• 산업기술연구
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• 제25권B호
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• pp.73-80
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• 2005

Durability of concrete structures is seriously compromised by cracking at early-age concretes, particularly in high-strength or high-performance concrete structures. Since early-age cracking is influenced by various factors that affect the hydration process, early-age shrinkage and stress/strain development, the behavior at early-age is highly complex and no rational methodologies for its control have yet been established. 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.

• 치위생과학회지
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• 제13권2호
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• pp.125-134
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• 2013

본 연구는 유아교사와 어머니들의 구강건강지식, 유아구강건강관리행동, 그리고 구강건강교육에 대한 인식 차를 알아보고자 충북 Y군 유아교사 90명과 어머니 235명을 대상으로 설문조사를 하였으며, SPSS Windows ver. 12.0 (SPSS Inc.)을 이용하여 분석한 결과 다음과 같은 결론을 얻었다. 1. 유아교사들과 어머니들의 구강건강지식정도는 차이가 없었다. 2. 유아교사들은 어머니들에 비해 보다 바람직한 치아우식예방 행동, 칫솔관리행동, 구강위생행동 지도를 하는 것으로 나타났다. 그리고 41%의 어머니들은 유아교육 및 보육 기관에서 실시하는 구강정기검진과 이후의 처치서비스에 대해 무관심하거나 인지하지 못하는 것으로 나타났다. 3. 어머니들은 유아교사들에 비해 구강건강에 대한 관심이 높으나, 유아교사들에 비해 구강건강교육에 대한 경험이 적었다. 어머니들은 유아들의 구강건강관리에 대한 내용으로 구강건강교육을 받기를 원하였고, 유아교사들은 구강건강교육을 위한 지침서와 매체에 대한 구강건강교육을 받기를 원하는 것으로 나타났다. 유아교육 및 보육기관과 가정에서 일관되게 유아를 위해 양질의 구강건강관리를 위해서는 유아교사와 어머니들 모두에게 구강보건교육에 대한 인식을 높이고, 유아구강건강 관리행동의 이행을 위해 올바른 구강건강지식을 전달하고 그들이 부족하다고 생각되는 영역에 대한 내용의 유아구강 보건교육 프로그램 개발이 요구되며, 또한 이들이 이런 프로그램을 손쉽게 접할 수 있는 교육방법 및 매체의 개발도 필요하다고 사료된다.

• Human Ecology Research
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• 제52권5호
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• pp.483-494
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• 2014

The purpose of this study was to investigate the causal relationship of early adolescents' personal variables and social support on their self-esteem by grade. Information on 226 6th graders from elementary schools and 226 1st year students from middle schools in Busan was collected. Early adolescents' prosocial behavior, academic achievement, social support, and self-esteem were assessed using their self-reports. For the data analysis, Cronbach's ${\alpha}$, t -test, Pearson's correlation coefficient, and multiple regression were used. The collected data were analyzed by the SPSS ver. 21.0 program for Windows. The major findings were as follows: first, early adolescents' prosocial behavior, academic achievement, social support demonstrated a significant difference between grades. Second, peers' social support was the most powerful determinant of self-esteem in both the 6th graders from elementary schools and the 1st year middle school students. Third, prosocial behavior had the greatest total effect on self-esteem in the case of both groups of students. The middle schoolers' academic achievement had no causal effect on their self-esteem. The findings from this study indicate that early adolescents' personal variables and social support are important elements that affect their self-esteem differently depending on their grade. Further, the findings of this study can be used as fundamental data to develop a teaching plan and provide counseling for early adolescents in order to increase their self-esteem.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 춘계 학술발표회 논문집(II)
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• pp.657-660
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• 2006

Recently, very-early strength latex-modified concrete(below ; VES-LMC) has been developed for repairing and overlaying the old concrete bridge deck. 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 evaluate the autogenous shrinkage of VES-LMC, having an experimental variables such as retarder and water-cement ratio. The greater the retarder content in VES-LMC, the greater the expansion at early-age. This recommend the small retarder content as possible. The effect of water-cement ratio on early-age behavior is very small, because of the wrapped specimen in order to prevent water evaporation.

• 대한기계학회논문집
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• 제18권7호
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• pp.1722-1729
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• 1994

At early stage of creep-fatigue crack growth tests, initial transient behavior which implies high crack growth rate has been generally observed by some researchers. Since the influence of the initial transient crack growth behavior on the remaining life of components is significant, cause of it should be further studied. In this study, characteristics of the initial transient behavior of 1Cr-1Mo-0.25V steel is studied experimentally by performing creep-fatigue crack growth tests at $538^{\circ}C$ in air under trapezoidal waveshapes. It is verified that the cause of the initial transient behavior is not high ${(C_t)}_{avg}$ values due to the small scale creep condition at the early stage of test, but oxidation-dominated crack growth mechanism during the transient period which is different from the creep-dominated crack growth mechanism in steady crack growth period.

