• 제목/요약/키워드: Life testing

검색결과 1,298건 처리시간 0.022초

순시전원품질 변화에 딱른 엘리베이터의 오동작에 관한 분석 (The analysis for malfunction of elevator equipment by instantaneous power quality)

  • 김기현;김종민;이건호;김선구;윤상욱
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2006년도 춘계학술대회 논문집 전기설비전문위원
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    • pp.34-36
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    • 2006
  • The number of confine-disease of elevator increases every year and then sudden rise, sudden stop, error of level indication, stand; those can bring to uneasiness of elevator passenger and malfunction accidents related life accident are increasing. For confirmation those malfunction accident, we are measuring and analyzing power quality(Sag, Interruption, Harmonic) of the actual site and evaluated the performance for stop and stating by testing the two imitation test equipment with EN12016(2004) standard level. This paper will be used data of the analysis for mutual relation between Power Quality and malfunction and fault of elevator.

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Improved Exponential Software Reliability Model Based on NHPP with the Uncertainty of Operating Environments

  • Song, Kwang Yoon;Chang, In Hong
    • 통합자연과학논문집
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    • 제10권4호
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    • pp.249-257
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    • 2017
  • The main focus when developing software is to improve the reliability and stability of a software system. We are enjoying a very comfortable life thanks to modern civilization, however, comfort is not guaranteed to us. Once software systems are introduced, the software systems used in the field environments are the same as or close to those used in the development-testing environment; however, the systems may be used in many different locations. Development of software system is a difficult and complex process. Generally, existing software reliability models are applied to software testing data and then used to make predictions on the software failures and reliability in the field. In this paper, we present an improved exponential NHPP software reliability model in different development environments, and examine the goodness-of-fit of improved exponential model and other model based on two datasets. The results show that the proposed model fits significantly better than other NHPP software reliability model.

보안 시스템 테스트를 위한 공격 발생 테스트슈트 구현 (Implementation of Attack Generation Test-Suite for Security System Testing)

  • 김환국;서동일;이상호
    • 한국사이버테러정보전학회:학술대회논문집
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    • 한국사이버테러정보전학회 2004년도 제1회 춘계학술발표대회
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    • pp.51-55
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    • 2004
  • 현재 인터넷은 이미 일상 생활에 깊게 자리 잡았다. 이러한 인터넷을 이용해서 실생활에서 수행하여야만 했던 많은 일들을 인터넷을 통해 수행할 수 있게 되었고, 인터넷의 편리함 때문에 인터넷 사용자가 늘어났다. 그러나 인터넷 사용자의 증가와 더불어 인터넷을 통한 각종 침해사고 역시 크게 증가하였다. 따라서, 이러한 침해 공격에 대응하는 보안 시스템 개발의 기능을 테스트하기 위해 다양한 공격 패턴과 트래픽을 자동적으로 발생시키는 공격 발생 테스트 슈트가 필요하다. 본 논문에서는 다중 에이전트를 이용하여 다양한 공격 패턴 발생 테스트슈트의 설계방법과 구현 결과를 기술하였다.

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Fatigue Crack Growth Behavior for Welded Joint of X80 Pipeline Steel

  • Kim, Young-Pyo;Kim, Cheol-Man;Kim, Woo-Sik;Shin, Kwang-Seon
    • 비파괴검사학회지
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    • 제29권1호
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    • pp.43-48
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    • 2009
  • The fatigue crack growth behavior of high strength X80 pipeline steel was investigated with compact tension specimens that crack growth directions were aligned either parallel or normal to the rolling direction of the pipeline. Also, the fatigue crack growth rates for welded joint of X80 pipeline steel were investigated with compact tension specimens that crack growth directions were aligned either parallel or normal to the welding line. The experimental results indicated the fatigue crack growth behavior was markedly different in three zones, weld metal, heat affected zone and base metal of welded joints. There was a trend toward increment in the fatigue life of weld metal and heat affected zone as compared with the X80 pipeline steel.

Empirical Statistical Power for Testing Multilocus Genotypic Effects under Unbalanced Designs Using a Gibbs Sampler

  • Lee, Chae-Young
    • Asian-Australasian Journal of Animal Sciences
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    • 제25권11호
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    • pp.1511-1514
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    • 2012
  • Epistasis that may explain a large portion of the phenotypic variation for complex economic traits of animals has been ignored in many genetic association studies. A Baysian method was introduced to draw inferences about multilocus genotypic effects based on their marginal posterior distributions by a Gibbs sampler. A simulation study was conducted to provide statistical powers under various unbalanced designs by using this method. Data were simulated by combined designs of number of loci, within genotype variance, and sample size in unbalanced designs with or without null combined genotype cells. Mean empirical statistical power was estimated for testing posterior mean estimate of combined genotype effect. A practical example for obtaining empirical statistical power estimates with a given sample size was provided under unbalanced designs. The empirical statistical powers would be useful for determining an optimal design when interactive associations of multiple loci with complex phenotypes were examined.

