• 한국연소학회:학술대회논문집
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• 한국연소학회 2014년도 제49회 KOSCO SYMPOSIUM 초록집
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• pp.233-234
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• 2014

Lean-rich combustion system was composed both fuel-lean and fuel-rich flame at once. Each of fuel-lean and fuel-rich combustion types to reduce Thermal $NO_x$ and obtain flame stability. This study was confirmed a stability of flame through variation of flame shape that EGR was applied and compared the emission characteristics of EGR lean-rich combustion system to normal premixed combustion system at real condition to review a utility of the system. As a result, emission index of $NO_x$ and CO generated from EGR lean-rich combustion system at global equivalence ratio is 0.85 just half level($NO_x$ 0.31 g/kg, CO 0.08g/kg) compared to the amount generated from normal premixed combustion system at equivalence ratio is 0.78.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2012년 추계학술대회
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• pp.453-460
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• 2012

To maximize the operational efficiency of production and operations systems, Six Sigma and Lean Production System have been widely used. The main focus of Six Sigma is reducing variations, whereas that of Lean Production System is eliminating losses. To take advantage of the two approaches Six Sigma and Lean Production System was integrated into Lean Six Sigma, and the integrated approach has been used in recent years. In the implementation of Lean Six Sigma, the problems under consideration have often physical or technical contradictions which are difficult to be solved by conventional methods. To solve such contradictions TRIZ is useful in many cases. In this thesis, it is considered that how TRIZ can be applied to Lean Six Sigma. An integrated road-map of Lean Six Sigma and TRIZ is suggested and some cases are reviewed.

• 한국건설관리학회논문집
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• 제6권6호
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• pp.152-159
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• 2005

린 건설은 건설 관리의 새로운 방향을 제시해준다. 제조업체로부터 시작된 린 건설은 제조업의 생산활동과는 판이하게 다를 수 있는 건설업의 생산 업무를 효율적으로 조정해 주는데 역점을 두고 있다. 미국 LCI협회는 작업 흐름의 관리와 보다 효율적인 공정 및 계획 관리를 위해 최종 계획 관리 시스템을 개발하여 건설업체에 보급, 린 건설의 활성화를 유도하고 있는데, 이것이 바로 라스트 플래너 시스템(Last Planner System: LPS)이다. 국내에서도 린 건설에 대한 관심이 증가되고 있는 가운데 여러 번에 걸쳐 이 LPS의 소개가 이루어 졌으나 공사현장 참여자들의 비교적 상세한 지침서는 아직 제시된 바 없는 것으로 사료된다. 이에 본 연구에서는 국내 건설현장에서 린 시스템의 보다 효율적인 적용과 수행을 가능케 하기 위한 토대 마련을 제공하고자 하였다. 따라서, 본 연구에서는 문헌조사, 현장 방문을 통한 인터뷰 및 설문조사, 그리고 현장의 린 건설 수행 실태 분석 등을 통하여 린 건설 수행 시 공사 참여자들의 역할과 의무를 정리하였고 린 시스템 중 가장 일반적으로 현장에 적용되어지고 있는 라스트플래너(Last Planner)의 운용 가이드를 제시하였다. 이와 더불어 린 시스템 적용 관리 모델을 제시하여 공사참여자들의 린 건설의 원활한 수행을 유도하는데 도움이 되고자 한다.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.51-59
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• 2009

Lean construction researchers and practitioners have established a new paradigm for managing construction projects. This paradigm stems from insights gained by viewing project delivery as one kind of production and, inspired by the success of the Toyota Production System, leveraging Toyota's 'lean thinking' in the context of such one-of production. Premises of lean construction are that (1) production systems are riddled with variation, (2) variation can be good or bad, but most of it is bad, (3) most of this variation-good or bad-is self-inflicted; consequently 'lean' passionately promotes good- and relentlessly eradicates bad variation. This paper surveys a few of many lean construction means to manage variation. Lean thinking encompasses a lot more than thinking about variation, but that is the lens used here through which construction project management is viewed. Pairing these premises with lean variation-management tools may help readers broaden the insights they can gain from reading the lean construction literature.

• 산업공학
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• 제12권3호
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• pp.468-479
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• 1999

Lean production system can be defined as customer(product)-oriented production system with small lot size and flow-shop layout based on the JIT(Just-in-time) principles. In this paper, we introduce a case example of implementation of the Lean product ion system for manufacturing line of electronic component which has both machine processes and manual jobs. We also investigate the issues of implementing the Lean production system with the viewpoints of layout design scheme and JIT management rules. In the layout design, we propose the cell-line which has flow-shop layout with small lot size. In the management rules, the superior cell rule is applied in order to boost the needs of kaisen up. As the results of implementing the Lean production system, production lead time is decreased from 5 days to 1.5 days and also productivity and quality level arc surprisingly increased.

