• Journal of the Korean Mathematical Society
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• v.34 no.3
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• pp.633-651
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• 1997

For a non-degenerate symmetric bilinear form $\sigma$ on a finite dimensional vector space E, the Jordan algebra of $\sigma$-symmetric operators has a symmetric cone $\Omega_\sigma$ of positive definite operators with respect to $\sigma$. The cone $C_\sigma$ of elements (x,y) \in E \times E with \sigma(x,y) \geq 0$ gives the compression semigroup. In this work, we show that in the sutomorphism group of the tube domain over $\Omega_\sigma$, this semigroup has a UDL and Ol'shanskii decompositions and is exactly the compression semigroup of $\Omega_sigma$.

• Journal of Applied Reliability
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• v.1 no.1
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• pp.65-78
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• 2001

Recently, Six Sigma to increase market share , decrease costs, and grow profit margin has been adopted by some leading companies in the world. Six Sigma is expected as the optimal movement to raise the quality level remarkably and to make enterprise culture and organization based on customer and market orientation. In this paper, we study on the idea of Six Sigma, the Internal and external success case, the reliability tools using in the Six Sigma, and the difference between the existing quality movement and Six Sigma. Also, we discuss the role of reliability In Six Sigma..

• Journal of applied mathematics & informatics
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• v.39 no.3_4
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• pp.277-294
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• 2021

In this paper, we introduce the notions of Wijsman regularly invariant convergence types, Wijsman regularly (${\mathcal{I}}_{\sigma}$, ${\mathcal{I}}^{\sigma}_2$)-convergence, Wijsman regularly (${\mathcal{I}}^*_{\sigma}$, ${\mathcal{I}}^{{\sigma}*}_2$)-convergence, Wijsman regularly (${\mathcal{I}}_{\sigma}$, ${\mathcal{I}}^{\sigma}_2$) -Cauchy double sequence and Wijsman regularly (${\mathcal{I}}^*_{\sigma}$, ${\mathcal{I}}^{{\sigma}*}_2$)-Cauchy double sequence of sets. Also, we investigate the relationships among this new notions.

• Journal of Korean Society for Quality Management
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• v.45 no.1
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• pp.1-10
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• 2017

Purpose: Most enterprises adopt six sigma acts to maximize the business performance with raising the executiveness for the project improvements in each parts. But there are little studies about six sigma actual operations in manufacturing whether the six sigma improvements that have injected a lot of budget, efforts, labours and time are run properly. Methods: This study select 31 interviewees who have MBB or BB from 5 large enterprises running six sigma over 10 years and 5 SMEs running six sigma over 5 years to understand and review the operational status of six sigma actions in manufacturing industry and to secure representativeness. This study identify the operational status of six sigma actions and key factors enhancing or impeding execution of six sigma projects through face-to-face interviews and online surveys by e-mail. Results: This study figured out the operational status of six sigma actions and key factors enhancing or impeding execution of six sigma projects. We used SPSS 16.0 for the reliability and the validity of survey data. Conclusion: There can be a lot of different factors that affect six sigma project improvements besides the key factors from this study. More study need to think of the organization characteristics and the basic conditions and to remedy the unreasonable points and defects rather than following foreign companies and enterprises.

• Proceedings of the Safety Management and Science Conference
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• 2012.11a
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• pp.453-460
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• 2012

To maximize the operational efficiency of production and operations systems, Six Sigma and Lean Production System have been widely used. The main focus of Six Sigma is reducing variations, whereas that of Lean Production System is eliminating losses. To take advantage of the two approaches Six Sigma and Lean Production System was integrated into Lean Six Sigma, and the integrated approach has been used in recent years. In the implementation of Lean Six Sigma, the problems under consideration have often physical or technical contradictions which are difficult to be solved by conventional methods. To solve such contradictions TRIZ is useful in many cases. In this thesis, it is considered that how TRIZ can be applied to Lean Six Sigma. An integrated road-map of Lean Six Sigma and TRIZ is suggested and some cases are reviewed.

