• 제목/요약/키워드: Stochastic field

검색결과 216건 처리시간 0.024초

Development of New Management Prediction Support System based on Non-stochastic Model

  • Kaino, Toshihiro;Hirota, Kaoru;Mitsuta, Akimichi;Miura, Yasuyuki
    • 한국지능시스템학회:학술대회논문집
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    • 한국퍼지및지능시스템학회 2003년도 ISIS 2003
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    • pp.7-10
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    • 2003
  • In the field of financial technology, it is the U.S. initiative, and Japan is obliged to flattery in many respect. Currently Japan is in a too much defenseless situation that the economic structure is based on U.S. theory, In the conventional stochastic theory, it is also face that the prediction sometimes does not hit in the actual problem because it assumes a known probability distribution, none of which illustrates the real situation. A new research and development of management prediction support system is proposed based on fuzzy measures, that deals with the ambiguous, subjective evaluation by the people living in the real world well. Especially, the system will support venture, small and medium companies.

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STOCHASTIC SCALING EFFECT AND STATISTICS OF COSMOLOGICAL DENSITY FLUCTUATIONS

  • Yi, In-Su;Vsihniac, Ethan T.
    • 천문학논총
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    • 제7권1호
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    • pp.51-61
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    • 1992
  • The nonlinear stochastic behavior of chaotic inflation is characterized by the 'scaling' effect. Using a simple criterion for the appearance of scaling behavior in the ${\lambda}{\phi}^4$ inflation model, we show explicitly that in this limit the onset of the scaling regime does not require any special initial conditions and that it is independent of the self-coupling constant ${\lambda}$. Non-Gaussian statistics in adiabatic fluctuations are important only for super-horizon scales and the scaling regime does not lead to any significant statistical properties on currently observable scales. However, the scaling effect gives some cosmological consequences very different from what we expect in the naive diffusion approximation for quantum fluctuations. The classical (deterministic) treatment of the inflation field (essentially a quantum mechanical object.) becomes valid towards the end of inflation.

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Probabilistic stability analysis of underground structure using stochastic finite element method

  • Na, Sang-Min;Moon, Hyun-Koo
    • 한국지구물리탐사학회:학술대회논문집
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    • 한국지구물리탐사학회 2003년도 Proceedings of the international symposium on the fusion technology
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    • pp.192-197
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    • 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.

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추계학적 선진원 모델과 층상반무한체에서의 탄성파 전파 해석법에 의한 지진 지반운동 합성 (Synthesis of Earthquake Ground Motion by Combining Stochastic Line Source Model with Elastic Wave Propagation Analysis Method in a Layered Half Space)

  • 김재관;권기준
    • 한국강구조학회 논문집
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    • 제8권3호통권28호
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    • pp.97-105
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    • 1996
  • A Stochastic line source model is developed to simulate the seismic wave field generated during the rupture propagation process along a fault plane of which length is much larger than its width. The fault plane is assumed to consist of randomly distributed slip zones and barriers and each slip zone is modeled as a point source. By combining the newly developed source model with wave propagation analysis method in a layered 3-D visco-elastic half space, synthetic seismograms are obtained. The calculated accelerograms due to vertical dip slip and strike slip line sources are presented.

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Effect of cover cracking on reliability of corroded reinforced concrete structures

  • Chen, Hua-Peng;Nepal, Jaya
    • Computers and Concrete
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    • 제20권5호
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    • pp.511-519
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    • 2017
  • The reliability of reinforced concrete structures is frequently compromised by the deterioration caused by reinforcement corrosion. Evaluating the effect caused by reinforcement corrosion on structural behaviour of corrosion damaged concrete structures is essential for effective and reliable infrastructure management. In lifecycle management of corrosion affected reinforced concrete structures, it is difficult to correctly assess the lifecycle performance due to the uncertainties associated with structural resistance deterioration. This paper presents a stochastic deterioration modelling approach to evaluate the performance deterioration of corroded concrete structures during their service life. The flexural strength deterioration is analytically predicted on the basis of bond strength evolution caused by reinforcement corrosion, which is examined by the experimental and field data available. An assessment criterion is defined to evaluate the flexural strength deterioration for the time-dependent reliability analysis. The results from the worked examples show that the proposed approach is capable of evaluating the structural reliability of corrosion damaged concrete structures.

