• Geophysics and Geophysical Exploration
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• v.2 no.3
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• pp.142-148
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• 1999

Three-dimensional electromagnetic modeling algorithm in homogeneous half-space was developed using the extended Born approximation to an electric field integral equation. To examine the performance of the extended Born approximation algorithm, the results were compared with those of the full integral equation results. For a crosshole source-receiver configuration, the agreement between the integral equation and the extended Born approximation was remarkable when the source frequency is lower than 20 kHz and conductivity contrast lower than 1:10. Beyond this conductivity contrast, the simulated results by the extended Born approximation exhibit a difference with respect to those by the integral equation. Therefore, the limit of accuracy lies below contrast of 1:10 in the extended Born approximation. Since for the source frequency range from 20 kHz to 100 kHz, however, the difference is relatively small, the extended Born approximation could be used for a reasonable 3-D EM modeling algorithm.

• Proceedings of the Optical Society of Korea Conference
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• 2007.02a
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• pp.319-320
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• 2007

• Journal of health informatics and statistics
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• v.43 no.4
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• pp.255-266
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• 2018

Objectives: This study compared the risk of preterm birth and low birth weight between native-born and foreign-born women. Methods: By Using the birth registration data, every woman who gave birth between 2010 and 2016 in Korea was included in the analysis. Duration from marriage to pregnancy was measured by month and multiple socioeconomic and demographic characteristics were controlled. Preterm birth (<37 weeks) and low birth weight (<2.5 kg) were used for outcome variables. Descriptive statistics and logistic regression were used for data analysis with Stata. Results: The risks of preterm birth and low birth weight for native-born and foreign-born women differed according to the duration of marriage or birth order. For the first infant, foreign-born women were more likely to have pereterm birth or low birth weight than the native-born in the early stage of marriage but nativeborn women had higher risks than the foreign-born in the middle and later stage of marriage. For the second infant, foreign-born women were less likely to have pereterm birth or low birth weight than the native-born regardless of the duration of marriage. Conclusions: The results of this study demonstrates that the risk of preterm birth and low birth weight for foreign-born women is concentrated on the early stage of marriage. Institutional and cultural supports should be given to foreign-born women to help their early settlement in the Korean society.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.10
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• pp.1475-1478
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• 2005

Statistical analysis was conducted on sow stillbirth traits of three genotypes with 2,400 litters including the Erhualian, Large White and the $F_1$ cross of these two breeds. Number of stillborn piglets per litter in the Erhualian, Large White and the $F_1$ averaged 0.85, 0.31 and 0.70, and percentage born alive averaged 95.0%, 97.0% and 95.5%, respectively. Erhualian sows with a greater litter size also had a higher stillbirth rate. Results of analysis of variance indicated that genotype, parity, farrowing year${\times}$farrowing season interaction and total number born had highly significant effects on both number of stillborn piglets per litter and percentage born alive in sows (p<0.0001). Farrowing year had no significant effect on number of stillborn piglets per litter (p>0.05), and highly significant effect on percentage born alive (p<0.01). Farrowing season had highly significant effects on both number of stillborn piglets per litter and percentage born alive (p<0.01). From parity one to parity ten, least squares means for number of stillborn piglets per litter progressively increased with increasing parity and least squares means for percentage born alive progressively decreased with increasing parity. Sows that farrowed in winter had the highest number of stillborn piglets per litter and the lowest percentage born alive, sows that farrowed in autumn had the lowest number of stillborn piglets per litter and the highest percentage born alive. With increasing total number born, least squares means for number of stillborn piglets per litter markedly increased and least squares means for percentage born alive markedly decreased. Results from analysis of paternal half sibs indicated that the heritabilities for number of stillborn piglets per litter and percentage born alive were 0.110 and 0.124, and the genetic, phenotypic and environmental correlations between them were -0.989, -0.951 and -0.948, respectively. These results indicated that number of stillborn piglets per litter and percentage born alive were traits with the similar genetic background.

• Geophysics and Geophysical Exploration
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• v.4 no.3
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• pp.70-79
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• 2001

The integral equation method is a powerful tool for numerical electromagnetic modeling. But the difficulty of this technique is the size of the linear equations, which demands excessive memory and calculation time to invert. This limitation of the integral equation method becomes critical in inverse problem. The conventional Born approximation, where the electric field in the anomalous body is approximated by the background field, is very rapid and easy to compute. However, the technique is inaccurate when the conductivity contrast between the body and the background medium is large. Quasi-linear, quasi-analytical and extended Born approximations are novel approaches to 3-D EM modeling based on the linearization of the integral equations for scattered EM field. These approximation methods are much less time consuming than full integral equation method and more accurate than conventional Born approximation. They we, however, still approximate methods for 3-D EM modeling. Iterative series methods such as modified Born, quasi-linear and quasi-analytical can be used to increase the accuracy of various approximation methods. Comparisons of numerical performance against a full integral equation and various approximation codes show that the iterative series methods are very accurate and almost always converge. Furthermore, they are very fast and easy to implement on a computer. In this study, extended Born series method is developed and it shows more accurate result than that of other series methods. Therefore, Iterative series methods, including extended Born series, open principally new possibilities for fast and accurate 3-D EM modeling and inversion.

