• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집B
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• pp.847-852
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• 2000

Three dimensional CFD investigations are carried out to understand the complex flow field in a gas turbine combustor with multi-element fuel injectors. The gas turbine considered here is the GE7FA model which has aye fuel injectors in each combustor can and utilizes lean-premixed combustion to meet nitric oxide emission requirements. Detailed three-dimensional flow characteristics and fuel-air mixture formation process inside the fuel nozzle and gas turbine combustor including five swirl nozzle tips are analyzed using commercial FLUENT code.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2010년도 춘계학술발표논문집 2부
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• pp.1049-1052
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• 2010

생산성 및 품질혁신을 위하여 Lean 6시그마에 대한 다양한 국외 적용사례는 존재하나, 고도의 하이테크 산업이며 품질을 최우선으로 삼는 항공산업에 적용 및 평가에 대한 국내 연구사례는 거의 전무한 것이 현실이다. 본 연구에서는 린 6시그마 기법이나 사상들이 국내 항공산업 프로세스의 생산성 및 품질을 향상시키는데 과연 적합한지 판단하여, 현장적용을 사례로 적용 방법론을 제안하는데 목적이 있다.

• 한국자동차공학회논문집
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• 제7권8호
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• pp.24-33
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• 1999

This paper investigate the effects of the variations of engine operation condition in the flame kernel formation and developmnet . A model for calculating the initial kernel development in spark ignition engines is formualted. It considered input of electrical energy, combustion energy release and heat transfer to the spark plyg, cylinder head, and unburned mixture. The model also takes into accounts strain rate of initial kernel and residual gas fraction. The breakdown process and the subsequent electrical power input initially control the kernel growth while intermediate growth is mainly dominated by diffusion or conduction. Then, the flame propagates by the chemical energy and turbulent flame expansion. Flame kernel development also influenced by engine operating conditions, for example, EGR rate, air-fuel ration and intake manifold pressure.

• 산업경영시스템학회지
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• 제31권2호
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• pp.36-42
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• 2008

As competition shifts from being a company oriented one to a supply chain oriented, an effective SCM(supply chain management) becomes a necessary strategy for any successful businesses. But, it is not easy to form a successful SCM, because the individual desire of participants conflict with others. These desires affect the performance of SCM and cause waste of cost and time. Analyzing a supply chain of discount retailers, this paper eliminates idle time and improves the process with rearranging the reorder closing time(reorder point). For win-win strategy, this work reveals the reorder closing time is an important factor. It is possible to reduce cost and time on the entire SCM process by just changing the ordering time.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2008년도 정기학술발표대회 논문집
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• pp.222-226
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• 2008

건설산업은 불확실성이 높은 산업으로 이에 따른 비용효용성 향상 및 경쟁력 강화를 위한 연구가 다각적으로 진행되어 왔다. 린 건설의 대표적인 요소기술인 라스트플래너 시스템은 기존의 상의하달식 의사결정체계를 개선한 하의상달식 접근방식으로서, 모든 참여주체가 함께 중 단기 공정계획을 검토 시행하는 체계이다. 이와 같은 린 건설은 최근 들어 건설프로젝트에서 주도적인 역할을 하고 있는 발주자의 적극적인 참여와 전체 생애주기를 총괄할 수 있는 리더역량을 요구하는 방향으로 논의가 전개되고 있다. 그러나 발주자가 참여하는 린 건설이 성공하기 위해서는 건설주체 상호간에 요구하는 니즈(needs)수준과 이를 개선하기 위한 전략들이 우선적으로 고려되어야 한다. 본 연구에서는 건설 시공과정에서의 참여주체 니즈 요소를 규명 분석하고, 중점관리항목과 이들 항목들의 개선가능성을 도출하는 방법, 그리고 이를 기반으로 한 발주자 참여형 린 건설 협업 모델을 제시하였다.

