• Bulletin of the Korean Mathematical Society
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• 제52권6호
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• pp.1797-1803
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• 2015

Let ($S_{\alpha}(n))_{n{\geq}1}$ be the lexicographically greatest Sturmian word of slope ${\alpha}$ > 0. For a fixed ${\sigma}$ > 1, we consider Dirichlet series of the form ${\nu}_{\sigma}({\alpha})$ := ${\Sigma}_{n=1}^{\infty}s_{\alpha}(n)n^{-{\sigma}}$. This paper studies the singular properties of the real function ${\nu}_{\sigma}$, and the Lebesgue-Stieltjes measure whose distribution is given by ${\nu}_{\sigma}$.

• Journal of Microbiology
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• 제42권2호
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• pp.103-110
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• 2004

In order to understand the molecular basis of selective expression of stationary-phase genes by RNA polymerase containing$\sigma$$\^$38/ (E$\sigma$$\^$38/) in Escherichia coli, we examined transcription from the stationary-phase promoters, katEP, bo1AP, hdeABP, csgBAP, and mcbP, in vivo and in vitro. Although these pro-moters are preferentially recognized in vivo by E$\sigma$$\^$38/, they are transcribed in vitro by both E$\sigma$$\^$38/ and E$\sigma$$\^$70/ containing the major exponential $\sigma$, $\sigma$$\^$70/. In the presence of high concentrations of glutamate salts, how-ever, oldy E$\sigma$$\^$38/ was able to efficiently transcribe from these promoters, which supports the concept that the promoter selectivity of $\sigma$$\^$38/-containing RNA polymerase is observed only under specific reaction con-ditions. The examination of 6S RNA, which is encoded by the ssr1 gene in vivo, showed that it reduced E$\sigma$$\^$70/ activity during the stationary phase, but this reduction of activity did not result in the elevation of E$\sigma$$\^$38/ activity. Thus, the preferential expression of stationary-phase genes by E$\sigma$$\^$38/ is unlikely the con-sequence of selective inhibition of E$\sigma$$\^$70/ by 6S RNA.

• Bulletin of the Korean Mathematical Society
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• 제40권1호
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• pp.17-28
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• 2003

Let X be a closed, oriented, Riemannian 4-manifold with ${{b_2}^+}(x)\;>\;1$ and of simple type. Suppose that ${\sigma}\;:\;X\;{\rightarrow}\;X$ is an involution preserving orientation with an oriented, connected, compact 2-dimensional submanifold $\Sigma$ as a fixed point set with ${\Sigma\cdot\Sigma}\;{\geq}\;0\;and\;[\Sigma]\;{\neq}\;0\;{\in}\;H_2(X;\mathbb{Z})$. We show that if _X(\Sigma)\;+\;{\Sigma\cdots\Sigma}\;{\neq}\;0$ then the $Spin^{C}$ bundle $\={P}$ is not $\mathbb{Z}_2-equivariant$, where det $\={P}\;=\;L$ is a basic class with $c_1(L)[\Sigma]\;=\;0$.

• Korean Management Science Review
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• 제24권1호
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• pp.147-160
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• 2007

Six Sigma's concept has long been used as an effective way of restructuring the management process of a firm. In literature regarding Six Sigma, a number of successful cases were reported, where Six Sigma based management activities could enhance firm's strategic performance dramatically for year. However, there exist very few researches investigating the effect of Six Sigma on process innovation and quality improvement. Therefore this study propose a research model testing whether Six Sigma innovation could improve process innovation and quality improvement by industrial classification. We collected 332 valid questionnaires from expert in Six Sigma activities, and applied PLS. Empirical results showed that Six Sigma activities could contribute to process innovation and quality improvement.

• Korean Journal of Construction Engineering and Management
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• 제6권4호
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• pp.133-141
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• 2005

The object of this study is to present performance by applying six sigma quality management to a construction company. The research method involves to investigate and analyze data regarding six sigma projects in S construction company and a questionnaire survey from the personnel of the S construction company. The results of this study are as follows 1) S construction company utilized the six sigma quality management for 258 projects during the years of 2003 and 2004 and this bring the effect of cost reduction for quality. Moreover, before using the six sigma quality management, the average level of sigma in this company was around 2.8, after using this, the level increased to 3.6. Particularly, the construction management part, the level increased from 1.3 to 2.6.2) respondents recognize that quality management costs by applying six sigma is reduced. but there is only a little operational efficiency because it is In the early stage of applying six sigma quality management.

