• Proceedings of the KSR Conference
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• 2007.05a
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• pp.836-845
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• 2007

In DC 1500V electric traction substations, diode rectifiers are commonly used to supply stable DC power with electric train sets. However, it operates in the first quadrant of the voltage-current plane and thus needs regenerative inverters which transfer the surplus regenerative power caused by regenerative braking of electric train sets into the grid. In order to select the proper capacity and installation position of regenerative inverter, it needs to investigate the consumed and regenerative energy of the electric traction substations in advance. This paper presents an analysis of regenerative energy in two substations operating in Seoul line 2 and Kwangju line 1. DC line voltage and feeder currents are measured for a day to calculate consumed and regenerative power for four feeders. We calculated an amount of regenerative energy consumed in other feeders and estimated the cost reduction in energy consumption due to the reuse of regenerative energy.

• Journal of the Korean Operations Research and Management Science Society
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• v.37 no.4
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• pp.19-35
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• 2012

The Semantic Web technology, purporting to share, to reuse and to process by machines data stored in the Web environment, incessantly evolves to help human decision making; in particular, decision making based on data, or quantitative decision making. This trend drives researchers to fill the gap with strenuous efforts between the current state of the technology and the terminus of this evolution. The Semantic Web Constraint Language (SWCL) together with SWRL is one of these endeavors to achieve the goal. This paper focuses particularly on how to express the piecewise linear form in the context of SWCL. The importance of this ingredient can be fortified by the fact that any nonlinear expression can be approximated in the piecewise linear form. This paper will also provide the information of how it will work in the decision making process through an example of the Internet shopping mall problem.

• Journal of Korea Multimedia Society
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• v.9 no.6
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• pp.750-761
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• 2006

As CBD technologies and researches have been matured, component framework as a larger reuse unit than component is being introduced. Especially issues related with adaptation and integration of components in CBD are being raised as a new research topic. The component framework is given as a solution to resolve these issues. However, current approaches don't suggest a sound and comprehensive reference model and development process applying reference model. In order to develop practical and stable component framework, reference model and concrete guidelines are essential elements. In this paper, we propose a generic reference model integrating existing reference models and a design technique of component framework based on it. Especially, we propose concrete and pragmatic guidelines such as how to design component framework architecture's view and style, how to design commonality and variability of component framework, how to design macro workflows among components, and so on. We believe that the proposed reference model becomes basis for component framework development, and the proposed design technique will support reliable and effective development of the component framework.

• Journal of Engineering Education Research
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• v.4 no.2
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• pp.27-34
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• 2001

Java Applets are major learning components in current Web-based educational system. In this paper, it is shown how Java Beans technology is applied to develop engineering Java Applets. This technique enables us to reuse the developed components and to increase the programming productivity. Also, these components are integrated into 5 different Applet types, each of which represents a good educational pattern in Applet programming. The results are applied to develop engineering class contents like Electrical Circuit theory, Engineering Mathematics, athematics, and Electrical Machine. Development times are analysed to show how this technique helped in reducing production period.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2002.05a
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• pp.163-170
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• 2002

The High Level Architecture(HLA) for modeling and simulation was developed as means of facilitating interoperability among simulations and promoting reuse of simulations and their components. The purpose of this paper is to provide a summary of the latest release of the HLA concept, supporting utilities and develop the prototyped Transportation Movement Management(TMM) federation. To obtain this goal, the Federation Development and Execution Process(FEDEP) is being applied to development of TMM federation will consist of three federates. This paper outlines the rationale of our approach, describes the application of the FEDEP in the development of the federation, and provides the current status of the federation development. The resulting federation shows complete interoperability among simulation components in the TMM federation and satisfactory simulation outputs. We present a description and process of the federation and the lessons learned with the process utilization for federation development and execution. Furthermore, the issues in establishing a HLA based federation across multiple legacy simulations are discussed.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.551-556
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• 2004