• 한국연소학회지
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• 제20권2호
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• pp.28-35
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• 2015

In this study, the CH4/air lean-rich combustion system with exhaust gas recirculation (EGR) was investigated to explore the potential for lowering pollutant emissions. To achieve this purpose, experiments of lean-rich combustion system with EGR were conducted to measure the changes in the characteristics of the pollutant emission and flame shape with various equivalence ratios and EGR rates. Here, this study was applied to the fuel distribution ratio of 3:1 for the formation of the lean and rich flames. Additionally, the results were compared with $CH_4$/air lean premixed combustion system. The results show that flame shape of lean-rich combustion system was determined by lean and rich equivalence ratios (${\Phi}_L$ and ${\Phi}_R$) and stratified flame was formed with increasing ${\Phi}_R$. According to the pollutant emission characteristics based on experimental results, the NOx and CO emission index (EINOx and EICO) decreased with increasing EGR rate. Especially, in the range needed to form a stable flame, the reduction rates of EINOx and EICO were approximately 47% and 48% for an EGR rate of 25%, global equivalence ratio of 0.85 and ${\Phi}_L$ of 0.80 compared with lean premixed combustion system (${\Phi}$ = 0.78).

• 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
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• 제14권4호
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• pp.47-54
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• 2008

Preconstruction process in a lean project delivery system was studied in one large healthcare project working for a general contractor. Researchers joined a new lean delivery project for approximately six weeks and participated in preconstruction process including design coordination, management coordination, and target costing while concurrently interviewing other project participants and employees, recording activity in meetings, and otherwise observing the process. The preconstruction process in lean project delivery system, called integrated project design, showed many benefits such as brining expertise of downstream players (i.e., mechanical and electrical contractors) into the design phase. However, lack of leadership and lack of design-integrator blocked the successful application of a new concept of design process.

• 한국연소학회지
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• 제14권2호
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• pp.18-25
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• 2009

Fuel lean reburning method is very attractive way in comparison with conventional reburning method for reducing NOX. Meanwhile, the knowledge of the how flue gas re-circulated, temperature distribution and species concentration is crucial for the design and operation of an effective fuel lean reburning system. For this reason, numerical analysis of fuel lean reburning system is a very important and challenge task. In this work, the effect of fuel lean reburn system on NOX reduction has been experimentally and numerically conducted. Experimental study has been conducted with a 15kW lab scale furnace. Liquefied Petroleum Gas is used as main fuel and reburn fuel. To carry out numerical study, the finite-volume based commercial computational fluid dynamics (CFD) code FLUENT6.3 was used to simulate the reacting flow in a given laboratory furnace. Steady state, three dimensional analysis performed for turbulent reactive flow and radiative heat transfer in the furnace.

• 한국분무공학회지
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• 제14권4호
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• pp.171-177
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• 2009

This study proposes a new stratified charge system for low emission and ultra lean burn. In order to examine combustion characteristics of the new system, sparkplug with a hole at positive pole and a common CNG injector for injecting fuel were used in this study as injector-type spark plug. The new stratified charge system injects fuel of extremely small quantities and ignites mixture around sparkplug gap. Also, the system was fitted in a visualized constant volume chamber. Then, for analysis of the combustion characteristics, we examined combustion pressure, lean inflammable limit, and visualized combustion flame according to equivalence ratio by comparison with homogeneous charge (HC) method and the new stratified charge (SC) method. As results of this study, in the case of using this system, the propagation speed of initial flame was increased and total combustion period was reduced in the ultra lean burn in the same equivalence ratio. These phenomena occurred clearly under the conditions of lean equivalence ratio. Furthermore, the lean inflammable limit of mixture was extended by using the injector-type spark plug.

• 대한안전경영과학회지
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• 제14권1호
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• pp.117-122
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• 2012

This paper deals with the productivity increment through construction of lean production system for automobile factory in China. This lean production system has been progressed according to 5 steps. Step 1 is the work preparation. Step 2 is the process design. Step 3 is the establishment of method to count production quantity. Step 4 is the establishment of measuring method for input and output. Finally, step 5 is the construction of flexible production system able to adapt for environment change. This lean production system is expected to obtain the productivity increment by 50% for plastic plant and reduction by 50% in inventory quantity.