• Title/Summary/Keyword: Reliability Index(신뢰도 지수)

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Application of a New Reliability Index in Transmission Pricing (송전요율 결정을 위한 새로운 신뢰도 지수 산정에 관한 연구)

  • Lee, Won-Goo;Kim, Bai-Ho H.
    • Proceedings of the KIEE Conference
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    • 1999.11b
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    • pp.213-215
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    • 1999
  • This paper presents a transmission cost allocation through application of a new reliability index in transmission pricing in competitive electric industry. The proposed method allocates a fair use of transmission system charge given separately to individual generator by capacity usage, based on the contribution of individual generator considering N-1 contingency in reliability margin of transmission capacity, and offers more alternatives of pricing in using transmission capacity and transmission margin.

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Suggestion of Load and Resistance Factored Design Value for PHC Bored Pile (PHC 매입말뚝의 하중저항 설계정수 제안)

  • Park, Jong-Bae;Park, Yong-Boo;Lee, Bum-Sik;Kim, Sang-Yeon
    • Land and Housing Review
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    • v.3 no.3
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    • pp.279-286
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    • 2012
  • The limit states design method is replacing the allowable stress design method worldwide, e.g. the design code of ISO and various construction codes of Korea are adopting the reliability based limit state method. This paper proposed LRFD design value which is one of limit states design method for the PHC bored pile used as building foundation. This paper analysed 81 load test results and the bearing design(Meyerhof method & SPT-CPT conversion method), and proposed LRFD value for each design reliability Index 2.33 and 3.0 for PHC bored pile. LRFD value of PHC bored pile represents 0.36~0.44 for Meyerhof method and 0.24~0.31 for SPT-CPT conversion method according to the deign reliability index.

Relations of Safety Factor and Reliability for Pile Load Capacity (말뚝 기초지지력에 대한 안전율과 신뢰도지수 평가)

  • Kim, Dae-Ho;Kim, Min-Ki;Hwang, Sung-Uk;Park, Young-Hwan;Lee, Jun-Hwan
    • Journal of the Korean Geotechnical Society
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    • v.22 no.11
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    • pp.65-73
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    • 2006
  • Reliability between safety factor and reliability index for driven and bored pile load capacity was analyzed in this study. 0.1B, Chin, De Beer, and Davisson's methods were used for determining pile load capacity by using load-settlement curve from pile load test. Each method defines ultimate yield and allowable pile load capacities. LCPC method using CPT results was performed for comparing results of pile load test. Based on FOSM analysis using load factors, it is obtained that reliability indices for ultimate pile load capacity were higher than those of yield and allowable condition. Present safety factor 2 for yield and allowable load capacities is not enough to satisfy target reliability index $2.0{\sim}2.5$. However, it is sufficient for ultimate pile load capacity using safety factor 3.

Reliability Analysis of Ship′s Longitrdinal Strength for the Rational Ship Structural Design (선박구조설계 합리화를 위한 선체 종강도의 신뢰성 해석)

  • Oi-H. Kim;Byung-J. Kim
    • Journal of the Society of Naval Architects of Korea
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    • v.32 no.1
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    • pp.25-36
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    • 1995
  • The application of the reliability analysis is investigated as a probabilistic approach to the assessment of ship's structural strength and to the establishment of design format for longitudinal strength. Reliability analyses are carried out for 34 ships of tankers and bulk carriers built in HHI for some failure modes such as tensile yielding, compressive buckling and ultimate strength of hull girder. The safety assessment of each ship, the calculation of sensitivity factors and the derivation of target reliability index are performed. As results. the difference of reliability indices among ships is great for all modes. To provide more uniform levels of safety the establishment of new strength criteria using partial safety factors is performed. The partial safety factors for the design format are obtained according to the AFOSM method and the reliability-conditioned(RC) method. Finally, a design format using partial safety factors has been proposed. We could find out that new strength criteria can produce consistent reliability indices which are close to the target value.

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Reliability Analysis Modeling for LRFD Design of Bridge Abutments (LRFD 설계를 위한 교대의 신뢰성 해석 모델)

  • Eom, Jun-Sik
    • Journal of the Korean Geotechnical Society
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    • v.30 no.8
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    • pp.5-11
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    • 2014
  • The objective of this paper is to develop a rational reliability analysis procedure for the LRFD design provisions of bridge substructures. A bridge abutments is considered in this study. The reliability analysis is applied to determine the relationship between the major design parameters for bridge abutment and reliability index. The considered load components include dead load, vertical and horizontal earth pressure, earth surcharge, and vehicle live load. Several limit states are considered: foundation bearing capacity, sliding, and overturning. The analysis results show that the most important parameter in the reliability analysis is the effective stress friction angle of the soil. The reliability indices are calculated using Monte Carlo simulations for a selected bridge abutment. The results of the sensitivity analysis indicate that reliability index is most sensitive with regard to resistance factor and horizontal earth pressure factor.

