• 제목/요약/키워드: probabilistic study

검색결과 1,458건 처리시간 0.028초

확률적 그래프 모델을 이용한 세포 간 정보 네트워크 추론 (Informatics Network Representation Between Cells Using Probabilistic Graphical Models)

  • 나상동;신현재;차월석
    • KSBB Journal
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    • 제21권4호
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    • pp.231-235
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    • 2006
  • 유전자 생물학 분야에서 적용가능 한 세포간 네트워크를 입증하는 고처리 정보공학에 응용하려는 수치학적인 표현 모델을 분석 연구한다. 확률적 그래프 모델을 사용하여 데이터 네트워크로부터 생물학적 통찰력을 확률적 함수적으로 응용해 복잡한 세포간 네트워크보다 단순한 하부모델로 구성하여 유전자 베이스네트워크 논리를 유전자 표현 레벨로 나타낸다. 유전자 데이터로부터 확률적 그래프 모델들을 분석하여 유전자 표현 데이터를 정보공학 네트워크 모델의 방법으로 확장 추론한다.

Bayesian demand model based seismic vulnerability assessment of a concrete girder bridge

  • Bayat, M.;Kia, M.;Soltangharaei, V.;Ahmadi, H.R.;Ziehl, P.
    • Advances in concrete construction
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    • 제9권4호
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    • pp.337-343
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    • 2020
  • In the present study, by employing fragility analysis, the seismic vulnerability of a concrete girder bridge, one of the most common existing structural bridge systems, has been performed. To this end, drift demand model as a fundamental ingredient of any probabilistic decision-making analyses is initially developed in terms of the two most common intensity measures, i.e., PGA and Sa (T1). Developing a probabilistic demand model requires a reliable database that is established in this paper by performing incremental dynamic analysis (IDA) under a set of 20 ground motion records. Next, by employing Bayesian statistical inference drift demand models are developed based on pre-collapse data obtained from IDA. Then, the accuracy and reasonability of the developed models are investigated by plotting diagnosis graphs. This graphical analysis demonstrates probabilistic demand model developed in terms of PGA is more reliable. Afterward, fragility curves according to PGA based-demand model are developed.

몬테카를로 시뮬레이션을 이용한 확률론적 파괴역학 수법의 적용성 검토 (Application of Probabilistic Fracture Mechanics Technique Using Monte Carlo Simulation)

  • 이준성;곽상록;김영진
    • 한국정밀공학회지
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    • 제18권10호
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    • pp.154-160
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    • 2001
  • For major structural components periodic inspections and integrity assessments are needed for the safety. However, many flaws are undetectable because sampling inspection is carried out during in-service inspection. Probabilistic integrity assessment is applied to take into consideration of uncertainty and variance of input parameters arise due to material properties and undetectable cracks. This paper describes a Probabilistic Fracture Mechanics(PFM) analysis based on the Monte Carlo(MC) algorithms. Taking a number of sampling data of probabilistic variables such as fracture toughness value, crack depth and aspect ratio of an initial surface crack, a MC simulation of failure judgement of samples is performed. for the verification of this analysis, a comparison study of the PFM analysis using a commercial code, mathematical method is carried out and a good agreement was observed between those results.

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축방향 관통균열이 존재하는 증기발생기 세관의 파손확률 예측 (Failure Probability Estimation of Steam Generator Tube Containing Axial Through-Wall Crack)

  • 문성인;이상민;배성렬;장윤석;황성식;김정수;김영진
    • 한국정밀공학회지
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    • 제22권10호
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    • pp.137-143
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    • 2005
  • The integrity of steam generator tubes in nuclear power plant should be maintained sufficiently during operation. For sake of this, complicated assessment procedures are required such as fracture mechanics analysis, etc. The integrity assessment of tubes has been performed by using conventional deterministic approaches while there are many uncertainties to carry out a rational evaluation. In this respect, probabilistic integrity assessment is considered as an alternative method for integrity assessment. The objectives of this study are to develop an integrity assessment system based on probabilistic fracture mechanics and to predict the failure probability of steam generator tubes containing an axial through-wall crack. The developed integrity assessment system consists of three evaluation modules, which apply first order reliability method, second order reliability method and Monte Carlo simulation method, respectively. The system has been applied to predict failure probability of steam generator tubes and the estimation results showed a promising applicability of the probabilistic integrity assessment system.

중학교 학생들의 확률적 사고 수준 평가 기준 개발 : 미국의 사례 (A Framework for Assessing Probability Knowledge and Skills for Middle School Students: A Case of U.S.)

  • 박지윤;이경화
    • 대한수학교육학회지:학교수학
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    • 제11권1호
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    • pp.1-15
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    • 2009
  • 일부 연구자들 (Jones et al., 1997; Tarr & Jones, 1977; Tarr & Lannin, 2005)은 학생들의 확률적 사고틀에 대해 연구해왔다. 이들 연구는 학생들의 확률적 사고 수준을 이해하는 도구를 제공하였다. 그러나 중학교 학생들의 확률적 사고 수준 관련 연구는 조건부 확률과 독립성 개념에만 머물러 있었다. 이 연구에서는 Jones et al.(1977), Polaki (2005), and Tarr and Jones(1977)의 연구를 분석하고, 미국의 교육과정과 국가 수준의 평가 자료를 분석하여 중학교 학생들의 확률적 사고 수준을 평가할 수 있는 틀을 개발한다.

