• Journal of Korea Foundry Society
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• v.19 no.5
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• pp.433-439
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• 1999

Rapidly solidified Mg-Al-Si base alloys containing Ca were obtained by melt spinning. The melt-spun ribbons were aged isochronally or isothermally to investigate age hardening phenomena and microstructural change according to the alloy composition. Age hardening occurred after aging at $200^{\circ}C$ for 1h mainly due to the precipitation of $Al_2Ca$ and $Mg_2Ca$, which have coherent interfaces with the matrix. With the increase of Ca content, the hardness values of the alloy ribbons were increased. Among the alloys, Mg-10Al-2 Si-3Ca alloy showed a good thermal stability at elevated temperature.

• Journal of The Korean Society of Grassland and Forage Science
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• v.11 no.2
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• pp.97-101
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• 1991

This experiment was carried out to determine the effect of pure mineral nitrogen fertilization on dry matter yield and the amounts of advisable mineral nitrogen on grassland according to its age at the "Federal Institue for Agriculture in the Alps" in Austria. The results obtained were as follows: 1. With only PK-fertilizing average dry matter yields per year were progressively declined during the period of the studies. Compared with the relatively younger grassland(1st-5th year) the DM-yields were decreased by 35% in older grassland (11th-final year). 2. Due to the less reduction of DM-yields by mineral nitrogen application according to the age of grassland. With N-fertilizing the reduction of DM-yields in relatively older grassland was less than that of younger grassland by 11-21%. 3. At 4-and 5-cut systems the nitrogen amounts for the highest marginal yield(the "most efficient" Ndressing rate) per ha and year were distinctly declined in the relatively older grassland. 4. Required efficiencies of mineral nitrogen were not influenced by the age of grassland.he age of grassland.

• Korean Journal of Health Education and Promotion
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• v.6 no.2
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• pp.58-65
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• 1989

This study analyzes the structural characteristics of rapid changes in Korean population, using the data of a census and other data on the changes in the population. Major findings are : 1. During 1950~1955, annual increase rate of population was about 1.02%, about 2.88% during 1955~1960, and 1.36% during 1980~1985. It is expected to decrease to 0.07% during 2015~2020. 2. Major Age Composition 0~14 is expected to reduce to 16.5% in 2020 from 41.2% in 1955, while the ratio of population aged 15~64 is expected to increase to 72.1% from 55.5%. Furthermore, for the population group of age 65 and over is expected to increase from a mere 3.3% to 11.4%. 3. The aging index of population is expected to increase to 69.5 in 2020 from 8.0 in 1955 and so the old dependency ratio is expected to 15.9 from 6.0 4. The median age is expected to 40.2 in 2020 from 19.0 in 1955. 5. In 2020 the child-woman ratio is expected to reduce to 22.3 from 64.7 in 1955. 6. In 2020 the age index of 0~4 is expected to 57.4 from 169.4 in 1955, and the age index of 65~69 to 261.7 from 95.6 on the contrary.

• Korean Journal of Community Nutrition
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• v.23 no.5
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• pp.424-430
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• 2018

Objectives: The purpose of this study was to compare predictions and measurements of the resting energy expenditure (REE) of overweight and obese adult women in Korea. Methods: The subjects included 65 overweight or obese adult women ranging in age from 20~60 with a recorded body mass index (BMI) of 23 or higher. Their height, weight, waist-hip ratio, and blood pressure were measured. The investigator also measured their body fat, body fat percentage, and body composition of total weight without fat using Dual energy X-ray absorptiometry (DXA) and measured resting energy expenditure by indirect calorimetry. Measured resting energy expenditures were compared with predictions from six methods: Harris-Benedict, Mifflin, Owen, WHO-WH, Henry-WH, and KDRI. Results: Harris-Benedict predictions showed the smallest differences from measured resting energy expenditure at an accurate prediction rate of 70%. The study analyzed regression between measured resting energy expenditure and body measurements including height, weight and age. The formula proposed by this research is as follows: Proposed REE equation for overweight and obese Korean women = $721-(1.5{\times}age)+(0.4{\times}height)+(9.9{\times}weight)$. Conclusions: These findings suggest that age is a significant variable when predicting resting energy expenditure in overweight and obese women. Therefore, prediction of resting energy expenditure should consider age when determining energy requirements in overweight and obese women.

