January 24, 2020

2616 words 13 mins read

Paper Group NANR 246

Paper Group NANR 246

Exploring and Enhancing the Transferability of Adversarial Examples. Deep Learning 3D Shapes Using Alt-az Anisotropic 2-Sphere Convolution. DelibGAN: Coarse-to-Fine Text Generation via Adversarial Network. Improving Neural Entity Disambiguation with Graph Embeddings. Semantics and Homothetic Clustering of Hafez Poetry. Selective Convolutional Units …

Exploring and Enhancing the Transferability of Adversarial Examples

Title Exploring and Enhancing the Transferability of Adversarial Examples
Authors Lei Wu, Zhanxing Zhu, Cheng Tai
Abstract State-of-the-art deep neural networks are vulnerable to adversarial examples, formed by applying small but malicious perturbations to the original inputs. Moreover, the perturbations can \textit{transfer across models}: adversarial examples generated for a specific model will often mislead other unseen models. Consequently the adversary can leverage it to attack deployed systems without any query, which severely hinders the application of deep learning, especially in the safety-critical areas. In this work, we empirically study how two classes of factors those might influence the transferability of adversarial examples. One is about model-specific factors, including network architecture, model capacity and test accuracy. The other is the local smoothness of loss surface for constructing adversarial examples. Inspired by these understandings on the transferability of adversarial examples, we then propose a simple but effective strategy to enhance the transferability, whose effectiveness is confirmed by a variety of experiments on both CIFAR-10 and ImageNet datasets.
Tasks
Published 2019-05-01
URL https://openreview.net/forum?id=HyMRUiC9YX
PDF https://openreview.net/pdf?id=HyMRUiC9YX
PWC https://paperswithcode.com/paper/exploring-and-enhancing-the-transferability
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Deep Learning 3D Shapes Using Alt-az Anisotropic 2-Sphere Convolution

Title Deep Learning 3D Shapes Using Alt-az Anisotropic 2-Sphere Convolution
Authors Min Liu, Fupin Yao, Chiho Choi, Sinha Ayan, Karthik Ramani
Abstract The ground-breaking performance obtained by deep convolutional neural networks (CNNs) for image processing tasks is inspiring research efforts attempting to extend it for 3D geometric tasks. One of the main challenge in applying CNNs to 3D shape analysis is how to define a natural convolution operator on non-euclidean surfaces. In this paper, we present a method for applying deep learning to 3D surfaces using their spherical descriptors and alt-az anisotropic convolution on 2-sphere. A cascade set of geodesic disk filters rotate on the 2-sphere and collect spherical patterns and so to extract geometric features for various 3D shape analysis tasks. We demonstrate theoretically and experimentally that our proposed method has the possibility to bridge the gap between 2D images and 3D shapes with the desired rotation equivariance/invariance, and its effectiveness is evaluated in applications of non-rigid/ rigid shape classification and shape retrieval.
Tasks 3D Shape Analysis
Published 2019-05-01
URL https://openreview.net/forum?id=rkeSiiA5Fm
PDF https://openreview.net/pdf?id=rkeSiiA5Fm
PWC https://paperswithcode.com/paper/deep-learning-3d-shapes-using-alt-az
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DelibGAN: Coarse-to-Fine Text Generation via Adversarial Network

Title DelibGAN: Coarse-to-Fine Text Generation via Adversarial Network
Authors Ke Wang, Xiaojun Wan
Abstract In this paper, we propose a novel adversarial learning framework, namely DelibGAN, for generating high-quality sentences without supervision. Our framework consists of a coarse-to-fine generator, which contains a first-pass decoder and a second-pass decoder, and a multiple instance discriminator. And we propose two training mechanisms DelibGAN-I and DelibGAN-II. The discriminator is used to fine-tune the second-pass decoder in DelibGAN-I and further evaluate the importance of each word and tune the first-pass decoder in DelibGAN-II. We compare our models with several typical and state-of-the-art unsupervised generic text generation models on three datasets (a synthetic dataset, a descriptive text dataset and a sentimental text dataset). Both qualitative and quantitative experimental results show that our models produce more realistic samples, and DelibGAN-II performs best.
Tasks Text Generation
Published 2019-05-01
URL https://openreview.net/forum?id=SkMx_iC9K7
PDF https://openreview.net/pdf?id=SkMx_iC9K7
PWC https://paperswithcode.com/paper/delibgan-coarse-to-fine-text-generation-via
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Improving Neural Entity Disambiguation with Graph Embeddings

