Facility location decisions play a prominent role in strategic planning of many firms, companies and governmental organizations. Since in many real-world facility location problems, the data are subject to uncertainty, in this paper, we consider the P-center problem under uncertainty of demands. Using Bertsimas and Sim approach, we develop a robust model of the problem as an integer programming...

The unequal-areas facility layout problem is concerned with finding the optimal arrangement of a given number of non-overlapping indivisible departments with unequal area requirements within a facility. We present an improved optimization-based framework for efficiently finding competitive solutions for this problem. The framework is based on the combination of two mathematical optimization mod...

The flexibility of district heating systems can be utilized to provide ancillary services for electric power and hence the investors make profits by taking advantage arbitrage in multiple markets. This paper proposes a strategic investment scheme system participating both electricity energy reserve markets, which enables enhanced decisions installation combined heat units, pumps, thermal storag...

This study investigates the strategic scheduling of a multi-energy system (MES) in day-ahead wholesale market (DWM) as price-maker that can submit offers/bids to purchase/sell energy. In this regard, proposed model presents bi-level optimization problem, wherein upper-level is cost minimization objective MES, while lower-level considered operator (WMO) clears according received from producers/c...

in the field of health losses resulting from failure to establish the facilities in a suitable location and the required number, beyond the cost and quality of service will result in an increase in mortality and the spread of diseases. so the facility location models have special importance in this area. in this paper, a successively inclusive hierarchical model for location of health centers i...

Increasing intermittent renewable energy sources (RESs) intensifies the imbalance between demand and generation, entailing diversification of deployment electrical storage systems (ESSs). A large-scale biogas plant (LBP) installed with heating devices (BES) usually exhibits a storage-like characteristic accommodating an increasing penetration level RES in rural areas, which is addressed this pa...

This paper proposes a bi-level stochastic optimization problem (a Stackelberg game) to generate optimal bids for a profit maximizing hydropower producer and presents a mathematical approach to solve it. The first level represents the strategically acting hydropower producer also called a Stackelberg leader, while the second level represents the transmission system operator (TSO) also called a S...

Recent work on the location of perinatal facilities in the municipality of Rio de Janeiro resulted in the development of an uncapacitated, three-level hierarchical model. An important issue that arose during the course of the research was the need to include some form of capacity constraints into the model, especially in the higher, resource intensive level of the hierarchy. This need was felt ...

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...