• 기록학연구
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• 제16호
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• pp.3-37
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• 2007

전자기록의 생산이 보편화되어가면서 종이기록 중심의 기록관리는 많은 변화를 요구받고 있다. 전자기록의 내용 맥락 구조정보를 어느 시점에 어떠한 방법으로 확보하여 기록의 증거성 진본성 신뢰성을 보존할 것인가가 기록관리에 있어서 주요한 이슈로 제기되고 있으며, 이러한 논의의 중심에 기록관리 메타데이터가 있다. 이 글은 기록관리 라이프사이클 중 현용 준현용 단계에서 요구되는 기록관리 메타데이터를 정립하는데 목적이 있다. 현용 준현용 단계에 주목하는 이유는 기록의 진본성을 '업무활동의 증거'라는 측면에서 이해하고자 하는 것과 관련이 있다. 기록이 업무맥락 가운데서 생산되고 관리의 영역으로 획득되는 시기가 현용과 준현용 단계이며, 이때 기록의 진본성을 획득하고 유지시키는데 중요한 역할을 하는 것이 기록관리 메타데이터이기 때문이다. 이 글에서는 기록관리 메타데이터를 체계적으로 설계하기 위한 방법으로서, 기록의 생산에 관여하는 엔티티간의 관계를 규명하고 이를 설명하기 위한 데이터 모델의 수립을 통하여 메타데이터 요소를 제안하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 B
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• pp.1239-1241
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• 2004

In this paper, electronic ballast with Interleaved Boost Cell is presented. The proposed topology is based on a single-stage ballast which combines a boost converter and a half-bridge series resonant inverter High power factor and low THD(reduction of current ripple) are achieved by using the boost semi-stage operating in discontinuous conduction mode, and inverter semi-stage operated above resonant frequency to provide zero voltage switching is employed to ballast the fluorescent lamp. The experimental results from the ballast system with fluorescent lamps have demonstrated the feasibility of the proposed electronic ballast.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1999년도 전력전자학술대회 논문집
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• pp.319-322
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• 1999

This paper presents a novel single-stage Power Factor Corrected(PFC) AC/DC forward converter with semi-automatic current shaping in order to achieve the unity power factor and an isolated output. Since the proposed circuit is combined a boost converter used for PFCs with a forward converter used for DC to DC conversion, the over-all size of system could be reduced. And thanks to the zero voltage switching(ZVS) in both switches, the voltage stress can be reduced considerably. A simple auxiliary circuit adopted into the secondary of transformer is composed of lossless components for reducing surge voltage. A prototype which has tow IGBT(Insulated Gate Bypolar Transistor) modules as switching device is manufactured to evaluate the proposed topology. The characteristics of the proposed circuit are tested, and the validity is verified by experimental results.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 추계학술대회 논문집 학회본부
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• pp.456-458
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• 1997

The phase-lock technique is applied to a three-phase semi-bridge type battery charger system. Using an inner fast dynamic loop, the phase-locked voltage control (PLVC) technique of three-phase semi-bridge converter is proposed to give a frequency synchronism and to reduce the subharmonics due to the unbalance of transformer or power line. To protect the power devices, the two stage soft-start, function with softly locking the phase and softly increasing the current is presented. As limiting the reference voltage of the inner voltage control loop, muti-lock phenomena are removed on the PLVC loop. A current limit function is also proposed to limit the current of battery and converter. The proposed controller is confirmed through experiment results.

• 한국문헌정보학회지
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• 제37권2호
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• pp.187-205
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• 2003

본 연구는 기록물관리법에 규정된 자료관의 업무분석을 통해 한국 자료관의 특징과 발전방향에 대해 논의한 것이다. 법에서 규정하고 있는 자료관의 업무는 기본적인 기록물관리 영역, 일반 간행물 및 도서관리 영역, 기타 각종 관리 영역의 업무가 포함된다. 업무영역 분석 결과, 한국의 자료관은 기록물의 계통별 관리, 통합된 기록물관리시스템의 지향, 생산단계로부터의 조정$\cdot$감독기능의 강화, 증거성 및 안정성 보호의 중시, 기록물의 분산보존, 기록물 이용촉진 등에 기여하였다. 자료관의 발전 방향으로 자료관 업무 내용$\cdot$절차$\cdot$방법의 상세화, 전문요원 배치의 보장, 이상적인 자료관 모델의 수립, 문헌정보학계와의 협력 강화, 지역정보센터로의 발전모색, 융통성 있는 자료관 설치, 공공기관의 법규이행에 대한 의지 고양 등을 제시하였다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2018년도 추계학술대회
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• pp.59-61
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• 2018

