• International Journal of Automotive Technology
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• v.4 no.4
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• pp.193-201
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• 2003

The problem of brake judder is typically caused by defects of quality manufacturing. DFSS (Design for six sigma) is a design process for quality improvement. DFSS will result in more improved but less expensive quality products. This paper presents an implementation of DFSS for quality improvement of the brake judder of heavy-duty trucks. Carrying out 5 steps of DFSS, the major reasons for defects of quality are found. The numerical approximation of the brake system is derived by means of the response surface method. Its quality for brake judder is improved by using the sigma based robust design methodology. Results are compared between the conventional deterministic optimal design and the proposed sigma based robust design. The proposed one shows that manufacturing cost may increase as the quality level increase. The proposed one, however, is more economical in aspect of the overall cost since the probability of failure dramatically goes down.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.33 no.4
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• pp.193-200
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• 2010

In this study, we took the census of the project satisfaction level of the employees who have participated in Six Sigma projects. We divided and measured the project satisfaction by the steps of performing the project (team building, execution, ownership and support step). We performed the analysis of variance to show the main factors of project satisfaction level, and the tests of homogeneity to know the relationship the business parts and among the job positions each. The results of analysis showed that the satisfactions of the team building and execution step were significant.

• Journal of Korean Society for Quality Management
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• v.27 no.4
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• pp.266-279
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• 1999

Today, Companies are facing the harsh realities of a competitive environment. This is no time for revolutionary change. Instead, Companies are instituting revolutionary change meant to have impact within a very short time frame. Bold steps are required to lead the industry into a future of improved efficiency and significant productivity gains. GE, as well as Intel, Motorola, and other companies adopted a program called Six Sigma, in order to make fundamental changes in the way the company operated to fulfill customers'expectations. Six sigma reduces the occurrence of defects from a 3 sigma level of 66,800 defects per million to a 6 sigma level-less than 4defects per million. The goals and metrics of the company's Six Sigma process clearly have had a positive effect on customer satisfaction and customer perception of the company.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1334-1337
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• 2007

A steel pallet to carry lighter logistic articles is developed based on the DFSS(design for Six Sigma) methodology. Combining the conventional DFSS(Design For Six Sigma) methodology with that of VE(Value Engineering) is the novel feature of this paper to achieve maximum cost reduction. In this paper, systematical steps to achieve the required structural spec's are presented by conventional DMEDI(Define-Measure-Explore-Develop-Implement) process. To imply the target costing, evaluation of functions consisting of the pallet has been performed by value methodology. Then best design concept is selected in the Explore step, following structural optimization utilizing FEM. Finally the performance of prototype is investigated by pilot test in the Implement step. The developed steel pallet is being commercialized in the fields of automated ware house.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.05a
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• pp.199-202
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• 2005

In this paper, the six sigma scheme is employed together with the rigid-viscoplastic finite element method to obtain the optimal metal flow lines in hot press forging. In general, the six sigma process is consisted of following five steps : define, measure, analyze, improve and control. Each step Is investigated in detail to meet customer's requirements through improvement of product quality. A forging simulator, AFDEX-2D, is used for analysis of the metal flow lines of a multi-stage hot forging process under various conditions of major factors, determined at each step of the six sigma process. The analyzed results are examined in order to reveal the effects of major factors on the metal flow lines and the formed shapes. The effects are used to find an optimal process and the optimal process with die is devised and tested. The comparison between required metal flow lines and experiments shows that the approach is effective for optimal process in hot forging design considering metal flow lines.

• MALSORI
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• no.41
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• pp.73-81
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• 2001

This paper reports the results of an experimental phonetic study of intonation contrasts perception by speakers of British English, Japanese and Russian. Six series of re-synthesized two-syllable rise-fall contours with manipulated parameters of the rise in the first and the fall in the second syllable were employed in the experiment. Modifications of pitch height were executed in 2 st steps, and of duration in 30ms steps. The subjects, who were native speakers of British English, Japanese and Russian, identified the sentence type of presented re-synthesized stimuli. The results of the experiments demonstrate overall similarity of the perception strategies across the three groups of subjects, especially regarding the thresholds of declarative' sentence type judgement. Non-declarative judgements are more language-specific. The results can be employed for the teaching of English, Japanese and Russian as foreign languages as well as for speech synthesis and recognition.

