收录:
摘要:
In this paper, we consider the tau-relaxed soft capacitated facility location problem (tau-relaxed SCFLP), which extends several well-known facility location problems like the squared metric soft capacitated facility location problem (SMSCFLP), soft capacitated facility location problem (SCFLP), squared metric facility location problem and uncapacitated facility location problem. In the tau-relaxed SCFLP, we are given a facility set F, a client set and a parameter tau >= 1. Every facility i is an element of F has a capacity u(i) and an opening cost f(i), and can be opened multiple times. If facility i is opened l times, this facility can be connected by at most lu(i) clients and incurs an opening cost of l f(i). Every facility-client pair has a connection cost. Under the assumption that the connection costs are non-negative, symmetric and satisfy the tau-relaxed triangle inequality, we wish to open some facilities (once or multiple times) and connect every client to an opened facility without violating the capacity constraint so as to minimize the total opening costs as well as connection costs. As our main contribution, we propose a primal-dual based (3 tau + 1)-approximation algorithm for the tau-relaxed SCFLP. Furthermore, our algorithm not only extends the applicability of the primal-dual technique but also improves the previous approximation guarantee for the SMSCFLP from 11.18 + epsilon to 10.
关键词:
通讯作者信息: