A robust bi-level model of the single-product multi-period network design problem is proposed for a competitive green supply chain considering pricing and inventory decisions under uncertainty and ...disruption risks. The bi-level programming approach is used through this model to demonstrate the competition among two supply chains; the leader and the follower, respectively. After modelling the competition and applying pricing decisions by defining a price-dependent demand, disruption risks are analysed through the model. The proposed model simultaneously considers demand uncertainty and disruption risks and is capable of dealing with such uncertainties by implementing resilience strategies including, inventory decisions, and having a contract with reliable suppliers. Moreover, to consider the environmental issues, controlling CO2 emissions and managing the reverse flow were added to the model. Our approach to mitigate the problem uncertainties is to use the possibilistic programming method. The Karush-Kuhan-Tucker (K-K-T) optimality conditions are deployed to make a single-level equivalent form. Since the integrated model was bi-objective, the ϵ-constraint method is implemented to make a single objective integrated model. Finally, some managerial implications are discussed through an industrial case example.
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BFBNIB, GIS, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
This paper presents a fuzzy bi-objective bi-level model with a price-dependent demand for the network design of a closed-loop supply chain in the presences of random disruptions at suppliers. The ...environmental issues resulted in considering two strategies, namely: adding a reverse flow to the supply chain and controlling the amount of CO2 emissions. In this model, the uncertain demand is assumed as a function of price offered to the customers by the supply chain and its rival. The proposed model determines outsourcing strategies, pricing decisions that maximize the total profit in such a competitive situation and minimizes the amount of CO2 emissions by production processes. A hybrid approach combining Karush–Kuhn–Tucker (K-K-T) conditions and possibilistic method was developed to solve the fuzzy bi-level model. Then the ε-constraint method is used to convert the integrated bi-objective model to a single-objective one. Finally, important managerial insights are obtained from an empirical case study of a filter industry.
•Presenting a bi-objective model for green closed-loop supply chain network design.•Considering disruption and operational risks with a fuzzy price-dependent demand.•Addressing environmental issues by minimizing CO2 emission in production process.•Applying a bi-level programming method to model Stackleberg game in the problem.•Developing a solution approach based on fuzzy programming technique.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Entropy model is the base structure of automated word categorizing. In this model, words appear consecutive frequently will place in different groups. Although this method is not correct always, in ...the most cases, obtained results simulate real situation. Because of NP-complete structure of clustering problems, the entropy model cannot be solved by an optimal algorithm, so a number of heuristic algorithms were developed to solve this problem. Some examples of these heuristics are artificial neural networks, genetic algorithms, greedy algorithms and so on. In this paper, we used a clustering ensemble method for word categorization. The method uses a new feature space generated by k-means for clustering. The results show that an improvement in categorization is obtained.
