• 대한기계학회논문집A
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• 제30권8호
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• pp.985-992
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• 2006

Many methods for reliability analysis have been studied and one of them, a moment method, has the advantage that it doesn't require sensitivities of performance functions. The moment method for reliability analysis requires the first four moments of a performance function and then Pearson system is used for the probability of failure where the accuracy of the probability of failure greatly depends on that of the first four moments. But it is generally impossible to assess them analytically for multidimensional functions, and numerical integration is mainly used to estimate the moment. However, numerical integration requires many function evaluations and in case of involving finite element analyses, the calculation of the first fo 따 moments is very time-consuming. To solve the problem, this research proposes a new method of approximating the first four moments based on kriging metamodel. The proposed method substitutes the kriging metamodel for the performance function and can also evaluate the accuracy of the calculated moments adjusting the approximation range. Numerical examples show the proposed method can approximate the moments accurately with the less function evaluations and evaluate the accuracy of the calculated moments.

• 한국의류학회지
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• 제28권11호
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• pp.1516-1523
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• 2004

The purpose of this study were to analyze the effect of weft knit structural characteristics on the subjective texture and sensibility. For this, the material was knitted into 8 kinds of weft plain knit fabrics with four kinds of fiber components such as wool, acryl, rayon, and nylon, 3 steps of densities and 3 steps of twist numbers to ply two yarns. The data were analyzed by factor analysis, ANOVA and multidimensional scaling. From factor analysis, subjective textures were categorized as 'bulk/resilience', 'surface/density' and 'soft/drape', and subjective sensibilities were categorized as 'natural/comfortable', 'feminine/elegance' and 'stable/neat' Among the knit structural characteristics, the component of fibers and the density of fabrics were the important factors to give variations in texture and sensibility : In comparison with wool knit of medium density, the knit fabrics of other components and different densities each showed a unique texture and sensibility. But twist number to ply two yams had a few influence on subjective properties. As a result of MDS analysis, the texture and sensibility of plain weft knit fabrics was classified as 'thin-full', 'hard-soft', 'young-old' and 'warm-cool'.

• 경영정보학연구
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• 제11권1호
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• pp.181-196
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• 2009

최근 성능이 우수하고 가격이 저렴한 GPS수신기가 개발되면서 이동객체분석과 공간행태분석에 관한 관심이 높아지고 있다. 이러한 분석을 위한 정보기술과 방법에 관한 연구들이 다각적으로 이루어지고 있지만, 아직 실무에 적용하기에는 한계가 있다. 본 연구는 다차원 모델과 OLAP이라는 데이터분석 기법과 도구들을 이용하여 GPS를 활용한 공간행태분석 방법을 소개하고, 실제 사례를 통해 분석방법 및 분석결과를 제시하였다. 또한, GPS를 활용한 공간행태분석의 유용성과 한계점을 논하였다.

• 한국콘텐츠학회논문지
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• 제10권3호
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• pp.463-471
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• 2010

학습 본 연구의 목적은 블랜디드 러닝 환경에서 적용될 학업 성취 수준별 교수 학습 모형을 제안하는 것이다. 블랜디드 러닝 환경에 포함된 변인과 구조를 살펴보기 위해 웹 학습요소와 자기조절학습을 기초로 하여 두 종류의 설문지를 개발하였고, 또한 이를 적용한 반응을 근거로 하여 각 요소 간 위상과 경로를 표현하였다. 본 연구에서는 고등학생 154명을 실험 대상으로 2주간 사이버 학습을 실시하고 각 학습자의 성취 수준과 설문지 자료를 획득하였다. 또한 상관분석, 전통적 다차원척도법 그리고 중회귀분석을 적용하여 통계적 처리를 통해 각 요소 간 위상과 경로를 규명하고 블랜디드 러닝 모형을 정형화하였다.

• 대한간호학회지
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• 제50권2호
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• pp.228-241
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• 2020

Purpose: The purpose of this study was to develop an instrument to assess nursing professional pride. Methods: Fifty-six preliminary items were identified through literature review and focus group interview of nurses working in a hospital. Of these, 45 preliminary instruments were completed over 0.80 of content validity index. To verify the reliability and validity of the preliminary instrument, data were collected from 294 nurses. The data were analyzed using factor analysis and multidimensional scaling analysis. Results: From the factor analysis, 27 significant items were divided into 5 subscales. These subscales were as follows: feeling of vocation, role satisfaction, role of problem solver, self-achievement, and willingness to stay. The nursing professional pride also established criterion-related validity, discriminant validity, and group validity. Cronbach's α of the instrument was .92, and the subscales ranged from .74 to .85. Conclusion: The developed scale for nursing professional pride shows validity and reliability. The significance of this study is the development of an instrument capable of measuring nursing professional pride. To verify the relevance of this instrument, conducting comparative studies is suggested.

