This paper studies the expressive power of artificial neural networks with rectified linear units. In order to study them as a model of real-valued computation, we introduce the concept of Max-Affine Arithmetic Progra...
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This paper studies the expressive power of artificial neural networks with rectified linear units. In order to study them as a model of real-valued computation, we introduce the concept of Max-Affine Arithmetic Programs and show equivalence between them and neural networks concerning natural complexity measures. We then use this result to show that two fundamental combinatorial optimization problems can be solved with polynomial-size neural networks. First, we show that for any undirected graph with n nodes, there is a neural network (with fixed weights and biases) of size O(n3)\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\mathcal {O}(n<^>3)$$\end{document} that takes the edge weights as input and computes the value of a minimum spanning tree of the graph. Second, we show that for any directed graph with n nodes and m arcs, there is a neural network of size O(m2n2)\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\mathcal {O}(m<^>2n<^>2)$$\end{document} that takes the arc capacities as input and computes a maximum flow. Our results imply that these two problems can be solved with stronglypolynomial time algorithms that solely use affine transformations and maxima computations, but no comparison-based branchings.
Inspired by the convex program of Eisenberg and Gale which captures Fisher markets with linear utilities, Jain and Vazirani [K. Jain and V. V. Vazirani, Games and Economic Behavior, 70 (2010), pp. 84-106] introduced t...
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Inspired by the convex program of Eisenberg and Gale which captures Fisher markets with linear utilities, Jain and Vazirani [K. Jain and V. V. Vazirani, Games and Economic Behavior, 70 (2010), pp. 84-106] introduced the class of Eisenberg-Gale (EG) markets. We study the structure of EG(2) markets, the class of EG markets with two agents. We prove that all markets in this class are rational, that is, they have rational equilibrium, and they admit stronglypolynomial time algorithms whenever the polytope containing the set of feasible utilities of the two agents can be described via a combinatorial linear program (LP). This helps positively resolve the status of two markets left as open problems by Jain and Vazirani: the capacity allocation market in a directed graph with two source-sink pairs and the network coding market in a directed network with two sources. Our algorithms for solving the corresponding nonlinear convex programs are fundamentally different from those obtained by Jain and Vazirani;whereas they use the primal-dual schema, our main tool is binary search powered by the strong LP-duality theorem.
A stronglypolynomial algorithm is given for the generalized flow maximization problem. It uses a new variant of the scaling technique called continuous scaling. The main measure of progress is that within a strongly ...
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A stronglypolynomial algorithm is given for the generalized flow maximization problem. It uses a new variant of the scaling technique called continuous scaling. The main measure of progress is that within a stronglypolynomial number of steps, an arc can be identified that must be tight in every dual optimal solution and thus can be contracted. As a consequence of the result, we also obtain a stronglypolynomial algorithm for the linear feasibility problem with at most two nonzero entries per column in the constraint matrix.
Huber et al. (SIAM J Comput 43: 1064-1084, 2014) introduced a concept of skew bisubmodularity, as a generalization of bisubmodularity, in their complexity dichotomy theorem for valued constraint satisfaction problems ...
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Huber et al. (SIAM J Comput 43: 1064-1084, 2014) introduced a concept of skew bisubmodularity, as a generalization of bisubmodularity, in their complexity dichotomy theorem for valued constraint satisfaction problems over the three-value domain, and Huber and Krokhin (SIAM J Discrete Math 28: 1828-1837, 2014) showed the oracle tractability of minimization of skew-bisubmodular functions. Fujishige et al. (Discrete Optim 12: 1-9, 2014) also showed a min-max theorem that characterizes the skew-bisubmodular function minimization, but devising a combinatorial polynomial algorithm for skew-bisubmodular function minimization was left open. In the present paper we give first combinatorial (weakly and strongly) polynomialalgorithms for skew-bisubmodular function minimization.
In this paper we show that the complexity of the simplex method for the linear fractional assignment problem (LFAP) is stronglypolynomial. Although LFAP can be solved in polynomial time using various algorithms such ...
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In this paper we show that the complexity of the simplex method for the linear fractional assignment problem (LFAP) is stronglypolynomial. Although LFAP can be solved in polynomial time using various algorithms such as Newton's method or binary search, no polynomial time bound for the simplex method for LFAP is known. (C) 2007 Elsevier B.V. All rights reserved.
In this paper we introduce a framework for the automatic generation of stronglypolynomial Fully polynomial Time Approximation Schemes (SFPTASes) for monotone dynamic programs. While some ad-hoc SFPTASes for specific ...
