• 전기전자학회논문지
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• 제15권1호
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• pp.70-75
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• 2011

Longitudinal recording has been the cornerstone of all two generations of magnetic recording systems, FDD and HDD. In recent, perpendicular recording has received much attention as promising technology for future high-density recording system Research into signal processing techniques is paramount for the issued storage system and is indispensable like longitudinal recording systems. This paper focuses on the performance evaluation of the various detectors under perpendicular recording system. Parameters for improving the their performance are examined for some detectors. Detectors considered in this work are the partial response maximum likelihood (PRML), noise-predictive maximum likelihood (NPML), fixed delay tree search with decision feedback (FDTS/DF), dual decision feedback equalizer (DDFE) and multilevel decision feedback equalizer (MDFE). Their performances are analyzed in terms of mean squared error (MSE) and noise power spectra, and similarity between recording channel and partial response (PR) channel.

• 한국산업정보학회논문지
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• 제13권2호
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• pp.88-99
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• 2008

본 논문에서는 ERP를 도입하여 개발중인 국방인사정보체계에서 구현되어야 할 인사기록방법을 절차에 중점을 두고 제안한다. 국방부와 육 해 공군이 공동으로 인사업무에서 사용할 수 있는 인사기록절차는 현재 국방부와 각 군 인사기록절차의 문제점인 수작업과 전산작업의 혼용, 일부기관(국방부)의 전자적 기록관리 부재, 실시간 기록미흡, 기록사항의 확인 및 입력 중앙집중/업무과다를 해결할 수 있도록 제안되었다. 인사기록절차는 표준화된 인사기록 절차도와 인사기록절차 정의서로 표현되었다. 제안된 인사기록절차는 인사기록의 진본성, 무결성, 신뢰성, 이용가능성이 보장되도록 세 가지의 개선방향인 일원화된 전자기록관리, 실시간 기록관리, 검증권한의 효율적 집중과 분산을 적용하여 제안되었으며 제안된 인사기록절차가 개발중인 국방인사정보체계를 통해서 구현될 시 12개의 기록관리체계의 통합, 기록관리시간을 45일에서 3일로 감소, 검증권한을 국방부 및 각 군 본부와 소속기관 및 개인으로 분산, 일부 수작업문서의 감소효과를 가져올 수 있다.

• 정보저장시스템학회논문집
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• 제5권2호
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• pp.64-69
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• 2009

In this paper, we investigate field distribution and interference pattern in the exit pupil and in the focal region. Also, we compare with metal and dielectric substrate for near-field recording. To obtain field distribution, we use modified vector diffraction theory and Zernike Polynomials. Finally, we design and optimize refractive index and thickness of disk for near-field surface recording and cover-layer incident recording.

• 한국항행학회논문지
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• 제28권1호
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• pp.77-86
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• 2024

'UAS 비행 기록 시스템'은 다양한 구성 요소로 이루어진 무인항공기 시스템에 장착되어 비행 관련 데이터를 기록하는 시스템이다. 이 시스템이 기록한 데이터는 유사사고 예방을 위하여 항공사고 및 준사고 조사에 활용되어야 한다. 특히, 운용 위험도가 높은 무인항공기 시스템의 범주에 대해서는 유인항공기의 안전장치 수준에 근접하게, 감항성 확보를 위하여 무인항공기 시스템 특성을 반영한 비행 기록 시스템의 개발이 시급하다. 본 논문은 항공사고 및 준사고 조사를 위해 UAS 비행 기록 시스템의 필요성을 부각하고, 운용 위험도가 큰 'Certified Category'를 대상으로 비행 기록 시스템 파라미터 도출 방안을 모색하였다. 이를 위해 Inter-City UAM을 구체적인 사용 사례로 지정하고, 임무 프로파일 및 시나리오로부터 사고 발생과 위해요인을 상정하여 시스템 파라미터 도출에 접근하는 프로세스를 고안하였다. 연구 결과, 이 프로세스를 통해 파라미터 도출이 가능함을 확인하였다.

