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다양한 서비스들의 요구사항을 만족하는 GMPLS 기반 복구 기법
이용규,Lee, Yonggyu 한국정보통신학회 2022 한국정보통신학회논문지 Vol.26 No.5
다양한 모바일 디바이스의 보급 확대는 폭발적인 데이터 트래픽의 증가로 이어졌으며, 이는 다시 다양한 형태의 서비스에 대한 수요로 이어졌다. 트래픽의 증가와 다양한 서비스 요구사항을 만족시키기 위해서, 하나의 광섬유만으로도 수십 테라비트를 운반할 수 있는 광 인터넷 기술이 활발하게 연구되고 있다. 넓은 대역폭 때문에 하나의 광 링크는 다양한 서비스를 수용할 수 있다. 이에 따라 각 서비스별 요구사항을 만족하면서 광 인터넷의 생존성을 보장할 수 있는 기술이 요구되고 있다. 그래서 본 논문에서는 GMPLS를 기반으로 IP over WDM 네트워크에서 다양한 서비스 요구사항과 생존성 문제를 다룰 수 있는 새로운 기법을 제안한다.
이용규,Lee, Yonggyu The Society of Digital Policy and Management 2022 디지털융복합연구 Vol.20 No.4
In medical area, very high resolution images, which is loss sensitive data, are used. Therefore, the use of optical internet with high bandwidth and the transmission of high realiability is required. However, according to the nature of the Internet, various data use the same bandwidth and a new scheme is needed to differentiate effectively these data. In order to achieve the differentiation, optical delay line buffers are used. However, these buffers is constructed based on some optimal values such as the average offered load, measured data burst length, and basic delay unit. Once the buffers are installed, they are impossible to reinstall new buffers. So, the scheme changing burst length dynamically was considered. However, this method is highly unstable. Therefore, in this article, in order to guarantee the stable operation of the scheme, the analysis of operation conditions is performed. With the analysis together with the scheme, high resolution medical data with the higher class can transmit stably without loss. 의료 현장에서는 매우 고해상도의 이미지를 사용하고 있으며, 이는 손실에 매우 민감한 정보이다. 이에 따라 높은 대역폭뿐만 아니라 고신뢰성 전송을 제공할 수 있는 광 인터넷의 활용이 요구되고 있다. 그러나 인터넷의 특성상 다양한 종류의 데이터가 동일한 대역폭을 활용하게 되고, 이를 효과적으로 차별화할 수 있는 수단이 요구되고 있다. 이를 위해 광 지연 라인 버퍼가 많이 활용되고 있다. 그러나, 이러한 버퍼는 제공 부하, 측정된 데이터 버스트 크기, 기본 지연 유닛 등과 같은 최적값을 이용해 구성된다. 광 버퍼는 한 번 설정되면 변경할 수 없다. 그러므로 데이터 버스트 크기를 동적으로 변경시키는 방법이 활용되고 있다. 그러나 동적으로 버스트의 길이를 변화시키는 것은 상당한 불안정성을 내포하고 있다. 이에 본 논문에서는 안정적인 동작을 보장할 수 있는 동작 조건을 분석하고자 한다. 본 논문의 기법을 활용해 높은 우선순위의 고해상도 의료 데이터를 손실 없이 안정적으로 전송할 수 있다.
