• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2003년도 학술대회지
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• pp.113-119
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• 2003

린 건설이 건설업에서 생산성 향상을 위한 새로운 관리 방식으로 소개되어진 이후 많은 연구들이 린 건설의 성공적 실행을 위해 진행되어져 왔다. 현재 미국 내 건설회사들은 린 건설학회(LCI)에서 개발한 라스트플래너(LPS) 시스템을 현장에 적용해 보고 있으며 몇몇 현장은 성공적인 공사결과를 얻어내고 있어서 향후 린 건설의 도입 가능성을 보다 높이고 있다. 또한 그 결과로 많은 회사들이 다른 회사들이 어떻게 린 건설을 수행하고 있으며, 린 건설의 장단점은 무엇인지, 그리고 자신들의 회사에 적용 가능한 것이 무엇이 있는지에 대한 정보교환에 대한 관심이 높아지고 있다. 본 연구는 사례연구를 통해 린 건설이 얼마나 효과적이며 어느 정도까지 건설현장에 도입되어져 가고 있는지 알아보고자 함에 있었다. 하지만 이 논문에서는 4단계의 LPDS를 간략히 소개하고, 또 사례현장의 개별면담과 설문조사를 통해 얻은 결과를 비교 분석하여 소개하고자 한다. 마지막으로, 린 건설의 국내현장 도입을 위한 몇가지 제안을 .제시하고자 한다. 린 건설은 아직까지 기존의 관리체계의 틀에서 완전히 벗어나지 못하고 있으나 꾸준한 연구와 사례연구를 통해 언젠가는 새로운 공사관리 혁신의 주도 시스템으로 자리 잡을 수 있을 것이라 확신한다.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1996년도 International Conference on Agricultural Machinery Engineering Proceedings
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• pp.780-791
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• 1996

A hybrid image processing system which automatically distinguished lean tissues in the image of a complex beef cut surface and generated the lean tissue contour has been developed. Because of the in homegeneous distribution and fuzzy pattern of fat and lean tissue on the beef cut, conventional image segmentation and contour generation algorithm suffer from a heavy computing requirement, algorithm complexity and poor robustness. The proposed system utilizes an artificial neural network enhance the robustness of processing. The system is composed of pre-network , network and post-network processing stages. At the pre-network stage, gray level images of beef cuts were segmented and resized to be adequate to the network input. Features such as fat and bone were enhanced and the enhanced input image was converted tot he grid pattern image, whose grid was formed as 4 X4 pixel size. at the network stage, the normalized gray value of each grid image was taken as the network input. Th pre-trained network generated the grid image output of the isolated lean tissue. A training scheme of the network and the separating performance were presented and analyzed. The developed hybrid system showed the feasibility of the human like robust object segmentation and contour generation for the complex , fuzzy and irregular image.

• 한국산학기술학회논문지
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• 제15권9호
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• pp.5502-5512
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• 2014

최근까지의 종합군수지원 개발은 정비계획, 지원장비, 보급지원, 군수지원교육 등 ILS 지원성요소의 개발, 획득에 주로 초점을 두었다. 이제는 장기적인 관점에서 무기체계의 운용유지와 총수명주기관리체계(TLCSM)와 같이 지속유지성을 강조하는 제도 등을 고려하여 지원성 분야의 효율성 증대, 비용절감 등 린(LEAN) 관점에서 지원성 전략과 정책이 필요할 때이다. 본 논문에서는 ILS 이론, 린 개념, 린 메인터넌스의 이론적 배경을 살펴보고 이를 바탕으로 군수지원 측면의 린 메인터넌스 프레임워크를 제시하고 정비 전략을 제시하였다. 또한 레이더 체계의 금속형 필터에 대한 린 예방정비(PM) 사례를 정비 시간, 정비 인시, 정비 비용 3가지 측면에서 분석하였다. 마지막으로 무기체계의 지원성요소 측면에서 추진 방향을 제시하였다.

• International Journal of Railway
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• 제1권2호
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• pp.45-58
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• 2008

The concept of lean production originated and was applied mainly to manufacture industries Even proven successful with such companies as Toyota, lean production has to be combined railway transportation production in order to bring its function into full play. The paper analyzes for applicability of lean production in railway transportation production organization, puts forward implementation methods such as transportation resource integration, station-zone organization, dispatch command optimization, railway performance evaluation index system, etc., and makes an exemplification study of lean production of Urumqi Railway Bureau in China, which testifies the applicability and efficiency of railway lean production.

