October 16, 2019

2709 words 13 mins read

Paper Group ANR 1146

Paper Group ANR 1146

Modeling human intuitions about liquid flow with particle-based simulation. A Semi-Markov Chain Approach to Modeling Respiratory Patterns Prior to Extubation in Preterm Infants. A Survey of Mobile Computing for the Visually Impaired. Towards Understanding and Answering Multi-Sentence Recommendation Questions on Tourism. Deja Vu: Motion Prediction i …

Modeling human intuitions about liquid flow with particle-based simulation

Title Modeling human intuitions about liquid flow with particle-based simulation
Authors Christopher J. Bates, Ilker Yildirim, Joshua B. Tenenbaum, Peter Battaglia
Abstract Humans can easily describe, imagine, and, crucially, predict a wide variety of behaviors of liquids–splashing, squirting, gushing, sloshing, soaking, dripping, draining, trickling, pooling, and pouring–despite tremendous variability in their material and dynamical properties. Here we propose and test a computational model of how people perceive and predict these liquid dynamics, based on coarse approximate simulations of fluids as collections of interacting particles. Our model is analogous to a “game engine in the head”, drawing on techniques for interactive simulations (as in video games) that optimize for efficiency and natural appearance rather than physical accuracy. In two behavioral experiments, we found that the model accurately captured people’s predictions about how liquids flow among complex solid obstacles, and was significantly better than two alternatives based on simple heuristics and deep neural networks. Our model was also able to explain how people’s predictions varied as a function of the liquids’ properties (e.g., viscosity and stickiness). Together, the model and empirical results extend the recent proposal that human physical scene understanding for the dynamics of rigid, solid objects can be supported by approximate probabilistic simulation, to the more complex and unexplored domain of fluid dynamics.
Tasks Scene Understanding
Published 2018-09-05
URL http://arxiv.org/abs/1809.01524v1
PDF http://arxiv.org/pdf/1809.01524v1.pdf
PWC https://paperswithcode.com/paper/modeling-human-intuitions-about-liquid-flow
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A Semi-Markov Chain Approach to Modeling Respiratory Patterns Prior to Extubation in Preterm Infants

Title A Semi-Markov Chain Approach to Modeling Respiratory Patterns Prior to Extubation in Preterm Infants
Authors Charles C. Onu, Lara J. Kanbar, Wissam Shalish, Karen A. Brown, Guilherme M. Sant’Anna, Robert E. Kearney, Doina Precup
Abstract After birth, extremely preterm infants often require specialized respiratory management in the form of invasive mechanical ventilation (IMV). Protracted IMV is associated with detrimental outcomes and morbidities. Premature extubation, on the other hand, would necessitate reintubation which is risky, technically challenging and could further lead to lung injury or disease. We present an approach to modeling respiratory patterns of infants who succeeded extubation and those who required reintubation which relies on Markov models. We compare the use of traditional Markov chains to semi-Markov models which emphasize cross-pattern transitions and timing information, and to multi-chain Markov models which can concisely represent non-stationarity in respiratory behavior over time. The models we developed expose specific, unique similarities as well as vital differences between the two populations.
Tasks
Published 2018-08-24
URL http://arxiv.org/abs/1808.07989v1
PDF http://arxiv.org/pdf/1808.07989v1.pdf
PWC https://paperswithcode.com/paper/a-semi-markov-chain-approach-to-modeling
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A Survey of Mobile Computing for the Visually Impaired

Title A Survey of Mobile Computing for the Visually Impaired
Authors Martin Weiss, Margaux Luck, Roger Girgis, Chris Pal, Joseph Paul Cohen
Abstract The number of visually impaired or blind (VIB) people in the world is estimated at several hundred million. Based on a series of interviews with the VIB and developers of assistive technology, this paper provides a survey of machine-learning based mobile applications and identifies the most relevant applications. We discuss the functionality of these apps, how they align with the needs and requirements of the VIB users, and how they can be improved with techniques such as federated learning and model compression. As a result of this study we identify promising future directions of research in mobile perception, micro-navigation, and content-summarization.
Tasks Model Compression
Published 2018-11-25
URL http://arxiv.org/abs/1811.10120v2
PDF http://arxiv.org/pdf/1811.10120v2.pdf
PWC https://paperswithcode.com/paper/a-survey-of-mobile-computing-for-the-visually
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Towards Understanding and Answering Multi-Sentence Recommendation Questions on Tourism

