Supervised learning for image search result diversification

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2019

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Göynük, Burak

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Due to ambiguity of user queries and growing size of data living on the internet, methods for diversifying search results have gained more importance lately. While earlier works mostly focus on text search, a similar need also exists for image data, which grows rapidly as people produce and share image data via their smartphones and social media applications such as Instagram, Snapchat, and Facebook. Therefore, in this thesis, we focus on the result diversiﬁcation problem for image search. To this end, as our ﬁrst contribution, we adopt R-LTR, a supervised learning approach that has been proposed for textual data and modify it to allow tuning the weights of visual and textual features separately, as would be required for better diversiﬁcation. As a second contribution, we extend R-LTR by applying an alternative paradigm that takes into account an upperbound for the future diversity contribution that can be provided by the result being scored. We implement R-LTR and its variants using PyTorch’s neural network framework, which enables us to go beyond the original linear formulation. Finally, we create an ensemble of the most promising approaches for the image diversiﬁcation problem. Our experiments using a benchmark dataset with 153 queries and 45K images reveal that the adopted supervised algorithm, RLTR, signiﬁcantly outperforms various ad hoc diversiﬁcation approaches in terms of thesub-topicrecallmetric. Furthermore,certainvariantsofR-LTRproposedhereare superior to the original method and provide additional (relative) gains of up to 2.2%

Subject Keywords

Search engines., Keywords: information retrieval, search result diversification, image diversification, supervised learning, tensor.

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http://etd.lib.metu.edu.tr/upload/12624857/index.pdf
https://hdl.handle.net/11511/45127

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Graduate School of Natural and Applied Sciences, Thesis

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Citation Formats

B. Göynük, “Supervised learning for image search result diversification,” Thesis (M.S.) -- Graduate School of Natural and Applied Sciences. Computer Engineering., Middle East Technical University, 2019.