• Journal of Electrical Engineering and Technology
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• v.10 no.5
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• pp.1958-1968
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• 2015

In this paper, a new definition of short-circuit ratio concept for multi-converter HVDC systems is proposed. Analysis results of voltage interaction between converters show that the reactive power-voltage characteristic of a converter has a dominant effect on voltage interaction level compared with its active power-voltage characteristic. Such a relation between converter reactive power and voltage interaction level supports taking the former into account in the definition of short-circuit ratio concept for multi-converter systems. The proposed definition is verified by the method of maximum power curve for various system configurations. Furthermore, a formula to calculate transient overvoltage for multi-converter systems is derived based on the proposed definition, and the efficiency of the derived formula is verified.

• Journal of Computational Design and Engineering
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• v.1 no.4
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• pp.289-297
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• 2014

Although big-sized markers are good for accurate marker recognition and tracking, they are easily occluded by other objects and deteriorate natural visualization and level of immersion during user interaction in AR environments. In this paper, we propose an approach to exploiting the use of rectangular markers to support tangible AR interaction based on fingertip touch using small-sized markers. It basically adjusts the length, width, and interior area of rectangular markers to make them more suitably fit to longish objects like fingers. It also utilizes convex polygons to resolve the partial occlusion of a marker and properly enlarges the pattern area of a marker while adjusting its size without deteriorating the quality of marker detection. We obtained encouraging results from users that the approach can provide better natural visualization and higher level of immersion, and be accurate and tangible enough to support a pseudo feeling of touching virtual products with human hands or fingertips during design evaluation of digital handheld products.

• Journal of the Korean Data and Information Science Society
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• v.19 no.4
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• pp.1059-1071
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• 2008

In a balanced factorial design with a nested factor where crossed factors as well as a nested factor exist simultaneously, powers of the rank transformed FR statistic for testing the main, nested and interaction effects are superior to those of the parametric F statistic. In heavy tailed distributions such as exponential and double exponential distributions, powers of the FR statistic show much higher level than those of the F statistic. Further powers of the F and FR statistic for testing the main effect show the highest level in an absolute size as compared with powers of the F and FR statistic for testing the nested and interaction effects. However powers of the FR statistic for testing the nested and interaction effects rather than the main effect are greater in a relative size than powers of F statistic for the all population distributions.

• Journal of Ocean Engineering and Technology
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• v.25 no.4
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• pp.36-41
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• 2011

In the present paper, a direct forcing/fictitious domain (DF/FD) level set method is proposed to simulate the FSI (fluid-solid interaction) in two-phase flow. The main idea is to combine the direct-forcing/fictitious domain (DF/FD) method with the level set method in the Cartesian coordinates. The DF/FD method is a non-Lagrange-multiplier version of a distributed Lagrange multiplier/fictitious domain (DLM/FD) method. This method does not sacrifice the accuracy and robustness by employing a discrete ${\delta}$ (Dirac delta) function to transfer quantities between the Eulerian nodes and Lagrangian points explicitly as the immersed boundary method. The advantages of this approach are the simple concept, easy implementation, and utilization of the original governing equation without modification. Simulations of various water-entry problems have been conducted to validate the capability and accuracy of the present method in solving the FSI in two-phase flow. Consequently, the present results are found to be in good agreement with those of previous studies.

• Journal of The Korean Association For Science Education
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• v.33 no.7
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• pp.1450-1470
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• 2013

The purpose of this study was to develop elementary science programs that used multi-level instruction and to analyze verbal interaction patterns in science classes that applied these programs. For this study, the 27 children from the fifth grade at B elementary school, located in Gyeonggi-do, were selected and separated into heterogeneous groups of four students. Verbal interactions occuring in two groups during each class were recorded using video. Elementary science programs using multi-level instruction were developed to target a fifth grade second semester 'Lesson 1. Human Body'. This program provided a mission form for each group and evaluation form for each child. A mission form depending on the children's level has different colors and levels of difficulty for questions. The evaluation form is composed of questions suitable for a child's level in reaching the goal with key concepts. The verbal interaction was mostly categorized into the cognitive domain and the affective domain for analysis. The cognitive domain was subdivided into question, response, making solution, receiving opinion, and the affective domain was divided into behavioral participation and students' attitude. Results of study showed that the frequency of the cognitive domain was higher than the frequency of the affective domain. In the cognitive domain, the median-level was of highest frequency in the children. In the affective domain, high-level was of highest frequency in the children. In terms of both the cognitive and affective domains of children, low-level exhibited the lowest frequency. Verbal interaction frequency was no difference between high-level and median level in cognitive and affective aspects, so median-level children were actively participating in activities similarly with high-level children. There were more types of interactions question, response, making solution, students' attitude in the median-low level children's verbal interaction than high-median level children's verbal interaction.

• Journal of the Korean Chemical Society
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• v.61 no.3
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• pp.104-111
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• 2017

In this study, we analyzed verbal interactions in small group science learning using smart devices by the level of prior achievement. Four heterogeneous groups at a coed high school in Seoul participated. Verbal interactions during small group science learning were audio- and video-taped, transcribed, and analyzed. Verbal interactions were analyzed at the levels of a turn and an interaction unit. The results revealed that the frequencies of verbal interactions were high in task category, especially at information explanation, information question, and reflection on standards subcategories. Furthermore, the frequencies of high-level students at direction explanation, reflection on standards and progress subcategories were higher than those of low-level students, and the frequencies of low-level students at direction question and information explanation subcategories were higher than their counterpart. In the analyses of the interaction units, the frequencies in symmetric elaborated interaction were high, especially at cumulative and evaluative subcategories.

