• Title/Summary/Keyword: continuum model

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A Study on the Information Continuum Model: Preliminary Analysis to Establish the Relationship Between Records and Information (정보 컨티뉴엄 모델에 관한 연구: 기록과 정보 간의 관계 정립을 위한 예비적 분석)

  • Kim, Myoung-hun
    • Journal of Korean Society of Archives and Records Management
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    • v.22 no.3
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    • pp.21-36
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    • 2022
  • This study intends to analyze the information continuum model as part of establishing the relationship between records and information. The information continuum is a theoretical system designed to establish a new information concept from the record-keeping point of view based on the record continuum. It provides a conceptual framework that can identify the elements for information management that exist in record-keeping. Accordingly, in Chapter 2, the background and process of the information continuum development, which followed after the record continuum development, were reviewed. Then, the concept of information established by borrowing information science theory was examined in relation to the record continuum. In Chapter 3, the conceptual structure of the information continuum and the purpose and method of information utilization were considered. Afterward, the four dimensions and attributes that structurally schematize the elements for information management in record-keeping were analyzed. Based on this analysis, Chapter 4 tried to present the meaning and limitations of the information continuum.

Continuum Model considering Surface Effect for Thin film (박막구조해석을 위한 표면효과를 고려하는 연속체 모델)

  • Choi, Jin-Bok;Jung, Kwang-Sub;Cho, Maeng-Hyo
    • Proceedings of the KSME Conference
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    • 2007.05a
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    • pp.527-531
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    • 2007
  • The classical continuum theory-based thin film model is independent of their size and the surface effect can be ignored. But the surface to bulk ratio becomes very large in nano-size structures such as nano film, nano wire and nano beam. In this case, surface effect plays an important role and its contribution of the surface effect must be considered. Molecular dynamics simulation has been a conventional way to analyze these ultra-thin structures but structures in the range between submicro and micro are difficult to analyze by classical molecular dynamics due to the restriction of computing resources and time. Therefore, in present study, the continuum-based method is considered to predict the overall physical and mechanical properties of the structures in nano-scale, especially, for the thin-film. The proposed continuum based-thin plate finite element is efficient and reliable for the prediction of nano-scale film behavior.

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A Methodology to Formulate Stochastic Continuum Model from Discrete Fracture Network Model and Analysis of Compatibility between two Models (개별균열 연결망 모델에 근거한 추계적 연속체 모델의 구성기법과 두 모델간의 적합성 분석)

  • 장근무;이은용;박주완;김창락;박희영
    • Tunnel and Underground Space
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    • v.11 no.2
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    • pp.156-166
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    • 2001
  • A stochastic continuum(SC) modeling technique was developed to simulate the groundwater flow pathway in fractured rocks. This model was developed to overcome the disadvantageous points of discrete fracture network(DFN) modes which has the limitation of fracture numbers. Besides, SC model is able to perform probabilistic analysis and to simulate the conductive groundwater pathway as discrete fracture network model. The SC model was formulated based on the discrete fracture network(DFN) model. The spatial distribution of permeability in the stochastic continuum model was defined by the probability distribution and variogram functions defined from the permeabilities of subdivided smaller blocks of the DFN model. The analysis of groundwater travel time was performed to show the consistency between DFN and SC models by the numerical experiment. It was found that the stochastic continuum modes was an appropriate way to provide the probability density distribution of groundwater velocity which is required for the probabilistic safety assessment of a radioactive waste disposal facility.

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On the continuum formulation for modeling DNA loop formation

  • Teng, Hailong;Lee, Chung-Hao;Chen, Jiun-Shyan
    • Interaction and multiscale mechanics
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    • v.4 no.3
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    • pp.219-237
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    • 2011
  • Recent advances in scientific computing enable the full atomistic simulation of DNA molecules. However, there exists length and time scale limitations in molecular dynamics (MD) simulation for large DNA molecules. In this work, a two-level homogenization of DNA molecules is proposed. A wavelet projection method is first introduced to form a coarse-grained DNA molecule represented with superatoms. The coarsened MD model offers a simplified molecular structure for the continuum description of DNA molecules. The coarsened DNA molecular structure is then homogenized into a three-dimensional beam with embedded molecular properties. The methods to determine the elasticity constants in the continuum model are also presented. The proposed continuum model is adopted for the study of mechanical behavior of DNA loop.

Developing Higher-Order Continuum Models for Describing Traffic Flow Behavior at Lane Drops Using Momentum Equation (Momentum Equation을 이용한 차로감소구간 교통류의 Higher-Order Continuum 모형 개발)

  • 손영태;양충헌;박우신
    • Journal of Korean Society of Transportation
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    • v.20 no.2
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    • pp.93-104
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    • 2002
  • The purpose of this study was to develop a improved high-order continuum model among macroscopic traffic flow models. This study was mainly performed for uninterrupted flow. In the first step, the proposed model described traffic flow at dropped lane. (no exits) It was possible to describe the traffic flow during short-term considering lane change. The proposed model was based on Payne's model. Our model was newly applied to uninterrupted traffic flow in consideration of geometry condition and driver behavior. It is possible to establish efficient control strategies, simulation and assess the effects of geometric improvements using this model. This model was simulated with field data for the actual adaption. The results of the model tests, traffic volume and density is suitably represented. we think that the results in the article can be led to predicting the situation in the near future.

