흡배기 압력을 이용한 터보과급 디젤엔진의 EGR율 예측에 관한 연구

정재우(Jaewoo Chung),강정호(Jungho Kang),김남호(Namho Kim),정수진(SooJin Jeong),김병수(ByoungSoo Kim),강우(Woo Kang) 한국자동차공학회 2008 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

In this paper, it is discussed that the prediction or calculation model of EGR rate in a Diesel engine equipped with VGT(variable geometry turbocharger) and HPL(high loop pressure) type EGR system using intake and exhaust pressure. The precision of prediction of EGR rate is based on the precision of engine volumetric efficiency and residual gas fraction models. So, volumetric efficiency and residual gas fraction models are constructed using engine test results and then EGR rate model are evaluated. EGR model using intake and exhaust pressure is simple for engine application and the using of EGR model could be support the more easy engine calibration and construction of engine modelling.

시제작 DME 자동차의 VGT와 EGR의 적용에 관한 연구

정재우(Jaewoo Chung),강정호(Jeongho Kang),김남호(Namho Kim),이호길(Hogil Lee),정수진(Soo-Jin Jeong),강우(Woo Kang) 한국자동차공학회 2009 한국자동차공학회 부문종합 학술대회 Vol.2009 No.4

In this steady, mode tests(NEDC, CVS75) of proto-type common-rail DME vehicle were performed to investigate on the effect of EGR and VGT application. To these researches, VGT model , engine model and construction of engine calibration process for engine control set maps were performed . Also the limit A/F of a DME engine considering emitted CO concentrations and VGT mating property with DME engine. As the vehicle tests results, increasement of inlet air flow with VGT system reduced HC and CO concentrations, and application of EGR reduced NOx emission of DME vehicle.

WGT 디젤엔진의 공기순환계보정 모델에 관한 연구

정재우(Jaewoo Chung),김남호(Namho Kim),임창현(Changhyung Lim),김덕진,김기용(Kiyong Kim) 한국추진공학회 2014 한국추진공학회 학술대회논문집 Vol.2014 No.12

최근, 차량의 연비 성능 개선을 위한 많은 연구들이 이루어지고 있으며, 터보과급기는 엔진의 연료소모 및 배기성능 개선을 위한 핵심 기술로 간주되고 있다. 그러나, 과급기와 EGR등을 가지는 흡기시스템의 최적 작동을 위한 실험적 방법의 엔진보정 과정은 흡기시스템의 폐회로 특성에 기인하여, 많은 수고가 수반되어진다. 이에 본 연구에서는 WGT용 디젤엔진의 부품을 평균값 모델을 이용하여 함수화하고, 이를 활용하여, 전체 흡기계시스템에 대한 간단한 구조의 모델을 구성하였다. 특히, WGT 모델의 간략화를 통하여, 전체 계산과정을 간단화 할 수 있었다. 이의 간단한 흡기시스템 모델과 과급기의 압축기 내 작동점의 선정을 통하여, EGR율을 계산할 수 있었으며, 이의 계산 과정은 향후 수치적 방법의 엔진보정과정 개발에 활용될 수 있을 것으로 기대한다. Recently, many researches on improvement of a vehicle fuel economy have been performed and turbocharger has been a key technology for improvement of engine fuel consumption and emission performance. But, experimental engine calibration process for optimal operating with the air-breathening system including turbocharger and EGR(exhaust gas recirculation) needs so much efforts caused by the characteristics of the closed loop air system. So, in this study, some components mean value models(based on engine test results) of a WGT type Diesel engine have been composed. And then, the simplified engine air-breathening system model has been composed. Especially, WGT(waste gate turbocharger) model has been simplified, so, total calculation process could be simplified. Using composed simplified engine model(mean value engine model) and assumed compressor operating points, EGR rate could be predicted. And, these calculation process would be used as a base algorithm for numerical engine calibration process development.

LCD공정에서 스토커시스템 성과측정 모델

정재우(Jaewoo Chung),김판수(Pansoo Kim) 한국산업경영시스템학회 2011 한국산업경영시스템학회지 Vol.34 No.3

The stocker system is another name of automated storage and retrieval system (AS/RS) and being popularly used as main material handling tools in Liquid Crystal Display (LCD) and semiconductor fabrication facilities. Recently the use of the stocker system has been extended to transportation from conventional storage and retrieval in LCD fabrication facilities. Toolsets are connected in the ground level of the stocker system and 4~6 stories of the shelves are placed in the upper or lower ground level. As a consequence of the more sophisticated design, move requests imposed on the system greatly increased. For solving this problem, the industry adopted the dual-robot stocker system that two robots are moving along the same guide line in the stocker system. This research develops a closed-form solution to estimate a delivery rate of the dual robot stocker system under given design and operation parameters. Using this stochastic model, industry practitioners could analyze performance levels under given various design parameters, and ultimately the model helps optimizing the design parameters.

