• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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• pp.935-938
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• 2004

We have studied several light guide concepts for light-valve projection engines. The aim of the light guide is to replace the array of lenses and mirrors in conventional transmission-type projection engines. Volume, cost and weight can be reduced, at a similar or better performance level. Results of a first prototype are discussed.

• 오토저널
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• 제18권1호
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• pp.2-15
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• 1996

• 전자통신동향분석
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• 제37권3호
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• pp.11-22
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• 2022

The development and application of silicon photonics technology to terabit optical transmission are expected in the future. Silicon photonics technology is recognized as the only technology focusing on increasing the bandwidth of data center switches. High-density integration-based small optical subassemblies, optical engines, and optical transceivers are converged with the silicon photonics technology to accelerate a revolution in optical interfaces.

• 전기전자학회논문지
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• 제24권4호
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• pp.1086-1092
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• 2020

일상 환경에서 동작하는 자율 에이전트를 구현하기 위해서는 이미지나 객체에 존재하는 텍스트를 인식하는 기능이 필수적이다. 주어진 이미지에 입력 변환, 특성 인식, 워드 예측을 적용하여 인식된 텍스트에 존재하는 워드를 출력하는 과정에 다양한 딥러닝 모델이 활용되고 있으며, 딥뉴럴넷의 놀라운 객체 인식 능력으로 인식 성능이 매우 향상되었지만 실제 환경에 적용하기에는 아직 부족한 점이 많다. 본 논문에서는 인식 성능 향상을 위하여 텍스트 존재 영역 감지, 텍스트 인식, 워드 예측의 파이프라인에 OCR 엔진과 분류기로 구성된 애드온을 추가하여 기존 파이프라인이 인식하지 못한 텍스트의 인식을 시도하는 접근법을 제안한다. IC13, IC15의 데이터 셋에 제안 방법을 적용한 결과, 문자 단위에서 기존 파이프라인이 인식하는데 실패한 문자의 최대 10.92%를 인식함을 확인하였다.

• 대한기계학회논문집B
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• 제27권10호
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• pp.1370-1376
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• 2003

The investigation of liquid fuel film on the cylinder liner is an essential to understand the engine-out hydrocarbon emissions formation in SI engines. In this research, two-dimensional visualization was carried out to investigate the liquid fuel film on the quartz liner in the optical engine. For this, the optical engine with hydraulic system was designed based on the commercial SI engine. The visualization was based on the laser-induced fluorescence with total reflection technique. Using a quartz liner and a special lens, only the liquid fuel film on the liner was visualized. With using this technique, the distribution of the fuel film on the cylinder liner was measured for different engine conditions and injection timing in the optical engine.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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• pp.947-950
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• 2004

The discusses of this study is that we combined the systems with a new type of LCOS optical engine and the latest color management of LMS to measure the distribution of illuminance, chromaticity and Contrast on the big size of the screen and we will focus on the distribution of temperature at the surface of the PS converter under the heat to evaluate the effectiveness of the heat dissipated faculty of the optical engine system. It will support that we design and fabricate the optics devices and optical engines.

• 동력기계공학회지
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• 제21권3호
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• pp.12-18
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• 2017

Diesel and gasoline engines will be used as main power system of automobiles. Recently, engine downsizing is widely applied to both gasoline and diesel engines in order to improve fuel economy and exhaust emissions. Engine downsizing means small engine combustion chamber with higher combustion pressure. Therefore, spray and combustion process should be investigated under these high pressure and temperature conditions. In this study, constant volume combustion chamber which enables easy optical access from six directions was developed. Combustion chamber was designed to resist maximum pressure of 15 MPa and maximum temperature of 2,000 K. Combustible pre-mixed mixture was introduced into combustion chamber and ignited by spark plugs. High pressure and temperature were implemented by combustion of pre-mixed mixture. Three initial conditions of different pressure and density were tested. High repeatability of combustion process was implemented which was proven by low standard deviation of combustion pressure.

• 오토저널
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• 제7권2호
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• pp.55-63
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• 1985

This study is focused on deposition process leading to inefficiency and hot corrosion in fossil fuel-fired furnaces and engines. An improved understanding of the coupled thermodynamics, kinetics, and transport processes governing the deposition rate of inorganic oxides and salts from hot gases containing these compounds can suggest more efficient test strategies and control measures. Accordingly, an optical re-evaporation method for accurately measuring the growth rate of deposits under laboratory burner conditions has been developed. To demonstrate the technique and provide data suitable for theoretical model development, a deliberately simple chemical system and target geometry are used. Potassium sulfate(K$_{2}$SO$_{4}$)is introduced into a premixed propane-air flat flame at atmospheric pressure. The growth rate of $K_{2}$SO$_{4}$ on an electrically heated Pt ribbon is measured by re-evaporation technique.

• 한국분무공학회지
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• 제25권2호
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• pp.60-67
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• 2020

Despite its benefit in engine thermal efficiency, gasoline-direct-injection (GDI) engines generate substantial particulate matter (PM) emissions compared to conventional port-fuel-injection (PFI) engines. One of the reasons for this is that the spray collapse caused by the spray-to-spray interaction forms the locally rich fuel-air mixture and increases the fuel wall film. Previous studies have investigated the spray collapse phenomenon through the macroscopic observation of spray behavior using laser optical techniques, but it is somewhat difficult to understand the interaction between sprays that is initiated in the near-nozzle region within 10 mm from the nozzle exit. In this study, the spray structure, droplet size and velocity data were obtained using an X-ray imaging technique from the near-nozzle to the downstream of the spray to investigate the spray-to-spray interaction and discuss the effects of spray collapse on local droplet size and velocity distribution. It was found that as the ambient density increases, the spray collapse was promoted due to the intensified spray-to-spray interaction, thereby increasing the local droplet size and velocity from the near-nozzle region as a result of droplet collision/coalescence.

• 한국분무공학회지
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• 제12권4호
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• pp.211-219
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• 2007

The liquid film thickness inside a pressure-swirl nozzle was measured, and then the measured liquid film thickness was compared with the results from previous empirical equations. The liquid film inside the nozzle was visualized using extended transparent nozzles and a microscopic imaging system, and then the measurement error was evaluated using optical geometry analysis. The high injection pressures up to 7MPa were adopted to simulate the injection conditions of the direct-injection spark-ignition engines. The totally different two injectors with different fuels, nozzle lengths, nozzle diameters and swirlers were utilized to obtain the comprehensive equations. The results showed that the liquid film thickness very slightly decreased at high injection pressures and the empirical equations overestimated the effect of injection pressure. Most of empirical equations did not include the effect of nozzle length and swirler angle, although it caused significant change in liquid film thickness. A new empirical equation was suggested based on the experimental results with the effects of fuel properties, injection pressure, nozzle diameter, nozzle length and swirler angle.