Title Towards Understanding and Answering Multi-Sentence Recommendation Questions on Tourism
Authors Danish Contractor, Barun Patra, Mausam Singla, Parag Singla
Abstract We introduce the first system towards the novel task of answering complex multisentence recommendation questions in the tourism domain. Our solution uses a pipeline of two modules: question understanding and answering. For question understanding, we define an SQL-like query language that captures the semantic intent of a question; it supports operators like subset, negation, preference and similarity, which are often found in recommendation questions. We train and compare traditional CRFs as well as bidirectional LSTM-based models for converting a question to its semantic representation. We extend these models to a semisupervised setting with partially labeled sequences gathered through crowdsourcing. We find that our best model performs semi-supervised training of BiDiLSTM+CRF with hand-designed features and CCM(Chang et al., 2007) constraints. Finally, in an end to end QA system, our answering component converts our question representation into queries fired on underlying knowledge sources. Our experiments on two different answer corpora demonstrate that our system can significantly outperform baselines with up to 20 pt higher accuracy and 17 pt higher recall.
Tasks
Published 2018-01-05
URL http://arxiv.org/abs/1801.01825v1
PDF http://arxiv.org/pdf/1801.01825v1.pdf
PWC https://paperswithcode.com/paper/towards-understanding-and-answering-multi
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Deja Vu: Motion Prediction in Static Images

Title Deja Vu: Motion Prediction in Static Images
Authors Silvia L. Pintea, Jan C. van Gemert, Arnold W. M. Smeulders
Abstract This paper proposes motion prediction in single still images by learning it from a set of videos. The building assumption is that similar motion is characterized by similar appearance. The proposed method learns local motion patterns given a specific appearance and adds the predicted motion in a number of applications. This work (i) introduces a novel method to predict motion from appearance in a single static image, (ii) to that end, extends of the Structured Random Forest with regression derived from first principles, and (iii) shows the value of adding motion predictions in different tasks such as: weak frame-proposals containing unexpected events, action recognition, motion saliency. Illustrative results indicate that motion prediction is not only feasible, but also provides valuable information for a number of applications.
Tasks motion prediction, Temporal Action Localization
Published 2018-03-19
URL http://arxiv.org/abs/1803.06951v2
PDF http://arxiv.org/pdf/1803.06951v2.pdf
PWC https://paperswithcode.com/paper/deja-vu-motion-prediction-in-static-images
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Visual Affordance and Function Understanding: A Survey

Title Visual Affordance and Function Understanding: A Survey
Authors Mohammed Hassanin, Salman Khan, Murat Tahtali
Abstract Nowadays, robots are dominating the manufacturing, entertainment and healthcare industries. Robot vision aims to equip robots with the ability to discover information, understand it and interact with the environment. These capabilities require an agent to effectively understand object affordances and functionalities in complex visual domains. In this literature survey, we first focus on Visual affordances and summarize the state of the art as well as open problems and research gaps. Specifically, we discuss sub-problems such as affordance detection, categorization, segmentation and high-level reasoning. Furthermore, we cover functional scene understanding and the prevalent functional descriptors used in the literature. The survey also provides necessary background to the problem, sheds light on its significance and highlights the existing challenges for affordance and functionality learning.
Tasks Scene Understanding
Published 2018-07-18
URL http://arxiv.org/abs/1807.06775v1
PDF http://arxiv.org/pdf/1807.06775v1.pdf
PWC https://paperswithcode.com/paper/visual-affordance-and-function-understanding
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Unsupervised shape transformer for image translation and cross-domain retrieval

Title Unsupervised shape transformer for image translation and cross-domain retrieval
Authors Kaili Wang, Liqian Ma, Jose Oramas, Luc Van Gool, Tinne Tuytelaars
Abstract We address the problem of unsupervised geometric image-to-image translation. Rather than transferring the style of an image as a whole, our goal is to translate the geometry of an object as depicted in different domains while preserving its appearance characteristics. Our model is trained in an unsupervised fashion, i.e. without the need of paired images during training. It performs all steps of the shape transfer within a single model and without additional post-processing stages. Extensive experiments on the VITON, CMU-Multi-PIE and our own FashionStyle datasets show the effectiveness of the method. In addition, we show that despite their low-dimensionality, the features learned by our model are useful to the item retrieval task.
Tasks Image-to-Image Translation
Published 2018-12-05
URL http://arxiv.org/abs/1812.02134v2
PDF http://arxiv.org/pdf/1812.02134v2.pdf
PWC https://paperswithcode.com/paper/integrated-unpaired-appearance-preserving
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Differentiable Dynamic Programming for Structured Prediction and Attention

