In this paper, the problem of scheduling crane -operated warehouses in a triangle stacking style is investigated. In a steel supply chain, warehouses play a significant role in establishing a connection between the pr...
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In this paper, the problem of scheduling crane -operated warehouses in a triangle stacking style is investigated. In a steel supply chain, warehouses play a significant role in establishing a connection between the producer and the customers. Therefore, improving their performance results in a competitive advantage in the supply chain. One of the challenges of steel coil warehouses is the selection of outgoing coils out of the candidate coils for retrieval. Despite its importance, this problem has not been investigated in the studies relevant to steel coil warehouses. In this study, in addition to the selection of outgoing coils, sequencing of the operations on the incoming, outgoing, and blocking coils, location assignment to the incoming and blocking coils, and crane scheduling are considered in an integrated manner. First, a mixed integer linear programming model is proposed. Further, a Greedy heuristic algorithm and two metaheuristics are developed to solve large -sized instances of the problem. Metaheuristics include a Greedy Randomized Adaptive Search Procedure (GRASP) and a hybrid algorithm that combines antcolonysystem with the GRASP (ACS -GRASP). Finally, performances of the proposed algorithms are compared over randomly generated instances as well as instances which are generated based on the real data obtained from Isfahan's Mobarakeh Steel Company. To conduct this analysis, various performance evaluation metrics are applied. Computational results indicate that ACS -GRASP converges slower than GRASP, but is more reliable and efficient. On the other hand, in large -sized instances, the Greedy algorithm runs extremely fast and can find solutions which are comparable to the metaheuristic solutions.
Continuous line drawing (CLD) is a technique used in the field of art, in which the pen does not leave the paper until the sketch is completed. In this study, a novel technique, k-continuous line drawing (kCLD), is pr...
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Continuous line drawing (CLD) is a technique used in the field of art, in which the pen does not leave the paper until the sketch is completed. In this study, a novel technique, k-continuous line drawing (kCLD), is proposed;this technique enables a visual image to comprise k closed non-intersecting lines. k-CLD involves the following challenges: 1) partitioning the target image into k regions, 2) stippling each region without distorting the target image, and 3) connecting the stippled dots in each region using a single closed, non-intersecting line. This study identifies and implements efficient algorithms to produce high-quality k-CLDs. Further, an improvement to the graph-based image segmentation algorithm has been proposed using the Minkowski distance to evaluate dissimilarity difference and demonstrated its effectiveness to partition the target image into k regions. Next, well-spaced stippled dots were generated in each region using a weighted Voronoi diagram. Finally, the stippled dots were connected by a single non-intersecting line, obtained by solving a traveling salesman problem (TSP) in each region. The meta heuristic to solve the TSP was an ant colony system algorithm. The proposed methodologies were tested on a wide variety of images to demonstrate their effectiveness and efficiency. (C) 2017 Elsevier B.V. All rights reserved.
Production scheduling problems and traditional differential evolution(DE) are analyzed in this paper. Taking the minimum of total completion time as the objective function of production scheduling, a production schedu...
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Production scheduling problems and traditional differential evolution(DE) are analyzed in this paper. Taking the minimum of total completion time as the objective function of production scheduling, a production scheduling model is established for batch processes in process industry. Considering that the performance of the traditional DE algorithm is sensitive to the parameter settings, an adaptive control evolution strategy is used to control the parameter scale factor F and crossover probability CR to solve the problem of parameter settings. Taking a practical production problem as a scheduling example, the established model and adaptive DE algorithm are applied to implement the production scheduling simulation. The simulation results show that compared with the antcolonysystem(ACS) algorithm, the adaptive DE algorithm is effective and feasible.
This paper considers the vehicle routing problem with time windows where the uncertainties of travel times are modeled with possibility distributions. A possibilistic programming model is designed for the problem. Fur...
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ISBN:
(纸本)9781424469208
This paper considers the vehicle routing problem with time windows where the uncertainties of travel times are modeled with possibility distributions. A possibilistic programming model is designed for the problem. Furthermore, an ant colony system algorithm is developed to solve the proposed model. Necessity measure is used to gain knowledge about the feasibility of generated solutions when they are realized. Finally, numerical examples are given to show the effectiveness and usefulness of the algorithm.
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