Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: FedCL: Federated Contrastive Learning for Privacy-Preserving
  Recommendation   Contrastive learning is widely used for recommendation model learning, where
selecting representative and informative negative samples is critical. Existing
methods usually focus on centralized data, where abundant and high-quality
negative samples are easy to obtain. However, centralized user data storage and
exploitation may lead to privacy risks and concerns, while decentralized user
data on a single client can be too sparse and biased for accurate contrastive
learning. In this paper, we propose a federated contrastive learning method
named FedCL for privacy-preserving recommendation, which can exploit
high-quality negative samples for effective model training with privacy well
protected. We first infer user embeddings from local user data through the
local model on each client, and then perturb them with local differential
privacy (LDP) before sending them to a central server for hard negative
sampling. Since individual user embedding contains heavy noise due to LDP, we
propose to cluster user embeddings on the server to mitigate the influence of
noise, and the cluster centroids are used to retrieve hard negative samples
from the item pool. These hard negative samples are delivered to user clients
and mixed with the observed negative samples from local data as well as
in-batch negatives constructed from positive samples for federated model
training. Extensive experiments on four benchmark datasets show FedCL can
empower various recommendation methods in a privacy-preserving way.

31
The categories of this paper are: ao-sci
36
The categories of this paper are: cmp-lg
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The categories of this paper are: econ
23
The categories of this paper are: solv-int
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The categories of this paper are: math
0
The categories of this paper are: hep-ph
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The categories of this paper are: chao-dyn
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The categories of this paper are: math-ph
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The categories of this paper are: eess
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The categories of this paper are: mtrl-th
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The categories of this paper are: chem-ph
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The categories of this paper are: hep-ex
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The categories of this paper are: atom-ph
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The categories of this paper are: patt-sol
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The categories of this paper are: comp-gas
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The categories of this paper are: plasm-ph