• Nuclear Engineering and Technology
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• v.53 no.3
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• pp.715-731
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• 2021

Uncertainties are calculated for pressurized water reactor (PWR) spent nuclear fuel (SNF) characteristics. The deterministic code STREAM is currently being used as an SNF analysis tool to obtain isotopic inventory, radioactivity, decay heat, neutron and gamma source strengths. The SNF analysis capability of STREAM was recently validated. However, the uncertainty analysis is yet to be conducted. To estimate the uncertainty due to nuclear data, STREAM is used to perturb nuclear cross section (XS) and resonance integral (RI) libraries produced by NJOY99. The perturbation of XS and RI involves the stochastic sampling of ENDF/B-VII.1 covariance data. To estimate the uncertainty due to modeling parameters (fuel design and irradiation history), surrogate models are built based on polynomial chaos expansion (PCE) and variance-based sensitivity indices (i.e., Sobol' indices) are employed to perform global sensitivity analysis (GSA). The calculation results indicate that uncertainty of SNF due to modeling parameters are also very important and as a result can contribute significantly to the difference of uncertainties due to nuclear data and modeling parameters. In addition, the surrogate model offers a computationally efficient approach with significantly reduced computation time, to accurately evaluate uncertainties of SNF integral characteristics.

• Structural Engineering and Mechanics
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• v.68 no.5
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• pp.549-561
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• 2018

Sobol method is applied as a powerful variance decomposition technique in the field of global sensitivity analysis (GSA). The paper is devoted to increase convergence speed of the extracted Sobol indices using a new proposed sampling technique called genetic based Latine hypercube sampling (GBLHS). This technique is indeed an improved version of restricted Latine hypercube sampling (LHS) and the optimization algorithm is inspired from genetic algorithm in a new approach. The new approach is based on the optimization of minimax value of LHS arrays using manipulation of array indices as chromosomes in genetic algorithm. The improved Sobol method is implemented to perform factor prioritization and fixing of an uncertain comprehensive high speed rotor-bearing system. The finite element method is employed for rotor-bearing modeling by considering Eshleman-Eubanks assumption and interaction of axial force on the rotor whirling behavior. The performance of the GBLHS technique are compared with the Monte Carlo Simulation (MCS), LHS and Optimized LHS (Minimax. criteria). Comparison of the GBLHS with other techniques demonstrates its capability for increasing convergence speed of the sensitivity indices and improving computational time of the GSA.

• Journal of the Korean Society of Clothing and Textiles
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• v.17 no.2
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• pp.281-289
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• 1993

Concept of the comfort and fitness becomes a major concern in the basic function of the ready-made clothes. Accordingly a more sophiscated classification of the human morphological characteristics is strongly required for the effective clothing construction. This research was performed to classify and characterize Korean adult males anthropometrically. Sample size was 1290 subjects and their age range was from 19 to 54 years old. Sampling was carried out by the stratified sampling method. Data were collected by the direct anthropometric measurement. 75 variables in total were applied to classify the bodytypes. Data were analyzed by the multivariate method, especially factor and cluster analysis. The high factor loading items extracted by factor analysis were based to determine the variables of the cluster analysis for the similar bodytypes respectively. In the part of the trunk, 19 variables from the data were applied to classify the bodytypes of trunk by Ward's minimum variance method. The groups forming a cluster were subdivided into 5 sets by cross-tabulation extracted by the hierarchical culster analysis. Type 3 and 4 in trunk were composed of the majority of 55.6% of the subjects. The Korean adult males had relatively well-balanced bodytypes in trunk.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.12 no.4
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• pp.87-92
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• 2013

In this study, we carried out the turning of plastic mold steel(STAVAX) with whisker reinforced ceramic tool(WA1) and analyzed ANOVA(Analysis of Variance) test. Multi-regression analysis was performed to find influential factors to surface roughness and to derive regression equation. Results are follows: From ANOVA test and confidence interval analysis of surface roughness, We found that influential factors to surface roughness was feed rate, cutting speed and depth of cut in order. From multi-regression analysis, we derived regression equation of STAVAX. it's coefficient of determination($R^2$) was 0.945 and It means that regression equation is significant. From experimental verification, we confirmed that surface roughness was predictable by regression equation. Compared with former research, we confirmed that increase of feed rate is the main cause of the growing of surface roughness and cutting force.

• Journal of Korean Academy of Nursing
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• v.45 no.5
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• pp.650-660
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• 2015

Purpose: The purpose of this study was to develop an instrument to measure the parenting behavior of primary caregivers of children in early childhood. Methods: An instrument was developed according to Devellis's instrument development process. The participants in this study who completed the main survey were 370 mothers and grandmothers. The survey was conducted from June 1 to July 30, 2014, and collected data were analyzed using item analysis, half-split reliability and Cronbach's ${\alpha}$ coefficient, exploratory and confirmatory factor analysis, convergent validity. Results: The factor structure of the instrument showed the cumulative variance as 55.7% in the factor analysis. As a result of a confirmatory factor analysis, a four-factor structure was found to be appropriate, and the construct validity and convergent validity of the instrument were thereby confirmed. The finalized parenting behavior instrument consisted of 26 items and four independent factors: affectionate, laissez-faire, educational and impulsive. A five-point Likert scale was employed, and a higher score in a particular factor showed that most of the behaviors belonged to the factor. Conclusion: The instrument developed in this study was found to be reliable and valid, and can be used to develop parent-child relationship building.

