• Steel and Composite Structures
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• v.20 no.3
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• pp.623-649
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• 2016

Most of the early studies on plates vibration are focused on two-dimensional theories, these theories reduce the dimensions of problems from three to two by introducing some assumptions in mathematical modeling leading to simpler expressions and derivation of solutions. However, these simplifications inherently bring errors and therefore may lead to unreliable results for relatively thick plates. The main objective of this research paper is to present 3-D elasticity solution for free vibration analysis of continuously graded carbon nanotube-reinforced (CGCNTR) rectangular plates resting on two-parameter elastic foundations. The volume fractions of oriented, straight single-walled carbon nanotubes (SWCNTs) are assumed to be graded in the thickness direction. In this study, an equivalent continuum model based on the Eshelby-Mori-Tanaka approach is employed to estimate the effective constitutive law of the elastic isotropic medium (matrix) with oriented, straight carbon nanotubes (CNTs). The proposed rectangular plates have two opposite edges simply supported, while all possible combinations of free, simply supported and clamped boundary conditions are applied to the other two edges. The formulations are based on the three-dimensional elasticity theory. A semi-analytical approach composed of differential quadrature method (DQM) and series solution is adopted to solve the equations of motion. The fast rate of convergence of the method is demonstrated and comparison studies are carried out to establish its very high accuracy and versatility. The 2-D differential quadrature method as an efficient and accurate numerical tool is used to discretize the governing equations and to implement the boundary conditions. The convergence of the method is demonstrated and to validate the results, comparisons are made between the present results and results reported by well-known references for special cases treated before, have confirmed accuracy and efficiency of the present approach. The novelty of the present work is to exploit Eshelby-Mori-Tanaka approach in order to reveal the impacts of the volume fractions of oriented CNTs, different CNTs distributions, various coefficients of foundation and different combinations of free, simply supported and clamped boundary conditions on the vibrational characteristics of CGCNTR rectangular plates. The new results can be used as benchmark solutions for future researches.

• International Commerce and Information Review
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• v.19 no.1
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• pp.213-234
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• 2017

This study analyzed valid samples of 707 units collected by conducting paper and online surveys on the Korean, the Chinese, the American, and the Japanese. The result showed that a significant causal relationship exists between power distance and pull motivation as well as collectivism and push motivation, which led to a conclusion that developing travel packages that can strengthen bonding of fraternal societies through various events and attractions is effective for respondents from Asian countries. On the other hand, Americans turned out to prefer practical plans, which could provide individual's needs and preferences, for example, a self-healing package. This study, using a simple survey, may have a limitation in that it does not allow the participants to express their opinions. However, the study is meaningful that it made a theoretical contribution utilizing Hofstede's cultural dimensions index, two types of motivation, and theories of customer satisfaction and revisit intention. It also has a practical implication in that it proposes the most optimal and applicable overseas travel marketing strategy by comparing cultural traits of each country.

• Journal of Korean Academy of Nursing
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• v.25 no.1
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• pp.141-155
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• 1995

The objective of this study was to develop a scale to measure stress in infertile couples and to test its reliability and validity. Prior to item generation, a basic decision was made to conceptualize stress in infertile couples as including two dimensions and four subdimensions. The dimensions were, intrapersonal stress including cognitive and affective stress, and interpersonal stress including marital and social stress. Initially 95 items were generated from the inter-view data of 31 primary or secondary infertile women and from a literature review. These items were analyzed through the Index of Content Validity(CVI) and 69 items were selected which met 70% or more of the CVI. This preliminary Infertility Stress Scale were analyzed for reliability and construct validity. Item analysis and factor analysis were applied for construct validity. Forty items were selected through item analysis. This procedure was based on the inter-item correlation matrix, a corrected average inter-item correlation coefficient(.30~.70), a corrected item to total correlation coefficient (.03 or more) and information about the alpha estimate if this item was dropped from the scale. The result of the initial factor analysis including varimax rotation produced eight factors. Five items deleted because of factor complexity(indiscriminate factor loadings). The secondary factor analysis including varimax rotation produced seven factors that coincided with the conceptual framework posed for the scale developed. The seven factors were labeled as ‘meaning of children’,‘worthiness’,‘tenacious linking’,‘marital satisfaction’,‘sexual satisfaction’,‘familial adjustment’ and ‘social adjustment’. The alpha coefficient relating to internal consistency was .93 for reliability The results of this study suggest that the measurement derived from the Infertility Stress Scale is useful in assessing the stress of infertile couples.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.10 s.113
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• pp.993-999
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• 2006

This paper presents the design simulation, implementation, and measurement of a miniaturized DCS, PCS / Satellite DMB dual-band stacked chip antenna with double coupled line for mobile communication terminals. A stacked meander is realized by using a via hole with height of 0.8 mm and a diameter of 0.35 mm to connect upper- and lower-layer meander sections for a reduction of the dimensions of the antenna. In addition the stacked meander chip antenna is extended by a double coupled-line to achieve two different radiation modes. A ratio of the first frequency and second frequency vary with the geometrical parameter of coupled lines. The fabricated antenna used FR-4 substrate with relative permittivity of 4.2. And its dimensions are $15.2{\times}7{\times}0.8mm^3$. The measured impedance bandwidth(VSRW<2) are 244 and 120 MHz at the operating frequency, respectively.

