Applications – Science and Engineering

A Personalized Switched Systems Approach for the Optimal Control of Ventricular Assist Devices based on Atrioventricular Plane Displacement

  • Rüdiger C. Braun-Dullaeus
  • Sebastian Sager
  • Jeremi Kaj Mizerski
  • Thomas Rauwolf
  • Alexander Schmeisser
  • Clemens Zeile
    • Categories Biomedical Applications, Control Applications, Systems governed by Differential Equations Optimization Tags , , ,

    Objective: A promising treatment for congestive heart failure is the implementation of a left ventricular assist device (LVAD) that works as a mechanical pump. Modern LVADs work with adjustable constant rotor speed and provide therefore continuous blood flow; however, recently undertaken efforts try to mimic pulsatile blood flow by oscillating the pump speed. This work … Read more

    Consistent Second-Order Conic Integer Programming for Learning Bayesian Networks

  • Simge Küçükyavuz
  • Ali Shojaie
  • Hasan Manzour
  • Linchuan Wei
  • Hao-Hsiang Wu
    • Categories (Mixed) Integer Nonlinear Programming, Data-Mining, Network Optimization Tags , , , ,

    Bayesian Networks (BNs) represent conditional probability relations among a set of random variables (nodes) in the form of a directed acyclic graph (DAG), and have found diverse applications in knowledge discovery. We study the problem of learning the sparse DAG structure of a BN from continuous observational data. The central problem can be modeled as … Read more

    A decision theoretic approach for waveform design in joint radar communications applications

  • Daniel W. Bliss
  • Hans D Mittelmann
  • Alex R. Chiriyath
  • Shammy A. Doly
  • Shankarachary Ragi
    • Categories Applications - Science and Engineering

    In this paper, we develop a decision theoretic approach for radar waveform design to maximize the joint radar communications performance in spectral coexistence. Specifically, we develop an adaptive waveform design approach by posing the design problem as a partially observable Markov decision process (POMDP), which leads to a hard optimization problem. We extend an approximate … Read more

    Solving nonlinear systems of equations via spectral residual methods: stepsize selection and applications

  • Enrico Meli
  • Benedetta Morini
  • Margherita Porcelli
  • Cristina Sgattoni
    • Categories Mechanical Engineering, Nonlinear Systems and Least-Squares

    Spectral residual methods are derivative-free and low-cost per iteration procedures for solving nonlinear systems of equations. They are generally coupled with a nonmonotone linesearch strategy and compare well with Newton-based methods for large nonlinear systems and sequences of nonlinear systems. The residual vector is used as the search direction and choosing the steplength has a … Read more

    Reliable Frequency Regulation through Vehicle-to-Grid: Encoding Legislation with Robust Constraints

  • Dirk Lauinger
  • François Vuille
  • Daniel Kuhn
    • Categories Applications - OR and Management Sciences, Applications - Science and Engineering, Robust Optimization Tags , , , , ,

    Problem definition: Vehicle-to-grid increases the low utilization rate of privately owned electric vehicles by making their batteries available to electricity grids. We formulate a robust optimization problem that maximizes a vehicle owner’s expected profit from selling primary frequency regulation to the grid and guarantees that market commitments are met at all times for all frequency … Read more

    Solving Large-Scale Sparse PCA to Certifiable (Near) Optimality

  • Dimitris Bertsimas
  • Ryan Cory-Wright
  • Jean Pauphilet
    • Categories (Mixed) Integer Nonlinear Programming, Semi-definite Programming, Statistics Tags , , ,

    Sparse principal component analysis (PCA) is a popular dimensionality reduction technique for obtaining principal components which are linear combinations of a small subset of the original features. Existing approaches cannot supply certifiably optimal principal components with more than $p=100s$ of variables. By reformulating sparse PCA as a convex mixed-integer semidefinite optimization problem, we design a … Read more

    A tactical maintenance optimization model for multiple interconnected energy production systems

  • Silvia Anna Cordieri
  • Federico Malucelli
  • Ola Jabali
    • Categories (Mixed) Integer Linear Programming, Facility Planning and Design Tags , , , ,

    Multiple interconnected energy production systems are a common solution to satisfy the energy demand of industrial processes. Such energy demand is usually the combination of various energy types such as heat and electricity. This implies the installation of different technologies able to produce one or multiple energy types, to satisfy all energy needs. However, multiple … Read more

    Optimising the assignment of swabs and reagents for PCR testing during a viral epidemic

  • Alberto Santini
    • Categories Applications - OR and Management Sciences, Applications - Science and Engineering Tags , ,

    Early large-scale swab testing is a fundamental tool for health authorities to assess the prevalence of a virus and enact appropriate mitigation measures during an epidemic. The COVID-19 pandemic has shown that the availability of chemical reagents required to carry out the tests is often a bottleneck in increasing a country’s testing capacity. Further, demand … Read more

    Data Approximation by L1 Spline Fits with Free Knots

  • Ziteng Wang
  • Manfei Xie
    • Categories Applications - OR and Management Sciences, Applications - Science and Engineering, Nonlinear Optimization

    L1 spline fits are a class of spline models that have shown advantages in approximating irregular and multiscale data. This paper investigates the knot placement problem of L1 spline fits under two scenarios. If the number of knots is given, we propose an augmented Lagrangian method to solve the bilevel L1 spline fit problem and … Read more

    Enhancements to the DIDO© Optimal Control Toolbox

  • Isaac Ross
    • Categories Applications - Science and Engineering, Optimization Software and Modeling Systems, Optimization Software Design Principles Tags , , , ,

    In 2020, DIDO© turned 20! The software package emerged in 2001 as a basic, user-friendly MATLAB teaching tool to illustrate the various nuances of Pontryagin’s Principle but quickly rose to prominence in 2007 after NASA announced it had executed a globally optimal maneuver using DIDO. Since then, the toolbox has grown in applications well beyond … Read more