Hamidreza Validi

A Note on “A linear-size zero-one programming model for the minimum spanning tree problem in planar graphs”

  • Austin Buchanan
  • Hamidreza Validi
    • Categories Combinatorial Optimization, Integer Programming

    In the paper “A linear-size zero-one programming model for the minimum spanning tree problem in planar graphs” (Networks 39(1):53–60, 2002), Williams introduced an extended formulation for the spanning tree polytope of a planar graph. This formulation is remarkably small (using only $O(n)$ variables and constraints) and remarkably strong (defining an integral polytope). In this note, … Read more

    The optimal design of low-latency virtual backbones

  • Austin Buchanan
  • Hamidreza Validi
    • Categories Branch and Cut Algorithms, Integer Programming, Network Optimization

    Two nodes of a wireless network may not be able to communicate with each other directly perhaps due to obstacles or insufficient signal strength. This necessitates the use of intermediate nodes to relay information. Often, one designates a (preferably small) subset of them to relay these messages (i.e., to serve as a virtual backbone for … Read more