• Title/Summary/Keyword: reliablity analysis

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Reliability analysis for substation based on the failure rate data the facilities (설비의 고장을 데이터를 이용한 변전소 신뢰도 분석 연구)

  • Lee, Y.H.;Baek, D.H.;Jang, S.H.
    • Proceedings of the KIEE Conference
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    • 2006.07a
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    • pp.29-31
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    • 2006
  • The most crucial requirement of a power system is o supply quality electric energy to customers without interrution. This problem is directly related to reliability of power system. Reliability assessment of power system has been an important topic for the past several decades. This paper deals with reliability assessment of a 154kV power substation n KEPCO. In his paper, exponential distribution is used to calculate reliablity index. The failure rate data that are utilited for reliablity index based on the realistic system. Also, FTA(Fault Tree Analysis) is used to compute substation reliablity

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유압 관로망에서의 압력 맥동 해석법 개발

  • 이일영
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1996.04a
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    • pp.305-308
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    • 1996
  • An analyzing method for pressure fluctuation in oil hydraulic pipe network was developed in this study. The object pipe network has multi-branch configuration, and the pipeline of it is composed of steel tubes, flexible hoses. Also, accumulators, orifices and lumped oil volume components are attached on it. Transfer matrix method, in other words impedance method, was used for the analysis. The reliablity and usefulness of the analyzing method was confirmed by comparing and investigating computed results and experimental results got in this study.

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A Preliminary Study for the Standardization of the "Korean Maternal Behavior Inventory" ("어머니의 양육행동 척도" 표준화를 위한 예비 연구)

  • 박성연
    • Journal of the Korean Home Economics Association
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    • v.28 no.1
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    • pp.141-156
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    • 1990
  • The purpose of this study was to develop 『Korean Maternal Behavior Inverntory』(KMBI). The subjects were 712 mothers of 4th-6th grade elementary school children from 5 urban cities in Korea. Item analysis. Cronbach's α, Pearson's r, Factor analysis, and Percentile norms were conducted for the purpose of the study. The major findings were as follows; 1. By the method of item analysis and factor analysis, 51 items were selected for the scale of maternal behavior. 2. A factor analysis showed 7 factors(Reasoning guidance, Affect, Antliorian Control, Achievement, Overprotection, Active Involvement, Limit Setting) as separated domains from each others. 3. The reliablity coefficient of the scale was ranged from 62 to 81 sufficient to secure reliability. 4. Percentile ranks were drived from the total score and quartiles were calculted for the each of seven factor's scores. The present study presents a potentially highly useful way of measuring maternal behavior of 4th-6th grade elementary school children in Korea.

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A study on Optimum Design of the Frame for Mechanical Press (기계식 프레스 Frame의 최적설계에 관한 연구)

  • Jo, Baek-Hui;Ryu, Byeong-Sun
    • 연구논문집
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    • s.22
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    • pp.65-74
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    • 1992
  • This paper aims at calculating optimum design dimensions to minimize the weight satisfied strain and stress intensity of the frame while loading maximum weight into a mechanical press in the static condition. Analysis of the frame was carried out by using the FEM, then the optimum condition was obtained by using these data. As modeling in the finite element analysis has great impact on the reliablity of analysis results, the analyzed object was selected a 150-ton mechanical press of J Company, the part little affected to structural rigidity was simplified, the load condition was considered in the only maximum load, the boundary condition was used by giving symmetric displacement due to symmetric boundary condition, the finite element was applied a linear membrane element. An intermediate processor program applied the normal ANSYS to analyze finite elements was developed, and the design sensitivity was calculated. This program was applied to the optimum design.

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Effects of Facebook Advertisement Message's Convergence Type and SNS Trait on Brand Attitude, Purchasing Intention (페이스북 광고메시지의 융합형태와 SNS속성이 브랜드태도 및 구매의도에 미치는 영향)

  • Jeong, Chang-Jun
    • Journal of the Korea Convergence Society
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    • v.9 no.3
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    • pp.187-201
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    • 2018
  • Three types of Ad message convergence, A Letter, B Letter+Photo, C Letter+Photo+Video on the Facebook advertising were researched. For this research, three types of sample advertisements were tested on the 230 subjects. And the H1 - How do three types of advertisements differ on the SNS main trait, H2 - Among those Informativity, Reliablity, Playfulness, Intractivity as the SNS main trait, what is the more powerful factor on the brand attitude / Purchase Intention. For this research the ANOVA, Scheffe, Regression Analysis was used. As a result, H1 - The effect power of Playfulness and Interactivity on the three types of Ad message convergence ranked as "A

A Study on the Buffer Effects of Social Support on the Strain of the Aged (노인이 경험하는 긴장상태에 대한 사회적 지원의 완충효과 -노인의 생활만족도를 중심으로-)

