• Asian-Australasian Journal of Animal Sciences
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• v.20 no.1
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• pp.19-24
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• 2007

Covariance components and genetic parameters of weekly live body weight from hatching to six weeks of age and age of sexual maturation were estimated in a laying type Japanese quail line. The univariate and bivariate animal model analysis included hatching group and sex as fixed effects. Each trait was analysed with animal as random effect to fit the additive direct effect. Additional random effects incorporated in the models were changed according to the trait examined. The best model for a trait was chosen based on a likelihood ratio test, comparing the models with and without maternal additive genetic and maternal permanent environmental effects. Heritability estimates of live-weight at hatch and one to six weeks of age with their standard errors were 0.22${\pm}$0.088, 0.39${\pm}$0.099, 0.31${\pm}$0.086, 0.38${\pm}$0.056, 0.46${\pm}$0.055, 0.50${\pm}$0.059, and 0.56${\pm}$0.062, respectively. Direct heritability value of age of sexual maturation was moderate (0.24${\pm}$0.055). The variances due to permanent environmental effect of dam after one week of age and maternal genetic effect after two weeks of age were not important sources of variation. The correlations between direct and maternal genetic effects were negative and ranged from high to moderate values (-0.21 to -0.83). Among the weekly live weights, genetic correlations were generally high between not only successive but also early and late weightings. It suggests that selection for final weight may be based on early weight records. Genetic correlations between age of sexual maturation and live weights were low, favourable but had high standard errors. These results indicate that selection for high weight will potentially result in lower age of sexual maturation only with accurate determination of breeding values.

• Korean Journal of Veterinary Research
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• v.14 no.1
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• pp.1-7
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• 1974

Little work has been done on the changes in the blood picture occurring at different ages in cattle. In our country Kim (1963) and Jeong (1965) recorded the blood picture of mature Korean native cattle and, recently, Mun et al. (1974) has recorded the blood picture of Holstein cows. And a comprehensive survey of the blood picture of Korean native cattle has not been made. The object of the present investigation was to make good this deficiency, and to suggest standards for the blood picture of Korean native cattle at frequent intervals from birth to maturity. The cattle were kept under average farming conditions in this country. Observations were made at the following ages: at birth; 1, 2 and 4 days; 1, 2 and 4 weeks; 2,4,6 and 9 months; 1, 2 and 3 years of age. Blood samples were drawn from the jugular vein. Erythrocyte enumerations, concentration of hemoglobin in blood and hematocrit values were made in usual manner. Erythrocyte counts increased from $8{\times}10^6/mm^3$ during the first week to a level of $10{\times}10^6/mm^3$ at 2 months of age, showing steady state untill 6 months of age; it then fell to adult level ($8{\times}10^6/mm^3$) at 9 months of age. Concentration of hemoglobin in blood and hematocrit values were closely related to the changes of erythrocyte counts. The values increased from 10 g/100 ml and 31~35 ml/100 ml during the early life to 11 g/100 ml and 38 ml/100 ml at 2 months of age, showing steady state untill 6 months of age; these then fell to adult level (10 g/100 ml and 31~34 ml/100 ml) at 9 months of age for concentration of hemoglobin in blood and hematocrit values, respectively. Mean corpuscular volume and mean corpuscular hemoglobin showed a common pattern. The values were $42{\sim}43{\mu}m^3$ and 12.4 pg during the early life and fell a little to 6~9 months of age; these then increased to reach adult levels of $43{\mu}m^3$ and 12.6 pg for mean corpuscular volume and mean corpuscular hemoglobin, respectively. Mean corpuscular hemoglobin concentration was little affected with age.

• Journal of the korean academy of Pediatric Dentistry
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• v.47 no.4
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• pp.359-367
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• 2020

The aim of this study was to identify the association between candidiasis and early childhood caries and to investigate whether the experience of candidiasis or oral candidiasis before age 1 can be considered as a risk factor for early childhood caries. The database used in this study was provided by Health Insurance Review and Assessment Service. Medical records of children born from January 2010 to December 2012 were obtained, and those without dental records were excluded. Subjects were divided into several groups based on the experience of candidiasis or oral candidiasis before age 6: candidiasis group and non-candidiasis group; oral candidiasis group and non-oral candidiasis group. Another categorization was done according to the experience of candidiasis or oral candidiasis before age 1. The incidence rate of early childhood caries in each group were compared. The prevalence of dental caries in children who have been diagnosed with candidiasis or oral candidiasis before age 6 was significantly different from those who have not experienced candidiasis. Similarly, children who have suffered from candidiasis or oral candidiasis before age 1 had significantly different incidence of caries from the children without candidiasis experience.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.1
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• pp.1-10
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• 2018

