Papers by Reza Tavakkoli-Moghaddam
Scientia Iranica, Sep 30, 2020
This paper presents a robust location-allocation planning problem for emergency relief in a disas... more This paper presents a robust location-allocation planning problem for emergency relief in a disaster situation, which is formulated as a robust optimization model. It is a multi-objective, multi-commodity, multi-vehicle and multi-level logistics model considering injury variety through service prioritizing for more injuries and considering unmet demand of particular item type in various damaged areas, public donation of different relief goods, using capacitated medical centers and emergency centers regarding damage type and capacitated relief distribution centers and disaster management centers. This a non-linear mixed-integer programming model that simultaneously optimizes three objectives; i.e., maximizing service fairness to damaged areas, maximizing fair commodity disaster management, and minimizing the total logistics cost. To solve such a hard problem, a non-dominated sorting genetic algorithm (NSGA-II) is developed and the Taguchi method is applied to adjust its parameters. The ε-constraint method is used for the evaluation of the proposed algorithm performance. For more accurate validation, three comparison metrics, including diversification, spacing and mean ideal distance, are used. The results verify the algorithm's effectiveness in a reasonable computational time. Eventually, to examine the applicability of the presented model and the proposed algorithm, a case study is analyzed in the area located in the north of Iran, known with historical earthquake records and aggregated active faults.
International Journal of Nonlinear Analysis and Applications, 2020
Many organizations (including banks) have a multi-step process and their operations are a continu... more Many organizations (including banks) have a multi-step process and their operations are a continuous process in successive periods. The Taguchi method is an efficient way to optimize a single quality response. However, in practice most products / processes have more than one qualitative response. Recently, the multi-answer question in the Taguchi method has attracted considerable research attention. Therefore, this study presents an efficient approach to multi-response problem solving in Taguchi method using hybrid data envelopment analysis (DEA) model. Each experiment is discussed in the Taguchi Orthogonal Array (OA) as a decision unit (DMU) with multiple input and / or output response sets. Each DMU is evaluated by a hybrid model. The sequential DUM productivity value is then used to decide the optimal factor levels for the multi-response problem. The computational results showed that the proposed approach provides the most anticipated improvement in PCA, DEA (DEAR) and other available techniques. The suggestion may be of great help to managers in solving multi-response problems in production programs in the Taguchi method.
In this paper, we present a new mixed-integer linear goal programming (MILGP) model for a fuzzy s... more In this paper, we present a new mixed-integer linear goal programming (MILGP) model for a fuzzy singlesource capacitated facility location problem (F-SSCFLP), in which demands are considered as triangular fuzzy values and capacity of facilities are fuzzy constraints. At first, the basic fuzzy model for the given problem is presented. Then, utilizing goal programming (GP) approach and fuzzy principals the proposed MILGP model is introduced. Accordingly, considering a certain acceptable deviation from capacities and demands, the cost of selecting facilities and serving the demand points is minimized. Finally, to investigate the effectiveness of the presented model some large-sized problems generated randomly and all of them are solved globally in a reasonable time.
This paper considers a non-preemptive open shop scheduling problem (OSSP), in which machines are ... more This paper considers a non-preemptive open shop scheduling problem (OSSP), in which machines are not available to process jobs on known periodic interval times resulted from periodic service repair, rest period, and so on. Asymmetric transportation time between machines is considered, which can be different from one job to another. The objective is to minimize the weighted mean completion time (WMCT). Since the problem is categorized into NP-hard class, two meta-heuristic algorithms including genetic algorithm (GA) and differential evolution (DE) are proposed. Meanwhile, a new initial population is introduced, which significantly improves the performance of the algorithms. Finally, the performance of the algorithms is validated through some large-sized instances and the results are discussed.
Journal of Industrial and Systems Engineering, Nov 1, 2019
This paper proposes a modified non-dominated sorting genetic algorithm (NSGA-II) for a bi-objecti... more This paper proposes a modified non-dominated sorting genetic algorithm (NSGA-II) for a bi-objective location-allocation model. The purpose is to define the best places and capacity of the distribution centers as well as to allocate consumers, in such a way that uncertain consumers' demands are satisfied. The objectives of the mixed-integer nonlinear programming (MINLP) model are to (1) minimize the total cost of the network and (2) maximize the utilization of distribution centers. To solve the problem, a fuzzy modified NSGA-II with local search is proposed. To illustrate the results, computational experiments are generated and solved. The experimental results demonstrate that the performance metrics of the fuzzy modified NSGA-II is better than the original NSGA-II.
International journal of engineering. Transactions A: basics, Jul 1, 2019
Regarding the development of distribution systems in the recent decades, fuel consumption of truc... more Regarding the development of distribution systems in the recent decades, fuel consumption of trucks has increased noticeably, which has a huge impact on greenhouse gas emissions. For this reason, the reduction of fuel consumption has been one of the most important research areas in the last decades. The aim of this paper is to propose a robust mathematical model for a variant of a vehicle routing problem (VRP) to optimize sales of distributers, in which the time of distributor service to customers is uncertain. T o solve the model precisely, the improved differential evolution (IDE) algorithm is used and obtained results were compared with the result of a particle swarm optimization (PSO) algorithm. The results indicate that the IDE algorithm is able to obtain better solutions in solving large-sized problems; however, the computational time is worse than PSO.
