• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.5
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• pp.343-346
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• 2000

Rye breeding using F$_1$ hybrid began about 30 years ago, when cytoplasmically inherited forms of male sterility (CMS) and corresponding nuclear restorers were detected. It is very important to produce inbred lines for making hybrid lines because of strong self-incompatibility in rye. Among the 456 rye germplasms used in hybrid breeding scheme, 24 lines (5.3%) had the above 60% of self-fertility, and six lines of them were selected for their good agronomic characteristics and were used for subsequent inbreeding program. The average self-fertility of selected six lines was 78.4%, ranging from 72.2 to 99.5%. Genetic analysis for the self-fertility using $F_2$ populations showed that the segregation of self-fertile and sterile plants in F$_2$populations could be fit into 3 to 1 ratio suggesting self-fertility in rye be controlled by one major gene. The four different self-fertile lines, PI237923, 5C11, 5G5 and Florida black, had the same self-fertility gene because their F$_2$ plants showed almost the same self-fertility as their parents and showed no genetic segregation.

• Korea journal of population studies
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• v.11 no.1
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• pp.87-96
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• 1988

The subjects used in this study were chosen from self-employed women in Taegu City, Korea, Data for 415 respondents were collected by face-to-face interviews conducted during the period of November 10 through 23, 1987. There are three major purposes in this study : first, to describe the general characteristics of self-employed Korean women's fertility behavior ; second, to examine the determinants of fertility behavior among self-employed women : third, to explore the relative importance of the fertility determinants among the women. Regression analyses were introduced to test hypotheses. Nine variables, such as household income, educational attainment, mass media, abortion, the period of contraception practice, contraceptive expenses, the number of infant, deaths marital period, and age at first marriage were introduced as indicators in the regression. The results of this study show that there are negative relationships between the dependent variable of fertility and abortion, and the period of contraception practice. On the other hand, positive relationships between the dependent variable of fertility and the number of infant deaths, and marital period and age at first marriage are shown in this study. However, the results of this study show that there are insignificant relationships between socioeconomic variables and fertility. From the results of the F test to evaluate the significance of difference in $R^2$between two different regression equations, we have found that the regression equation including both socioeconomic variables and intermediate variables is misspecified to examine the determinants of fertility behavior among self-employed Korean women. That is, the F test shows that the regression equation including only intermediate variables as indicators is the best model for this study. Finally, the relative importance of the fertility determinants among self-employed women is found as follows : Age at the first marriage is the most influential variable in the fertility, and the next important factors are abortion, the period of contraception practice, the number of infant deaths, and marital period, in that order.

• Journal of Families and Better Life
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• v.31 no.3
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• pp.141-151
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• 2013

The purpose of this study is to test the economic rationality hypothesis of the low fertility trap among 412 college students at 13 private universities located in Seoul. The respondents were requested to complete the self-administered questionnaire, and the hierarchical multiple regression analyses were performed for analyzing the data. The major findings of this study were as follows: First, the students' views on the prospects for their future employability were 54.6% for big business, 64.51% for medium-sized business, and 49.63% for public sector. In the most employable job, the mean desired monthly salary was 3,505,400 won, while the mean expected monthly salary 2,753,600 won. Second, hierarchical regression analyses revealed that the family income in parental home was positively related to youths' consumption aspirations. Finally, the gap between youths' consumption aspirations and their expected income was negatively related to their desired number of children, while not significantly related to their planned age of first child birth. Thus, the low fertility trap hypothesis was supported in terms of birth rate drop, but not supported in terms of childbearing postponement. The implications of the study results are discussed.

• Journal of Korean Academy of Nursing
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• v.54 no.1
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• pp.59-72
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• 2024

