• Child Health Nursing Research
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• v.18 no.2
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• pp.60-67
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• 2012

Purpose: This study was done to examine the importance of health promotion behavior for infants and toddlers as perceived by mothers of children in early childhood, and graduate students in nursing and to provide information for health promotion in early childhood. Methods: This study was a cross-sectional survey research study. The participants were 91 mothers of children in early childhood, and 115 graduate students in nursing. Results: The comparisons showed that graduate students in nursing reported higher perception of the importance health promotion behavior for infants and toddlers than did the mothers. In health promotion behavior, the highest score was in the category of safety. Conclusion: Providing information by nurses is necessary to promote health promotion behavior for mothers of children in early childhood. Therefore, it is important for healthcare professionals to develop effective programs for these mothers who want to promote good health promotion behavior in their children.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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• pp.293-296
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• 2004

In this study, to investigate autogenous shrinkage behavior of 120MPa UHSC at early ages, free and restrained shrinkage tests are performed for various strength levels(50MPa, 80MPa, 120MPa). For 120MPa, the effect of fly ash on autogenous shrinkage was also investigated. In order to assess the potential for early-age cracking in concrete and a mixtures susceptibility to shrinkage cracking, restrained ring test was carried out. Test results show that autogenous shrinkage of UHSC was much higher than that of HSC, VHSC and fly ash delayed cracking age in UHSC by decreasing autogenous shrinkage.

• Journal of the Korea institute for structural maintenance and inspection
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• v.3 no.3
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• pp.129-137
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• 1999

Reinforced concrete structures using early age concrete were result in the degradation of structural performance due to crack, overload, unexpected vibration and impact load. It demands urgently that reinforced concrete structure using early age concrete should be improved the serviceability and structural performance with the application of new fiber materials. Therefore specimens, designed by the test varibles, such as with or without stirrup and percent of steel fiber incorporated, were constructed and tested to evaluate and develop the structural performance of reinforced steel fiber concrete beam. Based on the test results reported in this study, the following conclusions are made. Specimens, designed by the over 0.75% of steel fiber incorporated, were showed the ductile behavior and failed slowly with flexure and flexure-shear. Comparing with the load-displacement relationship of specimen BSS, designed by the recommendations of the Ministry of Construction and Transportation, reinforced steel fiber concrete beam using early age concrete, over 0.75% of steel fiber incorporated, gets enough load carrying capacity and ductility. Increasing the percent of steel fiber incorporated(0.25~2.0%), the ultimate shear stress of each specimen were increased 12~40% than that of control specimen SSS.

• Advances in concrete construction
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• v.11 no.4
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• pp.335-345
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• 2021

It is known from the literature that there are relatively few studies on the engineering properties of ultra-high performance concrete (UHPC) in early age. In fact, in order to ensure the safety of UHPC during construction and sufficient durability and long-term performance, it is necessary to explore the early behavior of UHPC. The test parameters (test control factors) investigated included the percentage of cement replaced by silica fume (SF), the percentage of cement replaced by ultra-fine silica powder (SFP), the amount of steel fiber (volume percent), and the amount of polypropylene fiber (volume percentage). The engineering properties of UHPC in the fresh mixing stage and at the age of 7 days were investigated. These properties include freshly mixed properties (slump, slump flow, and unit weight) and hardened mechanical properties (compressive strength, elastic modulus, flexural strength, and splitting tensile strength). Moreover, the effects of the experimental factors on the performance of the tested UHPC were evaluated by range analysis and variance analysis. The experiment results showed that the compressive strength of the C8 mix at the age of 7 days was highest of 111.5 MPa, and the compressive strength of the C1 mix at the age of 28 days was the highest of 128.1 MPa. In addition, the 28-day compressive strength in each experimental group increased by 13%-34% compared to the 7-day compressive strength. In terms of hardened mechanical properties, the performance of each experimental group was superior to that of the control group (without fiber and without additional binder materials), with considerable improvement, and the experimental group did not produce explosive or brittle damage after the test. Further, the flexural test process found that all test specimens exhibited deflection-hardening behavior, resulting in continued to increase carrying capacity after the first crack.