• 한국건강관리협회지
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• 제3권2호
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• pp.189-198
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• 2005

This study examined the applicability of the transtheoretical model(TTM) to understanding exercise behavior of early adulthood. A cross-sectional study was conducted and data wee collected from 1618 adults aged from 20 to 39 through internet survey. Major conclusions wee as follows: 1. Stage distribution for exercise behavior was 15.6%, 26%, 25%, 19%, 14.4% for precentemplation, contemplation, preparation, action, maintenance stages, respectively. 2. Behavioral processes were more frequently utilized than cognitive processes for action and maintenance stage. 3. Self-reevaluation, social liberation and reinforcement were frequently used in precontemplation, contemplation and preparation stages. Self-reevaluation, reinforcement, self-liberation were frequently used in action and maintenance stages. 4. Pros of exercise behavior began to be higher than cons of exercise behavior from the actions stage and continued to increase to maintenance stage. 5. Self-efficacy was higher in action stage than precontemplation, contemplation and preparation stages and the highest in maintenance stage.

• 한국지역사회생활과학회지
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• 제20권3호
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• pp.437-448
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• 2009

The purpose of this study was to examine the effect of individual and interpersonal variables on early childhood teachers' efficacy of problem behavior guidance. Individual variables consisted of teachers' socio-demographic characteristics, experience of training course on problem behavior guidance and warm-hearted attitude. Interpersonal variables consisted of intimacy with colleagues, support from the principal of a kindergarten, parental partnerships. Subjects were 122 early childhood teachers in Busan. Major findings were as follows. There were significant differences in teachers' efficacy of problem behavior guidance with respect to teachers' age, teaching experience, position, marriage status, experience of training course on problem behavior guidance, warm-hearted attitude, intimacy with colleagues, and support from the principal of a kindergarten. In other words, a higher level of teachers' efficacy of problem behavior guidance was shown in the teachers who were older, highly experienced, or in higher positions. In addition, teachers who were married, had completed a training course on problem behavior guidance, had a higher warm-hearted attitude, had a intimacy with colleagues, or had a support from the principal of a kindergarten were found to have higher efficacy of problem behavior guidance. As results of examining relative effects of individual and interpersonal variables on efficacy of problem behavior guidance, the influential variables are teaching experience, warm-hearted attitude, support from the principal of a kindergarten, and position in that order.

• 한국산학기술학회논문지
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• 제22권1호
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• pp.477-484
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• 2021

본 연구는 예비유아교사의 일반적 특성에 따라 건강 지식과 건강 행위, 건강교육 교수효능감에 차이가 있는지를 살펴보고, 각 변인 간의 관계를 분석하여 교수효능감에 영향을 미치는 요인을 알아보는 것을 목적으로 하였다. 이를 위해 충남 지역과 전북 지역 소재 전문대학 유아교육과에 재학 중인 258명을 대상으로 건강 지식, 건강 행위, 건강교육 교수 효능감을 측정하였다. 수집된 자료는 SPSS Win 21.0을 이용하여 연구문제에 따라 t검정과 Welch 분산분석, 상관분석, 중다회귀분석을 실시하였다. 연구결과 첫째, 예비유아교사의 일반적 특성 중 일부 변인에 따라 건강 지식과 건강 행위, 건강교육 교수효능감에 유의한 차이가 있었다. 둘째, 예비유아교사의 건강 행위와 건강교육 교수효능감 전체 및 하위변인 간에는 유의한 정적 상관이 나타난 반면, 건강 지식과 건강교육 교수효능감 간에는 유의한 정적 상관이 거의 나타나지 않았다. 건강교육 교수효능감에 영향을 미치는 변인은 건강 행위 전체였으며 설명력은 약 30%인 것으로 나타났다. 이상의 연구 결과를 토대로 본 연구의 제한점과 후속 연구에 대한 제언을 제시하였다.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2006년도 정기 학술대회 논문집
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• pp.898-905
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• 2006

In the present paper, for a quantitative assessment of early-age cracking in an RC wall, an improved analytical model is proposed. First of all, a three-dimensional finite element model for the analysis of stresses due to hydration heat and differential drying shrinkage is introduced. A discrete steel element derived using the equivalent nodal force concept is used to simulate reinforcing steels, embedded in a concrete matrix. In advance, to quantitatively calculate the cracking potential, an analytical model that can estimate the post-cracking behavior in an RC tension member is proposed Subsequent comparisons. of analytical results with test results verify that the combined use of both the finite element model for the stress analysis as well as the analytical model for the estimation of the post-cracking behavior in an RC tension member make it possible to accurately predict the cracking ,behavior of RC walls.

• 아동학회지
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• 제38권1호
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• pp.17-31
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• 2017

Objective: The purpose of this research was to examine the effects of parents' childhood attachment representations and parenting behavior in developing early childhood self-regulation, a developmental skill. Methods: This research was conducted with 171 preschoolers, 171 parent couples, and 22 teachers of 5-year-old classes in kindergartens and children's houses in Seoul. Results: First, there was significant correlation among parental childhood attachment representations, parenting behavior, and child self-regulation. Second, parental attachment representations and parenting behavior were shown to affect self-monitoring, a subvariable of self-regulation, and were influenced by maternal independence-oriented parenting behavior, maternal attachment representation, and parental attachment representation. As factors affecting self-control, a subvariable of self-regulation, they were influenced by maternal attachment representation, and maternal and paternal affectionate parenting behavior. Lastly, as factors affecting self-control, they were influenced by attachment representation to parents of origin, maternal affectionate parenting behavior, and maternal independence-oriented parenting behavior. Conclusion: This research revealed that parental childhood attachment representations and parenting behavior are important variables affecting the development of self-regulation in preschoolers. This finding can be used as basic data for parent education content to help preschoolers grow healthier and happier and as basic data for a program to improve parent-child attachment.