Journal of Industrial and Systems Engineering, Nov 30, 2019
International Journal of Transportation Engineering, Jul 1, 2019
This paper presents a new model for a closed-loop supply chain problem under uncertainty. This mo... more This paper presents a new model for a closed-loop supply chain problem under uncertainty. This model considers production, distribution, collection, recycling and disposal of items simultaneously. Because of the increased importance of the environmental factors, this model focuses on the revers flow of the supply chain and considers different types of technology for recycling centers. The model aims to minimize the establishment cost of centers, shipment cost, holding cost, collection cost and recycling cost. To face with uncertain parameters, a credibilitybased possibilistic programming method is applied. Then, a social engineering optimizer algorithm is proposed to solve the problem efficiency. To validate the model and proposed algorithm, the results are compared with the results of GAMS. In addition, they prove the superiority of the proposed algorithm over a genetic algorithm to deal with problems and find better results in less running time. Finally, the behavior of the model is assessed by changing the values of parameters and the results are reported.
Journal of Industrial and Systems Engineering, Nov 16, 2018
This paper addresses a closed-loop supply chain network design problem, in which two different su... more This paper addresses a closed-loop supply chain network design problem, in which two different supply chains compete on retail prices by defining a pricedependent demand function. So, the model is formulated in a bi-level stochastic form to demonstrate the Stackelberg competition and associated uncertainties more precisely. Moreover, it is capable of considering random disruptions in the leader supply chain while incorporating the inventory, pricing, location and allocation decisions. Afterwards, having a contract with reliable suppliers is examined to resist the consequent results of disruption in the supply process. Additionally, the sharing strategy with new resilient distribution centers is used for tackling disruption risks at distribution centers. Furthermore, after integrating the proposed bi-level model into an integrated equivalent form by using the Karush-Kuhn-Tucker (KKT) transformation method, the conditional value at risk (CVaR) measure is used to handle the considered uncertainties. Finally, a real industrial case of a filter company is applied to obtain numerical results and the performance of the stochastic model is investigated by several test problems to arrive in helpful managerial insights.
International Journal of Transportation Engineering, Apr 1, 2019
In each time period, the passengers' demand for each route is finite and airlines compete for ear... more In each time period, the passengers' demand for each route is finite and airlines compete for earning more profits. The complex competition among airlines causes some problems, such as complicating flight planning and increasing empty seats for some routes. These problems increase air pollution and fuel consumption. To solve these problems, this research studies the cooperation of the airlines with game theory and sustainable development app.roaches. To investigate the issue, the three steps are suggested as introducing the components of the multi-attribute game theory to the multi-objective model, modeling multi-objective formulation with a sustainable development app.roach, and solving the model by a multiobjective method. Pay-off functions are to maximize the profit of airlines, minimize the total difference among the No.s of flier passengers and their demand on all routes and all flight times, and minimize empty seats. All the above-mentioned objectives present economic, social, and environmental aspects of sustainable development. The results of the airline cooperation model are compared with the information about non-cooperation collected from airlines in the current form. The cooperation of airlines can improve the objective functions and the sustainable development app.roach. This research can be used to help airlines in identifying the role of cooperation in air transportation.
International Journal of Research, Nov 1, 2016
International Journal of Research, Dec 1, 2014
Selecting the most appropriate and optimal facility location for a new organization or expansion ... more Selecting the most appropriate and optimal facility location for a new organization or expansion of an existing location is an important strategic issue. The location, which results in higher economic benefits through increased productivity and good distribution network, is the best location. It is necessary to compare the performance characteristics in a decisive way when a choice is to be made from among several alternative facility locations. While the facility location selection problem includes multiple conflicting criteria and a finite set of potential candidate alternatives, different multi-criteria decision making (MCDM) methods can be effectively applied to solve such type of problem. In this paper, we apply three MCDM methods on a facility location selection problem and their relative ranking performances are compared. Because of disagreement in the ranks obtained by the three different MCDM methods, a final ranking method based on REGIME is also proposed to facilitate the decision making process. Then, the results of this study are compared by the results of the same study.
