Nisansa de Silva


2021

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Semantic Oppositeness Assisted Deep Contextual Modeling for Automatic Rumor Detection in Social Networks
Nisansa de Silva | Dejing Dou
Proceedings of the 16th Conference of the European Chapter of the Association for Computational Linguistics: Main Volume

Social networks face a major challenge in the form of rumors and fake news, due to their intrinsic nature of connecting users to millions of others, and of giving any individual the power to post anything. Given the rapid, widespread dissemination of information in social networks, manually detecting suspicious news is sub-optimal. Thus, research on automatic rumor detection has become a necessity. Previous works in the domain have utilized the reply relations between posts, as well as the semantic similarity between the main post and its context, consisting of replies, in order to obtain state-of-the-art performance. In this work, we demonstrate that semantic oppositeness can improve the performance on the task of rumor detection. We show that semantic oppositeness captures elements of discord, which are not properly covered by previous efforts, which only utilize semantic similarity or reply structure. We show, with extensive experiments on recent data sets for this problem, that our proposed model achieves state-of-the-art performance. Further, we show that our model is more resistant to the variances in performance introduced by randomness.

2020

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Exploiting Node Content for Multiview Graph Convolutional Network and Adversarial Regularization
Qiuhao Lu | Nisansa de Silva | Dejing Dou | Thien Huu Nguyen | Prithviraj Sen | Berthold Reinwald | Yunyao Li
Proceedings of the 28th International Conference on Computational Linguistics

Network representation learning (NRL) is crucial in the area of graph learning. Recently, graph autoencoders and its variants have gained much attention and popularity among various types of node embedding approaches. Most existing graph autoencoder-based methods aim to minimize the reconstruction errors of the input network while not explicitly considering the semantic relatedness between nodes. In this paper, we propose a novel network embedding method which models the consistency across different views of networks. More specifically, we create a second view from the input network which captures the relation between nodes based on node content and enforce the latent representations from the two views to be consistent by incorporating a multiview adversarial regularization module. The experimental studies on benchmark datasets prove the effectiveness of this method, and demonstrate that our method compares favorably with the state-of-the-art algorithms on challenging tasks such as link prediction and node clustering. We also evaluate our method on a real-world application, i.e., 30-day unplanned ICU readmission prediction, and achieve promising results compared with several baseline methods.

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Effective Approach to Develop a Sentiment Annotator For Legal Domain in a Low Resource Setting
Gathika Ratnayaka | Nisansa de Silva | Amal Shehan Perera | Ramesh Pathirana
Proceedings of the 34th Pacific Asia Conference on Language, Information and Computation

2018

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Fast Approach to Build an Automatic Sentiment Annotator for Legal Domain using Transfer Learning
Viraj Salaka | Menuka Warushavithana | Nisansa de Silva | Amal Shehan Perera | Gathika Ratnayaka | Thejan Rupasinghe
Proceedings of the 9th Workshop on Computational Approaches to Subjectivity, Sentiment and Social Media Analysis

This study proposes a novel way of identifying the sentiment of the phrases used in the legal domain. The added complexity of the language used in law, and the inability of the existing systems to accurately predict the sentiments of words in law are the main motivations behind this study. This is a transfer learning approach which can be used for other domain adaptation tasks as well. The proposed methodology achieves an improvement of over 6% compared to the source model’s accuracy in the legal domain.

2014

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Building a WordNet for Sinhala
Indeewari Wijesiri | Malaka Gallage | Buddhika Gunathilaka | Madhuranga Lakjeewa | Daya Wimalasuriya | Gihan Dias | Rohini Paranavithana | Nisansa de Silva
Proceedings of the Seventh Global Wordnet Conference