• Transactions of the Korean Society of Mechanical Engineers B
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• v.39 no.9
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• pp.727-734
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• 2015

Recently, because of the increased oil prices globally, there have been studies investigating the improvement of fuel-conversion efficiency in internal combustion engines. The improvements realized in thermal efficiency using lean combustion are essential because they enable us to realize higher thermal efficiency in gasoline engines because lean combustion leads to an increase in the heat-capacity ratio and a reduction of the combustion temperature. Gasoline direct injection (GDI) engines enable lean combustion by injecting fuel directly into the cylinder and controlling the combustion parameters precisely. However, the extension of the flammability limit and the stabilization of lean combustion are required for the commercialization of GDI engines. The reduction characteristics of three-way catalysts (TWC) for lean combustion engines are somewhat limited owing to the high excess air ratio and low exhaust gas temperature. Therefore, in the present study, we assess the reaction of exhaust gases and their production in terms of the development of efficient TWCs for lean-burn GDI engines at 2000 rpm / BMEP 2 bar operating conditions, which are frequently used when evaluating the fuel consumption in passenger vehicles. At the lean-combustion operating point, $NO_2$ was produced during combustion and the ratio of $NO_2$ increased, while that of $N_2O$ decreased as the excess air ratio increased.

• Journal of the Korea Safety Management & Science
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• v.8 no.4
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• pp.239-247
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• 2006

This paper is to propose new features and models for process innovation after classifying in three categories ; conventional six sigma, lean six sigma and 3rd generation six sigma. First considering two project types which are bottom-up and tod-down, DMAIC process is linked up with QC story 15 steps. Secondly, I present Koreanized lean six sigma model using Japanese production technology and principles. Lastly, this paper also depicts a new 3rd generation six sigma model utilizing MBNQA management quality system.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.1031-1035
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• 2008

The importance of the more efficient cogeneration system is emphasized. Also the more clean energy is needed at recent energy system. The cogeneration system using Lean burn engine is more preferred to the system using Rich burn engine because of the electrical efficiency. Although the cogeneration system using Lean burn engine is economically preferred, because of the NOx emission level, the system using Rich burn engine with 3-way catalyst can only be used in Korea. The NOx regulation level is 50ppm at oxygen level 13%. The cogeneration hybrid system is consist of Lean burn gas engine, afterburner, boiler, economizer, DeNOx catalyst, combustion catalyst, absorption chiller, cooling tower and grid connection system. The system was accurately evaluated and the result is following ; 90% total efficiency, below 10ppm NOx, 50ppm CO, 25ppm UHC. The cogeneration hybrid system can meet the NOx level and exhaust gas regulation. It can achieve the clean combustion gas and efficient cogeneration system.

• International Journal of Highway Engineering
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• v.14 no.5
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• pp.21-29
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• 2012

PURPOSES: This study is to investigate the mechanical performance of the fiber reinforced lean concrete with respect to different types of fibers. METHODS: Increased vehicle weight and other causes from the exposed conditions have accelerated the deteriorations of road pavement. A new multi-functional composite pavement system is being developed recently in order to extend service life and upgrade the pavement. A variety of tests were conducted before and after hardening of the concrete. RESULTS: From the test results, it was found that the use of different types of fibers did not affect the compressive strength development. This might be due to the inherent property of the lean concrete. When steel fibers were used relatively greater flexural strength and flexural fracture toughness were developed. Also addition of fly ash by replacing a part of Portland cement the fracture toughness was slightly increased. CONCLUSIONS: It has been known that the addition of fibers and use of mineral admixture can be positively considered in the development of multi-functional composite pavement system as its required mechanical performance is obtained.

• 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.

