From an information-theoretic point of view, we investigate the min-max power scheduling problem in multi-access transmission. We prove that the min-max optimal vector in a contrapolymatroid is the base with the minimal distance to the equal allocation vector. Because we can realize any base of the contra-polymatroid by time sharing among the vertices, the problem searching for the min-max opti...

Valued constraint satisfaction problems (VCSPs) are discrete optimisation problems with a Q-valued objective function given as a sum of fixed-arity functions, where Q = Q ∪ {∞} is the set of extended rationals. In Boolean surjective VCSPs variables take on labels from D = {0, 1} and an optimal assignment is required to use both labels from D. A classic example is the global mincut problem in gr...

An instance of the maximum constraint satisfaction problem (Max CSP) is a nite collection of constraints on a set of variables, and the goal is to assign values to the variables that maximises the number of satis ed constraints. Max CSP captures many well-known problems (such as Max k-SAT and Max Cut) and is consequently NP-hard. Thus, it is natural to study how restrictions on the allowed cons...

the vehicle routing problem with backhauls (vrpb) as an extension of the classical vehicle routing prob-lem (vrp) attempts to define a set of routes which services both linehaul customers whom product are to be delivered and backhaul customers whom goods need to be collected. a primary objective for the problem usually is minimizing the total distribution cost. most real-life problems have othe...

customer service level is of prime importance in today competitive world and has various dimensions with delivery quality being one of the most important ones. delivery quality has several parameters such as deliver time window options, time window size, etc. in this paper we focus on one of these parameters, namely time window setting. it has a direct impact upon customer satisfaction and busi...

We show an O∗(2k)-time polynomial space algorithm for the k-sized Graph Motif problem. We also introduce a new optimization variant of the problem, called Closest Graph Motif and solve it within the same time bound. The Closest Graph Motif problem encompasses several previously studied optimization variants, like Maximum Graph Motif, Min-Substitute, and Min-Add. Moreover, we provide a piece of ...

Background and Objectives: Visit length is a crucial aspect of patient-physician relationship that its inadequacy can negatively influence the treatment efficiency. Studies on visit length and the factors influencing it are limited in developing countries. Thus, the objective of this study was to survey this variable at provincial level, and provide data on factors affecting it.   Methods: A ...

The security performance problems of broadcast channel with an eavesdropper (BCE) have been studied for many years in the field of communication. Many articles have given the meaningful results. However, almost no consequent of an outer bound on BCE has been given by previous work, especially, no significant results has been given. So this paper proposes and proves an outer bound of BCE by usin...

We prove a strong version of the the Max-Flow Min-Cut theorem for countable networks, namely that in every such network there exist a flow and a cut that are “orthogonal” to each other, in the sense that the flow saturates the cut and is zero on the reverse cut. If the network does not contain infinite trails then this flow can be chosen to be mundane, i.e. to be a sum of flows along finite pat...

This paper presents a technique for texture segmentation in images. Providing a small template of a texture of interest results in the image being segmented into regions with similar properties and background (non-similar) regions. The core of the segmentation engine is based on the minimal cut/maximal flow algorithm in the graph representing an image. The main contribution lies in incorporatin...