• Journal of the Korean Mathematical Society
• /
• v.45 no.3
• /
• pp.771-780
• /
• 2008

Let $M_C=\(\array{A&C\\0&B}\)$ be a $2{\times}2$ upper triangular operator matrix acting on the Hilbert space $H{\bigoplus}K\;and\;let\;{\sigma}_w(\cdot)$ denote the Weyl spectrum. We give the necessary and sufficient conditions for operators A and B which ${\sigma}_w\(\array{A&C\\0&B}\)={\sigma}_w\(\array{A&C\\0&B}\)\;or\;{\sigma}_w\(\array{A&C\\0&B}\)={\sigma}_w(A){\cup}{\sigma}_w(B)$ holds for every $C{\in}B(K,\;H)$. We also study the Weyl's theorem for operator matrices.

• Korean Management Science Review
• /
• v.28 no.1
• /
• pp.129-140
• /
• 2011

There is no doubt Six Sigma is an excellent concept to improve quality of product or service. However, limitations to Six Sigma's implementation process have been discovered that are related to Six Sigma's foundation in statistical methods. The limitations of Six Sigma are overcome by the advantages of a strategic CoP (Community of Practice). Therefore, this research tries to build a strategic CoP for implementing Six Sigma. The method for building a strategic CoP is suggested, and then a case study of a real company is presented.

• Journal of the Korea Safety Management & Science
• /
• v.10 no.3
• /
• pp.183-191
• /
• 2008

Many companies desperately effort to find out more effective management method to survive in keen competition. Jack welch of past GE's CEO had said that an excellent result of today's GE management is thanks to Six sigma work. Many korean companies are introduced Six sigma method in their management since late 1993. Six sigma uses a set of strategies, statistics and methods to improve the processes we use to do everything from designing to manufacturing a product from marketing products and services to providing business information to our internal and external customers. The purpose of this study is to overcome these problems and to help make an important decision in establishing introduction strategy by abstracting the reasons and success factors and result indices which are important sources for introducing Six sigma management.

• Journal of the Korean Chemical Society
• /
• v.7 no.4
• /
• pp.238-244
• /
• 1963

Linear relationships between thermodynamic parameters, ,${\Delta}{\Delta}H^{\neq}=a{\sigma}+b{\Delta}{\Delta}S^{\neq}$, and $\Delta{\Delta}F^\neq=a\sigma+(b-T)\Delta{\Delta}S^\neq$, which were derived in the previous report have been tested with 57 reactions from literature. Linearities of plots $\Delta{\Delta}H^\neq-a\sigma$ vs. $\Delta{\Delta}S^\neq$ were generally good and the average correlation coefficient was 0.983 and the average of standard deviations from regression lines was 0.11. For 15 out of 57 reactions, Hammett plots were unsatisfactory and most of the reaction did not satisfy the Leffler equation. The general applicability of the new equations has been confirmed by the analysis of each reaction for which existing equations failed to correlate.

• Research in Plant Disease
• /
• v.30 no.2
• /
• pp.148-156
• /
• 2024

Ralstonia pseudosolanacearum, a plant pathogenic bacterium that can survive for a long time in soil and water, causes lethal wilt in the Solanaceae family. Sigma S is a part of the RNA polymerase complex, which regulates gene expression during bacterial stress response or stationary phase. In this study, we investigated the role of sigma S in R. pseudosolanacearum under stress conditions using a rpoS-defective mutant strain of R. pseudosolanacearum and its wild-type strain. The phenotypes of rpoS-defective mutant were complemented by introducing the original rpoS gene. There were no differences observed in bacterial growth rate and exopolysaccharide production between the wild-type strain and the rpoS mutant. However, the wild-type strain responded more sensitively to nutrient deficiency compared to the mutant strain. Under the nutrient deficiency, the rpoS mutant maintained a high bacterial viability for a longer period, while the viability of the wild-type strain declined rapidly. Furthermore, a significant difference in pH was observed between the culture supernatant of the wild-type strain and the mutant strain. The pH of the culture supernatant for the wild-type strain decreased rapidly during bacterial growth, leading to medium acidification. The rapid decline in the wild-type strain's viability may be associated with medium acidification and bacterial sensitivity to acidity during transition to the stationary phase. Interestingly, the rpoS mutant strain cannot utilize acetic acid, D-alanine, D-trehalose, and L-histidine. These results suggest that sigma S of R. pseudosolanacearum regulates the production or utilization of organic acids and controls cell death during stationary phase under nutrient deficiency.

