Grey Median Problem and Vertex Optimality

GPU-based parallel vertex substitution algorithm for the p-median problem

We introduce a GPU-based parallel Vertex Substitution (pVS) algorithm for the p-median problem using the CUDA architecture by NVIDIA. pVS is developed based on the best profit search algorithm, an implementation of Vertex Substitution (VS), that is shown to produce reliable solutions for p-median problems. In our approach, each candidate solution in the entire search space is allocated to a sep...

The robust vertex centdian location problem with interval vertex weights on general graphs

In this paper, the robust vertex centdian  location  problem with uncertain vertex weights on general graphs is studied. The used criterion to solve the problem is the min-max  regret criterion. This problem  is  investigated  with objective function contains $lambda$  and  a polynomial time algorithm for the problem is presented. It is shown that the vertex centdian problem on general graphs i...

The Reversal Median Problem

The Online Median Problem

We introduce a natural variant of the (metric uncapacitated) k-median problem that we call the online median problem. Whereas the k-median problem involves optimizing the simultaneous placement of k facilities, the online median problem imposes the following additional constraints: the facilities are placed one at a time; a facility cannot be moved once it is placed, and the total number of fac...

The p-Median Problem

The p-median problem is central to much of discrete location modeling and theory. While the p-median problem is NP-hard on a general graph, it can be solved in polynomial time on a tree. A linear time algorithm for the 1-median problem on a tree is described. We also present a classical formulation of the problem. Basic construction and improvement algorithms are outlined. Results from the lite...