• Proceedings of the Computational Structural Engineering Institute Conference
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• 2004.04a
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• pp.87-94
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• 2004

A number of approximate techniques have been developed to calculate the eigenvalues in a reduced manner. These schemes approximate the lower eigenvalues that represent the global behavior of the structures. In general, sequential elimination has been widely used with reliability. But it takes excessively large amount of time to construct a reduced system. The present study proposes two-level condensation scheme(TLCS). In the first step, the candidate elements are selected by element-level energy estimation. In the second step, master degrees of freedom are selected by sequential elimination from the candidate degrees of freedom linked to the selected elements in the first step. Numerical examples demonstrate that the proposed method saves computational cost effectively and provides a reduced system which predicts the accurate eigenvalues of global system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.10
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• pp.4411-4417
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• 2012

The present study proposes the optimization of wing structure base on reduced model which assures the solution accuracy and computational efficiency. Well-constructed reduced model assures the accurate result in the eigenvalue problem, dynamic analysis or sensitivity of design optimization. Reduced system is classified into the reduce-order model based on structural modes and the reduced system based on degrees of freedom. Because this study uses the reduced system based on degrees of freedom, it is important to select the dominant degrees of freedom properly. For this work, robust selection method, two-level selection scheme, is employed and IRS(Improved Reduced System) is applied to construct the final reduced system. In the optimization process based on the reduced system, all of the equivalent stress, eigenvalue and design sensitivities are calculated from the reduced system. Through a numerical example, it is shown that the present optimization methodology based on the reduction method can provide an optimal results for objective function satisfying constraint condition.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.1316-1321
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• 2003

The systematic method to construct equivalent static load from the given dynamic load is proposed in the present study. Previously reported works to construct equivalent static load were based on ad hoc methods. They may results in unreliable structural design. The present study proposes a selection scheme of degrees of freedom(d.o.f) for imposing the equivalent static loads. The d.o.fs are selected by Two-level condensation scheme(TLCS). TLCS consists of two two-steps. The first step is the energy estimation in element-level and the second step consists of the traditional sequential elimination precudure. Through several numerical examples, the efficiency and reliability of proposed scheme is verified.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.666-669
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• 2005

본 논문에서는 3차원 형태로 체적 데이터를 효율적으로 랜더링 하기 위해서, 체적 데이터의 특징점을 추출하고 이를 이용하여 3차원 형태로 복원한다. 여기서, 3D Point(Vertext)를 이용하여 체적 데이터를 랜더링하고자 하여 체적소들에 대해 특정한 3D Points 추출하는 PEF 과정과 랜더링 과정을 담당하는 정점 변환 파이프라인 과정을 제안한다. 일반적으로, 고화질의 광선 추적 랜더링 처리의 경우 계샨량이 많아 그 만큼 랜더링 속도가 떨어져 체적에 대한 다른 ?A너링 기법들이 많이 제안되고 있지만, 본 논문은 다른 각도로의 접근하고자 하여, 기존의 광선 추적에 비해 저화질과 매끄럽지 않는 영상을 나타내지만, 추출된 데이터만 고려하기 때문에 계샨량을 많이 줄일 수 있어 처리속도가 개선되어 졌을 볼 수가 있다. 또한, 본 논문에서 기존의 광선 추적 기법에서 표현하는 회전, 절단, 축소/확대의 기능을 그대로 OpenGL을 이용하여 본 논문에서 제안한 처리 단계로 하여 3차원 랜더링 프로그램 제작 하였다.

• The Journal of the Convergence on Culture Technology
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• v.7 no.2
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• pp.157-163
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• 2021

This study attempted to find individual reasons for inducing cybercrime. The survey was conducted targeting investigators and security experts on 11 types of cybercrime. There are 16 internal factors that cause crime and classified according to Maslow's 5 steps. As a result of the survey on a total of 176 items, the credibility of the Cronbach's Alpha coefficient was 0.925. The result of the factor analysis is as follows. Factor analysis results are maslow phase 1 physiological desire is commercial, sykes. Phase 2 safety desires are not punishable and crowd. The three-stage social desire is impulsiveness, indifference, etc. The fourth stage of respect is anonymity and honor. The desire for self-reality in stage 5 has been reduced to indesity, a loss of moderation, morality, and media effects. In conclusion, the physiological desire, the desire for respect for the crime of infringing on the information and communication network, the desire for menstruation, the desire for self-realization for the crime of using information and communication networks, the desire for self-actualization for the crime of illegal content. It was in the order of desire.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.4
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• pp.107-116
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• 2013

This algorithm suggests a method in which a minimum spanning tree can be obtained fast by reducing the number of an algorithm execution. The suggested algorithm performs a select-and-delete process. In the select process, firstly, it performs Borůvka's first stage for all the vertices of a graph. Then it re-performs Borůvka's first stage for specific vertices and reduces the population of the edges. In the delete process, it deletes the maximum weight edge if any cycle occurs between the 3 edges of the edges with the reduced population. After, among the remaining edges, applying the valency concept, it gets rid of maximum weight edges. Finally, it eliminates the maximum weight edges if a cycle happens among the vertices with a big valency. The select-and-delete algorithm was applied to 9 various graphs and was evaluated its applicability. The suggested select process is believed to be the vest way to choose the edges, since it showed that it chose less number of big edges from 6 graphs, and only from 3 graphs, comparing to the number of edges that is to be performed when using MST algorithm. When applied the delete process to Kruskal algorithm, the number of performances by Kruskal was less in 6 graphs, but 1 more in each 3 graph. Also, when using the suggested delete process, 1 graph performed only the 1st stage, 5 graphs till 2nd stage, and the remaining till 3rd stage. Finally, the select-and-delete algorithm showed its least number of performances among the MST algorithms.

