• 한국기계가공학회지
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• 제14권5호
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• pp.134-140
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• 2015

A control program of an engine control module (ECM) was developed, and its control performance was verified on a 750Ps marine diesel engine. The control method was designed for an engine rotational speed control system. For ECM hardware, the commercial rapid control prototype (RCP) ECM was used. The programming tool for control algorithm development was the MatLab/Simulink. The main control algorithm assembled many control models as engine cranking, run, and stall. Each model has sub-models to input/output control signals. The target engine speed was input signal from a speed control lever, and control output signal of the ECM was sent to the unit-injectors for fuel injection. The engine test was performed under various conditions of engine rotational speeds and dynamometer loads. The test results show that the control function of the ECM is suitable for electrical marine diesel engines.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2008년도 추계종합학술대회 B
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• pp.91-94
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• 2008

본 논문에서는 Full 하드웨어 기반 베이스라인 프로파일 레벨 3규격 H.264 인코더 코덱에서 사용할 수 있는 Direct Memory Access (DMA)를 설계하였다. 설계된 모듈은 CMOS Image Sensor(CIS)로부터 영상을 입력받아 메모리에 저장한 후 인코더 코덱 모듈의 동작에 맞춰 원영상과 참조영상을 각각 한 매크로블록씩 메모리에서 읽어 공급 또는 저장하며, 인코더는 한 매크로블록씩 처리하는데 660 cycle이 소요된다. 설계한 구조를 검증하기 위해 JM 9.4와 같은 reference Encoder C를 개발하였으며, Encoder C로부터 test vector를 추출하여 설계한 회로를 검증하였다.

• Smart Structures and Systems
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• 제30권2호
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• pp.159-172
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• 2022

To improve the accuracy of the standard penetration test (SPT) results, smart measurement system, which considers the energy transfer ratio into the sampler (ETR_Sampler), is required. The objective of this study is to evaluate the effects of joints and rod length on the transferred energy into the sampler. The energy transfer ratios into the rod head (ETR_Head) and ETR_Sampler, and the energy ratio from the head to the sampler (ER_HS) were obtained using energy modules, which were installed at the rod head and above the SPT sampler. Linear regression analyses are conducted to correlate the ER_HS with the number of joints, rod length, and SPT N-values. In addition, the dynamic resistances are calculated using both transferred energies into the rod head and into the sampler, and are compared with the corrected cone tip resistance measured from the cone penetration test (CPT). While the ETR_Head are generally constant, but the ETR_Sampler and ER_HS gradually decrease along the depth or the number of joints, except at certain depths with high SPT N-values. Thus, the ER_HS can be estimated using the number of joints, rod length, and SPT N-values. The dynamic resistance evaluated by E_Sampler produces a better correlation with the corrected cone tip resistance than that by E_Head. This study suggests that transferred energy into the SPT sampler may be effectively used for more accurate subsurface characterization.

• 한국광학회지
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• 제5권3호
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• pp.423-430
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• 1994

DFB-LD 칩으로부터 단일보드 광섬유 부착 2.5Gbps 광통신용 광원인 DFB-LD 모듈을 설계, 제작하였다. DFB-LD 모듈은 광 isolator가 삽입된 2 렌즈 quasi confocal 광학계로 구성된 원통형 서브 모듈과 14 pin butterfly 패키지가 분리된 구성으로서 이들 사이의 전기적 연결은 bias-T 회로가 형성된 하이브리드 기판으로 이루어지도록 설계하였다. 모듈 제작시 정밀한 부품 고정이 요구되는 서브 모듈 조립에는 레이저웰딩 방법을 사용하였다. 제작된 DFB-LD 모듈은 광결합 효율 20%, -3dB 소신호 변조 대역폭 2.6GHz 이상의 특성을 가졌으며 온도 순환검사에도 10% 이내의 광출력 변동만을 보임으로써 기계적 신뢰성을 확인할 수 있었다. 제작된 DFB-LD 모듈의 광송신 성능을 실제 2.5Gbps 광통신 시스템의 광원으로 적용하여 평가한 결과 47km의 광섬유 전송시 BER $1\times10^{-10}$ 조건에서 최대 -30.2dBm의 수신감도를 얻었으며 이 때 전송페널티는 소광비에 의한 것이 1.5dB, 분산에 의한 것이 1.0dB로 나타났다.

