• Proceedings of the Korea Database Society Conference
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• 1997.10a
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• pp.137-155
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• 1997

이 글에서는 디지털 아카이브 되거나 데이터베이스화 되어있는 영상정보의 저장규모와 이용 시장에 대하여 기술한다. 현재, CD-ROM 타이틀, 비디오 CD 및 DVD 타이틀과 인터네트를 통한 부분적인 이용에 그치고 있는 디지털 영상정보는 무어의 법칙을 따르는 컴퓨터 프로세서 성능 증대, 50 만원대에 20GB용량을 가지는 광자기 디스크의 출현처럼 계속 확장되고 있는 저장용량, Gigabit LAN의 등장과 같이 지속적으로 확대되는 통신 네트워크의 전달용량, 영상기반 렌더링을 이용하는 새로운 가상세계 구축기술 등 그 활용을 가속시키는 여러 요인들에 의해 용도가 큰 폭으로 증가하고 있다. 이에 따라 영상정보는 교육, 의료 등 기본적인 생환산업 분야를 비롯하여 여러 산업 분야의 경쟁력을 강화시킬 수 있는 정보원으로서의 근간이 될 것이다. 이러한 발전의 지속은 기술에 의해서만 보장될 수 있으므로, 영상정보의 디지털 처리, 디스플레이, 저장 등의 디지털 아카이브 관련 기술과 디지털 영상정보의 편집, 저작, 검색, 전송 등에 관련된 분야의 기술 확보를 어떻게 대비해야 할 것인가가 중요한 과제이다.

• Journal of Applied Reliability
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• v.9 no.1
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• pp.1-12
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• 2009

BLDC motors are stored in the devices such as CD-RW, COMBO, DVD-ROM and CD-ROM. It is indispensable to establish reliability assessment criteria for BLDC motors, especially in the world where IT grows rapidly. In this article, reliability certification procedure is given. The reliability certification procedure consists of two separate tests such as quality certification test and lifetime test. The former quality certification test comprises general performance test and environmental test. Items which pass the test undergo lifetime test which guarantees the extent of mean lifetime with certain confidence.

• 한국HCI학회:학술대회논문집
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• 2007.02a
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• pp.869-874
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• 2007

본 논문에서는 CD, DVD, 책과 같은 정보 저장 매체와 디지털 환경을 조합하여, 사용자로 하여금 쉽게 정보에 접근 가능하도록 하는 시스템을 소개한다. 이 시스템에서는 RFID를 이용하여 각 물리적 정보 저장 매체를 디지털 정보와 연계하고, 연계된 디지털 정보를 직관적이고 편리하게 이용 가능하도록 하는 "스마트 퍽"이라는 인터페이스 도구를 사용하여 사용자가 컴퓨터와 상호작용할 수 있도록 한다. 시스템은 PDP 기반의 테이블 디스플레이 장치, 그 위에 나타나는 정보와 직접적이고 직관적인 인터랙션이 가능한 인터페이스 도구인 스마트 퍽, RFID 인식 장치 등으로 구성되었다. 최종적으로는 이 시스템을 이용하여 실제 음악 CD를 디지털 정보로 나타내고, 쉽게 조작하여 재생하는 예시를 보이기로 한다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.10 s.181
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• pp.2513-2519
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• 2000

Free vibration characteristics of an initially stressed CD/DVD disk, which is designed for increasing critical speeds of current optical disks, are analyzed using the Rayleigh-Ritz technique based on variational formulations. Natural frequencies of the new disk depend on membrane stresses caused by disk rotation as well as residual stresses imposed during the cooling process of the injection molding. Critical speeds are calculated for the various initial patterns of radial and circumferential stresses. Initially imposed tensile stresses increase the natural frequencies of all the vibration modes except zero nodal diameter mode, whose natural frequency is independent of circumferential stress. A new disk with initial tensile stress of 0.5MPa is shown to have its critical speed about 30 % higher than the current optical disk.

