We study the computationalcomplexity of computing optimal solutions (the solutions themselves, not just their cost) for NP optimization problems where the costs of feasible solutions are bounded above by a polynomial...
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We study the computationalcomplexity of computing optimal solutions (the solutions themselves, not just their cost) for NP optimization problems where the costs of feasible solutions are bounded above by a polynomial in the length of their instances (we simply denote by NPOP such an NP optimization problem). It is of particular interest to find a computational structure (or equivalently, a complexity class) which. captures that complexity, if we consider the problems of computing optimal solutions for NPOP’s as a class of functions giving those optimal solutions. In this paper, we will observe that the class of functions computable in polynomial-time with one free evaluation of unbounded parallel queries to NP oracle sets, captures that complexity. We first show that for any NPOP Π, there exists a polynomial-time bounded randomized algorithm which, given an instance of Π, uses one free evaluation of parallel queries to an NP oracle set and outputs some optimal solution of the instance with very high probability. We then show that for several natural NPOP’s, any function giving those optimal solutions is at least as computationally hard as all functions in . To show the hardness results, we introduce a property of NPOP’s, called paddability , and we show a general result that if Π is a paddable NPOP and its associated decision problem is NP-hard, then all functions in are computable in polynomial-time with one free evaluation of an arbitrary function giving optimal solutions for instances of Π. The hardness results are applications of this general result. Among the NPOP’s, we include MAXIMUM CLIQUE, MINIMUM COLORING, LONGEST PATH, LONGEST CYCLE, 0–1 TRAVELING SALESPERSON, and 0–1 INTEGER PROGRAMMING.
In the framework of membrane computing, several interesting results concerning frontiers of efficiency between the complexity classes P and NP have been found by using different ingredients. One of the main characteri...
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In the framework of membrane computing, several interesting results concerning frontiers of efficiency between the complexity classes P and NP have been found by using different ingredients. One of the main characteristics of cell-like membrane systems is their rooted tree-like structure, where a natural parent-children membrane relationship exists, and objects can travel through the membranes. Separation rules are used as a method to obtain an exponential workspace in terms of membranes in polynomial time. Inspired by cell meiosis, objects from the original membrane are distributed between the two new membranes. In this work, P systems with evolutional symport/antiport rules and separation rules are used to give a solution to SAT, a well known NP-complete problem. One of the advantages of this solution is the use of the environment as a passive agent.
The cooperation of alliance needs a powerful agent to coordinate each other's activities. The broker agent who holds the structural holes position usually initiate this kind of governance because of the advantage ...
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The cooperation of alliance needs a powerful agent to coordinate each other's activities. The broker agent who holds the structural holes position usually initiate this kind of governance because of the advantage of information and control. This paper tied to turn the focus from sharing the cake to making a bigger cake: exploring the relationship between governance and performance of triple alliance. Basing on two dimension of external environment complex and exploration capability, we design four situations. Using the simulation experiment we extend the Aggarwal's model and explore how the governance initiated by broker agent affects the triple alliance's performance. The results show that except for the extreme case of high complex and low capability governance will lead to different performance level. The final performance depends on the reasonable matching among complex, capability and governance. At the end we discuss the contribution and the possibility of extension in the future.
Engaging in exploring multi-agent collaboration requires determining how to govern the shared activities. We examine the performance implications of selecting alternate modes of governance in multi-agent alliance rela...
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ISBN:
(纸本)9781510817371
Engaging in exploring multi-agent collaboration requires determining how to govern the shared activities. We examine the performance implications of selecting alternate modes of governance in multi-agent alliance relationships. A core set of results in this study relates to the ways in which governance structure interacts with agents' search capabilities. Alliance performance improves when the needs and supplies of coordination and exploration are matched. We find situations in which there is an inverted U relationship between governance mode and performance. At the end we discuss the contribution and the possibility of extension in the future.
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