Tomas Lagos

Finding Groups with Maximum Betweenness Centrality via Integer Programming with Random Path Sampling

  • Tomas Lagos
  • Oleg A. Prokopyev
  • Alexander Veremyev
    • Categories Approximation Algorithms, Graphs and Matroids, Stochastic Approaches Tags , , , ,

    One popular approach to access the importance/influence of a group of nodes in a network is based on the notion of centrality. For a given group, its group betweenness centrality is computed, first, by evaluating a ratio of shortest paths between each node pair in a network that are “covered” by at least one node … Read more

    A Framework for Adaptive Open-pit Mining Planning under Geological Uncertainty

  • Margaret Armstrong
  • Tito Homem-de-Mello
  • Guido Lagos
  • Tomas Lagos
  • Denis Saure
    • Categories Dynamic Programming, Scheduling, Stochastic Programming Tags , , , ,

    Mine planning optimization aims at maximizing the profit obtained from extracting valuable ore. Beyond its theoretical complexity (the open-pit mining problem with capacity constraints reduces to a knapsack problem with precedence constraints, which is NP-hard), practical instances of the problem usually involve a large to very large number of decision variables, typically of the order … Read more