• Wind and Structures
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• 제18권1호
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• pp.57-67
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• 2014

For a building with a dominant windward wall opening, the wind-induced internal pressure response can be described by a second-order non-linear differential equation. However, there are two ill-defined parameters in the governing equation: the inertial coefficient $C_I$ and the loss coefficient $C_L$. Lack of knowledge of these two parameters restricts the practical use of the governing equation. This study was primarily focused on finding an accurate reference value for $C_I$, and the paper presents a systematic investigation of the factors influencing the inertial coefficient for a wind-tunnel model building including: opening configuration and location, wind speed and direction, approaching flow turbulence, the model material, and the installation method. A numerical model was used to simulate the volume deformation under internal pressure, and to predict the bulk modulus of an experimental model. In considering the structural flexibility, an alternative approach was proposed to ensure accurate internal volume distortions, so that similarity of internal pressure responses between model-scale and full-scale building was maintained. The research showed 0.8 to be a reasonable standard value for the inertial coefficient.

• 대한안전경영과학회지
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• 제19권1호
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• pp.157-167
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• 2017

The two-way quality theory has been widely used as a method for classifying quality attributes for several decades. In particular, the Kano model that classifies attributes into not just conventional one-dimensional but must-be and attractive has gained popularity due to its applicability and ease of use. However, the wordings of the five alternatives in the Kano's questionnaire has been criticised for unclear meanings. This study proposes a new two-way model to classify attributes using 5-point Likert scale alternatives. For this, the current paper investigated a case of TV sets to examine how the proposed model works in comparison with the Kano model. The application results of the proposed model are different from the original one. The two-way model classifies quality attributes in more detail such as the "one-dimensional with an attractive tendency" attribute, which has a greater influence on satisfaction than dissatisfaction, the opposite "one-dimensional with a must-be tendency" attribute, and "highly one-dimensional" and "less one-dimensional" attributes. In this study, a potential satisfaction coefficient (PSC), a potential dissatisfaction coefficient (PDC), and an average potential coefficient (APC) to manage quality attributes are proposed and discussed for their utilization.

• 한국환경과학회지
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• 제11권9호
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• pp.829-842
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• 2002

The purpose of this study was to design a reliable and valid Likert-type scale to measure nuclear energy attitudes of various groups. 8 tests were applied to the construction of a 26-item long form, a 12-item middle form, and a 6-item short form of the scale. Three scales were field tested on 760 respondents representing a diverse range of subjects. The 26-item scale appeared to be reliable, content valid and construct valid. Scale reliability and homogeneity were evidenced by 0.95 coefficient alpha and positive interitem correlations ranging from 0.18 to 0.74. The results of factor analysis and known-groups comparison revealed that this scale had high validity. Reliability of the middle form and short form were evidenced by coefficient alpha of 0.92 and 0.90 respectively. The long and middle forms were strongly correlated, r-value of 0.98 and the long and short forms were also highly correlated, r-value of 0.93. Consequently, long form, middle form and short form scales were evidenced very reliable and valid in measuring nuclear energy attitudes of various groups in general. They can be used for a variety of purpose of measuring and testing nuclear energy attitude.

• International Journal of Naval Architecture and Ocean Engineering
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• 제6권4호
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• pp.965-980
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• 2014

This paper presents a new estimation method of full scale propulsive performance for the pulling type podded propeller. In order to estimate the drag of pod housing, a drag velocity ratio, which includes the effects of podded propeller loading and Reynolds number, is presented and evaluated through the comparison of model test and numerical analysis. By separating the thrust of propeller blade and the drag of pod housing, extrapolation method of pod housing drag to full scale is deduced, and correction method of propeller blade thrust and torque to full scale is presented. This study utilized the drag coefficient ratio of the pod housing as a measure for expanding it to full scale, but in order to increase the accuracy of performance evaluation, additional study is necessary on the method for the full scale expansion via separating the drag of pod body, strut and fin which consist the pod housing.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2014년도 제49회 KOSCO SYMPOSIUM 초록집
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• pp.15-16
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• 2014

With the increasing trend in CFB(Circulating Fluidized Bed) boiler scale, the EHE(External Heat Exchanger) must be adopted to the large-scale boilers to recover insufficient heat transfer surface. In this study, the numerical analysis model for EHE in commercial 300MWe CFB boiler was developed with the inclusion of mechanistic model, which enables the heat transfer prediction. Finally, the calculated absorbed heat and derived heat transfer coefficient are evaluated through the verification with experimental data.

• 정신신체의학
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• 제3권1호
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• pp.49-57
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• 1995

To evaluate body image disturbance in Korea, the Body Image Scale(BIS) was developed and it's reliability and validity was tested. The BIS was administered to 33 subjects of normal controls and 64 patients consisting of mainly neurotic patients. The correlation coefficient, of test-retest reliability with an interval of 2 weeks was 0.88 and internal consistency coefficient Cronbach's alpha, was 0.80. Discriminant validity test indicated that there were significant differences in total BIS score between normal control group and psychiatric patients group after controlling the effects of age, sex, and educational level. Factor analysis showed two distinct dimensions, namely 'physical appearance' and 'physical health and strength'. The BIS appears to be a reliable, internally consistent and valid scale which can be used for assessing body image in Korea pupulations.

