• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.2
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• pp.500-510
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• 1996

This paper presents a new prototype of an engine mount for a passenger vehicle featuring ER(elector-rheological) fluids and piezoactuators. Conventional rubber mounts and various types of passive or semi-active hydraulic engine mounts have their own functional aims on the limited frequency band in the board engine operating frequency range. However, the proposed engine mount covers all frequency range of the engine operation. A mathematical model of the proposed engine mount is derived using the bond graph method which is inherently domain, the ER fluid is activated upon imposing electric field for vibration isolation while the piezoactuator. Computer control electric fluid for the ER fluid H.inf. cotrol technique is adopted for the piezoactuator. Computer simulation is undertaken in order to demonstrate isolation efficiency of the engine mount over wide operating frequency range.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.491-494
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• 2010

This paper describes the characteristics of Permanent Magnet Generator(PMG) and Homo-Polar Gnerator(HPG) applied in small aircraft engine. PMG has a advantage of miniaturization and fast bandwidth if it is using the DC/DC converter for power conversion which increases a volume and cost although. On the other hand, HPG has a advantage of simple voltage control accomplished by flux control of field coil. Recently, it is recommended the PMG without DC/DC converter module by reason of the wide range of input voltage of electronic loads and system efficiency.

• Journal of ILASS-Korea
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• v.26 no.3
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• pp.135-141
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• 2021

High-efficient HEV Engine cooling systems reflects variable coolant temperature because it can decrease the hydrodynamic frictional losses of lubricated engine parts in light duty conditions. In order to safely raise the operating temperature of passenger cars to a constant higher level, and thus optimize combustion and all accompanying factors, a new thermostat technology was developed : the electronically map-controlled thermostat. In this work, various crystalline plastics such as polyphthalamide (PPA) and polyphenylenesulfide (PPS) mixed with various glass fiber amounts were introduced into plastic fittings of automotive electronic controlled thermostat for the purpose of suppressing influx of coolant into the element and undesirable opening during hot soaking. Skirt was installed around element frame of automotive electronic controlled thermostat for improving thermal sensitivity in terms of response time, hysteresis and melting temperature. To validate the effectiveness and optimum shape of skirt, thermal sensitivity test and three-dimensional CFD simulation have been performed. As a consequence, important improvement in thermal sensitivity with less than 3℃ of maximum coolant temperature between opening and engine inlet was obtained.

• Proceedings of the KSME Conference
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• 2001.11b
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• pp.788-793
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• 2001

Test experience with a micro-turbine jet engine is introduced. The engine provides us with valuable opportunities to experience know-hows essential for engine development. It consists of a single radial compressor and a single stage turbine. Engine starting procedure has been established after many trials and errors. Static and dynamic engine performance tests were conducted. Static performance was found to be inferior to that advertised by the manufacturer. Further improvement is needed. Dynamic performance revealed that engine thrust overshoots unfavorably for the purpose of UAV control.

• Proceedings of the KIPE Conference
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• 2014.07a
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• pp.21-22
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• 2014

대형 상용차량을 위한 냉난방장치는 이동 또는 정차 중에도 일정 온도를 유지 시켜야한다. 종전의 상용차량의 냉동시스템은 엔진과 연계하여 압축기를 구동하거나 엔진과 연계된 발전기의 전력을 이용하여 온도를 유지하였다. 이러한 방식은 제어가 용이하지 않고 효율성이 낮은 단점을 가지고 있다. 본 논문에서는 이러한 단점을 개선하고자 대형 상용차량이 정차중인 무시동 기간에도 일정 온도를 유지 할 수 있도록 직렬 L-C 공진을 이용한 2.5kW급 DC-DC 컨버터를 제안 하였다.

