• 제목/요약/키워드: Probabilistic Curve

검색결과 154건 처리시간 0.024초

Probabilistic seismic risk assessment of simply supported steel railway bridges

  • Yilmaz, Mehmet F.;Caglayan, Barlas O.;Ozakgul, Kadir
    • Earthquakes and Structures
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    • 제17권1호
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    • pp.91-99
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    • 2019
  • Fragility analysis is an effective tool that is frequently used for seismic risk assessment of bridges. There are three different approaches to derive a fragility curve: experimental, empirical and analytical. Both experimental and empirical methods to derive fragility curve are based on past earthquake reports and expert opinions which are not suitable for all bridges. Therefore, analytical fragility analysis becomes important. Nonlinear time history analysis is commonly used which is the most reliable method for determining probabilistic demand models. In this study, to determine the probabilistic demand models of bridges, time history analyses were performed considering both material and geometrical nonlinearities. Serviceability limit states for three different service velocities were considered as a performance goal. Also, support displacements, component yielding and collapse limits were taken into account. Both serviceability and component fragility were derived by using maximum likely hood methods. Finally, the seismic performance and critical members of the bridge were probabilistically determined and clearly presented.

확률적 운전비계산 모형에 기초한 발전기 수입/순익 평가 방법론 개발 (An Efficient Revenue/Profit Evaluation Method Based on Probabilistic Production Costing Technique)

  • 박종배;신중린;김민수;전영환
    • 대한전기학회논문지:전력기술부문A
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    • 제51권12호
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    • pp.638-646
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    • 2002
  • This paper presents an efficient algorithm for evaluating the Profit and revenue of generating units in a competitive electricity market based on the probabilistic production costing technique. The accurate evaluation of the profit and revenue of generating units for long-term perspectives is one of the most important issues in a competitive electricity market environment. For efficient calculation of the profit and revenue of generating units under the equivalent load duration curve(ELDC), a new approach to figure out the marginal plants and the corresponding market clearing prices during a time period in a probabilistic manner is developed. The mathematical formulation and illustrative application of the suggested method is presented.

가압열충격에 대한 원자로 용기의 확률론적 파괴역학해석 - 잔류응력 및 파괴인성곡선의 영향 - (Probabilistic Fracture Mechanics Analysis of Reactor Vessel for Pressurized Thermal Shock - The Effect of Residual Stress and Fracture Toughness -)

  • 정성규;진태은;정명조;최영환
    • 대한기계학회논문집A
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    • 제27권6호
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    • pp.987-996
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    • 2003
  • The structural integrity of the reactor vessel with the approaching end of life must be assured for pressurized thermal shock. The regulation specifies the screening criteria for this and requires that specific analysis be performed for the reactor vessel which is anticipated to exceed the screening criteria at the end of plant life. In case the screening criteria is exceeded by the deterministic analysis, probabilistic analysis must be performed to show that failure probability Is within the limit. In this study, probabilistic fracture mechanics analysis of the reactor vessel for pressurized thermal shock is performed and the effects of residual stress and master curve on the failure probability are investigated.

각 부하지점별 유효부하지속곡선 작성법에 관한 연구 (A Study on Construction of the CMELDC at Load Points)

  • 김홍식;문승필;최재석
    • 대한전기학회논문지:전력기술부문A
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    • 제49권4호
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    • pp.195-198
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    • 2000
  • This paper illustrates a new method for constructing composite power system effective load duration curve(CMELDC) at load points. The main concept of proposed method is that the CMELDC can be obtain from convolution integral processing of the outage probabilistic distribution function of not supplied power and the load duration curve given at each load point. The effective load duration curve (ELDC) at HLI plays an important part in probabilistic production simulation, reliability evaluation, outage cost assessment and power supply margins assesment for power system planning and operation. And also, the CMELDC at HLII will extend the application areas of outage cost assessment and reliability evaluation at each load point. The CMELDC at load points using the Monte Carlo method and a DC load flow constrained LP have already been developed by authors. The effective load concept at HLII, however, has not been introduced sufficiently in last paper although the concept is important. In this paper, the main concept of the effective load at HLII which is proposed in this study is defined in details as the summation of the original load and the probabilistic loads caused by the forced outage of generators and transmission lines at this load point. The outage capacity probabilistic distribution function at HLII can be obtained by combining the not supplied powers and the probabilities of the not supplied powers at this load point. It si also expected that the proposed CMELDC can be applied usefully to research areas such as reliability evaluation, probabilistic production cost simulation and analytical outage cost assessment, etc. at HLII in future. The characteristics and effectiveness of this methodology are illustrated by case study of IEEE-RTS.

