• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제5권6호
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• pp.674-685
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• 1999

MIDAS-II는 한국전자통신연구원에서 개발한 바다 DBMS의 저장 시스템이다. MIDAS-II 볼륨은 데이터의 논리적 저장 단위인 파일을 저장하는 영역을 가리킨다. 본 논문에서는, MIDAS-II가 대용량 멀티미디어 데이터 서버의 저장 시스템으로 기능하도록 광 디스크 쥬크박스 또는 테이프 라이브러리와 같이 복수 개의 저장 매체 (platter , 예를 들어 디스크 또는 카트리지 테이프)로 구성된 Tera 바이트 급의 3창 저장 장치를 장착할 경우 이를 위한 볼륨 구조의 설계 및 구현에 대해 기술한다. 본 논문에서 제안하는 볼륨 구조는 3차 저장 장치 접근 시 성능 제고를 위하여 디스크 캐쉬 영역을 두고 있으며, 3차 저장 장치의 저장 매체별 관리 기능을 제공한다. Abstract MIDAS-II is the storage systemfor BADA DBMS developed at ETRI. A volume of MIDAS-II is the area where the files, the logical unit for storing data, are stored. This paaper describes the design and implementation of a new MIDAS-II volume structure for the tertiary storage device such as an optical disk juke box or a tape library equipped with multiple platters(disks or cartridge tapes, for example ). Incorporating thetertirary storage device of the order of tera bytes into MIDAS-II enables it to function as a storage system for a massive amount fo multimedia eata server. The volume structure for the tertiary storage device proposed in this paper features disk caching for performing improvement and direct control of theindividual platter.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
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• pp.205-206
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• 2005

PRAM (Phase change Random Access Memory) is one of the most promising candidates for next generation Non-volatile Memories. The Phase change material has been researched in the field of optical data storage media. Among the phase change materials, $Ge_2Sb_2Te_5$(GST) is very well known for its high optical contrast in the state of amorphous and crystalline. However, the characteristics required in solid state memory are quite different from optical ones. In this study, the structural properties of GST thin films with bottom electrode were investigated for PRAM. The 100-nm thick GST films were deposited on TiN/Si and TiAlN/Si substrates by RF sputtering system. In order to characterize the crystal structure and morphology of these films, we performed x-ray diffraction (XRD) and atomic force microscopy (AFM).

• 한국광학회:학술대회논문집
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• 한국광학회 2006년도 하계학술발표회 논문집
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• pp.39-40
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• 2006

Digital image-projection and several modifications are the classical applications of Digital Micromirror Devices (DMD), however further applications in the field of optical metrology are also available. Operated with certain patterns, a DMD can function, for instance, as an array of pinholes that may substitute the Galvanic mirror or the stage scanning system presently used for 2 dimensional scanning in confocal microscopes. The various process parameters that influence the result of measurement (e.g. pinhole size, lateral scanning pitch and the number of pinholes used simultaneously, etc.) should be configured precisely for individual measurements by appropriately operating the DMD. This paper presents suitable conditions for the diffraction limited analysis between DMD-optics-CCD to achieve the best performance. Also sampling theorem that is necessary for the image acquisition by scanning system is simulated with OPTISCAN which is the simulator based on the diffraction theory.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 1999년도 가을 학술발표논문집 Vol.26 No.2 (3)
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• pp.69-71
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• 1999

본 논문에서는 대용량 데이터의 계층적 자료저장을 위한 광주크박스 관리 시스템을 설계하고 구현한다. 광주크박스를 이용한 계층적 자료저장을 함으로써 적은 비용으로 대용량의 저장공간을 확보하며, 적절한 스케쥴링 정책에 의해 효과적인 자료 관리를 할 수 있다. 관리 시스템은 사용자와의 인터페이스를 위한 부분. 미디어의 관리를 위한 부분, 주크박스를 제어하기 위한 부분으로 구성된다. 각 구현 모듈들은 운영체제 독립적으로 설계되어 재사용이 가능하며 다양한 운영체제에 적용할 수 있다.

• 정보저장시스템학회논문집
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• 제1권1호
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• pp.34-41
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• 2005

We report some recent results in the rewritable Blu-ray Disc with enhanced overwrite cyclability by using the growth dominant eutectic based Ge(Sb70Te30)+Sb recording layer, GeN interface layer and write strategy optimization. We have developed phase-change optical media with appropriate write strategy for 36(i.e., 1X)-72Mbps(i.e., 2X) dual speed Blu-ray Disc system and fur the future high speed optical data storage. For recording layer, eutectic-based Ge(Sb70Te30)+Sb material was used and Sb/Te ratio and Ge content were optimized to obtain proper erasability and archival stability of recorded amorphous marks. The recording layer is wrapped up in GeN interface layers to obtain overwrite cyclability and higher crystallization speed. In addition, we designed appropriate write strategy so called Time-Shifted Multipulse (TSMP) write strategy where starting position of multipulse parts are shined from reference clock. With this write strategy, the jitter characteristics of the disc was improved and we found that leading edge jitter was improved much more than trailing edge jitter in 1X-2X speed recording. Finally, we investigated the higher speed feasibility of 144Mbps(i.e., 4X) by adopting some elemental doping to the eutectic based Ag-In-Sb-Te recording layer and structural optimization of constitution layers in Blu-ray Disc. In the paper, we report the effect of Sn addition for the feasibility of higher speed recording. The addition of Sn shows increases of the crystallization speed of phase change recording layer.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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• pp.509-511
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• 2005