Title Improving Neural Entity Disambiguation with Graph Embeddings
Authors {"O}zge Sevgili, Alex Panchenko, er, Chris Biemann
Abstract Entity Disambiguation (ED) is the task of linking an ambiguous entity mention to a corresponding entry in a knowledge base. Current methods have mostly focused on unstructured text data to learn representations of entities, however, there is structured information in the knowledge base itself that should be useful to disambiguate entities. In this work, we propose a method that uses graph embeddings for integrating structured information from the knowledge base with unstructured information from text-based representations. Our experiments confirm that graph embeddings trained on a graph of hyperlinks between Wikipedia articles improve the performances of simple feed-forward neural ED model and a state-of-the-art neural ED system.
Tasks Entity Disambiguation
Published 2019-07-01
URL https://www.aclweb.org/anthology/P19-2044/
PDF https://www.aclweb.org/anthology/P19-2044
PWC https://paperswithcode.com/paper/improving-neural-entity-disambiguation-with
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Semantics and Homothetic Clustering of Hafez Poetry

Title Semantics and Homothetic Clustering of Hafez Poetry
Authors Arya Rahgozar, Diana Inkpen
Abstract We have created two sets of labels for Hafez (1315-1390) poems, using unsupervised learning. Our labels are the only semantic clustering alternative to the previously existing, hand-labeled, gold-standard classification of Hafez poems, to be used for literary research. We have cross-referenced, measured and analyzed the agreements of our clustering labels with Houman{'}s chronological classes. Our features are based on topic modeling and word embeddings. We also introduced a similarity of similarities{'} features, we called homothetic clustering approach that proved effective, in case of Hafez{'}s small corpus of ghazals2. Although all our experiments showed different clusters when compared with Houman{'}s classes, we think they were valid in their own right to have provided further insights, and have proved useful as a contrasting alternative to Houman{'}s classes. Our homothetic clusterer and its feature design and engineering framework can be used for further semantic analysis of Hafez{'}s poetry and other similar literary research.
Tasks Word Embeddings
Published 2019-06-01
URL https://www.aclweb.org/anthology/W19-2511/
PDF https://www.aclweb.org/anthology/W19-2511
PWC https://paperswithcode.com/paper/semantics-and-homothetic-clustering-of-hafez
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Selective Convolutional Units: Improving CNNs via Channel Selectivity

Title Selective Convolutional Units: Improving CNNs via Channel Selectivity
Authors Jongheon Jeong, Jinwoo Shin
Abstract Bottleneck structures with identity (e.g., residual) connection are now emerging popular paradigms for designing deep convolutional neural networks (CNN), for processing large-scale features efficiently. In this paper, we focus on the information-preserving nature of identity connection and utilize this to enable a convolutional layer to have a new functionality of channel-selectivity, i.e., re-distributing its computations to important channels. In particular, we propose Selective Convolutional Unit (SCU), a widely-applicable architectural unit that improves parameter efficiency of various modern CNNs with bottlenecks. During training, SCU gradually learns the channel-selectivity on-the-fly via the alternative usage of (a) pruning unimportant channels, and (b) rewiring the pruned parameters to important channels. The rewired parameters emphasize the target channel in a way that selectively enlarges the convolutional kernels corresponding to it. Our experimental results demonstrate that the SCU-based models without any postprocessing generally achieve both model compression and accuracy improvement compared to the baselines, consistently for all tested architectures.
Tasks Model Compression
Published 2019-05-01
URL https://openreview.net/forum?id=SJlt6oA9Fm
PDF https://openreview.net/pdf?id=SJlt6oA9Fm
PWC https://paperswithcode.com/paper/selective-convolutional-units-improving-cnns
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Exploring Adequacy Errors in Neural Machine Translation with the Help of Cross-Language Aligned Word Embeddings

