Asif Ekbal


2021

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Unknown Intent Detection using Multi-Objective Optimization on Deep Learning Classifiers
Prerna Prem | Zishan Ahmad | Asif Ekbal | Shubhashis Sengupta | Sakshi Jain | Roshini Rammani
Proceedings of the 35th Pacific Asia Conference on Language, Information and Computation

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Experiences of Adapting Multimodal Machine Translation Techniques for Hindi
Baban Gain | Dibyanayan Bandyopadhyay | Asif Ekbal
Proceedings of the First Workshop on Multimodal Machine Translation for Low Resource Languages (MMTLRL 2021)

Multimodal Neural Machine Translation (MNMT) is an interesting task in natural language processing (NLP) where we use visual modalities along with a source sentence to aid the source to target translation process. Recently, there has been a lot of works in MNMT frameworks to boost the performance of standalone Machine Translation tasks. Most of the prior works in MNMT tried to perform translation between two widely known languages (e.g. English-to-German, English-to-French ). In this paper, We explore the effectiveness of different state-of-the-art MNMT methods, which use various data oriented techniques including multimodal pre-training, for low resource languages. Although the existing methods works well on high resource languages, usability of those methods on low-resource languages is unknown. In this paper, we evaluate the existing methods on Hindi and report our findings.

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Modelling Context Emotions using Multi-task Learning for Emotion Controlled Dialog Generation
Deeksha Varshney | Asif Ekbal | Pushpak Bhattacharyya
Proceedings of the 16th Conference of the European Chapter of the Association for Computational Linguistics: Main Volume

A recent topic of research in natural language generation has been the development of automatic response generation modules that can automatically respond to a user’s utterance in an empathetic manner. Previous research has tackled this task using neural generative methods by augmenting emotion classes with the input sequences. However, the outputs by these models may be inconsistent. We employ multi-task learning to predict the emotion label and to generate a viable response for a given utterance using a common encoder with multiple decoders. Our proposed encoder-decoder model consists of a self-attention based encoder and a decoder with dot product attention mechanism to generate response with a specified emotion. We use the focal loss to handle imbalanced data distribution, and utilize the consistency loss to allow coherent decoding by the decoders. Human evaluation reveals that our model produces more emotionally pertinent responses. In addition, our model outperforms multiple strong baselines on automatic evaluation measures such as F1 and BLEU scores, thus resulting in more fluent and adequate responses.

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Unknown Intent Detection Using Multi-Objective Optimization on Deep Learning Classifiers
Prerna Prem | Zishan Ahmad | Asif Ekbal | Shubhashis Sengupta | Sakshi C. Jain | Roshni Ramnani
Proceedings of the International Conference on Recent Advances in Natural Language Processing (RANLP 2021)

Modelling and understanding dialogues in a conversation depends on identifying the user intent from the given text. Unknown or new intent detection is a critical task, as in a realistic scenario a user intent may frequently change over time and divert even to an intent previously not encountered. This task of separating the unknown intent samples from known intents one is challenging as the unknown user intent can range from intents similar to the predefined intents to something completely different. Prior research on intent discovery often consider it as a classification task where an unknown intent can belong to a predefined set of known intent classes. In this paper we tackle the problem of detecting a completely unknown intent without any prior hints about the kind of classes belonging to unknown intents. We propose an effective post-processing method using multi-objective optimization to tune an existing neural network based intent classifier and make it capable of detecting unknown intents. We perform experiments using existing state-of-the-art intent classifiers and use our method on top of them for unknown intent detection. Our experiments across different domains and real-world datasets show that our method yields significant improvements compared with the state-of-the-art methods for unknown intent detection.

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Towards Developing a Multilingual and Code-Mixed Visual Question Answering System by Knowledge Distillation
Humair Raj Khan | Deepak Gupta | Asif Ekbal
Findings of the Association for Computational Linguistics: EMNLP 2021

Pre-trained language-vision models have shown remarkable performance on the visual question answering (VQA) task. However, most pre-trained models are trained by only considering monolingual learning, especially the resource-rich language like English. Training such models for multilingual setups demand high computing resources and multilingual language-vision dataset which hinders their application in practice. To alleviate these challenges, we propose a knowledge distillation approach to extend an English language-vision model (teacher) into an equally effective multilingual and code-mixed model (student). Unlike the existing knowledge distillation methods, which only use the output from the last layer of the teacher network for distillation, our student model learns and imitates the teacher from multiple intermediate layers (language and vision encoders) with appropriately designed distillation objectives for incremental knowledge extraction. We also create the large-scale multilingual and code-mixed VQA dataset in eleven different language setups considering the multiple Indian and European languages. Experimental results and in-depth analysis show the effectiveness of the proposed VQA model over the pre-trained language-vision models on eleven diverse language setups.

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IITP at WAT 2021: System description for English-Hindi Multimodal Translation Task
Baban Gain | Dibyanayan Bandyopadhyay | Asif Ekbal
Proceedings of the 8th Workshop on Asian Translation (WAT2021)

Neural Machine Translation (NMT) is a predominant machine translation technology nowadays because of its end-to-end trainable flexibility. However, NMT still struggles to translate properly in low-resource settings specifically on distant language pairs. One way to overcome this is to use the information from other modalities if available. The idea is that despite differences in languages, both the source and target language speakers see the same thing and the visual representation of both the source and target is the same, which can positively assist the system. Multimodal information can help the NMT system to improve the translation by removing ambiguity on some phrases or words. We participate in the 8th Workshop on Asian Translation (WAT - 2021) for English-Hindi multimodal translation task and achieve 42.47 and 37.50 BLEU points for Evaluation and Challenge subset, respectively.

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IITP-MT at WAT2021: Indic-English Multilingual Neural Machine Translation using Romanized Vocabulary
Ramakrishna Appicharla | Kamal Kumar Gupta | Asif Ekbal | Pushpak Bhattacharyya
Proceedings of the 8th Workshop on Asian Translation (WAT2021)

This paper describes the systems submitted to WAT 2021 MultiIndicMT shared task by IITP-MT team. We submit two multilingual Neural Machine Translation (NMT) systems (Indic-to-English and English-to-Indic). We romanize all Indic data and create subword vocabulary which is shared between all Indic languages. We use back-translation approach to generate synthetic data which is appended to parallel corpus and used to train our models. The models are evaluated using BLEU, RIBES and AMFM scores with Indic-to-English model achieving 40.08 BLEU for Hindi-English pair and English-to-Indic model achieving 34.48 BLEU for English-Hindi pair. However, we observe that the shared romanized subword vocabulary is not helping English-to-Indic model at the time of generation, leading it to produce poor quality translations for Tamil, Telugu and Malayalam to English pairs with BLEU score of 8.51, 6.25 and 3.79 respectively.

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Investigating Active Learning in Interactive Neural Machine Translation
Kamal Gupta | Dhanvanth Boppana | Rejwanul Haque | Asif Ekbal | Pushpak Bhattacharyya
Proceedings of Machine Translation Summit XVIII: Research Track

Interactive-predictive translation is a collaborative iterative process and where human translators produce translations with the help of machine translation (MT) systems interactively. Various sampling techniques in active learning (AL) exist to update the neural MT (NMT) model in the interactive-predictive scenario. In this paper and we explore term based (named entity count (NEC)) and quality based (quality estimation (QE) and sentence similarity (Sim)) sampling techniques – which are used to find the ideal candidates from the incoming data – for human supervision and MT model’s weight updation. We carried out experiments with three language pairs and viz. German-English and Spanish-English and Hindi-English. Our proposed sampling technique yields 1.82 and 0.77 and 0.81 BLEU points improvements for German-English and Spanish-English and Hindi-English and respectively and over random sampling based baseline. It also improves the present state-of-the-art by 0.35 and 0.12 BLEU points for German-English and Spanish-English and respectively. Human editing effort in terms of number-of-words-changed also improves by 5 and 4 points for German-English and Spanish-English and respectively and compared to the state-of-the-art.

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Sentiment Preservation in Review Translation using Curriculum-based Re-inforcement Framework
Divya Kumari | Soumya Chennabasavaraj | Nikesh Garera | Asif Ekbal
Proceedings of Machine Translation Summit XVIII: Research Track

Machine Translation (MT) systems often fail to preserve different stylistic and pragmatic properties of the source text (e.g. sentiment and emotion and gender traits and etc.) to the target and especially in a low-resource scenario. Such loss can affect the performance of any downstream Natural Language Processing (NLP) task and such as sentiment analysis and that heavily relies on the output of the MT systems. The susceptibility to sentiment polarity loss becomes even more severe when an MT system is employed for translating a source content that lacks a legitimate language structure (e.g. review text). Therefore and we must find ways to minimize the undesirable effects of sentiment loss in translation without compromising with the adequacy. In our current work and we present a deep re-inforcement learning (RL) framework in conjunction with the curriculum learning (as per difficulties of the reward) to fine-tune the parameters of a pre-trained neural MT system so that the generated translation successfully encodes the underlying sentiment of the source without compromising the adequacy unlike previous methods. We evaluate our proposed method on the English–Hindi (product domain) and French–English (restaurant domain) review datasets and and found that our method brings a significant improvement over several baselines in the machine translation and and sentiment classification tasks.

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Product Review Translation using Phrase Replacement and Attention Guided Noise Augmentation
Kamal Gupta | Soumya Chennabasavaraj | Nikesh Garera | Asif Ekbal
Proceedings of Machine Translation Summit XVIII: Research Track

Product reviews provide valuable feedback of the customers and however and they are available today only in English on most of the e-commerce platforms. The nature of reviews provided by customers in any multilingual country poses unique challenges for machine translation such as code-mixing and ungrammatical sentences and presence of colloquial terms and lack of e-commerce parallel corpus etc. Given that 44% of Indian population speaks and operates in Hindi language and we address the above challenges by presenting an English–to–Hindi neural machine translation (NMT) system to translate the product reviews available on e-commerce websites by creating an in-domain parallel corpora and handling various types of noise in reviews via two data augmentation techniques and viz. (i). a novel phrase augmentation technique (PhrRep) where the syntactic noun phrases in sentences are replaced by the other noun phrases carrying different meanings but in similar context; and (ii). a novel attention guided noise augmentation (AttnNoise) technique to make our NMT model robust towards various noise. Evaluation shows that using the proposed augmentation techniques we achieve a 6.67 BLEU score improvement over the baseline model. In order to show that our proposed approach is not language-specific and we also perform experiments for two other language pairs and viz. En-Fr (MTNT18 corpus) and En-De (IWSLT17) that yield the improvements of 2.55 and 0.91 BLEU points and respectively and over the baselines.

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IITP-MT at CALCS2021: English to Hinglish Neural Machine Translation using Unsupervised Synthetic Code-Mixed Parallel Corpus
Ramakrishna Appicharla | Kamal Kumar Gupta | Asif Ekbal | Pushpak Bhattacharyya
Proceedings of the Fifth Workshop on Computational Approaches to Linguistic Code-Switching

This paper describes the system submitted by IITP-MT team to Computational Approaches to Linguistic Code-Switching (CALCS 2021) shared task on MT for English→Hinglish. We submit a neural machine translation (NMT) system which is trained on the synthetic code-mixed (cm) English-Hinglish parallel corpus. We propose an approach to create code-mixed parallel corpus from a clean parallel corpus in an unsupervised manner. It is an alignment based approach and we do not use any linguistic resources for explicitly marking any token for code-switching. We also train NMT model on the gold corpus provided by the workshop organizers augmented with the generated synthetic code-mixed parallel corpus. The model trained over the generated synthetic cm data achieves 10.09 BLEU points over the given test set.

