• Title/Summary/Keyword: Lean Production

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A Study on the Development of Stoichiometric Direct Injection Gasoline Engine by Homogeneous Charge (균일 혼합기를 이용한 이론 공연비 직접분사 가솔린 엔진 개발에 관한 실험적 연구)

  • 이내현;유철호;최규훈
    • Transactions of the Korean Society of Automotive Engineers
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    • v.6 no.2
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    • pp.32-42
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    • 1998
  • Lean burn gasoline engine is recognized as a promising way to meet better fuel economy. Lean burn engine is classified into port injection and direct injection(DI), DI is more active technique for improving fuel economy with ultra-lean operation, Nowadays, port injected lean burn engine has been produced by many Japan maker. Also, DI engine is also possible for production owing to improvement in control technique of spray, flow air fuel ratio. DI engine uses either homogeneous stoichiometric mixture or stratified mixture by controlling injection timing to be early or late respectively. HM(homogeneous mixture) is worse than SM(stratified mixture) in view of ultra-lean operation in partical load and Nox reducion by using EGR control. But, HM has advanteges in cold starting and emission reduction during transient operation, This paper describes experimental variables and bench test results of HM GDI engine.

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EFFECT OF GINGER RHIZOME EXTRACT ON TENDERNESS AND SHELF LIFE OF PRECOOKED LEAN BEEF

  • Kim, K.J.;Lee, Y.B.
    • Asian-Australasian Journal of Animal Sciences
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    • v.8 no.4
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    • pp.343-346
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    • 1995
  • The inclusion of crude ginger rhizome (zingiber officinale) extract at 0.5 to 1.0% (v/w) in the marination of marginally acceptable lean beef improved meat tenderness by 20-30% in the absence of 2% salt and by 35-45% in the presence of 2% salt. Ginger extract also retarded the development of rancidity and increased shelf-life of precooked lean beef two-fold in saran-wrap (no vacuum) storage at $4^{\circ}C$. Ginger rhizome improves the palatability and acceptability of lean beef from carcasses of marginal quality. It is particularly beneficial for the preparation of pre-cooked ready-to-eat beef products that are not vacuum-packaged.

As strategy of Management Innovation, A Study on Analysis and Comparison Plan of Six Sigma, Lean and Theory of Constraints (기업의 경영혁신 전략 적용사례 및 비교분석에 관한 연구)

  • Cho, Tae-Yeon
    • Proceedings of the Safety Management and Science Conference
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    • 2011.04a
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    • pp.541-552
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    • 2011
  • Many of Korea major companies have appled as strategy of management innovation Six Sigma, Lean and Theory of Constraints. Six Sigma has mainly focused to reduce variation. Lean has mainly focused to reduce wastes and Theory of Constraints has mainly focused that bottleneck of constrains production and sales. This bottleneck is caused by constraint resources and it should be the main role of manager to explore constraint resource. Although their mainly focus are different, they are used to improve productivity and quality. In this paper, as strategy of management innovation, study on analysis and comparison plan of Six Sigma, Lean and Theory of Constraints. From the literature survey and application cases, it is suggested and discussed that how to plan of application as strategy of management innovation successfully. The suggested plan of application could be a good guideline that it could be a apply of companies.

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Feasibility Study in Construction Materials using Value Stream Analysis - Focused on Mechanical Works - (가치흐름분석을 통한 건설자재의 공장화생산 타당성 검토 - 건축공사의 기계설비 공사를 중심으로 -)

  • Seo Chang-Yong;Kim Chang-Duk
    • Proceedings of the Korean Institute Of Construction Engineering and Management
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    • autumn
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    • pp.389-392
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    • 2002
  • Local Mechanical work is researched which spending unnecessary labors and time due to unnecessary material accumulation and fabricated on site. Accordingly, this study analyzes the work process of mechanical equipments by Lean Production principles. Value Stream Analysis(VSA) uncovers waste factor of the existing method and manufactory production method using Value Stream Mapping(VSM). In the results, this study presents improvement of the existing method problems and negative factors of manufactory production.

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Development and Implementation of Chain Metrics for Obtaining Lean Overall Equipment Effectiveness Using Availability Measures (시간가동률 척도에 의한 Lean OEE의 연계지표 개발 및 적용)

  • Choi, Sung-Woon
    • Journal of the Korea Safety Management & Science
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    • v.14 no.2
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    • pp.147-158
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    • 2012
  • This paper aims to develop a new chain metrics for obtaining lean Overall Equipment Effectiveness(OEE) and present implementation strategy which considers the properties for Total Productive Maintenance(TPM) to reduce machine losses, Performance Analysis and Control(PAC) to reduce labor losses, Lean Production System(LPS) to reduce floor wastes, and Theory of Constraints(TOC) to minimize the problem of Capacity Constrained Resource(CCR). The study reviews the related literatures and reformulates the structure of machine losses, labor losses and field wastes. The research also develops the integrated productivity metrics according to time, units, reliability and maintainability. It is found that the study develops the actual productivity measure in terms of efficiency, effectiveness and standard productivity. In addition to that, it outlines and develops by using the integrated LPS and TPM, lean OEE measures such as Time Based Productivity(TBP), Unit Based Productivity(UBP), and Reliability & Maintainability Based Availability(RMBA). Implication examples are proposed to make it easier and available for practioners to understand the implementation strategies about TPM OEE, lean OEE and TOC OEE. Futhermore related to other studies, the research contributes to create a new chain productivity measures to clear the interrelationship concepts of productivity, efficiency and effectiveness. Moreover the paper develops the enhanced OEE measures by integration of TPM, PAC, LPS and TOC with the perspective of schedule, throughput, reliability, maintainability and availability.