• PNF and Movement
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• v.9 no.4
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• pp.23-31
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• 2011

Purpose : The aim of this study was to investigate the correlations between body compositions and bone mineral density in young women and postmenopausal women with low bone mineral density. Methods : Eleven young women (age, $25.85{\pm}1.96yrs$; height, $160.28{\pm}2.16cm$; weight, $56.89{\pm}9.66kg$) and ten postmenopausal women (age, $25.85{\pm}1.96yrs$; height, $160.28{\pm}2.16cm$; weight, $56.89{\pm}9.66kg$) with low bone density on femur neck were participated in this study. All subjects performed the measure of body composition and BMD on lumbar body and femur neck. Results : The results were as follows. Percent body fat, waist-hip ratio and body mass index(BMI) were significantly increased in postmenopausal women. BMD in lumbar body and femur neck were significantly decreased in postmenopausal women. There were negative strong correlation between BMD of the femur and age in young women. There were negative strong correlation between BMD of the femur and age or the years of menopause in postmenopausal women. There were positive strong correlation between BMD of the femur and BMD of lumbar body. Conclusion : Percent body fat and BMI were more increased in young women than in postmenopausal women. And there were negative strong correlation between BMD and age or the years of menopause in postmenopausal women.

• Journal of the Korean earth science society
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• v.22 no.1
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• pp.1-9
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• 2001

Composition of the major and trace elements, Rb-Sr isochron age Sr-Nd isotope composition were determined for foliated in the Jeonju area, in the middle part of the Ogcheon Fold Bet, Korea. The geochemical characteristics of the Jeonju foliated granite indicate that the granite had been crystallized from a calc-alkaline series, and formed in a volcanic are environment. The isotopic compositions of the Jeonju foliated granite give Rb-Sr whole rock errorchron age of 168.2${\pm}$8 Ma(2${\sigma}$), corresponding to the middle Jurassic period, with the Sr initial ratio of 0.71354${\pm}$0.00031. $^{143}$Nd/$^{144}$Nd ratios, ${\varepsilon}$Nd and ${\varepsilon}$Sr values range from 0.511477 to 0.511744, -15.4${\sim}$-21.2, and +108.8${\sim}$+l42.6, respectively. Model ages were caculated to be 1.82${\sim}$2.89Ga. The isotopic data of Jeonju foliated granite indicate that the source material may have been derived from partial melting of continental crust materials.

• Korean Journal of Community Nutrition
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• v.13 no.4
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• pp.489-498
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• 2008

This study was carried out to identify bone mineral density(BMD), body composition, lifestyle and dietary habits of young women by physical measurement and questionnaires. The study subjects, 190 young women living in Seoul, were divided into three age groups: $20{\sim}24$ years(93), $25{\sim}29$ years(44) and $30{\sim}39$ years(53). There was no significant difference in mean body muscle mass, protein, mineral, body fat and BMI among the three age groups. The rate of low weight(18%) in 20 years group was higher that of the 30 years(11.3%). The mean BMD and T-score were $0.44g/cm^2$ and -0.66. BMD and T-score of the forearm bone were significantly higher in the $30{\sim}39$ years group. But BMD and T-score of calcanues were not significantly different among the three age groups. The rate of normal, osteopenia and osteoporosis subjects by BMD were 60.5%, 38.4%, 1.1%, respectively. The rate of osteopenia in $20{\sim}24$ years group was significantly higher than the other age groups. The rate of meal irregularity was significantly higher in $20{\sim}24$ years group. The rate of women who walk and are exposed to sunlight more than 1hr per day were significantly higher in $20{\sim}24$ years group than the others. However, the score of food behaviors is significantly higher(bad) in $20{\sim}24$ years group than the others. The relationship between BMD and frequency of food intake showed significant differences in beans, broom, seaweed and rice wine. In conclusion, the risk rate of BMD was very high, 40% of the subjects, and the risk rate of BMD was higher in 20 years group than 30 years group, and the rate of low weight in 20 years group was higher than in 30 years group. The food habits and behaviors were not healthy enough. Therefore, nutrition education is needed for bone health.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.6
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• pp.848-856
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• 2004