It is difficult to predict the early-age cracks of strain restrained concrete members due to environmentally sensitive parameters. A new method is proposed to predict the cracks by test of autogenous deformation and self-induced restrained stress of specimens which simulates early-age crack state by hydration heat of the'Wall-On-Foundation'members. For this purpose, thermal analysis of entire structure considering the environmental condition is performed at first, and the specimens are set up where hydration heat was electronically controlled according to the analysis results. By measuring free deformation and force to compensate the autogenous strain including relaxation, feasibility of cracks can be estimated. The proposed method can predict the occurrence of cracks better than the material test of the early age concrete which has large variance. The method of this study is particularly useful when it is used as a preliminary experiments to predict the crack more precisely before full-scale concrete placement in construction of large structures.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.2
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• pp.154-160
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• 2018

Cement industries are considered key industries for reducing carbon emissions, and efforts are off the ground to reduce the use of cement in the concrete sector. As a part of this effort, research is off the ground to utilize a large amount of industrial by-products that can be used as a substitute for a part of cement. Concrete using industrial by-products has advantages such as durability, environment friendliness and economical efficiency, but there are problems such as retarding and early-age strength deterioration. Therefore, this study aimed to reduce the use of cement and solve the problem of early-age strength deterioration while using fly ash, which is an industrial by-product. Accordingly, it was confirmed that the strength was improved at all ages irrespective of curing temperature by accelerating the hydration reaction by using high fineness cement. Subsequently, high fineness cement was partially replaced with fly ash and the strength development characteristics were examined. As a result, it was possible to exhibit strength equal to or higher than ordinary portland cement even at the early age. Also, it was confirmed that even when the fly ash is replaced by 30%, it is possible to shorten the time for dismantling the forms of vertical and horizontal members.

• Journal of Chest Surgery
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• v.25 no.11
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• pp.1318-1326
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• 1992

Backgroud. To determine the influence of age at operation upon surgical outcome in patients with isolated secundum atrial septal defect, retrospective clinical analysis was done. Material and method. From June, 1976 to December, 1991, 146 patients, 63 male and 83 female patients ranging in age from 13 months to 56 years, were operated on for isolated secundum atrial septal defect. The patients were divided into 3 groups according to their age at operation: Group I [<20 years old], 91 patients[62.3%]; Group II [21 to 40 years old], 44 patients[30.1%]; GroupIII[>41 years old], 11 patients[7.6%]. Significant differences in clinical features, hemodynamic function, early and late results between age groups were speculated. Results. One hundred thirty-one patients[89.6%] were symptomatic at the time of operation, the most common symptoms being dyspnea on exertion, recurrent respiratory infection, palpitation and chest pain. Patients in NYHA class III or IV were 3.3% in group I, 25% in groupIII, and 54.5% in group Ill. Hemodynamic data was available for 138 patients [94.5%]. Significant pulmonary hypertension [MPA systolic pressure $^3$ 40mmHg] was noted in 22 patients [15.9%]. Patients with pulmonary vascular disease [Rp/Rs>1.25] were 2% in group I, 7.3% in group Il, and 9.1% in groupIII. But there were no significant differences between the age groups in the size of the shunt or the ratio of pulmonary to systemic flow. Atrial septal defects were closed with direct suture in 144 patients and patch repair was performed in 2 patients with high defect. Atrial arrhythmia [8.2%] was the most common postoperative complication. The mean [LSD] duration of follow-up in all patients was 16$\pm$22 months [range, 1~96 months]. Functional result was excellent regardless of the age groups. During follow-up period, late cardiovascular events were arrhythmia [7 cases], reoperation for recurrent ASD [2 cases], and premature late death due to bacterial endocarditis [1 case]. Incidence of preoperative and late atrial fibrillation was significantly higher in older age group. Conclusion. Age at operation is one of the most important predictor of early and late surgical outcome with its impact on the following factors : 1] hemodynamic alterations and ventricular dysfunction due to longstanding volume and pressure overload, 2] pulmonary vascular disease, and 3] atrial arrhythmia including atrial fibrillation as a result of atrial dilatation. Therefore, among patients with surgically repaired atrial septal defects, those operated on over the age of 20 require careful supervision on the long-term basis.

• Journal of Animal Science and Technology
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• v.53 no.5
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• pp.497-502
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• 2011

The present survey was conducted to provide basic information on Hanwoo calf weaning age and farmer's understanding of early weaning. Eight hundred and sixty-two Hanwoo breeding farms from all nine provinces were surveyed via personal interviews. The percentages of farms categorized by herd size were 30.5%, 32.8%, 26.0% and 10.7% for <50 heads, 51~100 heads, 101~200 heads and >200 heads, respectively. The percentage of farms weaning calves at three months of age were 39.2% and 12% of farms weaned calves less than two months of age. But the percentage of farms weaning at or over four months of age were still high, being 16.1% at four months of age and 16.6% over five months of age, respectively. The result of the present study showed that calf weaning age in Hanwoo was inconsistent and higher percentage of farms wean calves at three months of age among the surveyed farms. The improvement of cow reproductive performance was answered as the biggest merit of early weaning.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.16 no.2
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• pp.219-230
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• 2005

