NP-Hard Network Upgrading Problems+
نویسندگان
چکیده
University of Florida Technical Report 91-29 Abstract Graphs with delays associated with their edges are often used to model communication and signal flow networks. Network performance can be improved by upgrading the network vertices. Such an improvement reduces the edge delays and comes at a cost. We study different formulations of this network performance improvement problem and show that these are NP-hard.
منابع مشابه
Lowering eccentricity of a tree by node upgrading
The eccentricity lowering problem is to reduce the eccentricity of a communication network within a given bound, by upgrading some nodes (i.e., shrinking the lengths of the edges linking to such nodes), where we want to minimize the required cost. We consider two types of node-upgrading strategies; i.e., the continuous upgrading and the discrete upgrading, where the improvement under the first ...
متن کاملUpgrading arcs to minimize the maximum travel time in a network
In transportation and telecommunication systems, the performance of the underlying network can often be improved by upgrading some of the arcs in the network. If an arc is upgraded, the travel time along this arc is reduced by a discount factor α, 0 ≤ α < 1. With respect to different minimax network objectives, we define a series of problems that involve finding the best q arcs in a network to ...
متن کاملProblem Hardness Result Approximation ResultBSTP
Several problems arising in the areas of communication networks and VLSI design can be expressed in the following general form: Enhance the performance of an underlying network by upgrading some of its nodes. We investigate one such problem. Consider a network where nodes represent processors and edges represent bidirectional communication links. The processor at a node v can be upgraded at an ...
متن کاملFinding Approximate Solutions to NP-Hard Problems by Neural Networks is Hard
Finding approximate solutions to hard combinatorial optimization problems by neu-ral networks is a very attractive prospect. Many empirical studies have been done in the area. However, recent research about a neural network model indicates that for any NP-hard problem the existance of a polynomial size network that solves it implies that NP=co-NP, which is contrary to the well-known conjecture ...
متن کاملParallelizing Assignment Problem with DNA Strands
Background:Many problems of combinatorial optimization, which are solvable only in exponential time, are known to be Non-Deterministic Polynomial hard (NP-hard). With the advent of parallel machines, new opportunities have been emerged to develop the effective solutions for NP-hard problems. However, solving these problems in polynomial time needs massive parallel machines and ...
متن کامل