报告题目：Optimal Cyclic (r, δ) Locally Repairable Codes with Unbounded Length

报告人:符方伟教授（南开大学陈身省数学研究所）

报告时间：2021年3月6日15:00—18:00

报告地点：数理楼一楼小报告厅 145

报告摘要：Locally repairable codes (LRCs) are introduced with the aim of reducing the cost of repairing a failed node. An locally repairable code with locality r (r-LRC for short) is a linear code such that every code symbol can be recovered by accessing at most r other code symbols. An r-LRC is called optimal if it achieves the Singleton-type bound. The (r, δ) locally repairable codes ((r, δ)-LRCs for short) are introduced for tolerating multiple failed nodes. An r-LRC can be viewed as an (r, 2)-LRC. An (r, δ)-LRC is called optimal if it achieves the Singleton-type bound. Luo et al. presented a construction of q-ary optimal r-LRCs of minimum distances 3 and 4 with unbounded lengths (i.e., lengths of these codes are independent of q) via cyclic codes. In this talk, inspired by their work, we construct several classes of optimal cyclic (r, δ)-LRCs with unbounded lengths and minimum distances between δ+1 and 2δ, which generalize their results for the δ=2 case. Finally, we propose some further research problems.

报告人简介：

符方伟，分别于1984年、1987年和1990年获得南开大学理学（数学）学士、硕士和博士学位。1987年7月至今在南开大学数学科学学院工作。现为南开大学陈省身数学研究所教授和博士生导师、中国电子学会信息论分会副主任委员、中国密码学会理事、中国密码学会密码数学理论专业委员会副主任委员、学术期刊《密码学报》和《电子与信息学报》的编委。入选2000年度教育部跨世纪优秀人才培养计划。2000年获国务院政府特殊津贴。主要从事编码理论及其应用、密码学及其应用、信息论及其应用的研究工作，在国际和国内重要学术期刊上发表论文200余篇。作为负责人承担了国家自然科学基金和教育部的多项科研项目，作为课题负责人承担了科技部973项目和国家重点研发计划项目。