• Industrial Engineering and Management Systems
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• v.9 no.1
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• pp.54-59
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• 2010

A two-plan sampling system is proposed for a failure-censored life testing when the lifetime follows a Weibull distribution with known shape parameter. The proposed sampling system is based on a switching rule, for switching between the tightened and the normal inspection levels when lots are submitted for inspection in the order of production or in some other systematic way. The design parameters of the proposed sampling system are determined by the two-point approach considering the producer's risks and the consumer's at the specified acceptable reliability level and the lot tolerance reliability level, respectively. It has been observed that the proposed system requires only a single failure for the observation.

• Journal of the Korean Solar Energy Society
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• v.30 no.6
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• pp.95-101
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• 2010

This paper presents performance estimation approach of grid-connected photovoltaic(PV) system to predict energy yield from irradiance to PV system using normalized yield model for changing meteorological conditions. The accuracy and validity of proposed performance estimation method is identified by compared measured with estimated yield using monitored data. These results will indicate that it is useful to estimate various loss factors causing the system performance obstruction and enhance the lifetime yield of PV system.

• Proceedings of the KIEE Conference
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• 2004.05a
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• pp.150-152
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• 2004

The battery charge/discharge process, the final step of the secondary battery production process, requires real-time precision controls for improving both lifetime and performance of the battery cell. In this paper, we present embedded system design for precision control of the secondary battery charge/discharge production process using low power embedded processor based on embedded linux. This system receive charge/discharge command from the main server through ethernet. Compared to existing charge/discharge control system, our design makes low cost and precision control system possible.

• Electrical & Electronic Materials
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• v.11 no.11
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• pp.1-8
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• 1998

This paper presents an arificial neuro-fuzzy technique based prtial discharge (PD) pattern classifier to power system application. This may require a complicated analysis method employ -ing an experts system due to very complex progressing discharge form under exter-nal stress. After referring briefly to the developments of artificical neural network based PD measurements, the paper outlines how the introduction of new emerging technology has resulted in the design of a number of PD diagnostic systems for practical applicaton of residual lifetime prediction. The appropriate PD data base structure and selection of learning data size of PD pattern based on fractal dimentsional and 3-D PD-normalization, extraction of relevant characteristic fea-ture of PD recognition are discussed. Some practical aspects encountered with unknown stress in the neuro-fuzzy techniques based real time PD recognition are also addressed.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2002.11a
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• pp.201-204
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• 2002

Electrodeless fluorescent lamps utilizing an inductively coupled plasma were found to have a long lifetime and high efficacy and now are used in some indoor and outdoor apllications. This paper gives a basic data of electrodeless fluorescent lamp 'Endura'(OSRAM SYLVANIA ICETRON/ENDURA 150W). The experimetal system consist of ENDURA 150W/840 Coolwhite lamp and ENDURA 150/200-240 S ballast.

• Proceedings of the Korean Information Science Society Conference
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• 2003.10c
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• pp.706-708
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• 2003

무선 Ad­hoc 네트워크 환경에서는 제한된 자원의 효율적 사용을 고려하여야 한다. 그러한 중요 자원 중의 하나가 배터리로 공급되는 에너지원이다. 이 때 사용되는 총 에너지의 양을 최소화 하는 것도 중요하지만 경우에 따라서는 모든 노드들이 얼마나 지속적으로 서비스를 할 수 있는가가 중요한 요소가 될 수도 있다. 본 논문에서는 무선 Ad­hoc 네트워크에서 통신의 기본이 되는 브로드캐스팅을 위한 브로드캐스트 트리의 구성 시 모든 노드들이 에너지 소진으로 인한 작동의 멈춤 없이 최대한 활동할 수 있도록 하는 것을 고려한 트리 생성 방법을 제안한다.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.667-669
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• 2008

With the advancements or LEDs and lasers in projection display applications, arc lamps still provide the most cost effective solution to high brightness display systems. When will arc lamps become obsolete, will be of great importance today and tomorrow? Given the fact that traditional elliptical and parabolic reflectors had been around for decades; Wavien's new dual paraboloid reflector (DPR) technology with its unique imaging property enhances various aspects of the arc lamp performance will shed some light to this question. In this talk, various applications that are feasible today and anticipated needs of tomorrow will be presented.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.1769-1774
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• 2006

A fully integrated inline OLED production system is presented. The performance of PLED devices that are encapsulated with a thin film multilayer stack are compared to conventionally encapsulated devices with glas/dessicant protection. The observed luminance decay is the same in both cases. The lifetime performance of the thin film encapsulation is measured and critical parameters are discussed. The first smOLED devices produced on the OTB equipment are presented and comparison with other smOLED devices shows very good results.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.761-766
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• 2007

A brake disc is one of the key elements of friction brake system. Thermal cracks of discs may shorten the lifetime of a disc and increase maintenance cost. Therefore, prevention of thermal cracks is very important to ensure the safety of the vehicle operation and reduction of maintenance cost. In this study, the influence of parameters on the friction heat of brake disc is examined.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.23 no.59
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• pp.97-103
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• 2000

This study considers the design of life test sampling inspection plans by attributes for failure rate level qualification at selected confidence level. The lifetime distribution of products is assumed to be exponential. MIL-STD-690C and KS C 6032 standards provide this procedures. But these procedures have some questions to apply in the field. The cost of test and confidence level($1-{\beta}$ risk) are the problem between supplier and user. So, we suggest that the optimal life test sampling inspection plans using expected cost model considering product cost, capability, environmental test cost, etc.