• Journal of the Korean housing association
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• v.26 no.1
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• pp.11-18
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• 2015

The purpose of this research is to analyze the relationships between spatial characteristics and social functions of elderly center in apartment complex. The data for the analysis were collected from July 3 to 13, 2012 in Ulsan by interviewing 177 elderly persons from 56 elderly centers in apartment complex, and were analyzed with descriptive statistics, analysis of variance, and multiple regression analysis. The eleven questions for social functions of elderly center were developed by the researchers based on the related literatures and were categorized into four factors including kinship, social interaction, leisure activity, and community belonging. The social functions of elderly center were found to be evaluated moderately appropriate except for the community belonging. The results of the multiple regression analysis of total social functions of elderly center provide strong support for the model. Five variables (one-person household, health condition, location of the center, floor plan of the center, and user organization) are shown to be significantly related to total social functions of the elderly center.

• Steel and Composite Structures
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• v.23 no.1
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• pp.31-40
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• 2017

This article aims at presenting multi objective optimization of parameters that affect crashworthiness characteristics of bi-tubular structures using Taguchi method with grey relational analysis. To design the experiments, the $L_9$ orthogonal array has been used and based on that, the inner tubes have been fabricated by varying the three influence factors such as reference diameter, length difference and numbers of sides of the polygon with three levels, but all the outer cylinders have the same diameter and length 90 mm and 135 mm respectively. Then, the tailor made bi-tubular steel structures were subjected into quasi static axial compression. From the test results it is found that the crushing behaviors of bi-tubular structures with different combinations were fairly significant. The important responses (crashworthiness indicators) specific energy absorption and crush force efficiency have been evaluated from load - displacement curve. Finally optimal levels of parameters were identified using grey relational analysis, and significance of parameters was determined by analysis of variance. The optimum crashworthiness parameters are reference diameter 80 mm, length difference 0 mm and number of sides of polygon is 3, i.e., triangle within the selected nine bi-tube combinations.

• Food Quality and Culture
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• v.2 no.1
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• pp.27-31
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• 2008

The objective of this study was to develop sensory lexicons that can be utilized for various types of tofu such as pressed, unpressed, and tofu made from germinated soybeans, using generic descriptive analysis. In the first phase of the experiment, trained descriptive panelists developed and defined the appearance, aroma, flavor, and texture attributes that are commonly present in tofu. Then, the sensory characteristics of seven types of tofu were analyzed using the sensory lexicons established in the initial stage of the experiment. Four appearance, 6 odor/aroma, 6 flavor/taste, 7 texture, and 4 aftertaste attributes were identified, and reference standards were established for most of the terms in order to facilitate the understanding of the attribute definitions. The intensities of the sensory attributes were measured on a 15-point scale. Statistical analyses, including analysis of variance and principal component analysis, were used for the data. The seven tofu samples showed significant differences in the intensities of 22 attributes. The unpressed tofu samples were generally rated as being high in moistness, easy to cut, silky, and easy to swallow. The pressed tofu, on the other hand, was salty, astringent, beany, hard, and rough in texture. The tofu made with germinated soybeans was characterized as having a strong cooked bean flavor, salty and astringent aftertaste, and hard texture. Overall, the attributes of moistness, easy to swallow, and silkiness showed strong positive correlations; hardness and sticks to teeth were also positively correlated to each other.

• Journal of Technologic Dentistry
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• v.32 no.2
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• pp.77-90
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• 2010

Purpose : The purpose of study was to survey self-efficacy and job satisfaction for 500 dental technicians. Methods : The subjects were composed of 500 dental technicians in Daegu Metropolitan city and Gyeong-buk. This study was done using the Statistical Package for Social Sciences 17.0 for Windows. As for the analysis methods, the study used the frequency analysis, percentage, mean, t-test, analysis of variance, multiple regression analysis. Results : Self-efficacy of dental technician shows self confidence(M= 3.56), self regulatory efficacy(M=3.48), task difficulty preference(M=3.46). Job satisfaction of dental technician shows affairs satisfaction(M=3.58), colleague satisfaction(M=3.57), promotion satisfaction(M=3.48), salary satisfaction(M=3.56). Self-efficacy which affect on job satisfation was self confidence and self regulatory efficacy. Conclusion : A sense of self-efficacy and degree of job satisfaction are high when the sense of the degree of job satisfaction could be high only through a high sense of self-efficacy. In order to promote dental technician and dental hygienist of self-efficacy and job satisfaction, education and career and monthly salary is required high.

• Journal of Korean Academy of Nursing
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• v.47 no.5
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• pp.589-599
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• 2017

Purpose: The purpose of this study was to develop a scale to assess the transition shock experienced by newly graduated nurses, and test the validity and reliability of the scale. Methods: The initial items were identified through a review of literature and in-depth interviews with nine newly graduated nurses. Content validation of the items was evaluated by five nurse professors and three nurses. Participants were 269 newly graduated nurses who worked at six acute care hospitals in Busan, Ulsan, and Yangsan, South Korea. Data were analyzed using item analysis, exploratory and confirmatory factor analysis, criterion related validity, and internal consistency. Results: The final scale consisted of 18 items and six factors (conflict between theory and practice, overwhelming workload, loss of social support, shrinking relationship with co-workers, confusion in professional nursing values, and incongruity in work and personal life), which explained 71.3% of the total variance. The six subscale model was validated by confirmatory factor analysis. Cronbach's alpha for the total items was. 89. Convergent validity was evaluated by analyzing total correlation with burnout (r=.71, p<.001) and turnover intention (t=5.84, p<.001). Conclusion: This scale can be used in the development of nursing interventions to reduce the transition shock experienced by newly graduated nurses.