• Title/Summary/Keyword: Integration problems

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RELTSYS: A computer program for life prediction of deteriorating systems

  • Enright, Michael P.;Frangopol, Dan M.
    • Structural Engineering and Mechanics
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    • v.9 no.6
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    • pp.557-568
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    • 2000
  • As time-variant reliability approaches become increasingly used for service life prediction of the aging infrastructure, the demand for computer solution methods continues to increase. Effcient computer techniques have become well established for the reliability analysis of structural systems. Thus far, however, this is largely limited to time-invariant reliability problems. Therefore, the requirements for time-variant reliability prediction of deteriorating structural systems under time-variant loads have remained incomplete. This study presents a computer program for $\underline{REL}$iability of $\underline{T}$ime-Variant $\underline{SYS}$tems, RELTSYS. This program uses a combined technique of adaptive importance sampling, numerical integration, and fault tree analysis to compute time-variant reliabilities of individual components and systems. Time-invariant quantities are generated using Monte Carlo simulation, whereas time-variant quantities are evaluated using numerical integration. Load distribution and post-failure redistribution are considered using fault tree analysis. The strengths and limitations of RELTSYS are presented via a numerical example.

Simulation Modeling Approach for Integrating Distributed Simulation Objects on the Web (웹상에 분산된 시뮬레이션 객체들의 통합을 위한 시뮬레이션 모델링 방법론)

  • 이영해;심원보;김숙한;김서진
    • Journal of the Korea Society for Simulation
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    • v.9 no.4
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    • pp.25-40
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    • 2000
  • The cost of simulation modeling, the expertise required, and the pains of starting a new each time are impediments to more wide spread adoption of simulation technology. In addition, one of the most critical problems in the field of computer simulation today is the lack of published models and physical objects within the World Wide Web (WWW) allowing such distribution. From the viewpoint of WWW as distributed model repositories, it can be assumed that very many simulation models exist on the web. This paper is based on the premise that WWW is a distributed repository. Design Pattern, web-oriented technology like Java and CORBA, which are especially to cope with distributed objects, are introduced and discussed in detail for integration of simulation model. In this paper an architecture of model integration is proposed, which presents the whole procedure of model integration and how the Internet technologies are connected in. The central focus of this research is on the technical realization of integrating simulation models as distributed objects

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Integration of 3-Dim SPH Scheme into the ExLO Code (극대변형 해석을 위한 SPH 수치기법 개발 및 ExLO 코드 연계)

  • Lee, Min-Hyung;Cho, Young-Jun
    • Journal of the Korea Institute of Military Science and Technology
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    • v.14 no.3
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    • pp.532-537
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    • 2011
  • This paper describes the development of SPH(Smooth Particle Hydrodynamics) scheme and integration into the multi-material shock physics code(ExLO) for the purpose of the application to the extreme large deformation problems. SPH numerical scheme has been extended into the fluid dynamics and the high-speed impact events, such as space structure protection against space debris and meteorite catering. Like other hydrocodes, SPH scheme also solves the conservation equations with the constitutive equation including equation of state. The benchmark problem, Taylor-Impact test, was simulated and the predictions show good agreements with both the published numerical data and experimental data. Currently, the contact treatment between materials is under development.

An explicit time-integration method for damped structural systems

  • Pezeshk, S.;Camp, C.V.
    • Structural Engineering and Mechanics
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    • v.3 no.2
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    • pp.145-162
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    • 1995
  • A damped trapezoidal rule method for numerical time-integration is presented, and its application in analyses of dynamic response of damped structures is discussed. It is shown that the damped trapezoidal rule method has features that make it an attractive approach for applications in dynamic analyses of structures. Accuracy and stability analyses are developed for the damped single-degree-of-freedom systems. Error analyses are also performed for the Newmark beta method and compared with the damped trapezoidal rule method as a basis for discussion of the relative merits of the proposed method. The procedure is fully explicit and easy to implement. However, since the method is an explicit method, it is conditionally stable. The methodology is applied to several example problems to illustrate its strengths, limitations and inherent simplicity.

Computational Challenges for Integrative Genomics

  • Kim, Junhyong;Magwene, Paul
    • Genomics & Informatics
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    • v.2 no.1
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    • pp.7-18
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    • 2004
  • Integrated genomics refers to the use of large-scale, systematically collected data from various sources to address biological and biomedical problems. A critical ingredient to a successful research program in integrated genomics is the establishment of an effective computational infrastructure. In this review, we suggest that the computational infrastructure challenges include developing tools for heterogeneous data organization and access, innovating techniques for combining the results of different analyses, and establishing a theoretical framework for integrating biological and quantitative models. For each of the three areas - data integration, analyses integration, and model integration - we review some of the current progress and suggest new topics of research. We argue that the primary computational challenges lie in developing sound theoretical foundations for understanding the genome rather than simply the development of algorithms and programs.