Advances in Industrial Engineering, Jun 22, 2017
International Journal of Engineering, Transactions B: Applications, Mar 10, 2017
In this paper, to cope with the stochastic dynamic (or multi-period) problem, two new quadratic a... more In this paper, to cope with the stochastic dynamic (or multi-period) problem, two new quadratic assignment-based mathematical models corresponding to the dynamic and static approaches are developed. The product demands are presumed to be dependent uncertain variables with normal distribution having known expectation, variance, and covariance that change from one period to the next one, randomly. In the proposed models, time value of money and the decision maker's attitude about uncertainty are also considered. The models are verified and validated by performing statistical, robustness and stability analyses carried out by using design of experiment and benchmark methods. In addition, the effect of dependency of product demands and interest rate on the total cost function of the proposed models has also been investigated. The dynamic programming algorithm, which is coded in Matlab, is used to solve the models. The main conclusions are as follows: (i) the dynamic layout behaves like static layout in the case of low facility rearrangement cost; (ii) unlike the static layout, the robustness and stability of the dynamic layout depend on the facility rearrangement cost; (iii) the decision maker's attitude about uncertainty affects the robustness of each of the dynamic and static layouts; (iv) considering non-zero interest rate leads to increase in the total cost over the range of uncertainty; and (v) regarding both the dynamic and the static layouts, the effect of dependency of product demands on the total cost is a function of the decision maker's defined percentile level.
Journal of Industrial and Systems Engineering, Apr 1, 2012
In this paper, we study an integrated logistic system where the optimal location of depots and ve... more In this paper, we study an integrated logistic system where the optimal location of depots and vehicles routing are considered simultaneously. This paper presents a new mathematical model for a multi-objective capacitated location-routing problem with a new set of objectives consisting of the summation of economic costs, summation of social risks and demand satisfaction score. A new multi-objective adaptative simulated annealing (MOASA) is proposed to obtain the Pareto solution set of the presented model according to the previous studies. We also apply three multi-objective meta-heuristic algorithms, namely MOSA, MOTS and MOAMP, on the simulated data in order to compare the proposed procedure performance. The computational results show that our proposed MOASA outperforms the three foregoing algorithms.
International Journal of Engineering, Transactions B: Applications, Nov 1, 2015
In this paper, a quaternion firefly algorithm is utilized to solve a multi-row facility layout de... more In this paper, a quaternion firefly algorithm is utilized to solve a multi-row facility layout design problem with the objective of minimizing the total cost of transportation. A quaternion firefly algorithm takes the motion of the firefly as a quaternion one. Consequently, the solution space is explored more accurately and the answers are of higher quality. That is, the answers are considerably better than those obtained by standard firefly algorithms. Given the necessity to cut the costs of transferring materials in the facility layout design, a layout is adopted to examine the performance of the algorithm and the solutions from the proposed algorithm are compared with those of CRAFT software, entropy algorithm, and genetic algorithm with that of a heuristic process. The results show better performance of the proposed algorithm comparing other algorithms under examination.
International Journal of Industrial Mathematics, Apr 1, 2015
International Journal of Transportation Engineering, 2015
Today, transportation of hazardous materials (i.e., hazmat) is a very important issue for researc... more Today, transportation of hazardous materials (i.e., hazmat) is a very important issue for researchers due to the risk of this transit, which should be considered for development of industries and transportation. Therefore, a model that is useful should consider the risk and damage to humanitarian reality and applicability of the model are also very important. In this paper, a bi-objective model is presented for routing rail-truck intermodal terminals with the cost and risk as objective functions by considering three sets of the effective factors that lead to hazardous materials transportation accidents in favor of sustainability. Additionally, a fuzziness concept is considered in the presented literature is used. Finally, it is concluded that in this work a reality and sustainable model is suitable for hazmat transportation.
South African Journal of Industrial Engineering, May 1, 2021
Road accidents, as one of the causes of mortality in human societies, have many adverse social an... more Road accidents, as one of the causes of mortality in human societies, have many adverse social and economic consequences. Various measures can improve the safety of travel. One of them is to find appropriate location of relief infrastructures. The proper pre-positioning of relief chains locations can decrease road users' fatalities. Thus this paper presents a multi-objective mathematical model to the pre-positioning of a relief chain for road accidents. Then the model is solved by a non-dominated sorting genetic algorithm. Factors that affect the location of relief chains are identified using a multi-attribute decision-making method. Finally, potential locations are proposed for the relief chain locations.
International Journal of Nonlinear Analysis and Applications, Feb 1, 2021
A Location-Arc Routing Problem (LARP) is a practical problem, while a few mathematical programmin... more A Location-Arc Routing Problem (LARP) is a practical problem, while a few mathematical programming models have been considered for this problem. In this paper, a mixed non-linear programming model is presented for a multi-period LARP with the time windows under demand uncertainty. The time windows modeling in the arc routing problem is rarely. To the best our knowledge, it is the first time that the robust LARP model is verified and an optimal solution is presented for it. For this purpose, the CPLEX solver is used for solving the treasury locate problems of a bank as a case study. These problems are node-based with close nods and can be transformed into arc-based. Therefore, the method LRP and LARP models can be used to solve these problems. The comparing results of the LRP and LARP models prove that the LARP has a better performance regarding timing and optimal solution. Furthermore, comparing the results of deterministic and robust LARP models for this case study shows the validity of the robust optimization approach.
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Papers by Reza Tavakkoli-Moghaddam