Improved Approximation Guarantees for Lower-Bounded Facility Location

13 years 5 months ago

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d Abstract) Sara Ahmadian∗ Chaitanya Swamy∗ We consider the lower-bounded facility location (LBFL) problem (also sometimes called load-balanced facility location), which is a generalization of uncapacitated facility location (UFL), where each open facility is required to serve a certain minimum amount of demand. More formally, an instance I of LBFL is speciﬁed by a set F of facilities with facility-opening costs {fi}, a set D of clients, and connection costs {cij} specifying the cost of assigning a client j to a facility i, where the cijs form a metric. A feasible solution speciﬁes a subset F of facilities to open, and assigns each client j to an open facility i(j) ∈ F so that each open facility serves at least M clients, where M is an input parameter. The cost of such a solution is i∈F fi + j ci(j)j, and the goal is to ﬁnd a feasible solution of minimum cost. The current best approximation ratio for LBFL is 448 [18]. We substantially advance the state-of-theart for LBFL...

Sara Ahmadian, Chaitanya Swamy

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