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Product Review Translation: Parallel Corpus Creation and Robustness towards User-generated Noisy Text
Kamal Kumar Gupta | Soumya Chennabasavaraj | Nikesh Garera | Asif Ekbal
Proceedings of The 4th Workshop on e-Commerce and NLP

Reviews written by the users for a particular product or service play an influencing role for the customers to make an informative decision. Although online e-commerce portals have immensely impacted our lives, available contents predominantly are in English language- often limiting its widespread usage. There is an exponential growth in the number of e-commerce users who are not proficient in English. Hence, there is a necessity to make these services available in non-English languages, especially in a multilingual country like India. This can be achieved by an in-domain robust machine translation (MT) system. However, the reviews written by the users pose unique challenges to MT, such as misspelled words, ungrammatical constructions, presence of colloquial terms, lack of resources such as in-domain parallel corpus etc. We address the above challenges by presenting an English–Hindi review domain parallel corpus. We train an English–to–Hindi neural machine translation (NMT) system to translate the product reviews available on e-commerce websites. By training the Transformer based NMT model over the generated data, we achieve a score of 33.26 BLEU points for English–to–Hindi translation. In order to make our NMT model robust enough to handle the noisy tokens in the reviews, we integrate a character based language model to generate word vectors and map the noisy tokens with their correct forms. Experiments on four language pairs, viz. English-Hindi, English-German, English-French, and English-Czech show the BLUE scores of 35.09, 28.91, 34.68 and 14.52 which are the improvements of 1.61, 1.05, 1.63 and 1.94, respectively, over the baseline.

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SEPRG: Sentiment aware Emotion controlled Personalized Response Generation
Mauajama Firdaus | Umang Jain | Asif Ekbal | Pushpak Bhattacharyya
Proceedings of the 14th International Conference on Natural Language Generation

Social chatbots have gained immense popularity, and their appeal lies not just in their capacity to respond to the diverse requests from users, but also in the ability to develop an emotional connection with users. To further develop and promote social chatbots, we need to concentrate on increasing user interaction and take into account both the intellectual and emotional quotient in the conversational agents. Therefore, in this work, we propose the task of sentiment aware emotion controlled personalized dialogue generation giving the machine the capability to respond emotionally and in accordance with the persona of the user. As sentiment and emotions are highly co-related, we use the sentiment knowledge of the previous utterance to generate the correct emotional response in accordance with the user persona. We design a Transformer based Dialogue Generation framework, that generates responses that are sensitive to the emotion of the user and corresponds to the persona and sentiment as well. Moreover, the persona information is encoded by a different Transformer encoder, along with the dialogue history, is fed to the decoder for generating responses. We annotate the PersonaChat dataset with sentiment information to improve the response quality. Experimental results on the PersonaChat dataset show that the proposed framework significantly outperforms the existing baselines, thereby generating personalized emotional responses in accordance with the sentiment that provides better emotional connection and user satisfaction as desired in a social chatbot.

2020

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All-in-One: A Deep Attentive Multi-task Learning Framework for Humour, Sarcasm, Offensive, Motivation, and Sentiment on Memes
Dushyant Singh Chauhan | Dhanush S R | Asif Ekbal | Pushpak Bhattacharyya
Proceedings of the 1st Conference of the Asia-Pacific Chapter of the Association for Computational Linguistics and the 10th International Joint Conference on Natural Language Processing

In this paper, we aim at learning the relationships and similarities of a variety of tasks, such as humour detection, sarcasm detection, offensive content detection, motivational content detection and sentiment analysis on a somewhat complicated form of information, i.e., memes. We propose a multi-task, multi-modal deep learning framework to solve multiple tasks simultaneously. For multi-tasking, we propose two attention-like mechanisms viz., Inter-task Relationship Module (iTRM) and Inter-class Relationship Module (iCRM). The main motivation of iTRM is to learn the relationship between the tasks to realize how they help each other. In contrast, iCRM develops relations between the different classes of tasks. Finally, representations from both the attentions are concatenated and shared across the five tasks (i.e., humour, sarcasm, offensive, motivational, and sentiment) for multi-tasking. We use the recently released dataset in the Memotion Analysis task @ SemEval 2020, which consists of memes annotated for the classes as mentioned above. Empirical results on Memotion dataset show the efficacy of our proposed approach over the existing state-of-the-art systems (Baseline and SemEval 2020 winner). The evaluation also indicates that the proposed multi-task framework yields better performance over the single-task learning.

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Unsupervised Aspect-Level Sentiment Controllable Style Transfer
Mukuntha Narayanan Sundararaman | Zishan Ahmad | Asif Ekbal | Pushpak Bhattacharyya
Proceedings of the 1st Conference of the Asia-Pacific Chapter of the Association for Computational Linguistics and the 10th International Joint Conference on Natural Language Processing

Unsupervised style transfer in text has previously been explored through the sentiment transfer task. The task entails inverting the overall sentiment polarity in a given input sentence, while preserving its content. From the Aspect-Based Sentiment Analysis (ABSA) task, we know that multiple sentiment polarities can often be present together in a sentence with multiple aspects. In this paper, the task of aspect-level sentiment controllable style transfer is introduced, where each of the aspect-level sentiments can individually be controlled at the output. To achieve this goal, a BERT-based encoder-decoder architecture with saliency weighted polarity injection is proposed, with unsupervised training strategies, such as ABSA masked-language-modelling. Through both automatic and manual evaluation, we show that the system is successful in controlling aspect-level sentiments.

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A Unified Framework for Multilingual and Code-Mixed Visual Question Answering
Deepak Gupta | Pabitra Lenka | Asif Ekbal | Pushpak Bhattacharyya
Proceedings of the 1st Conference of the Asia-Pacific Chapter of the Association for Computational Linguistics and the 10th International Joint Conference on Natural Language Processing

In this paper, we propose an effective deep learning framework for multilingual and code- mixed visual question answering. The pro- posed model is capable of predicting answers from the questions in Hindi, English or Code- mixed (Hinglish: Hindi-English) languages. The majority of the existing techniques on Vi- sual Question Answering (VQA) focus on En- glish questions only. However, many applica- tions such as medical imaging, tourism, visual assistants require a multilinguality-enabled module for their widespread usages. As there is no available dataset in English-Hindi VQA, we firstly create Hindi and Code-mixed VQA datasets by exploiting the linguistic properties of these languages. We propose a robust tech- nique capable of handling the multilingual and code-mixed question to provide the answer against the visual information (image). To better encode the multilingual and code-mixed questions, we introduce a hierarchy of shared layers. We control the behaviour of these shared layers by an attention-based soft layer sharing mechanism, which learns how shared layers are applied in different ways for the dif- ferent languages of the question. Further, our model uses bi-linear attention with a residual connection to fuse the language and image fea- tures. We perform extensive evaluation and ablation studies for English, Hindi and Code- mixed VQA. The evaluation shows that the proposed multilingual model achieves state-of- the-art performance in all these settings.

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Only text? only image? or both? Predicting sentiment of internet memes
Pranati Behera | Mamta . | Asif Ekbal
Proceedings of the 17th International Conference on Natural Language Processing (ICON)

Nowadays, the spread of Internet memes on online social media platforms such as Instagram, Facebook, Reddit, and Twitter is very fast. Analyzing the sentiment of memes can provide various useful insights. Meme sentiment classification is a new area of research that is not explored yet. Recently SemEval provides a dataset for meme sentiment classification. As this dataset is highly imbalanced, we extend this dataset by annotating new instances and use a sampling strategy to build a meme sentiment classifier. We propose a multi-modal framework for meme sentiment classification by utilizing textual and visual features of the meme. We found that for meme sentiment classification, only textual or only visual features are not sufficient. Our proposed framework utilizes textual as well as visual features together. We propose to use the attention mechanism to improve meme classification performance. Our proposed framework achieves macro F1 and accuracy of 34.23 and 50.02, respectively. It increases the accuracy by 6.77 and 7.86 compared to only textual and visual features, respectively.

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Annotated Corpus of Tweets in English from Various Domains for Emotion Detection
Soumitra Ghosh | Asif Ekbal | Pushpak Bhattacharyya | Sriparna Saha | Vipin Tyagi | Alka Kumar | Shikha Srivastava | Nitish Kumar
Proceedings of the 17th International Conference on Natural Language Processing (ICON)

Emotion recognition is a very well-attended problem in Natural Language Processing (NLP). Most of the existing works on emotion recognition focus on the general domain and in some cases to specific domains like fairy tales, blogs, weather, Twitter etc. But emotion analysis systems in the domains of security, social issues, technology, politics, sports, etc. are very rare. In this paper, we create a benchmark setup for emotion recognition in these specialised domains. First, we construct a corpus of 18,921 tweets in English annotated with Paul Ekman’s six basic emotions (Anger, Disgust, Fear, Happiness, Sadness, Surprise) and a non-emotive class Others. Thereafter, we propose a deep neural framework to perform emotion recognition in an end-to-end setting. We build various models based on Convolutional Neural Network (CNN), Bi-directional Long Short Term Memory (Bi-LSTM), Bi-directional Gated Recurrent Unit (Bi-GRU). We propose a Hierarchical Attention-based deep neural network for Emotion Detection (HAtED). We also develop multiple systems by considering different sets of emotion classes for each system and report the detailed comparative analysis of the results. Experiments show the hierarchical attention-based model achieves best results among the considered baselines with accuracy of 69%.

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Leveraging Multi-domain, Heterogeneous Data using Deep Multitask Learning for Hate Speech Detection
Prashant Kapil | Asif Ekbal
Proceedings of the 17th International Conference on Natural Language Processing (ICON)

With the exponential rise in user-generated web content on social media, the proliferation of abusive languages towards an individual or a group across the different sections of the internet is also rapidly increasing. It is very challenging for human moderators to identify the offensive contents and filter those out. Deep neural networks have shown promise with reasonable accuracy for hate speech detection and allied applications. However, the classifiers are heavily dependent on the size and quality of the training data. Such a high-quality large data set is not easy to obtain. Moreover, the existing data sets that have emerged in recent times are not created following the same annotation guidelines and are often concerned with different types and sub-types related to hate. To solve this data sparsity problem, and to obtain more global representative features, we propose a Convolution Neural Network (CNN) based multi-task learning models (MTLs) to leverage information from multiple sources. Empirical analysis performed on three benchmark datasets shows the efficacy of the proposed approach with the significant improvement in accuracy and F-score to obtain state-of-the-art performance with respect to the existing systems.

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Proceedings of the 17th International Conference on Natural Language Processing (ICON): TechDOfication 2020 Shared Task
Dipti Misra Sharma | Asif Ekbal | Karunesh Arora | Sudip Kumar Naskar | Dipankar Ganguly | Sobha L | Radhika Mamidi | Sunita Arora | Pruthwik Mishra | Vandan Mujadia
Proceedings of the 17th International Conference on Natural Language Processing (ICON): TechDOfication 2020 Shared Task

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Proceedings of the 17th International Conference on Natural Language Processing (ICON): TermTraction 2020 Shared Task
Dipti Misra Sharma | Asif Ekbal | Karunesh Arora | Sudip Kumar Naskar | Dipankar Ganguly | Sobha L | Radhika Mamidi | Sunita Arora | Pruthwik Mishra | Vandan Mujadia
Proceedings of the 17th International Conference on Natural Language Processing (ICON): TermTraction 2020 Shared Task

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Proceedings of the 17th International Conference on Natural Language Processing (ICON): Adap-MT 2020 Shared Task
Dipti Misra Sharma | Asif Ekbal | Karunesh Arora | Sudip Kumar Naskar | Dipankar Ganguly | Sobha L | Radhika Mamidi | Sunita Arora | Pruthwik Mishra | Vandan Mujadia
Proceedings of the 17th International Conference on Natural Language Processing (ICON): Adap-MT 2020 Shared Task

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Proceedings of the 17th International Conference on Natural Language Processing (ICON): System Demonstrations
Vishal Goyal | Asif Ekbal
Proceedings of the 17th International Conference on Natural Language Processing (ICON): System Demonstrations

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Modelling Source- and Target- Language Syntactic Information as Conditional Context in Interactive Neural Machine Translation
Kamal Kumar Gupta | Rejwanul Haque | Asif Ekbal | Pushpak Bhattacharyya | Andy Way
Proceedings of the 22nd Annual Conference of the European Association for Machine Translation

In interactive machine translation (MT), human translators correct errors in automatic translations in collaboration with the MT systems, which is seen as an effective way to improve the productivity gain in translation. In this study, we model source-language syntactic constituency parse and target-language syntactic descriptions in the form of supertags as conditional context for interactive prediction in neural MT (NMT). We found that the supertags significantly improve productivity gain in translation in interactive-predictive NMT (INMT), while syntactic parsing somewhat found to be effective in reducing human effort in translation. Furthermore, when we model this source- and target-language syntactic information together as the conditional context, both types complement each other and our fully syntax-informed INMT model statistically significantly reduces human efforts in a French–to–English translation task, achieving 4.30 points absolute (corresponding to 9.18% relative) improvement in terms of word prediction accuracy (WPA) and 4.84 points absolute (corresponding to 9.01% relative) reduction in terms of word stroke ratio (WSR) over the baseline.

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IITP-AINLPML at SemEval-2020 Task 12: Offensive Tweet Identification and Target Categorization in a Multitask Environment
Soumitra Ghosh | Asif Ekbal | Pushpak Bhattacharyya
Proceedings of the Fourteenth Workshop on Semantic Evaluation

In this paper, we describe the participation of IITP-AINLPML team in the SemEval-2020 SharedTask 12 on Offensive Language Identification and Target Categorization in English Twitter data. Our proposed model learns to extract textual features using a BiGRU-based deep neural network supported by a Hierarchical Attention architecture to focus on the most relevant areas in the text. We leverage the effectiveness of multitask learning while building our models for sub-task A and B. We do necessary undersampling of the over-represented classes in the sub-tasks A and C.During training, we consider a threshold of 0.5 as the separation margin between the instances belonging to classes OFF and NOT in sub-task A and UNT and TIN in sub-task B. For sub-task C, the class corresponding to the maximum score among the given confidence scores of the classes(IND, GRP and OTH) is considered as the final label for an instance. Our proposed model obtains the macro F1-scores of 90.95%, 55.69% and 63.88% in sub-task A, B and C, respectively.

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A Semi-supervised Approach to Generate the Code-Mixed Text using Pre-trained Encoder and Transfer Learning
Deepak Gupta | Asif Ekbal | Pushpak Bhattacharyya
Findings of the Association for Computational Linguistics: EMNLP 2020

Code-mixing, the interleaving of two or more languages within a sentence or discourse is ubiquitous in multilingual societies. The lack of code-mixed training data is one of the major concerns for the development of end-to-end neural network-based models to be deployed for a variety of natural language processing (NLP) applications. A potential solution is to either manually create or crowd-source the code-mixed labelled data for the task at hand, but that requires much human efforts and often not feasible because of the language specific diversity in the code-mixed text. To circumvent the data scarcity issue, we propose an effective deep learning approach for automatically generating the code-mixed text from English to multiple languages without any parallel data. In order to train the neural network, we create synthetic code-mixed texts from the available parallel corpus by modelling various linguistic properties of code-mixing. Our codemixed text generator is built upon the encoder-decoder framework, where the encoder is augmented with the linguistic and task-agnostic features obtained from the transformer based language model. We also transfer the knowledge from a neural machine translation (NMT) to warm-start the training of code-mixed generator. Experimental results and in-depth analysis show the effectiveness of our proposed code-mixed text generation on eight diverse language pairs.

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MultiDM-GCN: Aspect-guided Response Generation in Multi-domain Multi-modal Dialogue System using Graph Convolutional Network
Mauajama Firdaus | Nidhi Thakur | Asif Ekbal
Findings of the Association for Computational Linguistics: EMNLP 2020

In the recent past, dialogue systems have gained immense popularity and have become ubiquitous. During conversations, humans not only rely on languages but seek contextual information through visual contents as well. In every task-oriented dialogue system, the user is guided by the different aspects of a product or service that regulates the conversation towards selecting the product or service. In this work, we present a multi-modal conversational framework for a task-oriented dialogue setup that generates the responses following the different aspects of a product or service to cater to the user’s needs. We show that the responses guided by the aspect information provide more interactive and informative responses for better communication between the agent and the user. We first create a Multi-domain Multi-modal Dialogue (MDMMD) dataset having conversations involving both text and images belonging to the three different domains, such as restaurants, electronics, and furniture. We implement a Graph Convolutional Network (GCN) based framework that generates appropriate textual responses from the multi-modal inputs. The multi-modal information having both textual and image representation is fed to the decoder and the aspect information for generating aspect guided responses. Quantitative and qualitative analyses show that the proposed methodology outperforms several baselines for the proposed task of aspect-guided response generation.

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Reinforced Multi-task Approach for Multi-hop Question Generation
Deepak Gupta | Hardik Chauhan | Ravi Tej Akella | Asif Ekbal | Pushpak Bhattacharyya
Proceedings of the 28th International Conference on Computational Linguistics

Question generation (QG) attempts to solve the inverse of question answering (QA) problem by generating a natural language question given a document and an answer. While sequence to sequence neural models surpass rule-based systems for QG, they are limited in their capacity to focus on more than one supporting fact. For QG, we often require multiple supporting facts to generate high-quality questions. Inspired by recent works on multi-hop reasoning in QA, we take up Multi-hop question generation, which aims at generating relevant questions based on supporting facts in the context. We employ multitask learning with the auxiliary task of answer-aware supporting fact prediction to guide the question generator. In addition, we also proposed a question-aware reward function in a Reinforcement Learning (RL) framework to maximize the utilization of the supporting facts. We demonstrate the effectiveness of our approach through experiments on the multi-hop question answering dataset, HotPotQA. Empirical evaluation shows our model to outperform the single-hop neural question generation models on both automatic evaluation metrics such as BLEU, METEOR, and ROUGE and human evaluation metrics for quality and coverage of the generated questions.

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MEISD: A Multimodal Multi-Label Emotion, Intensity and Sentiment Dialogue Dataset for Emotion Recognition and Sentiment Analysis in Conversations
Mauajama Firdaus | Hardik Chauhan | Asif Ekbal | Pushpak Bhattacharyya
Proceedings of the 28th International Conference on Computational Linguistics

Emotion and sentiment classification in dialogues is a challenging task that has gained popularity in recent times. Humans tend to have multiple emotions with varying intensities while expressing their thoughts and feelings. Emotions in an utterance of dialogue can either be independent or dependent on the previous utterances, thus making the task complex and interesting. Multi-label emotion detection in conversations is a significant task that provides the ability to the system to understand the various emotions of the users interacting. Sentiment analysis in dialogue/conversation, on the other hand, helps in understanding the perspective of the user with respect to the ongoing conversation. Along with text, additional information in the form of audio and video assist in identifying the correct emotions with the appropriate intensity and sentiments in an utterance of a dialogue. Lately, quite a few datasets have been made available for dialogue emotion and sentiment classification, but these datasets are imbalanced in representing different emotions and consist of an only single emotion. Hence, we present at first a large-scale balanced Multimodal Multi-label Emotion, Intensity, and Sentiment Dialogue dataset (MEISD), collected from different TV series that has textual, audio and visual features, and then establish a baseline setup for further research.

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CEASE, a Corpus of Emotion Annotated Suicide notes in English
Soumitra Ghosh | Asif Ekbal | Pushpak Bhattacharyya
Proceedings of the 12th Language Resources and Evaluation Conference

A suicide note is usually written shortly before the suicide and it provides a chance to comprehend the self-destructive state of mind of the deceased. From a psychological point of view, suicide notes have been utilized for recognizing the motive behind the suicide. To the best of our knowledge, there is no openly accessible suicide note corpus at present, making it challenging for the researchers and developers to deep dive into the area of mental health assessment and suicide prevention. In this paper, we create a fine-grained emotion annotated corpus (CEASE) of suicide notes in English and develop various deep learning models to perform emotion detection on the curated dataset. The corpus consists of 2393 sentences from around 205 suicide notes collected from various sources. Each sentence is annotated with a particular emotion class from a set of 15 fine-grained emotion labels, namely (forgiveness, happiness_peacefulness, love, pride, hopefulness, thankfulness, blame, anger, fear, abuse, sorrow, hopelessness, guilt, information, instructions). For the evaluation, we develop an ensemble architecture, where the base models correspond to three supervised deep learning models, namely Convolutional Neural Network (CNN), Gated Recurrent Unit (GRU) and Long Short Term Memory (LSTM). We obtain the highest test accuracy of 60.17% and cross-validation accuracy of 60.32%

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A Platform for Event Extraction in Hindi
Sovan Kumar Sahoo | Saumajit Saha | Asif Ekbal | Pushpak Bhattacharyya
Proceedings of the 12th Language Resources and Evaluation Conference

Event Extraction is an important task in the widespread field of Natural Language Processing (NLP). Though this task is adequately addressed in English with sufficient resources, we are unaware of any benchmark setup in Indian languages. Hindi is one of the most widely spoken languages in the world. In this paper, we present an Event Extraction framework for Hindi language by creating an annotated resource for benchmarking, and then developing deep learning based models to set as the baselines. We crawl more than seventeen hundred disaster related Hindi news articles from the various news sources. We also develop deep learning based models for Event Trigger Detection and Classification, Argument Detection and Classification and Event-Argument Linking.

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Incorporating Politeness across Languages in Customer Care Responses: Towards building a Multi-lingual Empathetic Dialogue Agent
Mauajama Firdaus | Asif Ekbal | Pushpak Bhattacharyya
Proceedings of the 12th Language Resources and Evaluation Conference

Customer satisfaction is an essential aspect of customer care systems. It is imperative for such systems to be polite while handling customer requests/demands. In this paper, we present a large multi-lingual conversational dataset for English and Hindi. We choose data from Twitter having both generic and courteous responses between customer care agents and aggrieved users. We also propose strong baselines that can induce courteous behaviour in generic customer care response in a multi-lingual scenario. We build a deep learning framework that can simultaneously handle different languages and incorporate polite behaviour in the customer care agent’s responses. Our system is competent in generating responses in different languages (here, English and Hindi) depending on the customer’s preference and also is able to converse with humans in an empathetic manner to ensure customer satisfaction and retention. Experimental results show that our proposed models can converse in both the languages and the information shared between the languages helps in improving the performance of the overall system. Qualitative and quantitative analysis shows that the proposed method can converse in an empathetic manner by incorporating courteousness in the responses and hence increasing customer satisfaction.

