• 한국자동차공학회논문집
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• 제20권4호
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• pp.39-45
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• 2012

Today gasoline engines for vehicular application are not only faced with stringent emission regulation but also with increasing requirements to better fuel economy, while guaranteeing power density. The spray-guided type gasoline direct injection (GDI) engine has an advantage of improved thermal efficiency and lower harmful emissions. Centrally mounted high pressure injector and adjacent spark plug allow stable lean combustion due to the flexible mixture stratification. In the present study, the performance and emissions characteristics of developed spray-guided type GDI combustion system were evaluated at various excess air ratio conditions. The specific fuel consumption and nitrogen oxides ($NO_x$) emissions were reduced due to the achievement of stable lean combustion under flammability limit. Multiple injection strategy was not helpful to improve fuel consumption while further reduction of $NO_x$ emissions was possible.

• 한국인쇄학회지
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• 제29권3호
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• pp.77-96
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• 2011

Most of all manufacturing industries are pursuing the manufacturing process innovation through the production process automation but the printing industry still does not get out of the analog ways of the entire process compared the entire manufacturing industry. Today, many printing enterprises have the difficulties by the short for delivery, multi-item small amount printing, high quality, rise in raw material cost, drop in receiving order cost, and etc. The printing industry can get over these difficulties and issues by implementing the compact workflow line, merge with the others, automatization and networking, minimization of the repetitive operation, efficiency of the working process, optimization of the operators' value creation, minimization of cost and materials and fast make-ready. The object of this thesis establishes the experimental data and study cases applicable in the printing industry by having high labor productivity and work in line with printing industry processes through "lean printing system".

• 대한기계학회논문집B
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• 제34권3호
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• pp.283-290
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• 2010

이 연구의 목적은 NOx 저감을 위한 연료희박 재연소 기법과 산화제 다단 연소 기법의 혼합 기법의 실험적 연구를 목표로 한다. 실험용 연소로에서 재연소 연료 분율, 재연소 노즐 직경, 산소부하도 및 재연소 연료 분사 위치등을 고려한 실험을 수행 하였다. 또한, 산화제 다단 연소를 통하여 생성된 유동장이 NOx 저감에 미치는 영향을 연료희박 기법의 NOx 저감율과 비교하는 실험을 수행하였다. 실험을 통하여 연료희박 재연소와 산화제다단연소 기법의 혼합 기법이 NOx 저감에 미치는 긍정적인 효과를 관찰 하였다.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2007년도 정기학술발표대회 논문집
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• pp.182-189
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• 2007

건설생산성의 혁신적 향상을 지향하는 린건설(Lean Construction) 구현을 위해 가장 시급히 개선되어야 할 사항은 건설생산 프로세스의 개선과 건설정보의 신뢰성 향상으로 정의될 수 있다. 본 연구에서는 건설생산 프로세스 중 설계/시공단계에서의 개선사항을 설계관리, 자재조달관리, 공정관리 측면에서 도출하고, 각 단계에서 도출된 개선사항을 웹기반 정보시스템으로 실현하여 건설산업 종사자들에게 필요한 정보와 지식을 제공하고자 웹 기반 분산형 건설정보 시스템을 개발하고자 한다. 이를 위해 건설생산 프로세스 각 단계에서의 주요 문제점을 파악하여 개선모델 및 요소기술을 제시하고, 모델의 구현을 위한 시스템 프로토타입을 개발하였다. 설계/자재조달/공정 관리지원 시스템은 웹 기반의 지식관리 시스템을 중심으로의 통합을 추진할 예정이다.

• 대한기계학회논문집
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• 제11권6호
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• pp.991-1000
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• 1987

본 연구에서는 과농-희박 연료장에서 화염들의 상호작용에 관하여 이론적 해 석 및 실험적 검증을 통해 연구하였고, 이 중 특히 두 개의 예혼합화염 사이에 확산화 염이 형성되어 세 개의 화염이 존재하는 영역을 고찰하였다.

