• The Korean Journal of Applied Statistics
• /
• v.22 no.2
• /
• pp.365-373
• /
• 2009

Since 1990, identifying the sex of fetus and illegal abortion has brought the sex ratio imbalance at birth in Korea due to a notion of preferring a son to a daughter, socio-economic development, population policy, and so forth. Although there have been many researches such as time series analysis and region difference analysis to monitor this sex ratio imbalance, they have a defect that time and space could not be included in the analysis simultaneously. This study analyzes the sex ratio imbalance at birth, taking into account time and region at the same time. The analysis considered the numbers of male and female babies, who were born as the third or latter in their families, in 2000 and 2001 at 234 Gu / Si / Goon administrative districts. Here, we suggest a mixture model of binomial distributions, assuming heterogeneous populations. The estimation of the location parameters, weights and correlation coefficient of the mixture model is conducted by the EM algorithm, and the heterogeneity of the regions is expressed as a picture using ArcView GIS.

• Proceedings of KHEA Conference
• /
• 1997.07a
• /
• pp.127-127
• /
• 1997

• Korea journal of population studies
• /
• v.19 no.2
• /
• pp.5-18
• /
• 1996

• Korea journal of population studies
• /
• v.16 no.2
• /
• pp.1-23
• /
• 1993

Korea fertility level has dropped since the 1960's and speed of decline has accelerated in the 1980's. In the resuls, the growth rate reached to less then 1 percent in 1990 and will be $\ulcorner$0 $\lrcorner$ percent growth in 2021. The total population will increase to 50, 586 thousand persons in 2021 then will decrease. With the rapid fertility decline the age structure of Korean population has changed : while the proportion of child population aged 0-14 is decreasing sharply, that of old-age population aged 65 and over is increasing. Because of the recent increase of sex ratio at birth, the sex structure among the young generation has been destorted; the sex ratio at age 0-4 was as high as high as 112.0 in 1990. The effects of these population phenomena on Korean society are the followings: 1) Old age dependency ratio is increasing rapidly and continuously and will be about 40.0 from the 2050's. 2) Because of the rapid decline of the number of births, the absolute number of the major labour force at age 25-34 will decrease after around 2000 and then from the 2010's become less than that in 1990. 3) Since the large fertility defferentials by womens's educational level have continued and the relation between the educational levels of mothers and children are very strong, level has dropped among higher educated women first when the average fertility level has declined in Korea, the average educational level of the children is may be expected to be relatively low and then the future productivity is will be also low, which causes the decline of 'quality of population. 4) When the high sex ratio at birth (over 110 since 1986) continues, number of brides will be short by over 20 percent from the 2010s, which will bring various kinds of social prblems. Therefore, the counter measures in concrete to relieve the heavy problems are recommended as follows: 1) The extention of the birth intervals, which helps to drop the population growth rate at the same level of number of children per women. 2) The positive supports for out-migrants, which helps to reduce the population size without any destortion of age-sex structure. 3) The defferent supports of family planning for the higher and lower classes, which helps to reduce the gaps between different ferility levels of the classes and to keep and improve the quality of population. 4)population education for both students and adults, which helps to minimize the gap between the private and public requirements.

• The Korean Journal of Health Service Management
• /
• v.8 no.3
• /
• pp.137-145
• /
• 2014

The objective of this study was to analyze the risk of preterm birth (PTB) and low birth weight (LBW) in extramarital birth by analyzing 2008-2012 birth certificated data (2,328,719 births) from Korea Statistics. Odds ratio and 95% confidence intervals (95% CI) were calculated from logistic regression analyses to describe the associations between PTB & LBW and extramarital birth adjusted for maternal age, maternal occupation & education, infantile sex, birth order and number of child birth (singleton & multiple birth). The rate of extramarital birth was 1.8 percent and 2.1 percent in 2010-11. The incidence of LBW was 8.1 percent in extramarital birth and 5.0 percent in marital birth. The incidence of PTB in extramarital birth were 8.2 percent and 5.8 percent in marital birth. Compared with marital birth, the odds ratio (OR) for PTB were 1.48 (95% CI: 1.43-1.54) for extramarital birth. Risk of LBW was higher in extramarital birth (OR: 1.70, 95% CI: 1.64-1.76) than that of marital birth. Among mothers younger than 20 years, the odds ratio of PTB among extramarital birth, relative to married birth was 1.69 (1.49-1.91). Among unmarried mothers, those at a higher risk of LBW was aged 20-29 years (1.69: 1.59-1.79). Maternal unmarried status was associated with increased risk of PTB and LBW.