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Multi-domain Tweet Corpora for Sentiment Analysis: Resource Creation and Evaluation
Mamta . | Asif Ekbal | Pushpak Bhattacharyya | Shikha Srivastava | Alka Kumar | Tista Saha
Proceedings of the 12th Language Resources and Evaluation Conference

Due to the phenomenal growth of online content in recent time, sentiment analysis has attracted attention of the researchers and developers. A number of benchmark annotated corpora are available for domains like movie reviews, product reviews, hotel reviews, etc.The pervasiveness of social media has also lead to a huge amount of content posted by users who are misusing the power of social media to spread false beliefs and to negatively influence others. This type of content is coming from the domains like terrorism, cybersecurity, technology, social issues, etc. Mining of opinions from these domains is important to create a socially intelligent system to provide security to the public and to maintain the law and order situations. To the best of our knowledge, there is no publicly available tweet corpora for such pervasive domains. Hence, we firstly create a multi-domain tweet sentiment corpora and then establish a deep neural network based baseline framework to address the above mentioned issues. Annotated corpus has Cohen’s Kappa measurement for annotation quality of 0.770, which shows that the data is of acceptable quality. We are able to achieve 84.65% accuracy for sentiment analysis by using an ensemble of Convolutional Neural Network (CNN), Long Short Term Memory (LSTM), and Gated Recurrent Unit(GRU).

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ScholarlyRead: A New Dataset for Scientific Article Reading Comprehension
Tanik Saikh | Asif Ekbal | Pushpak Bhattacharyya
Proceedings of the 12th Language Resources and Evaluation Conference

We present ScholarlyRead, span-of-word-based scholarly articles’ Reading Comprehension (RC) dataset with approximately 10K manually checked passage-question-answer instances. ScholarlyRead was constructed in semi-automatic way. We consider the articles from two popular journals of a reputed publishing house. Firstly, we generate questions from these articles in an automatic way. Generated questions are then manually checked by the human annotators. We propose a baseline model based on Bi-Directional Attention Flow (BiDAF) network that yields the F1 score of 37.31%. The framework would be useful for building Question-Answering (QA) systems on scientific articles.

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Sentiment and Emotion help Sarcasm? A Multi-task Learning Framework for Multi-Modal Sarcasm, Sentiment and Emotion Analysis
Dushyant Singh Chauhan | Dhanush S R | Asif Ekbal | Pushpak Bhattacharyya
Proceedings of the 58th Annual Meeting of the Association for Computational Linguistics

In this paper, we hypothesize that sarcasm is closely related to sentiment and emotion, and thereby propose a multi-task deep learning framework to solve all these three problems simultaneously in a multi-modal conversational scenario. We, at first, manually annotate the recently released multi-modal MUStARD sarcasm dataset with sentiment and emotion classes, both implicit and explicit. For multi-tasking, we propose two attention mechanisms, viz. Inter-segment Inter-modal Attention (Ie-Attention) and Intra-segment Inter-modal Attention (Ia-Attention). The main motivation of Ie-Attention is to learn the relationship between the different segments of the sentence across the modalities. In contrast, Ia-Attention focuses within the same segment of the sentence across the modalities. Finally, representations from both the attentions are concatenated and shared across the five classes (i.e., sarcasm, implicit sentiment, explicit sentiment, implicit emotion, explicit emotion) for multi-tasking. Experimental results on the extended version of the MUStARD dataset show the efficacy of our proposed approach for sarcasm detection over the existing state-of-the-art systems. The evaluation also shows that the proposed multi-task framework yields better performance for the primary task, i.e., sarcasm detection, with the help of two secondary tasks, emotion and sentiment analysis.

2019

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DeepSentiPeer: Harnessing Sentiment in Review Texts to Recommend Peer Review Decisions
Tirthankar Ghosal | Rajeev Verma | Asif Ekbal | Pushpak Bhattacharyya
Proceedings of the 57th Annual Meeting of the Association for Computational Linguistics

Automatically validating a research artefact is one of the frontiers in Artificial Intelligence (AI) that directly brings it close to competing with human intellect and intuition. Although criticised sometimes, the existing peer review system still stands as the benchmark of research validation. The present-day peer review process is not straightforward and demands profound domain knowledge, expertise, and intelligence of human reviewer(s), which is somewhat elusive with the current state of AI. However, the peer review texts, which contains rich sentiment information of the reviewer, reflecting his/her overall attitude towards the research in the paper, could be a valuable entity to predict the acceptance or rejection of the manuscript under consideration. Here in this work, we investigate the role of reviewer sentiment embedded within peer review texts to predict the peer review outcome. Our proposed deep neural architecture takes into account three channels of information: the paper, the corresponding reviews, and review’s polarity to predict the overall recommendation score as well as the final decision. We achieve significant performance improvement over the baselines (∼ 29% error reduction) proposed in a recently released dataset of peer reviews. An AI of this kind could assist the editors/program chairs as an additional layer of confidence, especially when non-responding/missing reviewers are frequent in present day peer review.

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Multilingual Unsupervised NMT using Shared Encoder and Language-Specific Decoders
Sukanta Sen | Kamal Kumar Gupta | Asif Ekbal | Pushpak Bhattacharyya
Proceedings of the 57th Annual Meeting of the Association for Computational Linguistics

In this paper, we propose a multilingual unsupervised NMT scheme which jointly trains multiple languages with a shared encoder and multiple decoders. Our approach is based on denoising autoencoding of each language and back-translating between English and multiple non-English languages. This results in a universal encoder which can encode any language participating in training into an inter-lingual representation, and language-specific decoders. Our experiments using only monolingual corpora show that multilingual unsupervised model performs better than the separately trained bilingual models achieving improvement of up to 1.48 BLEU points on WMT test sets. We also observe that even if we do not train the network for all possible translation directions, the network is still able to translate in a many-to-many fashion leveraging encoder’s ability to generate interlingual representation.

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A Unified Multi-task Adversarial Learning Framework for Pharmacovigilance Mining
Shweta Yadav | Asif Ekbal | Sriparna Saha | Pushpak Bhattacharyya
Proceedings of the 57th Annual Meeting of the Association for Computational Linguistics

The mining of adverse drug reaction (ADR) has a crucial role in the pharmacovigilance. The traditional ways of identifying ADR are reliable but time-consuming, non-scalable and offer a very limited amount of ADR relevant information. With the unprecedented growth of information sources in the forms of social media texts (Twitter, Blogs, Reviews etc.), biomedical literature, and Electronic Medical Records (EMR), it has become crucial to extract the most pertinent ADR related information from these free-form texts. In this paper, we propose a neural network inspired multi- task learning framework that can simultaneously extract ADRs from various sources. We adopt a novel adversarial learning-based approach to learn features across multiple ADR information sources. Unlike the other existing techniques, our approach is capable to extracting fine-grained information (such as ‘Indications’, ‘Symptoms’, ‘Finding’, ‘Disease’, ‘Drug’) which provide important cues in pharmacovigilance. We evaluate our proposed approach on three publicly available real- world benchmark pharmacovigilance datasets, a Twitter dataset from PSB 2016 Social Me- dia Shared Task, CADEC corpus and Medline ADR corpus. Experiments show that our unified framework achieves state-of-the-art performance on individual tasks associated with the different benchmark datasets. This establishes the fact that our proposed approach is generic, which enables it to achieve high performance on the diverse datasets.

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Ordinal and Attribute Aware Response Generation in a Multimodal Dialogue System
Hardik Chauhan | Mauajama Firdaus | Asif Ekbal | Pushpak Bhattacharyya
Proceedings of the 57th Annual Meeting of the Association for Computational Linguistics

Multimodal dialogue systems have opened new frontiers in the traditional goal-oriented dialogue systems. The state-of-the-art dialogue systems are primarily based on unimodal sources, predominantly the text, and hence cannot capture the information present in the other sources such as videos, audios, images etc. With the availability of large scale multimodal dialogue dataset (MMD) (Saha et al., 2018) on the fashion domain, the visual appearance of the products is essential for understanding the intention of the user. Without capturing the information from both the text and image, the system will be incapable of generating correct and desirable responses. In this paper, we propose a novel position and attribute aware attention mechanism to learn enhanced image representation conditioned on the user utterance. Our evaluation shows that the proposed model can generate appropriate responses while preserving the position and attribute information. Experimental results also prove that our proposed approach attains superior performance compared to the baseline models, and outperforms the state-of-the-art approaches on text similarity based evaluation metrics.

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Language-Agnostic Model for Aspect-Based Sentiment Analysis
Md Shad Akhtar | Abhishek Kumar | Asif Ekbal | Chris Biemann | Pushpak Bhattacharyya
Proceedings of the 13th International Conference on Computational Semantics - Long Papers

In this paper, we propose a language-agnostic deep neural network architecture for aspect-based sentiment analysis. The proposed approach is based on Bidirectional Long Short-Term Memory (Bi-LSTM) network, which is further assisted with extra hand-crafted features. We define three different architectures for the successful combination of word embeddings and hand-crafted features. We evaluate the proposed approach for six languages (i.e. English, Spanish, French, Dutch, German and Hindi) and two problems (i.e. aspect term extraction and aspect sentiment classification). Experiments show that the proposed model attains state-of-the-art performance in most of the settings.

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IITP at MEDIQA 2019: Systems Report for Natural Language Inference, Question Entailment and Question Answering
Dibyanayan Bandyopadhyay | Baban Gain | Tanik Saikh | Asif Ekbal
Proceedings of the 18th BioNLP Workshop and Shared Task

This paper presents the experiments accomplished as a part of our participation in the MEDIQA challenge, an (Abacha et al., 2019) shared task. We participated in all the three tasks defined in this particular shared task. The tasks are viz. i. Natural Language Inference (NLI) ii. Recognizing Question Entailment(RQE) and their application in medical Question Answering (QA). We submitted runs using multiple deep learning based systems (runs) for each of these three tasks. We submitted five system results in each of the NLI and RQE tasks, and four system results for the QA task. The systems yield encouraging results in all the three tasks. The highest performance obtained in NLI, RQE and QA tasks are 81.8%, 53.2%, and 71.7%, respectively.

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IITP-MT System for Gujarati-English News Translation Task at WMT 2019
Sukanta Sen | Kamal Kumar Gupta | Asif Ekbal | Pushpak Bhattacharyya
Proceedings of the Fourth Conference on Machine Translation (Volume 2: Shared Task Papers, Day 1)

We describe our submission to WMT 2019 News translation shared task for Gujarati-English language pair. We submit constrained systems, i.e, we rely on the data provided for this language pair and do not use any external data. We train Transformer based subword-level neural machine translation (NMT) system using original parallel corpus along with synthetic parallel corpus obtained through back-translation of monolingual data. Our primary systems achieve BLEU scores of 10.4 and 8.1 for Gujarati→English and English→Gujarati, respectively. We observe that incorporating monolingual data through back-translation improves the BLEU score significantly over baseline NMT and SMT systems for this language pair.

