• 한국광학회:학술대회논문집
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• 한국광학회 2000년도 제11회 정기총회 및 00년 동계학술발표회 논문집
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• pp.28-29
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• 2000

최근, 통신, PC등의 보급과 함께, 메모리기기의 발전이 급속히 이루어 지고있다. 이 중에서 광기억장치는 기록 및 재생용량을 증가시키는 기술이 활발히 연구되어 왔다. 본고에서는 대용량기기의 대표적인 DVD(Digital Versatile Disc)에 있어서, 핵심광학기술로 각광을 받고있는 CD호환을 위한 환형(annular type) lens의 특성을 고찰하였다. 그리고, 반도체 메모리, Hard disk등도 고밀도연구가 지속적으로 연구되고있으며, 이에 대응되는 광기억장치의 기술로서 근접장 광학이 최근 활발히 연구되고있다. 근접장에 의한 고개구수를 달성하기 위한 효율적인 대물렌즈로서 종래의 굴절렌즈만이 아닌 반사광학계도 사용한 굴절-반사광학계 (Cata-dioptric Optics)를 응용한 Solid Immersion Mirror (SIM)에 관한 특성을 살펴보았다. (중략)

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 춘계학술대회논문집
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• pp.195-199
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• 2004

Recently, optical disc drives are required to have high density and capacity in according with development of high definition images and rapid increase of various informations. Consequently, the numerical aperture becomes larger, the wavelength of laser is coming to be short. However, it deteriorates rolling mode effect on an optical pickup actuator. Therefore, this paper proposes new design and optimization of tracking coils for reducing it. First, we verify that discord between the center of force and the center of mass by restrictions of design condition is an important factor of rolling mode effect. Then, in order to reduce it, we propose new design parameters of tracking coils. Finally, we reduce rolling mode effect through optimization of tracking coils using Taguchi method and response surface method.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.1333-1334
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• 2007

Page-oriented angle multiplexing Holographic data storage system is the one of promising techniques for high capacity and data transfer rate, but its size and narrow tilt margin is pointed as a demerit. To overcome this weak point, in this paper, 2-axis deck mechanism for compensation of disc is employed to Compact size Holographic Data Storage (CHDS) which consists of minimized optical components and small 2-axis actuator moving linear & angle direction. Compensation of radial/tangential disc tilt with 2-axis deck mechanism is demonstrated.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 2009년도 한국우주과학회보 제18권2호
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• pp.34.3-34.3
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• 2009

We have investigated the recent star formation history of the nearby galaxies using the SDSS optical and Galex UV data. To everyone's surprise, we found that roughly 30 percent of elliptical galaxies had a residual star formation in the last billion years, suggesting that residual star formation has been common even in ellipticals. Galaxy evolution models based on semi-analytic prescriptions including AGN feedback reasonably reproduce the star formation properties of elliptical galaxies. However, we found that the current galaxy models miserably fail to reproduce the star formation properties of satellite disc galaxies in cluster environments. Satellite disc galaxies in models are overly star-formation quenched in comparison to observation. Detailed investigations led us to conclude that this is due to the use of inaccurate prescriptions for the gas content evolution in the model. I present a solution to the problem by adopting more realistic physical prescriptions.

• 정보저장시스템학회논문집
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• 제2권3호
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• pp.196-200
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• 2006

We are developing a phase change etching technology using an inorganic photoresist of GeSbTe film which is the recording material of the phase change disc. A selective etching phenomenon between amorphous and crystalline states can be utilized with an alkaline etchant. Phase-change pits could be formed using this technique, in which the etching selectivity is strongly dependent on the concentration of the etchant. The degree of etching was investigated by the transmittance between crystalline and amorphous films after the wet-etching. The pits patterned on the disc could be observed by AFM after wet-etching.

