• Title/Summary/Keyword: probabilistic study

Search Result 1,458, Processing Time 0.034 seconds

An Efficient Learning Rule of Simple PR systems

  • Alan M. N. Fu;Hong Yan;Lim, Gi Y .
    • Proceedings of the Korean Institute of Intelligent Systems Conference
    • /
    • 1998.06a
    • /
    • pp.731-739
    • /
    • 1998
  • The probabilistic relaxation(PR) scheme based on the conditional probability and probability space partition has the important property that when its compatibility coefficient matrix (CCM) has uniform components it can classify m-dimensional probabilistic distribution vectors into different classes. When consistency or inconsistency measures have been defined, the properties of PRs are completely determined by the compatibility coefficients among labels of labeled objects and influence weight among labeled objects. In this paper we study the properties of PR in which both compatibility coefficients and influence weights are uniform, and then a learning rule for such PR system is derived. Experiments have been performed to verify the effectiveness of the learning rule.

  • PDF

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

  • Jang, Cheon-Soo;Park, Bum-Gyu;Kim, Chul-Su;Kim, Jung-Kyu
    • Proceedings of the KSME Conference
    • /
    • 2004.11a
    • /
    • pp.154-159
    • /
    • 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.

  • PDF

Probabilistic Analysis of Vertical Drains Using Spreadsheet (Spreadsheet를 이용한 연직배수공법의 확률론적 해석)

  • Kim, Seong-Pil;Heo, Joon;Yoon, Chang-Jin
    • Proceedings of the Korean Geotechical Society Conference
    • /
    • 2010.09a
    • /
    • pp.1024-1029
    • /
    • 2010
  • The conventional factor of safety as used in geotechnical engineering does not reflect the degree of uncertainty of the relevant parameters. Then in the geotechnical engineering, there have been efforts to reflect the uncertainties of the geotechnical properties through probabilistic analysis. In this study, a practical method for calculation the second moment reliability index using the optimization tool of a spreadsheet software is introduced. And this methodology was proposed by Low, B. K.(1996). The method is based on the perspective of an ellipsoid that just touches the failure surface in the original space of the variables. The method is applied to vertical drains(PVD) and compared with th result of Monte Carlo Simulation method.

  • PDF

A study on the Characteristics of Relationship Between Probabilistic Reliability and Supply Reserve Rate in Korea Power System (우리나라에서의 확률론적인 신뢰도와 공급예비율의 상관관계성에 관한 연구)

  • Park, Jeong-Je;Jeong, S.H.;Shi, B.;Wu, L.;Choi, J.S.;Yoon, Y.B.;Jung, Y.B.;Cha, J.M.;Yoon, Y.T.
    • Proceedings of the KIEE Conference
    • /
    • 2007.11b
    • /
    • pp.173-175
    • /
    • 2007
  • This paper introduces the characteristics of relationship between probabilistic reliability (LOLE; Loss of Load Expectation) and deterministic reliability (SRR; supply reserve rate) for 2008 year in Korea power system. Korea power system has been using the LOLE criterion to determine the adequacy of installed capacity (ICAP) requirement. The criterion is that load shall not exceed the avaliable capacity, on the average, more than five day in ten years. The probabilistic reliability evaluation and production cost simulation program which is called PPHFHT was used in order to obtain the relationship in this paper.

  • PDF

WEAK COMPATIBLE MAPPINGS OF TYPE (A) AND COMMON FIXED POINTS IN MENGER SPACES

  • Pathak, H.K.;Kang, S.M.;Baek, J.H.
    • Communications of the Korean Mathematical Society
    • /
    • v.10 no.1
    • /
    • pp.67-83
    • /
    • 1995
  • The notion of probabilistic metric spaces (or statistical metric spaces) was introduced and studied by Menger [19] which is a generalization of metric space, and the study of these spaces was expanede rapidly with the pioneering works of Schweizer-Sklar [25]-[26]. The theory of probabilistic metric spaces is of fundamental importance in probabilistic function analysis. For the detailed discussions of these spaces and their applications, we refer to [9], [10], [28], [30]-[32], [36] and [39].

  • PDF

Domestic Seismic Design Maps Based on Risk-Targeted Maximum- Considered Earthquakes (위험도기반 최대예상지진에 근거한 국내 내진설계 지도)

  • Shin, Dong Hyeon;Kim, Hyung-Joon
    • Journal of the Earthquake Engineering Society of Korea
    • /
    • v.19 no.3
    • /
    • pp.93-102
    • /
    • 2015
  • This study evaluates collapse probabilities of structures which are designed according to a domestic seismic design code, KBC2009. In evaluating their collapse probabilities, to do this, probabilistic distribution models for seismic hazard and structural capacity are required. In this paper, eight major cities in Korea are selected and the demand probabilistic distribution of each city is obtained from the uniform seismic hazard. The probabilistic distribution for the structural capacity is assumed to follow a underlying design philosophy implicitly defined in ASCE 7-10. With the assumptions, the structural collapse probability in 50 years is evaluated based on the concept of a risk integral. This paper then defines an mean value of the collapse probabilities in 50 years of the selected major cities as the target risk. Risk-targeted spectral accelerations are finally suggested by modifying a current mapped spectral acceleration to meet the target risk.