KOMPSAT -2 equipped with an optical telescope(MSC) will be launched in this year. It can take images of the earth with push-broom scanning at altitude 685Km. Its resolution is 1m in panchromatic channel with a swath width of 15 km After the MSC is tested and the performance is measured at instrument level, it is installed on satellite. The image passes through the electro-optical system, compression and storage unit and fmally downlink sub-systems. This integration procedure necessitates the functional test of all subsystems participating in the image chain. The objective of functional test at satellite level(Quick Look test) is to check the functionality of image chain by real target image. Collimated moving image is input to the EOS in order to simulate the operational environments as if KOMPSAT -2 is being operated in orbit. The image chain from EOS to data downlink subsystem will be verified through Quick Look test. This paper explains the Quick Look test of KOMPSAT -2 and compares the taken images with collimated input ones.

• 대한원격탐사학회지
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• 제18권1호
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• pp.61-69
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• 2002

The purpose of Electro-Optical Camera (EOC), the primary payload of KOMPSAT-1, is to collect high resolution visible imagery of the Earth including Korean Peninsula. EOC images will be distributed to the public or many user groups including government, public corporations, academic or research institutes. KARI will offer the online service to the users through internet. Some application, e.g., generation of Digital Elevation Model (DEM), needs a secondary data such as satellite ephemeris data, attitude data to process the EOC imagery. EOC imagery with these ancillary information will be distributed in a file of Hierarchical Data Format (HDF) file formal. HDF is a physical file format that allows storage of many different types of scientific data including images, multidimensional data arrays, record oriented data, and point data. By the lack of public domain softwares supporting HDF file format, many public users may not access EOC data without difficulty. The purpose of this research is to develop a browsing system of EOC data for the general users not only for scientists who are the main users of HDF. The system is PC-based and huts user-friendly interface.

• 한국광학회:학술대회논문집
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• 한국광학회 2001년도 제12회 정기총회 및 01년도 동계학술발표회
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• pp.58-59
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• 2001

최근 홀로그래픽 데이터 저장 국제 워크샵(International Workshop on Holographic Data Storage)에서 발표된 자료에 따르면 광메모리 데모 시스템들의 저장 용량이 100MB~150GB에 달하고 있으며, page당 용량은 1백만 비트(1000$\times$1000 bits)이상, 데이터 전송 속도는 1Gbit/sec에 이르고 있다. 반면에 현재까지는 상용화 단계의 시스템은 발표되지 않고 있다. 본 논문에서는 이들 시스템과 성능 차이는 많이 나지만 그 동안의 광굴절 결정의 특성 실험결과와 각각의 광학 시스템의 연구 결과들을 토대로 디지털 데이터를 기록하고 재생할 수 있는 초기 자동화된 데모 시스템을 구현하였다. (중략)

• 한국연소학회:학술대회논문집
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• 한국연소학회 제26회 KOSCO SYMPOSIUM 논문집
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• pp.75-83
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• 2003

Diode laser absorption system is advantageous of their non-invasive nature, fast response time, high sensitivity and real-time measurement capability. Furthermore, recent advances in room-temperature, near-IR and visible diode laser sources for telecommunication, optical data storage applications are enabling combustion diagnostics system based on diode laser absorption spectroscopy. So, combined with fiber-optics and high sensitive detection strategies, compact and portable sensor system are now appearing for a variety of applications. The objective of this research is to take advantage of distributed feed-back diode laser and develope new gas sensing system. It experimentally found out that the wavelength, power characteristics as a function of injection current and temperature. In addition to direct absorption and wavelength modulation spectroscopy have been demonstrated in these experiments and have a bright prospect to this diode laser system.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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• pp.478-481
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• 2005

The PMU (Payload Management Unit) is the main subsystem for the management, control and power supply of the MSC (Multi-Spectral Camera) Payload operation. It is the most important function for the electro-optical camera system that performs the Non-Uniformity Correction (NUC) function of the raw imagery data, rearranges the data from the CCD (Charge Coupled Device) detector and output it to the Data Compression and Storage Unit (DCSU). The NUC board in PMU performs it. In this paper, the NUC board system is described in terms of the configuration and the function, the efficiency for non-uniformity correction, and the influence of the data compression upon the peculiar feature of the CCD pixel. The NUC board is an image-processing unit within the PMU that receives video data from the CEV (Camera Electronic Unit) boards via a hotlinkand performs non-uniformity corrections upon the pixels according to commands received from the SBC (Single Board Computer) in the PMU. The lossy compression in DCSU needs the NUC in on-orbit condition.