• Proceedings of the Korea Concrete Institute Conference
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• 2002.10a
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• pp.809-814
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• 2002

Recently, the properties of early-age concrete are increasingly important because these properties directly influence the behavior of early-age concrete structures including stress and cracking behavior. Nevertheless, the studies on early-age concrete are limited to strength and temperature development. The purpose of present study is to propose a simple and rational method which can predict the stress and strain behavior of young age concrete. A series of test have been done to measure the temperature development, strains and stresses in concrete members. The concept of equivalent age was used to define the degree of hydration and this degree of hydration was used to calculate the strength and elastic modulus. The critical degree of hydration and thermal expansion coefficient were calculated using experimental data. It is seen that the critical degree of hydration range from 0.05 to 0.11 based on the measuring method. The thermal expansion coefficient was calculated based on the measured non-mechanical strain and it is found that the coefficient decreases slightly with the increase of age. The consideration of critical degree of hydration in calculating stresses gives more accurate results. The present study provides useful method and data in evaluating early-age behavior of concrete structure.

• The Korean Journal of Ecology
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• v.17 no.2
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• pp.120-130
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• 1994

Stages of vegetation development on talus area were studied to examine temporal changes in species composition and vegetation structure, and to elucidate the mechanism of early patch formation. While ground coverage of lichens, which may form substrate for moss colonization and mitigate the heat-stress on rocks, decreased gradully, coverage of mosses increased slightly during primary succession. Ecological role of mossess related with water retention in community may be very important not only at pioneer stage but also at later stages because of little soil development on this talus area. Species diversity and species richness increased during the early stages of succession. Parthenocis년 tricuspidata and Sorbaria sorbifolia var. stellipa dominated in liana stage, Ulmus davidiana for. suberosa and Lindera obtusiloba in shrub stage, and Fraxinus rhynchophylla and Actinidia arguta in subtree stage, however, was composed of mixed forest of several tree species. U. davidiana for. suberosa, L. obtusiloba, Securinega suffruticosa and Rhus chinensis were relatively important woody species in early patch forming process. The results, however, suggested that early establishment on talus area might be strongly associated with chance for safe-site because both pioneer species and later species could take part in early patch forming process.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.2440-2443
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• 2005

We propose a new early rehabilitation training system for postural control using a tilting bed and a force plate. The conventional rehabilitation systems for postural control cannot be applied to the patients lying in bed because the rehabilitation training using those systems is possible only when the patient can stand up by himself or herself. Moreover, there has not existed any device that could provide the sense of balance or the sensation of walking to the patients in bed. By using a tilting bed, a visual display, and a force plate, we have developed a new rehabilitation training system for balance control of the patients in bed providing sense of balance and the sensation of walking to the patient. Through the experiments with real people, we verified the effectiveness of the new early rehabilitation training system. The results showed that this system is an effective system for the early rehabilitation training and that our system might be useful as clinical equipment.

• Human Ecology Research
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• v.58 no.2
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• pp.163-176
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• 2020

Longitudinal studies have shown mixed findings on the association between body image dissatisfaction and self-esteem among adolescents. This study examined the longitudinal, reciprocal influences between body image dissatisfaction and self-esteem among Korean pre- and early adolescents by using nationally representative longitudinal panel data from the Korean Youth Panel Study (KYPS). Analyses based on 2,230 participants indicated that girls' body image dissatisfaction was significantly higher than boys'. The trajectory of body image dissatisfaction increased sharply during pre- and early adolescence, but stabilized afterwards for both boys and girls. Self-esteem deteriorated rapidly initially, but began to recover as adolescent girls and boys matured. Structural equation modeling showed that reciprocal influences between body image dissatisfaction and self-esteem were detected for boys. Body image dissatisfaction among girls predicted self-esteem during the entire period, while the opposite direction from self-esteem to body image dissatisfaction emerged two years later. The present study found that, during pre- and early adolescence, body image dissatisfaction and self-esteem develop in a circular fashion by forming a vicious cycle. Implications for the development of intervention and prevention programs are discussed in consideration of age and gender.

• Korean Journal of Remote Sensing
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• v.28 no.6
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• pp.653-660
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• 2012

This study classified paddy fields according to rice varieties and monitored temporal changes in rice growth using SAR backscatter coefficients (${\sigma}^{\circ}$). A growing period time-series of backscatter coefficients was set up for nine fine-beam mode RADARSAT-1 SAR images from April to October 2005. The images were compared with field-measured rice growth parameters such as leaf area index (LAI), plant height, fresh and dry biomass, and water content in grain and plants for 45 parcels in Dangjin-gun, Chungnam Province, South Korea. The average backscatter coefficients for early-maturing rice varieties (13 parcels) ranged from -18.17 dB to -6.06 dB and were lower than those for medium-late maturing rice varieties during most of the growing season. Both crops showed the highest backscatter coefficient values at the heading stage (late July) for early-maturing rice, and the difference was greatest before harvest for early-maturing rice. The temporal difference in backscatter coefficients between rice varieties may play a key role in identifying early-maturing rice fields. On the other hand, comparisons with field-measured parameters of rice growth showed that backscatter coefficients decreased or remained on a plateau after the heading stage, even though the growth of the rice canopy had advanced.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2006.11a
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• pp.91-94
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• 2006

The way to shorten a construction period is considered to an very important technology development element as reducing the formwork removal periods with promoting strength revelation own concrete. This study executed experiment to review usability of early strength revelation chemical admixture which is judged in ways effective with premature removal of form about concrete. Use of early strength revelation AE water reducin admixture is apperaing so that strength revelation by early hydration promotions is excellent. The results of being applied proposed work process are that compressive strength are appeared more than 5MPa within 16 hours so that removal of vertical form was possible. the concrete compressive strength satisfied with a more than 2/3 of specified concrete strength for removal of horizontal form are appeared in 42 hours of 27 MPa proportioning strength, in 36 hours of 30, 35 MPa proportioning strength so that the 6 days cycle time of concrete structural frame work is cut by 2 days as shortening delayed period in works of removing slab forms. So construction cost reductions and a construction period shortening are judged so that it is possible.

