• The Korean Journal of Physiology
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• v.4 no.2
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• pp.37-44
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• 1970

Human body volumes were calculated from the measurments of body height and body weight. Equations Suited to express the relations of height, weight, and surface area to show the body volume were derived from the body volume measurements by means of underwater. weighing method. Underwater body weights were corrected for the residual volume of long obtained by the Rahn's three breath method. Underwater weighing was performed on 173 male subjects aged between 13 and 51 years. Subjects were divided into 4 age groups, namely, 13-16 years group of 47 subjects, 16-19 years group of 46 subjects, adult group aged between 22 and 38 years comprising 45 subjects, and middle-aged group (40-51 years) of 35 subjects. The group division was made on .the basis of physical growth and development. The following results were obtained. 1. Body height (H, cm), body weight (W, kg), body surface area $S,\; m^{2})$, and body volume (V, liter.) interrelated closely. V/S showed a high correlation with W/H and the coefficient of correlation was r=0.97 irrespective of age group differences of the subjects. The coefficients of correlation between V/S and W/H in the total mate subjects as a single group was r=1.983. Subsequently the following regression equation was obtained. V = S X (54.84 W/H + 14.08) The agreement of body volume values obtained by the calculation and underwater weighing in the total subject group was better than that of the separate age group division. 2. The calculated values of body volume were: 40.4 l (euiqvalent to the body density value of 1.0562 kg/1) in 13-16 years group; 52.0 l (equivalent to density value of 1.0723 kg/l) in 16-19 years group; 55.3 l (equivalent to density value of 1.0570 kg/l) In the adult group; and 54. 0 l (equivalent to density value of 1.074 kg/l) in the middle-age group. The mean deviation of calculated from the measured volume value ranged between ${\pm}0.55$ and ${\pm}0.81$ liters. 3. The correlation between V/S and mean skinfold thickness of 4 sites (arm, back, iliac and chest) was high, namely, the coefficient of correlation was r=0.656. The coefficients of correlation between V./S and the $R\"{o}hrer$ index ranged between r=0.668 and r=0.810 affected by the difference in group age of the subject. The body volume (V) alone correlated poorly than V/S with mean skinfold thickness (r=0.606) and the $R\"{o}hrer$ index (r ranged between 0.274 and 0.588).

• Journal of Preventive Medicine and Public Health
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• v.27 no.3 s.47
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• pp.581-595
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• 1994

To investigate the effect of carbon disulfide on blood pressure, the BP measurements in the periodic health examination results and the medical records of factory clinic were reviewed. The study subjects were composed of 1336 male and 544 female workers, who were categorized into three groups by the exposure status-highly exposed, moderately exposed and non-exposed group. The results of the study were as follows; 1. The age-adjusted mean systolic and diastolic BP of male workers were 122.35 mmHg/79.11 mmHg in highly exposed, 121.57mmHg/79.05mmHg in moderately exposed and 122.67mmHg/82.27mmHg in non-exposed group. For female workers, BPs were 115.13mmHg/74.49mmHg in moderately exposed and 113.48mmHg/74.30mmHg in non-exposed group. 2. In multiple regression analysis of maximum BP against Age and tenure, the slope coefficients of age and tenure on the systolic BP were 0.379, 0.667 respectively and those on the diastolic BP were 0.331, 0.405 respectively in highly exposed male workers. Tenure was a significant variable in this study. For female workers, however the slope coefficients of tenure on BP were significant only for systolic BP of moderately-exposed group. 3. In multiple regression analysis of Bp against age, cumulative exposure index (CEI), cholesterol, all the variables showed significant slope coefficients in male, but age and CEI on systolic BP were significant for female workers (p<0.05). 4. In the multiple analysis of the amount of Bp change and the velocity of Bp change among male workers, the slope coefficients of tenure tended to increase as exposure level increased. Among female workers, the slope coefficients of tenure were significant on the amount of Bp change and the velocity of Bp change in moderately exposed group.

