• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.9
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• pp.1491-1499
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• 2008

This paper presents a study on reliability evaluation of a power system considering wind turbine generators (WTG) with multi-state. Renewable energy resources such as wind, wave, solar, micro hydro, tidal and biomass etc. are becoming importance stage by stage because of considering effect of the environment. Wind energy is one of the most successful sources of renewable energy for the production of electrical energy. But, reliability evaluation of generating system with wind energy resources is a complex process. While the wind turbine generators can not modelled as two-state model as like as conventional generators, they should be modelled as multi-state model due to wind speed random variation. The methodology for obtaining reliability evaluation index of wind turbine generators is different from it of the conventional generators. A method for making outage capacity probability table of WTG for reliability is proposed in this paper. The detail process is presented using case study of simple system.

• Journal of the Korean Society of Industry Convergence
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• v.22 no.5
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• pp.537-544
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• 2019

In currently electronic systems, the speed of information integration has increased due to the development of electronic technology. However, due to the increase in the number of parts and groups, the product structure has become complicated. In this paper, a study was conducted to evaluate quantitatively the replacement of a small equipment. First, the level of the replacement was determined through the algorithm for the replacement level of parts. Next, we defined the ease of detail replacment, and the factors for each detail replacement. In order to calculate the weighting of the detail ease, we performed the analysis of the replacement process of subcomponents of communication exchanger and defined the evaluation criteria. Finally, the completion of the evaluation check sheet and the evaluation score table.

• Journal of the Korea institute for structural maintenance and inspection
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• v.12 no.4
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• pp.107-114
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• 2008

Currently, each managing agencies are enforcing the maintenance against the cutting slopes, but the universality and objectivity are insufficient, because the evaluation item and model are various, the access method is not mutual-supplementary. Consequently, this study will lead the approach for a rational model development, by the analysis against the existing cutting slope evaluation technique, excavate a collapse primary reason and a factor, by the collapse example analysis, and make out evaluation table to decide a investigation priority of the existing cutting slope in the Investigation Evaluation step using AHP.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2002.03a
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• pp.93-100
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• 2002

In this paper, new simple model is developed to evaluate the variation of the magnitude and the phase contrast of force components with the development of excess pore pressure in backfill soil. Also, Newmark sliding block analysis is performed inputting the calculated total force from new model. The applicability of new simple model and Newmark sliding block model is verified from the analyses of 1g shaking table test results.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.35 no.10
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• pp.458-464
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• 1986

This paper introduces a method for design verification and performance evaluation of flight control system. The method is a real time hardware in the loop simulation using the hybrid computer and motion table facility. As a typical illustration, a roll control system of flight vehicle is applied. The simulation validity is demonstrated by comparing hardware test results with analog simulation results.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.455-456
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• 2009

Although pseudo-dynamic test and shaking table test have been performed using small scale models to evaluate the seismic performance of RC structures, researches on similitude law are not sufficient. This study presents a reasonable similitude law for improvement of economical efficiency and reliability.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1460-1460
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• 2015

Power equipment, since different life according to use environment, there is a need for systematic maintenance management Efforts to reduce the economic losses due to accidents by making self evaluation table will be necessary.

• Proceedings of the Korean Geotechical Society Conference
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• 1993.06a
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• pp.1-14
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• 1993

Ground reinforcements is the essential method to prevent the liquefaction of loose sand deposit, However, in the construction of the life lines, it is impossible to treat the whole loose deposit against liquefaction. As an countmeasure for the life lines against the liquefaction, a monitorning system can be considered for an immediate judgement of the liquefaction occurrence during an earthquake. Through shaking table tests on model grounds, pore presure developments were investigated in terms of the surface spectral velocity, which was verified as a tool for the immediate judgement of the liquefaction occurrence.

• Proceedings of the Korean System Dynamics Society
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• 2004.02a
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• pp.109-128
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• 2004

A system dynamics model is developed in order to evaluate the contribution level of the activities regarding HANARO, which is the research reactor in Korea. The system dynamics model has room to be improved, but it is logically sound enough to evaluate the general level of contributions and to develop strategies for the HANARO to be more contributable. Considering the uncertainty involved with the input variables, the contribution level is ranged from 3 times to about 30 times of the investment made on it. The evaluation results can be summarized as follows : (Table Omitted).

• Proceedings of the Korean Information Science Society Conference
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• 2003.04a
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• pp.731-733
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• 2003

기존의 데이타베이스 시스템에서 주요 성능문제는 대부분 응용프로그램의 SQL문에서 발생한다. 특히 다중 테이블을 이용한 SQL문에서 필수적으로 사용하는 JOIN 연산이 단순 질의 연산에 비해 많은 성능 문제점을 갖고 있다. 따라서 본 연구에서는 관계형 데이타베이스시스템에서 JOIN연산의 효율성을 높이기 위한 방안을 설정하고 이를 적용해 본다.