{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,15]],"date-time":"2026-01-15T00:38:12Z","timestamp":1768437492319,"version":"3.49.0"},"publisher-location":"California","reference-count":0,"publisher":"International Joint Conferences on Artificial Intelligence Organization","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2019,8]]},"abstract":"<jats:p>Classic multi-armed bandit algorithms are inefficient for a large number of arms. On the other hand, contextual bandit algorithms are more efficient, but they suffer from a large regret due to the bias of reward estimation with finite dimensional features. Although recent studies proposed semi-parametric bandits to overcome these defects, they assume arms' features are constant over time. However, this assumption rarely holds in practice, since real-world problems often involve underlying processes that are dynamically evolving over time especially for the special promotions like Singles' Day sales. In this paper, we formulate a novel Semi-Parametric Contextual Bandit Problem to relax this assumption. For this problem, a novel Two-Steps Upper-Confidence Bound framework, called Semi-Parametric UCB (SPUCB), is presented. It can be flexibly applied to linear parametric function problem with a satisfied gap-free bound on the n-step regret. Moreover, to make our method more practical in online system, an optimization is proposed for dealing with high dimensional features of a linear function. Extensive experiments on synthetic data as well as a real dataset from one of the largest e-commercial platforms demonstrate the superior performance of our algorithm.<\/jats:p>","DOI":"10.24963\/ijcai.2019\/450","type":"proceedings-article","created":{"date-parts":[[2019,7,28]],"date-time":"2019-07-28T03:46:05Z","timestamp":1564285565000},"page":"3246-3252","source":"Crossref","is-referenced-by-count":4,"title":["A Practical Semi-Parametric Contextual Bandit"],"prefix":"10.24963","author":[{"given":"Yi","family":"Peng","sequence":"first","affiliation":[{"name":"Alibaba Group, Hang Zhou, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Miao","family":"Xie","sequence":"additional","affiliation":[{"name":"Alibaba Group, Hang Zhou, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jiahao","family":"Liu","sequence":"additional","affiliation":[{"name":"Alibaba Group, Hang Zhou, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Xuying","family":"Meng","sequence":"additional","affiliation":[{"name":"Institute of Computing Technology, Chinese Academy of Sciences"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Nan","family":"Li","sequence":"additional","affiliation":[{"name":"Alibaba Group, Hang Zhou, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Cheng","family":"Yang","sequence":"additional","affiliation":[{"name":"Alibaba Group, Hang Zhou, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Tao","family":"Yao","sequence":"additional","affiliation":[{"name":"Alibaba Group, Hang Zhou, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Rong","family":"Jin","sequence":"additional","affiliation":[{"name":"Alibaba Group, Hang Zhou, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"10584","event":{"name":"Twenty-Eighth International Joint Conference on Artificial Intelligence {IJCAI-19}","theme":"Artificial Intelligence","location":"Macao, China","acronym":"IJCAI-2019","number":"28","sponsor":["International Joint Conferences on Artificial Intelligence Organization (IJCAI)"],"start":{"date-parts":[[2019,8,10]]},"end":{"date-parts":[[2019,8,16]]}},"container-title":["Proceedings of the Twenty-Eighth International Joint Conference on Artificial Intelligence"],"original-title":[],"deposited":{"date-parts":[[2019,7,28]],"date-time":"2019-07-28T03:49:23Z","timestamp":1564285763000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.ijcai.org\/proceedings\/2019\/450"}},"subtitle":[],"proceedings-subject":"Artificial Intelligence Research Articles","short-title":[],"issued":{"date-parts":[[2019,8]]},"references-count":0,"URL":"https:\/\/doi.org\/10.24963\/ijcai.2019\/450","relation":{},"subject":[],"published":{"date-parts":[[2019,8]]}}}