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Parallel Corpus Filtering Based on Fuzzy String Matching
Sukanta Sen | Asif Ekbal | Pushpak Bhattacharyya
Proceedings of the Fourth Conference on Machine Translation (Volume 3: Shared Task Papers, Day 2)

In this paper, we describe the IIT Patna’s submission to WMT 2019 shared task on parallel corpus filtering. This shared task asks the participants to develop methods for scoring each parallel sentence from a given noisy parallel corpus. Quality of the scoring method is judged based on the quality of SMT and NMT systems trained on smaller set of high-quality parallel sentences sub-sampled from the original noisy corpus. This task has two language pairs. We submit for both the Nepali-English and Sinhala-English language pairs. We define fuzzy string matching score between English and the translated (into English) source based on Levenshtein distance. Based on the scores, we sub-sample two sets (having 1 million and 5 millions English tokens) of parallel sentences from each parallel corpus, and train SMT systems for development purpose only. The organizers publish the official evaluation using both SMT and NMT on the final official test set. Total 10 teams participated in the shared task and according the official evaluation, our scoring method obtains 2nd position in the team ranking for 1-million NepaliEnglish NMT and 5-million Sinhala-English NMT categories.

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Multi-task Learning for Multi-modal Emotion Recognition and Sentiment Analysis
Md Shad Akhtar | Dushyant Chauhan | Deepanway Ghosal | Soujanya Poria | Asif Ekbal | Pushpak Bhattacharyya
Proceedings of the 2019 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies, Volume 1 (Long and Short Papers)

Related tasks often have inter-dependence on each other and perform better when solved in a joint framework. In this paper, we present a deep multi-task learning framework that jointly performs sentiment and emotion analysis both. The multi-modal inputs (i.e. text, acoustic and visual frames) of a video convey diverse and distinctive information, and usually do not have equal contribution in the decision making. We propose a context-level inter-modal attention framework for simultaneously predicting the sentiment and expressed emotions of an utterance. We evaluate our proposed approach on CMU-MOSEI dataset for multi-modal sentiment and emotion analysis. Evaluation results suggest that multi-task learning framework offers improvement over the single-task framework. The proposed approach reports new state-of-the-art performance for both sentiment analysis and emotion analysis.

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Courteously Yours: Inducing courteous behavior in Customer Care responses using Reinforced Pointer Generator Network
Hitesh Golchha | Mauajama Firdaus | Asif Ekbal | Pushpak Bhattacharyya
Proceedings of the 2019 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies, Volume 1 (Long and Short Papers)

In this paper, we propose an effective deep learning framework for inducing courteous behavior in customer care responses. The interaction between a customer and the customer care representative contributes substantially to the overall customer experience. Thus it is imperative for customer care agents and chatbots engaging with humans to be personal, cordial and emphatic to ensure customer satisfaction and retention. Our system aims at automatically transforming neutral customer care responses into courteous replies. Along with stylistic transfer (of courtesy), our system ensures that responses are coherent with the conversation history, and generates courteous expressions consistent with the emotional state of the customer. Our technique is based on a reinforced pointer-generator model for the sequence to sequence task. The model is also conditioned on a hierarchically encoded and emotionally aware conversational context. We use real interactions on Twitter between customer care professionals and aggrieved customers to create a large conversational dataset having both forms of agent responses: ‘generic’ and ‘courteous’. We perform quantitative and qualitative analyses on established and task-specific metrics, both automatic and human evaluation based. Our evaluation shows that the proposed models can generate emotionally-appropriate courteous expressions while preserving the content. Experimental results also prove that our proposed approach performs better than the baseline models.

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A Deep Ensemble Framework for Fake News Detection and Multi-Class Classification of Short Political Statements
Arjun Roy | Kingshuk Basak | Asif Ekbal | Pushpak Bhattacharyya
Proceedings of the 16th International Conference on Natural Language Processing

Fake news, rumor, incorrect information, and misinformation detection are nowadays crucial issues as these might have serious consequences for our social fabrics. Such information is increasing rapidly due to the availability of enormous web information sources including social media feeds, news blogs, online newspapers etc. In this paper, we develop various deep learning models for detecting fake news and classifying them into the pre-defined fine-grained categories. At first, we develop individual models based on Convolutional Neural Network (CNN), and Bi-directional Long Short Term Memory (Bi-LSTM) networks. The representations obtained from these two models are fed into a Multi-layer Perceptron Model (MLP) for the final classification. Our experiments on a benchmark dataset show promising results with an overall accuracy of 44.87%, which outperforms the current state of the arts.

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Multi-linguality helps: Event-Argument Extraction for Disaster Domain in Cross-lingual and Multi-lingual setting
Zishan Ahmad | Deeksha Varshney | Asif Ekbal | Pushpak Bhattacharyya
Proceedings of the 16th International Conference on Natural Language Processing

Automatic extraction of disaster-related events and their arguments from natural language text is vital for building a decision support system for crisis management. Event extraction from various news sources is a well-explored area for this objective. However, extracting events alone, without any context, provides only partial help for this purpose. Extracting related arguments like Time, Place, Casualties, etc., provides a complete picture of the disaster event. In this paper, we create a disaster domain dataset in Hindi by annotating disaster-related event and arguments. We also obtain equivalent datasets for Bengali and English from a collaboration. We build a multi-lingual deep learning model for argument extraction in all the three languages. We also compare our multi-lingual system with a similar baseline mono-lingual system trained for each language separately. It is observed that a single multi-lingual system is able to compensate for lack of training data, by using joint training of dataset from different languages in shared space, thus giving a better overall result.

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A Multi-task Model for Multilingual Trigger Detection and Classification
Sovan Kumar Sahoo | Saumajit Saha | Asif Ekbal | Pushpak Bhattacharyya
Proceedings of the 16th International Conference on Natural Language Processing

In this paper we present a deep multi-task learning framework for multilingual event and argument trigger detection and classification. In our current work, we identify detection and classification of both event and argument triggers as related tasks and follow a multi-tasking approach to solve them simultaneously in contrast to the previous works where these tasks were solved separately or learning some of the above mentioned tasks jointly. We evaluate the proposed approach with multiple low-resource Indian languages. As there were no datasets available for the Indian languages, we have annotated disaster related news data crawled from the online news portal for different low-resource Indian languages for our experiments. Our empirical evaluation shows that multi-task model performs better than the single task model, and classification helps in trigger detection and vice-versa.

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A Deep Learning Approach for Automatic Detection of Fake News
Tanik Saikh | Arkadipta De | Asif Ekbal | Pushpak Bhattacharyya
Proceedings of the 16th International Conference on Natural Language Processing

Fake news detection is a very prominent and essential task in the field of journalism. This challenging problem is seen so far in the field of politics, but it could be even more challenging when it is to be determined in the multi-domain platform. In this paper, we propose two effective models based on deep learning for solving fake news detection problem in online news contents of multiple domains. We evaluate our techniques on the two recently released datasets, namely Fake News AMT and Celebrity for fake news detection. The proposed systems yield encouraging performance, outperforming the current hand-crafted feature engineering based state-of-the-art system with a significant margin of 3.08% and 9.3% by the two models, respectively. In order to exploit the datasets, available for the related tasks, we perform cross-domain analysis (model trained on FakeNews AMT and tested on Celebrity and vice versa) to explore the applicability of our systems across the domains.

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NLP at SemEval-2019 Task 6: Detecting Offensive language using Neural Networks
Prashant Kapil | Asif Ekbal | Dipankar Das
Proceedings of the 13th International Workshop on Semantic Evaluation

In this paper we built several deep learning architectures to participate in shared task OffensEval: Identifying and categorizing Offensive language in Social media by semEval-2019. The dataset was annotated with three level annotation schemes and task was to detect between offensive and not offensive, categorization and target identification in offensive contents. Deep learning models with POS information as feature were also leveraged for classification. The three best models that performed best on individual sub tasks are stacking of CNN-Bi-LSTM with Attention, BiLSTM with POS information added with word features and Bi-LSTM for third task. Our models achieved a Macro F1 score of 0.7594, 0.5378 and 0.4588 in Task(A,B,C) respectively with rank of 33rd, 54th and 52nd out of 103, 75 and 65 submissions.The three best models that performed best on individual sub task are using Neural Networks.

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Context-aware Interactive Attention for Multi-modal Sentiment and Emotion Analysis
Dushyant Singh Chauhan | Md Shad Akhtar | Asif Ekbal | Pushpak Bhattacharyya
Proceedings of the 2019 Conference on Empirical Methods in Natural Language Processing and the 9th International Joint Conference on Natural Language Processing (EMNLP-IJCNLP)

In recent times, multi-modal analysis has been an emerging and highly sought-after field at the intersection of natural language processing, computer vision, and speech processing. The prime objective of such studies is to leverage the diversified information, (e.g., textual, acoustic and visual), for learning a model. The effective interaction among these modalities often leads to a better system in terms of performance. In this paper, we introduce a recurrent neural network based approach for the multi-modal sentiment and emotion analysis. The proposed model learns the inter-modal interaction among the participating modalities through an auto-encoder mechanism. We employ a context-aware attention module to exploit the correspondence among the neighboring utterances. We evaluate our proposed approach for five standard multi-modal affect analysis datasets. Experimental results suggest the efficacy of the proposed model for both sentiment and emotion analysis over various existing state-of-the-art systems.

2018

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IARM: Inter-Aspect Relation Modeling with Memory Networks in Aspect-Based Sentiment Analysis
Navonil Majumder | Soujanya Poria | Alexander Gelbukh | Md. Shad Akhtar | Erik Cambria | Asif Ekbal
Proceedings of the 2018 Conference on Empirical Methods in Natural Language Processing

Sentiment analysis has immense implications in e-commerce through user feedback mining. Aspect-based sentiment analysis takes this one step further by enabling businesses to extract aspect specific sentimental information. In this paper, we present a novel approach of incorporating the neighboring aspects related information into the sentiment classification of the target aspect using memory networks. We show that our method outperforms the state of the art by 1.6% on average in two distinct domains: restaurant and laptop.

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Contextual Inter-modal Attention for Multi-modal Sentiment Analysis
Deepanway Ghosal | Md Shad Akhtar | Dushyant Chauhan | Soujanya Poria | Asif Ekbal | Pushpak Bhattacharyya
Proceedings of the 2018 Conference on Empirical Methods in Natural Language Processing

Multi-modal sentiment analysis offers various challenges, one being the effective combination of different input modalities, namely text, visual and acoustic. In this paper, we propose a recurrent neural network based multi-modal attention framework that leverages the contextual information for utterance-level sentiment prediction. The proposed approach applies attention on multi-modal multi-utterance representations and tries to learn the contributing features amongst them. We evaluate our proposed approach on two multi-modal sentiment analysis benchmark datasets, viz. CMU Multi-modal Opinion-level Sentiment Intensity (CMU-MOSI) corpus and the recently released CMU Multi-modal Opinion Sentiment and Emotion Intensity (CMU-MOSEI) corpus. Evaluation results show the effectiveness of our proposed approach with the accuracies of 82.31% and 79.80% for the MOSI and MOSEI datasets, respectively. These are approximately 2 and 1 points performance improvement over the state-of-the-art models for the datasets.

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Can Taxonomy Help? Improving Semantic Question Matching using Question Taxonomy
Deepak Gupta | Rajkumar Pujari | Asif Ekbal | Pushpak Bhattacharyya | Anutosh Maitra | Tom Jain | Shubhashis Sengupta
Proceedings of the 27th International Conference on Computational Linguistics

In this paper, we propose a hybrid technique for semantic question matching. It uses a proposed two-layered taxonomy for English questions by augmenting state-of-the-art deep learning models with question classes obtained from a deep learning based question classifier. Experiments performed on three open-domain datasets demonstrate the effectiveness of our proposed approach. We achieve state-of-the-art results on partial ordering question ranking (POQR) benchmark dataset. Our empirical analysis shows that coupling standard distributional features (provided by the question encoder) with knowledge from taxonomy is more effective than either deep learning or taxonomy-based knowledge alone.