• Journal of Korean Academy of Nursing
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• v.1 no.1
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• pp.49-58
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• 1970

For the purpose to clarify the effects of the mothers health during pregnancy on the weight and length of the newborn infants, this study was carried out on 500 new born infants delivered at St, Mary's Hospital, Ewha Woman's University Hospital and Red Cross Hospital in Seoul during the eight-month period from March, 1969 to October, 1969. In this study, the relationship between the T weight and length of the new born infants, and in each case, the weight, length, age, duration of labour, duration of pregnancy, weight gain during pregnancy and diets level during pregnancy of the mother were observed. The relationship between the weight and length of the new born infants and the parity n-as also observed. The results obtained in this study were as follows. 1. The weight of new born infants of both sexes was significantly correlated with the parity, the weight of the mother, and the duration of labour of the primipara. The weight of the mother and the duration of pregnancy were significantly correlated with the weight of the male new born infants only, and the weight of the new born infants and the weight gain of the mother during pregnancy were significantly correlated in the female new born infants. 2. In general, the weight of the new born infants of well or excellently nourished mothers were heavier than those of poorly nourished ones. 3. The length of the new born infants was significantly correlated mother the duration of labour in the primipara.

• Journal of Labour Economics
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• v.35 no.1
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• pp.1-19
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• 2012

This paper estimated the first-born effects on wage among wage and salary workers born in 1954 to 1973 with the 2003 KLIPS data set. The first-born effect on wage was estimated as 7.3% with the parsimoniously specified wage function using age and gender. Adding various variables as independent variables, the effects were estimated statistically insignificantly differently, the effect was estimated as 7.6% with adding education, tenure, marital status, father's education, the number of siblings, and health. The effect is not statistically significantly different from that of the parsimoniously specified wage function. We estimated the first-born effects of male, and female wage and salary workers separately. The first-born effects of male wage and salary workers were estimated as 5.9~8.8%. The first-born effects of female wage and salary workers were estimated as 8.8~9.9%.

• The Journal of Economics, Marketing and Management
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• v.9 no.5
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• pp.27-37
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• 2021

Purpose: By foreshadowing the historical background and cultural influence of Korean food and economic development in China, this paper demonstrates Chinese market entry strategies taken by TheBorn with its company history and CEO's background. Research design, data and methodology: The eclectic paradigm was utilized to analyze ownership, localization, and internalization advantages for TheBorn's first entry into the Chinese market. The research answers how TheBorn could expand its business in the early 2000s while most were skeptical about the globalization of Korean food. Results: First, possessing various restaurant franchises, food patents, and developments, and media use enabled to achieve a strong ownership advantage. Second, the Chinese market is conveniently located in South Korea. Thus, TheBorn could exercise direct management to its overseas restaurant to maintain the food quality and service. Lastly, establishing a sauce manufacturing plant and its branch company accelerated further expansions to other Chinese cities. Conclusions: Based on those success factors, TheBorn extended its business into different cities in China and emerged as a franchisor giant in the Korean restaurant franchise industry.

• Journal of Preventive Medicine and Public Health
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• v.53 no.6
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• pp.409-418
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• 2020

Objectives: This study conducted an age-period-cohort (APC) analysis of trends in healthy lifestyle behaviors in Japan. Methods: We used National Health and Nutrition Survey data on salt intake and prevalence of smoking, drinking, and physical activity between 1995 and 2018 in Japan. Age groups were defined from 20 years to 69 years old in 10-year increments. Cohorts were defined for each age group of each year with a 1-year shift, and cohorts born in 1926-1935 (first cohort) until 1989-1998 (last cohort) were examined. We conducted a Bayesian APC analysis, calculating estimated values for each behavior by age group, period, and cohort. Results: Estimated salt intake decreased from cohorts born in the 1930s to the 1960s, but increased thereafter in both genders, and the magnitude of increase was larger for men. Estimated smoking prevalence increased in the cohorts starting from the 1930s for men and the 1940s for women, and then decreased starting in the cohorts born in the 1970s for both genders. Although estimated drinking prevalence decreased starting in the cohorts born in approximately 1960 for men, for women it increased until the cohorts born in approximately 1970. Estimated physical activity prevalence decreased starting in the cohorts born in the 1940s in both genders, but the magnitude of decrease was larger for women. Conclusions: Trends in cohort effects differed by gender, which might be related to changes in the social environment for women. Improvements in dietary and exercise habits are required in more recently born cohorts of both genders.

• Journal of Preventive Medicine and Public Health
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• v.52 no.1
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• pp.66-70
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• 2019

Objectives: In the Republic of Korea (ROK), the notified incidence of tuberculosis in foreign-born individuals (NITFBI) has increased recently, as has the rate of multidrug-resistant (MDR) and rifampicin-resistant (RR) tuberculosis in foreigners staying in the ROK. As Jeju Province in ROK has a no-visa entry policy, control programs for NITFBI should be consolidated. The aim was to evaluate the status of NITFBI, with a focus on the distribution of MDR/RR tuberculosis by nationality. Methods: Data on tuberculosis incidence in individuals born in Jeju Province and in foreign-born individuals were extracted from the Korean Statistical Information Service of Statistics Korea, and the Infectious Disease Surveillance Web Statistics of the Korea Centers for Disease Control and Prevention, respectively. Results: Among all notified incident cases of tuberculosis, the proportion of NITFBI increased from 1.46% in 2011 to 6.84% in 2017. China- and Vietnam-born individuals accounted for the greatest proportion of the 95 cases of NITFBI. Seven cases of MDR/RR tuberculosis were found, all involving patients born in China. Conclusions: In Jeju Province, ROK, NITFBI might become more common in the near future. Countermeasures for controlling active tuberculosis in immigrants born in high-risk nations for tuberculosis should be prepared in Jeju Province, since it is a popular tourist destination.