• 한국자동차공학회논문집
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• 제11권3호
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• pp.92-98
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• 2003

An LPG engine for heavy-duty vehicles has been developed using liquid phase LPG injection (hereafter LPLi) system which has regarded as one of the next generation LPG fuel supply systems. In this wort to investigate the lean bum characteristics of heavy-duty LPLi engine, various injection timing (SOI, start of injection) and double ignition method were tested. The results showed that lean misfire limit of LPLi engine could be extended. by 0.2 $\lambda$ value, using the optimal SOI timing in LPLi system. Double ignition method test was carried out by installing the second spark plug and modified ignition circuit to ignite two spark plugs simultaneously. Double ignition resulted in the stable combustion under ultra lean bum condition, below $\lambda=1.7$, and extension of lean misfire limit compare to ordinary case. Therefore, LPLi engine with optimal SOI and double ignition method could be normally operated at around $\lambda=1.9$ and showed higher engine performance.

• 대한기계학회논문집B
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• 제32권3호
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• pp.216-223
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• 2008

Reburning is a useful technology in reducing nitric oxide through injection of a secondary hydrocarbon fuel. In this paper, an experimental study has been conducted to evaluate the effect of fuel lean reburning on $NO_X/CO$ reduction in LPG flame. Experiments were performed in flames stabilized by a co-flow swirl burner, which was mounted at the bottom of the furnace. Tests were conducted using LPG gas as the reburn fuel as well as the main fuel. The effects of reburn fuel fraction and injection location of the reburn fuel were studied when the fuel lean reburning system was applied. The paper reports data on flue gas emissions and temperature distribution in the furnace for a wide range of experimental conditions. At steady state, temperature distribution and emission formation in the furnace have been measured and compared. This paper makes clear that in order to decrease both NOx and CO concentrations in the exhaust when the fuel lean reburning system was adapted, it is important that the control of some factors such as initial equivalence ratio, reburn fuel fraction and temperature of reburn fuel injection region. Also it shows the fuel lean reburning is also effective method to reduce NOx as much as reburning.

• 대한기계학회논문집
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• 제19권3호
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• pp.763-770
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• 1995

Gas flow characteristics within the cylinder is important factors in impoving lean combustion stability. This paper shows the effects of various flow fields generated by a swirl control valve(SCV) on combustion process in a 4-valve spark ignition engine. An impulse swirl/tumble meter was used to elucidation the steady-state flow characteristics, and a rotating grating type LDV was developed to measure the mean velocity and tunbulence intensity in relation to the crank angle. These methodologies were applied to clarify the correlation between gas flow characteristics and combustion stability at a lean air fuel ratio. An analysis of the correlation revealed the gas flow conditions required to optimize a lean-burn system.

• 지식경영연구
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• 제11권4호
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• pp.21-39
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• 2010

Recommender system is a core component of e-commerce. Correspondingly, metrics to evaluate the system performance have been developed and applied. However, even though we have lots of applications that have tried to adopt recommender systems, the dearth of successfully installed recommender systems for more than a decade leads us to a skeptical thinking that current metrics do not sufficiently indicate the recommender system success in business viability point of view. Hence, the purpose of this paper is to reconfigure measures for recommender system success. Adopting DeLone and McLean's amended model of information system success as the underlying framework, content analysis with intellectual properties on recommender systems was conducted to modify the currently used metrics. Then a model of recommender system success is proposed based on the newly identified metrics are compared with traditional metrics.

• 품질경영학회지
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• 제48권3호
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• pp.381-393
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• 2020

Purpose: The purpose of this study was to find useful solutions by analyzing causes and results about defects on mechanical drawing notes and provide an automated tool with solutions to mechanical engineers. Methods: The collected data for defects on mechanical drawing notes were from ongoing development and mass production projects. Various measurement methods were used based on the Lean 6 Sigma analysis such as Process analysis, C&E diagram and some statistical analysis. Results: The results of this study are as follows; The results of the Lean 6 Sigma analysis, the validity of the selected indicators for improving drawing notes quality was verified through the verification of cause variables. The strategy established to improve the mechanical drawing notes was reflected as an automated program, and the defects were within a manageable range and achieved target Sigma level. Conclusion: Through the application of the "Mechanical drawing notes automation tool", it is expected to resolve the "Voice of Customer, VOC" and "Voice of Business, VOB".

• 한국분무공학회지
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• 제9권2호
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• pp.9-17
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• 2004

The performance characteristics of lean burn system in gasoline engine are mainly affected by the air-fuel mixture in cylinder, gas exchange process of manifold system, exhaust emission of engine, and the electronic engine control system. In order to obtain the effect of performance factors on the optimum conditions of lean burn engine, this study deal with the behavior of mixture formation, gas flow characteristics of air, flow and evaporation analysis of spray droplet in cylinder, vaporization and burning characteristics of lean mixture in the engine, and the control performance of electronic engine control system. The optimum flow conditions were investigated with the swirl and tumble flows in the combustion chamber with swirl control valve. The performance characteristics and optimum condition of flow field in intake system were analyzed by the investigation of inlet flow of air and combustion stabilization on cylinder.