• Macromolecular Research
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• 제9권6호
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• pp.313-318
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• 2001

The present study relates to a method of manufacturing 100$\mu\textrm{m}$ thick cover layer for the high density digital versatile disc system (HD-DVD), which uses a high numerical aperture of 0.85 at 405 nm wavelength. Spin coating technique was investigated as means for manufacturing the cover layer within sufficient margins of thickness variation and with good mechanical properties including small radial and tangential tilts. The influence of processing variables such as spinning speed, spinning time, and dispensing position was investigated. The effect of viscosity of UV-curable resin was also investigated.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 추계학술대회논문집 II
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• pp.780-785
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• 2001

A moving-magnet type pickup actuator is proposed, which has the back-yoke to improve th sensitivity. Through the magnetic path analysis, we can find that the flux density is increased i the air gap by the pole assignment of magnet and the adding of back-yoke can reduce the flu leakage and induce 40％ up of flux density. Experimental results show that the sensitivity i improved in the tracking direction, however, the improvement doesn't occur in the focusing direction. Finally, the compensation performance is tested in HD-DVD system. And it is verifie that the actuator can compensate the disc tilt of ${\pm}$0.7$^{\circ}$.

• 도시과학
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• 제10권1호
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• pp.11-20
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• 2021

In this study, the vibration characteristics were theoretically analyzed by modeling a free isotropic rotating disk with an outer periphery with a fixed inner periphery, paying attention to disks used as storage devices for information devices, especially magnetic disks, magneto-optical disks, and compact disks in which the head and disk are non-contact. Iluminate with Composite materials represented by fiber-reinforced plastics (FRP) have high specific strength (strength/density) and specific stiffness (narrowness/density). It is used in the elements, and its use is rapidly expanding. Under this circumstance, the disk currently manufactured using an isotropic material made of various plastic materials such as aluminum or polycarbonate as a base material is an extremely anisotropic material made of a composite material, and the circumferential stiffness of the disk is made of reinforcing fibers in the circumferential direction. It is modeled as an anisotropic rotating disk with increased, and its influence on the vibration characteristics is revealed.

• 한국정보통신학회논문지
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• 제14권6호
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• pp.1435-1440
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• 2010

본 논문은 디지털 비디오 타이틀 제작 업체가 디스크 제작을 완료한 후 디스크 복제방지를 위한 목적으로 디스크의 일부영역에 타이틀 업체의 고유ID를 기록하는 후처리 암호화 기록장치에 대한 시스템을 제시한다. 그 방법으로서 FPGA를 이용하여 광디스크의 메모리블럭 동기화 신호인 SYNC.를 검출하고, 기록(Write)을 위한 다중펄스(Multi Pulse)를 발생시키는 기록 패턴을 설계한다. 그리고 사용자가 광 디스크의 데이터영역을 어느 곳이라도 자유자재로 기록이 가능하도록 FPGA로서 기록하는 방법을 제시하고 설계한다. 이러한 디지털 비디오 광 디스크의 비기록 데이터영역을 사용자 임의대로 기록하는 시스템을 개발함으로서 소프트웨어 복제 방지에 효과적으로 대응이 가능하며, 향후 고밀도 광 디스크의 암호화 기록에도 응용이 가능하다.

• 한국인쇄학회지
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• 제30권3호
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• pp.23-33
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• 2012

We studied simultaneously the electronically written data affected in the use of thermal transfer discs and the recoding strategy between recoding drives for the stable long term preservation of optical discs which are commonly used in an electronic data storage device. The most important thing in the archiving preservation might be a choice of a device, however the use of thermal transfer recording discs is not good for long term data preservation because the thermal effect on the recoding data is critical which means that the data are recorded not under best condition but under bad condition. We inspect the strategies of recoding data from 12 brands of optical discs and drives of 7 brands and it turns out the recoding strategy is needed first for the long term preservation of electronic recording data. Thus, without affecting data quality and deformation of optical discs, the choice of optimal disc and drive in recoding data will be a solution for the long term preservation of recoding data.