• Annual Conference of KIPS
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• 2017.04a
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• pp.242-245
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• 2017

기존의 엔진제어기(ECU)는 주요 mapping data(ECU에 대응되는 값)들에 대해서 기밀성과 무결성을 제공하는 보호 기법의 부재로 인해 임의적인 튜닝이 가능하다는 특징이 존재하였다. 이로 인해 자칫 잘못된 튜닝이나 악의적인 조작이 발생할 수 있는 여지가 있으며, 이는 차량 엔진 및 조작의 안정성을 떨어뜨림과 동시에 운전자 및 보행자들의 안전을 위협할 수 있다는 문제가 있다. 이에 본 논문에서는 ECU에 적용되는 Firmware의 주요 mapping data를 안전하게 암호화하는 방식을 제안하며, 이 과정에서는 차량의 식별 및 ECU에 mapping 되는 data의 무결성 검증을 위해 인증서를 사용하는 방식을 제안한다. 본 논문의 제안을 통해 주요 mapping data를 안전하게 보호하는 기술을 통해 차량의 안전성을 유지할 수 있다.

• 한국정보통신설비학회:학술대회논문집
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• 2002.08a
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• pp.213-219
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• 2002

본 논문은 상용 OS 인 windows CE 기반의 PDA에서 음성으로 각 응용 프로그램 을 실행하는 방법 및 구성을 제시한다. PDA는 기존 desktop PC 에 비해 사용자 입력수단이 많지 않고, 그 사용법조차 까다롭다. 예를 들어 SIP(Soft Input Panel)을 이용하여 채팅을 하거나 인터넷 웹 브라우저에 주소입력조차 쉽지 않다. 이에 KT의 자체 개발한 음성인식엔진을 이용하여 PDA내 응용프로그램 과 사용자입력 요구사항을 원활히 연결, 보다 편리한 사용자 입력인터페이스를 제공한다. KT의 음성인식엔진은 corpus 기반으로 HMM 모델을 이용, 사용자 음성을 인식하여 그 결과를 출력한다. 본 논문에서는 PDA에서의 이러한 음성인식엔진을 이용, 다수의 응용프로그램을 실행하고 제어하는 구성과 패턴을 제시한다.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.2
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• pp.89-95
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• 2003

We consider a problem of application of analytical redundancy to engine synchronization process of spark ignition engines, which is critical to timing for every ECU process including ignition and injection. The engine synchronization process we consider here is performed using the pulse signal obtained by the revolution of crankshaft trigger wheel (CTW) coupled to crank shaft. We propose a discrete-time linear model for the signal, for which we construct FDI (Fault Detection & Isolation) system consisting residual generator and threshold based on linear observer.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.12 no.6
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• pp.125-131
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• 2013

This study was carried out to develop a diesel engine for marine propulsion. This marine diesel engine was developed based on a 500Ps vehicle diesel engine. Many main parts, such as the intercooler, radiator, and engine controller were designed for the marine diesel engine. The intercooler was designed to be of sea water cooling type; inlet air is cooled by sea water. Engine coolant is cooled by sea water in the radiator too. The water cooling heat exchanger has high cooling performance. In the cooling system, consists of the intercooler and the radiator, the sea water passes through the intercooler and then the radiator, in sequence. This process is very effective compared to the reverse method in which sea water passes through the radiator and then the intercooler, in sequence. The control performance of the engine controller and the fuel injection rate were improved using an engine speed controller. This system was tested on an engine dynamometer and an exhaust gas analyzer using the marine diesel engine test method. Test results show that the 500Ps marine diesel engine satisfied the IMO NOx regulations; Tier II.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.10a
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• pp.201-204
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• 2004

In this study, the GSP and in-house numerical codes have been used for analyses of the on-design, static off-design and dynamic off-design performances. Through the various missions including altitude, velocity, and power variations static engine performance have been investigated. The dynamic engine performances based on these complicated variations have been also analysed. Especially, the power, engine rpm and heat overload characteristics of a turbine have been estimated with the response time through the control of a throttle setting rather than a power setting. It could be applied to the FADEC system as an engine control device.