• Research in Plant Disease
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• v.7 no.1
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• pp.25-30
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• 2001

Influence of soil flooding with organic matters amendment at various temperatures on population changes of fungi, including Fusarium, and bacteria in ginseng-replanting field soils was examined to evaluate the effective flooding conditions for reducing the progress of ginseng root rot. Populations of Fusarium spp. and total fungi in flooded soils declined with days after flooding. The higher was the temperature in range of 20$\^{C}$ to 35$\^{C}$, the greater was the effect of flooding on the decrease of the fungal population. Flooding of soils with organic matters amendment had synergistic effect on the decrease of the fungal population at the same temperature; Fungal populations in flooded soils with and without organic matters amendment were reduced to 1/100 and 1/10, respectively, relative to those in non-flooded soils after 60 days of treatment at 30$\^{C}$. rice straw seemed to be more effective than greens. Population changes of total bacteria in flooded soils were similar to the trend of total fungi. However, the flooding seemed to influence less effect on the bacterial population than on the fungal population. Based on these experiments, we suggest than the progress of ginseng root rot in ginseng-replanting field soils may be significantly reduced by flooding them for longer than 3 months near at 30$\^{C}$ after amendment of organic matters.

• Korea journal of population studies
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• v.21 no.2
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• pp.5-36
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• 1998

This study examines the change of female labor market structure during the last several decades, focusing the effects of demographic factors such as declining fertility and increasing educational attainment of women. Women of the recent cohort tend to postpone their first marriages, to attain higher levels of education, and to have smaller number of children than women of the old cohort. This demographic trend results in the change of the population compositions in a way that population subgroups with high labor force participation have been increased. In addition, women of each population subgroup supply their labor in the market with higher rate than their old cohort counterparts. The labor force participation rate of highly educated women, and of married women has been increased faster than that of women with low education and of unmarried women. Although childbirth is still one of the most critical barrier for the women's participation, more and more women with young children tend to work for pay than ever before. In spite of the demographic change which is supportive to the increasing labor force participation, the Korean labor market have lost its female participants for the last year of the economic restructuring, reflecting demand-side factors as well as demographic factors are essential to determine the labor force participation of women.

• Korea journal of population studies
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• v.16 no.2
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• pp.125-139
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• 1993

Korea has successfully achieved a lowered fertility level owing to the strong population control policy and effective family planning program. Along with fertility decline and decreased number of children in family, average number of household members has decreased and nontraditional households such as one person household and households composed of unrelated individuals have prolifirated, even though the absolute number of them are found minimal in Korea. However in recent years several data and survey results suggest that one person households are gradually in the increasing trend. The study aimed at investigating the real state of one person households in Korea and next analyzing the proportional distribution of one person households by a few socioeconomic characteristics, thus providing basic for eatablishing far-singhted population and social welfare policy in the future. Korea has experienced high growth rate of economy through government-led development plans starting from the 1960s. During the past three decades, Korea has shifted from the agricultural state to the industrialized one. In compliance with the economic growth, urbanization and industrialization have brought about rural-to-urban migration and a great bulk of young population migrated to urban areas, who are seeking for educational and job opportunities. Korean society has also been under drastic change in every aspect of life involving norms, tradition, and attitude, etc. Therefore, in spite of the prejudice on 'living alone' still remaining, young people gradually leave parents and home, and further form nontraditional households in urban areas. Current increase in the number of one person households is partly attributable to the increase in high female educational attainment and female participation in economic activities. As the industrial structure in Korea changes from primary into secondary and tertiary industries, job opportunities for service/sales and manufacturing are opened to young female labor force in the process of industrialization. Contrary to the formation of one person households by young people, the aged single households are composed when children in family leave one by one because of marriage, education, employment. In particular, a higher proportion of aged female single households occur in rural areas due to the mortality difference by sex. Based on the data released form the 1990 Population and Housing Census and National Fertility and Family Health Survey in 1985 and 1991, the study tried to examine the state of one person households in Korea. According to Census data, the number of one person households increased to 1, 021, 000 in 1990, comprising 9.0 percent of total households. And the survey reveal that among total 11, 540 households, 8.0 percent, 923 households, are composed of one person households. Generally, the proportion of female single households is greater than that of male ones, and a big proportion of one person households is concentrated in the 25-34 age bracket in urban areas and 65 years and more in rural areas. It is shown than one person householders in urban areas have higher educational attainment with 59.2 percent high schooling and over in 1991, Job seeking proved to be the main reason for leaving home and forming one person households. The number of young female single households with higher education and economic self-reliance are found nil and the study did not allow to analyze the causal realtionship between female education and employment and one person household formation. However more research and deep analysis on the causal facors on one person household formation using statistical method are believed to be necessary.

