• Proceedings of the KIEE Conference
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• 1999.07c
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• pp.1098-1100
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• 1999

This paper proposes a method of solving a unit commitment problem using tabu search (TS). The TS is efficient optimization method using meta-heuristic. To improve the diversification properties of TS, path relinking method is introduced. To show the usefulness of the proposed method, we performed an experiment for the system of 10 units. Numerical results show improvements in the generation cost and the computation time compared to previously obtained results.

• Proceedings of the Korean Society for Bioinformatics Conference
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• 2003.10a
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• pp.245-250
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• 2003

There are currently about 6000 bacterial species with validly published names, but scientists assume that these may be less than 1% of bacterial species present on the earth. Microbial resource is one of the most important bioresources in bioinderstry and provides us with high economic values. To find missing ones, the studies of metagenome, metabolome, and proteome about microbes have started recently in developed countries. We construct the information system that integrates information on microbial genome resources and manages the information to support efficient research of microbial genome application, and name this system 'Bio-Meta Information System (Bio-MIS)'. Bio-MIS consists of integrated microbial genome resources database, microbial genome resources input system, integrated microbial genome resources search engine, microbial resources on-line distribution system, portal service and management via internet. In the future, we will include public database connection and implement useful bioinformatics software for analyzing microbial genome resources. The web-site is accessible at http://biomis.probionic.com

• Proceedings of the KIEE Conference
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• 2001.05a
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• pp.84-88
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• 2001

This paper proposes a method of solving a unit commitment problem using parallel tabu search (PTS). The TS is efficient optimization method using meta-heuristic. In this paper, to reduce the computation time for evaluating the neighborhoods, an evaluating method only on changed part and a path relinking method as diversification strategy are proposed. To show the usefulness of the proposed method, we simulated for 10 units system and 110 units system. Numerical results show improvements in the generation costs and the computation time compared with conventional methods. Numerical results show improvements in the generation cost and the computation time compared to previously obtained results.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.6
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• pp.1354-1359
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• 2013

With the development of multimedia and network technology, the production of multimedia contents is rapidly increasing. Meanwhile, the technology to search and use the contents is still insufficient. There are standards for multimedia contents to address the problem, but they cannot fully support diverse multimedia data types or ensure their interoperability. In this paper, an ontology-based content search system is proposed to ensure the interoperability of multimedia contents. The ontology is configured by presenting the rules for it using the schema structure of the multimedia description scheme (MDS) of MPEG-7. Based on this ontology, This paper extend multimedia relationship based on ontology, thus established the semantic retrieval system.

• Journal of KIISE:Software and Applications
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• v.29 no.9
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• pp.645-653
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• 2002

The unit commitment problem in a power system involves determining the start-up and shut-down schedules of many dynamos for a day or a week while satisfying the power demands and diverse constraints of the individual units in the system. It is very difficult to derive an economically optimal schedule due to its huge search space when the number of dynamos involved is large. Tabu search is a popular solution method used for various optimization problems because it is equipped with effective means of searching beyond local optima and also it can naturally incorporate and exploit domain knowledge specific to the target problem. When given a large-scaled problem with a number of complicated constraints, however, tabu search cannot easily find a good solution within a reasonable time. This paper shows that a large- scaled optimization problem such as the unit commitment problem can be solved efficiently by using a parallel tabu search. The parallel tabu search not only reduces the search time significantly but also finds a solution of better quality.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.27 no.2
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• pp.171-191
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• 2016

This research was examined to evaluate whether the websites of 6 policy research institutes provide web resources which were collected and provided as information resources, and that they were sure that the web resources had value as policy information by content analysis method. Web resources provided as policy information in policy research institutes were classified into and evaluated by 4 categories. Evaluation had been conducted on 10 items in the 4 categories of content, design, accessibility and meta data. From the result, the information content have been found to be reliable and up-to-date although more thorough description is required. Navigation and the search function in the design category were found to be excellent, but dead links were present in all of the institutions. The accessibility was proven to be great as it was able to access information with only three clicks. However, it has been found that a comprehensive review of the meta data is required in order to improve the accuracy of search functions. In conclusion, improvements to the dead link problems, quality control of the meta data, systematic and professional management plan of policy research information, and the establishment of a comprehensive policy research information portal system have been proposed.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.44 no.2
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• pp.58-65
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• 2021