• Culinary science and hospitality research
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• v.18 no.2
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• pp.82-90
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• 2012

This study was conducted to evaluate a take-out food safety perception instrument that could be used by foodservice establishments. A total of 324 responses was collected via online survey, and 299 responses (92.3%) were used for the statistical analysis. Data was randomly split into two groups. Exploratory Factor Analysis (EFA) was performed on the first split-half sample (n=150) to identify a factor structure using standard principal component analysis. EFA revealed three dimensions, titled "Consumer food safety perception," "Take-out food handling," and "Elements impacting on purchase decisions." Confirmatory Factor Analysis (CFA) was performed on the remaining half sample (n=149) using Structural Equation Modeling (SEM). CFA revealed acceptable absolute model fits for three dimensions and excellent comparative model fits for the instrument. These findings propose standardized measures that can be useful in assessing the take-out food safety perception.

• Culinary science and hospitality research
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• v.20 no.1
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• pp.1-17
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• 2014

Under the needs to study the predictors of the frontline employees' service-oriented organizational citizenship behaviors(OCBs) in the hotel industry, this study aimed to the influence of goal orientations on the OCBs. The two factors of performance goal and learning goal orientations were hypothesized to influence each dimension of OCBs(loyalty, service delivery, and participation). The data from 266 five star deluxe hotel employees were analyzed with descriptive statistics, multi-variate analysis of variance, and structural equation modeling conducted using SPSS 19.0 and AMOS 20.0. The results showed learning goal orientation positively influenced all dimensions of the OCBs while performance goal orientation positively influenced all dimensions except loyalty. These results suggest that hotel practitioners need to seek the applicants who are willingly oriented to specific goals at recruiting process. Furthermore, hotel organizations need to utilize the employees' goal approach to motivate their performances.

• Journal of Science Education
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• v.36 no.2
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• pp.341-353
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• 2012

The purpose of this study is to explore how science teachers' views about physics and biology are different. From a survey of 45 science teachers who majored in physics, this study found that their views about physics were closer to the experts' views than their views about biology. But it seemed that their views about neither physics nor biology were similar to the experts' views. Compared their views about physics with their views about biology in six dimensions, in four dimensions including structure dimension, methodology dimension, validity dimension, and reflective thinking dimension, the scores of the views about physics were higher, in learnability dimension, the scores of the views about biology were higher, and in personal relevance dimension, the scores of the two kinds of views were similar. Specially the their views about physics in learnability dimension were closer to novices'. In addition, science teachers majored in physics seemed to think that compared with biology, physics is coherent, systematic and reasoning, but it is not learnable.

• Journal of the Korean Society of Clothing and Textiles
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• v.30 no.9_10 s.157
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• pp.1378-1388
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• 2006

We conducted a questionnaire survey of 481 Korean female college students and measured anthropometrically 2 girth of their bodies(bust, under bust girth) in order to understand the psychological needs about brassiere and the physical characteristics of consumers aged between 19 and 25(the 1924 generation). There were two major problems to be solved to improve the fit of brassiere in aspect of size. First, most brands for this age group aimed at product differentiation mainly on visual design not on brassiere size. According to the body measurements, the distribution of brassiere size had 6 sections '70AA, 70A, 70B, 75AA, 75A and 75B cups' showing a rate of 63.8% but most brands for this age group were producing '75A, 80A, 85A, 75B, 80B and 85B cups' showing a rate of 24.7%. Second, most subjects of this survey didn't know their own breast size and the sizing system of brassiere which are necessary in order to select the proper brassiere size. And most subjects were wearing a bigger size brassiere than their own body size even though one was in the range of '75A, 80A, 85A, 75B, 80B and 85B'. It might be possible that the dimensions of brassiere products in the market and the sizes indicated on the labels do not correspond. For increasing the consumer satisfaction it is necessary to adjust the production rate of brassiere sizes and to develop ergonomic brassiere products with proper dimensions and shapes for each brassiere size.

• Science of Emotion and Sensibility
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• v.13 no.3
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• pp.523-532
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• 2010

In the field of user interface design for interactive product, it is becoming more important than ever to understand emotional quality and its characteristics. By a series of experiments on emotional quality of user interface, this paper aimed to develope a systematic approach to investigating emotional quality. First, a emotional quality framework that consists of 6 dimensions (Usefulness, Easy of Use, Aesthetics, Stimulation, Identification, and Harmony) and 18 elements was developed through two experiments that users and UI expert participated in. Second, by conducting a user survey based on the emotional quality framework, it was illustrated how various emotional qualities of interactive product can be evaluated and what effects they have on overall satisfaction of the product. Finally, this paper analyzed the relative importance of emotional quality dimensions and the contextual factors that change emotional quality, and provided basic knowledge related to the construction of emotional quality for the succeeding studies.

• The KIPS Transactions:PartD
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• v.8D no.2
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• pp.145-153
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• 2001

The Pyramid-Technique is based on mapping n-dimensional space data into one-dimensional data and expressing it as B-tree ; and by solving the problem of search time complexity the pyramid technique also prevents the effect \"phenomenon of dimensional curse\" which is caused by treatment of hypercube range query in n-dimensional data space. The Spherical Pyramid-Technique applies the pyramid method’s space division strategy, uses spherical range query and improves the search performance to make it suitable for similarity search. However, depending on the size of data and change in dimensions, the two above technique demonstrate significantly inferior search performance for data sizes greater than one million and dimensions greater than sixteen. In this paper, we propose a new index-structured PdR-Tree to improve the search performance for high dimensional data such as multimedia data. Test results using simulation data as well as real data demonstrate that PdR-Tree surpasses both the Pyramid-Technique and Spherical Pyramid-Technique in terms of search performance.