Title Differentiable Dynamic Programming for Structured Prediction and Attention
Authors Arthur Mensch, Mathieu Blondel
Abstract Dynamic programming (DP) solves a variety of structured combinatorial problems by iteratively breaking them down into smaller subproblems. In spite of their versatility, DP algorithms are usually non-differentiable, which hampers their use as a layer in neural networks trained by backpropagation. To address this issue, we propose to smooth the max operator in the dynamic programming recursion, using a strongly convex regularizer. This allows to relax both the optimal value and solution of the original combinatorial problem, and turns a broad class of DP algorithms into differentiable operators. Theoretically, we provide a new probabilistic perspective on backpropagating through these DP operators, and relate them to inference in graphical models. We derive two particular instantiations of our framework, a smoothed Viterbi algorithm for sequence prediction and a smoothed DTW algorithm for time-series alignment. We showcase these instantiations on two structured prediction tasks and on structured and sparse attention for neural machine translation.
Tasks Machine Translation, Structured Prediction, Time Series, Time Series Alignment
Published 2018-02-11
URL http://arxiv.org/abs/1802.03676v2
PDF http://arxiv.org/pdf/1802.03676v2.pdf
PWC https://paperswithcode.com/paper/differentiable-dynamic-programming-for
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Grounding the Semantics of Part-of-Day Nouns Worldwide using Twitter

Title Grounding the Semantics of Part-of-Day Nouns Worldwide using Twitter
Authors David Vilares, Carlos Gómez-Rodríguez
Abstract The usage of part-of-day nouns, such as ‘night’, and their time-specific greetings (‘good night’), varies across languages and cultures. We show the possibilities that Twitter offers for studying the semantics of these terms and its variability between countries. We mine a worldwide sample of multilingual tweets with temporal greetings, and study how their frequencies vary in relation with local time. The results provide insights into the semantics of these temporal expressions and the cultural and sociological factors influencing their usage.
Tasks
Published 2018-05-23
URL http://arxiv.org/abs/1805.09055v1
PDF http://arxiv.org/pdf/1805.09055v1.pdf
PWC https://paperswithcode.com/paper/grounding-the-semantics-of-part-of-day-nouns
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Multivariate Time-series Similarity Assessment via Unsupervised Representation Learning and Stratified Locality Sensitive Hashing: Application to Early Acute Hypotensive Episode Detection

Title Multivariate Time-series Similarity Assessment via Unsupervised Representation Learning and Stratified Locality Sensitive Hashing: Application to Early Acute Hypotensive Episode Detection
Authors Jwala Dhamala, Emmanuel Azuh, Abdullah Al-Dujaili, Jonathan Rubin, Una-May O’Reilly
Abstract Timely prediction of clinically critical events in Intensive Care Unit (ICU) is important for improving care and survival rate. Most of the existing approaches are based on the application of various classification methods on explicitly extracted statistical features from vital signals. In this work, we propose to eliminate the high cost of engineering hand-crafted features from multivariate time-series of physiologic signals by learning their representation with a sequence-to-sequence auto-encoder. We then propose to hash the learned representations to enable signal similarity assessment for the prediction of critical events. We apply this methodological framework to predict Acute Hypotensive Episodes (AHE) on a large and diverse dataset of vital signal recordings. Experiments demonstrate the ability of the presented framework in accurately predicting an upcoming AHE.
Tasks Representation Learning, Time Series, Unsupervised Representation Learning
Published 2018-11-14
URL http://arxiv.org/abs/1811.06106v3
PDF http://arxiv.org/pdf/1811.06106v3.pdf
PWC https://paperswithcode.com/paper/multivariate-time-series-similarity
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Adversarial Unsupervised Representation Learning for Activity Time-Series

Title Adversarial Unsupervised Representation Learning for Activity Time-Series
Authors Karan Aggarwal, Shafiq Joty, Luis Fernandez-Luque, Jaideep Srivastava
Abstract Sufficient physical activity and restful sleep play a major role in the prevention and cure of many chronic conditions. Being able to proactively screen and monitor such chronic conditions would be a big step forward for overall health. The rapid increase in the popularity of wearable devices provides a significant new source, making it possible to track the user’s lifestyle real-time. In this paper, we propose a novel unsupervised representation learning technique called activity2vec that learns and “summarizes” the discrete-valued activity time-series. It learns the representations with three components: (i) the co-occurrence and magnitude of the activity levels in a time-segment, (ii) neighboring context of the time-segment, and (iii) promoting subject-invariance with adversarial training. We evaluate our method on four disorder prediction tasks using linear classifiers. Empirical evaluation demonstrates that our proposed method scales and performs better than many strong baselines. The adversarial regime helps improve the generalizability of our representations by promoting subject invariant features. We also show that using the representations at the level of a day works the best since human activity is structured in terms of daily routines
Tasks Representation Learning, Time Series, Unsupervised Representation Learning
Published 2018-11-14
URL http://arxiv.org/abs/1811.06847v1
PDF http://arxiv.org/pdf/1811.06847v1.pdf
PWC https://paperswithcode.com/paper/adversarial-unsupervised-representation
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Instance Search via Instance Level Segmentation and Feature Representation