Title Exploring Adequacy Errors in Neural Machine Translation with the Help of Cross-Language Aligned Word Embeddings
Authors Michael Ustaszewski
Abstract Neural machine translation (NMT) was shown to produce more fluent output than phrase-based statistical (PBMT) and rule-based machine translation (RBMT). However, improved fluency makes it more difficult for post editors to identify and correct adequacy errors, because unlike RBMT and SMT, in NMT adequacy errors are frequently not anticipated by fluency errors. Omissions and additions of content in otherwise flawlessly fluent NMT output are the most prominent types of such adequacy errors, which can only be detected with reference to source texts. This contribution explores the degree of semantic similarity between source texts, NMT output and post edited output. In this way, computational semantic similarity scores (cosine similarity) are related to human quality judgments. The analyses are based on publicly available NMT post editing data annotated for errors in three language pairs (EN-DE, EN-LV, EN-HR) with the Multidimensional Quality Metrics (MQM). Methodologically, this contribution tests whether cross-language aligned word embeddings as the sole source of semantic information mirror human error annotation.
Tasks Machine Translation, Semantic Similarity, Semantic Textual Similarity, Word Embeddings
Published 2019-09-01
URL https://www.aclweb.org/anthology/W19-8715/
PDF https://www.aclweb.org/anthology/W19-8715
PWC https://paperswithcode.com/paper/exploring-adequacy-errors-in-neural-machine
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JCTICOL at SemEval-2019 Task 6: Classifying Offensive Language in Social Media using Deep Learning Methods, Word/Character N-gram Features, and Preprocessing Methods

Title JCTICOL at SemEval-2019 Task 6: Classifying Offensive Language in Social Media using Deep Learning Methods, Word/Character N-gram Features, and Preprocessing Methods
Authors Yaakov HaCohen-Kerner, Ziv Ben-David, Gal Didi, Eli Cahn, Shalom Rochman, Elyashiv Shayovitz
Abstract In this paper, we describe our submissions to SemEval-2019 task 6 contest. We tackled all three sub-tasks in this task {``}OffensEval - Identifying and Categorizing Offensive Language in Social Media{''}. In our system called JCTICOL (Jerusalem College of Technology Identifies and Categorizes Offensive Language), we applied various supervised ML methods. We applied various combinations of word/character n-gram features using the TF-IDF scheme. In addition, we applied various combinations of seven basic preprocessing methods. Our best submission, an RNN model was ranked at the 25th position out of 65 submissions for the most complex sub-task (C). |
Tasks
Published 2019-06-01
URL https://www.aclweb.org/anthology/S19-2115/
PDF https://www.aclweb.org/anthology/S19-2115
PWC https://paperswithcode.com/paper/jcticol-at-semeval-2019-task-6-classifying
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Physiological Signal Embeddings (PHASE) via Interpretable Stacked Models