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Novelty Goes Deep. A Deep Neural Solution To Document Level Novelty Detection
Tirthankar Ghosal | Vignesh Edithal | Asif Ekbal | Pushpak Bhattacharyya | George Tsatsaronis | Srinivasa Satya Sameer Kumar Chivukula
Proceedings of the 27th International Conference on Computational Linguistics

The rapid growth of documents across the web has necessitated finding means of discarding redundant documents and retaining novel ones. Capturing redundancy is challenging as it may involve investigating at a deep semantic level. Techniques for detecting such semantic redundancy at the document level are scarce. In this work we propose a deep Convolutional Neural Networks (CNN) based model to classify a document as novel or redundant with respect to a set of relevant documents already seen by the system. The system is simple and do not require any manual feature engineering. Our novel scheme encodes relevant and relative information from both source and target texts to generate an intermediate representation which we coin as the Relative Document Vector (RDV). The proposed method outperforms the existing state-of-the-art on a document-level novelty detection dataset by a margin of ∼5% in terms of accuracy. We further demonstrate the effectiveness of our approach on a standard paraphrase detection dataset where paraphrased passages closely resemble to semantically redundant documents.

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Solving Data Sparsity for Aspect Based Sentiment Analysis Using Cross-Linguality and Multi-Linguality
Md Shad Akhtar | Palaash Sawant | Sukanta Sen | Asif Ekbal | Pushpak Bhattacharyya
Proceedings of the 2018 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies, Volume 1 (Long Papers)

Efficient word representations play an important role in solving various problems related to Natural Language Processing (NLP), data mining, text mining etc. The issue of data sparsity poses a great challenge in creating efficient word representation model for solving the underlying problem. The problem is more intensified in resource-poor scenario due to the absence of sufficient amount of corpus. In this work we propose to minimize the effect of data sparsity by leveraging bilingual word embeddings learned through a parallel corpus. We train and evaluate Long Short Term Memory (LSTM) based architecture for aspect level sentiment classification. The neural network architecture is further assisted by the hand-crafted features for the prediction. We show the efficacy of the proposed model against state-of-the-art methods in two experimental setups i.e. multi-lingual and cross-lingual.

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Fine-Grained Temporal Orientation and its Relationship with Psycho-Demographic Correlates
Sabyasachi Kamila | Mohammed Hasanuzzaman | Asif Ekbal | Pushpak Bhattacharyya | Andy Way
Proceedings of the 2018 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies, Volume 1 (Long Papers)

Temporal orientation refers to an individual’s tendency to connect to the psychological concepts of past, present or future, and it affects personality, motivation, emotion, decision making and stress coping processes. The study of the social media users’ psycho-demographic attributes from the perspective of human temporal orientation can be of utmost interest and importance to the business and administrative decision makers as it can provide an extra precious information for them to make informed decisions. In this paper, we propose a very first study to demonstrate the association between the sentiment view of the temporal orientation of the users and their different psycho-demographic attributes by analyzing their tweets. We first create a temporal orientation classifier in a minimally supervised way which classifies each tweet of the users in one of the three temporal categories, namely past, present, and future. A deep Bi-directional Long Short Term Memory (BLSTM) is used for the tweet classification task. Our tweet classifier achieves an accuracy of 78.27% when tested on a manually created test set. We then determine the users’ overall temporal orientation based on their tweets on the social media. The sentiment is added to the tweets at the fine-grained level where each temporal tweet is given a sentiment with either of the positive, negative or neutral. Our experiment reveals that depending upon the sentiment view of temporal orientation, a user’s attributes vary. We finally measure the correlation between the users’ sentiment view of temporal orientation and their different psycho-demographic factors using regression.

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Multi-Task Learning Framework for Mining Crowd Intelligence towards Clinical Treatment
Shweta Yadav | Asif Ekbal | Sriparna Saha | Pushpak Bhattacharyya | Amit Sheth
Proceedings of the 2018 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies, Volume 2 (Short Papers)

In recent past, social media has emerged as an active platform in the context of healthcare and medicine. In this paper, we present a study where medical user’s opinions on health-related issues are analyzed to capture the medical sentiment at a blog level. The medical sentiments can be studied in various facets such as medical condition, treatment, and medication that characterize the overall health status of the user. Considering these facets, we treat analysis of this information as a multi-task classification problem. In this paper, we adopt a novel adversarial learning approach for our multi-task learning framework to learn the sentiment’s strengths expressed in a medical blog. Our evaluation shows promising results for our target tasks.

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An Ensemble Approach for Aggression Identification in English and Hindi Text
Arjun Roy | Prashant Kapil | Kingshuk Basak | Asif Ekbal
Proceedings of the First Workshop on Trolling, Aggression and Cyberbullying (TRAC-2018)

This paper describes our system submitted in the shared task at COLING 2018 TRAC-1: Aggression Identification. The objective of this task was to predict online aggression spread through online textual post or comment. The dataset was released in two languages, English and Hindi. We submitted a single system for Hindi and a single system for English. Both the systems are based on an ensemble architecture where the individual models are based on Convoluted Neural Network and Support Vector Machine. Evaluation shows promising results for both the languages.The total submission for English was 30 and Hindi was 15. Our system on English facebook and social media obtained F1 score of 0.5151 and 0.5099 respectively where Hindi facebook and social media obtained F1 score of 0.5599 and 0.3790 respectively.

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Uncovering Code-Mixed Challenges: A Framework for Linguistically Driven Question Generation and Neural Based Question Answering
Deepak Gupta | Pabitra Lenka | Asif Ekbal | Pushpak Bhattacharyya
Proceedings of the 22nd Conference on Computational Natural Language Learning

Existing research on question answering (QA) and comprehension reading (RC) are mainly focused on the resource-rich language like English. In recent times, the rapid growth of multi-lingual web content has posed several challenges to the existing QA systems. Code-mixing is one such challenge that makes the task more complex. In this paper, we propose a linguistically motivated technique for code-mixed question generation (CMQG) and a neural network based architecture for code-mixed question answering (CMQA). For evaluation, we manually create the code-mixed questions for Hindi-English language pair. In order to show the effectiveness of our neural network based CMQA technique, we utilize two benchmark datasets, SQuAD and MMQA. Experiments show that our proposed model achieves encouraging performance on CMQG and CMQA.

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IITP-MT at WAT2018: Transformer-based Multilingual Indic-English Neural Machine Translation System
Sukanta Sen | Kamal Kumar Gupta | Asif Ekbal | Pushpak Bhattacharyya
Proceedings of the 32nd Pacific Asia Conference on Language, Information and Computation: 5th Workshop on Asian Translation: 5th Workshop on Asian Translation

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Sentence Level Temporality Detection using an Implicit Time-sensed Resource
Sabyasachi Kamila | Asif Ekbal | Pushpak Bhattacharyya
Proceedings of the Eleventh International Conference on Language Resources and Evaluation (LREC 2018)

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A Deep Neural Network based Approach for Entity Extraction in Code-Mixed Indian Social Media Text
Deepak Gupta | Asif Ekbal | Pushpak Bhattacharyya
Proceedings of the Eleventh International Conference on Language Resources and Evaluation (LREC 2018)

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MMQA: A Multi-domain Multi-lingual Question-Answering Framework for English and Hindi
Deepak Gupta | Surabhi Kumari | Asif Ekbal | Pushpak Bhattacharyya
Proceedings of the Eleventh International Conference on Language Resources and Evaluation (LREC 2018)

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Medical Sentiment Analysis using Social Media: Towards building a Patient Assisted System
Shweta Yadav | Asif Ekbal | Sriparna Saha | Pushpak Bhattacharyya
Proceedings of the Eleventh International Conference on Language Resources and Evaluation (LREC 2018)

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TAP-DLND 1.0 : A Corpus for Document Level Novelty Detection
Tirthankar Ghosal | Amitra Salam | Swati Tiwari | Asif Ekbal | Pushpak Bhattacharyya
Proceedings of the Eleventh International Conference on Language Resources and Evaluation (LREC 2018)

2017

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A Multilayer Perceptron based Ensemble Technique for Fine-grained Financial Sentiment Analysis
Md Shad Akhtar | Abhishek Kumar | Deepanway Ghosal | Asif Ekbal | Pushpak Bhattacharyya
Proceedings of the 2017 Conference on Empirical Methods in Natural Language Processing

In this paper, we propose a novel method for combining deep learning and classical feature based models using a Multi-Layer Perceptron (MLP) network for financial sentiment analysis. We develop various deep learning models based on Convolutional Neural Network (CNN), Long Short Term Memory (LSTM) and Gated Recurrent Unit (GRU). These are trained on top of pre-trained, autoencoder-based, financial word embeddings and lexicon features. An ensemble is constructed by combining these deep learning models and a classical supervised model based on Support Vector Regression (SVR). We evaluate our proposed technique on a benchmark dataset of SemEval-2017 shared task on financial sentiment analysis. The propose model shows impressive results on two datasets, i.e. microblogs and news headlines datasets. Comparisons show that our proposed model performs better than the existing state-of-the-art systems for the above two datasets by 2.0 and 4.1 cosine points, respectively.

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IITP at IJCNLP-2017 Task 4: Auto Analysis of Customer Feedback using CNN and GRU Network
Deepak Gupta | Pabitra Lenka | Harsimran Bedi | Asif Ekbal | Pushpak Bhattacharyya
Proceedings of the IJCNLP 2017, Shared Tasks

Analyzing customer feedback is the best way to channelize the data into new marketing strategies that benefit entrepreneurs as well as customers. Therefore an automated system which can analyze the customer behavior is in great demand. Users may write feedbacks in any language, and hence mining appropriate information often becomes intractable. Especially in a traditional feature-based supervised model, it is difficult to build a generic system as one has to understand the concerned language for finding the relevant features. In order to overcome this, we propose deep Convolutional Neural Network (CNN) and Recurrent Neural Network (RNN) based approaches that do not require handcrafting of features. We evaluate these techniques for analyzing customer feedback sentences on four languages, namely English, French, Japanese and Spanish. Our empirical analysis shows that our models perform well in all the four languages on the setups of IJCNLP Shared Task on Customer Feedback Analysis. Our model achieved the second rank in French, with an accuracy of 71.75% and third ranks for all the other languages.

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Temporal Orientation of Tweets for Predicting Income of Users
Mohammed Hasanuzzaman | Sabyasachi Kamila | Mandeep Kaur | Sriparna Saha | Asif Ekbal
Proceedings of the 55th Annual Meeting of the Association for Computational Linguistics (Volume 2: Short Papers)

Automatically estimating a user’s socio-economic profile from their language use in social media can significantly help social science research and various downstream applications ranging from business to politics. The current paper presents the first study where user cognitive structure is used to build a predictive model of income. In particular, we first develop a classifier using a weakly supervised learning framework to automatically time-tag tweets as past, present, or future. We quantify a user’s overall temporal orientation based on their distribution of tweets, and use it to build a predictive model of income. Our analysis uncovers a correlation between future temporal orientation and income. Finally, we measure the predictive power of future temporal orientation on income by performing regression.