• 기본간호학회지
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• 제8권1호
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• pp.95-104
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• 2001

This study was done to develop an euthanasia attitude scale. Subjects who participated in the study were a convenience sample of 234 Korean nurses. Data were collected through a survey over a period of three months. The analysis of the data was done using SPSS PC for descriptive statistics, factor analysis and Cronbach's Coefficient Alpha. Initially 63 items were generated from interview data from eighteen nurses and from a literature review. This preliminary scale was analyzed for a reliability and validity. The results are as follow: 1, Crombach's Coefficient alpha for the 19 items was .8804. 2. Factor analysis was done in order to confirm construct validity and four factor were extracted from the results. These contributed 56.6% of the variance in the total score. 3. Each factor was labled 'qualify of life', 'respect of life, 'client's right', 'medical ethics'. The author suggests that this scale could be used in assessing the attitude of Korean nurses toward euthanasia.

• Child Health Nursing Research
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• 제18권2호
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• pp.76-84
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• 2012

Purpose: This study was done to develop a cell phone addiction scale for Korean children. Methods: The process included construction of a conceptual framework, generation of initial items, verification of content validity, selection of secondary items, preliminary study, and extraction of final items. The participants were 268 children from grades 4 to 6 in two urban elementary schools. Construct validity, internal consistence reliability, and split-half reliability were used to analyze the data. Results: Nine items were categorized into 2 factors explaining 61.29% of total variance. The factors were labeled as obsessive compulsion (6 items) and dependency (3 items). Cronbach's alpha coefficient for the 9 items was .87, and Spearman-Brown coefficient was .83. Scale scores identified children as high risk users, at risk users, or average users by standard scores. Conclusion: The above findings indicate that the cell phone addiction scale for children has good validity and reliability when used with Korean children.

• 한국통신학회논문지
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• 제41권7호
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• pp.754-764
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• 2016

최근 들어 다양한 SNS(Social Network Service)에 대한 이해와 분석을 위해 가장 중요한 두 종류의 망인 small-world와 scale-free망에 대한 많은 연구가 수행되고 있다. 본 연구에서는 두 개의 입력 파라미터를 적절히 조정함으로서 small-world 망, scale-free 망 혹은 두 개의 성질을 동시에 모두 갖는 망을 생성 할 수 있는 보다 일반화된 망 생성 방법을 제안하였다. 두개의 입력 파라미터중 하나는 small-world 성질을 나태내주는 파라미터고 다른 하나는 scale-free와 small-world 성질 모두를 나타내주는 파라미터다. Small-world와 scale-free를 나타내주는 망의 성질로 군집계수, 평균 최단거리 그리고 power-law 상수를 이용하였다. 본 연구에서 제안한 방법을 사용하면 small-world 망과 scale-free 망의 성질과 관계에 대한 보다 명확한 이해를 할 수 있다. 다양한 여러 예제들을 통하여 두 개의 입력 파라미터들이 군집계수, 평균 최단거리 그리고 power-law 상수에 미치는 영향을 검증하였다. 이를 통해 어떠한 입력 파라미터들의 조합이 small-world 망, scale-free 망 혹은 두 개의 성질을 모두 갖는 망을 생성 할 수 있는지를 조사하였다.

• 성인간호학회지
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• 제13권3호
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• pp.486-495
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• 2001

The purpose of this study was to develop a Quality of Life(QOL) scale for breast cancer patients in Korea and to test the validity and reliability of the instrument. To achieve the purpose of the study, a questionnaire was developed to interview 10 breast cancer patients and distributed to 155 patients with breast cancer in Korea. For data analysis, SPSS WIN 8.0/PC were used. Item analysis and factor analysis were carried out to test validity of the QOL scale. Cronbach's ${\alpha}$ and Guttman split half coefficient were used to test reliability of the scale. The results were as follows; As a result of the item analysis, 27 items were selected from the total of 34 items. 6 factors were selected by factor analysis. Six factors were labeled as 'response to cancer diagnosis and treatment', 'family well-being', 'physical concerns', 'psychological well-being', 'spiritual well-being', and 'economic concerns'. Six factors were explained by 72.236% out of the total variance. The first factor explained 20.738% and the second factor explained 16.593%, which were major factors for Korean breast cancer patients. Chronbach's ${\alpha}$ coefficient of the tool was .9120, and Guttman split-half coefficient was .8148. The scale was identified to be a tool with a high degree of reliability and validity. Therefore, this scale can be effectively utilized for assessment of Quality of Life of patients with breast cancer in Korea.