• Journal of Industrial Technology
• /
• v.23 no.A
• /
• pp.165-173
• /
• 2003

The purpose of this paper is to analysis of initial behavior of concrete pavement with initial measurement strain gauge for concrete pavement at field, and to investigate the field test results for field applicability testing. The early-age behaviors of concrete pavement slabs were measured using the strain gauges. From the slab depths and positions, the outputs from each gauges were recorded at initial curing period. The initial measurement of concrete pavement and check of crack at the joint were performed, the results could be summarized as follows. From the results of concrete strength, compressive strength and flexural strength were showed $271kgf/cm^2$, $43kgf/cm^2$ respectively. From the tests of early-age strain measurement, it was found that the strain varied at the maximum value of $150{\mu}{\varepsilon}$ and early behavior of concrete slab was showed a tensile strain. However, for long-term was showed a compressive strain due to dry-shrinkage.

• Mood & Emotion
• /
• v.10 no.1
• /
• pp.31-36
• /
• 2012

Objectives : The aim of this study was to investigate the relationship between depressive symptom, spiritual well-being and state hope in early adults and middle aged patients with depression. Methods : A total of 180 outpatient were surveyed with Beck Depression Inventory (BDI), Functional Assessment of Chronic Illness Therapy-Spiritual Well-being Scale (FACIT-Sp) and The State Hope Scale (SHS). Mean scores of BDI, FACIT-Sp and SHS were compared between two groups of different age. Correlation analysis and multiple linear regression analyses were performed to identify the effect of BDI and FACIT on SHS according to age. Results : Mean scores of SHS and FACIT were higher significantly in middle aged group than early adults group, while BDI was not different between two groups. And early adults and middle aged patient's state hope showed a significantly negative correlation with spiritual well-being. In regression analysis, the effect of BDI, FACIT on SHS were significant in both groups and the regression model explained 42% of the variance of state hope in early adults group and 26% in middle aged group, respectively. Conclusion : These findings suggest that in depressive symptom and low state hope relationship, spirituality is important protective factor in both aged adult outpatients with depression.

• Journal of dental hygiene science
• /
• v.17 no.3
• /
• pp.250-256
• /
• 2017

The purpose of this study was to examine the influence of maternal socioeconomic status, maternal oral health behaviors, and oral health behaviors of children, on the prevalence of early childhood caries in children aged 5 years. The Korean National Health and Nutrition Examination Survey data collected between 2007 and 2014 were applied to this study, and the study sample included 824 children who received oral examinations and participated in the health behavior survey. The factor that affected the prevalence of early childhood caries were confirmed by maternal and child factors. The data were analyzed using multiple linear regression. The mothers' age, income level, and job status affected the prevalence of early childhood caries. There was a significant difference in the analysis considering the factors of motherhood and children in the prevalence of early childhood caries according to mother's age, education level, income level, and the child's oral examination. The prevalence of early childhood caries was higher in children who received oral examinations than in those who did not. When the mother's educational level was higher than college education, it was found that the index of child, i.e., there was a difference in the prevalence of early childhood caries according to the mother's educational and income levels. These results indicate that maternal socioeconomic characteristics are correlated with the oral health of children. Therefore, oral health education programs that include mothers for the prevention of early dental caries in children may improve the dental health of children. In addition, specific oral health policies are necessary to address the differences in the oral health between the income groups.

• Journal of the Korean Home Economics Association
• /
• v.41 no.11
• /
• pp.95-111
• /
• 2003

The purpose of this study was to investigate the current trend of early education and to examine the relationship between the state of early education and maternal beliefs, stress, and achievement pressure. The subjects were 275 mothers of 4∼6 year-old children in Seoul. The main results were as follows : 1) Most of the subjects' children(87.6%) were involved in early education, especially in the form of home-visit study and study papers. 2) Parental beliefs (about child development and early education) and maternal achievement pressure were significantly related to the degree of actual involvement and perceived necessity of early education. 3) Parental stress regarding child's temperament was significantly related to the starting age of early education. But the other factors of parental stress had no significant relation to the state of early education.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2013.11a
• /
• pp.48-49
• /
• 2013

This test investigates early strength and durability of concrete using early strength type materials(cement, Polycarboxylate acid). The goal of this test is to secure the strength of 5.0 MPa in 12 hours early age and strength of 14 MPa for 24 hours correspondingly. This type of admixtures, concrete curing temperature, amount of binder and other concrete properties were confirmed by experimental factors. Comparing outcomes from two cases on using early strength type materials and common materials resulted in reducing of costs and shortening of the construction period, that determined the economical benefits of using early strength materials in construction.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
• /
• v.18 no.1
• /
• pp.31-37
• /
• 2007

Objectives : A voxel based investigation of cerebral blood flow was conducted to identify functional differences during resting state between children with early-onset schizophrenia and normal controls. Methods : 19 children and adolescents with early-onset schizophrenia(8 boys and 11 girls, mean age $14.0{\pm}1.7$ years old) and 17 comparison children(13 boys and 4 girls, mean age $11.0{\pm}1.9$ years old) were examined by HMPAO-SPECT. The SPECT images were compared using statistical parametric mapping analyses, controlling for age and sex. Results : Increased cerebral blood flow in left medial and inferior frontal gyrus, right superior and middle frontal gyrus, both inferior temporal gyrus, and right cerebellar tonsil was found in children and adolescents with early-onset schizophrenia compared to control subjects. In addition, decreased cerebral blood flow in right thalamus, left posterior cingulate gyrus, right anterior cingulate gyrus and relatively wide areas from left medical frontal gyrus to superior parietal lobule were found in children and adolescents with early-onset schizophrenia compared to control subjects. Conclusion : The results of the current study provide additional evidences for brain areas involving the onset of schizophrenia in early age.