• Journal of the Korean Home Economics Association
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• v.43 no.3 s.205
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• pp.185-197
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• 2005

The purpose or this study was to investigate the effects of children's internal (age, sex, self-respect) and external (maternal belief, childrearing behavior) variables on self-regulation. The subjects were 2004-and-5-year-olds, their mothers, and teachers. Children's age, sex, and self-respect had m influence on self-regulation; that is 5-year-olds were higher than 4-year-olds for behavioral self-regulation, girls were higher than boys for cognitive and behavioral self-regulation, and the high self-respect group was higher than the low self-respect group for cognitive self-regulation. The psychological controlling and externally directed strategies had a negative influence on children's self-regulation. Maternal affectionate childrearing behavior had an influence on children's self-regulation; that is the high affectionate group had children with higher self-regulation.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.11a
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• pp.781-784
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• 2005

Concrete structures often present volumetrical changes particularly due to thermal and moisture related shrinkages. Volumetric instability is detrimental to the performance and durability of concrete structures because structural elements are usually restrained. These restrained shrinkages develope tensile stresses which often results in cracking in combination with the low fracture resistance of concrete. Early-age defects in high-performance concrete due to thermal and autogenous deformation shorten the life cycle of concrete structures. Thus, it is necessary to examine the behavior .of early-age concrete at the stages of design and construction. The purpose of this study was to propose a shrinkage models of VES-LMC (very-early strength latex-modified concrete) at early-age considering thermal deformation and autogenous shrinkage.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.741-744
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• 2008

Quality control of early age concrete significantly influences the long term performance. Primary factors for early age concrete quality control should include the relative humidity and temperature variation, and these are more important as structures become massive and huge. Temperature raise due to cement hydration causes stress, which can develop to cracking with internal and/or external restraints. Exposure conditions including ambient temperature, humidity and wind also significantly affect the cracking behavior of early age concrete. Among many of studies on the early age concrete behavior, investigation on the variation of temperature and relative humidity internal of concrete is not common. That is in part because the difficulties in measuring the relative humidity and temperature inside the concrete. This study used a digital sensor with an appropriate logger to measure internal temperature and relative humidity. This direct measuring method is expected to provide more reliable and comprehensive data acquisition on the early age behavior of concrete.

• Magazine of the Korea Concrete Institute
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• v.6 no.4
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• pp.56-63
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• 1994

• Korean Journal of Child Studies
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• v.28 no.6
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• pp.183-199
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• 2007

This longitudinal study investigated developmental changes in temperament and examined social adjustment problems by early temperamental characteristics and developmental patterns of temperamental change during infancy. Subjects were 153 six-month-old infants and their mothers. Infant temperament and toddler's problem behavior were measured by the Infant Behavior Questionnaire-Revised (Garstein & Rothbart, 2003) and the Toddler Behavior Checklist (Larzelere et al., 1989), respectively. Results showed that distress to limitations, high pleasure, perceptual sensitivity, and approach increased with age, while activity level, cuddliness, and vocal reactivity decreased. Infants with high scores in activity level, fear, sadness, and approach at 6 months showed more problem behaviors at 18 months. Infants showing abrupt developmental change of high pleasure and perceptual sensitivity developed more negative behavior.

• International Journal of Human Ecology
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• v.12 no.1
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• pp.15-24
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• 2011

This study investigated childhood eating behavior, the influence of eating behavior on the positive and negative emotionality of children, and the pattern or eating behavior influence on emotionality depending on the age and gender of children. A total of 202 children (ages 5 to 7) were selected from 3 nurseries and 1 kindergarten ill Seoul and the survey data responses from teachers were analyzed. The results were as follows. First, children with higher levels of eating behavior showed a higher positive emotionality score compared to those with lower levels of eating behavior. The effect of gender was not significant and positive emotionality tended to increase in the 5 and 6 year old groups as the level of eating behavior increased; in addition, it was generally similar in the 7 year old group. Second, the children with lower level, of eating behavior showed a higher negative emotionality score compared to those with higher levels of eating behavior. The main effects by age and gender were insignificant; however, the interaction of age and eating behavior affected the negative emotionality of children. The eating behavior of children affects emotionality and children with better eating behaviors showed more positive emotional responses and less negative emotional responses in the same circumstances.