The Experts below are selected from a list of 72060 Experts worldwide ranked by ideXlab platform
Mohammad A Hoque - One of the best experts on this subject based on the ideXlab platform.
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a Heuristic Solution technique to attain the minimal total cost bounds of transporting a homogeneous product with varying demands and supplies
European Journal of Operational Research, 2014Co-Authors: Z A M S Juman, Mohammad A HoqueAbstract:Abstract Transportation of a product from multi-source to multi-destination with minimal total transportation cost plays an important role in logistics and supply chain management. Researchers have given considerable attention in minimizing this cost with fixed supply and demand quantities. However, these quantities may vary within a certain range in a period due to the variation of the global economy. So, the concerned parties might be more interested in finding the lower and the upper bounds of the minimal total costs with varying supplies and demands within their respective ranges for proper decision making. This type of transportation problem has received attention of only one researcher, who formulated the problem and solved it by LINGO. We demonstrate that this method fails to obtain the correct upper bound Solution always. Then we extend this model to include the inventory costs during transportation and at destinations, as they are interrelated factors. The number of choices of supplies and demands within their respective ranges increases enormously as the number of suppliers and buyers increases. In such a situation, although the lower bound Solution can be obtained methodologically, determination of the upper bound Solution becomes an NP hard problem. Here we carry out theoretical analyses on developing the lower and the upper bound Heuristic Solution techniques to the extended model. A comparative study on Solutions of small size numerical problems shows promising performance of the current upper bound technique. Another comparative study on results of numerical problems demonstrates the effect of inclusion of the inventory costs.
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an alternative Heuristic Solution technique for efficient management of the serial supply chain
International Journal of Business Innovation and Research, 2008Co-Authors: Mohammad A Hoque, S K GoyalAbstract:The serial supply chain management has received considerable attention in the literature. A few years back, the literature had been enriched by the presentation of serial supply chain models, both for single and sequence dependent multicomponent supply chain management, and their Heuristic Solution procedures. This paper demonstrates that the sequencing rule applied to select the appropriate sequence of products in determining minimal total cost does not meet the purpose. In addition, it finds that though the author presented generalised models, the Solution procedures are restricted to a particular case. In this paper, the models are reorganised and alternative generalised Heuristic Solution procedures are presented so that they can never be worse than the original one. Then, we carry out a comparative study of our methods with the original ones on two numerical problems (illustrated in the original paper) to show cost reductions with reduced cycle times by our method.
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a Heuristic Solution procedure for an integrated inventory system under controllable lead time with equal or unequal sized batch shipments between a vendor and a buyer
International Journal of Production Economics, 2006Co-Authors: Mohammad A Hoque, S K GoyalAbstract:Abstract This paper develops a Heuristic Solution procedure to minimize the total cost of setup or ordering, inventory holding and lead-time crashing for an integrated inventory system under controllable lead-time between a vendor and a buyer. Recently, this system has been studied with an extra safety stock over the year and a technique to attain a minimum cost Solution has been developed. In this paper, the shortcoming of this technique in providing minimum cost Solution is demonstrated. In addition, an alternative generalized model, based on equal and unequal sized batch shipments of a lot from the vendor to the buyer, is developed. Restricting the safety stock for the time of satisfying demand by the lot, a number of properties that the optimal Solution should satisfy are developed. Based on these properties an algorithm giving the optimal Solution is then derived. The potential value of transferring the lot with equal and unequal sized batches in reducing the total annual cost is illustrated with the Solution of two numerical examples.
Travis S Waller - One of the best experts on this subject based on the ideXlab platform.
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bi level programming formulation and Heuristic Solution approach for dynamic traffic signal optimization
Computer-aided Civil and Infrastructure Engineering, 2006Co-Authors: Dazhi Sun, Rahim F Benekohal, Travis S WallerAbstract:: Although dynamic traffic control and traffic assignment are intimately connected in the framework of Intelligent Transportation Systems (ITS), they have been developed independent of one another by most existing research. Conventional methods of signal timing optimization assume given traffic flow pattern, whereas traffic assignment is performed with the assumption of fixed signal timing. This study develops a bi-level programming formulation and Heuristic Solution approach (HSA) for dynamic traffic signal optimization in networks with time-dependent demand and stochastic route choice. In the bi-level programming model, the upper level problem represents the decision-making behavior (signal control) of the system manager, while the user travel behavior is represented at the lower level. The HSA consists of a Genetic Algorithm (GA) and a Cell Transmission Simulation (CTS) based Incremental Logit Assignment (ILA) procedure. GA is used to seek the upper level signal control variables. ILA is developed to find user optimal flow pattern at the lower level, and CTS is implemented to propagate traffic and collect real-time traffic information. The performance of the HSA is investigated in numerical applications in a sample network. These applications compare the efficiency and quality of the global optima achieved by Elitist GA and Micro GA. Furthermore, the impact of different frequencies of updating information and different population sizes of GA on system performance is analyzed.
