We consider the online variant of facility location, in which demand points arrive one at a time and we must maintain a set of facilities to service these points. We provide a randomized onlineO(1)-competitive algorithm in the case where points arrive in random order. If points are ordered adversarially, we show that no algorithm can be constant-competitive, and provide an O(logn)-competitive a...

In the Universal Facility Location problem we are given a set of demand points and a set of facilities. The goal is to assign the demands to facilities in such a way that the sum of service and facility costs is minimized. The service cost is proportional to the distance each unit of demand has to travel to its assigned facility, whereas the facility cost of each facility i depends on the amoun...

Facility location-allocation (FLA) problem, which has been proved to be a valuable method in siting service facility, is widely used in real life, such as emergency service systems, telecommunication networks, public services, etc. However, in real-world situations, the decision maker often lack the information about the customers’ demands, which leads to the FLA problem in uncertain environmen...

First, we study the Unconstrained Fault-Tolerant Resource Allocation (UFTRA) problem (a.k.a. FTFA problem in [19]). In the problem, we are given a set of sites equipped with an unconstrained number of facilities as resources, and a set of clients with setR as corresponding connection requirements, where every facility belonging to the same site has an identical opening (operating) cost and ever...

Facility location games have been a topic of major interest in economics, operations research and computer science, starting from the seminal work by Hotelling. Spatial facility location models have successfully predicted the outcome of competition in a variety of scenarios. In a typical facility location game, users/customers/voters are mapped to a metric space representing their preferences, ...

In out last lecture, we discussed the LP Rounding technique for producing approximation algorithms. The idea behind LP Rounding is to write the problem as an integer linear program, relax its integrality restraints to efficiently solve the general linear program, and then move the LP solution to a nearby integral point in the feasible solution space. The difficulty of this process lies in the r...

proposing a robust designed facility location is one of the most effective ways to hedge against unexpected disruptions and failures in a transportation network system. this paper considers the combined facility location/network design problem with regard to transportation link disruptions and develops a mixed integer linear programming formulation to model it. with respect to the probability o...

In this article, we propose an extension of the multi-Weber facility location problem with rectilinear-distance in presence passages over a non-horizontal line barrier. For single-facility case, develop exact heuristic based on divide-and-conquer approach that outperforms alternative heuristics available literature. The multiple facilities case is solved by means application alternate-location-...

The facility location problem has occupied a central place in operations research since the early 1960's, as it models design decisions on the placement of factories, warehouses, schools, or hospitals to serve a set of customers efficiently. For an overview of previous work see the survey chapter by Cornue-jols, Nemhauser & Wolsey in [21]. Recently, it has received renewed research interest bec...

Let A be a nonempty nite subset of the plane representing the geographical coordinates of a set of demand points (towns,. . .), to be served by a facility, whose location within a given region S is sought. Assuming that the unit cost for a 2 A if the facility is located at x 2 S is proportional to dist(x; a) | the distance from x to a | and that demand of point a is given by ! a , minimizing th...