An Equivalent Truss Model by Discretizing Continuum Structure (연속체의 이산화에 의한 등가트러스모델 개발)

  • Lee, Sung-Yong;Kim, Tae-Gon;Lee, Jeong-Jae
    • Journal of The Korean Society of Agricultural Engineers
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    • v.51 no.3
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    • pp.45-52
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    • 2009
  • Generally, structures are analyzed as continuum. However, sometimes it is more efficient to analyze structure as a discrete model rather than as a continuum model in case of the structure has complex shape or loading condition. This study, therefore, suggests an improved analysis discrete model, named Equivalent Truss Model (further as "ETM"), which can obtain similar results with analyzing continuums analysis. ETM adopts a lattice truss to compose the members of the model, and analyses the structures. As a consequence, the ETM produced the identical outcome with the continuums analysis in section force of different structures and loading conditions. Similar results have been shown in internal stress analysis as well. Make use of that ETM is discrete, fractural path of beam was analyzed by ETM and the result was reasonable.

A FINITE-VISCOELASTIC CONTINUUM MODEL FOR RUBBER AND ITS FINITE ELEMENT ANALYSIS

  • Kim, Seung-Jo;Kim, Kyeong-Su;Cho, Jin-Yeon
    • Journal of Theoretical and Applied Mechanics
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    • v.1 no.1
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    • pp.97-109
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    • 1995
  • In this paper, a finite viscoelastic continuum model for rubber and its finite element analysis are presented. This finite viscoelatic model based on continuum mechanics is an extended model of Johnson and Wuigley's 1-D model. In this extended model, continuum based kinematic measures are rigorously defied and by using this kinematic measures, elastic stage law and flow rule are introduced. In kinematics, three configuration are introduced. In kinematics, three configuration are introduced. They are reference, current and virtual visco configurations. In elastic state law, it is assumed that at a certain time, there exists an elastic potential which describes the recoverable elastic energy. From this elastic potential, elastic state law is derived. The proposed flow rule is based on phenomenological observation. The flow rule gives precise relaxation response. In finite element approximation, mixed Lagrangian description is used, where total and similar method of updated Lagrangian descriptions are used together. This approach reduces the numerical job and gives simple nonlinear syatem of equations. To satisfy the incompressible condition, penalty-type modified Mooney-Rivlin energy function is adopted. By this method nearly incompressible condition is obtain the virtual visco configuration. For verification, uniaxial stretch tests are simulated for various stretch rates. The simulated results show good agreement with experiments. As a practical experiments. As a preactical example, pressurized rubber plate is simulated. The result shows finite viscoelastic effects clearly.

Modeling and control of a flexible continuum module actuated by embedded shape memory alloys

  • Hadi, Alireza;Akbari, Hossein
    • Smart Structures and Systems
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    • v.18 no.4
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    • pp.663-682
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    • 2016
  • Continuum manipulators as a kind of mechanical arms are useful tools in special robotic applications. In medical applications, like colonoscopy, a maneuverable thin and flexible manipulator is required. This research is focused on developing a basic module for such an application using shape memory alloys (SMA). In the structure of the module three wires of SMA are uniformly distributed and attached to the circumference of a flexible tube. By activating wires, individually or together, different rotation regimes are provided. SMA model is used based on Brinson work. The SMA model is combined to model of flexible tube to provide a composite model of the module. Simulating the model in Matlab provided a platform to be used to develop controller. Complex and nonlinear behavior of SMA make the control problem hard especially when a few SMA actuators are active simultaneously. In this paper, position control of the two degree of freedom module is under focus. An experimental control strategy is developed to regulate a desired position in the module. The simulation results present a reasonable performance of the controller. Moreover, the results are verified through experiments and show that the continuum module of this paper would be used in real modular manipulators.

A modified replacement beam for analyzing building structures with damping systems

  • Faridani, Hadi Moghadasi;Capsoni, Antonio
    • Structural Engineering and Mechanics
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    • v.58 no.5
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    • pp.905-929
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    • 2016
  • This paper assesses efficiency of the continuum method as the idealized system of building structures. A modified Coupled Two-Beam (CTB) model equipped with classical and non-classical damping has been proposed and solved analytically. In this system, complementary (non-classical) damping models composed of bending and shear mechanisms have been defined. A spatial shear damping model which is non-homogeneously distributed has been adopted in the CTB formulation and used to equivalently model passive dampers, viscous and viscoelastic devices, embedded in building systems. The application of continuum-based models for the dynamic analysis of shear wall systems has been further discussed. A reference example has been numerically analyzed to evaluate the efficiency of the presented CTB, and the optimization problems of the shear damping have been finally ascertained using local and global performance indices. The results reveal the superior performance of non-classical damping models against the classical damping. They show that the critical position of the first modal rotation in the CTB is reliable as the optimum placement of the shear damping. The results also prove the good efficiency of such a continuum model, in addition to its simplicity, for the fast estimation of dynamic responses and damping optimization issues in building systems.

A Study on Discontinuum Analysis and Continuum Analysis of Tunnels in Jointed Rock Mass (절리발달 암반터널의 불연속체해석과 연속체해석에 관한 고찰)

  • Cho Sun-Kyu;Kim Si-Kyeok;Kim Do-Hoon
    • Proceedings of the KSR Conference
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    • 2004.10a
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    • pp.1089-1094
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    • 2004
  • Numerical methods to estimate behaviors of jointed rock mass can be roughly divided into two method : discontinuous model and continuum model. Generally, distinct element method (DEM) is applied in discontinuous model, and finite element method (FEM) or finite difference method (FDM) is utilized in continuum model. To predict a behavior of discontinuous model by DEM, it is essential to understand characteristics of joints developed in rock mass through field tests. However, results of field tests can not provide full information about rock mass because field tests is conducted in limited area. In this paper, discontinuous analysis by UDEC and continuous analysis by FLAC is utilized to estimate a behavior of a tunnel in jointed rock mass. For including discontinuous analysis in continuous analysis, joints in rock mass is considered by reducing rock mass properties obtained by RMR and decreasing shear strength of rock mass. By comparing and revising two analysis results, analysis results similar with practical behavior of a tunnel can be induced and appropriate support system is decided.

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