다확률변수를 고려한 불확정 지하구조계의 확률론적 유한요소해석 (Stochastic Finite Element Analysis of Underground Structure Considering the Multi-Random Variables in the Physical Properties of Rock mass)

  • 최규섭;정영수;황신일
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 1996년도 봄 학술발표회 논문집
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    • pp.173-181
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    • 1996
  • In this study, a stochastic finite element model is proposed with a view to consider the uncertainty of physical properties of rock mass in the analysis of structural behavior on underground caverns. Here, the Latin Hypercube Sampling technique, in which can makeup weak points of the Monte Carlo Simulation, is applied for the analysis of underground cavern. The validity of the newly developed computer program has been confirmed in terms of verification examples. And, the applicability of the program to the field has been tested in terms of the analysis of the underground oil storage cavern in korea.

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스테레오 비젼 및 영상복원 과정의 통합을 위한 확률 모형 (Stochastic Model for Unification of Stereo Vision and Image Restoration)

  • 우운택;정홍
    • 전자공학회논문지B
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    • 제29B권9호
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    • pp.37-49
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    • 1992
  • The standard definition of computational vision is a set of inverse problems of recovering surfaces from images. Thus the common characteristics of the most early vision problems are ill-posed. The main idea for solving ill-posed problems is to restrict the class of admissible solutions by introducing suitable a priori knowledge. Standard regurarization methods lead to satisfactory solutions of early vision problems but cannot deal effectively and directly with a few general problems, such as discontinuity and fusion of information from multiple modules. In this paper, we discuss limitations of standard regularization theory and present new stochastic method. We will outline a rigorous approach to overcome part of ill-posedness of image restoration, edge detection, and stereo vision problems, based on Bayes estimation and MRF(Markov random field) model, that effectively deals with the problems. This result makes one hope that this framework could be useful in the solution of other vision problems.

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교차주문을 갖는 리드타임 분포의 분석 (Analysis of Lead Time Distribution with Order Crossover)

  • 김기태
    • 산업경영시스템학회지
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    • 제44권4호
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    • pp.220-226
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    • 2021
  • In supply chain, there are a variety of different uncertainties including demand, service time, lead time, and so forth. The uncertainty of demand has been commonly studied by researchers or practitioners in the field of supply chain. However, the uncertainty of upstream supply chain has also increased. A problem of uncertainty in the upstream supply chain is the fluctuation of the lead time. The stochastic lead time sometimes causes to happen so called the order crossover which is not the same sequences of the order placed and the order arrived. When the order crossover happens, ordinary inventory policies have difficult to find the optimal inventory solutions. In this research, we investigate the lead time distribution in case of the order crossover and explore the resolutions of the inventory solution with the order crossover.

Non-Gaussian approach for equivalent static wind loads from wind tunnel measurements

  • Kassir, Wafaa;Soize, Christian;Heck, Jean-Vivien;De Oliveira, Fabrice
    • Wind and Structures
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    • 제25권6호
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    • pp.589-608
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    • 2017
  • A novel probabilistic approach is presented for estimating the equivalent static wind loads that produce a static response of the structure, which is "equivalent" in a probabilistic sense, to the extreme dynamic responses due to the unsteady pressure random field induced by the wind. This approach has especially been developed for complex structures (such as stadium roofs) for which the unsteady pressure field is measured in a boundary layer wind tunnel with a turbulent incident flow. The proposed method deals with the non-Gaussian nature of the unsteady pressure random field and presents a model that yields a good representation of both the quasi-static part and the dynamical part of the structural responses. The proposed approach is experimentally validated with a relatively simple application and is then applied to a stadium roof structure for which experimental measurements of unsteady pressures have been performed in boundary layer wind tunnel.

연성해석과 통계적 방법을 이용한 Butterfly Valve의 다목적 최적설계 (Multi-objective Optimization of Butterfly Valve using the Coupled-Field Analysis and the Statistical Method)

  • 배인환;이동화;박영철
    • 한국정밀공학회지
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    • 제21권9호
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    • pp.127-134
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    • 2004
  • It is difficult to have the existing structural optimization using coupled field analysis from CFD to structure analysis when the structure is influenced of fluid. Therefore in an initial model of this study after doing parameter design from the background of shape using topology optimization. and it is making a approximation formula using by the CFD-structure coupled-field analysis and design of experiment. By using this result, we conducted multi-objective optimization. We could confirm efficiency of stochastic method applicable in the scene of structure reliability design to be needed multi-objective optimization. And we presented a way of design that could overcome the time and space restriction in structural design such as the butterfly valve with the less experiment.