• The Journal of the Convergence on Culture Technology
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• v.9 no.1
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• pp.281-286
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• 2023

We aimed to find out how teaching ethics and empathy affect the perception of children's rights with 297 pre-service early childhood teachers enrolled in the Department of Early Childhood Education at universities located in Busan. Through this, the purpose of this study was to present basic data for the development of a character development program for a high-quality early childhood teacher training institution. We derived the following research results. First, as a result of examining the degree of recognition of pre-service early childhood teachers' teaching ethics, empathy, and awareness of children's rights, the average value was high in the order of teaching ethics, awareness of children's rights, and empathy. Second, there was a positive correlation between pre-service early childhood teachers' empathy ability, teaching ethics and awareness of children's rights, and empathy ability and awareness of children's rights. Third, as a result of examining the relative effects of teaching ethics and empathy of pre-service early childhood teachers on the recognition of children's rights, social ethics was found to be the strongest predictor among teaching ethics. In this study, we identified that teaching ethics and empathy are effective in various approaches to promote awareness of children's rights in pre-service early childhood teachers. And the results of this study provides the basic data for the character development of desirable teachers that pre-service early childhood teachers should have.

• Korean Journal of Child Studies
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• v.3
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• pp.83-96
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• 1982

TV has a very strong influence on various aspects of children's life and development. In view of this influence, various problems related to the content and production of TV programs for early - childhood deserve a careful study. Recognizant of this significance, this study aims to suggest the direction in which the production of TV programs for early childhood in Korea will steer by defining the concept of TV programs for early childhood and by analyzing the current status and trends of producting TV program for early childhood at abroad. In this study, attempts were made to suggest some strategies for the production of TV programs for early childhood based on an expansive literature review. 1. The running time of TV programs for early-childhood ages of 4-5 year old is suggested to be 15 minutes. 2. In the process of producing the programs, a group of professionals including in-service teachers, researchers specializing in child development, psychology and sociology, idea-creators, script writers, media experts, producers, and monitors should provide concerted efforts throughout the process. 3. The running time of TV programs for early-childhood should be less than 20 minutes and therefore should have simple learning objectives. 4. The contents of programs should be organized in such a way as to enable children to view themselves as well as the environment in more positive ways and to fester desirable values and beliefs in them based on various constructive activities and plays. 5. The programs should adopt various techniques including repetition, to ensure the maximum learning effect in full consideration of children's interest. 6. The programs should be continuously revised and supplemented based on the evaluation of the programs, children's responses and monitor's feedbacks.

• Human Ecology Research
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• v.52 no.6
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• pp.639-649
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• 2014

The main purpose of this study was to find the relationship between the delinquency-onset time in the source and the continuity of delinquency. In order to achieve this objective, we divided 350 first-year high school students into three groups early-onset type, late-onset type, and non-delinquent adolescents on the basis of the delinquency onset. The results of this study were as follow: (1) for the boys, the early-onset type shows a higher continuity of delinquency than both the late-onset type and the general adolescents. On the other hand, for the girls, the early-onset type shows a higher continuity of delinquency than the late-onset type, but there was no difference in the persistence duration between the late-onset type and the non-delinquent adolescents. (2) For the boys, the examination reveals that the early-onset type has a higher degree of sensation seeking and impulsivity than the general adolescents. In addition, the early-onset type shows a higher degree of sensation seeking than the late-onset type, whereas the two show no difference in impulsivity. For the girls, sensation seeking did not show any difference depending on the delinquency onset. However, more impulsivity appeared in the early-onset type than in the late-onset type or the non-delinquent adolescents. (3) The relative priorities of variables determining the group to which the students belong on the basis of the delinquency onset are in the order of sensation seeking and juvenile impulsivity. Therefore, this study, suggests that the early-onset type requires a different kind of intervention than the late-onset type.

• Korean Journal of Childcare and Education
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• v.10 no.1
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• pp.147-164
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• 2014

This study aims at analyzing 6 OECD countries' (Australia, New Zealand, Sweden, Norway, England, South Korea) national early childhood care and education curriculum (framework) based on the perspectives of its implementation. Its design and development always focus on how the national early childhood education and care curriculum will be applied in the early childhood settings in a correct and faithful way. As a result, teachers are considered the user or deliverer of the national curriculum rather than the one who interprets it and construct their own curriculum in accordance with their students. Five OECD countries which have achieved an integrated system between early education and care systems, take the constructive view of designing and applying the national curriculum. Accordingly, a national early childhood education and care curriculum within an integrated system should be developed in Korea, in order to accept the constructive view of curriculum development and application.