• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2005년도 추계종합학술대회
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• pp.889-892
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• 2005

본 논문에서는 VPN을 위한 IPSec 암호 프로세서의 설계 및 구현에 관하여 기술한다. IPSec 암호 프로세서의 기밀성 서비스를 위한 암호엔진은 DES, 3 DES, SEED, 그리고 AES 알고리듬 등을 사용하여 설계하였고, 인증 및 무결성 보안 서비스를 위한 인증엔진은 HMAC(The Hashed Message Authenticat ion Code)-SHA-1을 기본으로 설계하였다. 제안된 암호 프로세서는 Verilog를 사용하여 구조적 모델링을 행하였으며, Xilinx사의 ISE 6.2i 툴을 이용하여 논리 합성을 수행하였다. FPGA 구현을 위해서 Xilinx ISE 6.2i툴과 Modelsim을 이용하여 타이밍 시뮬레이션을 수행하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.1108_1109
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• 2009

본 논문은 계통연계형 열병합 발전의 동작특성을 시뮬레이션을 통해 분석하는데 목적이 있다. 계통연계형 열병합 발전은 가스엔진, 영구자석형 동기발전기, 전력변환기로 구성되어 있는 것을 모델링하였다. 본 연구에서는 가스엔진이 일정속도로 동작하고 다극형 영구자석형 발전기에서 생산되는 400Hz 출력을 컨버터와 인버터로 구성되어 있는 전력변환기를 통해 상용주파수의 교류로 전력계통과 연계하는 것을 모의 하였다. 시뮬레이션은 PSCAD/EMTDC 프로그램을 이용하였고 시뮬레이션모델을 통해 다양한 시뮬레이션을 수행하였다. 그리고 실제모델의 축소 모형을 설계하여 하드웨어 시뮬레이터를 제작하였다.

• 한국산업융합학회 논문집
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• 제5권2호
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• pp.119-126
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• 2002

In this study, general engine oil and the Miracle top engine oil of Dongjin chemistry company were tested to find the effects to the SI engine performance. Roller dynamometer used to find maximum power, fuel consumption rate and the emission. Maximum power was measured higher when the Miracle top engine oil was used in the vehicle. By use of the Miracle top engine oil, fuel consumption rate and emission was measured lower and compression pressure was higher compared use of general engine oil. Also the Miracle top engine oil was found to decrease the engine noise at the low RPM. And after 1,500km drive at the same condition, the dust in the oil pan and oil filter was measured less when the Miracle top engine oil used compared than general engine oil used.

• Tribology and Lubricants
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• 제29권2호
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• pp.77-84
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• 2013

A small engine-oil-deterioration detection sensor was developed and installed at the tip of a dipstick gage. The sensor part was manufactured using printed circuit board (PCB) manufacturing technology. A set of sensor covers was installed in order to protect the sensor and realize good signal stability. The small engine-oil-deterioration detection sensor system comprised a dual sensor having etched copper electrodes coated with gold and ceramic, a flexible PCB (FPCB) acting as electric wire, and a dummy PCB with only a lock connector. The sensor can easily be installed by insertion through the guide tube of a dipstick gage. Thus, a driver can easily handle it without further installation equipment. The sensor can determine the level of deterioration in the engine oil by estimating the corresponding dielectric constant of the engine oil.

• Tribology and Lubricants
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• 제17권3호
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• pp.198-208
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• 2001

A Parametric study based on a computer analysis of the lubrication system of a four-cylinder gasoline engine is illustrated. Through the parametric study, the effects of various aeration levels on the change of oil flow rate and pressure are investigated. Also, at high oil temperature and low engine speed, the effect of oil aeration level on oil flow characteristics in lubrication system is investigated. The illustrated results may give to designers the guide lines of oil aeration level for the safe design of engine lubrication systems in terms of minimum pressure at crank oil bore.

• 한국자동차공학회논문집
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• 제1권3호
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• pp.46-54
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• 1993

In order to develop a fuel-efficient gasoline engine oil, an experimental study was conducted using an engine dynamometer, a passenger car and the SRV machine. Oil samples with different viscosity were prepared by adding several friction modifiers to select the best one and also to investigate the effect of the viscosity grade. From the study, we have developed engine oils which result in good fuel economy. The viscosity grade of 7.5W/30 was best among the oils investigated with respect to fuel economy and a fatty amine type friction modifier had the good fuel-economy property.

• Tribology and Lubricants
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• 제29권3호
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• pp.143-148
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• 2013

In this study, several sensor parts used to obtain better signal stability are designed, a separate control circuit for the sensor is developed, and the results obtained using this control circuit are analyzed. The capacitances of the whole sensor system are measured using the control circuit connected to an improved flexible printed circuit board and an asymmetric dual sensor coated with a ceramic material. To realize good discrimination for a small change in the measured capacitance as the engine oil deteriorates, a commercial application-specific integrated circuit is installed on the control circuit as a capacitance-to-digital converter. The absolute error of a measured signal is found to be approximately ${\pm}4fF$.

• 드라이브 ㆍ 컨트롤
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• 제9권4호
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• pp.42-51
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• 2012

Variable displacement vane-type oil pumps represent one of the most innovative pump types for industrial applications, especially for engine lubrication systems. This paper deals with a modeling method for theoretical flow rate investigation of a typical variable displacement vane-type oil pump. This theoretical model is based on the pump geometric design and dynamic analyses. It can be considered as mandatory steps for a deeper understanding of the pump operation as well as for effectively implementing the pump control mechanisms to satisfy the urgent demands of engine lubrication systems. The developed pump model is finally illustrated by numerical simulations.

• 한국자동차공학회논문집
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• 제11권4호
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• pp.52-57
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• 2003

Common rail injection system is flexible in injection timing, injection duration and pressure in engine. Many researches have reported on the merits in the application of common rail systems. This research investigated on characteristics and performance for single cylinder diesel engine with a common .ail injection system by varying major parameters such as injection timing, injection duration and common rail pressure. The injection timing and injection duration were controlled by electronic pulse generated. and common rail pressure were controlled by PCV driver. The 498cc single cylinder diesel engine was used in this experiment. All data for combustion pressure, injection timing and injection duration were recorded by Labview. Furthermore, this test was focused on how to optimize injection conditions.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2010년도 한국컴퓨터종합학술대회논문집 Vol.37 No.1(C)
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• pp.540-544
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• 2010

모바일 환경에서 웹 브라우저 활용이 늘어나고 웹 페이지를 통한 다양한 서비스가 제공되면서 브라우저에서의 자바스크립트 성능이 중요한 요소가 되었다. 자바스크립트 엔진의 성능 개선을 위해 기존에 사용하던 인터프리터 대신에 머신 코드를 실행 시간에 생성하는 적시 컴파일러(JITC)가 도입되었다. 특히 모바일 환경에서 WebKit의 자바스크립트 엔진인 SquirrelFish Extreme(SFX)이 많이 사용되고 있다. 본 논문에서는 SFX의 성능 향상을 위하여 적시 컴파일러를 통해 생성된 머신 코드를 파일 시스템을 활용하여 파일에 저장하였다가 재사용하는 클라이언트 AOTC(ahead-of-time compilation) 방식을 제시하고 초기 실험 결과를 제시한다.