• Title/Summary/Keyword: Reliability concept

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스위치야드 기기 신뢰도 군축방안 (Reliability Establishment Method of Switchyard Equipment)

  • 문수철;김건중
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2007년도 추계학술대회 논문집 전력기술부문
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    • pp.51-53
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    • 2007
  • The nuclear power plant uses the steam which occurs from reactor and T/G the drive. By the T/G in consequence of the fact that the electricity which is produced the power and supplies in transmission system. But, recently the transmission and generation system are placed under deregulation situation from domestic and foreign, the maintenance control is difficult with the accident or the breakdown which relates is increasing. Hereupon, considering for effect to the reactor core against trip element which it does apply a probability concept from the NRC of the United States and it study and the recognition for the importance of the switchyard which is a power equipment which will be revaluated. Hereupon using the American example, the reliability establishment method which is suitable in domestic and it searches it does.

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대형 액체로켓 추진기관 시스템 시험설비 개념설계 (Concept Design of the Propulsion System Test Complex for Heavy Liquid Rocket)

  • 김지훈;유병일;조남경;김승한;한영민
    • 한국추진공학회:학술대회논문집
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    • 한국추진공학회 2011년도 제37회 추계학술대회논문집
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    • pp.789-792
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    • 2011
  • 발사체의 비행시험을 하기 전 액체로켓 추진기관에 대한 지상시험 수행을 통해 효율적인 추진기관 개발을 도모할 수 있고 비행시험 전 검증을 통해 신뢰도를 높이고 개발비용도 절감할 수가 있다. 따라서 국내에서도 대형급 추진기관 시스템 시험설비를 구축함으로써 앞으로 개발되는 액체추진기관의 완성도와 신뢰도를 향상시켜 국제시장에서 경쟁력 있는 상용 발사체 개발의 첫걸음을 내딛을 수 있기를 기대한다.

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수면측정 도구의 개발을 위한 연구 (Development and Validation of Korean Sleep Scale A)

  • 오진주;송미순;김신미
    • 대한간호학회지
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    • 제28권3호
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    • pp.563-572
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    • 1998
  • The purpose of study was to develop and validate Korean Sleep Scale A which can be easily administrated by nurses for a wide range of adult subjects. Dimensions of sleep concept were derived by literature review. Previously developed sleep sclaes were also analyzed in order to develop scale items. The Korean sleep scale A was structured as a 15 item, 4 point likert type scale. The Scale was tested an 298 female and male adult subjects after pilottest and content validation. The results showed reliability by internal consistency of Cronbach's α=.75 Construct validity was tested by factor analysis and known group technique. Factor analysis showed 4 factors-sleep pattern, sleep evaluation, sleep result, and cause of sleep disturbance. These four factors explained 55.9% of total variance. Correlations between factors ranged from .15-.32. There was correlation among Korean Sleep ScaleA score, Verran and Snyder-Halpern(VSH) Sleep Scale score, and sleep satisfaction scale score, r=.71(p=.00), r=.51(p=.03), respectively, These study results partially support reliability, construct validity, and criterion related validity of Korean Sleep Scale A. Further validation study is required with other subjects and other settings.

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영성(Spirituality) 체험 - 기독교인 중심의 현상학적 접근 - (The Experience of Spirituality)

  • 오복자;강경아
    • 대한간호학회지
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    • 제31권6호
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    • pp.967-977
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    • 2001
  • This study explored and described the living spiritual experience and was attempted to gain an understanding of spirituality. This was done by eliciting participants′ verbal descriptions of their experiences. Method: Data was obtained from in-depth interviews with one cancer patient, one pastor, and three missionaries after obtaining informed consent from each. Interviews were tape recorded and transcribed verbatim. The transcripts were analyzed using Colaizzi′s phenomenological method. Sandelowski′s evaluation criteria for qualitative research, such as reliability, suitability and auditability, were also used to establish reliability and validity of this study. Result: The five major theme clusters that designated the essence of the spiritual experience, "spiritual awareness," "interconnectedness," "love," "tran- scendent energy," "purpose and meaning in life," emerged from the analysis. Conclusion: This study revealed that spirituality was activated by awareness through introspection and interconnectedness with a Supreme Being. The interconnectedness with a Supreme Being played an important role in harmonious relationships with others and self. It also resulted in revealing the other beneticial attributes of spirituality. Love, the core concept of the interconnectedness, worked as a transcendent energy. Also, the ability to see beyond reality and resulted in finding meaning in life and accomplishing well being.

