16,101 research outputs found
Adversarial Sampling and Training for Semi-Supervised Information Retrieval
Ad-hoc retrieval models with implicit feedback often have problems, e.g., the
imbalanced classes in the data set. Too few clicked documents may hurt
generalization ability of the models, whereas too many non-clicked documents
may harm effectiveness of the models and efficiency of training. In addition,
recent neural network-based models are vulnerable to adversarial examples due
to the linear nature in them. To solve the problems at the same time, we
propose an adversarial sampling and training framework to learn ad-hoc
retrieval models with implicit feedback. Our key idea is (i) to augment clicked
examples by adversarial training for better generalization and (ii) to obtain
very informational non-clicked examples by adversarial sampling and training.
Experiments are performed on benchmark data sets for common ad-hoc retrieval
tasks such as Web search, item recommendation, and question answering.
Experimental results indicate that the proposed approaches significantly
outperform strong baselines especially for high-ranked documents, and they
outperform IRGAN in NDCG@5 using only 5% of labeled data for the Web search
task.Comment: Published in WWW 201
Unsupervised Visual and Textual Information Fusion in Multimedia Retrieval - A Graph-based Point of View
Multimedia collections are more than ever growing in size and diversity.
Effective multimedia retrieval systems are thus critical to access these
datasets from the end-user perspective and in a scalable way. We are interested
in repositories of image/text multimedia objects and we study multimodal
information fusion techniques in the context of content based multimedia
information retrieval. We focus on graph based methods which have proven to
provide state-of-the-art performances. We particularly examine two of such
methods : cross-media similarities and random walk based scores. From a
theoretical viewpoint, we propose a unifying graph based framework which
encompasses the two aforementioned approaches. Our proposal allows us to
highlight the core features one should consider when using a graph based
technique for the combination of visual and textual information. We compare
cross-media and random walk based results using three different real-world
datasets. From a practical standpoint, our extended empirical analysis allow us
to provide insights and guidelines about the use of graph based methods for
multimodal information fusion in content based multimedia information
retrieval.Comment: An extended version of the paper: Visual and Textual Information
Fusion in Multimedia Retrieval using Semantic Filtering and Graph based
Methods, by J. Ah-Pine, G. Csurka and S. Clinchant, submitted to ACM
Transactions on Information System
A semi-supervised learning algorithm for relevance feedback and collaborative image retrieval
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)The interaction of users with search services has been recognized as an important mechanism for expressing and handling user information needs. One traditional approach for supporting such interactive search relies on exploiting relevance feedbacks (RF) in the searching process. For large-scale multimedia collections, however, the user efforts required in RF search sessions is considerable. In this paper, we address this issue by proposing a novel semi-supervised approach for implementing RF-based search services. In our approach, supervised learning is performed taking advantage of relevance labels provided by users. Later, an unsupervised learning step is performed with the objective of extracting useful information from the intrinsic dataset structure. Furthermore, our hybrid learning approach considers feedbacks of different users, in collaborative image retrieval (CIR) scenarios. In these scenarios, the relationships among the feedbacks provided by different users are exploited, further reducing the collective efforts. Conducted experiments involving shape, color, and texture datasets demonstrate the effectiveness of the proposed approach. Similar results are also observed in experiments considering multimodal image retrieval tasks.The interaction of users with search services has been recognized as an important mechanism for expressing and handling user information needs. One traditional approach for supporting such interactive search relies on exploiting relevance feedbacks (RF) i2015FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIORFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FAPESP [2013/08645-0, 2013/50169-1]CNPq [306580/2012-8, 484254/2012-0]2013/08645-0; 2013/50169-1306580/2012-8;484254/2012-0SEM INFORMAÇÃ
Exploring EEG for Object Detection and Retrieval
This paper explores the potential for using Brain Computer Interfaces (BCI)
as a relevance feedback mechanism in content-based image retrieval. We
investigate if it is possible to capture useful EEG signals to detect if
relevant objects are present in a dataset of realistic and complex images. We
perform several experiments using a rapid serial visual presentation (RSVP) of
images at different rates (5Hz and 10Hz) on 8 users with different degrees of
familiarization with BCI and the dataset. We then use the feedback from the BCI
and mouse-based interfaces to retrieve localized objects in a subset of TRECVid
images. We show that it is indeed possible to detect such objects in complex
images and, also, that users with previous knowledge on the dataset or
experience with the RSVP outperform others. When the users have limited time to
annotate the images (100 seconds in our experiments) both interfaces are
comparable in performance. Comparing our best users in a retrieval task, we
found that EEG-based relevance feedback outperforms mouse-based feedback. The
realistic and complex image dataset differentiates our work from previous
studies on EEG for image retrieval.Comment: This preprint is the full version of a short paper accepted in the
ACM International Conference on Multimedia Retrieval (ICMR) 2015 (Shanghai,
China
IRGAN: A Minimax Game for Unifying Generative and Discriminative Information Retrieval Models
This paper provides a unified account of two schools of thinking in
information retrieval modelling: the generative retrieval focusing on
predicting relevant documents given a query, and the discriminative retrieval
focusing on predicting relevancy given a query-document pair. We propose a game
theoretical minimax game to iteratively optimise both models. On one hand, the
discriminative model, aiming to mine signals from labelled and unlabelled data,
provides guidance to train the generative model towards fitting the underlying
relevance distribution over documents given the query. On the other hand, the
generative model, acting as an attacker to the current discriminative model,
generates difficult examples for the discriminative model in an adversarial way
by minimising its discrimination objective. With the competition between these
two models, we show that the unified framework takes advantage of both schools
of thinking: (i) the generative model learns to fit the relevance distribution
over documents via the signals from the discriminative model, and (ii) the
discriminative model is able to exploit the unlabelled data selected by the
generative model to achieve a better estimation for document ranking. Our
experimental results have demonstrated significant performance gains as much as
23.96% on Precision@5 and 15.50% on MAP over strong baselines in a variety of
applications including web search, item recommendation, and question answering.Comment: 12 pages; appendix adde
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