• KIPS Transactions on Computer and Communication Systems
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• v.5 no.12
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• pp.491-498
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• 2016

Recently leakages of confidential information and internal date have been steadily increasing by using booting technique on portable OS such as Windows PE stored in portable storage devices (USB or CD/DVD etc). This method allows to bypass security software such as USB security or media control solution installed in the target PC, to extract data or insert malicious code by mounting the PC's storage devices after booting up the portable OS. Also this booting method doesn't record a log file such as traces of removable storage devices. Thus it is difficult to identify whether the data are leaked and use trace-back technique. In this paper is to propose method to help facilitate the process of digital forensic investigation or audit of a company by collecting and analyzing BIOS firmware images that record data relating to BIOS settings in flash memory and finding traces of portable storage devices that can be regarded as abnormal events.

• Journal of the Korean Institute of Telematics and Electronics T
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• v.36T no.2
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• pp.32-41
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• 1999

The design method that the structure of double actuators of read-only or read-writable DVD optical pick-up of high density can be compact into the structure of one actuator, is proposed. The designed actuator has the structure of the shaft sliding type in which the moving part can be rotated about the shaft accord to a used optical disc and an objective lens can be switched, and is suspended with magnetic spring. In this actuator, Coulomb's friction is used as damping force and the moving part is designed by finite element method so that the second natural vibration mode can not occur within the servo band. The mock-up of the actuator designed in this paper is made, and its dynamic characteristics is measured and estimated.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.135-135
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• 2007

AgInSbTe물질은 compact disc rewritable(CD-RW)와 rewritable digital versatile disc (DVD+RW)과 같은 상변화 기록매체에 널리 쓰여지고 있다. 본 논문에서는 기존 AgInSbTe조성에 Te가 증가되었을때 변화하는 상변화 특성에 대한 연구를 수행하기 위하여 ($Ag_{3.4}In_{3.7}Sb_{76.4}Te_{16.5})x(Te)1-x$의 조성 (x=1,0.9,0.8,0.7)의 벌크 및 박막시료를 제작하였고 열증착방식을 이용하여 200nm 두께의 박막을 형성하였다. 각 박막은 질소분위기에서 100-300도 범위에 1 시간동안 열처리 하였고 XRD와 UV-ViS-NIR Spectrophotometer룰 통해 각 조성의 구조 및 광학적 특성 분석을 살시하였다. 또한 as-deposited 박막에 대하여 4-point probe를 사용하여 면저항을 측정하였고 AFM (atom force microscopy)을 통해 표면분석을 실시하였다.

• 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 of Mechanical Engineers A
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• v.26 no.5
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• pp.952-959
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• 2002

The natural frequencies of a flexible spinning disk misaligned with the axis of rotation are studied in an analytic manner. The effects of misalignment on the natural frequency need to be investigated, because the misalignment between the axis of symmetry and the axis of relation cannot be avoided in the removable disks such as CD-R, CD-RW or DVD disks. Assuming that the in -plane displacements are in steady state and the out-of-plane displacement is in dynamic state, the equations of motion are derived for the misaligned spinning disk. After the exact solutions are obtained fur the steady -state in-plane displacements, they are plugged into the equation for the dynamic-state out-of-plane motion. The resultant equation is a linear equation for the out -of-plane displacement, which is discretized by the Galerkin method. Based on the discretized dquations, the effects of the misalignment are analyzed on the vibration characteristics of the spinning disk, i.e., the natural frequencies and the critical speed.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.11b
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• pp.817-825
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• 2001

The natural frequencies of a flexible spinning disk misaligned with the axis of rotation are studied in an analytic manner. The effects of misalignment on the natural frequency need to be investigated, because the misalignment between the axis of symmetry and the axis of rotation cannot be avoided in the removable disks such as CD-R, CD-RW or DVD disks. Assuming that the in-plane displacements are in steady state and the out-of-plane displacement is in dynamic state, the equations of motion are derived for the misaligned spinning disk. After the exact solutions are obtained for the steady-state in-plane displacements, they are plugged into the equation for the dynamic-state out-of-plane motion. The resultant equation is a linear equation for the out-of-plane displacement, which is discretized by the Galerkin method. Based on the discretized equations, the effects of the misalignment are analyzed on the vibration characteristics of the spinning disk, i.e., the natural frequencies and the critical speed