• 제목/요약/키워드: Probabilistic reliability evaluation

검색결과 169건 처리시간 0.025초

Optimal Design of Inverse Electromagnetic Problems with Uncertain Design Parameters Assisted by Reliability and Design Sensitivity Analysis

  • Ren, Ziyan;Um, Doojong;Koh, Chang-Seop
    • Journal of Magnetics
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    • 제19권3호
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    • pp.266-272
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    • 2014
  • In this paper, we suggest reliability as a metric to evaluate the robustness of a design for the optimal design of electromagnetic devices, with respect to constraints under the uncertainties in design variables. For fast numerical efficiency, we applied the sensitivity-assisted Monte Carlo simulation (S-MCS) method to perform reliability calculation. Furthermore, we incorporated the S-MCS with single-objective and multi-objective particle swarm optimization algorithms to achieve reliability-based optimal designs, undertaking probabilistic constraint and multi-objective optimization approaches, respectively. We validated the performance of the developed optimization algorithms through application to the optimal design of a superconducting magnetic energy storage system.

원전 배관 결함의 크기측정성능에 대한 초음파 검사시스템의 확률론적 신뢰도 평가 (Probabilistic Reliability Analysis of Ultrasonic Inspection System about Sizing Performance of Defects in Piping on Nuclear Power Plant)

  • 김현묵;정지홍;지용우;장경영;박익근;박윤원
    • 한국신뢰성학회:학술대회논문집
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    • 한국신뢰성학회 2002년도 정기학술대회
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    • pp.217-224
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    • 2002
  • The performance demonstration round robin test was conducted to quantify the capability of ultrasonic inspection for in-service and to address some aspects of reliability for nondestructive evaluation. The fifteen inspection teams who employed procedures that met or exceeded ASME Sec. XI code requirements detected the piping of nuclear power plant with various cracks to evaluate the capability of detection. With data from PD-RR test, the performance of ultrasonic nondestructive inspection could be assessed using probability of length and depth sizing of cracks.

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풍력발전원과 다개 ESS를 고려한 제주도 계통에서의 신뢰도 평가 (Reliability Evaluation of Power system considering Wind Turbine Generators and Multi-Energy Storage System In JeJu Island)

  • 오웅진;임진택;이연찬;도응우옌대풍;최재석;윤용범;장병훈;조성민
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2015년도 제46회 하계학술대회
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    • pp.473-474
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    • 2015
  • This paper proposes probabilistic reliability evaluation model of power system considering Wind Turbine Generator(WTG) integrated with Energy Storage System(ESS). Monte carlo sample state duration simulation method is used for the evaluation. The power output from WTG units usually fluctuates randomly. Therefore, the power cannot be counted on to continuously satisfy the system load. Although the power output at any time is not controllable, the power output can be utilized when needed if ESS is available. The ESS may make to smooth the fluctuation of the WTG power output. The detail process of power system reliability evaluation considering Multi-ESS cooperated WTG is presented using case study of Jeju island power system in the paper.

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Monte Carlo법에 의한 복합전력계통의 유효부하지속곡선 작성법 및 개발 및 신뢰도 해석 (Development of the ELDC and Reliability Analysis of Composite Power System by Monte Carlo Method)

  • 문승필;최재석;신흥교;이순영;송길영
    • 대한전기학회논문지:전력기술부문A
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    • 제48권5호
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    • pp.508-516
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    • 1999
  • This paper presents a method for constructing composite power system effective load duration curves(CMELDC) at load points by Monte Carlo method. The concept of effective load duration curves(ELDC) in power system planning is useful and important in both HLII. CMELDC can be obtained from convolution integral processing of the probability function of unsupplied power and the load duration curve at each load point. This concept is analogy to the ELEC in HLI. And, the reliability indices (LOLP, EDNS) for composite power system are evaluated using CMELDC. Differences in reliability levels between HLI and HLII come from considering with the uncertainty associated with the outages of the transmission system. It is expected that the CMELDC can be applied usefully to areas such as reliability evaluation, probabilistic production cost simulation and analytical outage cost assessment, etc. in HLII, DC load flow and Monte Carlo method are used for this study. The characteristics and effectiveness of thes methodology are illustrated by a case study of the IEEE RTS.

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Probabilistic seismic assessment of mega buckling-restrained braced frames under near-fault ground motions

  • Veismoradi, Sajad;Darvishan, Ehsan
    • Earthquakes and Structures
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    • 제15권5호
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    • pp.487-498
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    • 2018
  • Buckling-restrained braces are passive control devices with high level of energy dissipation ability. However, they suffer from low post-yield stiffness which makes them vulnerable to severe ground motions, especially near-field earthquakes. Among the several methods proposed to improve resistance of BRB frames, mega-brace configuration can be a solution to increase frame lateral strength and stiffness and improve distribution of forces to prevent large displacement in braces. Due to the limited number of research regarding the performance of such systems, the current paper aims to assess seismic performance of BRB frames with mega-bracing arrangement under near-field earthquakes via a detailed probabilistic framework. For this purpose, a group of multi-story mega-BRB frames were modelled by OpenSEES software platform. In the first part of the paper, simplified procedures including nonlinear pushover and Incremental Dynamic Analysis were conducted for performance evaluation. Two groups of near-fault seismic ground motions (Non-pulse and Pulse-like records) were considered for analyses to take into account the effects of record-to-record uncertainties, as well as forward directivity on the results. In the second part, seismic reliability analyses are conducted in the context of performance based earthquake engineering. Two widely-known EDP-based and IM-based probabilistic frameworks are employed to estimate collapse potential of the structures. Results show that all the structures can successfully tolerate near-field earthquakes with a high level of confidence level. Therefore, mega-bracing configuration can be an effective alternative to conventional BRB bracing to withstand near-field earthquakes.

