收录:
摘要:
In this paper, we consider the lower-bounded k-median problem (LB k-median) that extends the classical k-median problem. In the LB k-median, a set of facilities, a set of clients and an integer k are given. Every facility has its own lower bound on the minimum number of clients that must be connected to the facility if it is opened. Every facility-client pair has its connection cost. We want to open at most k facilities and connect every client to some opened facility, such that the total connection cost is minimized. As our main contribution, we study the LB k-median and present our main bi-criteria approximation algorithm, which, for any given constant, outputs a solution that satisfies the lower bound constraints by a factor of and has an approximation ratio of, where is the state-of-art approximation ratio for the k-facility location problem (k-FL). Then, by extending the main algorithm to several general versions of the LB k-median, we show the versatility of our algorithm for the LB k-median. Last, through providing relationships between the constant and the approximation ratios, we demonstrate the performances of all the algorithms for the LB k-median and its generalizations. © 2020, Springer Nature Switzerland AG.
关键词:
通讯作者信息:
电子邮件地址: