• Korean Journal of Human Ecology
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• v.13 no.6
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• pp.833-845
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• 2004

This study examines different individual and environmental factors that affect children's self-control. For an analysis, locus of control, perceived competence, and achievement motivation were all included in individual variables. For family variables, mothers' parenting and patents' marriage conflict were examined. For classroom psycho-social environment, teacher support, peer relationship, class involvement, and teachers' supervision were used. The sample consisted of 548 fifth and sixth grade children. Statistics and methods used for the data analysis were Cronbach's alpha, frequency, percentage, Pearson's correlation, and Hierarchical Regression. Several major results were found from the analysis: First, locus of control, perceived competence, and achievement motivation had a positive correlation with children's self-control. Second, mothers' affective parenting had a positive correlation with children's self-control. However, mothers' controlling parenting and parents' marriage conflict had a negative correlation with it. Third, teacher support, peer relationship, and class involvement had a positive correlation with children's self-control. In addition, teacher supervision had a positive correlation with girls' self-control. Fourth, class involvement, locus of control, and academic competence were important variables predicting boys' self-control. On the other hand, Class involvement, achievement motivation, academic competence, teacher's supervision, and mothers' controlling parenting were important variables predicting girl's self-control.

• Journal of the Korean Society of Costume
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• v.33
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• pp.27-39
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• 1997

The purpose of this study was to classify the attributes of brand image criteria of women's shoes to compose the perceptual map of the brand by factor analysis and to examine the differences in brand preferences and purchase methods of shoes according to demographic variables. 10 brand names were selected for the study Samples were 271 women in Seoul Korea :143 were college students and 128 were career women.The data were analyzed using factor analy-sis multiple regression analysis one-way ANOVA Duncan's multiple range test x2-test t-test. The results of the study were the -followings: 1. Four segments of brand image attributes of women's shoes derived by factor analysis: F. 1. 'utility' F.2'appearance' ; F. 3 'sales promotion' ; F.4 'financial factor'. 2. As the result of draw up the perceptual map 'landrover' was high in utility but low in appearance 'Misope' and 'Mook' was low in utility but high in appearance. 'Fashion Leader' was in the nearest ideal direction to the utility and appearance. 3. The preference level of the shoes brand name was in order of the 'Fashion Leader'. 'Mook' and 'Soda' But consumers possessed 'Landrover' the most 4. There were significant differences among preference level of ' Landrover' and 'Misope' according to the social class. There were sig-nificant differences among possession level of 'Misope' and 'Soda' according to the social class 5. the middle and lower class consumers used an exchange ticket during the bargain sales more than upper class when they pur-chase shoes.

• The Mathematical Education
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• v.54 no.4
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• pp.335-350
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• 2015

The purpose of this study was to investigate the effectiveness of the differentiated instruction in mathematics by a meta-analysis. Among the studies conducted for last twenty three years, the relevant 49 research articles were selected, 80 effect sizes were calculated for the cognitive domain and 70 effect sizes for the affective domain. Effect sizes were analyzed with school levels, student level, group organization method such as homogeneous vs. heterogeneous, class transfer and adjusting class sizes for each cognitive domain and affective domain. The results are as the followings: In the cognitive domain, the overall effect size of the differentiated instruction produced a medium effect(effect size=0.68, U3=75.17%). The differentiated instruction showed the highest effect size on elementary school and middle school, mid level students, heterogeneous group, class transfer and not adjusted class size. And in the affective domain, the overall effect size of the differentiated instruction produced a low effect(effect size=0.36, U3=65.36%). The differentiated instruction showed the highest effect size on elementary school, mid level students, and heterogeneous group. Thus the differentiated instruction was proved to be effective in mathematics classes.