각 부하지점별 확률론적 발전비용 산정을 위한 수치해석적 방법 (Numerical Analysis Method for Nodal Probabilistic Production Cost Simulation)

  • 김홍식;문승필;최재석;노대석
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2001년도 춘계학술대회 논문집 전력기술부문
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    • pp.112-115
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    • 2001
  • This paper illustrates a new nodal effective load model for nodal probabilistic production cost simulation of the load point in a composite power system. The new effective load model includes capacities and uncertainties of generators as well as transmission lines. The CMELDC based on the new effective load model at HLII has been developed also. The CMELDC can be obtain from convolution integral processing of the outage capacity probabilistic distribution function of the fictitious generator and the original load duration curve given at the load point. It is expected that the new model for the CMELDC proposed. In this study will provide some solutions to many problems based on nodal and decentralized operation and control of an electric power systems under competition environment in future. The CMELDC based on the new model at HLII will extend the application areas of nodal probabilistic production cost simulation, outage cost assessment and reliability evaluation etc. at load points. The characteristics and effectiveness of this new model are illustrated by a case study of a test system.

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Probabilistic Reliability Evaluation of Power Systems Including Wind Turbine Generators Considering Wind Speed Correlation

  • Wu, Liang;Park, Jeong-Je;Choi, Jae-Seok;Ei-Keib, A.A.
    • Journal of Electrical Engineering and Technology
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    • 제4권4호
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    • pp.485-491
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    • 2009
  • The importance of renewable energy sources has been growing at a high rate as a result of being environment friendly. In particular, wind power is one of the most successfully utilized of such sources to produce electrical energy. Because of the randomness of wind speed, the reliability impact on this highly variable energy power is important aspect that needs to be assessed. In this paper, the impact on the reliability indices of wind speed correlation between two farms is considered.

구조계의 신뢰도해석을 위한 개선된 기법 (Improved Methods for Reliability Evaluations of Structural Systems)

  • 류정수;윤정방
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 1992년도 봄 학술발표회 논문집
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    • pp.51-57
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    • 1992
  • The primary objective of this study is the development of second moment methods for the efficient reliability evaluations of structural systems. Two methods are presented. One is the improved first order reliability method (IFORM), and the other is the modified probabilistic network evaluation technique (MPNET). For the purpose of verifying the proposed methods, example analyses are carried out on several cases with two failure modes, a plane frame structure involving three failure modes and simplified parallel member models for fatigue reliability evaluations of offshore structures. Numerical results indicate that the effectiveness of the proposed methods over the conventional ones (i.e., the FORM and the PNET) increases very significantly as the number of failure modes of the system increases.

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아스팔트 鋪裝道路의 確率論的 表層設計 (Pobabilistic Design of Asphalt Pavement Surface Courae)

  • 김광우;연규석
    • 한국농공학회지
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    • 제34권1호
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    • pp.66-77
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    • 1992
  • A prototype probabilistic approach to thickness design for asphalt pavement surface course was developed using first-order second moment probability model. The tensile strain (load effect) developing at the bottom of surface layer due to the wheel load and the critical strain (resistance) of asphalt concrete were used as random variables for pavement reliability analysis. Based on the parameters for load effect and resistance data collected from reference and field, simulated data were generated by Monte Carlo method for reliability evaluation of the pavement for a typical rural highway. Thickness of pavement surface course was defined in terms of target reliability of the pavement, growth factor of traffic, design life of pavement and resistance of the asphalt concrete to be placed on the pavement. According to these rationales, prototype thickness design chrats were sugested through example studies. From these, similar design charts can be developed for many pavements if appropriate data and target reliability are determined.

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소규모 냉각재 상실사고하의 원자로 압력용기에 대한 확률론적 파괴역학 평가 (Evaluation of Probabilistic Fracture Mechanics for Reactor Pressure Vessel under SBLOCA)

  • 김종욱;이규만;김태완
    • 한국압력기기공학회 논문집
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    • 제4권2호
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    • pp.13-19
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    • 2008
  • In order to predict a remaining life of a plant, it is necessary to select the components that are critical to the plant life. The remaining life of those components shall be evaluated by considering the aging effect of materials used as well as numerous factors. However, when evaluating reliability of nuclear structural components, some problems are quite formidable because of lack of information such as operating history, material property change and uncertainty in damage models. Accordingly, if structural integrity and safety are evaluated by the deterministic fracture mechanics approach, it is expected that the results obtained are too conservative to perform a rational evaluation of plant life. The probabilistic fracture mechanics approaches are regarded as appropriate methods to rationally evaluate the plant life since they can consider various uncertainties such as sizes and shapes of cracks and degradation of material strength due to the aging effects. The objective of this study is to evaluate the structural integrity for a reactor pressure vessel under the small break loss of coolant accident by applying the deterministic and probabilistic fracture mechanics. The deterministic fracture mechanics analysis was performed using the three dimensional finite element model. The probabilistic integrity analysis was based on the Monte Carlo simulation. The selected random variables are the neutron fluence on the vessel inside surface, the content of copper, nickel, and phosphorus in the reactor pressure vessel material, and initial RTNDT.

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