Development of Reliability Index for Comparison of Components' Reliability (제품의 신뢰성 수준 비교를 위한 신뢰성 지수 개발)

  • Park, Jung-Won;Ham, Jung-Keol
    • Proceedings of the Korean Reliability Society Conference
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    • 2006.05a
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    • pp.140-148
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    • 2006
  • 본 논문에서는 선진 제품의 신뢰성 수준과 국산 제품의 신뢰성 수준 비교 결과를 정량적으로 표시하기 위한 신뢰성지수를 개발하여 제안하였다 본 연구에서 제안한 신뢰성지수는 가장 우수한 제품의 신뢰성수준과 비교하고자 하는 제품의 신뢰성 수준을 점수화한 신뢰성점수의 비로서 나타낸다. 이 때 신뢰성점수는 제품 초기 특성값 산포, 환경시험 후의 특성변화율, 제품 설계 여유도, 제품 수명 또는 고장률의 4가지 항목을 고려하여 미리 정한 점수 산출 기준을 통하여 산출한다. 제안한 신뢰성지수의 적용방법에 대한 이해를 돕기 위하여 구체적인 적용례도 함께 제시하였다.

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A Study on the Reliability Index and Customer Density of Distribution System (배전계통의 신뢰도 지수와 수용가 밀도에 관한 연구)

  • Bae, In-Su;Kim, Jin-O
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.9
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    • pp.1646-1650
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    • 2011
  • SAIDI(System Average Interruption Duration Index) is the index that signifies the power quality of customers. SAIDI is also used to know how well utilities operate their systems. The annual interruption time in the areas that consists of widely distributed customers, is generally longer than that in the areas that consists of heavily concentrated customers. The Reliability index of huge system is not necessarily better or worse than that of small system, because SAIDI is irrelevant to the total amount of power sold or the total number of customers. This paper proposes a customer density very relevant to SAIDI. The proposed customer density is used to modify the existing SAIDI to more clearly express the service level of power supply. A modified WSAIDI(weighted SAIDI) can be a useful indicator helping utilities improve the reliability of their systems and customers evaluate the service level of receiving power.

Calibration of Load and Resistance Factors in KCI Code Based on Domestic Data (국내 통계자료를 이용한 설계기준의 하중저항계수 검증)

  • Kim, Jee-Sang;Kim, Jong-Ho
    • Journal of the Korea Concrete Institute
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    • v.23 no.4
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    • pp.495-501
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    • 2011
  • The load combinations in current KCI Design Code are determined with reference to those in ACI 318-05, which adopts the LRFD (load and resistance factor design) format. The load and resistance factors in LRFD format should be determined to meet the required levels of reliability index or probability of failure for various predetermined failure modes, which are also based on the statistical data reflecting locality and contemporary situation. However, the current KCI Design Code has been written utilizing foreign data, because of insufficiency in accrued data in Korea. This study considered the current safety levels of KCI Code based on published domestic data to evaluate appropriateness of the current KCI regulations. Based on the calibrated reliability index of the existing Code, the new resistance factors are suggested. The results presented in this paper can be considered as a basic research for establishment of unique design format for future Korean Codes.

Reliability-based Redundancy Evaluation Method for Steel Plate Girder Bridges (신뢰도 기반 플레이트 거더교의 여유도 평가 기법)

  • Joe, Woom Do Ji;Park, Yong Myung;Jin, Seung Hoon;Hwang, Min Oh;Chung, Heung Jin
    • Journal of Korean Society of Steel Construction
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    • v.21 no.5
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    • pp.493-503
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    • 2009
  • Bridge redundancy is defined as the capability of a bridge to sustain loads after one of its main members incurs damage. It is affected by many parameters, including the number of girders, span length, girder height, internal supports, and secondary members. The present AASHTO and Korean Bridge design codes, however, define bridge redundancy only as the number of girders, and neither the evaluation method nor the required level of redundancy is given. This study presented a redundancy evaluation method for plate girder bridges with severe fatigue damage based on the reliability method,by considering the essential parameters. A required level of redundancy was also proposed as a target system reliability index from the load capacity analysis and reliability analysis of the basis bridge designed by LRFD. Finally, the level of redundancy of simple and continuous plate girder bridges with a variable number of girders designed by ASD was evaluated and presented.

Visualization of women's safety facility index based on public data analysis: Focusing on Seoul (공공데이터 분석 기반 여성안전 시설지수 시각화: 서울시 중심으로)

  • Kim, Hyeong-Gyun
    • Journal of Digital Convergence
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    • v.19 no.4
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    • pp.19-24
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    • 2021
  • In this paper, an index of women's safety facilities was created and visualized using public data related to Seoul. CPTED, the women's safety facilities index was created by collecting and analyzing eight data related to the local women's safety index and five major crime victims of women. As a result of the correlation analysis between the factors of the female safety facility index and the number of female crime victims, three data were selected as the main factors, "CCTV," "street lamps," and "female security guardians", which were found to be meaningful at the 95% level of reliability. The distinction women's safety facility index was calculated by weighting the correlation coefficient between the main factors for calculating the women's safety facility index, and visualized using Python's Follium library.