• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.10a
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• pp.229-234
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• 1994

The major objective of the present paper is to estabilish finite element simulation technique in order to further analyze the shearing process. For this the ductile fracture criterion and element kill method are used in the present work. It is postulated that a fracture initiation is based on the magnitude of local effective strain. The features of sheared surface are easily observed by the element kill method. The simulation results are compard with existing experimental results. It is found that the results of the present work are close agreement with the existing results.

• Journal of the Korean housing association
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• v.25 no.3
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• pp.131-143
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• 2014

The purpose of this study is to develop an operation manual of resident-driven community program by evaluating community program operation to realize a sustainable apartment complex and vitalize a community. To achieve this purpose, 8 community experts, who are in charge of 42 complexes of 7 autonomous districts among 25 districts in Seoul were interviewed from September 2013 to December 2013. Main results of the study are as follows. 1) Operational problems and improvements are deduced from evaluating operation process of community programs. It is found that smooth cooperation of main operators including a community vitalization association, a resident representative meeting and a control office is the most important. 2) Operation guideline for representative programs are suggested based on analysis of operational characteristics of 3 types of community programs; communication, recycling and environment management, according to program operation elements; material element, programming element, human element and finance element. 3) An operation manual of resident-oriented community program is presented after considering evaluation of operation processes and analysis of 3 types of operational elements of community programs.

• Geomechanics and Engineering
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• v.1 no.2
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• pp.121-142
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• 2009

The paper deals with the applications of spectral finite element method to the dynamic analysis of framed foundations supporting high speed machines. Comparative performance of approximate dynamic stiffness methods formulated using static stiffness and lumped or consistent or average mass matrices with the exact spectral finite element for a three dimensional Euler-Bernoulli beam element is presented. The convergence of response computed using mode superposition method with the appropriate dynamic stiffness method as the number of modes increase is illustrated. Frequency proportional discretisation level required for mode superposition and approximate dynamic stiffness methods is outlined. It is reiterated that the results of exact dynamic stiffness method are invariant with reference to the discretisation level. The Eigen-frequencies of the system are evaluated using William-Wittrick algorithm and Sturm number generation in the $LDL^T$ decomposition of the real part of the dynamic stiffness matrix, as they cannot be explicitly evaluated. Major's method for dynamic analysis of machine supporting structures is modified and the plane frames are replaced with springs of exact dynamic stiffness and dynamically flexible longitudinal frames. Results of the analysis are compared with exact values. The possible simplifications that could be introduced for a typical machine induced excitation on a framed structure are illustrated and the developed program is modified to account for dynamic constraint equations with a master slave degree of freedom (DOF) option.

• Structural Engineering and Mechanics
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• v.4 no.3
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• pp.209-226
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• 1996

One of the major divisions in the mathematical modelling of a tubular structure is to include the effect of the transverse shear stress and rotary inertia in vibration of members. During the past three decades, problems of vibration of tubular structures have been considered by some authors, and special attention has been devoted to the Timoshenko theory. There have been considerable efforts, also, to apply the method of spectral analysis to vibration of a structure with rectangular section beams. The purpose of this paper is to compare the results of the spectrally formulated finite element analyses for the Timoshenko theory with those derived from the conventional finite element method for a tubular structure. The spectrally formulated finite element starts at the same starting point as the conventional finite element formulation. However, it works in the frequency domain. Using a computer program, the proposed formulation has been extended to derive the dynamic response of a tubular structure under an impact load.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.10 no.3
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• pp.1-6
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• 2011

This study focused on the localization of swivel type tube couplers, which all depend on imports. In this study, a computer application analysis was performed using a finite element method as a preliminary study. In the major developments related to the objective of this study, the air brake system produced by car makers represents a different in the installation point of an air tank according to the type of cars or in the length and direction of its hoses and that leads to cause lots of problems. For solving such problems, the design of the major elements in a swivel type tube coupler was analyzed using a finite element method, and its validity was also verified. In the process that verifies the validity of this study, it was necessary to investigate how much external force affects the desorption of the tube support, which is the most important element in swivel type tube couplers. For achieving the investigation, a pressure test was implemented for the tube support according to the Federal Motor Vehicle Safety Standards(FMVSS). In the results of the pressure test, all samples satisfied the FMVSS. In addition, several tests were implemented by installing the sample of the developed swivel type tube coupler to an actual vehicle. In particular, rotation tests with various angles were applied by welding the swivel type coupler to an air tank through an argon welding process. In the results of the installing test for an actual vehicle, it was verified that the designed structure was determined as a structure that is able to endure the eccentric torque and deformation pressure applied to several directions that are the major problems in such fixed type tube couplers. Therefore, in the comparison of the performance of the developed product with the product of PARKER, it was possible to verify that the localized swivel type tube coupler developed in this study shows more excellent than that of the existing products by PARKER.