• Journal of Korean Academy of Nursing
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• v.8 no.2
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• pp.63-77
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• 1978

Studies pertaining to influential factors on adoption and practice of family planning are very much needed to lower fertility, for family planning has regarded as only one social acceptable means to curb the accelerated population growth. One of the influential factors is known as rumors on family planning methods that hinder the actual practice of family planning. This study generally aimed at disclosing rumors on family planning methods prevalent in rural communities so that one could gain some in sights to cope with the ill effects of rumors to promote family planning Practice in rural communities in Korea. In order to accomplish the general aims this study formulated following four specific objectives; 1. Find out types and frequencies of rumors exposed of contraceptive methods. 2. Find out the relationship between the rumors exposed and socio-economic and demographic characteristics of new village leaders and health workers. 3. Examine the relationship between family planing rumors and family planning practices. The materials for this study were drawn from the two different sets of data gathered in July and Octorber 1977 respectivily by Center for Population ＆ family Planning, Yon sei University. One is current family planning practice among eligible women reaiding in 4 Myuns in Kwang Wha country and the other is Survey on Rumor on family planning method heard by new village leaders and health workers in the four myuns. The four Myuns were divided into 60 small areas. Current family planning practice rate in each small area and as a whole were calculated. The unit of analysis in this study was not the indviduel person but the 55 small areas. Percentage, average, F-Test t-test and a coefficient of correlation were used for statistical analysis. Results of this study could be summarized as follows: 1. Rumors by different method of contraception: Medical complications, gastro-intestinal disorders, and difficulty in usage one most prevalent rumors about oral pills. Around 49% -77% of the 55 areas were often heard and the most frequent rumor was related medical complications of oral pills. Rumors on medical complications and incomplete effect of intrauterines as contraceptive were heard 51-66% of the 55 small areas. Rumors that vasectomy resulted in family problems, for instance infiedelity of spouse were often heard to 44% of the 55 small areas. 2. Rumors by socio-economic and demographic characteristic of new village leader and health workers: Among the demographic characteristics such as sex, age and sex composition of children, sex and age differentials in frequency of rumors heard more observed, Female new village health workers have heard more frequently than male new village leader. (t = 7.137, p> 0.01, d.f. = 53, a coefficient of correlation 0.27, p>0.05) The Younger age group less than 40 years of age have heard rumors of than the group over 40 years old. (t = 7.18, p>0.01, d.f. = 53, a coefficient of correlation 0.27, p>0.05) However, it was not observable that a consistent sex and age differentials in frequency of rumors heard of each contraceptive mettled, But, more female new village health works heard of rumors about intrauterine device than male new village leaders. (t = 0.497, p> 0.01, d.f. = 53, a coefficient of correlatin 0.32, p>0.01) 3. It was found that there was no statistically significant relationship between the frequency of rumors heard and current family planning practices on the whole, However, frequency of rumors heard about vasectomy appeared to have a positive relationship with current practice of vasectomy. A rather consistent pattern of relationship between“requency of rumors heard”and current family practice rate was demonstrated of 10 graphes which showed the relation between the two variagles. The current family planning practice rate in the“never heard”group and “frequently heard”group was equally lower than that in“often heard”group. The relatively consistent ∩ pattern of relationship needs to be farther investigated, for this pattern is different from the relationship that has been assumed to exist between these two variables.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.3
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• pp.302-307
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• 2010

The present study aimed to investigate the effects of maternal factors on body weight at hatching (day-old) and at six weeks of age in a commercial broiler line. A total of 6,765 records on body weight at day-old (BWTDO) and 115,421 records on body weight at six weeks of age (BWT6W), originated from a commercial broiler line during 14 generations, were used to estimate genetic parameters related to the effects of maternal traits on body weight of chicks immediately after hatch or six weeks thereafter. The data were analyzed using restricted maximum likelihood procedure (REML) and an animal model with DFREML software. Direct heritability ($h^{2}{_a}$), maternal heritability ($h^{2}{_m}$), and maternal environmental variance as the proportions of phenotypic variance ($c^{2}$) for body weight at day-old were estimated to be 0.050, 0.351, and 0.173, respectively. The respective estimated values for body weight at six weeks of age were 0.340, 0.022, and 0.030. The correlation coefficient between direct and maternal genetic effects for six-week-old body weight was found to be -0.335. Covariance components and genetic correlations were estimated using a bivariate analysis based on the best model determined by a univariate analysis. Between weights at hatching and at six week-old, the values of -0.07, 0.53 and 0.47 were found for the direct additive genetic variance, maternal additive genetic variance and permanent maternal environmental variance, respectively. The estimated correlation between direct additive genetic effect influencing weight at hatch and direct additive maternal effect affecting weight at six weeks of age was -0.21, whereas the correlation value of 0.15 was estimated between direct additive maternal effect influencing weight at hatch and direct additive genetic effect affecting weight at six-week-old. From the present findings, it can be concluded that the maternal additive genetic effect observed for weight at six weeks of age might be a factor transferred from genes influencing weight at hatch to weight at six-week-old.

