• The KIPS Transactions:PartD
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• v.11D no.2
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• pp.269-280
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• 2004

The Pyramid-Technique is based on mapping n-dimensional space data into one-dimensional data and expresses it as a B+-tree. By solving the problem of search time complexity the pyramid technique also prevents the effect of "phenomenon of dimensional curse" which is caused by treatment of hypercube range query in n-dimensional data space. The SPY-TEC applies the space division strategy in pyramid method and uses spherical range query suitable for similarity search so that Improves the search performance. However, nearest neighbor query is more efficient than range query because it is difficult to specify range in similarity search. Previously proposed index methods perform well only in the specific distribution of data. In this paper, we propose an efficient searching technique for nearest neighbor object using PdR-Tree suggested to improve the search performance for high dimensional data such as multimedia data. Test results, which uses simulation data with various distribution as well as real data, demonstrate that PdR-Tree surpasses both the Pyramid-Technique and SPY-TEC in views of search performance.rformance.

• The KIPS Transactions:PartD
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• v.10D no.5
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• pp.813-820
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• 2003

This paper solves Push-Push game with the model checker NuSMY which exhaustively explores all search space to determine whether a model satisfies a property. In case a model doesn't satisfy properties to be checked, NuSMV generates a counterexample which tells where this unsatisfaction occurs. However, the algorithm for generating counterexample in NuSMV traverses a search space twice so that it is inefficient for solving the game we consider here. To save the time to be required to complete the game, we revise the part of counterexample generation so that it traverses a search space once. As a result, we obtain 62% time improvement and 11% space improvement in solving the game with modified NuSMV.

• Publications of The Korean Astronomical Society
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• v.21 no.1
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• pp.1-9
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• 2006

An archiving system designed to enable documenting database of astronomical images, with functions of search and download, is being developed by Korean Astronomical Data Center(KADC) of Korea Astronomy and Space Science Institute(KASI). The system consists of three PCs for web server, database server, and system management server. The search program for the web environment is operated in the web server. In the management server, several utility program we developed are installed: input program for the database, program for transfer from fits to jpg files, program for data recovery and management, and programs for statistics and connect management. The collected data would be sorted out by the system manager to input into the database. The online input is possible in an observatory where the data is produced. We applied the content management system(CMS) module for the database management. On the basic of CMS module, we set up a management system for the whole life cycle of metadata from creation and collection to storage and deletion of the data. For the search function, we employed a technique to extract indices from the metadata. In addition, MySQL is adopted for DBMS. We currently display about 2,700 and 25,000 photographs for astronomical phenomena and astronomical objects on the data, respectively.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2008.10a
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• pp.353-358
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• 2008

The ocean has settled down in human mind as a territory and a leisure space from which anyone enjoys and takes a benefit under the national sovereignty, as the new era of Sea comes. In addition, because the population engaged in marine activities has rapidly increased, the number of marine accidents consequently has grown up as well. In this reason, currently it has been highlighted to devise safety measures to prevent large scale accidents or disasters on the oceans. Therefore, this thesis firstly points out issues and problems of current search and rescue operations, and secondly studies three primary factors of the search and rescue operations, which are decision of search range, decision of search asset, and decision of search duration. Finally, the thesis suggests a theoretical foundation of the search and rescue operations by applying the result of studies and the marine search theory through a theoretical approach to reasonable standards.

• Proceedings of the IEEK Conference
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• 2002.07a
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• pp.462-465
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• 2002

This paper presents a basic theory of information flow from single sending point to multiple receiving points, where new theories of algebraic system called "Hybrid Vector Space" and flow vector space play important roles. Based on the theory, a new algorithm for finding maximum homogenous information flow is proposed, where homogenous information flow means the flow of the same contents of information delivered to multiple clients at a time. Effective multi-routing algorithms fur tree-shape delivery rout search are presented.

• Journal of Astronomy and Space Sciences
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• v.29 no.1
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• pp.41-45
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• 2012

This paper reports the progress of a search for exoplanets with S-type orbits in short-period binary star systems. The selected targets have stellar orbital periods of just a few days. These systems are eclipsing binaries so that exoplanet transits, if planets exist, will be highly likely. We report the results for seven binary star systems.

• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.558-562
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• 1999

In this paper, the inverter spot welding system with high efficiency via an instantaneous power control is presented. In spot welding, instantaneous power control is utilized in order to attain less spatter and high welding performance. Also we proposed a PI controller for spot welder system using Evolution Strategy(ES) with varying search space. ES with varying search space which depends on fitness values at each generation is used to tune PI control parameters

• Journal of Korean Institute of Industrial Engineers
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• v.25 no.2
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• pp.226-232
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• 1999

Graph Coloring Problem(GCP) is a problem of assigning different colors to nodes which are connected by an edge. An extended form of GCP is TCP (T-coloring problem) and, in TCP, edge weights are added to GCP and it is possible to extend GCP's applications. To solve TCP, in this paper, we propose an improved Simulated Annealing(SA) method with search space smoothing. It has been observed that the improved SA method obtains better results than SA does.

• Proceedings of the Korea Information Processing Society Conference
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• 2011.04a
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• pp.990-992
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• 2011

In this paper, we introduce a new Tabu method to get K-anonymity character in database information privacy protection. We use the conception of lattice to form the solution space for K-anonymity Character and search the solution area in this solution space to achieve the best or best approach modification solution for the information in the database. We then compared the Tabu method with other traditional heuristic method and our method show a better solution in most of the cases.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.8
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• pp.737-743
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• 2009

Design optimization process and results of Loop Heat Pipe(LHP) using Tabu Search have been presented in this study. An objective of optimization is to reduce a mass of the LHP with satisfying operating temperature of a Lithium Ion battery onboard an aircraft. The battery is assumed to be used as power supply of air borne high energy laser system because of its high specific energy. The analytical models are based on a steady state mathematical model and the design optimization is performed using a Meta Model and Tabu Search. As an optimization results, the Tabu search algorithm guarantees global optimum with small computation time. Due to searching by random numbers, initial value is dominant factor to search global optimum. The optimization process could reduce the mass of the LHP which express the same performance as an published LHP.