• Title/Summary/Keyword: boundary method

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New IEEE 1149.1 Boundary Scan Architecture for Multi-drop Multi-board System (멀티 드롭 멀티 보드 시스템을 위한 새로운 IEEE 1149.1 경계 주사 구조)

  • Bae, Sang-Min;Song, Dong-Sup;Kang, Sung-Ho;Park, Young-Ho
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.49 no.11
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    • pp.637-642
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    • 2000
  • IEEE 1149.1 boundary scan architecture is used as a standard in board-level system testing. The simplicity of this architecture is an advantage in system testing, but at the same time, it it makes a limitation of applications. Because of several problems such as 3-state net conflicts, or ambiguity issues, interconnect testing for multi-drop multi-board systems is more difficult than that of single board systems. A new approach using IEEE 1149.1 boundary scan architecture for multi-drop multi-board systems is developed in this paper. Adding boundary scan cells on backplane bus lines, each board has a complete scan-chain for interconnect test. This new scan-path insertion method on backplane bus using limited 1149.1 test bus less area overhead and mord efficient than previous approaches.

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Nonlinear snap-buckling and resonance of FG-GPLRC curved beams with different boundary conditions

  • Lei-Lei Gan;Gui-Lin She
    • Geomechanics and Engineering
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    • v.32 no.5
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    • pp.541-551
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    • 2023
  • Snap-buckling is one of the main failure modes of structures, because it will lead to the reduction of structural bearing capacity, durability loss and even structural damage. Boundary condition plays an important role in the research of engineering mechanics. Further discussion on the boundary conditions problems will help to analyze the dynamic and static behavior of structures more accurately. Therefore, in order to understand the dynamic and static behavior of curved beams more comprehensively, this paper mainly studies the nonlinear snap-through buckling and forced vibration characteristics of functionally graded graphene reinforced composites (FG-GPLRCs) curved beams with two different boundary conditions (including clamped-hinged and hinged-hinged) using Euler-Bernoulli beam theory (E-BBT). In addition, the effects of the curved beam radius, the GLPs distributions, number of GLPs layers, the mass fraction of GLPs and elastic foundation parameters on the nonlinear snap-through buckling and forced vibration behavior are discussed respectively.

Active Contour Model for Boundary Detection of Multiple Objects (복수 객체의 윤곽 검출 방법에 대한 능동윤곽모델)

  • Jang, Jong-Whan
    • The KIPS Transactions:PartB
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    • v.17B no.5
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    • pp.375-380
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    • 2010
  • Most of previous algorithms of object boundary extraction have been studied for extracting the boundary of single object. However, multiple objects are much common in the real image. The proposed algorithm of extracting the boundary of each of multiple objects has two steps. In the first step, we propose the fast method using the outer and inner products; the initial contour including multiple objects is split and connected and each of new contours includes only one object. In the second step, an improved active contour model is studied to extract the boundary of each object included each of contours. Experimental results with various test images have shown that our algorithm produces much better results than the previous algorithms.

Analysis of Multi-Layered Structural Systems Using Nonlinear Finite Elements-Boundary Elements (반무한 다중 구조계의 비선형 유한요소 - 경계요소 해석)

  • 김문겸;장정범;이상도;황학주
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1992.04a
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    • pp.58-64
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    • 1992
  • It is usual that underground structures are constructed within multi-layered medium. In this paper, an efficient numerical model ling of multi-layered structural systems is studied using coupled analysis of finite elements and boundary elements. The finite elements are applied to the area in which the material nonlinearity is dominated, and the boundary elements are applied to the far field area where the nonlinearity is relatively weak. In the boundary element model 1 ins of the multi-layered medium, fundamental solutions are restricted. Thus, methods which can utilize existing Kelvin and Melan solution are sought for the interior multi-layered domain problem and semi infinite domain problem. Interior domain problem which has piecewise homogeneous layers is analyzed using boundary elements with Kelvin solution; by discretizing each homogeneous subregion and applying compatibility and equilibrium conditions between interfaces. Semi-infinite domain problem is analyzed using boundary elements with Melan solution, by superposing unit stiffness matrices which are obtained for each layer by enemy method. Each methodology is verified by comparing its results which the results from the finite element analysis and it is concluded that coupled analysis using boundary elements and finite elements can be reasonable and efficient if the superposition technique is applied for the multi-layered semi-infinite domain problems.

