Ioannis Tsochantaridis

Ioannis Tsochantaridis

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    Preview abstract We propose a lightweight real-time sign language detection model, as we identify the need for such a case in videoconferencing. We extract optical flow features based on human pose estimation and, using a linear classifier, show these features are meaningful with an accuracy of 80%, evaluated on the DGS Corpus. Using a recurrent model directly on the input, we see improvements of up to 91% accuracy, while still working under 4ms. We describe a demo application to sign language detection in the browser in order to demonstrate its usage possibility in videoconferencing applications. View details
    Statistical Machine Translation for Query Expansion in Answer Retrieval
    Stefan Riezler
    Alexander Vasserman
    Vibhu Mittal
    Yi Liu
    Proceedings of the 45th Annual Meeting of the Association for Computational Linguistics (ACL'07), Prague, Czech Republic(2007)
    Preview abstract This paper presents a novel approach to query expansion in answer retrieval that uses Statistical Machine Translation (SMT) techniques to bridge the lexical gap between questions and answers. SMT-based query expansion is performed on the one hand by using a SMT-based full-sentence paraphraser to introduce synonyms in the context the full query, and on the other hand by training an SMT model on question-answer pairs and expanding queries by answer terms taken from translations of full queries. We compare these global, context-aware query expansion techniques with a baseline tfidf model and local query expansion on a database of 10 million question-answer pairs extracted from FAQ pages. Experimental results show a significant improvement of SMT-based query expansion over both baselines. View details