• Journal of the Earthquake Engineering Society of Korea
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• v.19 no.1
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• pp.37-43
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• 2015

This paper presents a detailed procedure for a nonlinear soil-structure interaction of a seismically isolated NPP(Nuclear Power Plant) structure using the boundary reaction method (BRM). The BRM offers a two-step method as follows: (1) the calculation of boundary reaction forces in the frequency domain on an interface of linear and nonlinear regions, (2) solving the wave radiation problem subjected to the boundary reaction forces in the time domain. For the purpose of calculating the boundary reaction forces at the base of the isolator, the KIESSI-3D program is employed in this study to solve soil-foundation interaction problem subjected to vertically incident seismic waves. Wave radiation analysis is also employed, in which the nonlinear structure and the linear soil region are modeled by finite elements and energy absorbing elements on the outer model boundary using a general purpose nonlinear FE program. In this study, the MIDAS/Civil program is employed for modeling the wave radiation problem. In order to absorb the outgoing elastic waves to the unbounded soil region, spring and viscous-damper elements are used at the outer FE boundary. The BRM technique utilizing KIESSI-3D and MIDAS/Civil programs is verified using a linear soil-structure analysis problem. Finally the method is applied to nonlinear seismic analysis of a base-isolated NPP structure. The results show that BRM can effectively be applied to nonlinear soil-structure interaction problems.

• Education of Primary School Mathematics
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• v.7 no.1
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• pp.43-56
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• 2003

In late 19C, German mathematician Felix Klein declaired "Erlangen program" to reform mathematics education in Germany. The main ideas of "Erlangen program" contain the importance of instructing the concepts of functions and groups in school mathematics. After one century from that time, the importance of concepts of groups revived by Bourbaki in the sense of the algebraic structure which is the most important structure among three structures of mathematics - algebraic structure. ordered structure and topological structure. Since then, many mathematicians and mathematics educators devoted to work with the concepts of group for school mathematics. This movement landed on Korea in 21C, and now, the concepts of groups appeared in element mathematics text as plane rigid motion. In this paper, we state the rigid motions centered the symmetry - an important notion in group theory, then summarize the results obtained from some classroom activities. After that, we discuss the responses of children to concepts of groups.of groups.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2005.11a
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• pp.111-114
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• 2005

This paper presents a comparison of experimental value by hemispherical grounding simulation system and calculated value by CDEGS program for ground potential rise of structure. When a test current flowed through structure grounding electrodes, ground potential rise was measured and analyzed for types of structure using the hemispherical grounding simulation system in real time, and was computed by means of CDEGS program. The model structures were designed and fabricated with two types on a scale of one-one hundred sixty. When the experimental data were compared with the theoretical values, the similar profile was shown. Therefore, the confidence of measurement was obtained. The distributions of ground surface potential are dependent on the resistivity and absorption percentage in concrete attached to structure.

• ETRI Journal
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• v.5 no.3
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• pp.16-25
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• 1983

Increasing importance is being attached to the idea of measuring software characteristics. This paper deals with following things. First, a relation of program and flow graph is discussed. It describes a theoretic complexity measure and illustrates how it can be used to manage and control program complexity. Second, cyclomatic complexity measure is discussed. The complexity is independent of physical size and depends only on the decision structure of a program. Third, consider a knot which defines crossing point and provide the ordering of the nodes to make the transition from a two dimensional graph to a one dimensional program. A program modules that can improve FORTRAN IV program text is tested by knot counting and its control complexity is improved.

• International Journal of Naval Architecture and Ocean Engineering
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• v.11 no.1
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• pp.572-583
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• 2019

This paper aims to assess the applicability of the Runge Kutta Discontinuous Galerkin-Direct Ghost Fluid Method to the internal explosion inside a water-filled tube, which previously was studied by many researchers in separate works. Once the explosive charge located at the inner center of the water-filled tube explodes, the tube wall is subjected to an extremely high intensity fluid loading and deformed. The deformation causes a modification of the field of fluid flow in the region near the water-structure interface so that has substantial influence on the response of the structure. To connect the structure and the fluid, valid data exchanges along the interface are essential. Classical fluid structure interaction simulations usually employ a matched meshing scheme which discretizes the fluid and structure domains using a single mesh density. The computational cost of fluid structure interaction simulations is usually governed by the structure because the size of time step may be determined by the density of structure mesh. The finer mesh density, the better solution, but more expensive computational cost. To reduce such computational cost, a non-matched meshing scheme which allows for different mesh densities is employed. The coupled numerical approach of this paper has fewer difficulties in the implementation and computation, compared to gas dynamics based approach which requires complicated analytical manipulations. It can also be applied to wider compressible, inviscid fluid flow analyses often found in underwater explosion events.

