• 한국농공학회지
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• 제32권E호
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• pp.59-66
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• 1990

Abstract The formulation of the probabilistic finite element method was briefly reviewed. The method was implemented into a computer program for frame analysis which has the same analogy as finite element analysis. Another program for Monte Carlo simulation of finite element analysis was written. Two sample structures were assumed and analized. The characteristics of the second moment statistics obtained by the probabilistic finite element method was examined through numerical studies. The applicability and limitation of the method were also evaluated in comparison with the data generated by Monte Carlo simulation.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 춘계 학술발표회
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• pp.475-479
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• 2010

For a rational evaluation of the spatial distribution of consolidation settlement, it is necessary to adopt probabilistic method. In this study, mean and standard deviation of consolidation settlement of whole analysis region are evaluated by using the spatial distribution of consolidation layer which is estimated from kriging and statistics of soil properties. Using these results and probabilistic method, the area need to be raised the ground level for balancing the final design ground level are determined.

• 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.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집A
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• pp.459-464
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• 2001

For major nuclear power plant components periodic inspections and integrity assessments are needed for the safety. But many flaws are undetectable due to sampling inspection. Probabilistic integrity assessment is applied to take into consideration of uncertainty and variance of input parameters arise due to material properties, applied load and undetectable flaws. This paper describes a Probabilistic Fracture Mechanics(PFM) analysis based on Monte Carlo(MC) algorithms. Taking important parameters as probabilistic variables such as fracture toughness, crack growth rate and flaw shape, failure probability of major nuclear power plant components is archived as a results of MC simulation. For the verification of these analysis, a comparison study of the PFM analysis using other commercial code, mathematical method is carried out and a good agreement was observed between those results.

• 한국안전학회지
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• 제18권2호
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• pp.98-103
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• 2003

Based on ASME probabilistic risk assessment (PRA) and NEI PRA peer review guidance, we evaluate a human reliability analysis (HRA) in probabilistic safety assessment (PSA) for Korea standard nuclear power plants, Ulchin Unit 3&4, to improve it performed at under design. The HRA for Ulchin Unit 3&4 is assessed as higher than Grade I based on ASME PRA standard and as higher than Grade 2 based on NEI PRA peer review guidance. The major items to be improved identified through the evaluation process are the documentation, the systematic human reliability analysis, the participitation of operators in the works and review of HRA. We suggest the guidance on the identification and qualitative screening analysis for pre-accident human errors and solve some items to be improved using the suggested guidance.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 A
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• pp.206-209
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• 2001

This paper illustrates a new method for reliability evaluation at load points in a composite power system. The algorithm includes uncertainties of generators and transmission lines as well as main transformers at substations. 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. 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 small test system.

• 한국안전학회지
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• 제25권6호
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• pp.186-196
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• 2010

It has been well known that traffic accidents occur under combined functional contributions of drivers, vehicles and road facilities, and that evaluation of safety levels for a specific road section or point is generally much complicated. Additionally, most of traffic accidents occur randomly implicating it is necessary to be evaluated in terms of probability theory. Thus, the evaluation model which reflects various characteristics and probabilistic distributions of traffic accidents has been necessary. The present paper provides a reliability based model with variables of probabilistic operating speeds and design speeds together which have been individually explaining associated characteristics in traffic accidents. Consequently, the model made it possible for speed management and road improvement projects to be evaluated in a common index. Application studies were performed in three cases. Through the studies, couples of facts were identified that the model successfully considered the probabilistic operating speeds and design speeds together and that then, the model evaluated road safety alternatives relatively which are complicatedly characterized and differently located.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.54-59
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• 2004

In this paper probabilistic fracture mechanics(PFM) approach is employed to evaluate the integrity of CANDU Zr-2.5Nb pressure tubes. Modified failure assessment diagram(Jr-FAD), plastic collapse, and critical crack length(CCL) approach are used for evaluating failure probability of the tubes. Jr-FAD was extended from the Kr-FAD because fracture of pressure tubes occurs in brittle manner due to hydrogen embrittlement of material by deuterium fluence. For developing the probabilistic integrity evaluation module, AECL procedures and fracture toughness parameters of EPRI were used.

• 한국정밀공학회지
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• 제22권10호
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• pp.158-166
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• 2005

Pressurized gas pipeline is subject to harmful effects both of the surrounding environment and of the materials transmitted in them. In order to maintain the integrity, reliable assessment procedures including tincture mechanics analysis etc are required. Up to now, the integrity assessment has been performed using conventional deterministic approaches even though there are many uncertainties to hinder a rational evaluation. In this respect, probabilistic approach is considered as an appropriate method for gas pipeline evaluation. The objectives of this paper are to estimate the failure probability of corroded pipeline in gas and oil plants and to propose limited operating conditions under different types of leadings. To do this, a probabilistic assessment program using reliability index and simulation techniques was developed and applied to evaluate failure probabilities of corroded API-5L-X52/X60 gas pipelines subjected to internal pressure, bending moment and combined loading. The evaluation results showed a promising applicability of the probabilistic integrity assessment program.

• 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.