j∈Si d(j, F )    , where for any F ⊆ V , d(j, F ) = minf∈F d(j, f). This is a “min-max” or “robust” version of the k-median problem. Note that in contrast to the recent papers on robust and stochastic problems, we have only one stage of decisionmaking where we select a set of k facilities to open. Once a set of open facilities is fixed, each client in the uncertain client-set connects to the...

Decision-making concerning thelocation of critical resource on the geographical network is important in many industries.In the healthcare system,these decisions include location of emergency and preventive care. The decisions of location play a crucial role due to determining the travel time between supply and de//////mand points and response time in emergencies.Organs are considered as highly ...

A stochastic multiproduct capacitated facility location problem involving a single supplier and multiple customers is investigated. Due to the stochastic demands, a reasonable amount of safety stock must be kept in the facilities to achieve suitable service levels, which results in increased inventory cost. Based on the assumption of normal distributed for all the stochastic demands, a nonlinea...

Determining the optimal location of facilities to serve a spatially disnersed set of customers has been an increasingly active research area during the past twenty years. Many systems whose facilities are to be located operate in a stochastic environment, with uncertainties associated with the arrival time, location and service requirements of each customer. Facilities having finite service cap...

Simulation modelling is an important tool for exploring and reasoning about complex systems. Many supporting languages are available. Commonly occurring features of these languages are constructs capturing concepts such as process, resource, and location. We describe a mathematical framework that supports a modelling idiom based on these core concepts, and which adopts stochastic methods for re...

Abstract. Motivated by the concept of “location uncertainty”, initially introduced in Mémin (2014), a scheme is sought to perturb “location” state variable at every forecast time step. Further considering Brenier's theorem (Brenier, 1991), asserting that difference two positive density fields on same domain can be represented transportation map, we demonstrate perturbations consistently define ...

We study a model of competition among nomadic agents for timevarying and location-specific resources, arising in crowd-sourced transportation services, online communities, and traditional location-based economic activity. This model comprises a group of agents and a single location endowed with a dynamic stochastic resource process. Periodically, each agent derives a reward determined by the lo...

In the past two decades, due to study on matrix theory and some engineering background problems, many scholars dedicated to special matrix , and obtained some important and valuable results (TingZhu, 2007 Yigeng Huang, 1994). But in combination matrix theory, combinatorics, probability theory (especially Markov chain), mathematical economics and reliability theory etc. areas there is a special ...

In this article we focus on approximation algorithms for facility location problems with subadditive costs. As examples of such problems, we present two facility location problems with stochastic demand and exponential servers, respectively inventory. We present a (1 + , 1)-reduction of the facility location problem with subadditive costs to a soft capacitated facility location problem, which i...

In this article, a capacitated location allocation problem is considered in which the demands and the locations of the customers are uncertain. The demands are assumed fuzzy, the locations follow a normal probability distribution, and the distances between the locations and the customers are taken Euclidean and squared Euclidean. The fuzzy expected cost programming, the fuzzy β-cost minimizatio...