  • 이신숙
    • Journal of the Korean Home Economics Association
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    • v.35 no.4
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    • pp.199-210
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    • 1997
  • The purpose of this study was to examine whether social support buffers the deleterious effects of strain on life satisfaction of the aged and to provide information for finding out ways of increasing their life satisfaction. The subjects of this study were 252 aged persons living in Kwangju and Joun-nam. The statistics used for data analysis were frequency percentage mean standard deviation reliablity Pearson's correlation multiple regression analysis through the SAS package program. 1) The support score from family was higher than the support from friends and the total point of life satisfaction of the aged was 28.4 which was above the median 24. 2) Social support especially the support from family buffer the negative effect of strain on life satisfaction of the aged. The result indicates that the family remains a supportive system for the aged parents Therefore A program in necessary for aged parents to promote the emotional solidarity between the aged parents and their children.

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A Study of Strength of Stress Block and Analysis of the Flexural Deformation for Concrete Structures (300kgf/$\textrm{cm}^2$, 500kg/$\textrm{cm}^2$, 700kgf/$\textrm{cm}^2$) using Reliablity Theory (신뢰성 이론을 이용한 (300kgf/$\textrm{cm}^2$, 500kg/$\textrm{cm}^2$, 700kgf/$\textrm{cm}^2$) 콘크리트 구조물의 휨변형 해석과 응력블럭의 선택에 관한 연구)

  • 최광진;장일영;송재호;홍원기
    • Proceedings of the Korea Concrete Institute Conference
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    • 1996.04a
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    • pp.334-339
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    • 1996
  • 본 연구의 목적은 불확실성이 내포되어 있는 콘크리트 구조물을 신뢰성 이론에 근거한 보통강도, 고강도 콘크리트에서의 휨모멘트-곡률관계와 하중변위관계를 해석하는데 그 목적을 두고 있다. 또한 기존의 해석방법과 본 연구에서의 해석방법을 비교하고 각 강도별로 기존에 제안된 응력블럭을 가정, 강도별에 알맞은 응력블럭을 검증하고 본 연구의 해석방버벵 대한 타당성을 증명하는 데 있다. 그래서 기존의 문헌을 통하여 공시체 데이터($\Phi$10$\times$20)에 대한 회귀분석을 이용하여 각 강도별로 곡선식을 모델화하여 제안하였고 이 식을 이용하여 불확실성을 내포하고 있는 몬테카롤로 시뮬레이션을 사용하여 내력을 평가하여 기존연구 해석치와 각 응력블럭을 이용한 본 연구에서의 해석치를 비교검토하여 이 해석방법의 타당성을 증명하는데 있다.

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Optimum Reliablity Based Design Criteria for Bridge Cassion Foundation (교량케이슨기초의 최적신뢰성 설계 규준)

  • 손용우;신형우;이증빈;정철원
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1992.10a
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    • pp.79-89
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    • 1992
  • This study is directed to propose a stability analysis and Design Criteria for Bridge Caisson foundations, with Could possibly replace the traditionals W.S.D. provisions of the Current Code, based on the FBOR(Load Factors based on optimum Reliability). The optimum reliability indices(Vertical bearing Capacity : $\beta$opt : 3.19, Lateral bearing Capacity : $\beta$opt= 3.15(ordinary), $\beta$opt : 2.93 (earthquake), Shearing resistance Capacity ; $\beta$opt : 2.87) are Selected as optimal Values Considering our practice base on the Calibration with the current Bridge Caisson foundation design Safety provisions, Load and resistance factors are measure by Using the proposed uncertainties and the Selected optimum reliability indices. furthermore, a set of nominal safety factors are proposed for the U.S.D. design provisions.

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Reliability Optimum Design of Slab System based on Lagrange Multipliers (Lagrange Multipliers에 의한 슬래브시스템의 신뢰성 최적설계)

  • Kim, Hyeon-Seak;Lee, Jeung-Bin;Jung, Chul-Won
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.1 no.1
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    • pp.113-124
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    • 1997
  • Based on the recent developments of the reliability-based structural analysis and design as well as the extending knowledge on the probabilistic characteristics of load and resistances, the probability based design criteria have been successfully developed for many standards. Since the probabilistic characteristics depend highly on the local load and resistances, it is recognized to develop the design criterion compatible with domestic requirements. The existing optimum design methods, which are generally based on the structural theory and certain engineering exprience, do not realistically consider the uncertainties of load and resistances and the basic reliability concepts. This study is directed to propose a optimum design based Expected Total Cost Minimization on two-way slab system which could possibly replace optimum design based traditional provisions of the current code, based on the AFOSM reliablity theory.

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