• Journal of Korean Academy of Nursing
• /
• v.32 no.6
• /
• pp.878-887
• /
• 2002

This study was to explore lived experience of middle-aged women with aging. The ultimate purpose of this inquiry was to discover the essence of middle-aged women's experience of aging and to promote understanding. Method: This inquiry was performed by using Van Manen's hermeneutical phenomenological approach to make more plausible interpretation of experience. First-handed experiences were explored through multi-stage in-depth interview with 6 women aged between 40 and 64. Second- handed experiences were explored with text such as essay, novel, and photographs. Result: As the process of reflecting and analysing the data of experience were performed, essential themes were emerged: striking onset of event, discomfort and tired body and mind, everything in ones mind, age of harvest gaining much more than loss. Conclusion: This inquiry would be a cornerstone for humanistic nursing care for the mid-aged women.

• Journal of the Korean Society of Industry Convergence
• /
• v.13 no.1
• /
• pp.49-54
• /
• 2010

Lean 6 sigma has recently been used to describe a management system which combines lean management and 6 sigma. The marriage between Lean manufacturing and 6 sigma has proven to be a powerful tool for cutting waste and improving the organization operations. Time and quality are the most important metrics in improving any company's production and profit performance. lean 6 sigma is a management innovation for improving production efficiency, process quality, cost reduction, investment efficiency and customer's satisfaction. in this paper, Advanced cell line is builded the home appliance goods of the LCD TV final assembly line of domestic company line, training the multi-skilled man and controlling the production information system based on Lean 6 sigma.

• Journal of Korean Society for Quality Management
• /
• v.34 no.3
• /
• pp.51-61
• /
• 2006

This paper is dealing with a 6 sigma application in chemical industries. The company is enterprise which produce PR that is semiconductor material. CTQ is consisted of thickness (Big Y$_1$) and EOP (Big Y$_2$). After 6 sigma improvement activity that thickness (Big Y$_1$) improved from 0.98 sigma to 2.80 sigma and EOP (Big Y$_2$, energy optimizer) improved from 1.53 sigma to 3.98 sigma. The effectiveness of financial scope reduced 58,200,000 won of COPQ. But there are some problems to enforce 6 sigma in small enterprises. First, it is a lack of complete charge manpower enforcing S sigma activity. Second, it is a lack of professional knowledge of project leaders. Third, the passion of sponsorship (champion) is a lacking. Nevertheless useful tool was certified so that 6 sigma achieves quality reform in small enterprises.

• Journal of Korean Society for Quality Management
• /
• v.31 no.2
• /
• pp.220-229
• /
• 2003

The methodology of Six Sigma originated at Motorola in the early 1980s is nowadays proved to be an effective way in Improving the quality. Many companies find adding Six Sigma to their current business system gives them all or almost all the elements of total quality management(TQM). However most companies where Six Sigma is implemented confront many difficulties in non-manufacturing parts such as transactional and administrative processes. In this paper we discuss distinct aspects of such non-manufacturing process, and investigate activating scheme of Six Sigma in those parts of industry.

• IE interfaces
• /
• v.16 no.spc
• /
• pp.60-64
• /
• 2003

This study proposes a method of implementing Six Sigma linking Lean approach and/or TOC(Theory of Constraints). A case study carried out in a PCB production line is examined to compare Lean Six Sigma and TOC Six Sigma. Implementing guidelines are given to achieve the whole company's optimum.