• Journal of the Korean Operations Research and Management Science Society
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• v.19 no.3
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• pp.219-233
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• 1994

A fixed k-coloring problem is introduced and dealt with by efficient heuristic algorithms. It is shown that the problem can be transformed into the graph partitioning problem. Initial coloring and improving methods are proposed for problems with and with and without the size restriction. Algorithm Move, LEE and OEE are developed by modifying the Kernighan-Lin's two way uniform partitioning procedure. The use of global information in the selection of the node and the color set made the proposed algorithms superior to the existing method. The computational result also shows that the superiority does not sacrifice the time demand of the proposed algorithms.

• Journal of Korean Institute of Industrial Engineers
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• v.32 no.2
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• pp.98-103
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• 2006

In this research, the single machine capacitated lot-sizing and scheduling problem with sequence- dependent setup costs and setup times (CLSPSD) is considered. This problem is the extension of capacitated lot-sizing and scheduling problem (CLSP) with an additional assumption on sequence-dependent setup costs and setup times. The objective of the problem is minimizing the sum of production costs, inventory holding costs and setup costs satisfying customers' demands. It is known that the CLSPSD is NP-hard. In this paper, the MIP formulation is presented. To handle the problem more efficiently, a conceptual model is suggested, and one of the well-known meta-heuristics, the simulated annealing approach is applied. To illustrate the performance of this approach, various instances are tested and the results of this algorithm are compared with those of the CLPEX. Computational results show that this approach generates optimal or nearly optimal solutions.

• Steel and Composite Structures
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• v.14 no.5
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• pp.431-451
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• 2013

The Big Bang-Big Crunch (BB-BC) optimization algorithm is developed for optimal design of non-linear steel frames with semi-rigid beam-to-column connections. The design algorithm obtains the minimum total cost which comprises total member plus connection costs by selecting suitable sections. Displacement and stress constraints together with the geometry constraints are imposed on the frame in the optimum design procedure. In addition, non-linear analyses considering the P-${\Delta}$ effects of beam-column members are performed during the optimization process. Three design examples with various types of connections are presented and the results show the efficiency of using semi-rigid connection models in comparing to rigid connections. The obtained optimum semi-rigid frames are more economical solutions and lead to more realistic predictions of response and strength of the structure.

• Journal of Korea Multimedia Society
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• v.9 no.1
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• pp.119-126
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• 2006

The task scheduling in multiprocessor system is one of the key elements in the effective utilization of multiprocessor systems. The optimal assignment of tasks to multiprocessor is, in almost practical cases, an NP-hard problem. Consequently algorithms based on various modern heuristics have been proposed for practical reason. This paper proposes a new task scheduling algorithm using Genetic Algorithm which combines simulated annealing (GA+SA) in multiprocessor environment. In solution algorithms, the Genetic Algorithm (GA) and the simulated annealing (SA) are cooperatively used. In this method, the convergence of GA is improved by introducing the probability of SA as the criterion for acceptance of new trial solution. The objective of proposed scheduling algorithm is to minimize makespan. The effectiveness of the proposed algorithm is shown through simulation studies. In simulation studies, the result of proposed algorithm is better than that of any other algorithms.

• The Journal of Industrial Distribution & Business
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• v.13 no.12
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• pp.59-71
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• 2022

Purpose: Re-handling is an important factor that reduces the productivity of container terminals. The purpose of this paper is to propose an algorithm to find the order of container movement in order to minimize the number of re-handling in the process of carrying-out. Research design, data and methodology: This paper proposes an algorithm to set the optimal carry-out order and conducted tests to evaluate the performance of the algorithm proposed in this paper. 1. tests comparing the performance of an algorithm proposed in an existing study with that proposed in this paper. 2. Performance tests for bays with complex structures. Results: Test 1 shows that the algorithm proposed in this paper performs better than the existing algorithm. Test 2 shows that the proposed algorithm can also be used in bays with considerably high complexity and that there is no major problem with using it in the field. Conclusion: While we can conclude that the proposed algorithm as a carry-out algorithm is more effective than conventional methods, research is needed on how to handle more complex bays more effectively. This is because the larger the bay, the more container combinations increase, making it difficult to find the best carry-out order.