• The Korean Nurse
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• v.29 no.5
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• pp.54-68
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• 1991

This study was conducted to provide the basic information for nursing intervention in infant teach. ing and feeding situation. The subjects were 30 pairs of mother and her infant(9 month) who were normally delivered at 3 university hospital in Seoul area. The data collection was conducted by observation using videotaperecord from September 27, 1989 to Feburary 26, 1990 in their home. The measulsement tools used by this researcher were Nursing child Assessment Teaching scale (NCATS) and Nursing child Assessment Feeding Scale(NCAFS) which was developed by Barnard. The higher sum of "yes" score means the higher mother-infant interaction level. Mother-Infant interaction behaviors in both sitution were based on 6 subcategories; sensitivity to cue, response to distress, social-emotional growth fostering, cognitive growth 'fostering, clarity of + cues, and responsiveness to parent. The data collected through above method were analyzed by mean and t-test and the results were as follows. 1. The sum of maternal behavior score was 40.2 out of 50.0 in teaching situation and 37.9 out of 50.0 in feeding situation. Out of the 4 subcategories on maternal behavior in both situation, the highest subcategory was shown by response to infant's distress and the lowest subcategory by cegnitive growth fostering. 2. The sum of infant behavior score was 14.7 out of 23 in teaching situation and 17.9 out of 26 in feeding situation. Out of the 2 categories on infant behavior in both situation, the highest sub categroy was shown by the clarity of infant's cue in both situation. 3. There was a statistical significance between father's educational level and mother-infant interaction in teaching situation; college group was higher than high school group, particulary in category of sensitivity to infant's cue and congnitive growth fostering. 4. There was a statistical significance in teaching situation between mother's educational level and mother-infant interaction;college group was higher than high school group, particulary sensitivity to infant cue, social-emotional growth fostering and cognitive fostering. 5. There was no statistical difference in between parent educational level and mother.infant interaction in feeding situation.situation.

• Clinical Nutrition Research
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• v.12 no.1
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• pp.7-20
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• 2023

Creating a complex balance between dietary composition, circadian rhythm, and the hemostasis control of energy is important for managing diseases. Therefore, we aimed to determine the interaction between cryptochrome circadian clocks 1 polymorphism and energy-adjusted dietary inflammatory index (E-DII) on high-sensitivity C-reactive protein in women with central obesity. This cross-sectional study recruited 220 Iranian women aged 18-45 with central obesity. The 147-item semi-quantitative food frequency questionnaire was used to assess the dietary intakes, and the E-DII score was calculated. Anthropometric and biochemical measurements were determined. By polymerase chain response-restricted length polymorphism method, cryptochrome circadian clocks 1 polymorphism was assigned. Participants were categorized into three groups based on the E-DII score, then categorized according to cryptochrome circadian clocks 1 genotypes. The mean and standard deviation of age, BMI, and high-sensitivity C-reactive protein (hs-CRP) were 35.61 ± 9.57 years, 30.97 ± 4.16 kg/m², and 4.82 ± 5.16 mg/dL, respectively. The interaction of the CG genotype and E-DII score had a significant association with higher hs-CRP level compared to GG genotype as the reference group (β, 1.19; 95% CI, 0.11-2.27; p value, 0.03). There was a marginally significant association between the interaction of the CC genotype and the E-DII score with higher hs-CRP level compared to the GG genotype as the reference group (β, 0.85; 95% CI, -0.15 to 1.86; p value, 0.05). There is probably positive interaction between CG, CC genotypes of cryptochrome circadian clocks 1, and E-DII score on the high-sensitivity C-reactive protein level in women with central obesity.

• Journal of Families and Better Life
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• v.22 no.6 s.72
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• pp.99-109
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• 2004

This study investigated the motivation of the institutional elderly to participate in the leisure programs the participation motivation and their leisure life satisfaction. A survey questionnaire was administered to 265 elderly in an institution for the elderly. The data was analyzed using frequency analysis, factor analysis, and regression analysis. Major findings are as follows: First, the motivation to participate in leisure programs on the part of the institutionalized elderly tended to be more external than internal. Second, regression analysis indicated that the main internal factors that affected participation were health condition, interaction with roommate, gender. education level, and interaction with institution's staff. The major external factors that affected the participation were health condition, interaction with colleagues, gender, and education level. Finally, the results of the regression analysis indicated that the main internal factors that affected the leisure life satisfaction were, intrinsic motivation to participate in leisure programs, interaction with their roommate, gender, and education level.

• Korean Journal of Child Studies
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• v.21 no.3
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• pp.119-131
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• 2000

Three levels(high, medium, low) of maternal language were used to examine the ways in which mothers interact with their children while reading together. Eighty pairs of mothers and their children were observed in their homes. Findings were that mothers made increased use of high level language with increase in children's age and IQ. Mothers' use of high level language was greater for 6-year-olds than for 5-year-olds and use of low level language was greater for 5-year-olds than for 6-year-olds. The more educated mothers used a higher level of language while less educated mothers used a lower level of language. Mothers' use of low level language predicted lower reading ability in children.