• Journal of the Chungcheong Mathematical Society
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• v.4 no.1
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• pp.103-113
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• 1991

Some properties of a path space and the fundamental group ${\sigma}(X,x_0,G)$ of a topological transformation group (X, G, ${\pi}$) are described. It is shown that ${\sigma}(X,x_0,H)$ is a normal subgroup of ${\sigma}(X,x_0,G)$ if H is a normal subgroup of G ; Let (X, G, ${\pi}$) be a transformation group with the open action property. If every identification map $p:{\Sigma}(X,x,G)\;{\longrightarrow}\;{\sigma}(X,x,G)$ is open for each $x{\in}X$, then ${\lambda}$ induces a homeomorphism between the fundamental groups ${\sigma}(X,x_0,G)$ and ${\sigma}(X,y_0,G)$ where ${\lambda}$ is a path from $x_0$ to $y_0$ in X ; The space ${\sigma}(X,x_0,G)$ is an H-space if the identification map $p:{\Sigma}(X,x_0,G)\;{\longrightarrow}\;{\sigma}(X,x_0,G)$ is open in a topological transformation group (X, G, ${\pi}$).

• Journal of Korean Institute of Industrial Engineers
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• v.32 no.4
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• pp.268-278
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• 2006

Ten years have passed since Samsung SDI and LG Electronics introduced six sigma. Six sigma spreads on the wide industry areas such as service and public sectors as well as manufacturing industry. Six sigma speaks for Korean enterprise's management innovation now. Then, can we evaluate that Korean enterprise's six sigma has settled down successfully? This study compares Korean enterprise's six sigma with those of Japanese and American enterprises in the view of leadership, project, people, and methodology. We suggest five topics for the successful settlement of six sigma in Korean enterprises; 1) Role of executives and managers should be changed more actively, 2) Strategy-connected projects should be excavated, 3) Utilization and development plan should be made for black belt and master black belt, 4) Six sigma methodology should be advanced, especially DFSS methodology, and finally 5) Several innovation methodology should be integrated.

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

• Korean Journal of Mathematics
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• v.18 no.2
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• pp.195-200
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• 2010

Let C be a closed convex set in ${\mathbb{S}}^m$ or ${\mathbb{H}}^m$. Assume that ${\Sigma}$ is an n-dimensional compact minimal submanifold outside C such that ${\Sigma}$ is orthogonal to ${\partial}C$ along ${\partial}{\Sigma}{\cap}{\partial}C$ and ${\partial}{\Sigma}$ lies on a geodesic sphere centered at a fixed point $p{\in}{\partial}{\Sigma}{\cap}{\partial}C$ and that r is the distance in ${\mathbb{S}}^m$ or ${\mathbb{H}}^m$ from p. We make use of a modified volume $M_p({\Sigma})$ of ${\Sigma}$ and obtain a sharp relative isoperimetric inequality $$\frac{1}{2}n^n{\omega}_nM_p({\Sigma})^{n-1}{\leq}Vol({\partial}{\Sigma}{\sim}{\partial}C)^n$$, where ${\omega}_n$ is the volume of a unit ball in ${\mathbb{R}}^n$ Equality holds if and only if ${\Sigma}$ is a totally geodesic half ball centered at p.

• Proceedings of the Korean Society for Quality Management Conference
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• 2004.04a
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• pp.155-159
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• 2004

Continuous quality improvement has generally been recognized as an essential requirement for a company to stay in business. For this reason, Six Sigma plays an important role In reducing cost and development time of a product and achieving high quality products in a competitive market. The Six Sigma has proven that it is possible to achieve dramatic performance improvement for conducting business. However, several recognized Six Sigma companies have suffered the financial troubles, even if the Six Sigma should be successfully deployed in their business organizations. In this paper, the reason of this paradox is represented and discussed for a successful Six Sigma deployment, including next generation of Six Sigma.