승용디젤엔진에서의 디젤, GTL, 바이오디젤의 혼합유 적용에 따른 배출물 특성에 관한 실험적 연구
이용규(Yonggyu Lee),문건필(Gunfeel Moon),최교남(Kyonam Choi),정동수(Dongsoo Jeong) 한국자동차공학회 2009 한국자동차공학회 부문종합 학술대회 Vol.2009 No.4
An experimental study was carried out to investigate the emission characteristics for various alternative fuels in a 2.0 liter 4-cylinder turbo-charged diesel engine. The conventional diesel fuel, neat GTL(Gas to Liquid), blends of diesel and bio-diesel(BD20), and blends of GTL and biodiesel (G+BD20, G+BD40) were used in this study where the biodiesel was produced from blends of waste cooking oil and soy bean oil by volume ratio of 7 to 3. Noticeable enhancement of exhaust emissions compared to diesel fuel, except for NOx emission, were observed with the blending of bio-diesel with diesel and GTL fuel at various engine speed and loads, where there is a maximum enhancement of around 50% for gaseous emissions and 80% for PM emission for the case of GTL and biodiesel blends(G+BD40). Much enhancements of gaseous emissions are observed for the case of BD20 fuel than the case for G+BD20 fuel due to better fuel properties of GTL. For PM size distributions, noticeable decrease of PM number concentration for all particle sizes less than 300 ㎚ was observed with the blending of biodiesel, while there is a slight increase number concentrations of particle diameter less than 50㎚ for cases of EGR conditions.
분리형 블레이드를 위한 4.3MW급 풍력 발전 시스템 블레이드의 고효율 공력 성능 연구
이용규(Yonggyu Lee),박현범(Hyunbum Park) 항공우주시스템공학회 2023 항공우주시스템공학회지 Vol.17 No.6
Recently, renewable energy has been widely used as a source of wind energy and solar energy due to the shortage of fossil fuels and environmental problems. Against this backdrop, wind energy is emerging as an important energy source, and the wind power market is showing rapid growth worldwide. In this study, a high-efficiency wind turbine blade was designed with an integrated blade aerodynamic design for prior research on separate blades. The blade airfoil was applied as NACA 4418, and it was verified by comparing it with the analysis results to evaluate the newly designed blade.
Air hybrid 엔진의 구동 특성에 관한 실험적 연구
이용규(Yonggyu Lee),김용래(Yongrae Kim),김영민(Youngmin Kim),박철웅(Chulwoong Park),최교남(Kyonam Choi),정동수(Dongsoo Jeong) 한국가스학회 2011 한국가스학회지 Vol.15 No.5
엔진의 제동시의 유효일을 이용하여 고압의 압축 공기를 저장하고 운전 시에는 저장된 압축 공기를 동력원으로 사용하는 신개념의 Air hybrid 엔진의 구현 가능성 검토를 위한 실험적인 연구를 진행하였다. Air hybrid 엔진 시스템의 구현을 위하여 연구용 단기통엔진을 개조하였고, 배기 밸브 중의 하나에 독립 가변 밸브리프트 시스템을 장착하여 압축 행정 동안에 고압의 공기를 저장할 수 있도록 하였다. 또한, 엔진의 구동을 위하여 점화플러그 위치에 공기 분사 모듈을 장착하여 팽창행정 중에 고압의 공기를 분사할 수 있도록 하였다. 압축 공기 저장 모드에서는 800rpm 아이들 조건에서 800 사이클 동안 30리터의 공기 저장 탱크를 최대 13 bar 까지 충전할 수 있었고, 충전된 고압의 공기를 이용하여 800rpm 아이들 조건에서 0.41 bar의 평균도시유효압력의 일을 얻을 수 있었는데 이것은 정상적인 아이들 조건보다 1.1 bar의 유효일이 증가한 것이다. A preliminary experimental study of new concept air hybrid engine, which stores compressed air in the tank during braking and re-use it to propel vehicle during crusing or acceleration, was carried out in this study. A single cylinder engine was modified to realize the concept of air hybrid engine. Independent variable valve lift system was adopted in one of the exhaust valves to store the compressed air into the air tank during compression period. An air injector module was installed in the place of spark plug, and the stored compressed air was supplied during the expansion period to realize air motoring mode. For air compression mode, the tank with volume of 30 liter could be charged up to more than 13 bar. By utilizing this stored compressed air, motoring work of 0.41 bar of IMEP(Indicated mean effective pressure) at maximum can be generated at the 800rpm conditions, which is higher than the case of normal idle condition by 1.1 bar of IMEP.