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IIT-UHH at SemEval-2017 Task 3: Exploring Multiple Features for Community Question Answering and Implicit Dialogue Identification
Titas Nandi | Chris Biemann | Seid Muhie Yimam | Deepak Gupta | Sarah Kohail | Asif Ekbal | Pushpak Bhattacharyya
Proceedings of the 11th International Workshop on Semantic Evaluation (SemEval-2017)

In this paper we present the system for Answer Selection and Ranking in Community Question Answering, which we build as part of our participation in SemEval-2017 Task 3. We develop a Support Vector Machine (SVM) based system that makes use of textual, domain-specific, word-embedding and topic-modeling features. In addition, we propose a novel method for dialogue chain identification in comment threads. Our primary submission won subtask C, outperforming other systems in all the primary evaluation metrics. We performed well in other English subtasks, ranking third in subtask A and eighth in subtask B. We also developed open source toolkits for all the three English subtasks by the name cQARank [https://github.com/TitasNandi/cQARank].

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IITP at SemEval-2017 Task 8 : A Supervised Approach for Rumour Evaluation
Vikram Singh | Sunny Narayan | Md Shad Akhtar | Asif Ekbal | Pushpak Bhattacharyya
Proceedings of the 11th International Workshop on Semantic Evaluation (SemEval-2017)

This paper describes our system participation in the SemEval-2017 Task 8 ‘RumourEval: Determining rumour veracity and support for rumours’. The objective of this task was to predict the stance and veracity of the underlying rumour. We propose a supervised classification approach employing several lexical, content and twitter specific features for learning. Evaluation shows promising results for both the problems.

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IITPB at SemEval-2017 Task 5: Sentiment Prediction in Financial Text
Abhishek Kumar | Abhishek Sethi | Md Shad Akhtar | Asif Ekbal | Chris Biemann | Pushpak Bhattacharyya
Proceedings of the 11th International Workshop on Semantic Evaluation (SemEval-2017)

This paper reports team IITPB’s participation in the SemEval 2017 Task 5 on ‘Fine-grained sentiment analysis on financial microblogs and news’. We developed 2 systems for the two tracks. One system was based on an ensemble of Support Vector Classifier and Logistic Regression. This system relied on Distributional Thesaurus (DT), word embeddings and lexicon features to predict a floating sentiment value between -1 and +1. The other system was based on Support Vector Regression using word embeddings, lexicon features, and PMI scores as features. The system was ranked 5th in track 1 and 8th in track 2.

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IITP at SemEval-2017 Task 5: An Ensemble of Deep Learning and Feature Based Models for Financial Sentiment Analysis
Deepanway Ghosal | Shobhit Bhatnagar | Md Shad Akhtar | Asif Ekbal | Pushpak Bhattacharyya
Proceedings of the 11th International Workshop on Semantic Evaluation (SemEval-2017)

In this paper we propose an ensemble based model which combines state of the art deep learning sentiment analysis algorithms like Convolution Neural Network (CNN) and Long Short Term Memory (LSTM) along with feature based models to identify optimistic or pessimistic sentiments associated with companies and stocks in financial texts. We build our system to participate in a competition organized by Semantic Evaluation 2017 International Workshop. We combined predictions from various models using an artificial neural network to determine the opinion towards an entity in (a) Microblog Messages and (b) News Headlines data. Our models achieved a cosine similarity score of 0.751 and 0.697 for the above two tracks giving us the rank of 2nd and 7th best team respectively.

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IITP at EmoInt-2017: Measuring Intensity of Emotions using Sentence Embeddings and Optimized Features
Md Shad Akhtar | Palaash Sawant | Asif Ekbal | Jyoti Pawar | Pushpak Bhattacharyya
Proceedings of the 8th Workshop on Computational Approaches to Subjectivity, Sentiment and Social Media Analysis

This paper describes the system that we submitted as part of our participation in the shared task on Emotion Intensity (EmoInt-2017). We propose a Long short term memory (LSTM) based architecture cascaded with Support Vector Regressor (SVR) for intensity prediction. We also employ Particle Swarm Optimization (PSO) based feature selection algorithm for obtaining an optimized feature set for training and evaluation. System evaluation shows interesting results on the four emotion datasets i.e. anger, fear, joy and sadness. In comparison to the other participating teams our system was ranked 5th in the competition.

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Document Level Novelty Detection: Textual Entailment Lends a Helping Hand
Tanik Saikh | Tirthankar Ghosal | Asif Ekbal | Pushpak Bhattacharyya
Proceedings of the 14th International Conference on Natural Language Processing (ICON-2017)

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Supervised Methods For Ranking Relations In Web Search
Sumit Asthana | Asif Ekbal
Proceedings of the 14th International Conference on Natural Language Processing (ICON-2017)

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Entity Extraction in Biomedical Corpora: An Approach to Evaluate Word Embedding Features with PSO based Feature Selection
Shweta Yadav | Asif Ekbal | Sriparna Saha | Pushpak Bhattacharyya
Proceedings of the 15th Conference of the European Chapter of the Association for Computational Linguistics: Volume 1, Long Papers

Text mining has drawn significant attention in recent past due to the rapid growth in biomedical and clinical records. Entity extraction is one of the fundamental components for biomedical text mining. In this paper, we propose a novel approach of feature selection for entity extraction that exploits the concept of deep learning and Particle Swarm Optimization (PSO). The system utilizes word embedding features along with several other features extracted by studying the properties of the datasets. We obtain an interesting observation that compact word embedding features as determined by PSO are more effective compared to the entire word embedding feature set for entity extraction. The proposed system is evaluated on three benchmark biomedical datasets such as GENIA, GENETAG, and AiMed. The effectiveness of the proposed approach is evident with significant performance gains over the baseline models as well as the other existing systems. We observe improvements of 7.86%, 5.27% and 7.25% F-measure points over the baseline models for GENIA, GENETAG, and AiMed dataset respectively.

2016

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Semi-supervised Clustering of Medical Text
Pracheta Sahoo | Asif Ekbal | Sriparna Saha | Diego Mollá | Kaushik Nandan
Proceedings of the Clinical Natural Language Processing Workshop (ClinicalNLP)

Semi-supervised clustering is an attractive alternative for traditional (unsupervised) clustering in targeted applications. By using the information of a small annotated dataset, semi-supervised clustering can produce clusters that are customized to the application domain. In this paper, we present a semi-supervised clustering technique based on a multi-objective evolutionary algorithm (NSGA-II-clus). We apply this technique to the task of clustering medical publications for Evidence Based Medicine (EBM) and observe an improvement of the results against unsupervised and other semi-supervised clustering techniques.

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Deep Learning Architecture for Patient Data De-identification in Clinical Records
Shweta Yadav | Asif Ekbal | Sriparna Saha | Pushpak Bhattacharyya
Proceedings of the Clinical Natural Language Processing Workshop (ClinicalNLP)

Rapid growth in Electronic Medical Records (EMR) has emerged to an expansion of data in the clinical domain. The majority of the available health care information is sealed in the form of narrative documents which form the rich source of clinical information. Text mining of such clinical records has gained huge attention in various medical applications like treatment and decision making. However, medical records enclose patient Private Health Information (PHI) which can reveal the identities of the patients. In order to retain the privacy of patients, it is mandatory to remove all the PHI information prior to making it publicly available. The aim is to de-identify or encrypt the PHI from the patient medical records. In this paper, we propose an algorithm based on deep learning architecture to solve this problem. We perform de-identification of seven PHI terms from the clinical records. Experiments on benchmark datasets show that our proposed approach achieves encouraging performance, which is better than the baseline model developed with Conditional Random Field.

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IITP English-Hindi Machine Translation System at WAT 2016
Sukanta Sen | Debajyoty Banik | Asif Ekbal | Pushpak Bhattacharyya
Proceedings of the 3rd Workshop on Asian Translation (WAT2016)

In this paper we describe the system that we develop as part of our participation in WAT 2016. We develop a system based on hierarchical phrase-based SMT for English to Hindi language pair. We perform re-ordering and augment bilingual dictionary to improve the performance. As a baseline we use a phrase-based SMT model. The MT models are fine-tuned on the development set, and the best configurations are used to report the evaluation on the test set. Experiments show the BLEU of 13.71 on the benchmark test data. This is better compared to the official baseline BLEU score of 10.79.

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Can SMT and RBMT Improve each other’s Performance?- An Experiment with English-Hindi Translation
Debajyoty Banik | Sukanta Sen | Asif Ekbal | Pushpak Bhattacharyya
Proceedings of the 13th International Conference on Natural Language Processing

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Biomolecular Event Extraction using a Stacked Generalization based Classifier
Amit Majumder | Asif Ekbal | Sudip Kumar Naskar
Proceedings of the 13th International Conference on Natural Language Processing

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Improving Document Ranking using Query Expansion and Classification Techniques for Mixed Script Information Retrieval
Subham Kumar | Anwesh Sinha Ray | Sabyasachi Kamila | Asif Ekbal | Sriparna Saha | Pushpak Bhattacharyya
Proceedings of the 13th International Conference on Natural Language Processing

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A Recurrent Neural Network Architecture for De-identifying Clinical Records
Shweta | Ankit Kumar | Asif Ekbal | Sriparna Saha | Pushpak Bhattacharyya
Proceedings of the 13th International Conference on Natural Language Processing

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Opinion Mining in a Code-Mixed Environment: A Case Study with Government Portals
Deepak Gupta | Ankit Lamba | Asif Ekbal | Pushpak Bhattacharyya
Proceedings of the 13th International Conference on Natural Language Processing

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A Hybrid Deep Learning Architecture for Sentiment Analysis
Md Shad Akhtar | Ayush Kumar | Asif Ekbal | Pushpak Bhattacharyya
Proceedings of COLING 2016, the 26th International Conference on Computational Linguistics: Technical Papers

In this paper, we propose a novel hybrid deep learning archtecture which is highly efficient for sentiment analysis in resource-poor languages. We learn sentiment embedded vectors from the Convolutional Neural Network (CNN). These are augmented to a set of optimized features selected through a multi-objective optimization (MOO) framework. The sentiment augmented optimized vector obtained at the end is used for the training of SVM for sentiment classification. We evaluate our proposed approach for coarse-grained (i.e. sentence level) as well as fine-grained (i.e. aspect level) sentiment analysis on four Hindi datasets covering varying domains. In order to show that our proposed method is generic in nature we also evaluate it on two benchmark English datasets. Evaluation shows that the results of the proposed method are consistent across all the datasets and often outperforms the state-of-art systems. To the best of our knowledge, this is the very first attempt where such a deep learning model is used for less-resourced languages such as Hindi.

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Aspect based Sentiment Analysis in Hindi: Resource Creation and Evaluation
Md Shad Akhtar | Asif Ekbal | Pushpak Bhattacharyya
Proceedings of the Tenth International Conference on Language Resources and Evaluation (LREC'16)

Due to the phenomenal growth of online product reviews, sentiment analysis (SA) has gained huge attention, for example, by online service providers. A number of benchmark datasets for a wide range of domains have been made available for sentiment analysis, especially in resource-rich languages. In this paper we assess the challenges of SA in Hindi by providing a benchmark setup, where we create an annotated dataset of high quality, build machine learning models for sentiment analysis in order to show the effective usage of the dataset, and finally make the resource available to the community for further advancement of research. The dataset comprises of Hindi product reviews crawled from various online sources. Each sentence of the review is annotated with aspect term and its associated sentiment. As classification algorithms we use Conditional Random Filed (CRF) and Support Vector Machine (SVM) for aspect term extraction and sentiment analysis, respectively. Evaluation results show the average F-measure of 41.07% for aspect term extraction and accuracy of 54.05% for sentiment classification.