• 한국전기전자재료학회논문지
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• 제33권6호
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• pp.439-444
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• 2020

An increase in the temperature of photovoltaic (PV) modules causes reduced power output and shorter lifetime. Because of these characteristics, demands for the heat dissipation of PV modules are increasing. In this study, we attached a heat dissipation sheet to the back sheet of a shingled PV module and observed the temperature changes. The PV shingled module was tested under Standard Test Conditions (STCs; irradiance: 1,000 W/㎡, temperature: 25℃, air mass: 1.5) using a solar radiation tester, wherein the temperature of the PV module was measured by irradiating light for a certain duration. As a result, the temperature of the PV module with the heat dissipation sheet decreased by 3℃ compared to that without a heat dissipation sheet. This indicated that the power loss was caused by a temperature increase of the PV module. In addition, it was confirmed that the primary parameter contributing to the reduced PV module output power was the open circuit voltage (Voc).

• 전력전자학회:학술대회논문집
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• 전력전자학회 2018년도 추계학술대회
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• pp.163-164
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• 2018

본 논문에서는 새로운 MMC(Modular Multilevel Converter)용 SM(Sub-Module) 시험회로와 이를 제어하기 위한 제어기법을 제안한다. 계통연계형 MMC 시스템에서 한 상의 암(arm)에 흐르는 전류는 계통주파수의 2고조파 성분과 DC 전류를 포함하고 있다. 제안하는 시험회로는 암 전류를 선형적으로 근사화하고, 시험전류의 DC 성분을 제어하여 시험할 SM의 전압을 일정하게 유지한다. 시뮬레이션을 통해 제안하는 SM 시험회로와 제어의 타당성을 검증하였다.

• 천문학회보
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• 제45권1호
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• pp.70.3-70.3
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• 2020

Previous numerical simulations on planet-disk interactions revealed a lot of interesting phenomena including the planetary migration and the formation of many sub-structures inside the disks. However, these simulations were limited to an isothermal or adiabatic equation of state which does not account for various heating and cooling processes in the disks. Recent studies showed that the behavior of the planet-disk interaction can be significantly influenced by the disk thermodynamics. We develop a radiative diffusion module based on the two-temperature flux-limited diffusion approximation accounting for viscous heating and the accretion feedback. In this presentation, we describe our radiative diffusion solver, present some test results, and discuss potential applications of the module to planet-disk interactions,

• 천문학회보
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• 제37권2호
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• pp.209.2-209.2
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• 2012

UFFO Burst Alert & Trigger telescope (UBAT) is one of major instruments of UFFO-Pathfinder. The UBAT aims at 10 arcmin resolution localization of Gamma Ray Bursts with X-ray coded mask technique. It has $400mm{\times}400mm$ coded mask aperture, hopper, shielding and detector module with effective area of $191cm^2$. The detector module consists of an assembly of 36 64-ch MAPMTs and $25mm{\times}25mm$ pixellated YSO crystal array, and associated analog and digital electronics of about 2500 channels. We performed a vibration test using a dummy MAPMT with the detector module structure to measure the indused stress applied onto the MAPMT. We designed a sub-structure on the detector module to avoid the resonance that would otherwise deforms the detector module structure. A finite element analysis confirms the reduction of the load acceleration down to 12g. The experimental results are to be reported. Consequently, it proves that the MAPMT arrays of the flight UBAT detector module structure would survive in the space launch environment.

• 한국통신학회논문지
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• 제27권2C호
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• pp.143-149
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• 2002

시스템의 대규모, 복잡화는 시스템의 결함 여부를 테스트하는 것을 어렵게 하고 있다. 시스템의 구성은 기능별 모듈로 나눌 수 있으며, 시스템의 각 모듈이 전체 시스템의 신뢰도에 미치는 영향의 효율적인 분석을 통해 시스템 전체에 대한 효율적인 테스트 전략을 수립할 수 있고 이는 전체 시스템 테스트의 효율을 증대시킬 수 있을 것이다. 또한 시스템 모델을 정형화된 모듈로 나타낼 경우 그 시스템의 동작상의 논리적인 정확성, 성능분석 및 신뢰성 예측 등의 여러 특성 등의 효율적인 분석이 가능하다. 본 논문에서는 시스템 모듈을 그래프 모델로 정형화하고, 이것의 시스템 동작 특성을 기반으로 한 분석을 통하여 각 모듈이 전체 시스템의 신뢰성에 미치는 영향을 분석하는 기법을 제안한다.

• 설비공학논문집
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• 제23권8호
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• pp.549-555
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• 2011

For a $CO_2$ one-stage twin rotary compressor, a T-shaped suction port was used to effectively supply the suction gas stream into two individual suction chambers of the twin cylinders. Suction gas pulsations were observed in the pressure sensor signals and these were simulated by using the acoustic modeling of Helmholz resonators in parallel. The module of acoustic modeling was combined to a computer simulation program for the compressor performance. Validation of the simulation program has been carried out for a bench model compressor in a compressor calorimeter. Cooling capacity and the compressor input power were reasonably well compared between the simulation and the calorimeter test. Particularly, good agreement on P-V diagram between the simulation and the test was obtained.