Applications – Science and Engineering

Developments in mathematical algorithms and computational tools for proton CT and particle therapy treatment planning

  • Yair Censor
  • Keith E. Schubert
  • Reinhard W. Schulte
    • Categories Basic Sciences Applications, Biomedical Applications, Constrained Nonlinear Optimization Tags , , , , , , , ,

    We summarize recent results and ongoing activities in mathematical algorithms and computer science methods related to proton computed tomography (pCT) and intensitymodulated particle therapy (IMPT) treatment planning. Proton therapy necessitates a high level of delivery accuracy to exploit the selective targeting imparted by the Bragg peak. For this purpose, pCT utilizes the proton beam itself … Read more

    Designing reliable future energy systems by iteratively including extreme periods in time-series aggregation

  • Adam R. Brandt
  • Lucas Elias Kuepper
  • Holger Teichgraeber
    • Categories Energy, Facility Planning and Design

    Generation Capacity Expansion Planning (GCEP) requires high temporal resolution to account for the volatility of renewable energy supply. Because the GCEP optimization problem is often computationally intractable, time-series input data are often aggregated to representative periods using clustering. However, clustering removes extreme events, which are important to achieve reliable system designs. We present a method … Read more

    Solving a Class of Cut-Generating Linear Programs via Machine Learning

  • Danial Davarnia
  • Atefeh Rajabalizadeh
    • Categories Branch and Cut Algorithms, Data-Mining, Linear Programming Tags , , , ,

    Cut-generating linear programs (CGLPs) play a key role as a separation oracle to produce valid inequalities for the feasible region of mixed-integer programs. When incorporated inside branch-and-bound, the cutting planes obtained from CGLPs help to tighten relaxations and improve dual bounds. However, running the CGLPs at the nodes of the branch-and-bound tree is computationally cumbersome … Read more

    Interpretable Policies and the Price of Interpretability in Hypertension Treatment Planning

  • Gian-Gabriel Garcia
  • Wesley Marrero
  • Lauren Steimle
  • Jeremy Sussman
    • Categories Applications - OR and Management Sciences, Applications - Science and Engineering, Dynamic Programming Tags , , , , ,

    Problem definition: Effective hypertension management is critical to reducing consequences of atherosclerotic cardiovascular disease, a leading cause of death in the United States. Clinical guidelines for hypertension can be enhanced using decision-analytic approaches, capable of capturing many complexities in treatment planning. However, model-generated recommendations may be uninterpretable/unintuitive, limiting their acceptability in practice. We address this … Read more

    Decision Intelligence for Nationwide Ventilator Allocation

  • Jiajun Xu
  • Suvrajeet Sen
    • Categories Applications - OR and Management Sciences, Basic Sciences Applications, Optimization of Simulated Systems Tags , , , ,

    Many states in the U.S. have faced shortages of medical resources because of the surge in the number of patients suffering from COVID-19. As many projections indicate, the situation will be far worse in coming months. The upcoming challenge is not only due to the exponential growth in cases but also because of inherent uncertainty … Read more

    Locating Platforms and Scheduling a Fleet of Drones for Emergency Delivery of Perishable Items

  • Alessandro Agnetis
  • Monica Gentili
  • Zabih Ghelichi
  • Pitu Mirchandani
    • Categories Applications - OR and Management Sciences, Applications - Science and Engineering, Integer Programming Tags , ,

    Motivated by issues dealing with delivery of emergency medical products during humanitarian disasters, this paper addresses the general problem of delivering perishable items to remote demands accessible only by helicopters or drones. Each drone operates out of platforms that may be moved when not in use and each drone has a limited delivery range to … Read more

    Full-low evaluation methods for derivative-free optimization

  • Albert S. Berahas
  • Luis Nunes Vicente
  • Oumaima Sohab
    • Categories Applications - Science and Engineering, Convex and Nonsmooth Optimization, Nonlinear Optimization Tags , , ,

    We propose a new class of rigorous methods for derivative-free optimization with the aim of delivering efficient and robust numerical performance for functions of all types, from smooth to non-smooth, and under different noise regimes. To this end, we have developed Full-Low Evaluation methods, organized around two main types of iterations. The first iteration type … Read more

    Robust Integration of Electric Vehicles Charging Load in Smart Grid’s Capacity Expansion Planning

  • Sajad Aliakbari-Sani
  • Olivier Bahn
  • Erick Delage
  • Rinel Foguen Tchuendom
    • Categories Energy, Game Theory, Robust Optimization Tags , , ,

    Battery charging of electric vehicles (EVs) needs to be properly coordinated by electricity producers to maintain network reliability. In this paper, we propose a robust approach to model the interaction between a large fleet of EV users and utilities in a long-term generation expansion planning problem. In doing so, we employ a robust multi-period adjustable … Read more

    Designing an optimal sequence of non-pharmaceutical interventions for controlling COVID-19

  • Laurent Alfandari
  • Debajyoti Biswas
    • Categories Biomedical Applications

    The COVID-19 pandemic has had an unprecedented impact on global health and the economy since its inception in December, 2019 in Wuhan, China. Non-pharmaceutical interventions (NPI) like lockdowns and curfews have been deployed by affected countries for controlling the spread of infections. In this paper, we develop a Mixed Integer Non-Linear Programming (MINLP) epidemic model … Read more

    What is the optimal cutoff surface for ore bodies with more than one mineral?

  • Lewis Ntaimo
  • Bernardo K. Pagnoncelli
  • A. Piazza
    • Categories Applications - OR and Management Sciences, Control Applications, Dynamic Programming

    In mine planning problems, cutoff grade optimization defines a threshold at every time period such that material above this value is processed, and the rest is considered waste. In orebodies with multiple minerals, which occur in practice, the natural extension is to consider a cutoff surface. We show that in two dimensions the optimal solution … Read more