• Journal of Korean Society for Quality Management
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• 제34권4호
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• pp.22-32
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• 2006

In these days, most of Korean industries advocates and utilizes Six Sigma as an integrated innovation tool for all their business and manufacturing processes. Six Sigma is known to bring more financial and managerial achievements than other innovation methods and tools. However, such successes are not always guaranteed. To adopt and implement Six Sigma successfully, it is necessary to grasp and understand essential characteristics of Six Sigma and then identify suitable elements and complements in consideration of vision, strategies, capability, circumstance and environment of the company. Step by step implementation plan may be built based on those ingredients. This study is to find out key ingredients (KIs) of Six Sigma. Potential ingredients selected from previous studies of success factors and ingredients of Six Sigma and TQM, and criteria of quality awards like MBNQA, EFQM, Deming prize and Korean National Quality Awards (KNQA) are classified into 11 categories based on experts' opinion and affinity analysis: management leadership, belt system, training, six sigma system, compensation, organization, corporate culture, customer focused, project selection, management of project results, and managerial achievements. Irrelevant or ineffective potential ingredients are discarded using factor analysis for the questionnaires answered by champions, MBB's and BB's of 90 Korean companies that have more than 3 years experience of Six Sigma. Also from the factor analysis, 3 factors are derived for each categories respectively except the managerial achievement category. Those 11 categories and 30 factors are defined as KIs of Six Sigma. This study also reveals that there is difference according to enterprise size, type of business, and implementation time in terms of KI's, and prioritizes KI's that an enterprise to pursue Six Sigma successfully should consider according to its characteristics.

• Communications of the Korean Mathematical Society
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• 제28권3호
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• pp.425-432
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• 2013

Let S be a minimal surface of general type with $p_g(S)=q(S)=0$ having an involution ${\sigma}$ over the field of complex numbers. It is well known that if the bicanonical map ${\varphi}$ of S is composed with ${\sigma}$, then the minimal resolution W of the quotient $S/{\sigma}$ is rational or birational to an Enriques surface. In this paper we prove that the surface W of S with $K^2_S=5,6,7,8$ having an involution ${\sigma}$ with which the bicanonical map ${\varphi}$ of S is composed is rational. This result applies in part to surfaces S with $K^2_S=5$ for which ${\varphi}$ has degree 4 and is composed with an involution ${\sigma}$. Also we list the examples available in the literature for the given $K^2_S$ and the degree of ${\varphi}$.

• Journal of the Korean Mathematical Society
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• 제54권1호
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• pp.281-302
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• 2017

For a Banach space operator $A{\in}B(\mathcal{X})$, let ${\sigma}(A)$, ${\sigma}_a(A)$, ${\sigma}_w(A)$ and ${\sigma}_{aw}(A)$ denote, respectively, its spectrum, approximate point spectrum, Weyl spectrum and approximate Weyl spectrum. The operator A is polaroid (resp., left polaroid), if the points $iso{\sigma}(A)$ (resp., $iso{\sigma}_a(A)$) are poles (resp., left poles) of the resolvent of A. Perturbation by compact operators preserves neither SVEP, the single-valued extension property, nor the polaroid or left polaroid properties. Given an $A{\in}B(\mathcal{X})$, we prove that a sufficient condition for: (i) A+K to have SVEP on the complement of ${\sigma}_w(A)$ (resp., ${\sigma}_{aw}(A)$) for every compact operator $K{\in}B(\mathcal{X})$ is that ${\sigma}_w(A)$ (resp., ${\sigma}_{aw}(A)$) has no holes; (ii) A + K to be polaroid (resp., left polaroid) for every compact operator $K{\in}B(\mathcal{X})$ is that iso${\sigma}_w(A)$ = ∅ (resp., $iso{\sigma}_{aw}(A)$ = ∅). It is seen that these conditions are also necessary in the case in which the Banach space $\mathcal{X}$ is a Hilbert space.

• Communications of the Korean Mathematical Society
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• 제9권4호
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• pp.767-772
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• 1994

For an $n \times n$ complex matrix $A = [A_{ij}]$, the permanent of A, per A, is defined by $$ per A = \sub_{\sigma \in S_n}{a_{1 \sigma(1)} a_{2 \sigma(2)} \cdots a_{n \sigma(n)} $$ where $S_n$ stands for the symmetric group on the set {1, 2, ..., n}.

• Proceedings of the Korean DIstribution Association Conference
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• 한국유통학회 2000년도 추계학술대회 발표논문집
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• pp.187-205
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• 2000

6 Sigma movement is the quality innovation activity which Motorola, a nineteen eighties' top-ranking American company of electronics and communication, has started to survive the Japanese companies' frightening gami-gaze. In early days, it's just applicated for reducing customers' complain by eliminations inferior goods centering round producing activity and filling up the competitive market's demand for price and delivery deadline. Nowaday, 6 Sigma application has created a boom extending to a company's most activity fields without any exact scrutiny of 6 Sigma. Although 6 Sigma movement starts from the question of what customers want not by cutting off the inferiority rate but by cutting out causes of producing inferior goods, the service industry has a special character that makes it difficult to compute the level of Sigma. Thus this research examines suitability for introduction of 6 Sigma to the Service Industry.