In the facility location problem usually reducing total transferring cost and time are common objectives. Designing of a network with hub facilities can improve network efficiency. In this study a new model is presented for P-hub covering location problem. In the p-hub covering problem it is attempted to locate hubs and allocate customers to established hubs while allocated nodes to hubs are in...

We consider a network design problem in which flow bifurcations are allowed. The demand data are assumed to be uncertain, and the uncertainties of demands are expressed by an uncertainty set. The goal is to install facilities on the edges at minimum cost. The solution should be able to deliver any of the demand requirements defined in the uncertainty set. We propose an exact solution algorithm ...

hub location problems are among the extensions ofclassical location problems that have numerous applications in designingtransportation, postal, and telecommunication networks. despite the evidentattention of researchers to these problems, there are few studies on designinghub networks under uncertainty and disruption. in this study, the capacitatedsingle allocation hub location problem under d...

Recent papers in the concept of Supply Chain Network Design (SCND) have seen a rapid development in applying the stochastic models to get closer to real-world applications. Regaring the special characteristics of each product, the stracture of SCND varies. In tire industry, the recycling and remanufacturing of scraped tires lead to design a closed-loop supply chain. This paper proposes a two-st...

The goals of hub location problems are finding the location of hub facilities and determining the allocation of non-hub nodes to these located hubs. In this work, we discuss the multi-modal single allocation capacitated p-hub covering problem over fully interconnected hub networks. Therefore, we provide a formulation to this end. The purpose of our model is to find the location of hubs and the ...

The optimal locating of facilities has large effects on economic benefits, providing satisfactory service and levels of customer satisfaction. One of the new topics discussed in location problems is hub location and hub facilities are subject to unpredictable disruptions. This paper proposes a nonlinear integer model for reliable single allocation hub location problem that considers backup hub,...

This paper proposes a stochastic hydro unit commitment (SHUC) model for price-taker hydropower producer in liberalized market. The objective is to maximize the total revenue of producer, including immediate revenue, future (i.e., opportunity cost), and startup shutdown cost. market price uncertainty taken into account through scenario tree. solution challenging task due its non-convex high-dime...

In this paper, we study recourse-based stochastic nonlinear programs and make two sets of contributions. The first set assumes general probability spaces and provides a deeper understanding of feasibility and recourse in stochastic nonlinear programs. A sufficient condition, for equality between the sets of feasible first-stage decisions arising from two different interpretations of almost sure...

In the context of public transportation system, improving the service quality and robustness through minimizing the average passengers waiting time is a real challenge. This study provides robust stochastic programming models for train timetabling problem in urban rail transit systems. The objective is minimization of the weighted summation of the expected cost of passenger waiting time, its va...

A computational method is developed for solving time consistent distributionally robust multistage stochastic linear programs with discrete distribution. The structure of the uncertain parameters described by a scenario tree. At each node this tree, an ambiguity set defined conditional moment constraints to guarantee consistency. This employs idea nested Benders decomposition that incorporates ...