• The Journal of the Korea Contents Association
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• v.11 no.12
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• pp.475-485
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• 2011

The purpose of this study is to find intervention strategies of university and social welfare agency through analysis of factors influencing on field education outcomes and professional identity of social welfare in cyber university and ordinary university students. The major findings are as follows. First, the degree of field education outcome in cyber university students is higher than ordinary university ones. Second, supervision and university element are meaningful factors to constituent variables of field education outcomes in participants, but major satisfaction is only important for ordinary university students. Third, professional identity is related to major satisfaction, supervision, and university element in cyber university students. But university element hasn't influence on professional identity in ordinary university students. Therefore, supervisors have to give systematic instruction and do clear role model. Universities make an effort to improve major satisfaction and the quality as a pre-social worker.

• The Journal of the Petrological Society of Korea
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• v.3 no.2
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• pp.109-127
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• 1994

We report field relationship, petrography and major and trace element chemistry for the central part of the Seoul granitic bathlith of Jurassic age occurring in the Kyonggi massif. The batholith consists mainly of biotite granite (BG) and garnet biotite granite (GBG) with minor tonalite-quartz diorite and biotite granodiorite with or without hornblende. The mode data, along with the those reported by Hong (1984) for the biotite granite (south-BG) in the southern part of the batholith, indicate that the many of BGs and majority of GBG and south-BG are leucocratic. Major element data indicate that these predominant rocks of the batholith are peraluminous. Variation trends in Harker diagrams for the major and trace elements suggest that the BG and GBG are not related by a simple crystal fractionation process. The same is true between the central (BG and GBG) and the southern (south-BG) parts of the batholith, suggesting that the central and southern parts of the Seoul batholith may consist of three separate intrusions. Tectonic discriminations using major and trace element data and the age of emplacement suggest that the batholith represents Jurassic plutonism related to an orogeny, perhaps to a subduction-related continental magmatic arc.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2006.04a
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• pp.567-574
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• 2006

We present applications of MLS-based finite elements, which enable us to easily treat highly complex nonmatching finite element meshes and discontinuities. The shape functions of MLS-based finite element can be easily generated with the aid of Moving Least Square approximation on the parental domain. The major advantage includes that the position of element nodes as well as the number of the element nodes can be conveniently adjusted according to the nature of the problems under consideration, so that finite-element mesh is straightforwardly adapted to evolving discontinuities and. interfaces. Furthermore, we show that the present MLS-based finite elements are efficiently applied for elastic-plastic deformations, wherein the implicit constraint of incompressibility should be properly handled.

• Transactions of Materials Processing
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• v.9 no.2
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• pp.128-139
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• 2000

Wrinkling is one of the major defects in sheet metal products and may be also attributable to the wear of the tool. The initiation and growth of wrinkles are influenced by many factors such as stress state, mechanical properties of the sheet material, geometry of the body, and contact condition. It is difficult to analyze the wrinkling initiation and growth considering the factors because the effects of the factors are very complex and the wrinkling behavior may show a wide variation for small deviations of the factors. In this study, the bifurcation theory is introduced for the finite element analysis of wrinkling initiation and growth. All the above mentioned factors are conveniently considered by the finite element method. The finite element formulation is based on the incremental deformation theory and elastic-plastic elements considering the planar anisotropy of the sheet metal. The proposed method is verified by employing a column buckling problem. And then, the initiation and growth of wrinkling in deep drawing of cylindrical cup are analyzed.

• Journal of Families and Better Life
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• v.26 no.4
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• pp.149-162
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• 2008

The purpose of this study is to provide a meaningful thought to professionals and administrators of Korea working for Consumer General Education development at their Universities. Also, tips for organizing and meaning Consumer General Education Curriculum effectively are provided. Finally, the study suggests essential elements to improve qualities of Consumer General Education in Korea Universities. This study's method are content analysis through web site and survey. The subjects of this survey were 257 students. The data were collected by qusetionaires developed by researcher and analyzed by frequencies, correlation Analysis, One Way Anova, Duncan Test, Factor Analysis, Multiple Regression Analysis. The major findings were as follows: University students's satisfaction level about General Education was low and the needs level about Consumer General Education was high. And the education service quality showed factors to be administrative service element, professor service element, classroom environment element, communication element. And Multiple Regression Analysis on each of the education service quality factors had been significant effects for find out the differences in the degree of satisfaction.