• Health Policy and Management
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• v.27 no.1
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• pp.75-79
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• 2017

Suicide is becoming a public health issue in many countries, and even more so in Korea. Korea has the highest suicide rate in the Organization for Economic Cooperation and Development countries. To address these issues, we investigated the recent trends in suicidal ideation and suicide attempts among the adult population. We used data from four sources: Korean National Health and Nutrition Examination Survey (KNHANES, '2007-2012, '2013, '2015), Korean Community Health Survey (KCHS, '2008-2009, '2013), Korean Wealth Panel Study (KOWEPS, '2012-2015), and Korea Health Panel Survey (KHP, '2010-2013). Weighted frequencies and trend tests were used. The rate of suicidal ideation as recent year was 5.10% (KNHANES, '2015), 8.95% (KCHS, '2013), 2.34% (KOWEPS, '2015), or 5.39% (KHP, '2013). Regarding the suicide attempts, the rate of suicide attempts as recent year was 0.61% (KNHANES, '2015), 0.41% (KCHS, '2013), or 0.04% (KOWEPS, '2015). Average percent change of suicidal ideation during survey year was -2.80% (KNHANES, '2007-2012), 5.78% (KNHANES, '2013-2015), 0.62% (KCHS, '2008-2013), -5.63% (KOWEPS, '2012-2015), and -10.94% (KHP, '2010-2013). Average percent change of suicide attempts during survey year was -3.84% (KNHANES, '2007-2012), 4.55% (KNHANES, '2013-2015), -2.54% (KCHS, '2008-2013), and -18.96% (KOWEPS, '2012-2015). Those who had lower income level were more likely to have self-reported suicidal ideation and suicide attempts. Our results suggest that further efforts are needed for more effective intervention to identify and manage low income strata with suicide problem.

• Nutrition Research and Practice
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• v.14 no.2
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• pp.152-159
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• 2020

BACKGROUND/OBJECTIVES: Hypertriglyceridemia may be a more important predictor of cardiovascular disease in Asian population consuming carbohydrate-rich foods than in Western populations. Dairy products are known to play a beneficial role in obesity, dyslipidemia, and metabolic syndrome, but the results vary depending on gender and obesity. In this study, we investigated the associations between dairy product intake and hypertriglyceridemia in Korean adults. SUBJECTS/METHODS: The participants were selected from the Korea National Health and Nutrition Examination Survey 2007-2012 (KNHANES IV and V). A total of 22,836 participants aged 19-64 years were included in the analysis. A food frequency questionnaire used to determine the frequency of consumption of products (milk and yogurt). Multivariable logistic regression was used to assess the associations between dairy product intake and hypertriglyceridemia. RESULTS: A significantly decreased risk of hypertriglyceridemia was detected in the highest dairy product intake frequency group (≥ 1 time/day) (odd ratio [OR] = 0.79; 95% confidence interval [CI] 0.64-0.97, P for trend = 0.022) compared to that for the lowest dairy product intake frequency group. Among obese participants, the group with the highest intakes of milk (in men, OR = 0.64; 95% CI: 0.46-0.91, P for trend = 0.036) and yogurt (in women; OR = 0.53; 95% CI: 0.29-0.94, P for trend = 0.019) showed inverse associations with hypertriglyceridemia. No associations were detected in normal weight participants. CONCLUSION: The association between dairy product intake and hypertriglyceridemia differed by gender and obesity status. Further prospective studies are needed to confirm these associations.

• Journal of Preventive Medicine and Public Health
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• v.47 no.4
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• pp.216-229
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• 2014

Objectives: This study aims to investigate trends of cardiovascular disease (CVD) risk factor profiles over 17 years in percutaneous coronary intervention (PCI) patients at the Mayo Clinic. Methods: We performed a time-trend analysis within the Mayo Clinic PCI Registry from 1994 to 2010. Results were the incidence and prevalence of CVD risk factors as estimate by the Framingham risk score. Results: Between 1994 and 2010, 25 519 patients underwent a PCI. During the time assessed, the mean age at PCI became older, but the gender distribution did not change. A significant trend towards higher body mass index and more prevalent hypercholesterolemia, hypertension, and diabetes was found over time. The prevalence of current smokers remained unchanged. The prevalence of ever-smokers decreased among males, but increased among females. However, overall CVD risk according to the Framingham risk score (FRS) and 10-year CVD risk significantly decreased. The use of most of medications elevated from 1994 to 2010, except for ${\beta}$-blockers and angiotensin converting enzyme inhibitors decreased after 2007 and 2006 in both baseline and discharge, respectively. Conclusions: Most of the major risk factors improved and the FRS and 10-year CVD risk declined in this population of PCI patients. However, obesity, history of hypercholesterolemia, hypertension, diabetes, and medication use increased substantially. Improvements to blood pressure and lipid profile management because of medication use may have influenced the positive trends.

