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作者:Khademnia, Erfan; Davarnia, Danial
作者单位:Iowa State University
摘要:It is well-known that the McCormick relaxation for the bilinear constraint z = xy gives the convex hull over the box domains for x and y . In network applications where the domain of bilinear variables is described by a network polytope, the McCormick relaxation, also referred to as linearization, fails to provide the convex hull and often leads to poor dual bounds. We study the convex hull of the set containing bilinear constraints z i , j = xiyj i y j where xi i represents the arc -flow vari...
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作者:Cohen, Eyal; Teboulle, Marc
作者单位:Tel Aviv University
摘要:There is growing interest in nonconvex minimax problems that is driven by an abundance of applications. Our focus is on nonsmooth, nonconvex-strongly concave minimax, thus departing from the more common weakly convex and smooth models assumed in the recent literature. We present proximal gradient schemes with either parallel or alternating steps. We show that both methods can be analyzed through a single scheme within a unified analysis that relies on expanding a general convergence mechanism ...
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作者:Giannakopoulos, Yiannis; Melissourgos, Themistoklis; Grosz, Alexander
作者单位:University of Glasgow; Technical University of Munich; University of Essex
摘要:We propose a unifying framework for smoothed analysis of combinatorial local optimization problems and show how a variety of problems within the complexity class PLS (Polynomial Local Search) can be cast within this model. This abstraction enables identifying key structural properties, and corresponding parameters, that determine the smoothed running time of local search dynamics. Our black-box tool provides concrete bounds on the expected maximum number of steps needed until local search reac...
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作者:Jiao, Liguo; Lee, Jae Hyoung; Pham, Tien-Son
作者单位:Northeast Normal University - China; Pukyong National University; Dalat University
摘要:We are interested in optimality conditions for semialgebraic vector optimization problems with a situation in which generalized (weakly) nondominated points do exist but are not attained as image points of (weakly) efficient solutions. To this end, cones associated with unbounded semialgebraic sets at infinity are introduced and studied. Then, optimality conditions at infinity in terms of the Newton polyhedra of the objective mappings and of the cones associated with the constraint sets at inf...
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作者:Ma, Jianhao; Fattahi, Salar
作者单位:University of Michigan System; University of Michigan
摘要:We explore the local landscape of low-rank matrix recovery, focusing on reconstructing a d1 x d2 matrix X* with rank r from m linear measurements, some potentially noisy. When the noise is distributed according to an outlier model, minimizing a nonsmooth & ell;1-loss with a simple subgradient method can often perfectly recover the ground truth matrix X*. Given this, a natural question is what optimization property (if any) enables such learning behavior. The most plausible answer is that the g...
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作者:Faenza, Yuri; He, Chengyue; Sethuraman, Jay
作者单位:Columbia University
摘要:Scarf's algorithm gives a pivoting procedure to find a special vertex-a dominating vertex-in a down-monotone polytope. This paper studies the behavior of Scarf's algorithm when employed to find stable matchings in bipartite graphs. First, it proves that Scarf's algorithm can be implemented to run in polynomial time, showing the first positive result on its runtime in significant settings. Second, it shows an infinite family of instances where, no matter the pivoting rule and runtime, Scarf's a...
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作者:Schlotter, Ildiko; Biro, Peter; Fleinera, Tamas
作者单位:HUN-REN; HUN-REN Centre for Economic & Regional Studies; Budapest University of Technology & Economics; Corvinus University Budapest
摘要:We study housing markets as introduced by Shapley and Scarf. We investigate the computational complexity of various questions regarding the situation of an agent a in a housing market H: we show that it is NP-hard to find an allocation in the core of H in which (i) a receives a certain house, (ii) a does not receive a certain house, or (iii) a receives a house other than a's own. We prove that the core of housing markets respects improvement in the following sense: given an allocation in the c...
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作者:Lykouris, Thodoris; Simchowitz, Max; Slivkins, Aleksandrs; Sun, Wen
作者单位:Massachusetts Institute of Technology (MIT); Massachusetts Institute of Technology (MIT); Cornell University
摘要:We initiate the study of episodic reinforcement learning (RL) under adversarial corruptions in both the rewards and the transition probabilities of the underlying system, extending recent results for the special case of multiarmed bandits. We provide a framework that modifies the aggressive exploration enjoyed by existing reinforcement learning approaches based on optimism in the face of uncertainty by complementing them with principles from action elimination. Importantly, our framework circu...
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作者:Lindstrom, Scott B.; Lourenco, Bruno F.; Pong, Ting Kei
作者单位:Curtin University; Research Organization of Information & Systems (ROIS); Institute of Statistical Mathematics (ISM) - Japan; Hong Kong Polytechnic University
摘要:We prove tight Holderian lderian error bounds for all p -cones. Surprisingly, the exponents differ in several ways from those that have been previously conjectured. Moreover, they illuminate p -cones as a curious example of a class of objects that possess properties in three dimensions that they do not in four or more. Using our error bounds, we analyse least squares problems with p -norm regularization, where our results enable us to compute the corresponding Kurdyka-& Lstrok;ojasiewicz expon...
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作者:Goldsztajn, Diego; Borst, Sem C.; van Leeuwaarden, Johan S. H.
作者单位:Eindhoven University of Technology; Inria; Tilburg University
摘要:Consider a system of identical server pools where tasks with exponentially distributed service times arrive as a time-inhomogeneous Poisson process. An admission threshold is used in an inner control loop to assign incoming tasks to server pools, while in an outer control loop, a learning scheme adjusts this threshold over time to keep it aligned with the unknown offered load of the system. In a many-server regime, we prove that the learning scheme reaches an equilibrium along intervals of tim...