• Title/Summary/Keyword: equilibrium problems

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Tolerance Analysis for Natural Frequencies of Multi-body Systems in Dynamic Equilibrium State (다물체계의 평형위치에서 고유진동수에 대한 공차해석)

  • Eom, Seung-Man;Choi, Dong-Hwan;Yoo, Hong-Hee
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.17 no.1 s.118
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    • pp.65-71
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    • 2007
  • Tolerance analysis method for natural frequencies of multi-body systems having a equilibrium position is suggested in this paper. To perform the tolerance analysis, the Monte-Carlo Method is conventionally employed. However, the Monte-Carlo Method has some weakness; spending too much time for analysis and having a low accuracy and hard to converge in the dynamical unstable area. To resolve these problems, a tolerance analysis method is suggested in this paper. Sensitivity equations of natural frequencies are derived at the equilibrium position. By employing the sensitivity information of mass, damping and stiffness matrices, the sensitivity of natural frequencies can be calculated.

A New Aluminium Container for $\gamma$-Ray Spectrometry Analysis of Radium and Radon (라듐 및 라돈의 감마선 분광 분석을 위한 알루미늄 용기의 제작 및 특성 조사)

  • Lee, Kil Yong;Yoon, Yoon Yeol;Seo, Bum Kyoung
    • Analytical Science and Technology
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    • v.13 no.6
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    • pp.743-750
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    • 2000
  • For the ${\gamma}$-ray spectrometry analysis of radium and radon in environmental samples, plastic Marinelli beakers have been usually used. But, there are two problems; one is the increment of background by adsorption of airborne radon daughters on the plastic beaker, and other is the incompleteness of radioactive equilibrium by the loss of gaseous radon produced during the radioactive equilibrium process. In order to solve these problems, we made aluminium counting container, and investigated its characteristics. We investigated radioactive equilibrium process using the aluminium container. We found that both solid and liquid samples reached at radioactive equilibrium state in the aluminium container without loss of gaseous radon. By the use of the aluminium container, we established radon and radium analysis method of solid and liquid samples using gamma-ray spectrometry.

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A Comparison of the Crack Plane Equilibrium Model for Elastic-Plastic Fracture Analysis with the Irwin's Plastic Zone Corrected LEFM (탄소성 파괴해석을 위한 크랙 평면 평형모형과 항복 선형 파괴역학과의 비교에 관한 연구)

  • Lee, Kyu-Yong;Smith, F.W.
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.20 no.1
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    • pp.30-36
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    • 1984
  • It is well known that the application of linear elastic fracture mechanics is inadequate to solve the large deformation fracture failures which occurr in ductile manner because of the large scale yielding due to the severe stress concentration in the region adjacent to the crack tip. The authors have been evolved a fracture model, the crack plane equilibrium model, for this kinds of elastic-plastic fracture problems in the previous report. In this report, the crack plane equilibrium model was compared with the Irwin's plastic zone corrected linear elastic fracture mechanics through theoretical comparisons and experimental results to examine the validity of the crack plane equilibrium model as an available tool for nonlinear fracture analysis. Through this study, the main results were reached as follows; Irwin's plastic zone corrected linear elastic fracture mechanics could be applicable only for small scale yielding problems as expected while the crack plane equilibrium model valid as a fracture model for large deformation fracture failure. However, the followings should be considered for the more precise evaluations of CPE model; 1) It is necessary to test more specimens which contain small cracks in the range of 2a/W<0.1. 2) It is important to detect the crack initiation point during the fracture test for determining an accurate fracture load. 3) Effects of specimen thickness in the fracture process zone should be examined.

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Algorithmic Properties of Isotone Complementarity Problems

  • Ahn, Byong-Hun
    • Journal of the Korean Operations Research and Management Science Society
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    • v.12 no.1
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    • pp.10-18
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    • 1987
  • This paper discusses algorithmic properties of a class of complementarity programs involving strictly diagonally isotone and off-diagonally isotone functions, i. e., functions whose Jacobian matrices have positive diagonal elements and nonnegative off-diagonal elements, A typical traffic equilibrium under elastic demands is cast into this class. Algorithmic properties of these complementarity problems, when a Jacobi-type iteration is applied, are investigated. It is shown that with a properly chosen starting point the generated sequence are decomposed into two converging monotonic subsequences. This and related will be useful in developing solution procedures for this class of complementarity problems.

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A GENERAL ITERATIVE ALGORITHM COMBINING VISCOSITY METHOD WITH PARALLEL METHOD FOR MIXED EQUILIBRIUM PROBLEMS FOR A FAMILY OF STRICT PSEUDO-CONTRACTIONS

  • Jitpeera, Thanyarat;Inchan, Issara;Kumam, Poom
    • Journal of applied mathematics & informatics
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    • v.29 no.3_4
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    • pp.621-639
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    • 2011
  • The purpose of this paper is to introduce a general iterative process by viscosity approximation method with parallel method to ap-proximate a common element of the set of solutions of a mixed equilibrium problem and of the set of common fixed points of a finite family of $k_i$-strict pseudo-contractions in a Hilbert space. We obtain a strong convergence theorem of the proposed iterative method for a finite family of $k_i$-strict pseudo-contractions to the unique solution of variational inequality which is the optimality condition for a minimization problem under some mild conditions imposed on parameters. The results obtained in this paper improve and extend the corresponding results announced by Liu (2009), Plubtieng-Panpaeng (2007), Takahashi-Takahashi (2007), Peng et al. (2009) and some well-known results in the literature.