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부품재활용이 허용될 때 목표운용가용도 조건을 갖는 소모성 동시조달부품의 구매량 결정 (Provisioning Quantity Determination of Consumable Concurrent Spare Part with Objective Availability Limitation under Cannibalization Allowed)

  • 오근태;김명수
    • 한국신뢰성학회지:신뢰성응용연구
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    • 제4권2호
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    • pp.91-104
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    • 2004
  • In this paper we consider the concurrent spare part(CSP) requirements problem of new equipment system. When a part fails, the part is replaced and the repair of failed part is impossible and cannibalization is allowed. We assume that the failure of a part knows a Poisson process. The operational availability concept in CSP is defined, and derive a formula to calculate the operational availability using expected machine operating time during CSP period. A mathematical model is derived for making an CSP requirement determination subject to the constraint of satisfying any given operational availability limitation and an heuristic solution search procedure is derived. An illustrative example is shown to explain the solution procedure.

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Wireless Audio-visual Interface over UWB

  • Cui, Wei
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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    • pp.1491-1494
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    • 2008
  • Typically internal mobile LCD display modules are connected to the mobile product baseband PCB with flexible printed circuit board equipped with board-to-board connector. This solution has a drawback of limiting the product concept work to certain solutions that are based on connector size, location, flexible PCB length, bending, etc. in the display module. Also flexible printed circuit board based solutions are not completely optimized from reliability point of view, causing flex circuit board breakings. For the external displays in the PC or Home entertainment market, the cable solution is too expensive and resource demanding. The wireless solution has obvious advantages over reliability, low cost and flexibility. This paper describes a wireless audio-visual interface solution.

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RAM 요소설계 목표값 연구 (A Study on the RAM Object Values)

  • 이한규;최진희
    • 한국군사과학기술학회지
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    • 제3권1호
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    • pp.218-230
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    • 2000
  • In the weapon system development/operation stage, the goals of RAM activities are to support the cost effective performance optimization in design and operation supports. In the study, the main contents are as follows; 1) To establish the operational concept and circumstance of the subsequent tank, the combat/operation scenario, the operational mode summary and mission profile for subsequent tank development are analyzed. 2) To evaluate the administrative and logistics down time for subsequent tank, the prefigured logistics circumstance and maintenance system are analyzed. 3) To calculate the RAM object values, a mathematical model for the user are developed. 4) To examinate the propriety of the RAM object values, the combat readiness are reviewed. The obtained RAM object values are provided to predict and analyze for the combat readiness, staying power, mission reliability, equipment availability and the logistic support capability.

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SCM415 침탄질화 처리재의 통계학적 피로거동에 대한 연구 (The Statistical study on the fatigue bebavior of Nitro -Carburized SCM415 steel)

  • 송삼홍;이상훈;임세혁
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1996년도 춘계학술대회 논문집
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    • pp.719-723
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    • 1996
  • In this research, The statistical characteristics of non-heated and nitro-carburized specimens are investigated under two stress levels (1.15 .sigma. $_{w}$ .leq. .sigma.$_{\alpha}$ .leq. 1.25 .sigma. $_{w}$). Seven specimens of each stress level are tested by rotary bending fatigue machine. The cycles about each crack length and crack propagation rate are used as statistical variagle of weibull distribution. By using concept of reliability function, reliable S-N formula of Nitro-Carburized specimen are gotten.ten.

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Optimal Maintenance Policy for Fishing Vessel Equipment Using Delay Time Analysis

  • Jung, Gi-Mun;Kwon, Young-Sub;Anand Pillay;Jin Wang
    • 한국신뢰성학회:학술대회논문집
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    • 한국신뢰성학회 2000년도 추계학술대회
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    • pp.329-333
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    • 2000
  • Delay time analysis is a pragmatic mathematical concept readily embraced by engineers which has been developed as a means to model maintenance decision problem. This paper considers an inspection period using delay time analysis for fishing vessel equipment. We assume that delay time distribution is Weibull and inspections are perfect. In this paper, we determine the optimal inspection period which minimize the expected downtime per unit time.

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SAFETY OF TRANSPORT SYSTEMS: MONITORING OF PREDICTING, FUNCTIONAL RELIABILITY PROVISION

  • Pavlovich, Khomenko Andrey;Viktorovich, Eliseev Sergey;Alekseevich, Djachenko Anatolij
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2007년도 추계학술대회 논문집
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    • pp.1913-1919
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    • 2007
  • Substantive provisions of the concept of an estimation and safety of complex technical systems are envisaged. New problems are assume orientation to use of the formalized methods of an estimation of residual resources of reliability of objects, and also development of other methodological base in creation of complex technical systems that is connected with detailed elaboration of attention to a safety at all stages of creation of systems: from designing until operation. In this connection existing large objects should be provided by the developed systems of engineering monitoring and diagnostics.

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