parts. We apply low-rank tensor approximations to the corresponding parameter tensors to reduce the parameter space and improve prediction speed. Furthermore, we investigate two methods for handling features that include $n$-grams of mixed lengths. Our model achieves state-of-the-art results on tasks in relation extraction, PP-attachment, and preposition disambiguation.
[ "Mo Yu, Mark Dredze, Raman Arora, Matthew Gormley", "['Mo Yu' 'Mark Dredze' 'Raman Arora' 'Matthew Gormley']" ]