A Basic Study on the Establishment of the Consumer Education (소비자교육의 정립을 위한 기초연구)

  • 김순미
    • Journal of the Korean Home Economics Association
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    • v.20 no.4
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    • pp.133-142
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    • 1982
  • The Consumer Education is one of the rapidly raised problems in the process of recent Economic Growth. As the Society and its economy changes into Oligopoly, the nature and the scope of the Consumer Education also changes. However, We don't have an institutional, systematic education of consumers. Even the basic concepts of Consumer Education has not yet been established, because it is in an infant state. Thus, the aim of this paper is to establish the fundermental concepts of Consumer Education and to help settlement of the direction of Consumer Education. The conclusions are as following: First, Consumers as the objects of Consumer Education are limited to the Ultimate-Consumer; and they can divided into three groups-Individual Consumer, Consumer-Group, the Consuming Masses. Now were have to deal with not only the concept of Ultimate Consumer which limited to the Consumer, but deal with the realistic problems involving Citizens and Livers. Second, Consumer Education is systematic educational activity in order that Consumers can assume an subjective behavior for the purpose of improvement and support of their own rights in society. Third, Consumer Education which enforced Consumers' Cooperative Society and Goods Test is the movements of systematic resistance of consumers. The former aims at Economic Equilibrium, while the latter Informative Equilibrium. so, the two movements should channel the direction of Consumer Education in order to realize the Equilibrium.

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Bilinear plate bending element for thin and moderately thick plates using Integrated Force Method

  • Dhananjaya, H.R.;Nagabhushanam, J.;Pandey, P.C.
    • Structural Engineering and Mechanics
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    • v.26 no.1
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    • pp.43-68
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    • 2007
  • Using the Mindlin-Reissner plate theory, many quadrilateral plate bending elements have been developed so far to analyze thin and moderately thick plate problems via displacement based finite element method. Here new formulation has been made to analyze thin and moderately thick plate problems using force based finite element method called Integrated Force Method (IFM). The IFM is a novel matrix formulation developed in recent years for analyzing civil, mechanical and aerospace engineering structures. In this method all independent/internal forces are treated as unknown variables which are calculated by simultaneously imposing equations of equilibrium and compatibility conditions. In this paper the force based new bilinear quadrilateral plate bending element (MQP4) is proposed to analyze the thin and moderately thick plate bending problems using Integrated Force Method. The Mindlin-Reissner plate theory has been used in the formulation of this element which accounts the effect of shear deformation. Standard plate bending benchmark problems are analyzed using the proposed element MQP4 via Integrated Force Method to study its performance with respect to accuracy and convergence, and results are compared with those of displacement based 4-node quadrilateral plate bending finite elements available in the literature. The results are also compared with the exact solutions. The proposed element MQP4 is free from shear locking and works satisfactorily in both thin and moderately thick plate bending situations.

Some explicit solutions to plane equilibrium problem for no-tension bodies

  • Lucchesi, Massimiliano;Zani, Nicola
    • Structural Engineering and Mechanics
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    • v.16 no.3
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    • pp.295-316
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    • 2003
  • A method is presented to integrate explicitly certain equilibrium problems for no-tension bodies, in absence of body forces and under the assumption that two of the principal stresses are everywhere null. The method is exemplified in the case of rectangular panels, clamped at their bottoms and loaded at their tops.

Solids 3-D with bounded tensile strength under the action of thermal strains. Theoretical aspects and numerical procedures

  • Pimpinelli, Giovanni
    • Structural Engineering and Mechanics
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    • v.18 no.1
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    • pp.59-78
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    • 2004
  • This paper is devoted to illustrate some numerical procedures to solve the boundary equilibrium problems of three-dimensional solids that are subjected to thermal strains. The constitutive equations take into account the bounded tensile strength of the material and they are presented in the framework of non-linear elasticity and small strains. The associated equilibrium problem is solved numerically by means of the finite element method and the numerical techniques, i.e. the Newton-Raphson method and the secant method, are revised in order to assure the solution convergence of the discretized problem. Some numerical examples are illustrated.

NEW MAXIMUM THEOREMS WITH STRICT QUASI-CONCAVITY

  • Kim, Won-Kyu;Yoon, Ju-Han
    • Bulletin of the Korean Mathematical Society
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    • v.38 no.3
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    • pp.565-573
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    • 2001
  • In this paper, we first rove the strict quasi-concavity of maximizing function, and next prove a new maximum theorem using Fan’s generalization of the classical KKM theorem. Also an existence theorem of social equilibrium can be proved when an additional assumption on the constraint correspondence is assumed. Finally, we give illustrative two examples of constrained optimization problems.

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