• International conference on construction engineering and project management
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• 2024.07a
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• pp.823-830
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• 2024

Effective project planning is essential in construction project management for timely delivery and economic benefit realization. Work packages are pivotal in this planning, providing clear organization and progress tracking. However, existing methods for creating work package schemes often overlook environmental sustainability, specifically carbon emissions-a growing concern in construction. This study introduces a tabu search-based optimization method for work package schemes, aiming to reduce both project costs and carbon emissions. A cost-carbon model is devised, and a tabu search algorithm is developed to identify the Pareto frontier for total project cost and carbon emissions. A case study shows the tabu search outperforms existing heuristics, reducing carbon emissions by 6.19% with a marginal cost increase of 0.9%. The algorithm's adaptability and generalizability suggest it could significantly enhance economic and sustainable outcomes in construction project planning.

• Journal of Korea Game Society
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• v.13 no.6
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• pp.43-52
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• 2013

Path finder is one of the very important algorithm of artificial intelligence and is a process generally used in many game fields. Path finder requires many calculation, so it exerts enormous influences on performances. To solve this, many researches on the ways to reduce the amount of calculate operations have been made, and the typical example is A* algorithm but it has unnecessary computing process, reducing efficiency. In this paper, to reduce the amount of calculate operations such as node search with costly arithmetic operations, we proposes the weight based pre-processing A* algorithm. The simulation was materialized to measure the efficiency of the weight based pre-process A* algorithm, and the results of the experiments showed that the weight based method was approximately 1~2 times more efficient than the general methods.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.12
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• pp.3236-3245
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• 1994

The nesting of two-dimensional patterns onto a given raw sheet has applications in a number industries. It is a common problem often faced by designers in the shipbuilding, garment making, blanking die design, glass and wood industries. This paper presents a multi-stage layout approach for nesting two-dimensional patterns by using artificial intelligence techniques with a relatively short computation time. The raw material with irregular boundaries and internal defects which must be considered in various cases of nesting was also investigated in this study. The proposed nesting approach consists of two stages : initial layout stage and layout improvement stage. The initial layout configuration is achieved by the self-organizing assisted layout(SOAL) algorithm while in the layout improvement stage, the simulated annealing(SA) is adopted for a finer optimization.

• Journal of the Korean Society for Railway
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• v.8 no.5
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• pp.411-418
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• 2005

This paper expounds the development of a user-friendly expert system for the optimal stacking sequence design of composite laminates subjected to the various rules constraints. The expert system was realized in the graphic-based design environment. Therefore, users can access and use the system easily. The optimal stacking sequence is obtained by means of integration of a genetic algorithm, finite element analysis. These systems were integrated with the rules of design heuristics under an expert system shell. The optimal stacking sequence combination for the application of interest is drawn from the discrete ply angles and design rules stored in the knowledge base of the expert system. For the integration and management of softwares, a graphic-based design environment that provides multi-tasking and graphic user interface capability is built.

• The KIPS Transactions:PartB
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• v.16B no.5
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• pp.411-426
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• 2009

Most of the metaheuristics are made by imitating the action of the animals. In this paper, we proposed Mine Algorithm. The Mine Algorithm is a metaheuristic that imitates the action of the human being. Speaking of search, the field in which the know-how and the heuristics of the human being are melted best is the mining industry. In the Mine Algorithm we formalize the action pattern of the human being by focusing the mine business. The Mine Algorithm uses various searching techniques fluently and shows equally good performance for broad problems. That is, it has good generality. We show the improved generality of the Mine Algorithm by the comparing experiments with the conventional metaheuristics.