26,836 research outputs found
Chiron: A Robust Recommendation System with Graph Regularizer
Recommendation systems have been widely used by commercial service providers
for giving suggestions to users. Collaborative filtering (CF) systems, one of
the most popular recommendation systems, utilize the history of behaviors of
the aggregate user-base to provide individual recommendations and are effective
when almost all users faithfully express their opinions. However, they are
vulnerable to malicious users biasing their inputs in order to change the
overall ratings of a specific group of items. CF systems largely fall into two
categories - neighborhood-based and (matrix) factorization-based - and the
presence of adversarial input can influence recommendations in both categories,
leading to instabilities in estimation and prediction. Although the robustness
of different collaborative filtering algorithms has been extensively studied,
designing an efficient system that is immune to manipulation remains a
significant challenge. In this work we propose a novel "hybrid" recommendation
system with an adaptive graph-based user/item similarity-regularization -
"Chiron". Chiron ties the performance benefits of dimensionality reduction
(through factorization) with the advantage of neighborhood clustering (through
regularization). We demonstrate, using extensive comparative experiments, that
Chiron is resistant to manipulation by large and lethal attacks
Stability of matrix factorization for collaborative filtering
We study the stability vis a vis adversarial noise of matrix factorization
algorithm for matrix completion. In particular, our results include: (I) we
bound the gap between the solution matrix of the factorization method and the
ground truth in terms of root mean square error; (II) we treat the matrix
factorization as a subspace fitting problem and analyze the difference between
the solution subspace and the ground truth; (III) we analyze the prediction
error of individual users based on the subspace stability. We apply these
results to the problem of collaborative filtering under manipulator attack,
which leads to useful insights and guidelines for collaborative filtering
system design.Comment: ICML201
Adversarial Training Towards Robust Multimedia Recommender System
With the prevalence of multimedia content on the Web, developing recommender
solutions that can effectively leverage the rich signal in multimedia data is
in urgent need. Owing to the success of deep neural networks in representation
learning, recent advance on multimedia recommendation has largely focused on
exploring deep learning methods to improve the recommendation accuracy. To
date, however, there has been little effort to investigate the robustness of
multimedia representation and its impact on the performance of multimedia
recommendation.
In this paper, we shed light on the robustness of multimedia recommender
system. Using the state-of-the-art recommendation framework and deep image
features, we demonstrate that the overall system is not robust, such that a
small (but purposeful) perturbation on the input image will severely decrease
the recommendation accuracy. This implies the possible weakness of multimedia
recommender system in predicting user preference, and more importantly, the
potential of improvement by enhancing its robustness. To this end, we propose a
novel solution named Adversarial Multimedia Recommendation (AMR), which can
lead to a more robust multimedia recommender model by using adversarial
learning. The idea is to train the model to defend an adversary, which adds
perturbations to the target image with the purpose of decreasing the model's
accuracy. We conduct experiments on two representative multimedia
recommendation tasks, namely, image recommendation and visually-aware product
recommendation. Extensive results verify the positive effect of adversarial
learning and demonstrate the effectiveness of our AMR method. Source codes are
available in https://github.com/duxy-me/AMR.Comment: TKD
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