• Title/Summary/Keyword: geometric compatibility

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A Study on the Aggregation of Multi-Experts Priorities Using Compatibility in the AHP (Compatibility를 이용한 다수 전문가의 가중치 종합화에 관한 연구)

  • 조성훈;김태성;이영찬
    • Journal of the Korean Operations Research and Management Science Society
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    • v.23 no.4
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    • pp.131-140
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    • 1998
  • The objective of this study is to propose a new procedure to synthesize the multi-experts priorities in AHP. If multi-experts with different expertise are involved in a AHP decision, we need some way to aggregate their opinions. AHP model used to do numerical aggregation by taking only the geometric mean or the weighting geometric mean in past. To aggregate the multi-experts priorities, In this paper. we suggest a way which Decision Maker can exclude outlier matrix from group using the concept of the Compatibility and we Introduce Delphi method to use Compatibility in AHP. A numerical example is shown to illustrate the procedure.

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Three Dimensional Visualization of Contact Region for a Protein Complex (단백질 복합체를 위한 접촉 영역의 3차원 가시화)

  • Kang, Beom Sik;Kim, Ku-Jin;Kim, Yukyeong
    • KIPS Transactions on Software and Data Engineering
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    • v.2 no.12
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    • pp.899-902
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    • 2013
  • In this paper, we present a method to visualize the contact region between two molecules in a protein complex in a threedimensional space. The contact region of two molecules shows compatibility in geometric aspects. Usually, the computation of the area of contact region has been used to show the strength of compatibility. The numerical value and simple drawing of contact region would be useful for comparing the relative strength of different contacts, but it is not appropriate for analysing the geometric characteristics of the contact region. In this paper, we present a method to show the compatibility between two molecules by visualizing the distance information between them.

Blank Design and Strain Prediction in Sheete Metal Forming Process (박판금속 성형공정에서의 블랭크 설계및 변형률 예측)

  • Lee, Choong-Ho;Huh, Hoon
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.20 no.6
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    • pp.1810-1818
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    • 1996
  • A new finite elemetn approach is introduced for direct prediction of bland shapes and strain distributions from desired final shapes in sheet metal forming. The approach deals with the geometric compatibility of finite elements, plastic deformation theory, minimization of plastic work with constraints, and a proper initial guess. The algorithm developed is applied to cylindrical cup drawing, square cup drawing, and fron fender forming to confirm its validity by demonstratin reasonable accurate numerical results of each problems. Rapid calculation with this algorithm enables easy determination of various process variables for design of sheet metal forming process.

Transient Response Analysis of Locally Nonlinear Structures Using Substructure-Based-State Equations (부분구조의 상태방정식을 이용한 국부 비선형계의 과도응답해석)

  • 김형근;박윤식
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.17 no.10
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    • pp.2457-2466
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    • 1993
  • A simple method is presented for determining transient responses of locally nonlinear structures using substructure eigenproperties and Lagrange multiplier technique. Although the method is based upon the mode synthesis formulation procedure, the equations of the combined whole structure are not constructed compared with the conventional methods. Lagrange multi-pliers are used to enforce the conditions of geometric compatibility between the substructure interfaces and they are treated as external forces on each substructure itself. Substructure eigenvalue problem is defined with the substructure interface free of fixed. The transient analysis is based upon the recurrence discrete-time state equations and offers the simplicity of the Euler integration method without requiring small time increment and iterative solution procedure. Numerical examples reveal that the method is very accurated and efficient in calculating transient responses compared with the direct numerical integration method.

A Compatibility Study on Blank Support Structure for Large and Curved Thick Plate Forming (대곡면 후곡판 성형을 위한 블랭크 지지구조의 적합성 연구)

  • Lim, M.R.;Kwak, B.S.;Kang, B.S.;Ku, T.W.
    • Transactions of Materials Processing
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    • v.28 no.6
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    • pp.335-346
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    • 2019
  • Thick plate forming is presented to manufacture a large and curved member of steam turbine diaphragm. Due to three-dimensional asymmetry of target geometry, it is hard to consistently keep the blank position in die cavity between forming punch and die. In order to relieve the position instability of the blank during the thick plate forming, a blank support structure is proposed to be composed of guide pins and linear bearing, and blank guide arm enlarged from both longitudinal ends of the thick blank. In this study, parametric investigations with regard to the geometric position and width of the blank guide arm are carried out. As main geometric parameters, 2 positions such as maximum curvature region and minimum one on a curved cross-section profile of the target shape are selected, and 14 widths of the blank guide arm are considered. Using 28 variable combinations, three-dimensional numerical simulations are performed to predict the appropriate range of the process parameters. The compatibility and validity of the blank support structure with the blank guide arm for the thick plate forming is verified through the thick plate forming experiments.