• Journal of Digital Contents Society
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• v.12 no.1
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• pp.1-9
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• 2011

JPEG2000 offers the technique which compresses the interested regions with higher quality than the background. It is called by an ROI(Region-of-Interest) coding method. In this paper, we use images including the human faces, which are processed uppermost and compressed with high quality. The proposed method consists of 2 steps. The first step extracts some faces and the second one is ROI coding. To extract the faces, the method cuts or scale-downs some regions with $20{\times}20$ window pixels for all the pixels of the image, and after preprocessing, recognizes the faces using neural networks. Each extracted region is identified by ROI mask and then ROI-coded using Maxshift method. After then, the image is compressed and saved using EBCOT. The existing methods searched the ROI by edge distributions. On the contrary, the proposed method uses human intellect. And the experiment shows that the method is sufficiently useful with images having several human faces.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1045-1046
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• 2011

본 논문에서는 굴곡면 커버내에 전기회로를 구현시 그 동안 포토리소그라피 공정으로 제작된 PCB를 휴대기 등 내부 케이스에 부착하여 전기회로를 구현하였으나 본 논문에서는 PCB없이 직접 케이스인 복합 폴리머소재에 레이저조사에 의해 패턴과 무전해도금으로 전기회로를 직접구현하는 기술이다. 이러한 방법은 제안한 3단계 공정기법에 의해 가능하며, 즉 사출형 복합폴리머소재제작, 소재의 레이저조사에 의한 시드패턴 구현 및 형성시드의 무전해도금에 의한 전도성패턴구현 공정을 통하여 곡면커버의 전기회로구현이 가능하다. 이에 따라 기존의 복잡한 10 단계 이상의 포토리소그라피 공정을 레이저조사에 의한 3단계 공정으로 간소화함으로서 제품의 생산성향상, 다량장비 구입절감, 작업공간축소 및 기타 소재절감 등의 경제적 효과를 얻을 수 있다. 응용분야는 2차원 평면 전기회로 외에 3차원 곡면형상의 제품인 자동차, 휴대폰, 의료기, 센서, 오토바이 등의 커버에 직접회로 응용이 가능하다. 이에 대한 타당성은 실험결과를 통하여 입증하였다.

• The KIPS Transactions:PartB
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• v.8B no.2
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• pp.115-122
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• 2001

퍼지관계 개념에 기반한 BK-FIRM(Bandler-Kohout 퍼지정보검색기법)은 형태론에 입각한 기존의 정보검색기법과는 달리 문서와 용어의 상대적 의미에 근거한 퍼지정보검색기법이다. BK-FIRM은 시소러스 자동 구축 기능, 검색 결과의 퍼지화된 우선 순위 제공과 같은 장점을 가지고 있다. 그러나, BK-퍼지정보검색기법은 높은 시간복잡도(time complexity)의 검색 연산을 내재하고 있어 다양한 분야 적용이 불가능하다. 본 논문에서는 축소용어집합을 이용하여 BK-FIRM의 시간복잡도를 낮춘 A-FIRM(개선된 Bandler-Kohout 퍼지정보검색모델)을 소개하고 이를 정보검색시스템으로 설계 및 구현한 A-FIRS(개선된 Bandler-Kohout 퍼지정보검색시스템)를 구현한다. A-FIRS는 크게 문서베이스와 시소러스를 구축하는 전처리부(preprocess unit)와 사용자의 검색요구를 처리하여 문서를 검색하는 실시간처리부(real-time process unit)로 나누어지며, 각 처리부는 기능적 특성에 따라 4개의 처리단계로 구성된다. A-FIRS는 WWW 기반 환경과 연동하도록 설계되었으며, WWW 환경의 사용자로부터 주어진 검색요구를 처리하여 검색결과를 제공한다.

• The Transactions of the Korea Information Processing Society
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• v.2 no.5
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• pp.733-745
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• 1995

This study is aimed at construction of a translator for a functional programming language. For this goal we define a functional programming language which has lazy semantics and develop a translator for it. The execution model selected is the G-machine-based combinator graph reduction. The translator is composed of 4 phases and translates a source program to a C program. The first phase of the translator translates a source program to a enriched lambda- calculus graph, the second phase transforms a lambda-calculus graph into supercombinators, the third phase translates supercombiantors to a G program and the last phase translates the G program to a C program. The final result of the translator, a C program, is compiled to an executable program by C compiler. The translator is implemented in C using compiler development tools such as TACC and Lex, under the UNIX environments. In this paper we present the design and implementation techniques for developing the translator and show results by executing some test problems.