The deterioration of a shunting locomotive was characterized for the lifetime assessment. The locomotive has been used for shunting works in steel making processes, and in this investigation, various types of technical evaluation methods for the locomotive parts were employed to assess the current deterioration status and to provide important clue for lifetime prediction. Unlike other rolling stocks in railway applications, the diesel shunting locomotive is composed of major components such as diesel engine, transmission, gear box, brake system, electronic devices, etc., which cover more than 70 percent of the total price of the locomotive. Therefore, in this paper, each part of major components in the diesel locomotive was analyzed in terms of the degree of deterioration. The life-cycle-cost (LCC) analysis was performed based on the maintenance and repair history as compared with economical cost to provide the cost-effective prediction, i.e., to assess either repair for reuse or putting the locomotive out of service based on cost-effective calculation.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.247-258
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• 2008

Environmental standards for beneficial uses of dredged materials are proposed. Even though chemical analysis of ocean sediments are carried out frequently, their analyses results were not interrelated with the effects of biological lives due to a shortage of biological data. These facts have resulted in difficulty to develope Korean's standards of recycling dredged materials. This paper first searched existing current foreign standards, analyzed local contaminated ocean sediment data, identified their main chemical components of contaminants, and then compared with clean-up standards of sediments consisting of lower and higher levels. From these analysis, new environmental standards considering Korean domestic circumstances are proposed. It is judged that new standards are appropriate to both Korean national sedimental environments and economically recycling aspects because environmental standard levels proposed are higher than background levels of sediments in Korean and foreign standards.

• Journal of the Korea Society for Simulation
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• v.11 no.2
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• pp.31-43
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• 2002

The High Level Architecture(HLA) for modeling and simulation was developed as means of facilitating interoperability among simulations and promoting reuse of simulations and their components. The purpose of this paper is to provide a summary of the latest release of the HLA concept, supporting utilities and develop the prototyped Transportation Movement Management(TMM) federation. To obtain this goal, the Federation Development and Execution Process(FEDEP) is being applied to development of TMM federation will consist of three federates. This paper outlines the rationale of our approach, describes the application of the FEDEP in the development of the federation, and provides the current status of the federation development. The resulting federation shows complete interoperability among simulation components in the TMM federation and satisfactory simulation outputs. We present a description and process of the federation and the lessons learned with the process utilization for federation development and execution. Furthermore, the issues in establishing a HLA based federation across multiple legacy simulations are discussed.

• Journal of the Korean housing association
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• v.15 no.3
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• pp.109-116
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• 2004

The purpose of this study is to improve the residential environment of the deteriorated apartment in Gyeongju. We survey the characteristics of each of the seven buildings in the subject housing, the renovations of each unit and the overall environment, and the residents' perceptions. The findings show that the residents of the deteriorated apartment in Gyeongju are generally satisfied with the current residential environment and that they prefer the reconstruction to improve their environment. The results also include that the residents feel burdened with the reconstruction because it is difficult to receive the approval from the local government and it is highly costly from the view points of the residents. It is recommendable to establish the logical judging criteria on the reconstruction. reuse, or renovation of the deteriorated apartment in a small local city such as Gyeongju and to offer the objective and specific programs on the basis of the established criteria for the improvement of the residential environment in the future.

• Journal of Information Technology Services
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• v.9 no.2
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• pp.193-203
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• 2010

Service-Oriented Architecture (SOA) is a new trend for the design of application architecture to enhance the degree of share and reuse with the concept of service. It comes from the current situation where the business environments are changing rapidly and therefore competitions are getting bitter. To cope with such business challenges, business (and/or applications) architecture needs considerably flexibility and reusability, and that's why SOA is accepted as one of the most effective framework for the business applications in these days. In this paper we propose an analysis and design methodology for the applications of SOA. To implement the proposed methodology, the service ontology needs to be defined first, and the tasks such as service profiling, workflow design and service orchestration need to be followed. To validate the expected effects on flexibility and reusability, the proposed methodology was compared with CBD (Component Based Development).