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전과정평가에 있어 확률론적 건강영향분석기법 적용 -Part I : 전과정평가에 있어 확률론적 위해도 분석기법 적용방안에 관한 연구 (Application of Probabilistic Health Risk Analysis in Life Cycle Assessment -Part I : A General Framework for Uncertainty and Variability Analysis of Health Risk in Life Cycle Assessment)

  • 최광수;박재성
    • 환경영향평가
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    • 제9권3호
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    • pp.185-202
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    • 2000
  • Uncertainty and variability in Life Cycle Assessment(LCA) have been significant key issues in LCA methodology with techniques in other research area such as social and political science. Variability is understood as stemming from inherent variations in the real world, while uncertainty comes from inaccurate measurements, lack of data, model assumptions, etc. Related articles in this issues were reviewed for classification, distinguish and elaboration of probabilistic/stochastic health risk analysis application in LCA. Concept of focal zone, streamlining technique, scenario modelling and Monte Carlo/Latin Hypercube risk analysis were applied to the uncertainty/variability analysis of health risk in LCA. These results show that this general framework of multi-disciplinary methodology between probabilistic health risk assessment and LCA was of benefit to decision making process by suppling information about input/output data sensitivity, health effect priority and health risk distribution. There should be further research needs for case study using this methodology.

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확률적 타부 탐색 전략을 이용한 새로운 함수 최적화 방법에 관한 연구 (A Study on a New Function Optimization Method Using Probabilistic Tabu Search Strategy)

  • 김형수;황기현;박준호
    • 대한전기학회논문지:시스템및제어부문D
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    • 제50권11호
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    • pp.532-540
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    • 2001
  • In this paper, we propose a probabilistic tabu search strategy for function optimization. It is composed of two procedures, one is Basic search procedure that plays a role in local search, and the other is Restarting procedure that enables to diversify search region. In basic search procedure, we use Belief space and Near region to create neighbors. Belief space is made of high-rank neighbors to effectively restrict searching space, so it can improve searching time and local or global searching capability. When a solution is converged in a local area, Restarting procedure works to search other regions. In this time, we use Probabilistic Tabu Strategy(PTS) to adjust parameters such as a reducing rate, initial searching region etc., which makes enhance the performance of searching ability in various problems. In order to show the usefulness of the proposed method, the PTS is applied to the minimization problems such as De Jong functions, Ackley function, and Griewank functions etc., the results are compared with those of GA or EP.

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확률 기반 미등록 단어 분리 및 태깅 (Probabilistic Segmentation and Tagging of Unknown Words)

  • 김보겸;이재성
    • 정보과학회 논문지
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    • 제43권4호
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    • pp.430-436
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    • 2016
  • 형태소 분석시 나타나는 고유명사나 신조어 등의 미등록어에 대한 처리는 다양한 도메인의 문서 처리에 필수적이다. 이 논문에서는 3단계 확률 기반 형태소 분석에서 미등록어를 분리하고 태깅하기 위한 방법을 제시한다. 이 방법은 고유명사나 일반명사와 같은 개방어 뒤에 붙는 다양한 접미사를 분석하여 미등록 개방어를 추정할 수 있도록 했다. 이를 위해 형태소 품사 부착 말뭉치에서 자동으로 접미사 패턴을 학습하고, 확률 기반 형태소 분석에 맞도록 미등록 개방어의 분리 및 태깅 확률을 계산하는 방법을 제시하였다. 실험 결과, 제안한 방법은 새로운 미등록 용어가 많이 나오는 문서에서 미등록어 처리 성능을 크게 향상시켰다.

평면 FRAME 구조물의 확률유한요소 해석 (Probabilistic Finite Element Analysis of Plane Frame)

  • 양영순;김지호
    • 전산구조공학
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    • 제2권4호
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    • pp.89-98
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    • 1989
  • 구조해석에 사용되는 변수들이 갖고 있는 통계적 특성을 고려하기 위해 기존의 방법에서는 경험에 입각한 안전계수를 사용하여, 변수가 갖고 있는 불확실성을 정성적으로 취급하여 구조물의 안전성을 점검하여 왔다. 그러나, 최근 확률이론에 입각한 신뢰성이론을 적용하여 구조물의 안전성을 보다 정량적으로 파악하여 충분한 경험과 실적이 부족한 새로운 형태의 구조물의 안전성 점검에도 활용하려는 시도가 많이 이루어지고 있다. 이러한 추세에 따라, 본 연구에서는 기존의 유한요소법에 확률론적 수법을 가미한 확률 유한요소법을 개발하여, 구조해석에 사용되는 변수들이 갖고 있는 불확실량들이 구조해석의 최종결과에 어떤 영향을 미치는가를 확률적으로 처리하여, 구조물의 안전성을 보다 합리적으로 평가하도록 하였다.

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지진하중을 받는 마찰형 감쇠를 갖는 구조물의 변위 응답 확률 분포 (Probabilistic Distribution of Displacement Response of Frictionally Damped Structures under Earthquake Loads)

  • 이상현;박지훈;윤경조;민경원
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2007년도 정기 학술대회 논문집
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    • pp.639-644
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    • 2007
  • The accurate peak response estimation of a seismically excited structure with frictional damping system(FDS) is very difficult since the structure with FDS shows nonlinear behavior dependent on the structural period, loading characteristics, and relative magnitude between the frictional force and the excitation load. Previous studies have estimated that by replacing a nonlinear system with an equivalent linear one or by employing the response spectrum obtained based on nonlinear time history and statistical analysis. In the case that on earthquake load is defined with probabilistic characteristics, the corresponding response of the structure with FDS has probabilistic distribution. In this study, nonlinear time history analyses were performed for the structure with FDS subjected to artificial earthquake loads generated using Kanai-Tajimi filter. An equation for the probability density function (PDF) of the displacement response is proposed by adapting the PDF of the normal distribution. Finally, coefficients of the proposed PDF is obtained by regression analysis of the statistical distribution of the time history responses. Finally, the correlation between PDFs and statistical response distribution is presented.

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