• 제목/요약/키워드: Safety Estimation

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필드고장을 이용한 신뢰성예측 프로그램 개발 (A Development of a Reliability Prediction Program Using the Field Failure)

  • 백재진;이광원
    • 한국자동차공학회논문집
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    • 제20권2호
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    • pp.1-7
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    • 2012
  • A Failure data from operating condition includes various failures. Reliability evaluation by operating condition is more correct than test condition. Additional, the evaluation result by operating condition is widely used for quality assurance, forecasting amount of manufacturing at EOL. To discover valuable things from the failure data, arrangement of the failure data and information technique to handle data is needed among many failure data. This paper introduces a reliability prediction program to solve this problem based on the failure. And new technologies for parameters estimation with method of Graphic-Wizard-Parameters-Estimation and Genetic Algorithm are introduced.

목포항의 수질특성 - 하계의 부영양화를 중심으로 - (The Characteristics of Water Quality in Mokpo Harbour(II) - Centering on eutrophication summer -)

  • 김광수
    • 해양환경안전학회지
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    • 제3권S1호
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    • pp.77-90
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    • 1997
  • the observations in situ and the seawater analyses were conducted in July and August, 1996 for the purpose of evaluating the characteristics of seawater quality centered on eutrophication in Mokpo harbour. By applying the OECD standards of trophic classification to the parameters such as secchi depth, total inorganic nitrogen, phosphate phosphorus and chlorophyll-a, the trophic level of seawater in Mokpo harbour was evaluated to be in eutrophic state in summer. By the estimation of pollution index with relation to eutrophication, the seawater quality of Mokpo harbour was evaluated to be under the regular grades and this evaluation was found to be different from the results of evaluation obtained by the environmental index of single parameter, chemical oxygen demand. By the estimation of eutrophication index, the seawaters of Mokpo harbour were shown to have the high potentiality of red tide occurrence.

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목포항의 수질특성(II) - 하계의 부영양화를 중심으로 - (The Characteristics of Water Quality in Mokpo Harbour(II) -Centering on eutrophication in summer-)

  • 김광수
    • 해양환경안전학회지
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    • 제3권2호
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    • pp.51-61
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    • 1997
  • The in situ observations and the seawater analyses were conducted in July and Auguse, 1996 for the purpose of evaluating the characteristics of seawater quality centered about eutrophication in Mokpo harbour. By applying the OECD standards of trophic classification to the parameters such as secchi depth, total inorganic nitrogen, phosphate phosphorus and chlorophyll-a, the trophic level of seawater in Mokpo harbour was evaluated to be in eutrophic state in summer. The estimation of pollution index by eutrophication showed the seawater quality of Mokpo harbour to deteriorate and fall under the regular grades. The results of eutrophic index estimation showed the high otentiality of red tide occurrence in Mokpo harbour.

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철도투자 및 운영을 위한 용량분석에 관한 연구 (Capacity Analysis for the Railway Investment and Operation)

  • 김동희;홍순흠;김재희
    • 대한안전경영과학회:학술대회논문집
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    • 대한안전경영과학회 2004년도 추계학술대회
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    • pp.197-203
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    • 2004
  • Railway system is consisted of various resources such as rail-line, signal, and railcar. It is necessary to efficiently utilize these limited and expensive resources as much as possible up to given line capacity. So far, we treat the line capacity as the criteria for evaluating investment alternatives or for restricting train frequencies, and this criteria is calculated statical and experimental numerical formula. But, line capacity has special attribute that changes dynamically according to operational conditions, so there is a need of new line capacity estimation system. In this paper, we present an improved systematic line capacity model. The proposed model has three main components ; TPS(lain performance simulator), PES(parameter evaluation simulator), LCS(line capacity simulator). The concept of each sub-component is described, including the evaluation method of capacity parameters. And capacity parameter evaluation and estimation results using sample line section data are presented.

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소표본인 경우 신뢰성 순위 척도의 고찰 (Overview of Reliability Rank Measures for Small Sample)

  • 최성운
    • 대한안전경영과학회지
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    • 제9권2호
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    • pp.161-169
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    • 2007
  • This paper presents three methods for expression of reliability measures for large and small data. First method is to express parametric estimation of cardinal reliability measure data for large sample, which requires numerous sample. Second is to obtain nonparametric distribution classification of ordinal reliability measure data for small sample. However it is difficult for field user to understand this method. Last method is to acquire parametric estimation of ordinal reliability measure data for small data. Because this method requires small sample and is comprehensive, we recommend this one among the proposed methods. Various reliability rank measures are presented.

