• Journal of the Korean Society for Precision Engineering
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• v.12 no.9
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• pp.59-65
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• 1995

The cam is used to a main component in a variety of automatic machines and instruments. To meet the demand of a complicated operation and of reducing weight for automatic machine, Curve Blending Technology, in which each of the basic curves suitable for individual interval is connected, is used for the cam design. In the curve blending, it is necessary to select appropriate elementary curve for each interval and to confirm the dynamic continuity at connecting points between adjoining elementary curves. This paper represented the elementary curve selection method to select an appropriate curve for each interval, and executed computation for the follower displacement and angular displacement of each interval. The paper made an analysis and examine closely for elementary curves to synthesizing curve blending, and it performed dynamic conditions clearly at every points on the cam motions. Therefore the curve blending technology presented by the paper turned into easier work.

• Journal of the Korean Institute of Educational Facilities
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• v.19 no.3
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• pp.3-12
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• 2012

Owing to generalization of design competitions since 1990s, various design methods was tried in elementary middle high school design competitions. Therefore, to analyze design characteristics of elementary middle high school is very meaningful. In this context, this study is the most important purpose for analyzing layout plans and their trends in prizewinners of elementary middle high school design competitions and for furnishing basic datum for next school design. The result of this study is following : (1) The layout patterns of school buildings are classified into 12 types. (2) Entrance design is divided into 6 types(structure, column and wall, open, half structure, general, and mixed type). (3) Square design is grouped into 7 types. (4) Pedestrian mall is sorted out 6 types(straight lineal, curve, curve and square, straight lineal and curve, and straight lineal and curve and square type). (5) Entrance types of vehicle and pedestrian are classified into 4 types(parallel, ㅡ separation, ㄱ separation, and opposite separation type) Analysis shows that the best applying for layout patterns of school buildings is ㄷ type and ㅌ type, for entrance design is structure type, for square design is ${\square}$ type and ${\bigcirc}$ type, for pedestrian mall is straight lineal and square type, and for entrance types of vehicle and pedestrian is parallel type.

• Physical Therapy Korea
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• v.7 no.3
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• pp.1-18
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• 2000

The present study was performed to investigate the prevalence rate of idiopathic scoliosis and to determine the effect of exercise training on scoliotic angle in elementary school children. In this study, two out of five elementary schools in Seosan city were chosen by random sampling. Seven hundred sixty four students (from four grade to the sixth grade student) were selected in two schools. Screening tests were conducted to find idiopathic scoliosis. Among the 764 individuals, 139 subjects who showed positive sign in physical examination took whole spine radiography. Thirty six subjects who had a curve of 10 or greater and consented to participate in the exercise program were selected for the exercise program. The exercise program was performed four times a week for 5 months. The results of this study were as follows: 1) One hundred thirty nine subjects showed positive sign in the scoliosis screening test. 2) The overall prevalence of curve of $10^{\circ}or$ greater in X-ray finding was 8.15%. The prevalencies of curve of $10^{\circ}or$ greater in male and female were 7.1% and 9.2%, respectively. 3) Scoliosis curves were observed at thoracic area (48.4%), at thoracolumbar area (27.4%) and at lumbar area(24.4%). 4) Right side curve was 59.7%, and left side curve was 40.3%. 5) After the 5 month exercise program for scoliosis, the Cobb's angle was significantly decreased. 6) There was no significant difference of Cobb's angle change respect to sex, grades, and scoliosis curve site. Results shown here indicates that an early detection and early exercise for scoliosis can result in decreased the Cobb's angle in elementary school children.

• East Asian mathematical journal
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• v.26 no.4
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• pp.447-461
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• 2010

Papert [17] introduced the LOGO environment in which we make a curve using LOGO commands (FORWARD, ROTATE). We call this geometry as turtle geometry. This environment has influenced many researchers and designers of computers and mathematics education. But the curve that we can make using LOGO command is elementary or too difficult. Polygon and circle is elementary and making other curves is difficult. In this paper, we introduce the method of drawing some other curves mediating new command. First, we study epicycloid and hypocycloid in the historical and the physical context. And we introduce the method of making epicycloid and hypocycloid using vector addition. Next we study the polygon patterns of this curve. Finally, we extend the method for making more general curve and we improve the computer environment using this metaphor.

