diversity

Mean–variance portfolio optimization with shrinkage estimation for recommender systems

  • Yuichi Takano
    • Categories Integer Programming, Optimization in Data Science Tags , , , ,

    This paper is concerned with a mean-variance portfolio optimization model with cardinality constraint for generating high-quality lists of recommendations. It is usually difficult to accurately estimate the rating covariance matrix required for mean-variance portfolio optimization because of a shortage of observed user ratings. To improve the accuracy of covariance matrix estimation, we apply shrinkage estimation … Read more

    DiversiTree: A New Method to Efficiently Compute Diverse Sets of Near-Optimal Solutions to Mixed-Integer Optimization Problems

  • Izuwa Ahanor
  • Hugh R. Medal
  • Andrew C. Trapp
    • Categories Applications - Science and Engineering, Integer Programming, Other Topics Tags , , ,

    While most methods for solving mixed-integer optimization problems compute a single optimal solution, a diverse set of near-optimal solutions can often lead to improved outcomes. We present a new method for finding a set of diverse solutions by emphasizing diversity within the search for near-optimal solutions. Specifically, within a branch-and-bound framework, we investigated parameterized node … Read more

    Enriching Solutions to Combinatorial Problems via Solution Engineering

  • Petit Thierry
  • Andrew C. Trapp
    • Categories Combinatorial Optimization Tags , , , ,

    Existing approaches to identify multiple solutions to combinatorial problems in practice are at best limited in their ability to simultaneously incorporate both diversity among generated solutions, as well as problem-specific desires that are apriori unknown, or at least difficult to articulate, for the end-user. We propose a general framework that can generate a set of … Read more