• The Journal of the Acoustical Society of Korea
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• v.22 no.8
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• pp.680-686
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• 2003

Digital waveguide model is a general method that is used in physical modeling of musical instruments. Wave motion is analyzed by time or by space in digital waveguide model. Because sampling is made via time, it is general that musical instrument model is described by wave motion of time. In this paper, we synthesized the musical instrument sound by adding instrument body model to the spatial based string model. In this way, we could improve sound quality and process musical instrument model's tone control variables effectively. We explained about delay error that happens in string and body in space based sampling and showed method to process fractional delay using FD (Fractional Delay)filter. Finally, we explained the relation between tone quality and number of delays. And we also compared the result with time base digital waveguide model.

• Proceedings of the Acoustical Society of Korea Conference
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• 1996.10a
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• pp.42-45
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• 1996

잔향시간이 긴 실내의 전달함수의 모델링에 있어서 , 일반적인 플 밴드 MA 모델에 기초한 적응 필터를 이용한 경우에는, 많은 필터 차수를 필요로 하고 적응 시간이 길어지는 문제점이 있다. 본 논문에서는 필터 차수를 감소시키고 수렴 특성을 향사시키기 위해서, 각 입출력 신호를 몇 개의 주파수 대역으로 나우어서 각각의 주파수 대역에 대새서 적응 처리 과정을 행하는 서브밴드 MA 모델을 이용한 적응디지털 필터 처리 방법을 제안한다. 컴퓨터 시뮬레이션 서브밴드MA 모델을 이용한 디지털 적응 필터 처리과정의 유효성을 나타냈었다.

• Journal of Digital Convergence
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• v.10 no.10
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• pp.447-456
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• 2012

In space design or form design step, recognized necessity of digital design practical use. Also, deduced systematized analysis method that can use various function of CAD system actively. These method can promote the practical use because third dimensional digital design escapes plan and design process in concept that get presentation result after is completed, establishes role of effective and systematic digital design at planning and design of space or form. This uses by a design tool that ease designer's judgment and space and form analysis in architectural planning and design process that third dimension digital design is not part by a simplicity design tool. Share and takes advantage of digital design process method that is deduced in this study, need continuance of connection study for more effective and systematic digital design methodology deduction. Need public ownership of teaching material development and teaching method that can deliver extended third dimension digital design process.

• Journal of Korean Library and Information Science Society
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• v.52 no.4
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• pp.179-203
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• 2021

This study aims to grasp the key issues and the direction for digital divide research in South Korea. Based on the 488 KCI journal articles published between 2003 and 2020, the authors analyzed the changes in the number of articles per year and the subject areas of journals. Furthermore, the topic modelling and keyword network anlaysis were applied to identify the subjects of research. The main findings can be summarized as follows: first, there was a stable trend for a while after the number of articles had increased by the year of 2007, and then there has been a sharp increase since 2019. Second, digital divide research has been conducted from diverse fields including social science, multidiscipline, and engineering. Third, the six subject areas were identified which are 'digital divide among regions', 'digital divide among people with disabilities', 'technical environment of digital divide', 'divide from information use and its consequence', 'legal and institutional environments of digital divide', and 'digital divide of the elderly'. Finally, it was shown that the areas of 'divide from information use and its consequence' and 'technical environment of digital divide' have attracted attention recently.

• The Journal of the Acoustical Society of Korea
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• v.20 no.1
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• pp.3-12
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• 2001

In physical modeling of plucked string instruments, the vibration of a string is typically simulated by the linear system. Currently the Digital Waveguides of J.O.Smith[1] are widely used to get a high quality sound of the plucked string instrument. He used the wave equation to derive the Digital Waveguides and emphasized the time variable. In this thesis, new model of plucked string is proposed to improve the sound quality emphasizing the spatial variable of the wave equation. In our model, we used the fixed sampling interval which is not dependent on the speed of the wave. So we could get more detailed description of wave movement by the time variable. As a result, the new model could produce a higher quality sound of plucked string instrument.

• Digital Contents
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• no.4 s.143
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• pp.101-101
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• 2005

한국데이터베이스진흥센터는 제니시스 기술과 공동 주관, 한국CA 후원으로 3월 17일 한국과학기술단체총연합회 대강당에서 ‘데이터 모델링 및 DB설계 핵심 기법 30題세미나’를 개최했다. 데이터 모델링 및 DB설계를 주제로 한 이 세미나에서는 EA도구의 이해 및 전략적 적용, 데이터 모델링 도구를 통한 활용사례 등 다양한 DB 실무 기법을 다뤘다.

