Chenchen Wu

Primal-dual approximation algorithm for the two-level facility location problem via a dual quasi-greedy approach

The main contribution of this work is to propose a primal-dual combinatorial 3 ( 1 + e ) -approximation algorithm for the two-level facility location problem (2-LFLP) by exploring the approximation oracle concept. This result improves the previous primal-dual 6-approximation algorithm for the multilevel facility location problem, and also matches the previous primal-dual approximation ratio for the single-level facility location problem. One of the major merits of primal-dual type algorithms is their easy adaption to other variants of the facility location problems. As a demonstration, our primal-dual approximation algorithm can be easily adapted to several variants of the 2-LFLP, including models with stochastic scenario, dynamically arrived demands, and linear facility cost.

An improved semidefinite programming hierarchies rounding approximation algorithm for maximum graph bisection problems

We present a unified semidefinite programming hierarchies rounding approximation algorithm for a class of maximum graph bisection problems with improved approximation ratios. Under the above algorithmic framework, we show that the approximation ratios of Max-

Combinatorial approximation algorithms for the robust facility location problem with penalties

\frac{n}{2}

Approximation and Hardness Results for the Max k-Uncut Problem

n2-cut, Max-

A Complex Semidefinite Programming Rounding Approximation Algorithm for the Balanced Max-3-Uncut Problem

\frac{n}{2}

Local search algorithm for universal facility location problem with linear penalties

n2-dense-subgraph, and Max-