• Journal of Applied Reliability
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• v.9 no.3
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• pp.219-231
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• 2009

Power light emitting diodes(LED) for lighting fittings are so much environment-friendly, highly reliable and consume less energy that they are widely used at home and in industries such as electronics, telecommunications and industrial machineries. However, they are exposed to a very diverse environment and consists of complex components and, therefore needs careful approach to the enhancement and assessment of reliability of the item. In this article reliability assessment criteria for LED are established in terms of performance assessment test, reliability assessment test and accelerated test.

• Journal of the Korean Society of Clothing and Textiles
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• v.38 no.6
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• pp.810-822
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• 2014

This study investigated the effects of sociocultural influence and body image on appearance enhancement behavior (facial management, clothing selection, and weight/figure management). For data collection, a questionnaire was administrated to 378 female college students in Seoul and Gyeonggi-do from May $23^{rd}$ to June $10^{th}$ 2013. A SPSS 18.0 statistics package was used to analyze data along with descriptive statistical analysis, frequency analysis, factor analysis, reliability analysis, and regression analysis and frequency analysis. The results were as follows. First, sociocultural influences were divided into three factors: media influence, peer influence, and parental influence. Overall sociocultural influences had positive effects on appearance enhancement behavior. Second, body image was divided into: appearances-management, body-satisfaction and body confidence. Sociocultural influences had a significant effect on overall body image. Third, body image positively affected overall appearance enhancement behavior.

• Journal of Applied Reliability
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• v.9 no.2
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• pp.93-106
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• 2009

GPS(Global positioning system) system is widely used in artificial satellite, ground controlled approach system as well as in end-user environment such as in the automobile. It is exposed to a very diverse environment and consists of many complicated components and therefore needs careful approach to the enhancement of reliability of the item. In this article reliability standards for the GPS system are established in terms of quality certification tests and failure rate tests.

• Journal of Applied Reliability
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• v.9 no.3
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• pp.259-274
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• 2009

Printed circuit boards for RAM are widely used in modern electronics such as computers, artificial satellites and consumer durables. They are exposed to a very diverse environment and consists of many complicated components and therefore needs careful approach to the enhancement and assessment of reliability of the item. In this article reliability standards for PCBs for RAM are established in terms of quality certification tests and failure rate tests.

• Journal of Applied Reliability
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• v.9 no.3
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• pp.195-218
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• 2009

Wiper motors are used in every automobile. They are exposed to a very diverse environment and consists of several components and, therefore needs careful approach to the enhancement and assessment of reliability of the item. In this article reliability standards for wiper motors are established in terms of quality certification test and failure rate test.

• Journal of Korean Society for Quality Management
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• v.25 no.3
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• pp.96-107
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• 1997

The recent stream to reliability prediction is that it is totally inclusive in depth to consider even the operating and environmental condition at the level of finished goods as well as component itselves. In this study, firstly we present the reliability prediction methods by entire failure rate model which failure rate at the system level is added to the failure rate model at the component level. Secondly we build up the improved bases of reliability demonstration through a, pp.ication of Kaplan-Meier, Cumulative hazard, Johnson's methods as non-parametric and Maximum Likelihood Estimator under exponential & Weibull distribution as parametric. And also present the methods of curve fitting to piecewise failure rate under Weibull distribution, PRST (Probability Ratio Sequential Test), curve fitting to S-shaped reliability growth curve, computer programs of each methods. Lastly we show the practical for determination of optimal burn-in time as a method of reliability enhancement, and also verify the practical usefulness of the above study through the a, pp.ication of failure and test data during 1 year.

• Proceedings of the KIEE Conference
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• 2006.07a
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• pp.58-59
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• 2006

신뢰도 향상기법(System-based Reliability Enhancement Technology : SRET)이란 시스템레벨에서 IED의 신뢰도를 개선하는 방법이다. 변전소 자동화 시스템(SAS)에서 각 IED들은 각자의 역할에 충실하여 정상적으로 동작하여야 한다. 어떠한 IED에 이상이 생겼을 경우, 변전소 내 시스템에서는 그 IED의 이상 여부를 감지하고 그에 적절한 조치가 취해져야 한다. 본 논문은 IEC61850 기반 SCL(Substation Configuration description Language)를 이용한 SAS에서 같은 역할을 하는 백업 IED를 구성하여 임의의 사고에도 시스템 동작에 아무런 영향을 미치지 않는 시스템 신뢰도 향상 기법의 구현을 설명하였다. 제안한 기법의 효율을 검증하기 위하여 실제 시뮬레이터를 사용하여 시뮬레이션을 수행하고 그 결과를 수록하였다.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.3
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• pp.536-542
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• 2010

This paper presents an unique approach to scheme a demand response (DR) program in the electricity market from a customer-oriented perspective, which is based on the analytic hierarchy process (AHP). The proposed program has the objective to maintain the system reliability at the emergency period, and it is designed as an incentive-based program (IBP) considering Korea power systems with the cost-based generation pool (CBP). The DR program using AHP could represent the mutual importance degrees of load curtailment criteria from the viewpoint of different load-holders, thus customers' participation in this program is determined by the incentive payments corresponding the specific load curtailment conditions. A test system for the case study is used to demonstrate the usefulness and applicability of the proposed approach, and the load profiles with the proposed DR program and the required incentive payments are obtained. The results show not only the enhancement of system reliability but also the economic benefit within Pareto-improvement.

• Proceedings of the KIEE Conference
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• 1986.07a
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• pp.114-118
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• 1986

• Journal of the Korean Institute of Telematics and Electronics
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• v.27 no.6
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• pp.895-900
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• 1990

With the MOS device scailing down, the substrate concentration must increase in order to avoid punchthrough leakage current due to the DIBL(Drain Induced Barrier Lowering) effect. However the enhancement of the substrate concentration increases source, drain juntion capacitances and substrate current due to hot elelctron, degrading the speed characteristics and reliability of the MOS devices. In this paper, a new device, called CODE(Channel Only Dopant Enhancement) MOS, an its fabrication are proposed. By comparing the fabricated CODE MOSFET with the conventional device, the improvements on DIBL, substrate current and source, drain juntion capacitances are realized.