본 논문에서는 입력전류를 센싱 받지 않아도 역률 보상을 하는 새로운 단일단 브리지리스 AC-DC컨버터를 제안한다. 제안하는 컨버터의 스위치는 전구간에서 ZVS(Zero Voltage Switching) 턴 온을 성취하며, 다이오드는 전구간에서 ZCS(Zero Current Switching) 턴 오프를 성취한다. 제안하는 컨버터의 넓은 범위의 출력전압 제어와 간단한 전력 제어를 위해 SDAB(Semi-Dual Active Bridge)기반의 모듈레이션 기법을 적용하였다. 1kW급 50kHz의 스위칭 주파수를 갖는 시작품을 통해 본 논문의 타당성을 검증하였다.

• Journal of Power Electronics
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• 제13권4호
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• pp.592-599
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• 2013

This paper investigates a new isolated single-phase AC-DC converter, which integrates a modified AC-DC buck-boost converter with a DC-DC forward converter. The front semi-stage is operated in discontinuous conduction mode (DCM) to achieve an almost unity power factor and a low total harmonic distortion of the input current. The rear semi-stage is used for step-down voltage conversion and electrical isolation. The front semi-stage uses a coupled inductor with the same winding-turn in the primary and secondary sides, which is charged in series during the switch-on period and is discharged in parallel during the switch-off period. The discharging time can be shortened. In other words, the duty ratio can be extended. This semi-stage can be operated in a larger duty-ratio range than the conventional AC-DC buck-boost converter for DCM operation. Therefore, the proposed converter is suitable for universal input voltage (90~264 $V_{rms}$) and a wide output-power range. Moreover, the voltage stress on the DC-link capacitor is low. Finally, a prototype circuit is implemented to verify the performance of the proposed converter.

• 대한조선학회지
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• 제23권4호
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• pp.25-34
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• 1986

A two-dimensional linear method has been developed for the motion and the second-order steady force arising from the hydrodynamic coupling between waves and currents in the presence of a body of arbitrary shape. Interaction between the incident wave and current in the absence of the body lies in the realm beyond our interest. A Fredholm integral equation of the second kind is employed in association with the Haskind's potential for a steadily moving source of pulsating strength located in or below the free surface. The numerical calculations at the preliminary stage showed a significant fluctuation of the hydrodynamic forces on the surface-piercing body. The problem is approximately solved by using the asymptotic Green function for $U^2{\rightarrow}0$. The original Green function, however, is applied for the fully submerged body. Numerical calculations are made for a submerged and for a half-immersed circular cylinder and extensively for the mid-ship section of a Lewis-form. Some of the results are compared with other analytical results without any available experimental data. The current has strong influence on roll motion near resonance. When the current opposes the waves, the roll response are generally negligible in the low frequency region. The current has strong influence on roll motion near resonance. When the current opposes the wave, the roll response decreases. When the current and wave come from the same direction, the roll response increases significantly, as the current speed increases. The mean drift forces and moment on the submerged body are more affected by current than those on the semi-immersed circular cylinder or on the ship-like section in the encounter frequency domain.

• 기록학연구
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• 제6호
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• pp.41-72
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• 2002

Electronic environment affects archival community to a great extent. It redefines virtually every stage of archival management form creation to current and semi-current use, to appraisal, and to preservation of records. Faced with the problems caused by ever increasing electronic records, the community is forced to reconsider traditional concepts, approaches, methodologies, even the basic paradigm embedded in archival theory and practice. The present paper discusses the need to reexamine principles and techniques of archival management in the light of digital environment. It also urges archives and archival institutions, the archival profession, or the archival community at large, to participate in this critical enterprise. Success in this endeavor will, eventually, pave the road toward creating, organizing, providing access to, preserving reliably and authentically electronic records and designing proper system for the societal collective memory in recorded digital information.

• 한국해양공학회지
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• 제15권4호
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• pp.34-45
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• 2001

In the persent study, we conducted numerical experiments using a three-dimensional baroclinic equation model and a Lagrangian method for clarifying the hydrodynamics in Osaka Bay under the yearly mean discharge and visualizing the behaviour of particles of different settling velocity discharged from Yodo River and sedimentation pattern on the sea bottom. Particles are transported from the Yodo River to the south direction by the residual circulation of the bay head at the first stage, and after most of suspended solids particles are settled down at any layer and returned in the south-east coastal area through bottom layers by an estuarine circulation. The results show that estuarine circulation plays an important part of suspended solids transportation in the Osaka Bay.