{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,21]],"date-time":"2026-04-21T17:07:18Z","timestamp":1776791238166,"version":"3.51.2"},"reference-count":44,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2022,6,2]],"date-time":"2022-06-02T00:00:00Z","timestamp":1654128000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100004281","name":"Norway Grants 2014\u20132021 operated by National Science Centre","doi-asserted-by":"publisher","award":["2020\/37\/K\/ST8\/02748"],"award-info":[{"award-number":["2020\/37\/K\/ST8\/02748"]}],"id":[{"id":"10.13039\/501100004281","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Unsupervised domain adaptation, which aims to alleviate the domain shift between source domain and target domain, has attracted extensive research interest; however, this is unlikely in practical application scenarios, which may be due to privacy issues and intellectual rights. In this paper, we discuss a more challenging and practical source-free unsupervised domain adaptation, which needs to adapt the source domain model to the target domain without the aid of source domain data. We propose label consistent contrastive learning (LCCL), an adaptive contrastive learning framework for source-free unsupervised domain adaptation, which encourages target domain samples to learn class-level discriminative features. Considering that the data in the source domain are unavailable, we introduce the memory bank to store the samples with the same pseudo label output and the samples obtained by clustering, and the trusted historical samples are involved in contrastive learning. In addition, we demonstrate that LCCL is a general framework that can be applied to unsupervised domain adaptation. Extensive experiments on digit recognition and image classification benchmark datasets demonstrate the effectiveness of the proposed method.<\/jats:p>","DOI":"10.3390\/s22114238","type":"journal-article","created":{"date-parts":[[2022,6,2]],"date-time":"2022-06-02T04:46:23Z","timestamp":1654145183000},"page":"4238","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":9,"title":["Adaptive Contrastive Learning with Label Consistency for Source Data Free Unsupervised Domain Adaptation"],"prefix":"10.3390","volume":"22","author":[{"given":"Xuejun","family":"Zhao","sequence":"first","affiliation":[{"name":"CRRC Academy Co., Ltd., Beijing 100070, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6014-3682","authenticated-orcid":false,"given":"Rafal","family":"Stanislawski","sequence":"additional","affiliation":[{"name":"Department of Electrical, Control and Computer Engineering, Opole University of Technology, 45-758 Opole, Poland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Paolo","family":"Gardoni","sequence":"additional","affiliation":[{"name":"Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, Champaign, IL 61820, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6436-1110","authenticated-orcid":false,"given":"Maciej","family":"Sulowicz","sequence":"additional","affiliation":[{"name":"Department of Electrical Engineering, Cracow University of Technology, 31-155 Cracow, Poland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0546-7083","authenticated-orcid":false,"given":"Adam","family":"Glowacz","sequence":"additional","affiliation":[{"name":"Department of Electrical Engineering, Cracow University of Technology, 31-155 Cracow, Poland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2967-1719","authenticated-orcid":false,"given":"Grzegorz","family":"Krolczyk","sequence":"additional","affiliation":[{"name":"Faculty of Mechanical Engineering, Opole University of Technology, 45-758 Opole, Poland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7265-0008","authenticated-orcid":false,"given":"Zhixiong","family":"Li","sequence":"additional","affiliation":[{"name":"Faculty of Mechanical Engineering, Opole University of Technology, 45-758 Opole, Poland"},{"name":"Yonsei Frontier Lab, Yonsei University, Seoul 03722, Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2022,6,2]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"He, K., Zhang, X., Ren, S., and Sun, J. 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