• Korea journal of population studies
• /
• v.17 no.2
• /
• pp.77-97
• /
• 1994

Despite the fact that the national family planning program in korea has accomplished its primary goals of fertility reduction and universal contraceptive use, the induced abortion is still high and there has been an increasing trend in the population sex ratio at birth. It seems that the changes in the imbalance of sex ratio have originated from traditonal boy preference. This indicates that much of the current family planning program can be overhauled, so that the program quality could be better controlled, by preventing the number of unwanted pregnancies and the imbalance of sex ratios. This paper aims, therefore, to examine the determinants of induced abortion through the investigation of pregnancy outcomes and their changes over time and to study the interaction between induced abortion, boy preference and the imbalance of sex ratio in Korea. The abortion rate had increased rapidly until the mid-1980s when there were about the same number of abortions as live births. Thereafter, the abortion rate has been maintained at this high level. By parity it shows a much higher abortion rate for a higher parity at all time. From the first parity, the sex composition of previous children stands out as the most important factor in deciding the pregnancy outcome at all time. The probability of a pregnancy ending in an abortion increases substantially when parents already had a son. The decline of the desired family size and the sustained strong son preference has made the sex of children a more important factor in the determination of the pregnancy outcome. Women's education has had consistently positive effects on the probability of a pregnancy ending in an abortion, but the effect shows a steady decline over time. The premarital pregnancy and urban residence also increase the abortion probability. This study suggests that the main concerns of the family planning program should be to strengthen the social support policies so as to weaken the son preference value leading to a balanced sex ratio and prevention of induced abortions.

• Journal of Korean Medical Science
• /
• v.33 no.50
• /
• pp.318.1-318.10
• /
• 2018

Background: In this prospective cohort study, we investigated the association between fatty acid ethyl esters (FAEEs) in meconium as biomarkers of prenatal ethanol exposure and growth deficits, as birth outcomes, that constitute several of the key cardinal features of fetal alcohol syndrome. Methods: A total of 157 meconium samples were collected from enrolled infants within 24 hours of birth, and nine FAEEs were quantified using liquid chromatography/tandem mass spectrometry. The relationships between cumulative concentrations of nine species of FAEEs in meconium and birth parameters of growth (age-sex-specific centiles of head circumference [HC], weight, and length) and respective and combined birth outcomes of growth deficits (HC ${\leq}10th$ centile, weight ${\leq}10th$ centile, and length ${\leq}10th$ centile) were determined. Results: Multivariate logistic regression analysis demonstrated that higher cumulative concentrations of meconium FAEEs correlated with elevated risks for HC and length, both, 10th percentile or less (adjusted odds ratio [aOR], 2.94; 95% confidence interval [CI], 1.12-7.74; P = 0.029) and HC and weight and length, all of them, 10th percentile or less (aOR, 3.27; 95% CI, 1.12-9.59; P = 0.031). Conclusion: The elevated cumulative FAEEs in meconium were associated with combined growth deficits at birth, specifically HC and length, both, 10th percentile or less, which might be correlated with detrimental alcohol effects on fetal brain and bone development, suggesting a plausible alcohol-specific pattern of intrauterine growth restriction.

• Asian-Australasian Journal of Animal Sciences
• /
• v.15 no.9
• /
• pp.1371-1377
• /
• 2002