Web-based Distributed Lean Construction Information System;Introduction of Lean Construction Research Center (웹 기반 분산형 린건설 정보시스템 개발;연구단 소개)

  • Yoon, You-Sang
    • Proceedings of the Korean Institute Of Construction Engineering and Management
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    • 2006.11a
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    • pp.221-228
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    • 2006
  • To reform and improve the productivity of construction industry, 1) it should be encouraged to improve the construction production process and 2) it is required to enhance reliability of construction information based on the systematic thinking process. To promote the information reliability created during construction production process, Lean Construction Research Center(LRC2) is developing a supporting system to improve processes of design/supply/construction phase, functioning to efficiently manage the information created at each phase and developing a web based construction information system that provides result management/decision making support/knowledge based information services.

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Improvement of Human Motivation in Lean Construction Implementation (린 건설 수행에 따른 인적자원의 동기유발)

  • Kim, Dae-Young
    • Korean Journal of Construction Engineering and Management
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    • v.7 no.3 s.31
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    • pp.130-137
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    • 2006
  • Since Lean Construction has been introduced in 1992, much research is in progress to popularize lean concepts and principles. Most research focuses on developing lean concepts and tools and strengthening the limited domain of instrumental rationality and technical efficiency. However, the basic concepts of human resource management seem to be ignored by those who advocate lean production. Thus, the lean construction research related to human resource management must be once considered for popularization and activation of lean construction at the beginning stage in the domestic construction industry. Because human resources have a major influence on lean implementation and its success, especially at the beginning stage of lean construction. This paper considers the human resource requirements for the implementation of lean construction in the USA construction industry. The results from the study will provide the foundations to adapt lean construction into the domestic construction industry. Consequently, the study found that lean construction could improve the capability of human resource and human motivation if effectively implemented in the construction sites. Since lean construction emphasizes and focuses on improvement of relationships among project participants, constant application to human resource management is crucial for successful lean implementation.

A Numerical Study on the Lean-Rich Interaction of Methane/Air Flames (희박-과농 메탄 화염의 상호작용에 관한 수치해석적 연구)

  • Lee, Seung-Dong;Jeong, Seok-Ho
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.20 no.1
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    • pp.377-383
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    • 1996
  • Interaction of flames in a lean-rich concentration field is studied numerically adopting a counterflow as a model problem. Detailed kinetic mechanism is adopted in analyzing the structure of various type of flames which can be found in lean-rich interaction. Flow field is simplified to quasi one-dimensional by using boundary layer approximation and similarity formulation. Triple flames are identified and its structure shows that a diffusion flame is located in the middle of two premixed flames. Such a diffusion flame is formed by $H_2$ and CO generated from the rich premixed flame and $O_2$ leaked from the lean premixed flame. The flame position can be identified either from the hydrogen production rate or the heat release rate. Transition from single diffusion flame to triple flame is observed as degree of premixing is increased.

Analyzing Site Reliability for Residential, Civil and Plant Projects using Lean Construction Principles (린 건설에 기초한 국내 건설 공사의 시공 계획 신뢰도 평가 및 분석)

  • Koo, Bonsang
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.28 no.5D
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    • pp.655-664
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    • 2008
  • Lean Construction recommends implementing site production management by measuring the reliability of daily production tasks, collecting the causes for failure of incomplete tasks, and identifying problems in the existing process based on the collected data. Although many research projects have been performed to introduce Lean Construction in Korea, there are not many cases in which day-to-day site production operations has been stringently evaluated based on such methods. This paper introduces three cases in which such techniques were implemented on a residential, civil infrastructure and plant project. On each project, process maps were created with the superintendents and daily production meetings were held for two weeks. Consequently, the average PPC for the three projects was 79% for PPC and 16% for PAT. In addition, the majority of the failures were due to 'Directive/Plan' and 'Prerequisites.' The results show that project stakeholders (owners, contractors, etc.) lack the ability to plan ahead and keep to their plans, and also lack the capability to synchronize workflow between themselves. The results also reveal that project participants need to be more proactive in solving process problems on site and also need to be better educated in Lean concepts and methodologies.

Practitioners' Perception on Relationship between Production Planning and Waste Occurrence in Construction Projects

  • Khanh, Ha Duy;Kim, Soo Yong
    • Journal of Construction Engineering and Project Management
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    • v.4 no.3
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    • pp.1-12
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    • 2014
  • Construction management has been suffering from many problems, which need to be solved or better understood. Most of construction projects have not achieved efficiency as expected. In this context, waste was also considered as a problem of efficiency decrease, and poor production planning was considered as a cause for waste. This study was conducted on the basis of waste concepts and production planning processes based on the philosophies of Lean Construction. A survey to find out the relationship between them was carried out through questionnaire, which was answered by experienced people in construction projects. The results have shown that frequency of wastes occurrence is quite high, and production planning processes are superficially performed in construction phase. There is a significant negative relationship between production planning and waste occurrence (r = -0.262). Weekly Work Plan (WWP) is the most dominant plan for waste control with seventeen in total of nineteen waste factors, and phase plan is the most dominant plan for two remaining waste factors. A case study was adopted to validate the relationship between production planning and waste occurrence. The results showed that the better the project was planned, the fewer the waste would occur on construction sites.