• Korean Journal of Social Welfare
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• v.64 no.2
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• pp.185-212
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• 2012

This study examines changes in income inequality and income mobility associated with a transition to old age. In understanding the dynamics of income distribution over the later life course, it is important to explore the changes in income dispersion and the changes in relative income positions jointly. Data come from Korean Labor and Income Panel Study(KLIPS) 2nd, 7th, 12th wave. The results are as follows. First, a transition to old age is associated with an increase in income inequality. The Gini index of inequality increased steadily over the life course. Second, a transition to old age is associated with substantial income mobility. The Spearman's rank correlation coefficient between two periods was the lowest at the time of the transition. Increasing income dispersion and significant income mobility can be conceptualized as "income insecurity", since the older population are less likely to cope with income fluctuations. Third, in explaining such changes over time, changes in work life during old age and a subsequent decrease in earnings seem to be the most influential factor.

• Journal of the Korean Wood Science and Technology
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• v.10 no.3
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• pp.168-179
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• 1982

The first step to utilize the growing resources of Italian poplar (Populus euramericana I-476) for pulp-Woods, its characteristics and adaptabilities to the pulp industry must be investigated completely. The plantation methods are important for its fast growing in stock, and no less important is the cutting age for its utilization as pulpwood. In this paper, the stone groundwood pulping, refiner groundwood pulping and chemi-groundwood pulping characteristics by the age of tree, along with their physical and chemical characterstics were tested, and relationships between the age groups were analyzed to find out the optimum felling age. The results obtained are as follows: 1. The coefficient of pliability was a little higher in the case of younger trees. 2. The water retention value of each pulp was directly proportional to its physical strength, but this tendency was not detected between the age groups of sample woods. 3. Generally, the physical strength of younger wood pulp was lower regardless of the pulping process. But in the case of pretreatment with NaOH, Asphund and CGP pulp from 5 year old sample wood were stronger in physical strengths than those of GP and Asplund pulp with no pretreatment from 10 years old sample wood. 4. The tear factor of Asplund pulp with alkali pretreatment was higher than that of CGP pulp but the breaking length and the burst factor was similar in all processes. Considering the pulp yield and its brightness, CGP process seems to be advantageous. 5. The dissimilarity of physical strength between 7 and 10 years old wood pulp was not very large in all pulping processes but the physical strength of 5 year old wood pulp was very weak. In the of groundwood pulping from Italian poplar woods, 5 year old wood pulp should be mixed with other long fiber pulp for making a good paper.

• Korean Journal of Poultry Science
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• v.21 no.3
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• pp.175-182
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• 1994

An experiment was conducted to establish a large scale production method of anti-serum against chicken IgM and to profile the developmental changes of serum IgM levels during the feeding period(from hatching to 7 weeks of age) in broiler chicks. Blood samples were taken from Hubbard chicken at the age of hatching, three days of age, and weekly thereafter till to 7 weeks of age. The pure IgM was isolated from ammonium sulfate treated chicken serum by both sephadex G-200 and sepharose CL-6B chromatography. The breaking-through peak containing IgM appeared from the fraction 26 to 28. These fractions consisted mainly of IgM when tested by anti-chicken IgM(Nordic, Netherlands). Immunized with the heavy chain of this purified IgM, the rabbit immune sera(anti-chicken IgM) were formed a reaction only with the purified chicken IgM. The quantitative assay of serum IgM were carried by RID method. The optimal time for diffusion was 14 hours and the coefficient of determination($R^{2}$) for regression equation of standard curve was 0.992. It was observed that IgM concentrations were the highest at hatching(3.23 mg /mL), after that decreased gradually. From 2 to 5 weeks of age the levels unchanged(2.0 ~ 2.3mg /mL), and gradually decreased to 7 weeks of age(1.3 mg /mL).

