• Proceedings of the IEEK Conference
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• 1999.11a
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• pp.212-215
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• 1999

High-speed device is essential to optoelectric IC for optical storage system such as CD-ROM, DVD, and to ADC for high-speed communication system. This paper represents the BiCMOS process which contains high-speed SAVEN bipolar transistor and analyzes the frequency and switching characteristics of it briefly. Finally, to prove that the SAVEN device is adequate for high-speed system, latched comparator operating at 500MHz is designed with the SPICE parameter extracted from BiCMOS device simulation.

• TTA Journal
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• s.61
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• pp.128-133
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• 1999

우정성은 통신백서(1998년 통신에 관한 현황 보고)를 5월 26일 각료 회의 후에 공표하였다. 이번 백서는 $\ulcorner$디지털 네트워크 사회 개막$\~$변해가는 라이프스타일$\~$$\lrcorner$이라는 제목의 특집호로 구성되었다. 본 특집에서는 급속히 보급되고 있는 인터넷, 휴대전화, CS 디지털 방송 등의 미디어가 일, 취미$\cdot$오락, 학습 등의 생활에 주는 영향을 분석하고 있다. 또 정보 literacy의 일$\cdot$미 비교 등도 실시하여 $\ulcorner$다양한 선택$\lrcorner$과 $\ulcorner$자유로운 참가$\lrcorner$의 기회가 제공되어,$\ulcorner$개성 발휘$\lrcorner$를 할 수 있는 보다 풍부하게 열린 $\ulcorner$디지털 네트워크 사회$\lrcorner$실현을 위한 과제를 제시하고 있다. 이외에 본 백서에서는 정보통신의 현황분석이나, 정보통신산업의 일$\cdot$미 비교, 사이버 비즈니스의 특성 분석, 도도부현의 정보화 분석 등을 나타내고 있다. 또한 작년에 이어, CD-ROM판을 첨부한 책자 및 DVD-ROM판 백서를 판매하고 있다. 금년부터 일본의 백서로는 처음으로, 인터넷상에 공표일 당일부터 백서 전문을 게재하였다. 1998년 백서는 3장으로 구성되어 있는데 각 장의 포인트를 소개하고자 한다.

• Proceedings of the Korea Multimedia Society Conference
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• 2003.05b
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• pp.832-835
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• 2003

전자책이란 저작물의 내용을 디지털 데이터로 CD-ROM, DVD 등 기록매체 또는 저장장치에 수록, 유·무선 통신망을 통해 전용 단말기나 컴퓨터로 이용할 수 있는 출판물을 의미한다. 전자책은 다양한 형태로(HTML, PDF, XML) 제작돼 표준이 없어 별도의 단말기를 개발 보급해야하는 문제와 함께 전자책 산업의 중복투자를 발생시켜 활성화에 어려움을 겪어왔다. 2002년 산업자원부 기술표준원은 이러한 문제를 해결하기 위해 상호운용성 등이 뛰어난 XML에 기반한 전자책 문서 표준(EBKS 1.0)안을 국가표준으로 제정하였다. 교육인적자원부에서도 2002년 '교과용 도서에 관한 규정' 을 개정, 주교재와 보완교재의 구분을 폐지해 음반이나 영상, 전자저작물 등을 활용한 전자교과서 및 지도서를 제작할 수 있도록 했다. 이러한 시대흐름에 발맞추어 본 연구에서는 XML Schema를 활용한 중학교 컴퓨터 과목의 전자교과서 문서 표준을 개발해 보고자 한다. EBKS를 비롯한 기존 연구의 대부분은 XML DTD를 이용한 표준 개발이 중심이었으나 DTD가 가진 제한점들로 인해 이미 XML Schema의 사용이 권고되고 있다.

• Journal of the Korean Society for information Management
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• v.28 no.3
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• pp.103-121
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• 2011

This study is to seek to apply resource types of RDA to KCR4. It is difficult to choose appropriate term and to embody FRBR model because GMD of KCR4 is the mixture of content-based vocabularies and carrier-based vocabularies. SMD is to need to reflect the current technological terms. Resource type of RDA was already developed to overcome limitation of AACR2's GMD, and would affect the world cataloging environment, therefore it is need to apply resource type of RDA to Korean cataloging rule. For this study, case study and survey were used. In case study, it was to scan all GMD term for one university library to build by programming and to grape librarian and users' potential need. In the survey by cataloging librarian, it was to figure out the current description of resource type in university library and to test RDA resource type. As a result, it was needed to revise the vocabulary to the obvious and user-understandable list. Also it was different in correction rate in RDA testing by resource type. Based on the case study and the survey, RDA resource type was applied to KCR4 resource list by adding term such as computer game in content type, and by inserting terms such as DVD, CD-ROM, Blu-Ray, computer file in carrier type. It also applied RDA description method and display means to KCR4. This study would apply RDA resource type to KCR4 and contribute to revise KCR4 resource type.

