• Proceedings of the Korea Information Processing Society Conference
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• 2001.10a
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• pp.55-58
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• 2001

XML 문서의 저장 및 관리 방법으로 관계형 데이터베이스가 많이 사용되고 있다. 그러나 XML과 관계 데이터베이스의 구조상의 불일치로 인해 데이터 손실, 질의처리의 효율성 저하 등과 같은 문제가 발생한다. element의 순환, 다중값을 갖는 attribute들의 처리 등을 위한 별도의 처리방법이 필요하다. 따라서, 본 논문은 효율적인 저장, 관리 및 질의 처리를 고려하여 DTD 기반의 XML 문서를 관계 데이터 베이스에 저장하는 방법을 제시한다.

• Proceedings of the Korea Institute of Convergence Signal Processing
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• 2003.06a
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• pp.256-261
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• 2003

A memory industry is developing rapidly according to the period of the ubiquitous to approach. According to the development of a memory industry, the efficiency of the manufacture is becoming the serious consideration. DC parameter test system was a development low in this research for an efficiency increase of the manufacture. DC parameter test system increase of the manufacture. In the method to measure the output after permit volt and current at element.

• Journal of the Korean Institute of Navigation
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• v.20 no.4
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• pp.99-109
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• 1996

Though median filter is used for removing noise and smoothing image. But, the result of it has distortion around edge. And then, this paper proposes new noise removing algorithm by recursive morphological processing. Basic operation is same each other, but there is some different processing method between recursive morphology and general morphology theory. This recursive morphological filter can be viewed as the weighted order static filter, and then it has a weighted SE(structuring element). Especially using this algorithm to remove the 10% gaussian noise, this paper confirmed that PSNR is improved about 0.642~1.5757 db reserving edge well better than the results of the traditional median filter.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.7 no.2
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• pp.95-111
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• 2003

BDM mixed methods are obtained for a good approximation of velocity for flow equations. In this paper, we study an implementation issue of solving the algebraic system arising from the BDM mixed finite elements. First we discuss post-processing based on the use of Lagrange multipliers to enforce interelement continuity. Furthermore, we establish an equivalence between given mixed methods and projection finite element methods developed by Chen. Finally, we present the implementation of the first order BDM on rectangular grids and show it is as simple as solving the pressure equation.

• Proceedings of the Korea Information Processing Society Conference
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• 2012.04a
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• pp.682-685
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• 2012

NFC(Near Field Communication) 기술은 근거리 무선통신 기술로서 다양한 모드에서의 서비스를 지원한다. 결제, 할인쿠폰 등 각종 기능을 제공하는 수단으로서 통신과 금융이 융합된 모바일 NFC 서비스의 시장이 급성장 할 것으로 전망되고 있다. 그 결과로 NFC Forum, ECMA International 등 관련 단체에서는 모바일 NFC 서비스를 이루는 각 구성요소의 역할, 기능, 보안 요구사항 등을 제시하며 보안의 중요성을 강조하였다. 본 논문에서는 NFC기술과 보안요소(Security Element)에 대해 소개를 하고, 보안 위협과 그에 대한 대응방안에 대해 소개한다.

• Transactions of Materials Processing
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• v.21 no.7
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• pp.403-411
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• 2012

The aim of this study was to predict the results of superplastic forming on magnesium alloy, by considering the grain growth using numerical simulations. Superplastic behavior of AZ31 alloy was investigated through a set of uniaxial tensile tests that cover the forming temperatures ranges from 375 to $450^{\circ}C$. All the material parameters in the model, which consists of a constitutive equation and a grain growth equation, were determined. The model was used in the finite element analysis for uniaxial tensile tests and superplastic blow forming, through a user-subroutine available within ABAQUS. From this study, the effect of grain growth during forming was evaluated. The results show that it is essential to include the effect of grain growth in predicting the behavior during superplastic forming of this magnesium alloy.

• Transactions of Materials Processing
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• v.21 no.7
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• pp.420-425
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• 2012

A new model is suggested for the prediction of radial displacements of a roll in order to analyze multi-high rolling mills. The model was developed from predictions based on finite element simulations. This model utilizes the compliance coefficient, which is expressed as a function of three dimensionless parameters, and is approximated by using the same interpolation function as used in the finite element method. The prediction accuracy of the model is demonstrated through comparison with the predictions from the FE model.

• Korean Journal of Computational Design and Engineering
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• v.1 no.1
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• pp.65-75
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• 1996

This paper describes an automatic finite element(FE) mesh generation for three-dimensional structures consisting of free-form surfaces. This mesh generation process consists of three subprocesses: (a) definition of geometric model, i.e. analysis model, (b) generation of nodes, and (c) generation of elements. One of commercial solid modelers is employed for three-dimensional solid and shell structures. Node is generated if its distance from existing node points is similar to the node spacing function at the point. The node spacing function is well controlled by the fuzzy knowledge processing. The Delaunay method is introduced as a basic tool for element generation. Automatic generation of FE meshes for three-dimensional solid and shell structures holds great benefits for analyses. Practical performances of the present system are demonstrated through several mesh generations for three-dimensional complex geometry.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2004.04a
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• pp.389-395
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• 2004

We consider the interface between the parallel distributed memory multifrontal solver and the finite element method. We give in detail the requirement and the data structure of parallel FEM interface which includes the element data and the node array. The full procedures of solving a large scale structural problem are assumed to have pre-post processors, of which algorithm is not considered in this paper. The main advantage of implementing the parallel FEM interface is shown up in the case that we use a distributed memory system with a large number of processors to solve a very large scale problem. The memory efficiency and the performance effect are examined by analyzing some examples on the Pegasus cluster system.

• Transactions of Materials Processing
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• v.26 no.2
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• pp.108-114
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• 2017

Titanium based implants are known to improve their osseointegration by controlling surface roughness from nanometers to micrometers. Implants continuously and/or repeatedly receive irregular loads in the human body, and require a deeper understanding of the tensile and fatigue properties that can determine the fracture characteristics of the materials. In this study, the plastic deformation behavior which depends on the surface geometry of the materials during tensile tests was analyzed using the finite element method. As a result, the tensile properties were greatly decreased with increasing the sharpness of the surface. On the other hand, the average roughness had no significant effect on tensile properties. This investigation shed a light on developing titanium implants with improved osseointegration by surface treatments.