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Robust Controller with Adaptation within the Boundary Layer Application to Nuclear Underwater Inspection Robot

  • Park, Gee-Yong;Yoon, Ji-Sup;Hong, Dong-Hee;Jeong, Jae-Hoo
    • Nuclear Engineering and Technology
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    • v.34 no.6
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    • pp.553-565
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    • 2002
  • In this paper, the robust control scheme with the improved control performance within the boundary layer is proposed. In the control scheme, the robust controller based on the traditional variable structure control method is modified to have the adaptation within the boundary layer. From this controller, the width of the boundary layer where the robust control input is smoothened out can be given by an appropriate value. But the improved control performance within the boundary layer can be achieved without the so-called control chattering because the role of adaptive control is to compensate for the uncovered portions of the robust control occurred from the continuous approximation within the boundary layer Simulation tests for circular navigation of an underwater wall-ranging robot developed for inspection of wall surfaces in the research reactor, TRIGA MARK III, confirm the performance improvement. Notational Conventions Vectors are written in boldface roman lower-case letters, e.g., x and y. Matrices are written in upper-case roman letters, e.g., G and B. And ∥.∥ means the Euclidean norm.

Boundary Detection of 3D MR Images (3차원 자기공명영상의 외부윤곽검출)

  • Choe, U-Yeong;Hwang, Yong-Ho
    • Journal of Biomedical Engineering Research
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    • v.20 no.1
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    • pp.69-73
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    • 1999
  • In this paper, an algorithm based on Snakes is proposed to detect the boundary of 3D images. From the first-slice MR image, the boundary of an object is detected manually. The detected boundary points are used as initial control points for detecting the boundary of the next MR image. To detect the boundary from the rest of MR images automatically, an energy term using spatial correlation between adjacent images is added to the Greedy Snakes energy formulation. A measure of shape similarity called BMD was used to evaluate the accuracy of the proposed algorithm. The average BMD value for the proposed algorithm's result is higher than Greedy algorithm's showing the utility of the proposed method.

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A Comparison of the Algorithm between Korea and Japan in Maritime Boundary Delimitation (해양경계획선 알고리즘에 관한 연구)

  • Kim Byung-Guk;Jin Hai-Ming;Kim Hyung-Su
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.23 no.2
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    • pp.211-217
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    • 2005
  • The general rule of boundary delimitation is the principle of equidistance. The principle of equidistance is a method that determine boundary delimitation from the fixed distant of baseline or basepoint. But there is no artificial and natural object in the sea to determine boundary. And the principle of equidistant can't be applied in every cases, because of the local characteristic of ground. In this paper, we suggest Three-Point Algorithm which is effective algorithm for maritime boundary delimitation. And the main objective of this study is to get capability of maritime boundary delimitation technique.

A Study of Accuracy Improvement of an Analysis of Flow around Arbitrary Bodies by Using an Eulerian-Lagrangian Method (Eulerian-Lagrangian 방법을 사용한 임의 물체주위 유동해석의 정도 향상을 위한 연구)

  • Park I. R.;Chun H. H.
    • Journal of computational fluids engineering
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    • v.6 no.3
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    • pp.19-26
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    • 2001
  • An Eulerian-Lagrangian method, so called immersed boundary method, is used for analysing viscous flow around arbitrary bodies, where governing equations are discretized on a regular grid by using a finite volume method. To improve the accuracy of flow near body boundaries, a second-order accurate interpolation scheme is used and a level-set based grid deformation method is presented to construct the adaptive grids around body boundaries. The present scheme is used to simulate steady flow around a semicircular cylinder mounted on the bottom of flow domain and calculated results are validated by results of a body fitted grid method. Finally, present method is applied to a complex flow around multi body and the usefulness is checked by investigating calculated results.

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A variationally coupled Element-Free Galerkin Method(EFGM) -Boundary Element Method(BEM) (무요소법과 경계요소법의 변분적 조합)

  • 이상호;김명원
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2001.10a
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    • pp.11-18
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    • 2001
  • In this paper, a new algorithm of coupling Element-Free Galerkin Method(EFGM) and Boundary Element Method(BEM) using the variational formulation is presented. A global variational coupling formulation of EFGM-BEM is achieved by combining the variational form on each subregion. In the formulation, Lagrange multiplier method is introduced to satisfy the compatibility conditions between EFGM subregion and BEM subregion. Some numerical examples are studied to verify accuracy and efficiency of the proposed method, in which numerical performance of the method is compared with that of conventional method such as EFGM-BEM direct coupling method, EFGM and BEM. The proposed method incorporating the merits of EFGM and BEM is expected to be applied to special engineering problems such as the crack propogation problems in very large domain, and underground structures with joints.

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A FINITE DIFFERENCE APPROXIMATION OF A SINGULAR BOUNDARY VALUE PROBLEM

  • Lee, H.Y.;Ohm, M.R.;Shin, J.Y.
    • Bulletin of the Korean Mathematical Society
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    • v.35 no.3
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    • pp.473-484
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    • 1998
  • We consider a finite difference approximation to a singular boundary value problem arising in the study of a nonlinear circular membrane under normal pressure. It is proved that the rate of convergence is $O(h^2)$. To obtain the solution of the finite difference equation, an iterative scheme converging monotonically to the solution of the finite difference equation is introduced. And the numerical experiment of this method is given.

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