Convex Optimization

Equivalence and Strong Equivalence between Sparsest and Least l1-Norm Nonnegative Solutions of Linear Systems and Their Application

  • Yun-Bin Zhao
    • Categories Convex Optimization, Global Optimization, Linear Programming Tags , , , ,

    Many practical problems can be formulated as $\ell_0$-minimization problems with nonnegativity constraints, which seek the sparsest nonnegative solutions to underdetermined linear systems. Recent study indicates that $\ell_1$-minimization is efficient for solving some classes of $\ell_0$-minimization problems. From a mathematical point of view, however, the understanding of the relationship between $\ell_0$- and $\ell_1$-minimization remains incomplete. In … Read more

    Active Set Methods with Reoptimization for Convex Quadratic Integer Programming

  • Christoph Buchheim
  • Long Trieu
    • Categories (Mixed) Integer Nonlinear Programming, Convex Optimization, Quadratic Programming Tags , ,

    We present a fast branch-and-bound algorithm for solving convex quadratic integer programs with few linear constraints. In each node, we solve the dual problem of the continuous relaxation using an infeasible active set method proposed by Kunisch and Rendl to get a lower bound; this active set algorithm is well suited for reoptimization. Our algorithm … Read more

    On the Convergence of Alternating Minimization for Convex Programming with Applications to Iteratively Reweighted Least Squares and Decomposition Schemes

  • Amir Beck
    • Categories Convex Optimization

    This paper is concerned with the alternating minimization (AM) for solving convex minimization problems where the decision variables vector is split into two blocks. The objective function is a sum of a differentiable convex function and a separable (possible) nonsmooth extended real-valued convex function, and consequently constraints can be incorporated. We analyze the convergence rate … Read more

    On the Proximal Jacobian Decomposition of ALM for Multiple-block Separable Convex Minimization Problems and its Relationship to ADMM

  • Bingsheng He
  • Xiao-Ming Yuan
  • Hong-Kun Xu
    • Categories Convex Optimization Tags , , , , , ,

    The augmented Lagrangian method (ALM) is a benchmark for solving convex minimization problems with linear constraints. When the objective function of the model under consideration is representable as the sum of some functions without coupled variables, a Jacobian or Gauss-Seidel decomposition is often implemented to decompose the ALM subproblems so that the functions’ properties could … Read more

    Practical Inexact Proximal Quasi-Newton Method with Global Complexity Analysis

  • Katya Scheinberg
  • Xiaocheng Tang
    • Categories Convex Optimization, Nonsmooth Optimization Tags , , ,

    Recently several methods were proposed for sparse optimization which make careful use of second-order information [11, 30, 17, 3] to improve local convergence rates. These methods construct a composite quadratic approximation using Hessian information, optimize this approximation using a first-order method, such as coordinate descent and employ a line search to ensure sufficient descent. Here … Read more

    An inexact proximal path-following algorithm for constrained convex minimization

  • Volkan Cevher
  • Quoc Tran-Dinh
  • Anastasios Kyrillidis
    • Categories Convex and Nonsmooth Optimization, Convex Optimization, Linear, Cone and Semidefinite Programming Tags , , , ,

    Many scientific and engineering applications feature large-scale non-smooth convex minimization problems over convex sets. In this paper, we address an important instance of this broad class where we assume that the non-smooth objective is equipped with a tractable proximity operator and that the convex constraints afford a self-concordant barrier. We provide a new joint treatment … Read more

    A First-Order Algorithm for the A-Optimal Experimental Design Problem: A Mathematical Programming Approach

  • Selin Damla Ahipasaoglu
    • Categories Convex Optimization, Semi-definite Programming, Statistics Tags , ,

    We develop and analyse a first-order algorithm for the A-optimal experimental design problem. The problem is first presented as a special case of a parametric family of optimal design problems for which duality results and optimality conditions are given. Then, two first-order (Frank-Wolfe type) algorithms are presented, accompanied by a detailed time-complexity analysis of the … Read more

    Accelerating block-decomposition first-order methods for solving composite saddle-point and two-player Nash equilibrium problems

  • Yunlong He
  • Renato D.C. Monteiro
    • Categories Convex Optimization, Generalized Convexity/Monoticity, Nonsmooth Optimization Tags , , , , , ,

    This article considers the two-player composite Nash equilibrium (CNE) problem with a separable non-smooth part, which is known to include the composite saddle-point (CSP) problem as a special case. Due to its two-block structure, this problem can be solved by any algorithm belonging to the block-decomposition hybrid proximal-extragradient (BD-HPE) framework. The framework consists of a … Read more

    On the Convergence of Decentralized Gradient Descent

  • Qing Ling
  • Wotao Yin
  • Kun Yuan
    • Categories Convex Optimization Tags ,

    Consider the consensus problem of minimizing $f(x)=\sum_{i=1}^n f_i(x)$ where each $f_i$ is only known to one individual agent $i$ out of a connected network of $n$ agents. All the agents shall collaboratively solve this problem and obtain the solution subject to data exchanges restricted to between neighboring agents. Such algorithms avoid the need of a … Read more

    Iteration-Complexity of a Generalized Forward Backward Splitting Algorithm

  • Jalal Fadili
  • Jingwei Liang
  • Gabriel Peyré
    • Categories Convex Optimization Tags , , ,

    In this paper, we analyze the iteration-complexity of a generalized forward-backward (GFB) splitting algorithm, recently proposed in~\cite{gfb2011}, for minimizing the large class of composite objectives $f + \sum_{i=1}^n h_i$ on a Hilbert space, where $f$ has a Lipschitz-continuous gradient and the $h_i$’s are simple (i.e. whose proximity operator is easily computable ). We derive iteration-complexity … Read more