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폴리아세탈 소재의 확률론적 변형률-수명선도 평가 (An Evaluation of Probabilistic Strain-Life Curve in Polyacetal)

  • 장천수;김철수;박범규;김정규
    • 대한기계학회논문집A
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    • 제30권11호
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    • pp.1417-1424
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    • 2006
  • In order to evaluate variation of fatigue life of mechanical components including engineering plastics, it is important to estimate probabilistic strain-life curves to accurately define the variation of fatigue characteristics. This paper intends to provide new assessment of P-$\varepsilon$-N (probabilistic strain-life curves) for considering the variation of fatigue characteristics in polyacetal. The fatigue strain controlled tests were conducted under constant 50% humidity and room temperature condition by a universal testing machine at strain ratio, R=0. A practical procedure is introduced to evaluate probabilistic strain-life curves. Three probabilistic distributions were used for generating P-$\varepsilon$-N curves such as normal, 2-parameter and 3-parameter Weibull. In this study, 3-parameter Weibull distribution was found to be most appropriate among assumed distributions when the probability distributions of the fatigue characteristic were examined using chi-square and Kolmogorov-Smirnov test. The more appropriate P-$\varepsilon$-N curves for these materials are generated by the proposed method considering 3-parameter Weibull distribution.

확장된EIGC법에 의한 확업적 발전비 게산에 관한 연구 (A Study on the Probabilistic Production Cost Calculation by the Developed EIGC Method.)

  • 송길영;최재석;김용하
    • 대한전기학회논문지
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    • 제36권12호
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    • pp.839-847
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    • 1987
  • The probabilistic production cost is calculated by the Expected Incremental Generation Cost Curve(EIGC) method based on the multi-state and multi-block operating conditions. For this, A new algorithm for determining production cost by the EIGC and the generation availability curve (GAC) had been developed in order to realize better economic olad dispatch and better reliability for power system operation. The simpler method for determining the EIGC and the GAC is proposed for convenience and saving in computation time.

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각 부하지점별 확률론적 발전비용 산정을 위한 수치해석적 방법의 개발 (Development of a New Numerical Analysis Method for Nodal Probabilistic Production Cost Simulation)

  • 김홍식;문승필;최재석;노대석;차준민
    • 대한전기학회논문지:전력기술부문A
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    • 제50권9호
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    • pp.431-439
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    • 2001
  • This Paper illustrates a new numerical analysis method using a 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(composite power system effective load duration curve) based on the new effective load model at HLll(Hierarchical Level H) has been developed also. The CMELDC can be obtained 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 HLll 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 MRBTS(Modified Roy Billinton Test System).

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제방의 취약도 곡선 작성을 위한 실용적 신뢰성 해석의 적용성 (Applicability of Practical Reliability Analysis to Develop Fragility Curves for Levee)

  • 조성은
    • 한국지반공학회논문집
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    • 제38권11호
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    • pp.19-30
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    • 2022
  • 하천제방의 취약도 곡선을 구하기 위해서는 수위에 따른 파괴확률을 각 파괴모드 별로 구해야 한다. 확률론적 해석은 지반공학적 확률변수의 변동성을 고려하기 위하여 반복적인 해석을 필요로 하므로 취약도 곡선을 구하는 작업은 많은 반복 계산을 필연적으로 수반한다. 실제 제방의 취약도 곡선 작성에서는 계산량을 줄이기 위하여 단순화된 확률론적 해석기법을 적용하고 있으나 그 정확성에 대한 명확한 평가는 없는 형편이다. 본 연구에서는 실제 하천제방을 대상으로 확률론적인 방법에 의해 사면안정과 파이핑에 대한 파괴확률을 계산하여 제방의 안전도를 평가하고 수위에 따른 제방의 취약도 곡선을 구하였다. 이때 간략법인 FOSM과 PEM의 결과를 MCS의 결과와 비교하여 사면안정과 파이핑 파괴모드의 취약도 곡선 작성에 대한 적용성을 평가하였다.

엔지니어링 플라스틱 소재의 피로특성에 대한 응용프로그램 개발 (Development of Application Program for Fatigue Characteristics of Engineering Plastics)

  • 장천수;박범규;김철수;김정규
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2004년도 추계학술대회
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    • pp.154-159
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    • 2004
  • In this study, in order to perform more efficiently reliability design and integrity assessment of structural members, the relational database management program on the engineering plastics was constructed. This program contained 476 grades for 14 kinds of the engineering plastics and was developed using MS-access and MS-visualbasic. This program consists of 3 modules; search condition, probabilistic characteristics of material property, evaluation of P-S-N curve. We perform fatigue test for probabilistic durability analysis and this results input the database program to estimate P-S-N.

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최대원리에 의한 화력-양수발전시스템의 확률적 운전시뮬레이션 모델 (Probabilistic Optimal Weekly Coordination of Thermal-Pumped Storage Power System based on the Maximum Principle)

  • 이봉용;심건보
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1991년도 하계학술대회 논문집
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    • pp.411-416
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    • 1991
  • Operation simulation is a key factor to evaluate investment and operation in a power utility. Probabilistic production simulation is of major concern. With pumped-storage plant, production simulation is not an easy task, because its economy should fully be exploited. In addition, usual operation interval is a week rather than a day. Most existing models are based on approximate production simulation such as adopting simple priority orders of generations. This study is based on the more elaborate model developed by authors. Further, a policy of weekly coordination is established based on the Maximum Principle. Chronological load curve instead of usual load duration curve is used and the accuracy in simulation is enhahced. Resulting economics are compared. Deviation between these two toad curve is shown.

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