Purpose: This cross-sectional study aimed to identify factors influencing the intention for continual fertility treatments among women undergoing assisted reproductive technology (ART). Methods: A total of 197 women were recruited through convenience sample from fertility hospitals in Gyeonggi-do and Busan, South Korea. Data were collected using a self-report questionnaire incorporating measures of uncertainty; Depression Anxiety Stress Scales; Fatigue Severity Scale; Coping Scale for Infertility-Women; spousal support; treatment environment; and intention for continual fertility treatment. Descriptive statistics, chi-square tests, t-tests, and logistic regression analysis were conducted using IBM SPSS 26.0. Results: As many as 70.6% of the participants expressed an intention for continual fertility treatments. Logistic regression analysis revealed that factors such as uncertainty (odds ratio [OR] = 0.44, 95% confidence interval [CI] 0.20~0.95), active coping (OR = 4.04, 95% CI 1.11~14.71), treatment environment (OR = 2.77, 95% CI 1.26~6.07), and the duration of marriage (OR = 2.61, 95% CI 1.24~5.49) were significantly related with this intention. Conclusion: These findings underscore the significance of uncertainty management, having proactive coping strategies, having supportive treatment environments, and considering the duration of marriage concerning women's intention for continual fertility treatment in the context of ART. The implications of these results extend to the development of nursing intervention programs aimed at providing crucial support for women undergoing ART and seeking to continue their infertility treatment.

• Journal of The Korean Society of Grassland and Forage Science
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• v.41 no.2
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• pp.77-83
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• 2021

Rye (Secale cereal L.) is the most tolerant to abiotic stress including low temperature, drought, and unfavorable soil conditions among the winter cereals. Rye is the rapid growth of early spring results from increasing areas for the use of the forage and green manure in the middle part of Korea. "Jungmo2509", a rye cultivar was developed by the National Institute of Crop Science (NICS), RDA in 2014. It was developed from a cross between "Olhomil", a self-compatible cultivar, and "Synthetic II", a self-incompatible line. "Jungmo2509" is an erect plant type and of a middle size, with a green leaf color, a yellowish-white colored culm, and a yellowish brown-colored, small-size grain. The heading date of "Jungmo2509" was April 23, which was 5 days later than that of "Gogu", respectively. But "Jungmo2509" showed greater resistance to lodging compared to that of the check cultivar, with similar to winter hardiness, wet injury, and disease resistance. "Jungmo2509" was a higher to than "Gogu" in terms of protein content (9.4% and 8.0%, respectively), total digestible nutrients (TDN) (55.7% and 55%, respectively). The seed productivity of "Jungmo2509" was approximately 2.08 ton 10a-1, which was 11% lower than that of the check. Almost all rye cultivars are out-crossing due to genes controlling incompatibility, but "Jungmo2509" is higher seed fertility (56%) than that of Gogu (0%). it has self-compatible genes. "Jungmo2509" is erect in plant type and resistance for lodging. Therefore, "Jungmo2509" can produce uniform seeds for processed grains of human consumption and utilize them as parents for breeding the rye hybrids with high forage yields.

• Journal of Families and Better Life
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• v.24 no.6 s.84
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• pp.161-176
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• 2006

The purpose of this study was to conduct a family impact analysis to examine the effects of policies to lower fertility in families in Korea. Data were collected from a purposive sample of three groups of government officials, family scholars, and staff at family-related organizations and associations. 105 family policy professionals responded to the self-report questionnaire. The family impact analysis scale was formulated by the researcher based on Ooms'(1995)'A checklist for assessing the impact of policies on families' and Lawson & Lawson's(2001)'An example on family impact analysis checklist or inventory.' The results showed there were eight factors in the family impact analysis on the policies to low fertility in Korea; strengthening family membership and stability; providing various convenient public services; recognizing family interdependence; recognizing the efficiency of implementing policies and support of vulnerable families; strengthening the family function of childbirth; recognizing family relationships; preventing family problems and empowering families; and recognizing family diversity. The conclusions and implications of these findings were also discussed.

• Biotechnology and Bioprocess Engineering:BBE
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• v.9 no.6
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• pp.440-446
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• 2004

Interest in in vitro study of entomopathogenic fungi, including Cordyceps species, has been increasing due to their valuable bioactive compounds and biocontrol effects. Among Cordyceps species, in vitro stromata of C militaris has been successfully produced and cultivated for industrial purposes. However, genetic study on in vitro stromata formation of C militaris has not been carried out yet. Here, relationship between mating system and perithecial stromata formation of C militaris is reported. Mating system was determined by observing perithecial stromata formation from mono-ascospore cultures and their pair-wise combinations. Certain combinations of mono-ascospore strains produced perithecial club-shaped stromata, whereas other combinations produced either no stromata or only abnormal non-perithecial stromata. Similarly, mono­ascospore cultures without combination produced either no stromata or only abnormal non­perithecial stromata. Despite obvious heterothallism, self-fertility was occasionally observed in few strains of C militaris. These observations indicated that C militaris behaves as a bipolar het­erothallic fungus and requires two mating compatible strains in order to produce regular club­shaped perithecial stromata, a fundamental requirement for its industrial cultivation.