• Proceedings of the KSPS conference
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• 2000.07a
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• pp.139-148
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• 2000

This paper reports the results of an experimental phonetic study of intonation contrasts perception by speakers of British English, Japanese and Russian. Six series of re-synthesized two-syllable rise-fall contours with manipulated parameters of the rise in the first and the fall in the second syllable were employed in the experiment. Modifications of pitch height were executed in 2 st steps, and of duration - in 30ms steps. The subjects, who were native speakers of British English, Japanese and Russian, identified the sentence type of presented re-synthesized stimuli. The results of the experiments demonstrate overall similarity of the perception strategies across the three groups of subjects, especially regarding the thresholds of 'declarative' sentence type judgement. Non-declarative judgements are more language-specific. The results can be employed for the teaching of English, Japanese and Russian as foreign languages as well as for speech synthesis and recognition.

• Bulletin of the Korean Chemical Society
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• v.13 no.3
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• pp.311-314
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• 1992

A new monocyclic ${\beta}-lactam$ analogue, sodium (3R,4S)-3-[2-(2-aminothiazol-4-yl)-(Z)-2-methoxyi minoacetamido]-4-methoxymethyl-2-azetidinone-1- sulfonate (3) was synthesized from L-aspartic acid. Starting from L-aspartic acid, (S)-1-benzyl-4-benzyloxycarbonyl-2-azetidinone (7) was synthesized in four steps by following the established procedures and converted into (3R,4S)-3-amino-1-t-butyldimethylsilyl-4-methoxym ethyl-2-azetidinone (13) in six steps. Acylation of the amino group of 13 with $2-amino-{\alpha}$ -(methoxyimino)-4-thiazoleacetic acid, desilylation, and sulfonation with sulfur trioxide-pyridine complex followed by ion exchange afforded sodium (3R,4S)-3-[2-(2-aminothiazol-4-yl)-(Z)-2-methoxyi minoacetamido]-4-methoxymethyl-2-azetidinone-1- sulfonate (3). Antibacterial activities of this ${\beta}$ -lactam compound 3 were, however, found to be quite low compared to cefotaxime.

• Transactions of Materials Processing
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• v.14 no.9 s.81
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• pp.798-803
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• 2005

In this paper, the six sigma scheme together with the rigid-viscoplastic finite element method is employed to obtain the optimal metal flow lines of a hot forging according to the six sigma processes, i.e., five steps such as define, measure, analyze, improve and control. Each step is investigated in detail to meet customer's requirements through improvement of product quality. A forging simulator is used for analysis of the metal flow lines of the hot forging, manufactured by a hot press forging machine, under various conditions of major factors determined at each step. The analyzed results are examined in order to reveal the effects of major factors on the metal flow lines and the formed shapes. The effects are then used to find an optimal process and the optimal process with die is devised and tested. The comparison between the required metal flow lines and the experiments shows that the approach is effective for optimal process design in hot forging considering metal flow lines.

• International Journal of Advanced Culture Technology
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• v.7 no.4
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• pp.163-171
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• 2019

Purpose: Purpose: The National Safety Experience Center Establishment and Reinforcement Project Management Guidelines, established to build a national safety experience center that is central to practicing education on disasters and safety accidents, requires that appropriate experience training programs be in place. However, due to the lack of classification grounds for the six areas of disaster•safety accidents presented by the Ministry of Public Administration and Security, and the mortality statistics necessary for establishing sectors have accumulated for over a decade, they are based on this. Our purpose is to standardize classification of sectors belonging to each area. Methods: We will divide disaster•safety accidents into 6 areas by three steps, and the grounds for 6 areas of accidents are presented. The 15 external causes other than the disease since 2009 has been proposed by The National Statistical Office. Therefore on the basis of these causes, various sectors belonging to each area are classified. Results: We will divide all disaster•safety accidents into six areas through three logical separation stages, and the areas were systematically classified based on the 15 factors of death. In conclusion, we present the grounds for the classification criteria in the six areas, the transportation accident disaster area in three areas, the social infrastructure system area in four areas, the crime accident disaster area in four areas, the life safety accident area in four areas, we set up all disaster•safety accidents in six areas and finally standardize total 25 areas.