• The KSFM Journal of Fluid Machinery
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• v.15 no.3
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• pp.5-11
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• 2012

This study is to develop a 1kW-class horizontal axis wind turbine(HAWT) rotor blade which will be applicable to relatively low wind speed regions in southwest islands in Korea. Shape design of 1kW-class small wind turbine rotor blade is carried out using a blade profile with relatively high lift to drag ratio by blade element momentum theory(BEMT). Aerodynamic analysis on the newly designed rotor blade is performed with the variation of tip speed ratio. Power coefficient and pressure coefficient of the designed rotor blade are investigated according to tip speed ratio.

• Journal of the Korean Statistical Society
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• v.35 no.4
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• pp.419-439
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• 2006

The article develops a new class of distributions by introducing a nonnegative perturbing function to $t_\nu$ distribution having location and scale parameters. The class is obtained by using transformations and conditioning. The class strictly includes $t_\nu$ and $skew-t_\nu$ distributions. It provides yet other models useful for selection modeling and robustness analysis. Analytic forms of the densities are obtained and distributional properties are studied. These developments are followed by an easy method for estimating the distribution by using Markov chain Monte Carlo. It is shown that the method is straightforward to specify distribution ally and to implement computationally, with output readily adopted for constructing required criterion. The method is illustrated by using a simulation study.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.10
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• pp.1475-1480
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• 2013

In this paper, the basic design study of a water-cooling jacket, which have reported no cases for applying to railway traction motors so far, were conducted for applying to Interior Permanent Magnet Synchronous Motor (IPMSM) for railway vehicles. The basic thermal characteristics analysis of the 110kW-class IPMSM was performed by using 3-dimentional thermal equivalent network method. The necessary design requirements of the water-cooling jacket were derived by analyzing the results of the basic thermal properties. Next, the thermal characteristics analysis technique was established by using the equivalent model of the solenoid-typed pipe to be installed on the inside of the water-cooling jacket for 110kW-class IPMSM. Finally, a design model of 6kW-class water-cooling jacket was derived through the analysis of various design parameters.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.60.2-60.2
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• 2011

This study is to develop a 1kW-class small wind turbine blade which will be applicable to relatively low speed regions. For this blade, a high efficiency wind turbine blade is designed and a light and low cost composite structure blade is adopted considering fatigue life. In this study, shape design of 1kW-class small wind turbine blade for hybrid power generation system is carried out by BEMT(blade element momentum theory). X-FOIL open software was used to acquire lift and drag coefficients of the 2D airfoils used in power prediction procedure. Moreover, pressure and velocity distributions are investigated according to TSR by CFD analysis.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.226-227
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• 2008

We constructed a class I Flextensional transducer, and analyzed the variation of the resonance frequency of the transducer in relation to its design variables. We used the FEM for the analysis. Major axis length, minor axis length, thickness and material properties of the shell have large effects on the resonance frequency. In addition, the validation of the FE model was verified by manufacturing and comparison of the impedance analysis.

• Journal of Fisheries and Marine Sciences Education
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• v.21 no.4
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• pp.499-507
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• 2009

The purpose of this study was to improve teachers' instruction and to identify the characteristics of interaction between teachers and children. Field excellent class instructions, which were known as the best lectures from the competition of an instruction contest in Busan, were video recorded and openly released on the internet. A teacher who won a prize for his excellent teaching at the contest demonstrated a Korean subject class on sixth grade elementary school curriculum. His instruction was analyzed by two coders based on the frame of Flanders' language interaction system. Inter-coder reliability was .967 from Scott's coefficient. From the results of the Flanders index, the major and minor instruction sequences were 4-8-2-5 and 6-0-5-4, and the teacher tended to interact with students by accepting feeling and ideas. These results could provide effective cues and information on how to to improve instruction.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.913-914
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• 2017

Structural analyses of a engine system is required in development stage for increasing structural reliability and reducing weight. Attitude of a launch vehicle during flight is controlled by combustion chamber rotation varying with TVC (thrust vector control) actuator displacements. In this study nonlinear static analysis is performed for a 75 tonf-class liquid rocket engine using before and after the TVC actuation.