Registered Data

[CT064]

[02632] Bidimensional Empirical Mode Decomposition (BEMD) for Texture Analysis

  • Session Date & Time : 2C (Aug.22, 13:20-15:00)
  • Type : Contributed Talk
  • Abstract : Surface texture is evaluated on solid surfaces by BEMD decomposition in order to obtain different spatial scale components associated to surface functional performance. At each point, a neighboring window scheme is introduced to extract local extrema and obtain the spatial spectrum. An adaptive algorithm is applied to automatically select the optimal window and plot the local extreme and the subsequent local mean envelope surfaces. Successive BEMD components are obtained from high to low scales.
  • Classification : 47N70, 41-04, 74E25, 40-08, 70K75
  • Author(s) :
    • Rosa Piotrkowski (ITECA (UNSAM-CONICET), ECyT, Universidad Nacional de San Martín, Buenos Aires, Argentina)
    • Marcela Morvidone (ITECA (UNSAM-CONICET), ECyT, Universidad Nacional de San Martín, Buenos Aires, Argentina)
    • Diana Rubio (ITECA (UNSAM-CONICET), ECyT, Universidad Nacional de San Martín, Buenos Aires, Argentina)

[00997] A Normal Map-Based Perspective on Second Order Theory for Composite Problems: Second Order Conditions, Metric Regularity, and Nonsingularity

  • Session Date & Time : 2C (Aug.22, 13:20-15:00)
  • Type : Contributed Talk
  • Abstract : Strong metric subregularity and strong metric regularity of the natural residual and the normal map are of particular importance in the convergence analysis of first-order and second-order algorithms for composite-type optimization problems. In this talk, we characterize the strong metric subregularity of the natural residual and the normal map for a general class of nonsmooth nonconvex composite functions and establish the equivalence between these conditions, the strong metric subregularity of the subdifferential, and the quadratic growth condition. Furthermore, if the nonsmooth part of the objective function has a strictly decomposable structure, then strong metric regularity of the subdifferential is shown to be equivalent to strong metric regularity of natural residual and the normal map and to a counterpart of the so-called strong second-order sufficient conditions. Finally, we provide a link of these conditions to nonsingularity of the generalized Jacobians of the normal map and natural residual.
  • Classification : 47Nxx, 47Nxx, 47Nxx, 47Nxx, 47Nxx, Variational Analysis
  • Author(s) :
    • Wenqing Ouyang (The Chinese University of HongKong(Shenzhen))
    • Andre Manfred Milzarek (The Chinese University of Hong Kong, Shenzhen)

[01247] Gradient-push algorithm for distributed optimization with event-triggered communications

  • Session Date & Time : 2C (Aug.22, 13:20-15:00)
  • Type : Contributed Talk
  • Abstract : Decentralized optimization problems consist of multiple agents connected by a network. The agents have each local cost function, and the goal is to minimize the sum of the functions cooperatively. In this work, we propose a gradient-push algorithm involving event-triggered communication on a directed network. The convergence of the algorithm is established under suitable decays and summability conditions on a stepsize and triggering threshold.
  • Classification : 47Nxx, 65Kxx, Decentralized Optimization
  • Author(s) :
    • jimyeong kim (Sungkyunkwan University)
    • Woocheol Choi (Sungkyunkwan Univeristiy)

[00648] Bounds for effective conductivity of multimaterial composites

  • Session Date & Time : 2C (Aug.22, 13:20-15:00)
  • Type : Contributed Talk
  • Abstract : The paper discusses the exact bounds for the effective properties of multimaterial composites. We refine Hashin-Shtrikman bounds in the region where the last ones are loose. We show that fields in optimal structures vary in restricted domains, modify the Translation method, and obtain new exact bounds and optimal structures. Different volume fractions of components correspond to topologically different types of optimal structures.
  • Classification : 49K20
  • Author(s) :
    • Andrej Cherkaev (University of Utah)

[01946] Optimal Control of Stationary Doubly Diffusive Flows on Lipschitz Domains

  • Session Date & Time : 2C (Aug.22, 13:20-15:00)
  • Type : Contributed Talk
  • Abstract : Doubly diffusive flows involve coupled incompressible flow and double diffusion transport, which models physical problems like bacteria bioconvection, exothermic flows in oceanography and more. We study a distributed optimal control problem governed by doubly diffusive flows under minimal regularity on 2D and 3D bounded Lipschitz domains and establish its well-posedness. First and second-order optimality conditions are derived. Furthermore, a discretization of the control problem based on $H(\mbox{div})$-conforming discontinuous Galerkin finite elements for the state and adjoint variables and piecewise constant finite elements for the control variable is discussed. Optimal apriori error estimates are proven in suitable norms. Numerical experiments are performed using a semi-smooth Newton strategy verifying the theoretical findings.
  • Classification : 49K20, 65N30, 76S05, 76R50, 49K27
  • Author(s) :
    • Jai Tushar (Indian Institute of Technology Roorkee)
    • Arbaz Khan (IIT Roorkee)
    • Manil T. Mohan ( IIT Roorkee)