Title Physiological Signal Embeddings (PHASE) via Interpretable Stacked Models
Authors Hugh Chen, Scott Lundberg, Gabe Erion, Su-In Lee
Abstract In health, machine learning is increasingly common, yet neural network embedding (representation) learning is arguably under-utilized for physiological signals. This inadequacy stands out in stark contrast to more traditional computer science domains, such as computer vision (CV), and natural language processing (NLP). For physiological signals, learning feature embeddings is a natural solution to data insufficiency caused by patient privacy concerns – rather than share data, researchers may share informative embedding models (i.e., representation models), which map patient data to an output embedding. Here, we present the PHASE (PHysiologicAl Signal Embeddings) framework, which consists of three components: i) learning neural network embeddings of physiological signals, ii) predicting outcomes based on the learned embedding, and iii) interpreting the prediction results by estimating feature attributions in the “stacked” models (i.e., feature embedding model followed by prediction model). PHASE is novel in three ways: 1) To our knowledge, PHASE is the first instance of transferal of neural networks to create physiological signal embeddings. 2) We present a tractable method to obtain feature attributions through stacked models. We prove that our stacked model attributions can approximate Shapley values – attributions known to have desirable properties – for arbitrary sets of models. 3) PHASE was extensively tested in a cross-hospital setting including publicly available data. In our experiments, we show that PHASE significantly outperforms alternative embeddings – such as raw, exponential moving average/variance, and autoencoder – currently in use. Furthermore, we provide evidence that transferring neural network embedding/representation learners between distinct hospitals still yields performant embeddings and offer recommendations when transference is ineffective.
Tasks Network Embedding, Representation Learning
Published 2019-05-01
URL https://openreview.net/forum?id=SygInj05Fm
PDF https://openreview.net/pdf?id=SygInj05Fm
PWC https://paperswithcode.com/paper/physiological-signal-embeddings-phase-via
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Leveraging BERT to Improve the FEARS Index for Stock Forecasting

Title Leveraging BERT to Improve the FEARS Index for Stock Forecasting
Authors Linyi Yang, Ruihai Dong, Tin Lok James Ng, Yang Xu
Abstract
Tasks
Published 2019-08-01
URL https://www.aclweb.org/anthology/W19-5509/
PDF https://www.aclweb.org/anthology/W19-5509
PWC https://paperswithcode.com/paper/leveraging-bert-to-improve-the-fears-index
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Learning Unsupervised Learning Rules

Title Learning Unsupervised Learning Rules
Authors Luke Metz, Niru Maheswaranathan, Brian Cheung, Jascha Sohl-Dickstein
Abstract A major goal of unsupervised learning is to discover data representations that are useful for subsequent tasks, without access to supervised labels during training. Typically, this goal is approached by minimizing a surrogate objective, such as the negative log likelihood of a generative model, with the hope that representations useful for subsequent tasks will arise incidentally. In this work, we propose instead to directly target a later desired task by meta-learning an unsupervised learning rule, which leads to representations useful for that task. Here, our desired task (meta-objective) is the performance of the representation on semi-supervised classification, and we meta-learn an algorithm – an unsupervised weight update rule – that produces representations that perform well under this meta-objective. Additionally, we constrain our unsupervised update rule to a be a biologically-motivated, neuron-local function, which enables it to generalize to novel neural network architectures. We show that the meta-learned update rule produces useful features and sometimes outperforms existing unsupervised learning techniques. We further show that the meta-learned unsupervised update rule generalizes to train networks with different widths, depths, and nonlinearities. It also generalizes to train on data with randomly permuted input dimensions and even generalizes from image datasets to a text task.
Tasks Meta-Learning
Published 2019-05-01
URL https://openreview.net/forum?id=HkNDsiC9KQ
PDF https://openreview.net/pdf?id=HkNDsiC9KQ
PWC https://paperswithcode.com/paper/learning-unsupervised-learning-rules
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ShieldNets: Defending Against Adversarial Attacks Using Probabilistic Adversarial Robustness