• Health Policy and Management
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• v.28 no.4
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• pp.378-391
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• 2018

Background: People who were born in different years, that is, different birth cohorts, grow in varying socio-historical and dynamic contexts, which result in differences in social dispositions and physical abilities. Methods: This study used age-period-cohort analysis method to establish explanatory models on healthcare expenditure in Korea reflecting birth cohort factor using intrinsic estimator. Based on these models, we tried to investigate the effects of ageing population on future healthcare expenditure through simulation by scenarios. Results: Coefficient of cohort effect was not as high as that of age effect, but greater than that of period effect. The cohort effect can be interpreted to show 'healthy ageing' phenomenon. Healthy ageing effect shows annual average decrease of -1.74% to 1.57% in healthcare expenditure. Controlling age, period, and birth cohort effects, pure demographic effect of population ageing due to increase in life expectancy shows annual average increase of 1.61%-1.80% in healthcare expenditure. Conclusion: First, since the influence of population factor itself on healthcare expenditure increase is not as big as expected. Second, 'healthy ageing effect' suggests that there is a need of paradigm shift to prevention centered-healthcare services. Third, forecasting of health expenditure needs to reflect social change factors by considering birth cohort effect.

• Korean Journal of Exercise Nutrition
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• v.24 no.1
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• pp.9-13
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• 2020

[Purpose] This preliminary study aimed to develop a regression model to estimate the resting metabolic rate (RMR) of young and middle-aged Koreans using various easy-to-measure dependent variables. [Methods] The RMR and the dependent variables for its estimation (e.g. age, height, body mass index, fat-free mass; FFM, fat mass, % body fat, systolic blood pressure, diastolic blood pressure, mean arterial pressure, pulse pressure, and resting heart rate) were measured in 53 young (male n = 18, female n = 16) and middle-aged (male n = 5, female n = 14) healthy adults. Statistical analysis was performed to develop an RMR estimation regression model using the stepwise regression method. [Results] We confirmed that FFM and age were important variables in both the regression models based on the regression coefficients. Mean explanatory power of RMR₁ regression models estimated only by FFM was 66.7% (R²) and 66.0% (adjusted R²), while mean standard errors of estimates (SEE) was 219.85 kcal/day. Additionally, mean explanatory power of RMR₂ regression models developed by FFM and age were 70.0% (R²) and 68.8% (adjusted R²), while the mean SEE was 210.64 kcal/day. There was no significant difference between the measured RMR by the canopy method using a metabolic gas analyzer and the predicted RMR by RMR₁ and RMR₂ equations. [Conclusion] This preliminary study developed a regression model to estimate the RMR of young and middle-age healthy Koreans. The regression model was as follows: RMR₁ = 24.383 × FFM + 634.310, RMR₂ = 23.691 × FFM - 5.745 × age + 852.341.

• Journal of the Korea Concrete Institute
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• v.16 no.3 s.81
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• pp.425-431
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• 2004

This paper describes an experimental investigation of how time-dependent deformations of high strength concretes are affected by maximum size of coarse aggregate, curing time, and relatively low sustained stress level. A set of high strength concrete mixes, mainly containing two different maximum sizes of coarse aggregate, have been used to investigate drying shrinkage and creep strain of high strength concrete for 7 and 28-day moist cured cylinder specimens. Based upon one-year experimental results, drying shrinkage of high strength concrete was significantly affected by the maximum size of coarse aggregate at early age, and become gradually decreased at late age. The larger the maximum size of coarse aggregate in high strength concrete shows the lower the creep strain. The prediction equations for drying shrinkage and creep coefficient were developed on the basis of the experimental results, and compared with existing prediction models.