Added Mass Estimation of Square Sections Coupled with a Liquid Using Finite Element Method

  • Jeong, Kyeong Hoon;Jhung, Myung Jo
    • Nuclear Engineering and Technology
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    • 제49권1호
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    • pp.234-244
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    • 2017
  • Natural frequencies of immersed square sections decrease due to a contribution of added mass to the movement of square sections. In this study, natural frequencies of square sections are obtained as a function of gap size between the square section and a rigid square wall using the finite element method. Additionally, they are used to extract the added mass effect on translational and rotation motions. Published information and studies on the translational and torsional vibration of square beams are also examined for practical use. D coupling of a square section is also investigated for multiple square sections. The suggested added mass estimation can be applicable to the spent fuel storage design of a pressurized light water modulated nuclear power plant.

접촉상태에 있는 초정밀 역전방지클러치의 내구성 평가에 관한 연구 (A Study on Endurance Estimation of ultra Precision Reverse-Locking Clutches under Contact Condition)

  • 서정세;이석순;이태선;최중환;이상범
    • 한국정밀공학회지
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    • 제22권6호
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    • pp.47-54
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    • 2005
  • A dangerous event occurred at the field industry and mechanical system. At developed by SUNGGOKNANOTECH corp. a R-L clutches of a small and high capacity serves safety device from a variety environment of mechanical system, it permits transmission of driving torque from input to output shaft in both directions of rotation, but restrains any feedback torque of the driven load from rotating the output shaft in either direction. This study was carried out to demonstrate through finite element method and durability estimation for safety of the R-L clutches without sliding during the engagement process. As results, we organized about endurance test method when applied rated torque.

Wavelet Power Spectrum Estimation for High-resolution Terahertz Time-domain Spectroscopy

  • Kim, Young-Chan;Jin, Kyung-Hwan;Ye, Jong-Chul;Ahn, Jae-Wook;Yee, Dae-Su
    • Journal of the Optical Society of Korea
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    • 제15권1호
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    • pp.103-108
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    • 2011
  • Recently reported asynchronous-optical-sampling terahertz (THz) time-domain spectroscopy enables high-resolution spectroscopy due to a long time-delay window. However, a long-lasting tail signal following the main pulse is often measured in a time-domain waveform, resulting in spectral fluctuation above a background noise level on a high-resolution THz amplitude spectrum. Here, we adopt the wavelet power spectrum estimation technique (WPSET) to effectively remove the spectral fluctuation without sacrificing spectral features. Effectiveness of the WPSET is verified by investigating a transmission spectrum of water vapor.

영남권 해양안전교육센터 구축을 위한 수요추정 (Demand estimation for the establishment of maritime safety education and training center in Youngnam region of Korea)

  • 임상섭
    • 한국컴퓨터정보학회:학술대회논문집
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    • 한국컴퓨터정보학회 2021년도 제63차 동계학술대회논문집 29권1호
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    • pp.327-328
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    • 2021
  • 본 논문은 2014년 세월호 사고 이후 해양재난사고에 대한 국민들의 경각심이 고조되었으며 해양레저인구증가로 인한 해양사고가 증가되는 상황에서 사고예방 및 해양안전문화 고취를 위한 해양안전교육센터 구축하고자 수요추정을 수행하였다. 특히, 우리나라 대부분의 해양안전체험관과 유사한 체험관들은 대부분 전라, 경기지역에 분포하고 있어 지역 편향을 해소하는 차원에서 동남권 안전센터 구축이 필요한 상황이며 해양레저 및 해양산업의 중심이 영남권에 위치하고 있기 때문에 안전교육센터의 구축의 정책적인 타당성이 있다. 본 논문에서는 해양안전교육센터 수요추정을 중력모형을 활용하여 수행하였으며 사회경제적인 타당성의 근거로서 활용이 가능할 것으로 기대된다.

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용담댐 발전소 접지설계를 위한 대지비저항 모델링 및 접지저항 추정 (Earth Resistivity Modelling and Grounding Resistance Estimation for Yongdam Dam Power Station Grounding Design)

  • 오민환;김형수;김종득
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1998년도 하계학술대회 논문집 C
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    • pp.1188-1191
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    • 1998
  • Detailed estimation of subsurface resistivity distribution and accurate estimation of actual fault current coming into the grounding system are indispensible to optimun grounding system design. Especially, it is essential for efficient grounding design to estimate subsurface resistivity distribution quantitatively and logically. Accurate estimation of subsurface resistivity distribution has an absolute influence on calculating touch voltage, step voltage and ground potential rise (GPR) which are related with grounding design standard for human safety. In this study, thirty-three electrical sounding surveys were made in Yongdam Power Station to obtain detailed subsurface resistivity distribution and the sounding data were interpreted quantitatively using multi-layered model. The results of the quantitative resistivity models were adopted practically to calculate grounding resistance values. Analytical asymptotic equations and CDEGS program were used in grounding resistance calculation and the results were compared and reviewed in the study.

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