• Journal of Digital Convergence
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• v.17 no.8
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• pp.105-113
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• 2019

The purpose of this study is to analyze cyber security risk modeling of critical infrastructure, draw out limitations and improvement measures. This paper analyzed cyber security risk modeling of national critical infrastructure like as electricity sector, nuclear power plant, SCADA. This paper analyzed the 26 precedent research cases of risk modeling in electricity sector, nuclear power plant, SCADA. The latest Critical Infrastructure is digitalized and has a windows operating system. Critical Infrastructure should be operated at all times, it is not possible to patch a vulnerability even though find vulnerability. This paper suggest the advanced cyber security modeling characteristic during the life cycle of the critical infrastructure and can be prevented.

• Proceedings of the Korea Society for Simulation Conference
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• 2004.05a
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• pp.48-56
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• 2004

최근 모델링 및 시뮬레이션 분야에서는 HLA에서 정의하듯이, 여러 가지 시뮬레이션이 동일한 환경에 참여하여 동시에 상호작용 하는 분산 시뮬레이션을 추구하고 있다. 따라서, 이미 모델링 되어 있는 데이터를 재사용하고 확장할 수 있는 방법이 중요해지고 있다. 미국 국방부에서는 이러한 목적으로 합성 환경의 표현과 교환을 위해 SEDRIS와 같은 표준 개념들을 만들고 있으며, 산업계에서의 모델링 및 시뮬레이션 영역에서도 역시, 호환성과 원가절감의 측면에서 표준의 개념을 도입하기 위한 노력이 진행되고 있다. 본 연구에서는, 상업용 디지털 생산 시뮬레이션 솔루션인 DELMIA에서 사용하는 데이터와, 합성 환경의 표준인 SEDRIS 데이터간의 매핑 방법을 설계하고 구현하였다. 이를 통해, 환경 데이터의 표준 기술인 SEDRIS를 DELMIA와 같은 상업용 디지털 생산 시뮬레이션 데이터를 표현하고 교환하는 표준으로서 활용의 가능성을 검토하였다.

• Proceedings of the Korean Nuclear Society Conference
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• 1997.10a
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• pp.317-322
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• 1997

앞으로 건설되는 원전의 계측제어계통은 디지털 기술로 설계될 전망이다. 그러나 디지털 기술을 원전 계측제어계통에 적용하는데 있어서 디지털 기술이 원전의 안전성이나 신뢰도에 영향을 미치지 않는다는 사실을 보증하여야 하며, 디지털계통의 기능과 성능에 대한 확인/검증은 원전에 설치되기 전에 수행되어야 한다. 계측제어 시험검증설비의 목적은 새롭게 개발되는 디지털 제어 및 보호 알고리즘, 경보축약 알고리즘 또는 운전지원계통등의 성능을 검증하기 위함이다. 시험검증설비의 소프트웨어는 웨스팅하우스형 993 MWe 가압경수로를 모델링한 수학적 모델링과 시험검증설비를 운용하기 위하여 필요한 종합운용프로그램으로 구성된다. 하드웨어는 공학용 워크스테이션, 시험용 패널, 개발되는 계통과의 인터페이스를 위한 VXI 인터페이스 모듈, 그리고 공유메모리의 값을 시험대상 시작품으로 전송하는 Ethernet 모듈 등으로 구성된다. 사용자 인터페이스로 할덴 원자로 프로젝트에서 개발된 Picasso 그래픽 도구를 이용한 화면과 60개의 주요변수의 값을 CRT에 표시하는 기능을 제공한다. 계측제어 시험검증설비를 응용한 계측제어계통 시작품은 정상운전 및 과도상태에서 적절한 시험결과를 제공하였다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.25 no.1
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• pp.19-30
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• 2007

Modeling 3D buildings is an essential process to revive the real world into a computer. There are two ways to create a 3D building model. The first method is to use the building layer of 1:1000 digital maps based on high density point data gained from airborne laser surveying. The second method is to use LiDAR point data with digital images achieved with LiDAR. In this research we tested one sheet area of 1:1000 digital map with both methods to process a 3D building model. We have developed a process, analyzed quantitatively and evaluated the efficiency, accuracy, and reality. The resulted differed depending on the buildings shape. The first method was effective on simple buildings, and the second method was effective on complicated buildings. Also, we evaluated the accuracy of the produced model. Comparing the 3D building based on LiDAR data and digital image with digital maps, the horizontal accuracy was within ${\pm}50cm$. From the above we derived a conclusion that 3D building modeling is more effective when it is based on LiDAR data and digital maps. Using produced 3D building modeling data, we will be utilized as digital contents in various fields like 3D GIS, U-City, telematics, navigation, virtual reality and games etc.