• 정보저장시스템학회논문집
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• 제4권1호
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• pp.19-22
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• 2008

For the assembly and evaluation of solid immersion lens (SIL) optical head which is the key component of SIL based near field recording (NFR) technology, we modify the Twyman-Green interferometer. Super-hemisphere SIL optical head for the surface recording is assembled and evaluated by the modified Twyman-Green interferometer. In order to verify the optical performance of the assembled SIL optical head, we compare the measured results of the SIL optical head with the simulation ones. Finally, we show the feasibility of applying the assembled SIL optical head to near field recording system by the experiment of the dynamic gap control based on test bed.

• 정보저장시스템학회논문집
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• 제2권4호
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• pp.219-223
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• 2006

Near field recording(NFR) technology has been considered as a strong candidate to surpass the far-field diffraction limit imposed by the nature of light in present optical disk drives such as CD, DVD, and BD(Blu-ray Disk). In this paper, we suggest novel inside near-field dual layer recording concept using elliptic shape solid immersion lens(ESIL).

• 정보저장시스템학회논문집
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• 제3권4호
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• pp.173-177
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• 2007

A photo-reactive methacrylate monomer having triazine as a core component was examined for photochromic diffractive image formation. Photochromic photopolymer films as a recording media contained a monomer mixture of triazine difunctional metharylate (DT) and ethylene glycol phenyl ether acrylate, binder polymer, photo initiator, and a photochromic spiro-oxazine dye. The content of photochromic dye was changed to examine the effect of photochromophore on diffraction efficiency and real holographic image formation. Holographic recording was performed on the photopolymer film by the combination of reference and probe beam. The diffraction efficiency of the photopolymer film in real-time measurement reached a maximum of $\sim90%$ within 30s. It was highly dependent on the photochromophore contents. After holographic recording, the color of the recorded area was changed under UV light (365 nm) and reversibly bleached to original color upon exposure to a visible light source. Films containing only photochromophore without monomer mixture were not reactive under the recording beam (491nm). Diffractive image formation and mechanism of the holographic recording in the presence of photochromophore will be presented.

• 정보저장시스템학회논문집
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• 제1권1호
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• pp.58-66
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• 2005

Pseudo-Near Field Recording (Pseudo-NFR) system is proposed to prevent contamination and oxidation of media surface occurred in conventional NFR systems. To solve these critical problems of the NFR systems, we investigate the optimal thickness of cover layer for Pseudo NFR. This paper presents the theoretical analysis for cover layer thickness based on the measured length of dust particle and numerical simulation for the temperature distribution using Finite Difference Time Domain (FDTD) method and heat conduction equation. To verify the simulation results, we conduct and compare simulation results in case of far field MO recording and near field MO recording. A measured dust particle length in general environment was mostly less than $20{\mu}m$, and the optimal thickness of cover layer is $30{\mu}m$ in this case. Based on the designed optimal cover layer thickness, temperature distribution is simulated to have $800{\~}850^{\circ}C$.

• 한국멀티미디어학회논문지
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• 제17권7호
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• pp.829-837
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• 2014

This paper develops an automatic go recording system based on image processing. We use Random Sample Consensus to detect the circular shape of stone and propose a set of methods to improve the computational overhead of RANSAC. The proposed scheme is not affected by the changes of stone location, illumination, and camera distance, which is different from existing methods. We implemented the proposed scheme into a working system and confirmed that the recording is feasible and the problems have been improved.

• 정보저장시스템학회논문집
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• 제1권1호
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• pp.48-52
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• 2005

The research topic of super-RENS technology is shifting from the signal intensity (CNR; Carrier to Noise Ratio) to the signal uniformity (Jitter or bER). To achieve an uniform signal characteristics, it is important to reduce signal fluctuation in a super-RENS disc. In this study, we investigated the relation between signal fluctuation and low frequency noise (LFN), and analyzed LFN increase in recording and readout processes. It was found that signal fluctuation had a close relationship with the LFN. Also, it was found that the recorded mark shape such a bubble type and high readout power increased the LFN in recording and readout process of a super-RENS disc. So, using non-bubble type recording material and low super-resolution readout material, we markedly improved the LFN in a super-RENS disc.