Title ShieldNets: Defending Against Adversarial Attacks Using Probabilistic Adversarial Robustness
Authors Rajkumar Theagarajan, Ming Chen, Bir Bhanu, Jing Zhang
Abstract Defending adversarial attack is a critical step towards reliable deployment of deep learning empowered solutions for industrial applications. Probabilistic adversarial robustness (PAR), as a theoretical framework, is introduced to neutralize adversarial attacks by concentrating sample probability to adversarial-free zones. Distinct to most of the existing defense mechanisms that require modifying the architecture/training of the target classifier which is not feasible in the real-world scenario, e.g., when a model has already been deployed, PAR is designed in the first place to provide proactive protection to an existing fixed model. ShieldNet is implemented as a demonstration of PAR in this work by using PixelCNN. Experimental results show that this approach is generalizable, robust against adversarial transferability and resistant to a wide variety of attacks on the Fashion-MNIST and CIFAR10 datasets, respectively.
Tasks Adversarial Attack
Published 2019-06-01
URL http://openaccess.thecvf.com/content_CVPR_2019/html/Theagarajan_ShieldNets_Defending_Against_Adversarial_Attacks_Using_Probabilistic_Adversarial_Robustness_CVPR_2019_paper.html
PDF http://openaccess.thecvf.com/content_CVPR_2019/papers/Theagarajan_ShieldNets_Defending_Against_Adversarial_Attacks_Using_Probabilistic_Adversarial_Robustness_CVPR_2019_paper.pdf
PWC https://paperswithcode.com/paper/shieldnets-defending-against-adversarial
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Improving Knowledge Base Construction from Robust Infobox Extraction

Title Improving Knowledge Base Construction from Robust Infobox Extraction
Authors Boya Peng, Yejin Huh, Xiao Ling, Michele Banko
Abstract A capable, automatic Question Answering (QA) system can provide more complete and accurate answers using a comprehensive knowledge base (KB). One important approach to constructing a comprehensive knowledge base is to extract information from Wikipedia infobox tables to populate an existing KB. Despite previous successes in the Infobox Extraction (IBE) problem (e.g., DBpedia), three major challenges remain: 1) Deterministic extraction patterns used in DBpedia are vulnerable to template changes; 2) Over-trusting Wikipedia anchor links can lead to entity disambiguation errors; 3) Heuristic-based extraction of unlinkable entities yields low precision, hurting both accuracy and completeness of the final KB. This paper presents a robust approach that tackles all three challenges. We build probabilistic models to predict relations between entity mentions directly from the infobox tables in HTML. The entity mentions are linked to identifiers in an existing KB if possible. The unlinkable ones are also parsed and preserved in the final output. Training data for both the relation extraction and the entity linking models are automatically generated using distant supervision. We demonstrate the empirical effectiveness of the proposed method in both precision and recall compared to a strong IBE baseline, DBpedia, with an absolute improvement of 41.3{%} in average F1. We also show that our extraction makes the final KB significantly more complete, improving the completeness score of list-value relation types by 61.4{%}.
Tasks Entity Disambiguation, Entity Linking, Question Answering, Relation Extraction
Published 2019-06-01
URL https://www.aclweb.org/anthology/N19-2018/
PDF https://www.aclweb.org/anthology/N19-2018
PWC https://paperswithcode.com/paper/improving-knowledge-base-construction-from
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TDBot at SemEval-2019 Task 3: Context Aware Emotion Detection Using A Conditioned Classification Approach

Title TDBot at SemEval-2019 Task 3: Context Aware Emotion Detection Using A Conditioned Classification Approach
Authors Sourabh Maity
Abstract With the system description it is shown how to use the context information while detecting the emotion in a dialogue. Some guidelines about how to handle emojis was also laid out. While developing this system I realized the importance of pre-processing in conversational text data, or in general NLP related tasks; it can not be over emphasized.
Tasks
Published 2019-06-01
URL https://www.aclweb.org/anthology/S19-2058/
PDF https://www.aclweb.org/anthology/S19-2058
PWC https://paperswithcode.com/paper/tdbot-at-semeval-2019-task-3-context-aware
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Proceedings of the 3rd Workshop on Evaluating Vector Space Representations for NLP

Title Proceedings of the 3rd Workshop on Evaluating Vector Space Representations for NLP
Authors
Abstract
Tasks
Published 2019-06-01
URL https://www.aclweb.org/anthology/W19-2000/
PDF https://www.aclweb.org/anthology/W19-2000
PWC https://paperswithcode.com/paper/proceedings-of-the-3rd-workshop-on-evaluating
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