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作者:Aravkin, Aleksandr; Friedlander, Michael P.; Herrmann, Felix J.; van Leeuwen, Tristan
作者单位:University of British Columbia; University of British Columbia
摘要:We consider a class of inverse problems in which the forward model is the solution operator to linear ODEs or PDEs. This class admits several dimensionality-reduction techniques based on data averaging or sampling, which are especially useful for large-scale problems. We survey these approaches and their connection to stochastic optimization. The data-averaging approach is only viable, however, for a least-squares misfit, which is sensitive to outliers in the data and artifacts unexplained by ...
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作者:Bandeira, A. S.; Scheinberg, K.; Vicente, L. N.
作者单位:Lehigh University; Princeton University; Universidade de Coimbra
摘要:Interpolation-based trust-region methods are an important class of algorithms for Derivative-Free Optimization which rely on locally approximating an objective function by quadratic polynomial interpolation models, frequently built from less points than there are basis components. Often, in practical applications, the contribution of the problem variables to the objective function is such that many pairwise correlations between variables are negligible, implying, in the smooth case, a sparse s...
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作者:Schuette, Christof; Winkelmann, Stefanie; Hartmann, Carsten
作者单位:Free University of Berlin
摘要:A numerical scheme for solving high-dimensional stochastic control problems on an infinite time horizon that appear relevant in the context of molecular dynamics is outlined. The scheme rests on the interpretation of the corresponding Hamilton-Jacobi-Bellman equation as a nonlinear eigenvalue problem that, using a logarithmic transformation, can be recast as a linear eigenvalue problem, for which the principal eigenvalue and its eigenfunction are sought. The latter can be computed efficiently ...
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作者:Misener, Ruth; Floudas, Christodoulos A.
作者单位:Princeton University
摘要:We propose a deterministic global optimization approach, whose novel contributions are rooted in the edge-concave and piecewise-linear underestimators, to address nonconvex mixed-integer quadratically-constrained quadratic programs (MIQCQP) to epsilon-global optimality. The facets of low-dimensional (n <= 3) edge-concave aggregations dominating the termwise relaxation of MIQCQP are introduced at every node of a branch-and-bound tree. Concave multivariable terms and sparsely distributed bilinea...
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作者:Byrd, Richard H.; Chin, Gillian M.; Nocedal, Jorge; Wu, Yuchen
作者单位:Northwestern University; University of Colorado System; University of Colorado Boulder; Alphabet Inc.; Google Incorporated
摘要:This paper presents a methodology for using varying sample sizes in batch-type optimization methods for large-scale machine learning problems. The first part of the paper deals with the delicate issue of dynamic sample selection in the evaluation of the function and gradient. We propose a criterion for increasing the sample size based on variance estimates obtained during the computation of a batch gradient. We establish an complexity bound on the total cost of a gradient method. The second pa...
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作者:Dorsch, D.; Guerra-Vazquez, F.; Guenzel, H.; Jongen, H. Th.; Rueckmann, J. -J.
作者单位:University of Birmingham; RWTH Aachen University; Universidad Americas Puebla (UDLAP)
摘要:We consider semi-infinite programming problems depending on a finite dimensional parameter . Provided that is a strongly stable stationary point of , there exists a locally unique and continuous stationary point mapping . This defines the local critical value function , where denotes the objective function of for a given parameter vector . We show that is the sum of a convex function and a smooth function. In particular, this excludes the appearance of negative kinks in the graph of .
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作者:Bansal, Nikhil
作者单位:Eindhoven University of Technology
摘要:Recently, there have been several new developments in discrepancy theory based on connections to semidefinite programming. This connection has been useful in several ways. It gives efficient polynomial time algorithms for several problems for which only non-constructive results were previously known. It also leads to several new structural results in discrepancy itself, such as tightness of the so-called determinant lower bound, improved bounds on the discrepancy of the union of set systems an...
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作者:Stein, Oliver; Steuermann, Paul
作者单位:Helmholtz Association; Karlsruhe Institute of Technology
摘要:A numerical solution method for semi-infinite optimization problems with arbitrary, not necessarily box-shaped, index sets is presented. Following the ideas of Floudas and Stein (SIAM J Optim 18:1187-1208, 2007), convex relaxations of the lower level problem are adaptively constructed and then reformulated as mathematical programs with complementarity constraints and solved. Although the index set is arbitrary, this approximation produces feasible iterates for the original problem. The convex ...
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作者:Chen, Xiaojun
作者单位:Hong Kong Polytechnic University
摘要:We consider a class of smoothing methods for minimization problems where the feasible set is convex but the objective function is not convex, not differentiable and perhaps not even locally Lipschitz at the solutions. Such optimization problems arise from wide applications including image restoration, signal reconstruction, variable selection, optimal control, stochastic equilibrium and spherical approximations. In this paper, we focus on smoothing methods for solving such optimization problem...
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作者:Curtis, Frank E.; Huber, Johannes; Schenk, Olaf; Waechter, Andreas
作者单位:Northwestern University; Lehigh University; University of Basel; Universita della Svizzera Italiana
摘要:This paper describes an implementation of an interior-point algorithm for large-scale nonlinear optimization. It is based on the algorithm proposed by Curtis et al. (SIAM J Sci Comput 32:3447-3475, 2010), a method that possesses global convergence guarantees to first-order stationary points with the novel feature that inexact search direction calculations are allowed in order to save computational expense. The implementation follows the proposed algorithm, but includes many practical enhanceme...