Evidence of Exponential Speed-Up in the Solution of Hard Optimization Problems

Optimization problems pervade essentially every scientific discipline and industry. A common form requires identifying a solution satisfying the maximum number among a set of many conflicting constraints. Often, these problems are particularly difficult to solve, requiring resources that grow expone...

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Main Authors: Fabio L. Traversa, Pietro Cicotti, Forrest Sheldon, Massimiliano Di Ventra
Format: Article
Language:English
Published: Wiley 2018-01-01
Series:Complexity
Online Access:http://dx.doi.org/10.1155/2018/7982851
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author Fabio L. Traversa
Pietro Cicotti
Forrest Sheldon
Massimiliano Di Ventra
author_facet Fabio L. Traversa
Pietro Cicotti
Forrest Sheldon
Massimiliano Di Ventra
author_sort Fabio L. Traversa
collection DOAJ
description Optimization problems pervade essentially every scientific discipline and industry. A common form requires identifying a solution satisfying the maximum number among a set of many conflicting constraints. Often, these problems are particularly difficult to solve, requiring resources that grow exponentially with the size of the problem. Over the past decades, research has focused on developing heuristic approaches that attempt to find an approximation to the solution. However, despite numerous research efforts, in many cases even approximations to the optimal solution are hard to find, as the computational time for further refining a candidate solution also grows exponentially with input size. In this paper, we show a noncombinatorial approach to hard optimization problems that achieves an exponential speed-up and finds better approximations than the current state of the art. First, we map the optimization problem into a Boolean circuit made of specially designed, self-organizing logic gates, which can be built with (nonquantum) electronic elements with memory. The equilibrium points of the circuit represent the approximation to the problem at hand. Then, we solve its associated nonlinear ordinary differential equations numerically, towards the equilibrium points. We demonstrate this exponential gain by comparing a sequential MATLAB implementation of our solver with the winners of the 2016 Max-SAT competition on a variety of hard optimization instances. We show empirical evidence that our solver scales linearly with the size of the problem, both in time and memory, and argue that this property derives from the collective behavior of the simulated physical circuit. Our approach can be applied to other types of optimization problems, and the results presented here have far-reaching consequences in many fields.
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spelling doaj-art-7066cf9345f14227b6881417b42925502025-02-03T05:53:47ZengWileyComplexity1076-27871099-05262018-01-01201810.1155/2018/79828517982851Evidence of Exponential Speed-Up in the Solution of Hard Optimization ProblemsFabio L. Traversa0Pietro Cicotti1Forrest Sheldon2Massimiliano Di Ventra3MemComputing Inc., San Diego, CA 92130, USASan Diego Supercomputer Center, La Jolla, CA 92093, USADepartment of Physics, University of California, La Jolla, San Diego, CA 92093, USADepartment of Physics, University of California, La Jolla, San Diego, CA 92093, USAOptimization problems pervade essentially every scientific discipline and industry. A common form requires identifying a solution satisfying the maximum number among a set of many conflicting constraints. Often, these problems are particularly difficult to solve, requiring resources that grow exponentially with the size of the problem. Over the past decades, research has focused on developing heuristic approaches that attempt to find an approximation to the solution. However, despite numerous research efforts, in many cases even approximations to the optimal solution are hard to find, as the computational time for further refining a candidate solution also grows exponentially with input size. In this paper, we show a noncombinatorial approach to hard optimization problems that achieves an exponential speed-up and finds better approximations than the current state of the art. First, we map the optimization problem into a Boolean circuit made of specially designed, self-organizing logic gates, which can be built with (nonquantum) electronic elements with memory. The equilibrium points of the circuit represent the approximation to the problem at hand. Then, we solve its associated nonlinear ordinary differential equations numerically, towards the equilibrium points. We demonstrate this exponential gain by comparing a sequential MATLAB implementation of our solver with the winners of the 2016 Max-SAT competition on a variety of hard optimization instances. We show empirical evidence that our solver scales linearly with the size of the problem, both in time and memory, and argue that this property derives from the collective behavior of the simulated physical circuit. Our approach can be applied to other types of optimization problems, and the results presented here have far-reaching consequences in many fields.http://dx.doi.org/10.1155/2018/7982851
spellingShingle Fabio L. Traversa
Pietro Cicotti
Forrest Sheldon
Massimiliano Di Ventra
Evidence of Exponential Speed-Up in the Solution of Hard Optimization Problems
Complexity
title Evidence of Exponential Speed-Up in the Solution of Hard Optimization Problems
title_full Evidence of Exponential Speed-Up in the Solution of Hard Optimization Problems
title_fullStr Evidence of Exponential Speed-Up in the Solution of Hard Optimization Problems
title_full_unstemmed Evidence of Exponential Speed-Up in the Solution of Hard Optimization Problems
title_short Evidence of Exponential Speed-Up in the Solution of Hard Optimization Problems
title_sort evidence of exponential speed up in the solution of hard optimization problems
url http://dx.doi.org/10.1155/2018/7982851
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