Structural Modal Analysis Using Substructure Hybrid Interface Modes (혼합경계의 부분구조 모드를 이용한 구조물의 모드해석)

  • 김형근;박윤식
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.17 no.5
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    • pp.1138-1149
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    • 1993
  • A new mode synthesis method using Lagrange multipliers and substructure hybrid interface modes is presented. Substruture governing equations of motion are derived using Lagrange equations and the constraints of geometric compatibility between the substructures are treated with Lagrange multipliers. Fixed, free, and loaded interface modes can be employed for the modal bases of each substructure. In cases of the fixed and loaded interface modes, two successive modal transformation relations are used. Compared with the conventional mode synthesis methods, the suggested method does not construct the equations of motion of the coupled structure and the final characteristic equation becomes a polynomial. Only modal parameters of each substructure and geometric compatibility conditions are needed. The suggested method is applied to a simple lumped mass model and parametric study is performed.

Compatibility Analysis of Wheel/Rail Profile on Conventional Railway (기존철도 차륜/레일형상의 적합성 분석)

  • Hur, Hyun-Moo;Seo, Jung-Won;Chung, Heung-Chai;Goo, Dong-Hoe
    • Proceedings of the KSME Conference
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    • 2004.04a
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    • pp.934-939
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    • 2004
  • Railway wheel/rail contact conditions have an influence on dynamic behavior of rolling stock. If there are problems of incompatibility between wheel and rail, damages like wheel wear, wheel spalling, rail wear, etc are occurred. Especially wheel and rail profiles are important factor of vehicle curving performance, so compatibility study between wheel and rail has to be carried out preferentially, In this study, we have analyzed the compatibility between wheel and rail of KNR conventional line to improve the maintenance efficiency of wheel and rail. Thus we showed the results relating to wheel/rail geometric contact, vehicle running performances as the change of wheel/rail combination.

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An Iterative Method to Determine Deformed Shape of Cable (케이블 처짐 형상 결정을 위한 반복 계산법의 개발)

  • 정진환;조현영;박용명;계만수
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.15 no.4
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    • pp.715-725
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    • 2002
  • In this study, a method to determine the deformed shape of planar cable under vertical loads was presented. To obtain the deformed shape of cable by general cable theorem, a sag at arbitrary point is usually given. However, in general cases without a given sag, the proposed method determines the deformed shape of cable based on the equations of cable theorem and geometric compatibility by iterative way. The method was also extended to slove extensible cable. It was acknowledged from numerical analysis and model tests in laboratory that the proposed method is valid lot analysis of extensible cable as well as unextensible cable.

A GEOMETRIC APPROACH TO TIMELIKE FLOWS IN TERMS OF ANHOLONOMIC COORDINATES

  • Yavuz, Ayse;Erdogdu, Melek
    • Honam Mathematical Journal
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    • v.44 no.2
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    • pp.259-270
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    • 2022
  • This paper is devoted to the geometry of vector fields and timelike flows in terms of anholonomic coordinates in three dimensional Lorentzian space. We discuss eight parameters which are related by three partial differential equations. Then, it is seen that the curl of tangent vector field does not include any component in the direction of principal normal vector field. This implies the existence of a surface which contains both s - lines and b - lines. Moreover, we examine a normal congruence of timelike surfaces containing the s - lines and b - lines. Considering the compatibility conditions, we obtain the Gauss-Mainardi-Codazzi equations for this normal congruence of timelike surfaces in the case of the abnormality of normal vector field is zero. Intrinsic geometric properties of these normal congruence of timelike surfaces are obtained. We have dealt with important results on these geometric properties.

A Study on Dynamic Characteristics of the Rolling-stock for the Combination of Domestic Wheel/Rail Profiles (국내 철도 차륜/레일형상 조합에 따른 차량 동특성 분석 연구)

  • Hur Hyun-Moo;Seo Jung-Won;Kwon Seok-Jin;Kim Nam-Po
    • Journal of the Korean Society for Railway
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    • v.8 no.5
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    • pp.483-489
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    • 2005
  • Railway wheel/rail contact conditions have influences on dynamic behavior of the rolling stock. If there are incompatibility problems between the wheel and rail, damages like wheel wear, wheel spalling, rail wear, etc are occurred. Especially wheel and rail profiles are important factors of vehicle curving performance, so compatibility studies between wheel and rail profiles have to be carried out preferentially. In this study, we have studied the compatibility between wheel and rail profiles of KNR conventional line to analyze the dynamic performances of the rolling-stock. Thus we showed the results relating to wheel/rail geometric contact, vehicle running performances as the change of wheel/rail combination.