WGT의 터빈 효율 특성에 관한 연구

정재우(Jaewoo Chung),김남호(Namho Kim),임창현(Changhyun Lim),김기용(Kiyong Kim) 한국자동차공학회 2014 한국자동차공학회 부문종합 학술대회 Vol.2014 No.5

스핀 오프(Spin-off)와 재조합 문화(Recombinant Culture)로서의 장르혼합 현상

정재우(Chung, Jaewoo) 한국영화학회 2003 영화연구 Vol.- No.22

In this study, I am proposing the cause and effect of mixing genres. In researching the cause of mixing genres, I use the Gitlin's notions such as spin-off and recombination. Gitlin proposed spin-off and recombination as the way to control the success in market. Spin-off is the notion of using the existing image in other films and media. For example, in the director Kwak jae-young' s 〈My sassy Girl〉 (2001), the female protagonist, Ji-hyun Jun is using the image in her old film and CF. And recombination is the notion of mixing the important elements of the popular films, For example, 〈My sassy Girl〉 is the mixed genre with melodrama, comedy and action film. The effect of mixing genres made the inconsistent text. Each genre has the exclusive icon, convention, and formula. Mixing genres is consisted of all these elements from each different genre. As a result, it made contradiction within conventions of each genre. So the text such as 〈My sassy Girl〉 doesn't continuously keep the dominant ideology, especially patriarchism. As a result, the text becomes open and the audiencs have the opportunity of making meaning.

영화 시장에서 3D 입체 영화의 시장 행위와 성과에 관한 연구

정재우(Jaewoo Chung) 한국영화학회 2012 영화연구 Vol.0 No.54

Technical parts and Aesthetics of 3D cinema such as Avatar(2009), Natalie(2010) and Sector 7(2011) were studied and analyzed. These studies are needed. But 3D cinema should be studied in approach of the industry because movies are produced, released, screened in market. So this essay focuses on analyzing 3D cinema on the base of Industrial organization theory consisting of market structure - market conduct - market performance. The market structure of film industry is analyzed. The result is following. The entry barrier is low so that a lot of new movie companies enter the market easily. So the competition among many movie companies is intense. This situation forces the film company to making differentiated product, differentiated movie such as 3D cinema. Movie companies analyze the market signals to make a decision for the market conduct such as making 3D cinema. The market signals give both good news and bad news. The bad news of the market signals is raising the cost of the production and the problem of the human factor. But the market signals give three good news. First, viewers are wiling to pay higher fee to watch 3D cinema. It is proved by watching Avatar and so on. Second, 3D screen is increased. It means that 3D cinema can be multi-released. Third, 3D TV is supplied broadly. 3D cinema can be sold in the secondary market like IPTV, Internet VOD and so on. These good market signals influence on making 3D cinema, Natalie and Sector 7 in Korea. Lastly, let’s analyze the market performance of the Natalie and Sector 7. These movies are nonprofitable. But the know-hows of producing the 3D cinema such as setting lighting etc is accumulated. These know-hows can be helpful when the next 3D cinema is made.

디젤 PHEV의 엔진 연료 소모 및 NOx 배출량 예측 계산 방법에 관한 연구

정재우(Jaewoo Chung),김남호(Namho Kim),이상운(Sangwoon Lee),이범호(Beumho Lee),김덕진(Deokjin Kim) 한국자동차공학회 2018 한국 자동차공학회논문집 Vol.26 No.3

불확실성을 고려한 장기 전원 포트폴리오의 평가

정재우(Jaewoo Chung),민대기(Daiki Min) 한국경영과학회 2012 한국경영과학회지 Vol.37 No.3

This paper presents a portfolio model for a long-term power generation mix problem. The proposed portfolio model evaluates generation mix by considering the tradeoffs between the expected cost for power generation and its variability. Unlike conventional portfolio models measuring variance, we introduce Conditional Value-at-Risk (CVaR) in designing the variability with aims to considering events that are enormously expensive but are rare such as nuclear power plant accidents. Further, we consider uncertainties associated with future electricity demand, fuel prices and their correlations, and capital costs for power plant investments. To obtain an objective generation by each energy source, we employ the sample average approximation method that approximates the stochastic objective function by taking the average of large sample values so that provides asymptotic convergence of optimal solutions. In addition, the method includes Monte Carlo simulation techniques in generating random samples from multivariate distributions. Applications of the proposed model and method are demonstrated through a case study of an electricity industry with nuclear, coal, oil (OCGT), and LNG (CCGT) in South Korea.

운송시간의 예측을 통한 물류정체 통제 모형

정재우(Jaewoo Chung),허연호(Yeonho Hur) 한국경영과학회 2012 經營 科學 Vol.29 No.1

The automated material handling systems today are playing ever more important roles in semiconductor/LCD fabrication facilities. Recently they became more flexible, intelligent, and speedy than in the past. The facilities have been fully automated because the size and weight of the unit loads used in the facilities were being increased beyond the limits that a human operator can handle. This research develops an efficient procedure to streamline the delivery of unit loads by the automated material handling system (AMHS). For this task, the research employs the event scheduling theory that has been successfully used in the both academia and industry. The developed procedure was applied to an actual LCD fabrication facility and improved the performance of an existing material handling system.