Sascha Herpers - One of the best experts on this subject based on the ideXlab platform.
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abcβ a Heuristic for dynamic capacitated lot sizing with random demand under a fill rate constraint
International Journal of Production Research, 2010Co-Authors: Horst Tempelmeier, Sascha HerpersAbstract:This paper deals with the dynamic multi-item capacitated lot-sizing problem (CLSP) with random demand over a finite discrete time horizon. Unfilled demands are backordered. It is assumed that a fill rate constraint is in effect. We propose a Heuristic Solution procedure called ABC β that extends the A/B/C Heuristic introduced by Maes and Van Wassenhove for the deterministic CLSP to the case of random demands.
S K Goyal - One of the best experts on this subject based on the ideXlab platform.
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an alternative Heuristic Solution technique for efficient management of the serial supply chain
International Journal of Business Innovation and Research, 2008Co-Authors: Mohammad A Hoque, S K GoyalAbstract:The serial supply chain management has received considerable attention in the literature. A few years back, the literature had been enriched by the presentation of serial supply chain models, both for single and sequence dependent multicomponent supply chain management, and their Heuristic Solution procedures. This paper demonstrates that the sequencing rule applied to select the appropriate sequence of products in determining minimal total cost does not meet the purpose. In addition, it finds that though the author presented generalised models, the Solution procedures are restricted to a particular case. In this paper, the models are reorganised and alternative generalised Heuristic Solution procedures are presented so that they can never be worse than the original one. Then, we carry out a comparative study of our methods with the original ones on two numerical problems (illustrated in the original paper) to show cost reductions with reduced cycle times by our method.
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a Heuristic Solution procedure for an integrated inventory system under controllable lead time with equal or unequal sized batch shipments between a vendor and a buyer
International Journal of Production Economics, 2006Co-Authors: Mohammad A Hoque, S K GoyalAbstract:Abstract This paper develops a Heuristic Solution procedure to minimize the total cost of setup or ordering, inventory holding and lead-time crashing for an integrated inventory system under controllable lead-time between a vendor and a buyer. Recently, this system has been studied with an extra safety stock over the year and a technique to attain a minimum cost Solution has been developed. In this paper, the shortcoming of this technique in providing minimum cost Solution is demonstrated. In addition, an alternative generalized model, based on equal and unequal sized batch shipments of a lot from the vendor to the buyer, is developed. Restricting the safety stock for the time of satisfying demand by the lot, a number of properties that the optimal Solution should satisfy are developed. Based on these properties an algorithm giving the optimal Solution is then derived. The potential value of transferring the lot with equal and unequal sized batches in reducing the total annual cost is illustrated with the Solution of two numerical examples.
Thobias Sando - One of the best experts on this subject based on the ideXlab platform.
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exact and Heuristic Solution algorithms for efficient emergency evacuation in areas with vulnerable populations
International journal of disaster risk reduction, 2019Co-Authors: Maxim A Dulebenets, Junayed Pasha, Olumide F Abioye, Masoud Kavoosi, Eren Erman Ozguven, Ren Moses, Walter R Boot, Thobias SandoAbstract:Abstract Proper emergency evacuation planning is a key to ensure safety and efficiency of transportation networks in the event of approaching natural hazards. A sound evacuation plan can save human lives and avoid congestion. In order to develop effective emergency evacuation plans, this study presents a mixed-integer programming model that assigns individuals, including vulnerable population groups, to emergency shelters through evacuation routes during the available time periods. The objective of the mathematical model is to minimize the total travel time of individuals leaving an evacuation zone. Unlike many emergency evacuation models presented in the literature, the proposed mathematical model directly accounts for the effects of socio-demographic characteristics of evacuees, evacuation route characteristics, driving conditions, and traffic characteristics on the travel time of evacuees. An exact optimization approach and a set of Heuristic approaches are applied to yield Solutions for the developed model. The numerical experiments are conducted for emergency evacuation of Broward County (Florida, United States). The results show that the exact optimization approach cannot tackle the large-size problem instances. On the other hand, the proposed Heuristic algorithms are able to provide good-quality Solutions within a reasonable computational time. Therefore, the developed mathematical model and Heuristic algorithms can further assist the appropriate agencies with efficient and timely emergency evacuation planning.