• Korean journal of communication and information
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• v.71
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• pp.194-223
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• 2015

This study explores a value chain structure of TV program including news, drama, and comedy. The purpose of this research focused on factor analysis and the relationship among viewer's program selection motivations. This research explores correlation between personal value and viewing motivation. This study was to identify the value structure of respondent on TV program(news, drama, comedy) based on means-end chain theory. The research used structured APT laddering questions and 251 data was analysed. Through such analysis, category difference by stage and relationship difference were identified and hierarchical value map was compared. There are four different value ladders: first is attributes, functional consequences, psychological consequences, and final value. The result shows that on news program the basic function is viewers are want to visual factor and quickly acquire social news and they pursue a value of personal social relationship. Whereas, on drama program, the viewers are reflected by around person, and they selected a program based on closed related person. In addition, the viewers are influenced by program's social nomination, production's brand in drama, and performer's nomination, producer and program prominence on comedy. The program selection is highly correlated on program selection's credibility, vital energetic life, and social relationship. The results shows that there was no significant difference between low involvement group and high involvement group for main category involvement group respondents.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.6
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• pp.666-673
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• 2014

Finite Element Method(FEM) is the essential tools for analyzing structural and vibration problem. But common commercial program is high-priced and the usage is not easy. Hereby the authors developed FEM program by using Matlab, whose usage is very simple and whose performance is very high. For the convenience of use and calculating efficiency Component Mode Synthesis Method is adopted, which divides a structure by some sub-structures for easy handling, analyzes them by parts and analyzes the structure with encompassing Degrees of Freedom(DOF). And encompassed DOF could be restored to full DOF. To confirm the accuracy the program was applied to a flat plate, and the results were compared to experiment, and good agreements were achieved. The developed program is going to be opened to public.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.15 no.10
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• pp.857-867
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• 1990

Sine CAM structure is regular structure as that of RAM of PLA, CAM generator program is easy to implement. This program outputs CAM layout in the form of CIF(Caltech Intermediate Format) and graphic display program is debugging or displaying CAM generator output, which are implemented on PC/AT with MS C(5.0) graphic library and C language. CIF parser is programmed with YACC(Yet Another Compiler Compiler) and LEX (Lexical Analyzer) in order to flat the CIF data. For the purposed of plotting the layout output using ROLAND XY plotter is developed. By combining these program described above, from CIF generation to layout plotting can be executed on pull-down menu according to user's option.

• Journal of the Korean housing association
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• v.10 no.2
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• pp.175-183
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• 1999

This study aims at modeling the compositional method in the architectural space and shape. The composition of space is composed of the position and the area in space. Therefore these elements are established to the functional program applied at the behavioral data. The element of spatial structure is position and scale in space, and the composition of spatial shape is developed repitionally to the combination of build-up method. The functional program is being expertised and the scale in building being lager, the importance of functional program is increased. Applied at data of the functional program at spatial structure, the process is developed to the method of combination. The purpose of this study is approached at the degree of application in modeling on the compositional method in architectural space and shape, which is a fundamental aspect on the quantitative analysis of architectural space.

• 한국전산유체공학회:학술대회논문집
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• 2010.05a
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• pp.524-529
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• 2010

In the present study, a CFD program is developed for the Fluid-Structure Interaction(FSI) analysis. The non-staggered, non-orthogonal, and unstructured grid system was also used to handle the complicated geometries in the program. In order to validate the capabilities of the developed CFD program, various models are investigated by using unstructured and nonorthogonal meshes. The predicted results are a good agreement with analytic solution, experimental data and commercial software. And also PISO algorithm is applied for transient flow analysis. The cyclic boundary condition and baffle cell are developed in order to improve the effectiveness of the calculation for complex geometry.