• Proceedings of the Computational Structural Engineering Institute Conference
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• 1997.04a
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• pp.71-78
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• 1997

The high precision analysis by the p-version of the finite element method are fairly well established as highly efficient method for linear elastic problems, especially in the presence of stress singularity. It has been noted that the merits of p-version are accuracy, modeling simplicity, robustness, and savings in user's and CPU time. However, little has been done to exploit their benefits in elasto-plastic analysis. In this paper, the p-version finite element model is proposed for the materially nonlinear analysis that is based on the incremental theory of plasticity, the associated flow rule, and von-Mises yield criteria. To obtain the solution of nonlinear equation, the Newton-Raphson method and initial stiffness method, etc are used. Several numerical examples are tested with the help of the square plates with cutout, the thick-walled cylinder under internal pressure, and the center cracked plate under tensile loading. Those results are compared with the there cal solutions and the numerical solutions of ADINA software.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.6
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• pp.19-25
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• 2019

We have developed a tool that uses finite element analysis (FEA) to rapidly evaluate a shaft-bearing system of machine tools. We extracted commercial data on suitable clamping units and defined the inner profile of the shaft to avoid needing direct user input to define the profile. We use a splitting algorithm to convert the shaft into beam elements with two diameters and length. To validate the tool, we used it to design and evaluate a shaft-bearing system and found that our tool automated the construction of an FE system model in a commercial FEA package as well as the static stiffness evaluation; both tasks were completed in seconds, demonstrating a significant reduction from the minutes normally required to complete these tasks manually.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.496-504
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• 2011

The region trunk line railroad route undergoes an influence on a large scale in train operation systematic reorganization. This keynote of the train operation not being to the consumer and not to be is because being to the supplier. The trunk line route user of region supply change of the supplier sensitively, accepts but, the demand unit will be able to change the supply massive demanders does not become and like that to accept this back is not the railroad the mean of transportation which grudge is different a mean of transportation mainly makes use. This hits to neither the gist of GLORY promotions of the railroad public corporation which pursues the railroad use which is ordinary even in the basis of governmental policy of stock of coal small green growth and not to be is arranged. For the railroad use activation of the region trunk line route consequently and to excavate the demand hindrance element and a demand lure element the inside and the outside defines and to observe the fluctuation of use importing in existing train operation systematic fluctuation, with the user tries analyzes the instance of the overseas railroad enterprise about the process which reflects the opinion of the area and improvement under preparing boil.

• Transactions of Materials Processing
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• v.9 no.3
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• pp.233-241
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• 2000

It is well known that the quality and efficiency of the design of metal forming processes can be significantly improved with the aid of effective numerical simulations. In the present study, a two-and three-dimensional finite element simulation system, CAMP form, was developed for the analysis of metal forming processes in the PC environment. It is composed of a solver based on the thermo-rigid-viscoplastic approach and graphic user interface (GUI) based pre-and post-processors to be used for the effective description of forming conditions and graphic display of simulation results, respectively. In particular, in the case of CAMPform 2D (two-dimensional), as the solver contains an automatic remeshing module which determines the deformation step when remeshing is required and reconstructs the new mesh system, it is possible to carry out simulations automatically without any user intervention. Also, the forming analysis considers ductile fracture of the workpiece and wear of dies for better usage of the system. In the case of CAMPform 3D, general three-dimensional problems that involve complex die geometries and require remeshing can be analyzed, but full automation of simulations has yet to be achieved. In this paper, the overall structure and computational background of CAMPform will be briefly explained and analysis results of several forming processes will be shown. From the current results, it is construed that CAMPform can be used in providing useful information to assist the design of forming processes.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.1
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• pp.1-7
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• 2015

This paper predicts the spring-in effect of curved laminated composite structure for various stacking sequence using finite element analysis(ABAQUS). In composite manufacturing process, large temperature difference, different coefficient of thermal expansion and chemical shrinkage effect cause distortion of composite parts such as spring-in and warpage. Distortion of composite structure is important issue on quality of product, and it should be considered in manufacturing process. In finite element analysis, a CHILE(Cure Hardening Instantaneously Linear Elastic) model and chemical shrinkage effects are considered developing user subroutine in ABAQUS and some cases are simulated.