On-line Training of Neural Network for Monitoring Plant Transients

  • Varde, P.V.;Moon, B.S.;Han, J.B.
    • 한국지능시스템학회:학술대회논문집
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    • 한국퍼지및지능시스템학회 2003년도 춘계 학술대회 학술발표 논문집
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    • pp.129-133
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    • 2003
  • The work described in this paper deals with the proposed application of an Artificial Neural Network Model for the Advanced Pressurized Water Reactor APR-1400 transient identification. The approach adopted for testing the network take note of the expectation which should be fulfilled by a network for real-time application, like testing with data in on-line mode and use of actual or real-life patterns for training. The recall test performed demonstrates that use of neural network for transient identification is indeed an attractive preposition.

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기계.구조물의 경년열화와 수명평가기술 (Material Degradation and Life Assessment in Mechanical Equipment and Structure)

  • 김건영
    • 비파괴검사학회지
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    • 제19권2호
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    • pp.129-144
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    • 1999
  • 플랜트와 같은 장치산업은 내구성 구조물이므로 사용중에 열화가 발생하는 것은 필연적이다. 특히 고온, 고압의 부식환경하에서 사용되는 설비는 손상이 심하므로 가동중에 돌발적인 고장이 발생하여 플랜트의 가동을 중지하거나 파손사고가 일어나 생산손실은 물론 경우에 따라서는 안전사고의 발생, 환경오염 등 사회적인 문제를 일으키므로 이들 설비의 경년열화 실체를 충분히 이해하고 대책을 수립하는 것은 대단히 중요하다. 따라서 본고에서는 장치산업에서 발생하는 열화현상(재료의 연화, 경화 및 취화, 크리프, 피로, 부식, 마모 등)중 손상의 주류를 이루는 연화, 경화 및 취화, 크리프 피로에 대하여 기본적인 손상기구(damage mechanism)와 비파괴적 진단 및 평가 방법에 주안점을 두어, 현재 국내의 각종 플랜트 진단에 실용화된 기술을 해설하여 이 분야에 종사하는 관계자 여러분의 이해에 조금이라도 기여코자 한다.

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MEMS 디바이스의 고온고습 신뢰성시험 (High Temperature and High Humidity Test for MEMS Devices)

  • 이영규;박부희;장중순
    • 한국신뢰성학회지:신뢰성응용연구
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    • 제5권4호
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    • pp.487-500
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    • 2005
  • MEMS devices usually have micro actuators contained in a cavity, If the pressure level of testing chamber is higher than that of cavity, moisture will ingress into the cavity, which may cause critical failure such as stiction of the moving parts. To design an accelerated life test based on high temperature and high humidity, such a phenomena should be considered. In this study, a throughput model that can estimate the amount of moisture ingress is used to decide the testing time and conditions of a high temperature and high humidify test.

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Moment inequalities of $NBU_{mgf}$ with testing hypotheses application

  • Mahmoud, M.A.W.;Gadallah, A.M.
    • International Journal of Reliability and Applications
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    • 제13권2호
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    • pp.57-69
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    • 2012
  • Our goal in this paper is to establish inequalities for the moments of new better than used in the moment generating function class ($NBU_{mgf}$). Using these inequalities we propose a new test for exponentiality versus $NBU_{mgf}$ class. Pitman's asymptotic relative efficiency, power and critical values of this test are calculated to assess the performance of the test. We proposed also a new test for exponentiality versus $NBU_{mgf}$ in the right censored data. Sets of real data are used as an example to elucidate the use of the proposed test for practical problems.

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Performance optimization control of supersonic variable cycle engines

  • Tagashira, Takeshi;Sugiyama, Nanahisa
    • 한국추진공학회:학술대회논문집
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    • 한국추진공학회 2004년도 제22회 춘계학술대회논문집
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    • pp.779-783
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    • 2004
  • First this paper introduces an advanced FADEC (Full Authority Digital Electric Control) for current and future jet engines.It is designed to realize not only stable thrust control, but also performance improvement, reliability enhancement, service life extension, etc. It can be built by using current micro-processor with high computational power and there exists no difficulties but reliability problem of the micro- processor. Next, the simulation results of SFC minimization control are shown. The target engine is a supersonic, low-bypass ratio, 2-spool, combined cycle turbofan, designated as HYPR90T, which consists of a turbo engine for under Mach 3 flight and a ram engine for over Mach 3 flight. he results can then be used for performance optimization of the engine, which plays important role in the advanced FADEC.

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