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Building Tempo-HindiWordNet: A resource for effective temporal information access in Hindi
Dipawesh Pawar | Mohammed Hasanuzzaman | Asif Ekbal
Proceedings of the Tenth International Conference on Language Resources and Evaluation (LREC'16)

In this paper, we put forward a strategy that supplements Hindi WordNet entries with information on the temporality of its word senses. Each synset of Hindi WordNet is automatically annotated to one of the five dimensions: past, present, future, neutral and atemporal. We use semi-supervised learning strategy to build temporal classifiers over the glosses of manually selected initial seed synsets. The classification process is iterated based on the repetitive confidence based expansion strategy of the initial seed list until cross-validation accuracy drops. The resource is unique in its nature as, to the best of our knowledge, still no such resource is available for Hindi.

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IIT-TUDA at SemEval-2016 Task 5: Beyond Sentiment Lexicon: Combining Domain Dependency and Distributional Semantics Features for Aspect Based Sentiment Analysis
Ayush Kumar | Sarah Kohail | Amit Kumar | Asif Ekbal | Chris Biemann
Proceedings of the 10th International Workshop on Semantic Evaluation (SemEval-2016)

2015

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IITP: Multiobjective Differential Evolution based Twitter Named Entity Recognition
Md Shad Akhtar | Utpal Kumar Sikdar | Asif Ekbal
Proceedings of the Workshop on Noisy User-generated Text

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IITP: Hybrid Approach for Text Normalization in Twitter
Md Shad Akhtar | Utpal Kumar Sikdar | Asif Ekbal
Proceedings of the Workshop on Noisy User-generated Text

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Simultaneous Feature Selection and Parameter Optimization Using Multi-objective Optimization for Sentiment Analysis
Mohammed Arif Khan | Asif Ekbal | Eneldo Loza Mencía
Proceedings of the 12th International Conference on Natural Language Processing

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IITPSemEval: Sentiment Discovery from 140 Characters
Ayush Kumar | Vamsi Krishna | Asif Ekbal
Proceedings of the 9th International Workshop on Semantic Evaluation (SemEval 2015)

2014

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Multiobjective Optimization and Unsupervised Lexical Acquisition for Named Entity Recognition and Classification
Govind | Asif Ekbal | Chris Biemann
Proceedings of the 11th International Conference on Natural Language Processing

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Determing Trustworthiness in E-Commerce Customer Reviews
Dhruv Gupta | Asif Ekbal
Proceedings of the 11th International Conference on Natural Language Processing

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IITP: A Supervised Approach for Disorder Mention Detection and Disambiguation
Utpal Kumar Sikdar | Asif Ekbal | Sriparna Saha
Proceedings of the 8th International Workshop on Semantic Evaluation (SemEval 2014)

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IITP: Supervised Machine Learning for Aspect based Sentiment Analysis
Deepak Kumar Gupta | Asif Ekbal
Proceedings of the 8th International Workshop on Semantic Evaluation (SemEval 2014)

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IITPatna: Supervised Approach for Sentiment Analysis in Twitter
Raja Selvarajan | Asif Ekbal
Proceedings of the 8th International Workshop on Semantic Evaluation (SemEval 2014)

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Indian Institute of Technology-Patna: Sentiment Analysis in Twitter
Vikram Singh | Arif Md. Khan | Asif Ekbal
Proceedings of the 8th International Workshop on Semantic Evaluation (SemEval 2014)

2013

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JU_CSE: A CRF Based Approach to Annotation of Temporal Expression, Event and Temporal Relations
Anup Kumar Kolya | Amitava Kundu | Rajdeep Gupta | Asif Ekbal | Sivaji Bandyopadhyay
Second Joint Conference on Lexical and Computational Semantics (*SEM), Volume 2: Proceedings of the Seventh International Workshop on Semantic Evaluation (SemEval 2013)

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Event and Event Actor Alignment in Phrase Based Statistical Machine Translation
Anup Kolya | Santanu Pal | Asif Ekbal | Sivaji Bandyopadhyay
Proceedings of the 11th Workshop on Asian Language Resources

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Adapting a State-of-the-art Anaphora Resolution System for Resource-poor Language
Utpal Sikdar | Asif Ekbal | Sriparna Saha | Olga Uryupina | Massimo Poesio
Proceedings of the Sixth International Joint Conference on Natural Language Processing

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Multi-Objective Optimization for Clustering of Medical Publications
Asif Ekbal | Sriparna Saha | Diego Mollá | K Ravikumar
Proceedings of the Australasian Language Technology Association Workshop 2013 (ALTA 2013)

2012

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Proceedings of the First International Workshop on Optimization Techniques for Human Language Technology
Pushpak Bhattacharyya | Asif Ekbal | Sriparna Saha | Mark Johnson | Diego Molla-Aliod | Mark Dras
Proceedings of the First International Workshop on Optimization Techniques for Human Language Technology

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Differential Evolution Based Feature Selection and Classifier Ensemble for Named Entity Recognition
Utpal Kumar Sikdar | Asif Ekbal | Sriparna Saha
Proceedings of COLING 2012

2011

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Single and multi-objective optimization for feature selection in anaphora resolution
Sriparna Saha | Asif Ekbal | Olga Uryupina | Massimo Poesio
Proceedings of 5th International Joint Conference on Natural Language Processing

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A Hybrid Approach for Event Extraction and Event Actor Identification
Anup Kumar Kolya | Asif Ekbal | Sivaji Bandyopadhyay
Proceedings of the International Conference Recent Advances in Natural Language Processing 2011

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Identifying Event-Sentiment Association using Lexical Equivalence and Co-reference Approaches
Anup Kolya | Dipankar Das | Asif Ekbal | Sivaji Bandyopadhyay
Proceedings of the ACL 2011 Workshop on Relational Models of Semantics

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Multi-metric optimization for coreference: The UniTN / IITP / Essex submission to the 2011 CONLL Shared Task
Olga Uryupina | Sriparna Saha | Asif Ekbal | Massimo Poesio
Proceedings of the Fifteenth Conference on Computational Natural Language Learning: Shared Task

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Proceedings of the Fifth International Workshop On Cross Lingual Information Access
Asif Ekbal | Deyi Xiong
Proceedings of the Fifth International Workshop On Cross Lingual Information Access

2010

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Maximum Entropy Classifier Ensembling using Genetic Algorithm for NER in Bengali
Asif Ekbal | Sriparna Saha
Proceedings of the Seventh International Conference on Language Resources and Evaluation (LREC'10)

In this paper, we propose classifier ensemble selection for Named Entity Recognition (NER) as a single objective optimization problem. Thereafter, we develop a method based on genetic algorithm (GA) to solve this problem. Our underlying assumption is that rather than searching for the best feature set for a particular classifier, ensembling of several classifiers which are trained using different feature representations could be a more fruitful approach. Maximum Entropy (ME) framework is used to generate a number of classifiers by considering the various combinations of the available features. In the proposed approach, classifiers are encoded in the chromosomes. A single measure of classification quality, namely F-measure is used as the objective function. Evaluation results on a resource constrained language like Bengali yield the recall, precision and F-measure values of 71.14%, 84.07% and 77.11%, respectively. Experiments also show that the classifier ensemble identified by the proposed GA based approach attains higher performance than all the individual classifiers and two different conventional baseline ensembles.

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Finding Appropriate Subset of Votes Per Classifier Using Multiobjective Optimization: Application to Named Entity Recognition
Asif Ekbal | Sriparna Saha | Md. Hasanuzzaman
Proceedings of the 24th Pacific Asia Conference on Language, Information and Computation

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Feature Subset Selection Using Genetic Algorithm for Named Entity Recognition
Md. Hasanuzzaman | Sriparna Saha | Asif Ekbal
Proceedings of the 24th Pacific Asia Conference on Language, Information and Computation

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A Supervised Machine Learning Approach for Event-Event Relation Identification
Anup Kumar Kolya | Asif Ekbal | Sivaji Bandyopadhyay
Proceedings of the 24th Pacific Asia Conference on Language, Information and Computation

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JU_CSE_TEMP: A First Step towards Evaluating Events, Time Expressions and Temporal Relations
Anup Kumar Kolya | Asif Ekbal | Sivaji Bandyopadhyay
Proceedings of the 5th International Workshop on Semantic Evaluation

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English to Indian Languages Machine Transliteration System at NEWS 2010
Amitava Das | Tanik Saikh | Tapabrata Mondal | Asif Ekbal | Sivaji Bandyopadhyay
Proceedings of the 2010 Named Entities Workshop

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Assessing the Challenge of Fine-Grained Named Entity Recognition and Classification
Asif Ekbal | Eva Sourjikova | Anette Frank | Simone Paolo Ponzetto
Proceedings of the 2010 Named Entities Workshop

2009

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Voted Approach for Part of Speech Tagging in Bengali
Asif Ekbal | Md. Hasanuzzaman | Sivaji Bandyopadhyay
Proceedings of the 23rd Pacific Asia Conference on Language, Information and Computation, Volume 1

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Named Entity Recognition for Manipuri Using Support Vector Machine
Thoudam Doren Singh | Kishorjit Nongmeikapam | Asif Ekbal | Sivaji Bandyopadhyay
Proceedings of the 23rd Pacific Asia Conference on Language, Information and Computation, Volume 2

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English to Hindi Machine Transliteration System at NEWS 2009
Amitava Das | Asif Ekbal | Tapabrata Mondal | Sivaji Bandyopadhyay
Proceedings of the 2009 Named Entities Workshop: Shared Task on Transliteration (NEWS 2009)

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Voted NER System using Appropriate Unlabeled Data
Asif Ekbal | Sivaji Bandyopadhyay
Proceedings of the 2009 Named Entities Workshop: Shared Task on Transliteration (NEWS 2009)

2008

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Multi-Engine Approach for Named Entity Recognition in Bengali
Asif Ekbal | Sivaji Bandyopadhyay
Proceedings of the 22nd Pacific Asia Conference on Language, Information and Computation

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Named Entity Recognition in Bengali: A Conditional Random Field Approach
Asif Ekbal | Rejwanul Haque | Sivaji Bandyopadhyay
Proceedings of the Third International Joint Conference on Natural Language Processing: Volume-II

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Language Independent Named Entity Recognition in Indian Languages
Asif Ekbal | Rejwanul Haque | Amitava Das | Venkateswarlu Poka | Sivaji Bandyopadhyay
Proceedings of the IJCNLP-08 Workshop on Named Entity Recognition for South and South East Asian Languages

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Bengali Named Entity Recognition Using Support Vector Machine
Asif Ekbal | Sivaji Bandyopadhyay
Proceedings of the IJCNLP-08 Workshop on Named Entity Recognition for South and South East Asian Languages

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Bengali, Hindi and Telugu to English Ad-hoc Bilingual Task
Sivaji Bandyopadhyay | Tapabrata Mondal | Sudip Kumar Naskar | Asif Ekbal | Rejwanul Haque | Srinivasa Rao Godavarthy
Proceedings of the 2nd workshop on Cross Lingual Information Access (CLIA) Addressing the Information Need of Multilingual Societies

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Development of Bengali Named Entity Tagged Corpus and its Use in NER Systems
Asif Ekbal | Sivaji Bandyopadhyay
Proceedings of the 6th Workshop on Asian Language Resources

2006

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A Modified Joint Source-Channel Model for Transliteration
Asif Ekbal | Sudip Kumar Naskar | Sivaji Bandyopadhyay
Proceedings of the COLING/ACL 2006 Main Conference Poster Sessions

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