Objectives : This study was designed to compare the demographic data, clinical characteristics, developmental delay, and psychological tests between childhood-onset and adolescent-onset schizophrenic in-patients. Methods Medical records of the 17 childhood-onset (very early onset) Schizophrenia and 16 adolescent-onset (early onset) Schizophrenia in-patients were reviewed. Sex, age, psychiatric past history, prodromal symptoms and period, subtype, co-morbid disease, developmental delay, prescribed drug and dosage, treatment response, intelligence quotient (IQ), and Rorschach test were evaluated. Results : The mean admission age of childhood-onset (very early onset) group and adolescent-onset (early onset) group were 12.69$({\pm}2.34)$ and 15.13$({\pm}1.04)$ years. The mean onset age of childhood-onset(very early onset) group and adolescent-onset (early onset) group were 10.79$({\pm}1.95)$ and 14.46$({\pm}0.82)$ years. The mean prodromal period of childhood-onset (very early onset) group and adolescent-onset (early onset) group were 15.94$({\pm}12.33)$ and 8.06$({\pm}6.10)$ month. The time to remission period of childhood-onset (very early onset) group and adolescent-onset (early onset) group were 50.58$({\pm}24.67)$ and 30.06$({\pm}18.04)$ days. Longer time to remission period in childhood-osnet (very early onset) group was associated with earlier age of onset. The mean of total IQ, performance IQ, verbal IQ were at an average level. Discussion : Childhood-onset (very early onset) group and adolescent-onset (early onset) group Schizophrenia had different clinical and psychological features including prodromal period, and IQ subtests.

• Korean Journal of Heritage: History & Science
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• v.53 no.4
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• pp.216-233
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• 2020

This study set out to review tomb culture in the Gyeongju region during the Bronze Age, and also examine the patterns of dolmens during their end phase. For these purposes, the study analyzed 18 tomb relics from the Bronze Age and nine from the early Iron Age. Gyeongju belongs to the Geomdan-ri cultural zone. Approximately 120 tombs from the Bronze Age have been excavated in the Gyeongju region. There are fewer tombs than dwellings in the region, which is a general characteristic of the Geomdan-ri cultural zone. Although the number of tombs is small, the detailed structure of the dead body is varied. During the Bronze Age, tombs in the Gyeongju region were characterized by more prolific construction of pit tombs, dolmens with boundaries, and stacked stone altars than were the cases in other areas. There is a great possibility that the pit tombs in the Gyeongju region were influenced by their counterparts in the northeastern parts of North Korea, given the spindle whorl artifacts buried at the Dongsan-ri sites. Dolmens with boundaries and stacked stone altars are usually distributed in the Songguk-ri cultural zone, and it is peculiar that instances of these are found in large numbers in the Gyeongju region as part of the Geomdanri cultural zone. Even in the early Iron Age, the building of dolmens with boundaries and stacked stone altars continued in the Gyeongju region under the influence of the Bronze Age. A new group of people moved into the area, and they crafted ring-rimmed pottery and built wooden coffin tombs. In the early Iron Age, new rituals performed in high places also appeared, and were likely to provide venues for memorial services for heavenly gods in town-center areas. The Hwacheon-ri Mt. 251-1 relic and the Jukdong-ri relic are ruins that exhibit the aspect of rituals performed in high places well. In these rituals performed in high places, a stacked stone altar was built with the same form as the dolmens with boundaries, and a similar rock to the cover stone of a dolmen was used. People continued to build and use dolmens with boundaries and stacked stone altars while sustaining the Bronze Age traditions, even into the early Iron Age, because the authority of dolmens was maintained. Some dolmens with boundaries and stacked stone altars, known as being Bronze Age in origin, would have continued to be used in ritual practices until the early Iron Age. Entering the latter half of the second century B.C., wooden coffin tombs began to propagate. This was the time when the southern provinces, including the Gyeongju region, were included in the East Asian network, with the spread of ironware culture and the arrival of artifacts from central China. Around this time, dolmen culture faded into history with a new era beginning in its place.

• Korean Journal of Human Ecology
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• v.14 no.3
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• pp.387-399
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• 2005

The purpose of this study is to investigate the differences of early childhood teachers' job satisfaction and burnout by variables and to analyze the relationship between the two subject matters. Then this study will serve to improve overall quality of early childhood education through fair comprehension about them. We surveyed 333 teachers in total, 171 public/private kindergarten teachers and 162 preschool teachers. A questionnaire by ECJSS of Jord-Bloom(1989) and Fleischer(1985) was used to measure the degree of job satisfaction, along with the version MBI(Maslach Burnout Inventory) by Maslach and Jackson(1981), adjusted by An, youngkil(I992) and Seo, jiyoung(2002), to check the degree of burnout. It was found that job satisfaction was higher among the surveyees of old age or with more education/less working hours. Small salaries, however, was one of the causes of low job satisfaction. Emotional burnout was shown in the surveyees of old age or with good education/career records. On the other hand, exhaustion from a lack of accomplishment was shown in single, young and low paid teachers. Thus, burnout and job satisfaction had a highly negative coefficient of correlation, meaning that job satisfaction gets high when burnout gets low.