Adaptive Probabilistic Neural Network for Prediction of Compressive Strength of Concrete (콘크리트 압축강도 추정을 위한 적응적 확률신경망 기법)

  • 김두기;이종재;장성규
    • Proceedings of the Computational Structural Engineering Institute Conference
    • /
    • 2004.10a
    • /
    • pp.542-549
    • /
    • 2004
  • The compressive strength of concrete is commonly used criterion in producing concrete. However, the tests on the compressive strength are complicated and time-consuming. More importantly, it is too late to make improvement even if the test result does not satisfy the required strength, since the test is usually performed at the 28th day after the placement of concrete at the construction site. Therefore, accurate and realistic strength estimation before the placement of concrete is being highly required. In this study, the estimation of the compressive strength of concrete was performed by probabilistic neural network (PNN) on the basis of concrete mix proportions. The estimation performance of PNN was improved by considering the correlation between input data and targeted output value. Adaptive probabilistic neural network (APNN) was proposed to automatically calculate the smoothing parameter in the conventional PNN by using the scheme of dynamic decay adjustment algorithm. The conventional PNN and APNN were applied to predict the compressive strength of concrete using actual test data of a concrete company. APNN showed better results than the conventional PNN in predicting the compressive strength of concrete.

  • PDF

Probabilistic shear-lag analysis of structures using Systematic RSM

  • Cheng, Jin;Cai, C.S.;Xiao, Ru-Cheng
    • Structural Engineering and Mechanics
    • /
    • v.21 no.5
    • /
    • pp.507-518
    • /
    • 2005
  • In the shear-lag analysis of structures deterministic procedure is insufficient to provide complete information. Probabilistic analysis is a holistic approach for analyzing shear-lag effects considering uncertainties in structural parameters. This paper proposes an efficient and accurate algorithm to analyze shear-lag effects of structures with parameter uncertainties. The proposed algorithm integrated the advantages of the response surface method (RSM), finite element method (FEM) and Monte Carlo simulation (MCS). Uncertainties in the structural parameters can be taken into account in this algorithm. The algorithm is verified using independently generated finite element data. The proposed algorithm is then used to analyze the shear-lag effects of a simply supported beam with parameter uncertainties. The results show that the proposed algorithm based on the central composite design is the most promising one in view of its accuracy and efficiency. Finally, a parametric study was conducted to investigate the effect of each of the random variables on the statistical moment of structural stress response.

An Analysis for Delaminations Using Energy Release Rate in CFRP Laminates (에너지 해방률을 이용한 CFRP 적층복합재료의 층간분리 평가)

  • Gang, Gi-Won;Kim, Jeong-Gyu
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.24 no.8 s.179
    • /
    • pp.2115-2122
    • /
    • 2000
  • The understanding of impact-induced delamination is important in safety and reliability of composite structure. In this study, a model for arrest toughness is proposed in consideration of fracture behavior of composite materials. Also, the probabilistic model is proposed to describe the variability of arrest toughness due to the nonhomogeneity of material. For these models, experiments were conducted on the Carbon/Epoxy composite plates with various thickness using the impact hammer. The elastic work factor used in J-Integral is applicable to the evaluation of energy release rate. The fracture behavior can be described by crack arrest concept and the arrest toughness is independent of the delamination size. Additionally, a probabilistic characteristics of arrest toughness is well described by the Weibull distribution function. A variation of arrest toughness increases with specimen thickness.

Probabilistic stability analysis of underground structure using stochastic finite element method

  • Na, Sang-Min;Moon, Hyun-Koo
    • 한국지구물리탐사학회:학술대회논문집
    • /
    • 2003.11a
    • /
    • pp.192-197
    • /
    • 2003
  • It can be said that rock mass properties are characterized not by a mean value but by values with variation due to its characteristic uncertainty. This characteristic is one of the most important parts for the design of underground structures, but yet to be fully examined. Stochastic finite element method (SFEM) has been developed in order to take the randomness of structural systems into account. Using SFEM, the response variability of structural system can be obtained and it leads probabilistic stability of structure to be analyzed. In this study, displacements response variability of circular opening with hydrostatic stress field are analyzed in terms of rock mass properties having a certain mean and a standard deviation using the SFEM. The analyzed response variability shows that the necessity of probabilistic stability analysis of underground structures using reliable mean value and standard deviation of deformation modulus.

  • PDF