This paper proposes a novel relief supply collaboration approach to address the issue of post-disaster relief supply-demand imbalance in emergency logistics (EL) operations. This proposed approach involves two levels ...
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This paper proposes a novel relief supply collaboration approach to address the issue of post-disaster relief supply-demand imbalance in emergency logistics (EL) operations. This proposed approach involves two levels of recursive functions: (1) a two-stage relief supplier clustering mechanism for time-varying multi-source relief supplier selection and (2) the use of stochastic dynamic programmingmodel to determine a multi-source relief supply that minimises the impact of relief supply-demand imbalance during EL response. The distinctive features of this proposed approach are to identify the potential relief suppliers and to minimise the imbalanced supply-demand impact under relief supply collaboration. Scenario design and model tests are conducted to demonstrate that relief supply collaboration with grouped relief suppliers has a significant benefit of alleviating the impact of imbalanced relief supply-demand, relative to collaboration with ungrouped ones.
One technique to coordinate the suppliers' and the producers' production plans in a supply chain is the use of delivery profiles, which provide fixed delivery frequencies for all suppliers. The selection of a ...
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One technique to coordinate the suppliers' and the producers' production plans in a supply chain is the use of delivery profiles, which provide fixed delivery frequencies for all suppliers. The selection of a delivery profile assignment has major effects on the cost efficiency and the robustness of a supply chain and thus should be performed carefully. In this work, we consider planning approaches to select delivery profiles for the case of area forwarding-based inbound logistics networks, which are commonly used in several industries to consolidate supplies in an early stage of transport. We present a two-stage stochastic mixed integer linear programmingmodel to determine robust delivery profile assignments under uncertain and infrequent demands and complex tariff systems. The model is embedded into a solution framework consisting of scenario generation and reduction techniques, a decomposition approach, a genetic algorithm, and a standard MILP solver. On the basis of an industrial case study, we show that our approach is computationally feasible and that the planning solutions obtained by our model outperform both a deterministic approach and the planning methodology prevailing in industrial practice.
We propose a bi-objective cell formation problem with demand of products expressed in a number of probabilistic scenarios. To deal with the uncertain demand of products, a framework of two-stage stochasticprogramming...
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We propose a bi-objective cell formation problem with demand of products expressed in a number of probabilistic scenarios. To deal with the uncertain demand of products, a framework of two-stage stochastic programming model is presented. The proposed model considers minimizing the sum of the miscellaneous costs (machine constant cost, expected machine variable cost, cell fixed-charge cost, and expected intercell movement cost) and expected total cell loading variation. Because of conflicting objectives, we develop a two-phase fuzzy linear programming approach for solving bi-objective cell formation problem. To show the effectiveness of the proposed approach, numerical examples are solved and the results are compared with the two existing approaches in the literature. The computational results show that the proposed fuzzy method achieves lower objective functions as well as higher satisfaction degrees.
In this work we present a stochastic programming model minimizing costs, to support the decision process of inventory policy which best satisfies the demand for food in shelters when hurricane winds are about to impac...
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Quick diagnosis is critical to stroke patients, but it relies on expensive and heavily used imaging equipment. This results in long waiting times with potential threats to the patient's life. It is important for n...
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Quick diagnosis is critical to stroke patients, but it relies on expensive and heavily used imaging equipment. This results in long waiting times with potential threats to the patient's life. It is important for neurovascular departments treating stroke patients to reduce waiting times for diagnosis. This paper proposes a reservation process of magnetic resonance imaging (MRI) examinations for stroke patients. The neurovascular department reserves a certain number of appropriately distributed contracted time slots (CTS) to ensure quick diagnosis of stroke patients. Additional MRI time slots can also be reserved by regular reservations (RTS). The problem consists in determining the contract and the control policy to assign patients to either CTS or RTS in order to reach the best compromise between the waiting times and unused CTS. Structural properties of the optimal control policy are proved by an average-cost Markov decision process (MDP) approach. The contract is determined by combining a Monte Carlo approximation approach and local search. Extensive numerical experiments are performed to show the efficiency of the proposed approach and to investigate the impact of different parameters.
Aiming at the stochastic vehicle routing problems with uncertain demand and travel time and with simultaneous pickups and deliveries, a stochasticprogrammingmodel is formulated and an improved genetic algorithm ...
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ISBN:
(纸本)9781424468126;9780769540306
Aiming at the stochastic vehicle routing problems with uncertain demand and travel time and with simultaneous pickups and deliveries, a stochasticprogrammingmodel is formulated and an improved genetic algorithm is proposed for routes optimization. Self-adaptive mechanism is introduced for amending the fitness value to overcome the premature convergence effectively and to improve the efficiency of the algorithm. The performance of the algorithm is discussed under a variety of problem settings and parameters value by the numerical experiments and sensitivity analysis. Results demonstrate that not only the proposed algorithm obtains even better results, but also it has a good robustness.
This paper considers the multi-objective linear programming problem and discusses the case in which the coefficients of the objective function are fuzzy random variables. First, the fuzzy goal is introduced into the o...
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This paper considers the multi-objective linear programming problem and discusses the case in which the coefficients of the objective function are fuzzy random variables. First, the fuzzy goal is introduced into the objective function, considering the fuzzy decision of the human decision-maker. We consider a model in which the possibility or the necessity that the objective function value achieves the fuzzy goal is maximized on the basis of fuzzy programming or possibility programming. It is noted that the possibility or necessity fluctuates stochastically, and a decision-making process based on the stochastic programming model is proposed. After modifying the problem with constraint into an equivalent deterministic problem, the convex programming problem with a parameter is introduced. Then, an algorithm is proposed in which the optimal solution is derived, combining nonlinear programming and the bisection method. (C) 2004 Wiley Periodicals, Inc.
This paper deals with multiobjective linear programming problems involving fuzzy random variable coefficients and provides new solution concepts based on M alpha-Pareto optimality and stochastic programming models. Fu...
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ISBN:
(纸本)0780392981
This paper deals with multiobjective linear programming problems involving fuzzy random variable coefficients and provides new solution concepts based on M alpha-Pareto optimality and stochastic programming models. Fuzzy goals are introduced to consider the imprecise of the decision maker's judgment for objective functions. After the formulated problem is transformed into the deterministic one, an interactive algorithm based on the reference point method is constructed to solve the deterministic problem.
This paper proposes a stochastic water quality management model which considers river flow as a random variable and optimizes waste allocation at point sources. The model is subjected to a chance constrain which can b...
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ISBN:
(纸本)0080407749
This paper proposes a stochastic water quality management model which considers river flow as a random variable and optimizes waste allocation at point sources. The model is subjected to a chance constrain which can be converted into an equivalent deterministic constrain, and then can be solved by the use of the available deterministic programming algorithm. The allowable discharge loads and degree of required removal of each point source of a river basin are optimized under various degrees of reliability, and can be employed as information for decision making to decide the most suitable treatment degree of wastewater in a river basin.
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