• Journal of KIBIM
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• v.8 no.4
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• pp.23-33
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• 2018

Recently, the industry actively adopts the cutting-edge technologies of the fourth industrial revolution and uses them to enhance the productivity and service of mass-customization. The manufacturing industry is creating new processes and business models by achieving digital transformations through a lean start-up approach aimed at achieving the highest customer satisfaction with minimal resources. Although attempts are made to manufacture the building by introducing the latest technology in architecture, it is applied sporadically, not as an integrated system, in the entire phase of the architectural project. This paper analyzes the changes in the construction industry through the application of core technologies of the fourth industrial revolution. Design processes are analyzed for the digital transformation of the construction industry by case study of advanced architectural design practice. A novel design concept model 'Architectural lean startup' is proposed by combining the architectural process and the lean start up method. Through the design of the bus stop based on the architectural lean startup concept, it is confirmed that the designer repeats the 'Generate-Test-Analysis' to develop the design and generate the final result.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.4
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• pp.517-527
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• 2021

While the two principles of lean manufacturing and time-driven activity-based costing (TDABC) have been established out of multiple incentives and do not follow the same particular targets, there is substantial commonality between them. In these conditions, the supply management of a multi-product system needs a rigorous production model to minimize costs. In this sense, this paper proposes an interactive model with the consideration of optimizing product-mix decisions using both lean development tools and TDABC. This paper proposes a qualitative approach using the case study of the Iraqi state company for battery production. The suggested model decreased manufacturing time and costs, along with some substantial reduction in idle production capacity by 26 percent in 2019, based on the findings of the case study. On the other hand, the proposed model gives two side advantages: an efficient division of costs on goods due to the use of time spent as a cost factor for products and cost savings due to the introduction of the lean manufacturing approach that reduces all additional costs and increases product-mix decisions. Furthermore, the analytical data gathered here suggests that the incorporation of lean management concepts and TDABC has a strong and important influence on product-mix decisions.

• Journal of Biomedical Engineering Research
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• v.28 no.5
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• pp.628-635
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• 2007

We studied the effect of vibratory stimulations of different leg muscles, tibialis anterior(TA) and triceps surae(TS), and plantar zones in ten healthy subjects during 1) quiet standing, 2) forward lean of body, 3) backward lean of body, 4) right lean of body, and 5) left lean of body. The experiments were performed on the force platform. The effect of vibration were measured by monitoring the area of COP(Center of pressure) sway. The subjects wore a vibratory stimulation system on foot and ankles and were given the instruction not to resist against the applied perturbations. The results show that all vibratory stimulations to lower limb muscles and plantar zones reduced the COP sway area. This reduction of the COP sway area occurred also in partial vibratory stimulations during quiet standing. In forward lean of body, vibratory stimulations to TA reduced the COP sway area. During backward lean of body, vibratory stimulations to TS reduced the COP sway area. When the subject was tilted right, vibratory stimulations to left plantar zone reduced the COP sway area. During left lean of body, vibratory stimulations to right plantar zone reduced the COP sway area. Thus, the influence of vibratory stimulations to leg muscle and plantar zones differed significantly depending on the lean of body. We suggest that the vibration stimuli from leg muscles and plantar zones could be selectively used to help maintaining postural balance stable.

• Convergence Security Journal
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• v.8 no.1
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• pp.101-108
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• 2008

This research focuses on the process improvement of port logistics by using Lean methodology. On the one hand, we firstly analyze the current situation and weakness of the processes in port logistics, and then re-design the current processes by the principles of Lean discipline. Based on the appropriately changed processes, the improvement scheme of port logistics will be figured out. On the other hand, we construct the port logistics system by implementing the improved processes. The port logistics' processes accomplished in steel company will be further assorted and identified. The relationship of wharves process, operational process, shipping process, construction process, quality process, and purchasing process are also defined. Every process has been improved by Lean Tools in order to analyze the value added or non-value added processes, to improve the service level, and to reduce the cycle time, inventory, changing time, re-working and waste. Based on above, the appropriate environment that is suitable to Lean process of port logistics will be established and the modeling that can help to implement the improvement scheme will be figured out.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.10 no.5
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• pp.63-71
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• 2015

Lean six sigma has to be utilized considering irrational system or defects based on features of organization beforehand. Otherwise, it won't improve anything but burden another heavy responsibilities to the people in charge. Therefore, a survey was conducted in addition to a literature review and a case study about lean six sigma to verify effective deployment method for lean 6sigma tools. The survey was conducted across for 96 interviewees who have MBB or BB was selected from 15 companies which have been running six sigma projects over 10 years and SPSS 16.0 was used for verifying reliability and validity of the research. In conclusion, some issues occurred in the process of six sigma projects were identified and effective deployment method of lean six sigma tools by integrating lean manufacturing into 6sigma were suggested based on those issues.