• Structural Engineering and Mechanics
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• v.66 no.6
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• pp.677-691
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• 2018

Reliability assessment of complex structures using simulation methods is time-consuming. Thus, surrogate models are usually employed to reduce computational cost. AK-MCS is a surrogate-based Active learning method combining Kriging and Monte-Carlo Simulation for structural reliability analysis. This paper proposes three modifications of the AK-MCS method to reduce the number of calls to the performance function. The first modification is related to the definition of an initial Design of Experiments (DoE). In the original AK-MCS method, an initial DoE is created by a random selection of samples among the Monte Carlo population. Therefore, samples in the failure region have fewer chances to be selected, because a small number of samples are usually located in the failure region compared to the safe region. The proposed method in this paper is based on a uniform selection of samples in the predefined domain, so more samples may be selected from the failure region. Another important parameter in the AK-MCS method is the size of the initial DoE. The algorithm may not predict the exact limit state surface with an insufficient number of initial samples. Thus, the second modification of the AK-MCS method is proposed to overcome this problem. The third modification is relevant to the type of regression trend in the AK-MCS method. The original AK-MCS method uses an ordinary Kriging model, so the regression part of Kriging model is an unknown constant value. In this paper, the effect of regression trend in the AK-MCS method is investigated for a benchmark problem, and it is shown that the appropriate choice of regression type could reduce the number of calls to the performance function. A stepwise approach is also presented to select a suitable trend of the Kriging model. The numerical results show the effectiveness of the proposed modifications.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.2
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• pp.557-562
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• 2016

Background: Lung cancer is one of the most common cancers in the world and a major cause of death from cancer. One of the important indicators to compare the prevalence and incidence of the disease is a change in the trend. The aim of this study was to investigate the changes in the incidence of lung cancer in Iran. Materials and Methods: This study was conducted based on existing data obtained from a national registry of cancer cases and the Disease Management Center of Ministry of Health in Iran. All cases registered in the country were included during 2003-2008. Incidence rates were reported based on the direct method and standard population of World Health Organization. The study also examined the morphology of common lung cancers. Trends in incidence underwent joinpoint regression analysis. Results: Based on the results of this study, 14,403 cases of lung cancer have been recorded of which 10,582 cases were in men and 3,821 in women. Highest incidence rates were observed in the 80-84 age group. Considerable variation across provinces was evident. In females squamous cell carcinoma (SCC) demonstrated a reduction from 24% to 16% of lesions over the period of study, while adenocarcinoma rose from 21% to 29%. In males a similar reduction in SCC was apparent (42% to 29%, again with increase in AC (13 % to 18%). Conclusions: The results show that the increase in the incidence of lung cancer the trend is that more men than women and in men and may be caused by changes in smoking pattern. The incidence of lung cancer in the North West and West provinces was higher than in other regions.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.18
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• pp.7879-7884
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• 2014

To investigate the association between intake of freshwater fish and their fatty acids and the risk of breast cancer in Chinese women, we conducted a case-control study with 669 cases and 682 population-based controls in Jiangsu Province of China. A structured questionnaire was used to elicit detailed information. Unconditional logistic regression analysis was performed to calculate odds ratios (ORs) and 95% confidence intervals (CIs). Total freshwater fish intake was linked to decrease in the adjusted OR for breast cancer, but without dose-dependence. Analyses by freshwater fish species showed that consumption of black carp and silver carp was inversely related to breast cancer risk, with adjusted-ORs for the highest intake category of black carp (${\geq}500g/month$) of 0.54 (95%CI=0.33-0.92; $P_{trend}$ <0.002) and for silver carp (${\geq}1000g/month$) of 0.19 (95%CI=0.11-0.33; $P_{trend}$ <0.001). In contrast, consumption of crucian carp was positively related to breast cancer risk, with an adjusted OR for the highest intake category (${\geq}1000g/month$) of 6.09 (95%CI=3.04-12.2; $P_{trend}$ <0.001). Moderate intakes of SFA, PUFA, n3-PUFA and n6-PUFA from freshwater fish may decrease the risk of breast cancer among premenopausal women. The findings of this study suggest that intake of freshwater fish and their fatty acids may modify risk of breast cancer, and that different species of freshwater fish could have a different actions on breast cancer risk. Future epidemiologic studies are needed to know the effects of freshwater fish intake on breast cancer risk and the cause of these effects.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.8
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• pp.3097-3100
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• 2015

Projections of cancer cases are particularly useful in developing countries to plan and prioritize both diagnostic and treatment facilities. In the prediction of cancer cases for the future period say after 5 years or after 10 years, it is imperative to use the knowledge of past time trends in incidence rates as well as in population at risk. In most of the recently published studies the duration for which the time trend was assessed was more than 10 years while in few studies the duration was between 5-7 years. This raises the question as to what is the optimum time period which should be used for assessment of time trends and projections. Thus, the present paper explores the suitability of different time periods to predict the future rates so that the valid projections of cancer burden can be done for India. The cancer incidence data of selected cancer sites of Bangalore, Bhopal, Chennai, Delhi and Mumbai PBCR for the period of 1991-2009 was utilized. The three time periods were selected namely 1991-2005; 1996-2005, 1999-2005 to assess the time trends and projections. For the five selected sites, each for males and females and for each registry, the time trend was assessed and the linear regression equation was obtained to give prediction for the years 2006, 2007, 2008 and 2009. These predictions were compared with actual incidence data. The time period giving the least error in prediction was adjudged as the best. The result of the current analysis suggested that for projections of cancer cases, the 10 years duration data are most appropriate as compared to 7 year or 15 year incidence data.