• Journal of Institute of Control, Robotics and Systems
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• v.10 no.5
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• pp.402-410
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• 2004

To obtain a good tracking performance in an optical disk drive servo system, it is essential to attenuate periodic disturbances caused by eccentric rotation of the disk. As an effective control scheme for enhancing disturbance attenuation performance, disturbance observers (DOBs) have been successfully applied to the track-following servo system of optical disk drives. In disk drive systems, the improvement of data transfer rate has been achieved mainly by the increase of disk rotational speed, which leads to the increase of the disturbance frequency. Conventional DOBs are no longer effective in disk drive systems with a high-speed rotation mechanism because the performance of conventional DOBs is severely degraded as the disk rotational frequency increases. This paper proposes a new DOB structure for effective rejection of the disturbance in optical disk drives with a very high rotation speed. Asymptotic disturbance rejection is achieved by adopting a band-pass filter in the DOB structure, which is tuned based on the information on the disturbance frequency. In addition, performance sensitivity of the proposed DOB to changes in disk rotational frequency is analyzed. The effectiveness of the proposed DOB is verified through simulations and experiments using a DVD-ROM drive.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.9
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• pp.1905-1913
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• 2002

Using the finite element method, this study investigates the dynamic time responses of a flexible spinning disk of which axis of rotation is misaligned with the axis of symmetry. The misalignment between the axes of symmetry and rotation is one of the major vibration sources in optical disk drives such as CD-ROM, CD-R, CD-RW and DVD drives. Based upon the Kirchhoff plate theory and the von-Karman strain theory, three coupled equations of motion for the misaligned disk are obtained: two of the equations are for the in-plane motion while the other is for the out-of-plane motion. After transforming these equations into two weak forms for the in-plane and out-of-plane motions, the weak forms are discretized by using newly defined annular sector finite elements. Applying the generalized-$\alpha$ time integration method to the discretized equations, the time responses and the displacement distributions are computed and then the effects of the misalign ment on the responses and the distributions are analyzed. The computation results show that the misalignment has an influence on the magnitudes of the in-plane displacements and it results in the amplitude modulation or the beat phenomenon in the time responses of the out-of-plane displacement.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.10 s.103
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• pp.1148-1159
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• 2005

In this paper, the various uncertainties generated in an optical disk drive (ODD) and the robust servo designs considering the uncertainties are studied. First, the brief introduction an ODD and the servo error tolerance of it are discussed. Then, the classifications of uncertainty and the concept of relative stability are introduced. Considering the uncertainty of an ODD, two robust control approaches are applied: (i) mixed sensitivity approach in H$\infty$ control theory for unstructured uncertainty, (ii) QFT for structured uncertainty Finally, the designed controllers are realized by DSP, and these controllers are applied to a commercial DVD-ROM drive. From these experiments, we prove that the designed robust controllers have more good disturbance rejection performance and robustness when it is compared to the conventional lead-lag controller.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.50 no.1
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• pp.1-9
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• 2001

In this paper, the general research on the analysis of the vibration due to magnetic exciting force in the small brushless DC(BLDC) motor, which is used in the Digital Versatile Disk(DVD) ROM driving system, is performed. The first part of the study is the analysis of the magnetic exciting force in the air gap region. As a verification of the exciting force by numerical analysis, the magnetic exciting force distribution in the air gap region is computed by using Reluctance Network Method(RNM). In addition, the effect of the eccentricity on the magnetic exciting force is discussed. The other part of the research is the structural analysis of the rotor structure of the BLDC motor. The matural mode analysis of the rotor structure is performed, and the vibration response due to magnetic exciting force is found. As a result of the procedures, the basic estimation of the effect of the magnetic exciting force on the vibration of BLDC motor is suggested.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.4
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• pp.764-774
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• 2002

Dynamic behaviors are analyzed for an automatic ball balancer (ABB) with triple races, which is a device to reduce the unbalanced mass of optical disk drives (ODD) such as CD-ROM or DVD drives. The nonlinear equations of motion are derived by using Lagrange's equations with the polar coordinate system. It is shown that the polar coordinate system provides the complete stability analysis while the rectangular coordinate system used in other previous studies has limitations on the stability analysis. For the stability analysis, the equilibrium positions and the linearized perturbation equations are obtained by the perturbation method. Based on the linearized equations, the stability of the system is analyzed around the equilibrium positions; furthermore, to confirm the stability, the time responses for the nonlinear equations of motion are computed by using a time integration method and experimental analyses are performed. Theoretical and experimental results show a superiority of the ABB with triple races.

• Proceedings of the Korean Printing Society Conference
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• 2001.06a
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• pp.63-77
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• 2001

PDF(Portable Document Format) is a file format that Adobe advances postscritp technique and use in managing document information or electric publishing(internet, CD-ROM, DVD). PDF is a devised document type for being able to read and print anywhere, independent of OS, printer type, resolution, and the kind of computer etc. Because this includes a compressing function, it transfers document through a small size of file in internet or intranet. In addition, that is a file format has various advantages-sharing of information and transfering documents in on line or off line environment. In this paper, we developed electronic document system using PDF format. Electronic document system consists of filter, automatic indexing, special searching system and web server. The information used in this paper is database made using Zwon\`s DocuCom. The filter recognizes various kinds of document structure. And according to property of document, it produces ASCII output. In addition to processing various formats of document, the filter can extract keywords in documents of MS WORD, Excel, Powerpoint, PDF, CAD etc. This filter uses the structure of window printer drive and can extract the information for text, page, font type and size from relevant document. The automatic indexing recognizes the formatted tag of document form ASCII text produced by filter and extracts adequate keyword to structure and property of document. PDF electronic document systems proposed in this paper can be used in Internet, PC communication. Users can choose and read electronic documents by two ways. First, users can choose and read relevant books using PDF electronic document homepage. Second, users can use PDF integrated-search system. User can search after inputing keyword and choose reference field and type of data. But, now, PDF products of Adobe can\`t support the Korean character. If this problem is resolved, we thick that PDF applications system looks active. Although there is limited function in case of using Zwon DocuCom used in this study, we think that there isn\`t a great deal of difficulty in electronic document and building digital database.