We study the online facility location problem, where clients arrive sequentially in a random order and must be assigned to an open facility immediately and irrevocably upon arrival. At the initial stage, the set of facilities is fully known.

We present a 8-competitive online algorithm for the uniform facility cost case, providing the first competitive ratio result for this setting. Our algorithm reduces the competitive ratio by 75% compared to the previously known 33-competitive ratio for the nonuniform case. The analysis offers new theoretical insights into online algorithms for the nonuniform case and establishes a foundation for practical applications in decision-making contexts. (Joint work with Mengzhen Li, Runjie Miao, Chenchen Wu)

徐大川，北京工业大学数学系运筹学与控制论责任教授，数学/统计学博士生导师。研究兴趣包括：数学优化、机器学习与优化、博弈论等。北京运筹学会副理事长，APJOR、JORSC、运筹与管理等期刊编委。曾任中国运筹学会数学规划分会理事长，获中国运筹学会2022年度“最美科技工作者”。主持国家自然科学重点项目、国家重点研发计划“数学和应用研究”重点专项，与国内某著名公司合作完成通讯网络优化、深度学习中的优化算法课题2项，结题被评为优秀。出版学术专著2部，在Algorithmica、INFORMS Journal on Computing、Journal of Machine Learning Research、Mathematical Programming、Operations Research等发表学术论文100余篇。