• Journal of the Korean School Mathematics Society
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• v.16 no.1
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• pp.201-217
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• 2013

This study intends to develop and apply elementary mathematics program for gifted students based on a 'constant width shape' in order to keep pace with the STEAM education which is becoming the main issue and therefore, it set up research subject as follows; To introduce constant width shapes through 'a circle' which is a constant width shape under present education process and based on this, to search a theory about constant width shapes and reuleaux triangles. To arrange an elementary mathematics program for gifted students according to the part 3 enrichment study model of Renzulli. To revise supplement the program on the basis of field application result twice and then to materialize the program. It is expected that the developed program and study data will suggest mathematical ideas and direction of materials development in education sites of elementary mathematics program for gifted students.

• Journal of the Korean Society of Earth Science Education
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• v.9 no.3
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• pp.292-308
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• 2016

The purpose of this study was to find out the effects of climate change education program focused on the keeling curve activities highlighting inquiry process on elementary students' climate literacy. Most of the students have not been able to correctly understand just how serious phenomenon that the temperature rise of the last 100 years is. As a result, there is educational limitations in order to bring about a substantial change in the attitudes toward climate change. So the development program was applied to various questions and explored strategies in order to compare with past climate change data. The results described that 46 students in the experimental group had statistically significant effects on cognitive domain, critical thinking of affective domain and practical domain. In addition, as a result of the analysis of teachers' instructional perspectives and students interview, they supported the researcher's opinion that the developed program could help students improve the climate literacy.

• Journal of the Korean Mathematical Society
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• v.52 no.2
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• pp.225-237
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• 2015

In this article, we show that many of the genera that Giulietti and Fanali obtained from subfields of the GK curve can be obtained by using similar techniques used by Garcia, Stichtenoth and Xing. In the meantime, we obtain some new genera from the subfields of GK and generalized GK function fields.

• Korean Journal of Child Studies
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• v.30 no.2
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• pp.43-55
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• 2009

This study investigated trajectories of change in the career maturity of elementary school students and of attachment to parents and academic achievement as predictors of change. The 2844 participants were 1524 boys and 1320 girls in the Korea Youth Panel Survey. They were fourth graders in 2004 and became seventh graders in 2007. Latent growth curve modeling indicated that : (1) Trajectories of change in career maturity from fourth grade to seventh grade modeled quadratic growth. (2) Variance of career maturity in initial levels, linear slope and quadratic slope indicated individual differences intrajectories of change in career maturity. (3) Attachment to parents influenced initial levels of career maturity academic achievement influenced both initial levels and linear slope of career maturity.

• Journal of the Korean Home Economics Association
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• v.48 no.5
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• pp.25-48
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• 2010

The purpose of this study was to employ the Latent Growth Curve Model(LGM) to investigate the developmental trajectories of children's internalizing and externalizing problem behaviors and to identify predictors that might have an effect on change and the level of developmental trajectories. Furthermore, we classified the developmental trajectories of children's internalizing and externalizing problem behaviors, and also analyzed factors which caused differences in developmental trajectories by Semi-Parametric Group-based Modeling. This study used data from wave 1-4(2004~2008) of elementary school fourth grade panel of the Korea Youth Panel Survey(KYPS). The results showed that children's internalizing and externalizing problem behaviors changed significantly from the fourth grade of elementary school to the first grade of middle school. The predictors for developmental trajectories of children's internalizing problem behaviors were gender, self-control, parental conflict, deviant peers, and attachment to teachers. The predictors for the developmental trajectories of children's externalizing problem behaviors were gender, self-esteem, self-control, and deviant peers. The developmental trajectories of children's internalizing problem behaviors was classified into three groups. The developmental trajectories of children's externalizing problem behaviors was classified into four groups.

• Journal of the Ergonomics Society of Korea
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• v.21 no.3
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• pp.59-79
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• 2002

The purposes of the study were to present the optimum slacks pattern for elementary school girls and to compare and evaluate wearing ease of the slacks. 3D scans using the Cyberware PS motion platform were carried out for 3 subjects who have different body type. The automatic drafting method was programmed by AutoLISP in CAD. Wearing tests using 3D Scanner was done for evaluation of fitness of slacks. Regression analysis, analysis of variance and post-hoc test were performed for statistical analysis of the data by SPSS program. The procedure and results were as follows: The slacks construction components for pattern drafting were derived from 10 horizontal section maps obtained from 3D scans. The automatic drafting was based on the measurements of slacks construction components and the curve of crotch line. The crotch line was drafted using of the arc function in AutoCAD. The total crotch length was calculated using the multiple regression equation. Wearing test represented that the slacks pattern developed to accomodate individual body measurements was estimated more highly than existing patterns.