• 동력기계공학회지
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• 제10권3호
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• pp.5-10
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• 2006

In a conventional and lean operating engine, the state of mixture is very important in the combustion and emission characteristics. Lean operation is known to decrease the formation while maintaining a good fuel economy, but the unstable operation due to misfire and erratic combustion prevents engines from being operated at very lean mixtures, so both combustion rates and exhaust emission formation need to be satisfied comparably. In this study, it is designed and experimented the modified engine, and analyzed the combustion and exhaust emission according to the change of engine speed and with adding ozone. The conclusions were drawn out and enumerated as follows. 1. At the experimental result of automobile diesel engine, it has been verified that the formation of particulate matter(PM) gas is able to be lower with the addition of optimum quantities of ozone. 2. Carbon monoxide(CO) was formed by the lack of oxygen and the thermal dissociation in the combustion process. Therefore, with the change of swirl valve's position and addition of oxygen and ozone, CO formation was decreased by the increasing of excessive O2, but it was increased by the temperature of combustion gas growing higher. As a result of the two effects, CO formation was decreased in this study. 3. Hydrocarbon(HC) was formed by the lack of O2, and the flow of mixture in cylinder. According to opening of the swirl valve and adding the oxygen and ozone, hydrocarbon gas was decreased by 20%, 9%, and 27.5%, respectively. 4. Nitric oxides($NO_x$) was strongly affected by the combustion gas temperature. As a result of respectively experimental conditions, $NO_x$ formation was increased about 20% due to (be the) high(er) combustion gas temperature.

• Journal of Animal Science and Technology
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• 제44권4호
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• pp.377-382
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• 2002

본 연구는 1995년부터 2001년까지 한국종축개량협회가 전국 종돈장으로부터 수집한 Land- race, Yorkshire 및 Duroc의 등지방 두께, 일당증체량, 90kg 도달일령, 등심단면적, 정육률, 총산자수 및 복당생존자돈수에 대해 유전적 그룹을 통한 품종효과의 추정과 유전능력 평가를 위하여 96,842두의 산육능력성적과 90,396복의 산자능력자료를 분석하였다. 추정된 품종효과들은 각 품종의 특징을 보여주는데 Landrace는 등지방, 정육률 및 총산자수에서 우수하였고, Yorkshire는 정육률, 등심단면적, 총산자수 및 복당생존자돈수에서 좋은 결과를 보여주었으며, Duroc은 90kg 도달일령과 일당증체량에서는 우수하였지만 가식부위를 결정하는 등지방두께와 정육률, 번시능력을 보여주는 산자수에서 다른 품종에 뒤지는 것으로 나타났다. 유전적 그룹을 통한 품종효과의 추정으로 품종별로 능력평가를 하는 노력을 절감할 수 있고 또한 F1 잡종돈이 포함되어도 평가할 수 있다.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2009년도 춘계학술대회
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• pp.531-539
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• 2009

The environment of automobile industry in the world is rapidly changing. It is changing of high oil price, technology, environment and construction of competition by newly rising an economic district. Automobile company is focusing on three issue because they want to reinforce competition of automobile industry in the world. That is innovation of production profit management through quality management and Lean. Chance of success is separated in R&D, providing distribution, manufacture, distribution, selling in automobile industry. Emphasis on development process, distribution process, manufacture process, circulation and selling process for strengthening the competitiveness and guarantee. In this thesis, we try to analysis the data set period of automobile production by using survival analysis. While using mean comparison of general statistics commit mistakes, survival analysis can used for including censored data in order to heighten analysis efficiency.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2011년도 추계학술대회
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• pp.557-561
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• 2011

The study proposes three types of production lead time according to the production or demand pattern. First of all, it discusses the difference of three lead times. While pitch time and cycle time are used in push system with process stock and mass conveyor production, the tact time is used in pull system like as JIT based lean production system.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2015년도 제51회 KOSCO SYMPOSIUM 초록집
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• pp.177-180
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• 2015

The chemical aspects of primary reference fuel (PRF)/air mixture under RCCI conditions are investigated to provide fundamental insights into the ignition characteristics of RCCI combustion. Chemical explosive mode analysis (CEMA) is adopted to understand the ignition process of the lean PRF/air mixture by identifying controlling species and elementary reactions at different locations and times.