Title Instance Search via Instance Level Segmentation and Feature Representation
Authors Yu Zhan, Wan-Lei Zhao
Abstract Instance search is an interesting task as well as a challenging issue due to the lack of effective feature representation. In this paper, an instance level feature representation built upon fully convolutional instance-aware segmentation is proposed. The feature is ROI-pooled from the segmented instance region. So that instances in various sizes and layouts are represented by deep features in uniform length. This representation is further enhanced by the use of deformable ResNeXt blocks. Superior performance is observed in terms of its distinctiveness and scalability on a challenging evaluation dataset built by ourselves. In addition, the proposed enhancement on the network structure also shows superior performance on the instance segmentation task.
Tasks Instance Search, Instance Segmentation, Semantic Segmentation
Published 2018-06-10
URL https://arxiv.org/abs/1806.03576v2
PDF https://arxiv.org/pdf/1806.03576v2.pdf
PWC https://paperswithcode.com/paper/instance-search-via-instance-level
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A Report on the Complex Word Identification Shared Task 2018

Title A Report on the Complex Word Identification Shared Task 2018
Authors Seid Muhie Yimam, Chris Biemann, Shervin Malmasi, Gustavo H. Paetzold, Lucia Specia, Sanja Štajner, Anaïs Tack, Marcos Zampieri
Abstract We report the findings of the second Complex Word Identification (CWI) shared task organized as part of the BEA workshop co-located with NAACL-HLT’2018. The second CWI shared task featured multilingual and multi-genre datasets divided into four tracks: English monolingual, German monolingual, Spanish monolingual, and a multilingual track with a French test set, and two tasks: binary classification and probabilistic classification. A total of 12 teams submitted their results in different task/track combinations and 11 of them wrote system description papers that are referred to in this report and appear in the BEA workshop proceedings.
Tasks Complex Word Identification
Published 2018-04-24
URL http://arxiv.org/abs/1804.09132v1
PDF http://arxiv.org/pdf/1804.09132v1.pdf
PWC https://paperswithcode.com/paper/a-report-on-the-complex-word-identification
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Modeling outcomes of soccer matches

Title Modeling outcomes of soccer matches
Authors Alkeos Tsokos, Santhosh Narayanan, Ioannis Kosmidis, Gianluca Baio, Mihai Cucuringu, Gavin Whitaker, Franz J. Király
Abstract We compare various extensions of the Bradley-Terry model and a hierarchical Poisson log-linear model in terms of their performance in predicting the outcome of soccer matches (win, draw, or loss). The parameters of the Bradley-Terry extensions are estimated by maximizing the log-likelihood, or an appropriately penalized version of it, while the posterior densities of the parameters of the hierarchical Poisson log-linear model are approximated using integrated nested Laplace approximations. The prediction performance of the various modeling approaches is assessed using a novel, context-specific framework for temporal validation that is found to deliver accurate estimates of the test error. The direct modeling of outcomes via the various Bradley-Terry extensions and the modeling of match scores using the hierarchical Poisson log-linear model demonstrate similar behavior in terms of predictive performance.
Tasks
Published 2018-07-04
URL http://arxiv.org/abs/1807.01623v2
PDF http://arxiv.org/pdf/1807.01623v2.pdf
PWC https://paperswithcode.com/paper/modeling-outcomes-of-soccer-matches
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Attentive Semantic Alignment with Offset-Aware Correlation Kernels

Title Attentive Semantic Alignment with Offset-Aware Correlation Kernels
Authors Paul Hongsuck Seo, Jongmin Lee, Deunsol Jung, Bohyung Han, Minsu Cho
Abstract Semantic correspondence is the problem of establishing correspondences across images depicting different instances of the same object or scene class. One of recent approaches to this problem is to estimate parameters of a global transformation model that densely aligns one image to the other. Since an entire correlation map between all feature pairs across images is typically used to predict such a global transformation, noisy features from different backgrounds, clutter, and occlusion distract the predictor from correct estimation of the alignment. This is a challenging issue, in particular, in the problem of semantic correspondence where a large degree of image variations is often involved. In this paper, we introduce an attentive semantic alignment method that focuses on reliable correlations, filtering out distractors. For effective attention, we also propose an offset-aware correlation kernel that learns to capture translation-invariant local transformations in computing correlation values over spatial locations. Experiments demonstrate the effectiveness of the attentive model and offset-aware kernel, and the proposed model combining both techniques achieves the state-of-the-art performance.
Tasks
Published 2018-08-06
URL http://arxiv.org/abs/1808.02128v2
PDF http://arxiv.org/pdf/1808.02128v2.pdf
PWC https://paperswithcode.com/paper/attentive-semantic-alignment-with-offset
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