• Steel and Composite Structures
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• v.13 no.5
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• pp.489-500
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• 2012

Cold-formed steel profile sheets acting as decks have been popularly used in composite slab systems in steel structural works, since it acts as a working platform as well as formwork for concreting during construction stage and also as tension reinforcement for the concrete slab during service. In developing countries like India, this system of flooring is being increasingly used due to the innate advantage of these systems. Three modes of failure have been identified in composite slab such as flexural, vertical shear and longitudinal shear failure. Longitudinal shear failure is the one which is difficult to predict theoretically and therefore experimental methods suggested by Eurocode 4 (EC 4) of four point bending test is in practice throughout world. This paper presents such an experimental investigation on embossed profile sheet acting as a composite deck where in the longitudinal shear bond characteristics values are evaluated. Two stages, brittle and ductile phases were observed during the tests. The cyclic load appears to less effect on the ultimate shear strength of the composite slab.

• The Korean Journal of Applied Statistics
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• v.14 no.2
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• pp.439-448
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• 2001

본 연구는 시간자료(Longitudinal data)의 분석을 위하여 Fuzzy k-means 군집분석 방법을 확장한 알고리즘을 제안한다. 이 논문에서 제안하는 군집분석방법은 각각의 개체에 대응하는 성장곡선에 Fuzzy k-means 군집분석의 알고리즘을 결합하는 것을 핵심아이디어로한다. 분석결과는 생성된 군집을 성장곡선모형으로 표현할 수 있고 또한 추정된 모형의 식을 활용하여 새로운 개체를 분류도 할수 있음을 보인다. 그리고 이 군집분석방법은 아직 자라지 않은 나이 어린 개체가 미래에 어느 군집에 속할 것인가 하는 분류와 함께 이 개체의 향후 성장상태를 예측을 하는 데에도 적용이 가능하다. 제안된 알고리즘을 원숭이(macaque)의 상악동(maxillary sinus)의 자료에 적용한 실례로 보인다.

• Korean Journal of Child Studies
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• v.28 no.5
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• pp.109-126
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• 2007

A sample of 322 18-month-old infants and their mothers were assessed longitudinally at 24 and 30 months. Maternal utterances and styles of linguistic interaction were measured during a 10 minute free play session. Mothers completed a vocabulary checklist for infants. Longitudinal data were analyzed by multilevel modeling. Results indicated that vocabulary increased with age of infants and the growth rate was highly predictable by the size of vocabulary at 18 months. The growth rate was strongly influenced by maternal questioning and feedback. The effect of the maternal linguistic input was constant with age. Gender differences in size of vocabulary did not vary systematically with age.

• The korean journal of orthodontics
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• v.15 no.1
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• pp.93-103
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• 1985

Since the fact was known that mouth breathing resulted from the adenoid hypertropy causes malocclusion, many investigators have studied nasopharynx and adenoid in order to clarify the role in relation to the effect on face and occlustion and the development of airway. The author analyzed 13 items in longitudinal cephalometric roentgenograms of 17 boys and 19 girls taken from the age of 7 to 12. The results were as follows. 1. The means and standard deviation for the measured items were obtained. 2. The continual growth of nasopharyngeal cavity was more affected by the height than the depth. 3. The size of adenoid was larger in males than in females, especially on R, $D-AD_2$. 4. Airway percentage was highest in boys at age 10 and girls at age 9. 5. The items showed significant differentiation between males and females were airway percentage, posterior height, $D-AD_1,\;D-AD_2$, and R.

• Journal of the Korea Institute of Military Science and Technology
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• v.10 no.3
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• pp.173-180
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• 2007

In this paper, we have proposed a simple finite element model for separation mode analysis on the roadwheel and track assembly of main battle tank and established a contact stress-based mechanism which could explain the initiation and growth of separation defect occurred during the test of padreplacable track. It was proved that the longitudinal contact shear stress component on the pin hole region of the track shoe body which is parallel to the driving direction is consistent with the crack initiation at the bonding surface between track shoe and wheel-side rubber. The longitudinal shear stress increased locally near the separated region after the separation initiated. So we could assume that the local stress concentration accelerates the separation growth according to the shear mode.

• Journal of Korea Multimedia Society
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• v.19 no.8
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• pp.1626-1635
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• 2016

This study examines whether online game motivation, with social and expedition needs, are associated with the degree of loneliness among young adolescents. Using data from a survey of 2014 elementary-, middle- and high-school students in South Korea, a three-wave online survey was conducted to collect data from online players. Two latent growth cause-and-effect models were developed to test whether online game motivation influences degree of loneliness. Results showed that both social and expedition needs are positively associated with loneliness. This study contributes to the knowledge of the underlying needs for a player with loneliness and also highlights the social and expedition needs as potential therapeutic factors.

• The Journal of the Korean dental association
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• v.13 no.3
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• pp.221-229
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• 1975

• The Journal of the Korean dental association
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• v.14 no.4
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• pp.367-376
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• 1976

• Journal of the Korean Ceramic Society
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• v.27 no.8
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• pp.1050-1054
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• 1990

Rutile(TiO2) single crystals were grown by FZ method. Feed rod was sintered in the longitudinal tube-shaped furnace at 135$0^{\circ}C$ and optimum growth condition was growth rate 5-8mm/hr, rotation rate 30-40rpm. When crystal was growing, atomosphere was oxidized condition, and grown single crystal was annealed at 110$0^{\circ}C$. The rutile single crystals were oriented to [001] direction and color change of single crystals were related to atmosphere, and difference of electric conductivity and resistance was due to the fact above.

• Korean Journal of Childcare and Education
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• v.12 no.5
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• pp.137-155
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• 2016

The purpose of the present study was to investigate the longitudinal relationship between main caregivers' life satisfaction and depression and self-esteem of school-aged children, and to provide plans for improving the lives of the school-aged children. For this purpose, we analyzed the three years'longitudinal panel data (2011-2013) of the Korean Children and Youth Panel Survey (KCYPS) including 2,342 first grade elementary school children employing the latent growth model using SPSS 18.0 and AMOS 22.0. Analysis results were as follows. First, main caregivers'life satisfaction and school-aged children's depression increased as time passes and linear change model was selected. Second, the initial status of main caregivers'life satisfaction had effects on the initial status of their children's depression, but initial status and rates of change of life satisfaction did not have an influence on the rates of change of the depression. However, it was found that the main caregivers' life satisfaction had effects on the school-aged children's self-esteem and it worked as a mediator on the longitudinal relationship between the main caregivers'life satisfaction and the children's depression. School-aged children's self-esteem was a partial mediator on the initial status of their depression and full mediator on these rates of change. These findings suggests that programs improving school-aged children's self-esteem should be developed.