• 패션비즈니스
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• 제14권5호
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• pp.49-65
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• 2010

The purpose of this paper is to derive the categories of negative e-WOM (electronic word of mouth) via consumer review. Disclosing the details of negative e-WOM based consumer reviews has never been done before. For this reason, a content analysis was adopted to provide knowledge and understanding of the phenomenon. This paper analyzes the content of 630 consumer reviews posted on the open market internet site, www.auction.co.kr. The analysis was conducted from October 20th, 2008 to March 10th, 2009. The results indicated that the negative e-WOM based consumer reviews can be divided into two categories: the cognitive evaluation and the expression of consumer's emotion. The category of cognitive evaluation is consisted of negative e-WOM of product, negative e-WOM of service, and warning about the risk of purchasing products. The category of expressing consumers' emotion are composed of venting customers' dissatisfaction and passive response of dissatisfaction. Investigating the details of negative e-WOM has a number of implications. Most importantly, the results revealed multidimensional structure of negative e-WOM. This understanding of negative e-WOM communication allows marketers to improve products and services that better meet customers' current and future needs.

• 생태와환경
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• 제41권spc호
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• pp.1-10
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• 2008

We patterned water quality of agricultural reservoirs according to the differences of six physico-chemical environmental factors (TN, TP, DO, BOD, COD, and SS) using four different ordination methods: Principal Components Analysis (PCA), Detrended Correspondence Analysis (DCA), Nonmetric Multidimensional Scaling (NMS), and Isometric Feature Mapping (Isomap). The data set was obtained from the water quality monitoring networks operated by the Ministry of Agriculture and Forestry and the Ministry of Environments. Chlorophyll-${\alpha}$ displayed the highest correlation with COD, followed by TP, BOD, SS, and TN (p<0.01), while negatively correlated with altitude and bank height of the reservoirs (p<0.01). Although four different ordination methods similarly patterned the reservoirs according to the gradient of nutrient concentration, PCA and NMS appeared to be the most efficient methods to pattern water quality of reservoirs based on the explanation power. Considering variable scores in the ordination map, the concentration of nutrients was positively correlated with Chl-${\alpha}$, while negatively correlated with altitude and bank height. These ordination methods may help to pattern agricultural reservoirs according to their water quality characteristics.

• Nuclear Engineering and Technology
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• 제39권4호
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• pp.299-312
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• 2007

The program on thermal-hydraulic evaluation by testing and analysis (THETA) for the development and licensing of the new design features in the APR1400 (Advanced Power Reactor-1400) is briefly introduced with a presentation on the research motivation and typical results of the separate effect tests and analyses of the major design features. The first part deals with multi-dimensional phenomena related to the safety analysis of the APR1400. One research area is related to the multidimensional behavior of the safety injection (SI) water in a reactor pressure vessel downcomer that uses a direct vessel injection type of SI system. The other area is associated with the condensation of steam jets and the resultant thermal mixing in a water pool; these phenomena are relevant to the depressurization of a reactor coolant system (RCS). The second part describes our efforts to develop new components for safety enhancements, such as a fluidic device as a passive SI flow controller and a sparger to depressurize the RCS. This work contributes to an understanding of the new thermal-hydraulic phenomena that are relevant to advanced reactor system designs; it also improves the prediction capabilities of analysis tools for multi-dimensional flow behavior, especially in complicated geometries.

• 한국콘텐츠학회논문지
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• 제21권7호
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• pp.575-586
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• 2021

본 연구의 목적은 만성질환자의 건강행동에 대한 건강동기 개념의 속성을 파악하여, 만성질환자를 위한 근거기반 간호에 기여하고자 함이다. Walker와 Avant의 개념분석 단계에 따라 만성질환자의 건강과 관련된 동기에 대해 연구한 14편의 학술지 및 학위논문을 선정하고, 추가적 문헌고찰을 통해 개념을 분석하였다. 만성질환자의 건강동기 속성으로 다음의 3가지가 도출되었다. 첫째, 건강행동을 위한 심리적 욕구, 둘째, 개인적 특성을 고려한 다차원적인 상태, 셋째, 변화 가능하고 행동변화를 유발하는 정서적 힘이다. 본 연구에서 분석한 선행요인, 속성, 결과를 고려하여 건강동기를 증진하는 간호중재 프로그램 적용을 통해 근거에 기반한 체계적 만성질환자 관리를 할 수 있을 것으로 기대된다.

• 한국환경복원기술학회지
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• 제26권4호
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• pp.1-16
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• 2023

The purpose of this study is to understand the vegetation structure of the Corylopsis coreana habitats in South Korea and their correlation with environmental factors, in order to provide basic data for preparing conservation. A total of 40 vegetation survey plots were established in around Southern region, Gangwon-do and Gyeonggi-do Province. The cluster analysis revealed four distinct clusters: Quercus mongolica-Pinus densiflora (QmPd), Castanea crenata (Cc), Quercus mongolica (Qm), and Pinus koraiensis (Pk). Among them, the QmPd cluster was selected as the representative community. Soil texture analysis that most areas consisted of loamy soil and were distributed on the northern aspects. The plantation, represented by Pk, exhibited a high content of exchangeable aluminum (5.227±0.342 mg/kg), suggesting the need for soil improvement and monitoring in these habitats. The canopy openness (forest gap) ranged from 11% to 21%, indicating a relatively closed canopy in many survey plots. Non-metric multidimensional scaling analysis indicated heterogeneous species composition between the QmPd cluster and the Pk cluster (total R² = 0.608).