Strategy for refinement of nodal densities and integration cells in EFG technique

  • Patel, Bhavana S.S.;Narayan, Babu K.S.;Venkataramana, Katta
    • Structural Engineering and Mechanics
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    • v.59 no.5
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    • pp.901-920
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    • 2016
  • MeshFree methods have become popular owing to the ease with which high stress gradients can be identified and node density distribution can be reformulated to accomplish faster convergence. This paper presents a strategy for nodal density refinement with strain energy as basis in Element-Free Galerkin MeshFree technique. Two popular flat plate problems are considered for the demonstration of the proposed strategies. Issue of integration errors introduced during nodal density refinement have been addressed by suggesting integration cell refinement. High stress effects around two symmetrical semi-circular notches under in-plane axial load have been addressed in the first problem. The second considers crack propagation under mode I and mode II fracture loading by the way of introducing high stress intensity through line crack. The computational efficacy of the adaptive refinement strategies proposed has been highlighted.

Limite of Integration and Discrimination of Paraguayan Inmigrants in Argentina (아르헨티나 거주 파라과이 이민자에 대한 차별과 통합의 한계)

  • Gu, Gyoungmo
    • Cross-Cultural Studies
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    • v.23
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    • pp.57-79
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    • 2011
  • This article has analyzed the limite of integration and discrimination of Paraguayan inmigrants in Argentina. The most numerous collectivity is the Paraguayan inmigrants, with about 325,046 members that reside mainly in the Gran Buenos Aires in 2001. Paraguayan inmigrantes and their families usually undergo abuses by security forces and the over exploitation and the illegal work to a large extent work informally and for low wages. They also point out numerous problems of discrimination with respect to access to the services of public of health, education and housing. For the reason, Argentine government has established the program of Patria Grande in April 17, 2006. This program is that issue a permanent residence and DNI for Latin American immigrants from bordering countries. But the Argentine government does not maintain the program Patria Grande. Paraguayan inmigrants are still situated in the increase of the ilegal work and social insecurity.

The Study on the Organizational Integration of the Information Related Operations in University (대학의 도서관과 전자계산소 및 관련기구의 조직 통합에 관한 연구)

  • 김성수;김윤실
    • Journal of the Korean Society for information Management
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    • v.14 no.1
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    • pp.125-159
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    • 1997
  • The purpose of the research was to investigate the organizational integration process of the university library, computer center and other informa ion related operations. The research process follows : first, the literature review of the organizational integration of the information related operations. second, analysis of the organizational integration in Korea. third, the organizational integration of information related operation in US and Japan, then the case analysis of information related organizational integrations in Korea. This process lead us to point out few problems and pitfalls that could occur in the integration procedure. The total integration procedure has turned out to be the most effective in the University environment. And for the management of fully integrated organization. Vice-President and Chief Information Officer, - who is reponsible to suggest vision, leadership and ability to cope with the complex nature of the future information society - was strongly suggested.

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Infinite Elements for Soil-Structure Interaction Anaysis (지반-구조물의 상호작용 해석을 위한 무한요소)

  • 양신추;윤정방
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1989.04a
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    • pp.22-27
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    • 1989
  • This paper presents a study of soil-structure interaction problems using infinite elements. The infinite elements are formulated for homogeneous and layered soil media, based on approximate expressions for three components of propagating waves, namely Rayleigh, compressive and shear waves. The integration scheme which was proposed for problems with single wave component by Zienkiewicz is expanded to the multi-wave problem. Verifications are carried out on rigid circular footings which are placed on and embedded in elastic half space. Numerical analysis is performed for a containment structure of a nuclear power plant subjected seismic excitation.

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An adaptive Control of the Nonholonomic Mobile AGV

  • Han, Zhe-Yong;Huh, Uk-Youl
    • Proceedings of the KIEE Conference
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    • 2001.11c
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    • pp.307-310
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    • 2001
  • Mobile AGV is one of the nonholon-omic systems. The integration of the kinematic adaptive controller for the dynamic in this pa-per introduction a motion control problem's dynamic state feedback as well as output feedback tracking laws will be constructed with the adaptive extension of the controller is proposed. Feedback control strategies for mobile AGV are important to compensate for disturabances and errors in the initial condition. The problems of path following or tracking and of stabilization about a constant configuration have been treated as separate problems for nonholonomic mobile AGV.

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