• Journal of Korea Foundry Society
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• v.38 no.2
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• pp.27-31
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• 2018

The lack of industrial manpower that Korean companies have been suffering in 21st century is largely responsible for the low-fertility phenomenon. This research suggests an alternative solution with a program for fostering foreign laborers with technical skills in casting industry. Industrial manpower growth is feasible through accepting migrants who have had official education on the fundamental industrial technologies provided by Korean government. These technically trained migrants who can keep economical self-perpetuating ability are can help to effectively address the problem of the declining working-age population and the decreasing potential growth rate in Korea.

• Journal of Plant Biology
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• v.11 no.1
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• pp.33-37
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• 1968

Present investigation was carried out in order to make clear the fertility, morphological characters, and chromosome numbers of interspecific hybrids of Chrysanthemum Zauadskii, C. indicum, and C. lavandulaefolium. 1. Hybrids were not self-pollinated. When sib-crossed the fertility was 1.3~19.3%. 2. F2 individuals were variable in their morphological Characters. 3. Chromosome numbers of three putative parents were different from those reported previously: C. zawadskii 2n=36, C. indicum 2n=20, C. lavandulaefolium 2n=16, $C. indicum{\times}C. zawadskii 2n=28, C. zawadskii{\times}C. indicum-1 2n=28, C. zawadskii{\times}C. indicum-2 2n=28, C. zawadskii{\times}C. indicum-3 2n=28, C. zawadskii{\times}C. indicum-4 2n=28, C. zawadskii{\times}C. indicum-5 2n=28, C. zawadskii {\times}C. lavandulaefolium-1 2n=26, C. zawadskii{\times}C. lavandulaefolium-2 2n=26.$

• Korea journal of population studies
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• v.8 no.1
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• pp.118-138
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• 1985

This paper is aimed to analyse the recent changes in family planning as a step in an evaluation of the results of the population control policy which has been strenuously pursued by the government since December 1981. The data used in this analysis comes from the 1985 national fertility and family planning survey conducted by the Korea Institute for Population and Health (KIPH) in May 1985. According to the 1985 survey data, there have been great changes in both the contraceptive practice and fertility rates since the strengthening of the government's population control policy in 1 981. The contraceptive practice rate for married women aged 15-44 has increased from 57.7% in 1982 to 70.3% in 1985, an increase of 12.6% points in the short span of only 3 years. During the same period, the total fertility rate has declined from 2.7 in 1982 to the population replacement level which was planned to achieve by 1 988. More than 80% of women aged over 30 or with two children or more are practicing contraception, while the practice rates of women with 0-1 children are 14.0% and 45.1% respectively. The survey has revealed that the increase of contraceptive practice rate during 1982-1985 has mainly attributed to the high acceptance of sterilization procedures which practice rate of the married women has increased from 28.1% to 40.3% for the period. Also, the survey data shows that 24.7% of those women with only one child is practicing contraception for thepurpose of fertility termination. The government, taking into account of rapid changes in contraceptive practice and fertility rates, is formulating a population plan during the sixth fiveyear economic and social development plan (1987-1991) to achieve 1% ofpopulation growth rate by 1993, which was planned to realize by 2000. In order to meet this demographic goal, the existing population control policy measures should be improved to be suited to the recent contraceptive use and fertility changes. From this standpoint, the following considerations should be put forth; 1) improvement of the current program management systems including target allocation and evaluation schems for recruiting new acceptors in the young 20s groups to use contraceptives for birth spacing and to increase high continuation rates through the strengthening of follow-up services for the acceptors, 2) increase of self-supporting contraceptive users by promoting commercial advertisements on contraceptives through mass media including T.V. and radio, 3) development of social support policies including incentive schems, and strengthening of IE & C activities for increasing the proportion of the one-child family, 4) strengthening of population and family planning education in and out school youth, and 5) strengthening of management capabilities at the provincial and local program managers.