• International Journal of Highway Engineering
• /
• v.11 no.2
• /
• pp.185-194
• /
• 2009

The autogenous shrinkage of high-performance concrete, including very-early strength latex-modified concrete(VES-LMC), is generally bigger than that of normal strength concrete because of the low water/cement ratio, high binder contents, and usage of superplasticizer. Mix. proportion of VES-LMC has low water/cement ratio(0.38), high cement content(390kg/m$^3$), and aid of latex(15% of cement weight). Thus, these factors of VES-LMC, rapid water self-dissipation and evaporation within 3 hours of concrete placement would increase the autogenous shrinkage. The purpose of this study was to evaluate the early-age shrinkage, thermal deformation and autogenous shrinkages of VES-LMC with retarder contents(retarder solids-cement ratio, by weight) using to secure working time in field. The experimental results showed that retarder contents do not affect of the maximum hydration temperature. Early-age expansion of VES-LMC was mostly caused by thermal expansion and partly by autogenous expansion. The autogenous shrinkage is decreased by increasing the retarder contents within this study. On the other hand, the usage of retarder should be decided carefully considering the field conditions because an excessive usage of retarder can cause handful early-age expansion.

• The Journal of the Korea Contents Association
• /
• v.16 no.3
• /
• pp.319-327
• /
• 2016

The objective of this study is to identify the secular trend in age at menarche and to investigate the factors influence the early menarche(<12 years old) among Korean middle and high school girls. We analyzed data from the Korean Youth Risk Behavior Web-based Survey(KYRBWS) 2006-2014. This study was a descriptive study of 216,917 Korean middle and high school girls born between 1988 and 2002. Linear trends test performed to assess the trend age at menarche and percentage of early menarche. Multiple logistic regression analysis was to assess the risk factors influence the early menarche. Mean age at menarche decreased from $12.61{\pm}1.32$ years for middle and high school girls born 1988 to $11.88{\pm}0.75$ years for those born 2002(p for trends<.001). Percentage of early menarche increased from 19.7% to 25.2% between 1988 and 2002(p for trends<.001). Living in city, higher stress level, short sleep duration, and higher body mass index were associated with an early menarche among middle and high school girls(all p<.001). We found that age at menarche is still falling in the Korean adolescents, and it need intervention strategies to control the early menarche.

• Animal Bioscience
• /
• v.34 no.5
• /
• pp.886-894
• /
• 2021

Objective: An experiment was conducted to study the effect of graded concentration of digestible lysine (dLys) on performance of layers fed diets containing sub-optimal level of protein. Methods: Five diets were formulated to contain graded concentrations of dLys (0.700%, 0.665%, 0.630%, 0.593%, and 0.563%), but similar levels of crude protein (15% CP), energy (10.25 MJ ME/kg) and other nutrients. A total of 3,520 hens (26 wk of age) with mean body weight of 1,215+12.65 g were randomly divided into 40 replicate groups of 88 birds in each and housed in an open sided colony cage house. Each diet was offered ad libitum to eight replicates from 27 to 74 wk of age. The performance was compiled at every 28 d and the data for each parameter were grouped into three phases, that is early laying phase (27 to 38 wk), mid laying phase (39 to 58 wk), and late laying phase (59 to 74 wk of age) for statistical analysis. Results: Egg production, egg mass and feed efficiency (feed required to produce an egg) were significantly improved by the dLys level during the early and mid laying phases but not during the late phase. Whereas feed intake was significantly reduced by dLys concentration during mid and late laying phases but not during early laying phase. The egg weight was not affected by dLys concentration in any of the three phases. Conclusion: Based on best fitted statistical models, dietary requirements of dLys worked out to be 0.685%, 0.640%, and 0.586% during early phase, mid phase, and late egg laying phase, respectively. The calculated requirement of dLys for the respective production phases are 727 mg/b/d during the early and mid laying phases and 684 mg/b/d during the late laying phase in diets containing 15% CP.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.26 no.6
• /
• pp.112-119
• /
• 2022

Recently, as carbon neutrality has been important factor in the construction industry, many studies have been conducted on the high-volume fly ash concrete. High volume fly ash concrete(HVFC) is usually made by replacing more than 50% of cement with fly ash. However, HVFC has a disadvantage of low compressive strength in early age. To overcome this shortcoming of HVFC, improve this, interest in techonolgy using nanomaterials is increasing. Nano silica is expected to improve the early age strength of HVFC as a pozzolanic material. This study investigated the effect of nano silica on the early hydration reaction and microstructure of HVFC. The early hydration reaction of HFVC was analyzed through setting time, isothermal calorimeter, compressive strength and thermal weight analysis. In addition, the microstructure of HVFC was measured by mercury intrusion porosimetry. From the test results, it was confirmed that nano silica increased the early age strength and improve the microstructure of HVFC.