• Journal of the Korean GEO-environmental Society
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• v.17 no.12
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• pp.65-72
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• 2016

There are numerous factors that affect stress distribution in a buried pipe, such as the shape, size, and stiffness of the pipe, its burial depth, and the stiffness of the surrounding soil. In addition, the pipe can benefit from the soil arching effect to some extent, through which the overburden and surcharge pressure at the crown can be carried by the adjacent soil. As a result, the buried pipe needs to support only a portion of the load that is not transferred to the adjacent soil. This paper presents numerical efforts to investigate the stress distribution in the buried concrete pipe under various environmental conditions. To that end, a nonlinear elasto-plastic model for backfill materials was implemented into finite element software by a user-defined subroutine (user material, or UMAT) to more precisely analyze the soil behavior surrounding a buried concrete pipe subjected to surface loading. In addition, three different backfill materials with a native soil were selected to examine the material-specific stress distribution in pipe. The environmental conditions considering in this study the loading effect and void effects were investigated using finite element method. The simulation results provide information on how the pressures are redistributed, and how the buried concrete pipe behaves under various environmental conditions.

• Proceedings of the KIEE Conference
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• 1987.11a
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• pp.82-85
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• 1987

The objective of this paper is to develop computer programs to aid in the design and analysis of control systems in which nonlinear characteristics exist. Control systems are dynamic systems, which can be described using various mathematical models. A convenient model for digital computer simulation is the state model in which described using a set of linear and non linear first order differential equations. The digital simulation was performed on a IBM PC/XT personal computer, and the computer language was BASIC. There are four possible configurations from which a user may choose. When running a program, the user is asked to enter the system parameters according to a specified control system configurations are; 1. A control system with a nonlinear element followed by a plant in a feedback configurations(NLSVF1). 2. A control system with a nonlinear device situated between two plants in a feedback configurations(NLSVF2). 3. A control system with a nonlinear element followed by a plant, followed by a the dealy in feedback configurations(TLAG). 4. A motor and load with a backlash nonlinearity between dynamic portions of the motor/load configurations (BACKLASH). The matrix from state equations are integrated using combination the trapezoidal method and fixed point iteration. Several cases which have nonlinearity were implemented on the computer and the results were discussed.

• Science of Emotion and Sensibility
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• v.11 no.3
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• pp.387-396
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• 2008

The paradigm of a product taking a sudden turn of technical development is due to a change of the needs of diversified user, and this shows that users emphasizes on the value of the sensitivity than the standardized form and usableness of the product, and the value of such a sensitivity can relate to the needs of the product, and it can be filled up eventually by the rapid completion of the product. The creativity will be the most important ability in the future society, it is an added value to all the profession workers which people can use that to increase their competitiveness ability. It is recognized the value of the sensitivity represents the feels psychological aspect of the user and it would be the future design trend, by doing this, products designed would be different from the existing products in the market. I am going to show you that this can be used in the design concept derivation process, there is several core design elements in the product development process, these elements can not only represent the basic user needs but also the user inner unconscious needs, at the same time it keeps the aesthetic concern.

• Proceedings of the Korea Contents Association Conference
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• 2006.11a
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• pp.555-559
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• 2006

This paper will intend to contribute to extracting and storing various form of information on user interests by using structural rules user makes and XML-based word document converting techniques. The system named PPE consists of three essential element. One is converting element which converts word documents like HWP, DOC into XML documents, another is extracting element to prepare structural rules and extract concerned information from XML document by structural rules, and the other is storing element to make final XML document or store it into database system. For word document converting, we developed OCX based word converting daemon. Helping user to extracting information, we developed script language having native function/variable processing engine extended from XSLT. This system can be used in the area of constructing word document contents DB or providing various information service based on RAW word documents. We really applied it to project management system and project result management system.

• Journal of the Ergonomics Society of Korea
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• v.23 no.3
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• pp.39-52
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• 2004

Icons are the main element of the graphic user interface (GUI). They can help users perform effectively on the computer, especially when the icons reflect user`s mental model. However, few studies in Korea represented Korean users` mental models in icon design. The purpose of this study, therefore, was to ascertain whether existing icons agreement with Korean twentieth mental model, and to deduce properties of Korean twentieth mental model. To do that, 10 icons from two commercially available toolbar-icons of word processing programs were compared with the newly developed icons, which were developed to represent Korean user`s mental modelthrough interviews, surveys, and mental model sketches. The results show that five new metaphors were found: a dog-eared part on the bottom right corner new for new document, a magnifying glass for search, a red pencil for spell-check, `＋` and `` signs in the magnifying glass for zoom, and a yellow post-it for paste. These new icons were preferred to the existing. Korean twentieth users preferred rather complex and dynamic icons than simple and static ones even though icon development guideline said simple icons are better.