• 한국자동차공학회논문집
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• 제10권4호
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• pp.23-32
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• 2002

Combustion and flame propagation characteristics of the liquid phase LPG injection (LPLI) engine were investigated in a single cylinder optical engine. Lean bum operation is needed to reduce thermal stress of exhaust manifold and engine knock in a heavy duty LPG engine. An LPLI system has advantages on lean operation. Optimized engine design parameters such as swirl, injection timing and piston geometry can improve lean bum performance with LPLI system. In this study, the effects of piston geometry along with injection timing and swirl ratio on flame propagation characteristics were investigated. A series of bottom-view flame images were taken from direct visualization using an W intensified high-speed CCD camera. Concepts of flame area speed, In addition to flame propagation patterns and thermodynamic heat release analysis, was introduced to analyze the flame propagation characteristics. The results show the correlation between the flame propagation characteristics, which is related to engine performance of lean region, and engine design parameters such as swirl ratio, piston geometry and injection timing. Stronger swirl resulted in foster flame propagation under open valve injection. The flame speed was significantly affected by injection timing under open valve injection conditions; supposedly due to the charge stratification. Piston geometry affected flame propagation through squish effects.

• 한국자동차공학회논문집
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• 제10권4호
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• pp.77-84
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• 2002

For the purpose of obtaining a fundamental data which is needed to develope the port injection type charged LPLi engine system, we manufactured intake port injection system of liquid charging LPG and modified heavy duty single cylinder LPLi engine from heavy duty diesel engine. Engine output and emission characteristics were analyzed under variable air/fuel ratio and charging pressure. Since LPG is consisted of propane and butane, we investigated combustion characteristics using this two kinds of fuel. From the result of charging engine performance test, engine torque increase about 30% ∼ 40% with 0.3bar charging pressure. In low speed condition, as charging pressure increase, combustion stability improve ill lean bum condition, but, in high speed condition, combustion stability make worse in lean bum condition. We know that engine output decreased rapidly from the condition of air excess ratio 1.3. In addition, we measured emission characteristics under the lean bum and charging condition. From this experiment, we found that CO emission is out of the question in the range from stiochiometric to lean burn and charging condition, but charging pressure has influence on HC emission.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2007년도 정기학술발표대회 논문집
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• pp.647-651
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• 2007

1990년대 초반 제조업의 린 이론에서 응용된 린 건설은 생산성 향상을 위한 이론적 토대 및 실무 적용성이 우수한 모델로서, 낭비요인을 최소화함으로써 수요자가 얻는 가치의 극대회를 목표로 하고 있다. 또한, 린 건설의 요소기술중 라스트플래너시스템(LPS) 방식은 참여자의 협력관계 증진과 일정계획의 실행여부 측정 및 원인분석을 통하여 변이를 저감하며, 궁극적으로 작업의 신뢰도 향상을 지향하고 있다. 본 연구는 플랜트 건설공사 프로세스중 자재조달 및 시운전 단계를 LPS를 활용한 발주자 주도형 린 건설 모델이 생산성 및 가치 향상에 긍정적임을 도출하고, 실무적용을 위한 Framework을 제시하고자 한다.

• International Journal of Automotive Technology
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• 제2권4호
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• pp.147-155
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• 2001

Analysis of the thermodynamic cycle of IC engine from the point of view of economy and emissions was carried out. From this analysis potential capability of engine development was derived. This potential capability is lean-burn engine, fuelled with homogeneous mixture with $\lambda \geq$ 1.4. Several different modes of fuelling were proposed and tested on one-cylinder test engine from the point of view of extending lean operating limit of the engine, emissions and fuel economy. Among them were: fuelling with evaporated preheated gasoline, with gas (LPG evaporated) and with liquid butane. From these modes, fuelling with liquid butane injected to inlet port was selected and finally tested. This novel system of fuelling offered better than standard engine performances and emissions at lean operating limit. These results were validated on full-scale two-cylinder engine.

• 한국품질경영학회:학술대회논문집
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• 한국품질경영학회 2010년도 춘계학술대회
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• pp.55-61
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• 2010

Many enterprises are looking for counterproposals to be survival through innovation activities and to be held on their continuous businesses for their business management environments nowadays. One of the innovation activities is an improvement of Loss and reinforcement of business structure through Lean, TPM. Another one is an improvement of these innovation activities and have achieved lots of outcomes (profits). But most these activities have been applied for only the industries in Automobile, Semiconductor, Aviation, Construction with large enter in Korea. And most of minor cable enterprises don't even try to import these innovation activities excluding some how the small and medium cable enterprise can import the LEAN / 6 Sigma activities effectively with some of sample in real small and medium cable company.