During a 5-yr period, 1994-1998, pre-weaning and weaning data were collected on 591 calves produced by mating either straightbred Jersey, straightbred Limousin or $F_1$ (Limousin${\times}$Jersey) bulls to mature purebred Jersey or Limousin cows. Traits recorded included birth and weaning weight, height, length, girth, fat depth and a measure of muscle (ratio of stifle to hip width expressed as a percentage). All traits were analyzed assuming a model with sire and dam random effects that included effects of year and date of birth, sex, breed and year${\times}$sex interaction. Main effects were generally significant with few exceptions. Direct genetic effects were large for weight, height, girth and muscle with a breed trend from purebred Jersey (small) to purebred Limousin (large). At weaning, the maternal effect of the Jersey dam was positive for weight (10.9${\pm}$4.9 kg), girth (3.7${\pm}$1.0 cm) and muscle (6.0${\pm}$0.9%). Heterosis was highly significant and positive only for fat depth (1.5${\pm}$0.2 mm) with the $F_1$ progeny being the fattest, followed by the backcrosses, then purebred Jersey and purebred Limousin. Also, significant (p<0.001) but negative heterosis was observed for weight, girth and muscle. The change in ranking for fat depth relative to other traits is a reflection of the large heterotic effects relative to direct effects on fat depth. Epistatic effects were not significant on any trait at birth or weaning. This study has indicated the possibility of exploiting the positive heterotic and maternal effects for fat depth and muscularity to meet specific meat quality and quantity demand by consumers.

• Korean Journal of Veterinary Research
• /
• v.15 no.2
• /
• pp.187-198
• /
• 1975

Although considerable research has been done on the blood chemistry of domestic animals, little work has been made of the changes associated with age. Moreover, the records about physiology of the goat were not much available in Korea, and a comprehensive survey of the blood values of the Korean native goat has not been made. The object of the present investigation was to make good this deficiency and to suggest standards for the blood chemical values of Korean native goats from birth to maturity. The goats were kept under average farming conditions in Korea. Blood samples were collected from the jugular vein at birth, at one and four days, at one, two, three and four weeks, and at two, three, six, nine and twelve months of age. The results obtained in this work were summarized as follows: 1. The highest concentration of serum glucose was observed at birth and it decreased gradually until three months of age, showing a steady state thereafter. 2. The concentration of total serum protein was a little higher at one day of age than at birth and showed a steady state until seven days of age; then it decreased slightly at two weeks of age and recovered at three weeks of age and showed a steady state until twelve months of age. The concentration of serum albumin was increased a little at one day of age and revealed a steady state thereafter. The concentration of serum globulin showed three phases - a fall during the first two weeks to reach minimum, a rise to the fourth week, and a fall at two months of age, showing a steady state thereafter. The lowest value of albumin fraction was observed at birth, then the value increased gradually until three months of age and revealed a stealer state thereafter. The highest value of globulin fraction was observed at birth, then the gradual decrease of the value was seen until three months of age; thereafter the value showed a steady state. 3. Albumin/globulin ratio was the minimum at birth, then it increased to reach a maximum at two weeks of age and decreased a little thereafter. 4. The concentration of total serum cholesterol showed a gradual increase during the first three months and fell to reach adult revel at six months of age. 5. Urea nitrogen in serum decreased during the first week to reach a minimum, then it increased at three months of age, and showed a fell to mature level at six mouths of age. 6. The concentration of serum creatinine was not affected by age. 7. The concentration of total serum calcium was a little higher during the first two weeks than the other period during the first year of life. 8. The concentration of serum inorganic phosphorus showed a gradual rise to reach a maximum and a gradual fall to reach adult level at nine months of age. 9. No significant sex differences of serum chemical values were recognized.

• Current Research on Agriculture and Life Sciences
• /
• v.3
• /
• pp.158-165
• /
• 1985

The study was conducted to obtain some genetic information for breeding of mice. Average performance, heterosis and genetic variance were estimated with 362 progenies from a full diallel cross of four lines of mice (BALB/c, CBA, C3H and C57BL). The progenies were reared at the Experimental Animal Farm. College of Agriculture, Kyungpook National University from November, 1984 to February, 1985. Data for litter size. sex ratio, body weight and weaning rate were analyzed into heterosis effects, and genetic variance with Hayman's model. The results obtained are summarized as follows : 1. Average performance was 7.54 in litter size, 53.20 % in sex ratio, 1.55 g in birth weight, 10.45 g in weaning weight and 94.13 % in weaning rate. 2. The estimated heterois was 6.97% in litter size, 7.26 % in sex ratio, 6.08% in birth weight, 3.54% in weaning weight and 2.05% in weaning rate, respectively. 3. Additive gene effects were not observed in litter size, sex ratio, birth weight, weaning weight and weaning rate. In litter size and weaning weight, dominance effects were observed, which were shown due to individual crosses in litter size and were shown mean dominance effects of parental line in weaning weight. Mat-Maternal effects appeared in birth weight and weaning weight, and reciprocal effects were observed in weaning weight.