Applications – Science and Engineering

Three-dimensional quasi-static frictional contact by using second-order cone linear complementarity problem

  • Y. Kanno
  • J.A.C. Martins
  • A. Pinto da Costa
    • Categories Complementarity and Variational Inequalities, Mechanical Engineering, Second-Order Cone Programming

    A new formulation is presented for the three-dimensional incremental quasi-static problems with unilateral frictional contact. Under the assumptions of small rotations and small strains, a Second-Order Cone Linear omplementarity Problem (SOCLCP) is formulated, which consists of complementarity conditions defined by the bilinear functions and the second-order cone constraints. The equilibrium configurations are obtained by using … Read more

    Semidefinite descriptions of cones defining spectral mask constraints

  • Leonid Faybusovich
    • Categories Applications - Science and Engineering, Semi-definite Programming Tags , ,

    We discuss in detail an additive structure of cones of trigonometric polynomials nonnegative on the union of finite number of pairwise disjoint segments of the unit circle. We derive new descriptions of these cones in terms of semidefinite constraints. We explain the results of M. Krein and A. Nudelman providing a description of dual cones … Read more

    A randomized heuristic for scene recognition by graph matching

  • Isabelle Bloch
  • Celso C. Ribeiro
  • Maria Claudia Boeres
    • Categories Biomedical Applications, Graphs and Matroids, Meta Heuristics Tags , , , ,

    We propose a new strategy for solving the non-bijective graph matching problem in model-based pattern recognition. The search for the best correspondence between a model and an over-segmented image is formulated as a combinatorial optimization problem, defined by the relational attributed graphs representing the model and the image where recognition has to be performed, together … Read more

    Solving nonconvex SDP problems of structural optimization with stability control

  • Michal Kočvara
  • Michael Stingl
    • Categories Constrained Nonlinear Optimization, Mechanical Engineering, Semi-definite Programming Tags , , ,

    The goal of this paper is to formulate and solve structural optimization problems with constraints on the global stability of the structure. The stability constraint is based on the linear buckling phenomenon. We formulate the problem as a nonconvex semidefinite programming problem and introduce an algorithm based on the Augmented Lagrangian method combined with the … Read more

    On the modeling and control of delamination processes

  • Michal Kočvara
  • Jiri V. Outrata
    • Categories Constrained Nonlinear Optimization, Mechanical Engineering Tags , , ,

    This paper is motivated by problem of optimal shape design of laminated elastic bodies. We use a recently introduced model of delamination, based on minimization of potential energy which includes the free (Gibbs-type) energy and (pseudo)potential of dissipative forces, to introduce and analyze a special mathematical program with equilibrium constraints. The equilibrium is governed by … Read more

    Using Particle Swarm Optimization for Mixed Integer Non-linear Programming in Process Synthesis

  • Rongshan Bi
  • Xia Yang
    • Categories Applications - Science and Engineering Tags ,

    Process synthesis problems can be mathematically represented as mixed-integer nonlinear programming (MINLP) models, which are often irregular, large and non-convex and difficult to get the overall optimum by traditional method. In this paper, a new method named particle swarm optimization (PSO) is used to solve MINLP problems. By introduced penalty function and used sigmoid function, … Read more

    The dose-volume constraint satisfaction problem for inverse treatment planning with field segments

  • Yair Censor
  • James M. Galvin
  • Darek Michalski
  • Ying Xiao
    • Categories Biomedical Applications Tags , ,

    The prescribed goals of radiation treatment planning are often expressed in terms of dose-volume constraints. We present a novel formulation of a dose-volume constraint satisfaction search for the discretized radiation therapy model. This approach does not rely on any explicit cost function. The inverse treatment planning uses the aperture based approach with predefined, according to … Read more

    Linear-quadratic control problem with a linear term on semiinfinite interval:theory and applications

  • Leonid Faybusovich
  • Thanasak Mouktonglang
    • Categories Control Applications, Infinite Dimensional Optimization, Multi-Criteria Optimization Tags , ,

    We describe a complete solution of the linear-quaratic control problem with the linear term in the objective function on a semiinfinite interval. This problem has important applications to calculation of Nesterov-Todd and other primal-dual directions in infinite-dimensional setting. CitationTechnical report, University of Notre Dame, December, 2003ArticleDownload View PDF

    Transfer function restoration in 3D electron microscopy via iterative data refinement

  • J.M. Carazo
  • Yair Censor
  • C.O.S. Sorzano
  • Gabor T. Herman
  • R. Marabini
    • Categories Biomedical Applications Tags , ,

    Three-dimensional electron microscopy (3D-EM) is a powerful tool for visualizing complex biological systems. As any other imaging device, the electron microscope introduces a transfer function (called in this field the Contrast Transfer Function, CTF) into the image acquisition process that modulates the various frequencies of the signal. Thus, 3D reconstructions performed with these CTF-affected projections … Read more

    When LP is not a good idea – using structure in polyhedral optimization problems

  • Michael Osborne
    • Categories Convex Optimization, Linear Programming, Statistics Tags , , , , , , , , ,

    It has been known for almost 50 years that the discrete l_1 approximation problem can be solved effectively by linear programming. However, improved algorithms involve a step which can be interpreted as a line search, and which is not part of the standard LP solution procedures. l_1 provides the simplest example of a class of … Read more