전자 제어 연료 분사 방식의 4행정 50㏄급 소형 이륜차 엔진 개발
이용규(Yonggyu Lee),정영수(Youngsoo Jeong),강인호(Inho Kang),문건필(Gunfeel Moon),최교남(Kyonam Choi),정동수(Dongsoo Jeong) 한국자동차공학회 2010 한국자동차공학회 부문종합 학술대회 Vol.2010 No.5
In recent years, the applied engineering solutions in small engines have been extended down to 50 ㏄ displacement engines to satisfy the more stringent emission regulation and increasing customer demands. The existing small engines, such as air-cooled 2 stroke or 4 stroke engines with carburetor system, have to enhance their mixture preparation and also have to call for the implementation of enhanced engine technologies into small engine category, which is as well known for automotive applications. In this paper, water-cooled 4 stroke 50 ㏄ small engine with electronic control fuel injection system were developed to enhance fuel economy and to meet EURO Ⅲ emission regulations. The engine power of 4 stroke with EMS was equivalent to 2 storke engines while the maximum torque increased due to extended engine speed. In the CVS 40 mode test, more than 50% enhancement of fuel consumption rate compared to carburetor system was obtained with lower emission level due to accurate closed loop air fuel ratio control.
고압 커먼레일 직분식 디젤 엔진에서 GTL 연료의 연소 특성에 관한 연구
이용규(Yonggyu Lee),김혜민(Hyemin Kim),최교남(Kyonam Choi),정동수(Dongsoo Jeong),김병준(Byoungjun Kim),차경옥(Kyungok Cha) 한국자동차공학회 2006 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-
The GTL(Gas to liquid) is one of the most favored candidates for alternative fuel in diesel engines. Due to its higher cetane number(more than 75) and almost negligible contents of sulphur and aromatic compounds, enhanced emission characteristics are expected even in the application in diesel engines without any modification. In this study, in-cylinder pressures are analyzed to investigated the combustion and emission characteristics in the single cylinder CRDi(Common rail Direct injection) diesel engines. The ignition delay decreased due to higher cetane number of GTL which results in lower maximum heat release rate during premixed combustion period and lower NOx emissions. THC and CO emissions are also decreased. In multi-cylinder engines, various blending of Diesel and GTL(30%, 50% in volume) are also tested without any modification of enigne controll system to check the applicability of GTL fuel in commercial diesel engines. Noticeable reduction in soot, THC and CO emission are observed without the loss of engine power with equivalent emission characteristic of NOx.
Air hybrid 엔진 기술 개발을 위한 기초 타당성 연구
이용규(Yonggyu Lee),김용래(Yongrae Kim),박철웅(Chulwoong Park),임현식(Hyunsik Lim),최교남(Kyonam Choi),정동수(Dongsoo Jeong) 한국자동차공학회 2010 한국자동차공학회 학술대회 및 전시회 Vol.2010 No.11
A preliminary study of new concept air-hybrid engine, which stores compressed air in the tank during braking and re-use it to propel vehicle during crusing and acceleration, was carried out in this study. A single cylinder engine with displacement volume of 500㏄ and 4 valve DOHC system was modified to realize the concept of air-hybrid engine. Independent variable valve lift system, which can varies valve lift from 0 to 5 ㎜, was adopted in one of exhaust valve to store the compressed air in the air tank during compression stroke. For air motoring mode, air injector module was installed in place of spark plug and compressed air was supplied during the expansion period. The test engine was operated at the engine speed of 800 and 1,500 rpm with various throttle positions. For air compression mode, the tank with volume of 30 liter could be charged up to more than 13 bar at the engine speed of 800 rpm and full throttle condition by optimizing valve lift and timing. For air motoring mode, gas injector for heavy duty compressed natural gas engine was installed in place of spark plug. Compressed air charged in the air tank was injected with this gas injector during the expansion period of piston.