• 한국자동차공학회논문집
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• 제22권3호
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• pp.148-156
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• 2014

This study is a follow-up study of "Development of Plasma Ignition System" was presented at the 2013 KSAE spring conference. This study compares lean limit of conventional ignition system with plasma ignition system on constant volume combustion test & Engine Combustion test.

• 대한안전경영과학회지
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• 제17권2호
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• pp.97-106
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• 2015

System is the organization of hardware, software, personnel and facilities needed to perform a designated function within a stated environment with specified results. The trend of modern systems is getting more complex and larger. The system is necessary for modern society but the minor malfunction of the system can result the enormous human and material losses. Recently it is being heightened the concern for system safety and required to be built and applied Safety Engineering standard Guideline for safety of complex and large-sized system. This paper describes the System Engineering Process model integrated with Safety Engineering and the establishment of standard safety guidelines for safety of product development using DMADOV Methodology of the Lean 6 Sigma.

• 한국자동차공학회논문집
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• 제23권6호
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• pp.650-655
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• 2015

A high energy ignition system is essential for lean burn or high EGR gasoline engine, which is getting more and more interest to improve fuel economy. The high energy ignition systems comprise plasma jet, laser beam, corona discharge and so on. In this study, a high energy ignition system using corona discharge is developed and tested in a constant volume combustion chamber. The developed system shows extension of lean limit of propane-air mixture and enhencement of combustion speed. Various shape of corona discharge plugs are also tested and compared in this study.

• International Journal of Advanced Culture Technology
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• 제7권1호
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• pp.128-132
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• 2019

This paper is to explore the success factors of the online public grievance redressal system in the Nepal. It empirically tests the conceptual path model developed by DeLone and McLean which consists of six social perception variables with regard to citizen's intention to use the system. The estimates from 577 respondents support all the 13 hypotheses generated from D&L model. People's attitude and social norms are the two most important factors on the continuous usage of the system. It is suggested that the social factors are as much important as technological aspects when it comes to the e-government implementation. It is also suggested that the government should pay more attention to human factors in upgrading the design and development of e-grievance system in the foreseeable future.

• 국제학술발표논문집
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• The 2th International Conference on Construction Engineering and Project Management
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• pp.41-49
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• 2007

GS E&C had developed construction management system, PMS which is based on EVMS in 1997. Recently, TPMS has developed for effective construction management through applying daily schedule management and JIT on materials, labors, equipments focusing field work. TPMS realizes "Shielding" and "Make-Ready Process" which are the main concept of Lean construction. Through this system, it can manage and plan daily field work, support the field work related material, labor, and equipment planning, and minimizes the non-valuable process. This paper introduces the concept of TPMS, and through established system, it can lead the construction culture and raise the competitive power of construction industry

• 한국분무공학회지
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• 제9권4호
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• pp.46-52
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• 2004

An LPG engine (KL6i) for heavy duty vehicle has been developed using liquid phase LPG injection (LPLi) system, which has regarded as one of next generation LPG fuel supply systems. For the KL6i engine, lean burn technology was introduced to minimize the thermal loading and NOx emissions due to an increase of the engine power. In this work, injection timing and piston bowl shape were investigated for the stabilization of lean burn characteristics. Experimental results reveals that fuel stratification induced by these parameters is most effective strategy to extend lean combustion limit in the LPLi system.

• 산업노동연구
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• 제17권1호
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• pp.1-36
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• 2011

대안적 작업조직을 둘러산 다양한 주장과 논쟁이 단위조직 사례연구를 토대로 이론적 개념적 차원에서 제기되어 왔으나 정작 노동자 관점에서의 양적 검증은 상대적으로 부족했다. 이 글은 한국직업능력개발원의 인적자본 기업패널 제조업 자료를 이용하여 대안적 작업조직의 대표적 형태로써 테일러 방식과 린 방식, 자율팀 방식을 유형화한 후 각각 조직의 재무적 성과와 노동자 성과에 어떤 영향을 미치는지 분석하고자 하였다. 특히, 국내 제조업의 경우 린 방식의 대표적 특성인 QC, 제안활동 등의 개별참여 관행이 확산되고 있다는 측면에서, 린 방식을 준거로 사회기술체계의 특성을 고려한 자율팀과 테일러 방식을 비교 분석하였다. 분석 결과, 대안적 작업조직으로써 린 방식과 자율팀 방식이 테일러 방식에 비해 조직성과 뿐만 아니라 노동자 개인의 성과측면에도 보다 긍정적인 것으로 파악되었다. 그러나 린 방식과 자율팀 방식간 비교에서는 조직성과에 미치는 영향은 통계적으로 유의한 차이를 보이지 않은 반면, 노동자 개인의 성과로써 노동시간, 소득, 직무만족도, 조직몰입의 모든 결과변수에 대해 린 방식이 자율팀 방식에 비해 일관된 부정적 영향을 미치는 것으로 파악되었다. 린 방식이 품질개선과 조직성과 향상을 위한 우월한 작업조직이라는 주류적 공감에도 불구하고, 그와 같은 기제의 이면에는 드러나지 않았던 노동자 개인의 성과가 훼손되었을 가능성을 시사하였다.

• 한국자동차공학회논문집
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• 제22권6호
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• pp.96-103
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• 2014

Liquefied Petroleum Gas(LPG) has attracted attention as a alternative fuel. The lean-burn LPG direct injection engine is a promising technology because it has an advantage of lower harmful emissions. This study aims to investigate the effect of combustion strategy and excess air ratio on combustion and emission characteristics in lean-burn LPG direct injection engine. Fuel consumption and combustion stability were measured with change of the ignition timing and injection timing at various air/fuel ratio conditions. The lean combustion characteristics were evaluated as a function of the excess air ratio with the single injection and multiple injection strategy. Furthermore, the feasibility of lean operation with stratified mixture was assessed when comparing the combustion and emission characteristics with premixed lean combustion.

• 대한안전경영과학회지
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• 제14권2호
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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.

• International Journal of Automotive Technology
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• 제6권6호
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• pp.591-598
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• 2005

A three-way catalyst system of a natural gas vehicle (NGV) has characteristics of higher fuel consumption and higher thermal load than a lean-bum catalyst system. To meet stringent emission standards in the future, NGV with the lean-bum engine may need a catalyst system to reduce the amounts of HC, CO and NOx emission, although natural gas system has low emission characteristics. We conducted experiments to evaluate the conversion efficiency of the NOx reduction catalyst for the lean-burn natural gas engine. The NOx reduction catalysts were prepared with the ${\gamma}-Al_{2}O_3$ washcoat including Ba based on Pt, Pd and Rh precious metal. In the experiments, effective parameters were space velocity, spike duration of the rich condition, and the temperature of flowing model gas. From the results of the experiments, we found that the temperature for maximum NOx reduction was around $450^{\circ}C$, and the space velocity for optimum NOx reduction was around $30,000\;h^{-1}$ And we developed an evaluation model of the NOx reduction catalyst to evaluate the conversion performance of each other catalysts.