Black Bengal goat is primarily reared for meat, skin comes here as a by-product. The present trial describes the effect of age on different carcass characteristics of Black Bengal goats of either sex. A total of 61 Black Bengal goats of different age and sex groups were slaughtered. They were reared under semi-intensive management on milk alone or with concentrates (of 10.14 MJ ME and 10.48 g M/kg DM) and freshly cut Napier grass (2 MJ ME and 25 g CP/kg of fresh matter) that provides the estimated NRC (1981) requirement. The four age groups were: pre-weaned kids (0-90 day), post-weaned kids (91-180 days), growing (181-365 days) and adult (>365 days). Goats were slaughtered according to 'Halal' method by severing the major vessels of the throat by a transverse cut. Different slaughter parameters of Black Bengal goat can be best predicted from the equations as follows: live weight (kg)=0.801 (shoulder height (cm))-24.32, ($r^{2}$=0.94); carcass weight (kg)=0.364 (height at hind legs (cm))-11.54, ($r^{2}$=0.91); edible weight (kg)=0.623 (shoulder height (cm))-19.94, ($r^{2}$=0.91) and saleable weight (kg)=0.701 (shoulder height (cm))-21.99, ($r^{2}$=0.92). Live weight, carcass weight, edible weight and saleable weight of castrated goat at one-year onward ranges from 20-22, 9.4-10.5, 14-16 and 16.6-18.8 kg, respectively, which are about 80% higher than most of the reported observations on Black Bengal goat of same age and sex. Slaughter weight, warm carcass weight, edible weight and saleable weight increased curvilinearly with age of slaughter but not affected (p>0.05) by sex. However, linearity of the response curve of affect of age on mentioned parameters ends at around 9 months. Visceral fat as per cent of live weight increased curvilinearly with age and attain its maximum (about 6%) at about 500 days. However, linear part of the quadratic model ends at about 300 days when visceral fat content is about 4.8% of body weight. Blood and skin yield for one-year old male goat was 797 g and 1.61 kg, respectively. Absolute yield of blood and skin increased curvilinealry and attained maximum level at about 400 days (13.3 months). Average proportion of different carcass cut were - round 27%, rump 7%, loin 10%, ribs (6-12th) 14%, shoulder 21%, Neck 7%, chest 14%. Thigh and shoulder constituted about 48.3% of the cold carcass weight. Overall crude protein content of meat samples of different carcass cuts progressively decreased with age starting from 57 at 0-90 days to 58, 47 and 33 per cent, respectively at 91-180, 181-365 and >365 days, respectively. Overall meat fat content increased almost linearly from 11.1% during 91-180 days to 22.9 and 39.5% during 181-365 and >365days, respectively. Results from this trial suggest that both carcass yield and carcass composition changes with age; and sex have little or no effect on carcass yield and carcass composition. However, caution should be made in using second conclusion as there were few female animals slaughtered relative to the male. Optimum slaughter age for Black Bengal goat reared under semi-intensive management with adequate feeding and management would be about 9 months when their live weight, warm carcass weight, edible and saleable weight of carcass can be about 16.74, 7.28, 12.05 and 13.81 kg, respectively.

• Korean Journal of Child Studies
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• v.26 no.6
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• pp.217-236
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• 2005

The purpose of this study was to investigate whether preschoolers' peer interaction type and level differ depending on pair compositon and task type. Preschoolers' peer interaction type and level were compared among three kinds of pair compositions(with a Younger peer, with a same-age peer, and with an older peer) as well as between two types of tasks(tasks involving real objects, and tasks involving pictures). Subjects were seventy-eight four-year-old children recruited from six child-care centers in Seoul and Gyeonggi Province. The preschoolers were randomly assigned to one of the three kinds of pair compositions. Interaction processes of the pairs were recorded by a video camera, and the scenes were transcribed for content analyses. The traniscribed peer interactions were coded according to the categories that the researcher had generated. Statistical methods used for the data analysis were frequencies, percentiles, means, standard deviations, repeated measures ANOVA, paired t-tests, one-way ANOVA. Major findings of this study were as follows: There were significant differences preschoolers' in interaction type depending on the pair compositions and the types of tasks. The preschoolers paired with the older peer used abstract collaborative explanations more frequently than in two other types of pair composition. The preschoolers paired with the younger peer used explanations without collaboration and parallel behaviors more frequently than in two other types of pair composition.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2003.11a
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• pp.101-102
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• 2003

This experiment was conducted to investigate the effect of restricted feeding to pullet on growth pattern and body composition. Conventional diets(C) was formulated by NRC recommendation, and one of restricted diet started from seven to seventeen week of age(T1), and another started from twelve to seventeen(T2) with adjusted eighty percentage amount of conventional diet. Body weight decreased with starting restriction of feeding comparing to the C(P＜0.05), but reached to similar weight in all treatments at twenty week regardless restriction. All of birds started to lay egg around 1,400 to 1,450gram of body weight though the age was in order of C, T2 and T1. Fat contents of restricted group in the body were less than that of C around one thousand gram of body weight. And the tendency of body fat was similar to the first egg. After twenty week, all content of body composition were similar in all treatments. The proportion of intestinal organ weight was higher in T1 than others during restriction.