Meta-heuristic algorithms have been developed to efficiently solve difficult problems and obtain a global optimal solution. A common feature mimics phenomenon occurring in nature and reliably improves the solution through repetition. And at the same time, the probability is used to deviate from the regional optimal solution and approach the global optimal solution. This study compares the algorithm created based on the above common points with existed SA and HS to show advantages in time and accuracy of results. Existing algorithms have problems of low accuracy, high memory, long runtime, and ignorance. In a two-variable polynomial, the existing algorithms show that the memory increases and the accuracy decrease. In order to improve the accuracy, the new algorithm increases the number of initial inputs and increases the efficiency of the search by introducing a direction using vectors. And, in order to solve the optimization problem, the results of the last experiment were learned to show the learning effect in the next experiment. The new algorithm found a solution in a short time under the experimental conditions of long iteration counts using a two-variable polynomial and showed high accuracy. And, it shows that the learning effect is effective in repeated experiments.

• Journal of applied mathematics & informatics
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• v.29 no.5_6
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• pp.1571-1581
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• 2011

In this paper, we construct inequivalent Hadamard matrices based on several new and old full orthogonal designs, using circulant and symmetric block matrices. Not all orthogonal designs produce inequivalent Hadamard matrices, because the corresponding systems of equations do not possess solutions. The systems of equations arising when we search for inequivalent Hadamard matrices from full orthogonal designs using circulant and symmetric block matrices, can be concisely described using the periodic autocorrelation function of the generators of the block matrices. We use Maple, Magma, C and Unix tools to find many new inequivalent Hadamard matrices.

• Journal of Electrical Engineering and Technology
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• v.12 no.4
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• pp.1417-1426
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• 2017

Power system analysis, Non-Convex Economic Dispatch (NED) is considered as an open and demanding optimization problem. Despite the fact that realistic ED problems have non-convex cost functions with equality and inequality constraints, conventional search methods have not been able to effectively find the global answers. Considering the great potential of meta-heuristic optimization techniques, many researchers have started applying these techniques in order to solve NED problems. In this paper, a new and efficient approach is proposed based on imperialist competitive algorithm (ICA). The proposed algorithm which is named multi-operator ICA (MuICA) merges three operators with the original ICA in order to simultaneously avoid the premature convergence and achieve the global optimum answer. In this study, the proposed algorithm has been applied to different test systems and the results have been compared with other optimization methods, tending to study the performance of the MuICA. Simulation results are the confirmation of superior performance of MuICA in solving NED problems.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2000.04a
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• pp.9-12
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• 2000

컨테이너 터미널에서 효율적인 적하작업 계획을 자동으로 생성하는 알고리즘을 연구하였다. 실제 터미널에서 계획자들이 적하작업 계획시에 고려하는 제약소건 및 효율적인 계획을 위한 고려사항을 조사하였다. 이를 바탕으로 1단계에서는 개미시스템(ant system)이라는 인공지능기법을 적용하여 제약조건을 만족시키면서 원활한 적하작업이 진행될 수 있도록 컨테이너 크레인과 트랜스퍼 크레인의 이동순서와 위치를 결정하고, 2단계에서는 1단계에서의 결과를 바탕으로 빔탐색법(beam search)을 사용하여 컨테이너 개개의 작업순서를 결정하는 알고리즘을 개발하였다. 또한 개발된 시스템의 성능을 검증하기 위하여 최근의 대형선반에 대한 실제 현장자료를 바탕으로 실험을 수행하였다.