• Korean Journal of Childcare and Education
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• v.19 no.2
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• pp.87-117
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• 2023

Objective: This study aimed to develop a documentation model that can support early chlildhood learning through play and facilitate the implementation of early childhood and play-oriented curriculum. Methods: This study utilized the design and development research methodology to derive components for the model through literature review and investigation research. In addition, the model was gradually improved through the 3rd expert review, and the validity of the model was verified through usability evaluation with 10 early childhood teachers. Results: This study identified 13 components and developed a flexible, selective, repetitive, and cyclic documentation model based on the 2019 revised Nuri curriculum. Model development is embodied and presented as a model-detailed model-detailed content. The model is presented in detail in the study. Conclusion/Implications: The documentation model developed in this study is expected to provide guidance to early childhood teachers and serve as a basis for future research on documentation in early childhood education. It is expected that it will be able to present the practical direction of records for play support for teachers in the field.

• Toxicological Research
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• v.18 no.2
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• pp.167-174
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• 2002

Historical control data have been shown to be valuable in the proper interpretation and validation of reproductive toxicology studies. The present data were compiled from rat fertility and early embryonic development studies conducted at Korea Institute of Toxicology during the 1994∼2001 period. These data were assembled in order to provide background information for the general and reproductive data collected in 11 fertility and early embryonic development studies using Sprague-Dawley rats obtain-ing from the Breeding Facility, Korea Institute of Toxicology, Korea. A total of 274 males and 274 females were used in these studies during the eight-year period. Parameters of fertility and early embryonic development included clinical sign, body weights, food consumption, organ weights, estrus cycle, copulation index, precoital time, fertility index, pregnancy index, sperm parameters, and early embryonic development parameters. Most of the values were comparable to the previous historical control data reported by other investigators. These data can be wed not only as a historical data base for the meaningful interpretation of data from reproductive and developmental toxicity studies, but also as a contribution to biological characterization of Sprague-Dawley rats.

• Korean Journal of Plant Taxonomy
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• v.49 no.1
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• pp.1-7
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• 2019

Early leaves within the Viola albida complex were investigated by scanning electron microscopy in order to determine the morphological segments during morphogenesis. The early leaf development of V. albida var. albida could be morphologically divided into the eight stages in the following order: I, the initiation of shoot germination; II, the conical growth directionally of the leaf; III, the adaxial and abaxial formation of the leaf; IV, the initiation of the stipule; V, the formation of a transitional zone between the leaf blade and petiole; VI, the expansion of the upper part of the leaf blade; VII, the formation of almost all parts of the early leaf; VIII, the early simple leaf. Viola albida var. takahashii differs from V. albida var. albida by additional stages, i.e., V-1, the initiation of the first lateral lobe at the both lateral parts of the leaf after the stage V and an early lobed leaf. Viola albida var. chaerophylloides is also distinguished from two taxa by two developmental features, V-2, the initiation of a second lateral lobe below of the first lateral lobe, and an early palmately compound leaf. These findings suggest that the Viola albida complex would be in the process of peramorphosis, showing developmental changes in a chain of events, leading to a different leaf shape. These data would also be useful for isolating genes that give rise to different leaf morphogenesis outcomes among the taxa in the Viola albida complex.

• Nuclear Engineering and Technology
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• v.45 no.3
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• pp.393-400
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• 2013

Concrete undergoing early frost damage in cold weather will experience significant loss of not only strength, but also of permeability and durability. Accordingly, concrete codes like ACI-306R prescribe a minimum compressive strength and duration of curing to prevent frost damage at an early age and secure the quality of concrete. Such minimum compressive strength and duration of curing are mostly defined based on the strength development of concrete. However, concrete subjected to frost damage at early age may not show a consistent relationship between its strength and durability. Especially, since durability of concrete is of utmost importance in nuclear power plant structures, this relationship should be imperatively clarified. Therefore, this study verifies the feasibility of the minimum compressive strength specified in the codes like ACI-306R by evaluating the strength development and the durability preventing the frost damage of early age concrete for nuclear power plant. The results indicate that the value of 5 MPa specified by the concrete standards like ACI-306R as the minimum compressive strength to prevent the early frost damage is reasonable in terms of the strength development, but seems to be inappropriate in the viewpoint of the resistance to chloride ion penetration and freeze-thaw. Consequently, it is recommended to propose a minimum compressive strength preventing early frost damage in terms of not only the strength development, but also in terms of the durability to secure the quality of concrete for nuclear power plants in cold climates.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.1
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• pp.417-424
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• 2017

