• Communications for Statistical Applications and Methods
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• 제10권2호
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• pp.507-517
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• 2003

Self-organizing map (SOM) has been developed mainly by T. Kohonen and his colleagues as a unsupervised learning neural network. Because of its topological ordering property, SOM is known to be very useful in pattern recognition and text information retrieval areas. Recently, data miners use Kohonen´s mapping method frequently in exploratory analyses of large data sets. One problem facing SOM builder is that there exists no sensible criterion for evaluating goodness-of-fit of the map at hand. In this short communication, we propose valid evaluation procedures for the Kohonen SOM of any size. The methods can be used in selecting the best map among several candidates.

• 한국IT서비스학회지
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• 제17권4호
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• pp.1-19
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• 2018

Effective internal communication is known to have a positive impact on business performance, but there is a lack of research on the effects of online channels for workplace communication. This study using regression analysis examines how task-technology fit, information richness, self-efficacy, perceived ease of use, and perceived usefulness related to online communication channels affect not only the satisfaction with the tools but also the effectiveness of them. Additionally, we verify how the organizational culture of online and offline communication shows the control effect. As a result, all five variables were positively correlated with internal communication channels satisfaction, and we found that the organizational culture of online and offline communication controls the relationship between online communication channels satisfaction and effectiveness.

• Journal of the Korean Statistical Society
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• 제26권2호
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• pp.199-210
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• 1997

Using regression methods based on quasi-likelihood equation, one only needs to specify the conditional mean and variance functions for the response variable in the analysis. In this paper, an omnibus lack-of-fit test is proposed to test the validity of these two functions. Our test is consistent against the alternative under which either the mean or the variance is not the one specified in the null hypothesis. The large-sample null distribution of our test statistics can be approximated through simulations. Extensive numerical studies are performed to demonstrate that the new test preserves the prescribed type I error probability. Power comparisons are conducted to show the advantage of the new proposal.

• 응용통계연구
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• 제25권4호
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• pp.651-659
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• 2012

In this paper we developed a statistical model for circular data with noises. In this case, model fitting by single circular model has a lack-of-fit problem. To overcome this problem, we consider some mixture models that include circular uniform distribution and apply an EM algorithm to estimate the parameters. Both von Mises and Wrapped skew normal distributions are considered in this paper. Simulation studies are executed to assess the suggested EM algorithms. Finally, we applied the suggested method to fit 2008 EHFRS(Epidemic Hemorrhagic Fever with Renal Syndrome) data provided by the KCDC(Korea Centers for Disease Control and Prevention).

• Structural Engineering and Mechanics
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• 제25권3호
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• pp.331-345
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• 2007

Uncertainties enter a complex analysis from a variety of sources: variability, lack of data, human errors, model simplification and lack of understanding of the underlying physics. However, for many important engineering applications insufficient data are available to justify the choice of a particular probability density function (PDF). Sometimes the only data available are in the form of interval estimates which represent, often conflicting, expert opinion. In this paper we demonstrate that Bayesian estimation techniques can successfully be used in applications where only vague interval measurements are available. The proposed approach is intended to fit within a probabilistic framework, which is established and widely accepted. To circumvent the problem of selecting a specific PDF when only little or vague data are available, a hierarchical model of a continuous family of PDF's is used. The classical Bayesian estimation methods are expanded to make use of imprecise interval data. Each of the expert opinions (interval data) are interpreted as random interval samples of a parent PDF. Consequently, a partial conflict between experts is automatically accounted for through the likelihood function.

• 한국생활과학회지
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• 제22권5호
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• pp.477-490
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• 2013

This study explores critical and success factor of benefits and risks for predicting the acceptance of QR code virtual fashion stores. As an exploratory approach, this study conducted focus group interviews(FGI) with 21 panels who had experience with selected QR virtual stores (e.g., Home plus, 11th Street, Pin & Fit). Content analysis was used to generate 184 excerpts and classify into benefits and risks related to QR code virtual stores. With respect to benefits, content analysis identified four factors: Affective appeal, perceived usefulness, ubiquity, and brand promotion. Also, contents regarding perceived risks were classified into four factors: Complexity, lack of information, lack of technology infrastructure, and perceived cost. A managerial implication was discussed for predicting consumer technology acceptance of a QR code virtual store in the fashion retailing market.

• 디지털융복합연구
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• 제18권12호
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• pp.117-125
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• 2020

본 논문에서는 지방자치단체에 근무하는 사회복지전담공무원의 조직적합성과 직무적합성이 직무열의에 미치는 영향을 살펴보되, 조직몰입의 매개효과를 함께 살펴보고자 하였다. 사회복지전담공무원의 경우에는 격무로 인한 스트레스와 심적 좌절감 등이 문제가 되고 있어 이들의 직무열의에 영향을 주는 요인을 확인하고자 한 것으로, 경기북부지역의 P시와 U시의 사회복지직 공무원 172명을 대상으로 설문조사를 실시하였고 중다귀회귀분석 방법을 활용하여 분석하였다. 연구결과 사회복지전담공무원의 직무열의에는 개인-직무적합성이 긍정적인 영향을 미치고 있는 것으로 나타났으며 조직몰입의 매개효과도 부분매개를 하는 것으로 조사되었다. 그러나 개인-조직적합성은 직무열의에 직접적인 영향은 나타나지 않으나 조직몰입을 통한 완전매개효과는 있는 것으로 나타났다. 이러한 연구결과 사회복지전담공무원들은 개인 차원의 능력이나 목적, 요구 등이 직무와 부합하고 있고 직무열의를 보이고 있는 반면, 조직 차원의 조직적합성에서는 조직 가치나 구조 등에 있어서 일치정도가 나타나지 않아 조직 내에서의 일치성과 친화력이 부족한 것으로 평가된다. 따라서 사회복지전담공무원의 직무열의를 제고하기 위해서는 조직 차원에서의 지원과 일체감 조성이 필요할 것으로 보인다.

• Journal of the Korean Data and Information Science Society
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• 제18권2호
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• pp.515-524
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• 2007

This paper deals with local linear estimation of fuzzy regression models based on Diamond(1998) as a new class of non-linear fuzzy regression. The purpose of this paper is to introduce a use of smoothing in testing for lack of fit of parametric fuzzy regression models.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2009년도 춘계학술대회
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• pp.423-427
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• 2009

This study proposes the generation mechanism of various design matrix using generalized linear model for design of experiment. Design generation method of GLM analysis, factorial design(FD) with center points, ANOVA design with lack-of-fit test, and response surface design are introduced. In central composite(CC) design, orthogonal blocking and fractional factorial design(FFD) are presented. We compare the design of Box-Benhken(BB) and face-centred central compsite design.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회/대한산업공학회 2003년도 춘계공동학술대회
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• pp.958-965
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• 2003

The rapidly changing business environment has required cooperation and coorduiation among functional units n organizations which should Involve group decision-making processes Although many group derision-making support tools and methods have provided the collaborative capabilities for organizational members, they often lack features supporting the dynamic complexity issue frequently occurring at group decision-making processes This study proposes system dynamics modeling as a group decision-making support tool to deal with the group derision-making tasks having properties of dynamic complexity in terms of cognitive fit theory.