decentralization allows channel members to make their decisions, independently. in this decentralized channels, members may have different power to make its decisions. hence, decisions of each member may influence on the other members’ decisions. to model such situations, bi-level programming models are useful. in this study, a supply chain including one manufacturer and multiple competitive re...

Bat inspired (BI) algorithm is a recently developed metaheuristic optimization technique inspired by echolocation behavior of bats. In this study, the BI algorithm is examined in the context of discrete size optimization of steel frames designed for minimum weight. In the optimum design problem frame members are selected from available set of steel sections for producing practically acceptable ...

With the continuous promotion of “dual carbon” idea, future power generation will rely heavily on renewable energy sources. As an effective utilization form clean sources, it is positive significance to study trading strategy microgrids in intelligent distribution system under influence carbon quota. In this research, a bi-level optimization method used build model distribution-side market, wit...

In this paper, a location allocation (LA) problem in construction and demolition (C&D) waste management (WM) is studied. A bi-level model for this problem under a fuzzy random environment is presented where the upper level is the governments who sets up the processing centers, and the lower level are the administrators of different construction projects who control C&D waste and the after treat...

In this paper, bi-level linear programming problem with multiple objectives at each level in intuitionistic fuzzy environment is studied and solved. In this problem, technological coefficients and resources are characterized by intuitionistic fuzzy numbers having linear membership and non-membership function. Intuitionistic fuzzy efficient solution is computed for the upper level by the propose...

graph theory based methods are powerful means for representing structural systems so that their geometry and topology can be understood clearly. the combination of graph theory based methods and some metaheuristics can offer effective solutions for complex engineering optimization problems. this paper presents a charged system search (css) algorithm for the free shape optimizations of thin-wall...