This study investigated the relationship between pre-service early childhood teacher's metacognition and emotional intelligence on character development efficacy. The subjects were 218 pre-service early childhood teachers at university. A questionnaire, which required self-reporting by these teachers, was used to investigate the effect of their metacognition and emotional intelligence on character development efficacy. The data were analyzed by Pearson's correlation and stepwise regression. The study results were as follows. First, metacognition and emotional intelligence exerted an effect on the character development efficacy of pre-service early childhood teachers. Second, there were significant positive correlations between the metacognition and character development efficacy of the teachers. Third, there were significant positive correlations between the emotional intelligence and character development efficacy of the teachers. Fourth, emotional comprehension of others, emotional comprehension of own, error correction, and emotional activity were meaningful and influential variables on the teachers' self-leadership. These results increased the perception for the development of pre-service early childhood teacher curriculum about character development efficacy, metacognition and emotional intelligence of pre-service early childhood teachers.

• Journal of Industrial Convergence
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• v.18 no.5
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• pp.102-107
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• 2020

The purpose of this study is conduct development and assessment of the on-site customized education program in college curriculum with utilizing Living Lab. The development process is conducted in Living Lab's mechanism ; idea expression, setting agenda, actual activities, and feedback. The developed early education program is constructed four subjects, sixteen sub themes, and fifty three activities. For the assessment of the program, the satisfaction survey was conducted to sixty eight teachers who work for early education institutes in Busan, S. Korea. In the result, more than 80% of respondents answered that the program was satisfying. The study is meaningful as a basic data to utilize Living Lab in various subjects and majors in college.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.641-644
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• 2008

The strength of concrete is developed by cement hydration reaction influenced by the circumferential temperatures. In this study, therefore, the experiments are conducted and evaluated about the characteristics as changes of early concrete placing temperature and curing temperature to understand the effects of the temperature which influences concrete properties. The results of the experiments changing the early concrete placing temperature in 5$^{\circ}C$ and 10$^{\circ}C$ are followed. In case of conducting standard concrete curing, early compressive strength development rate of the concrete which had low placing temperature was low, but it was shown that early compressive strength development rate was not affected by low placing temperature in age 28 days of concrete. In case of conducting outdoor curing in winter, early compressive strength development rate of the concrete which had high placing temperature was high in all test specimens. As a results, early compressive strength development of concrete was influenced by temperature of early concrete, but after aging 28 days of concrete, it was influenced by curing temperature rather than temperature of early concrete.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.05a
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• pp.43-48
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• 2001

The use of fly ash in cement and concrete industries has many benefits including engineering, economic, and ecological aspects. However, it has a disadvantage of low strength development, especially at early ages. In this study, in order to overcome this problem, the early strength accelerating agent($NA_{2}$ $SO_{4}$) was selected and applied to the production of high strength concrete(HSC) containing fly ash. It was found that the compressive strength of fly ash concrete incorporating TEX>$NA_{2}$ $SO_{4}$ has greater than that of concrete containing fly ash only until 7 days after casting. From the microstructural point of view, ettringite increased and pores decreased in fly ash concrete incorporating TEX>$NA_{2}$ $SO_{4}$ , leading to the development of early age strength. It was also found that the velocity vs. strength relationship of HSC is considerably different from that of low-strength concrete(LSC). Therefore, in order to predict early age strength of HSC, a estimation equation different from that for LSC is needed.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05b
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• pp.309-312
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• 2005

Admixture compounds for shortening setting time and accelerating early strength development of EVA polymer powder-modified mortars were made by mixing various quick setting agents. As a result, the quick setting agents contribute to strength development of the mortars in the early curing age of 168h or less. In the viewpoint of early strength development of EVA polymer powder-modified mortars, an quick setting agent content of 20$\%$ is recommended. Early strength of EVA polymer powder-modified mortars expresses the excellent strength with 5$\%$, 10$\%$ of rates of polymer mixing. The rate of polymer mixing was able to be adjusted and flexural strength which is a predeterminded initial strength was also able to satisfy 3MPa(s).

• Magazine of the Korean Society of Agricultural Engineers
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• v.43 no.5
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• pp.124-131
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• 2001

The shrinkage properties of high early strength concrete were investigated. One of the method to control microcrack and crack development due to restrained shrinkage is to reinforce concrete with randomly distributed fibers. Regulated-set cement and two different types of fiber were adopted. The experiments for heat of hydration, drying and autogenous shrinkage were conducted. The desirable resistance of high early strength fiber reinforced concrete to restrained shrinkage microcracking was achieved. These results indicate that use of fiber in high early strength concrete plays an important role in control of crack development due to restrained shrinkage.