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In this paper we introduce a framework for the automatic generation of stronglypolynomial Fully polynomial Time Approximation Schemes (SFPTASes) for monotone dynamic programs. While some ad-hoc SFPTASes for specific problems are already known, this is the first framework yielding such SFPTASes. In addition, it is possible to use our algorithm to get efficient (non stronglypolynomial) FPTASes. Our results are derived by improving former (non stronglypolynomial) FPTASes which were designed via the method of K-approximation sets and functions. We demonstrate our SFPTAS framework on five application problems, namely, 0/1 Knapsack, counting 0/1 Knapsack, Counting s - t paths, Mobile agent routing and Counting n-tuples, for the last problem we get the fastest SFPTAS known to date. In addition, we use our algorithm to get the fastest (non stronglypolynomial) FPTASes for the following other three application problems: Stochastic ordered knapsack, Bi-criteria path problem with maximum survival probability and Minimizing the makespan of deteriorating jobs.
A well-studied nonlinear extension of the minimum-cost flow problem is to minimize the objective Sigma(ij is an element of Epsilon) C-ij (f(ij)) over feasible flows f, where on every arc ij of the network, C-ij is a c...
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A well-studied nonlinear extension of the minimum-cost flow problem is to minimize the objective Sigma(ij is an element of Epsilon) C-ij (f(ij)) over feasible flows f, where on every arc ij of the network, C-ij is a convex function. We give a stronglypolynomial algorithm for the case when all C-ij's are convex quadratic functions, settling an open problem raised, e.g., by Hochbaum [Math. Oper. Res., 19 (1994), pp. 390-409]. We also give strongly polynomial algorithms for computing market equilibria in Fisher markets with linear utilities and with spending constraint utilities that can be formulated in this framework (see Shmyrev [J. Appl. Ind. Math., 3 (2009), pp. 505-518], Birnbaum, Devanur, and Xiao [Proceedings of the 12th ACM Conference on Electronic Commerce, 2011, pp. 127-136]). For the latter class this resolves an open question raised by Vazirani [Math. Oper. Res., 35 (2010), pp. 458-478]. The running time is O(m(4) log m) for quadratic costs, O(n(4)+n(2)(m+n log n) log n) for Fisher's markets with linear utilities, and O(mn(3) + m(2)(m + n log n) logm) for spending constraint utilities. All these algorithms are presented in a common framework that addresses the general problem setting. Whereas it is impossible to give a stronglypolynomial algorithm for the general problem even in an approximate sense (see Hochbaum [Math. Oper. Res., 19 (1994), pp. 390-409]), we show that assuming the existence of certain black-box oracles, one can give an algorithm using a stronglypolynomial number of arithmetic operations and oracle calls only. The particular algorithms can be derived by implementing these oracles in the respective settings.
We present strongly polynomial algorithms to find rational and integer flow vectors that minimize a convex separable quadratic cost function on two-terminal series-parallel graphs.
We present strongly polynomial algorithms to find rational and integer flow vectors that minimize a convex separable quadratic cost function on two-terminal series-parallel graphs.
This paper studies the expressive power of artificial neural networks with rectified linear units. In order to study them as a model of real-valued computation, we introduce the concept of Max-Affine Arithmetic Progra...
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ISBN:
(数字)9783031327261
ISBN:
(纸本)9783031327254;9783031327261
This paper studies the expressive power of artificial neural networks with rectified linear units. In order to study them as a model of real-valued computation, we introduce the concept of Max-Affine Arithmetic Programs and show equivalence between them and neural networks concerning natural complexity measures. We then use this result to show that two fundamental combinatorial optimization problems can be solved with polynomial-size neural networks. First, we show that for any undirected graph with n nodes, there is a neural network (with fixed weights and biases) of size O( n(3)) that takes the edge weights as input and computes the value of a minimum spanning tree of the graph. Second, we show that for any directed graph with n nodes and m arcs, there is a neural network of size O(m(2)n(2)) that takes the arc capacities as input and computes a maximum flow. Our results imply that these two problems can be solved with stronglypolynomial time algorithms that solely uses affine transformations and maxima computations, but no comparison-based branchings.
A well-studied nonlinear extension of the minimum-cost flow problem is to minimize the objective E-ij is an element of E C-ij(f(ij)) over feasible flows f, where on every arc ij of the network, C-ij is a convex functi...
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ISBN:
(纸本)9781450312455
A well-studied nonlinear extension of the minimum-cost flow problem is to minimize the objective E-ij is an element of E C-ij(f(ij)) over feasible flows f, where on every arc ij of the network, C-ij is a convex function. We give a stronglypolynomial algorithm for finding an exact optimal solution for a broad class of such problems. The key characteristic of this class is that an optimal solution can be computed exactly provided its support. This includes separable convex quadratic objectives and also certain market equilibria problems: Fisher's market with linear and with spending constraint utilities. We thereby give the first strongly polynomial algorithms for separable quadratic minimum-cost flows and for Fisher's market with spending constraint utilities, settling open questions posed e.g. in [15] and in [35], respectively. The running time is O(m(4) log m) for quadratic costs, O(n(4)+n(2)(m+n log n) log n) for Fisher's markets with linear utilities and O(mn(3)+m(2)(m+ n log n) log m) for spending constraint utilities.
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