• Journal of the Korean Statistical Society
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• v.5 no.2
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• pp.143-158
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• 1976

The purpose of this article is, first, to argue that the fertility cannot be reduced rapidly through widerspread diffusion of contraceptive practices which has been the main drive of the national policy in population control, because there involves the inescapable externalites in procreation, second, family sizes tend to be larger because of the financial externalities arising from government subsidies to families with children, and finally, the decreasing relative risk aversion of households with wealth may induce the poor to have large family sizes.

• Communications for Statistical Applications and Methods
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• v.6 no.2
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• pp.487-500
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• 1999

We propose a class of hierarchical Bayes estimators of the error variance under the relative squared error loss in balanced fixed-effects two-way analysis of variance models. Also we provide analytic expressions for the risk improvement of the hierarchical Bayes estimators over multiples of the error sum of squares. Using these expressions we identify a subclass of the hierarchical Bayes estimators each member of which dominates the best multiple of the error sum of squares which is known to be minimax. Numerical values of the percentage risk improvement are given in some special cases.

• Physical Therapy Rehabilitation Science
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• v.7 no.3
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• pp.139-145
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• 2018

Objective: Older persons with diabetes mellitus (DM) are particularly more likely to have fallen in the previous year than those without DM. The purpose of this study was to investigate the relationship between the risk of falls and type 2 DM in older adults who are 65 years of age or above. Design: A systematic review. Methods: PubMed and other two databases were searched up to August 2, 2018. Observational and cohort studies evaluating fall risk in people who are 65 years of age or above with DM were included. This review extracted the following information from each study selected: first author's surname, year of publication, country, average follow-up period, sex, age at enrollment, study population, measurement variables, relative risk, 95% confidence intervals and controlled variables. Results: This review involved nine cohort studies with 3,765 older adults with DM and 12,989 older adults without DM. Six studies compared with or without DM and two studies compared fallers with non-fallers with DM. Risk factors for falls included impaired cognitive function, diabetes-related complications (peripheral nerve dysfunction, visual impairment), and physical function (balance, gait velocity, muscle strength, and severity of physical activities). Conclusions: People who are 65 years of age or above with DM have increased risk of falling caused by impaired cognitive function, peripheral nerve dysfunction, visual impairment, and physical function in community-dwellers. For adults who are 65 years of age or older with DM, research fields and clinical settings should consider therapeutic approaches to improve these risk factors for falls.

• Journal of Preventive Medicine and Public Health
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• v.48 no.6
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• pp.280-286
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• 2015

Objectives: Approximately 10% to 15% of lung cancer cases occur in never-smokers. Hormonal factors have been suggested to lead to an elevated risk of lung cancer in women. This systematic review (SR) aimed to investigate the association between hormonal replacement therapy (HRT) and the risk of lung cancer in women using cohort studies. Methods: We first obtained previous SR articles on this topic. Based on these studies we made a list of refereed, cited, and related articles using the PubMed and Scopus databases. All cohort studies that evaluated the relative risk of HRT exposure on lung cancer occurrence in women were selected. Estimate of summary effect size (sES) with 95% confidence intervals (CIs) were calculated. Results: A total of 14 cohort studies were finally selected. A random effect model was applied due to heterogeneity (I-squared, 64.3%). The sES of the 14 articles evaluating the impact of HRT exposure on lung cancer occurrence in women indicated no statistically significant increase in lung cancer risk (sES, 0.99; 95% CI, 0.90 to 1.09). Conclusions: These results showed that HRT history had no effect on the risk of lung cancer in women, even though the sES of case-control studies described in previous SR articles indicated that HRT had a protective effect against lung cancer. It is necessary to conduct a pooled analysis of cohort studies.

• Child Health Nursing Research
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• v.13 no.2
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• pp.212-221
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• 2007

Background: Adolescent risk behaviors are of concern because they are dangerous in themselves and have negative influences on adult health. Objectives: This study explored six health risk behaviors of a sample representing the adolescent population in Jeju. Methods: Frequency and percentage of risk behaviors were calculated. Additionally, the chi-square test was used to explore whether differences in experimentation with risk behaviors exist relative to gender and schooling levels. Results: There were six major findings in this study: (a) a lower rate of lifetime and current cigarette use among female students compared to male students, (b) a substantial portion of heavy drinkers, (c) a higher rate of lifetime drug use among female students than among male students, (d) a higher prevalence of suicide ideation among female students than among male students, (e) substantial percentages of students who did not usually wear seatbelts, motorcycle helmets, or bicycle helmets, and (f) a substantial portion of students who were not involved in vigorous physical activities. Conclusions: Since a substantial portion of adolescents have been involved with diverse risk behaviors, it is urgent to implement effective intervention strategies to reduce the rates of these behaviors.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.5
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• pp.2323-2328
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• 2014

Background: Epidemiological findings are controversial relating to the relationship between dietary folate intake and the risk of breast cancer. We therefore conducted a meta-analysis of prospective cohort studies to clarify this association. Materials and Methods: PUBMED, EMBASE, and MEDLINE databases were searched for all relevant literature published in English from January 1, 1966 to August 2013. Summary relative risk (RR) and 95% confidence intervals (CIs) were calculated using a fixed or random effects model. Results: Dietary folate intake was not significantly associated with the risk of breast cancer. The combined RR with 95%CI for the highest vs. lowest category dietary intake of folate [fifteen studies; 1,836,566 participants and 24,083 patients with breast cancer] was 0.98 (0.90-1.05). Among subgroup analysis by menstrual status, hormonal status and the consumption of alcohol, methionine and vitamin B12, no significant association was observed for the dietary intake of folate and the risk of breast cancer. Dose-response analysis showed that a 220 ${\mu}g/day$ increment in dietary folate intake was not associated with the risk of breast cancer. Conclusions: Our findings indicate that dietary folate intake has no significant effect on the risk of breast cancer.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.9
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• pp.4677-4681
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• 2012

Objective: Egg consumption has been suggested to increase the risk of colorectal and some other cancers. The present study summarized and quantified the current evidence relating dietary intake of eggs and prostate cancer. Materials and methods: Literature searches were conducted to identify peer-reviewed manuscripts published up to July 2012. Twenty manuscripts from nine cohort studies and 11 case-control studies were identified. Summary risk estimates with 95% confidence intervals (CIs) were calculated for case-control and cohort studies separately. Results: Neither the case-control not the cohort studies showed any association of prostate cancer incidence with egg consumption (case-control studies: odds ratio 1.09, 95% CI 0.86-1.31; cohort studies: relative risk 0.97, 95% CI 0.97-1.07). The results were consistent in subgroup analysis. Furthermore, no association was observed between egg consumption and prostate cancer-specific mortality. Conclusions: Our analyses provided no evidence of a significant influence of egg consumption on prostate cancer incidence and mortality. However, more studies, particularly large prospective studies, are needed.

• Environmental Engineering Research
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• v.13 no.2
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• pp.73-78
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• 2008

For a given soil-contaminated site, a level of soil contamination is characterized and decisions on risk may be made from the risk assessment. The study evaluated critical design factors for the determination of sample size in the sampling design plan and the assessment of soil contaminant- leaching to groundwater. Two variables, the minimum relative detectable difference (T) and coefficient of variation (CV) were evaluated for the sample size determination. The minimum number of samples can be appropriately determined by CV under a T value greater than or equal to 0.2. Soil-contaminant leaching to groundwater was evaluated by using the Soil Screening Level equation of U.S. Environmental Protection Agency and the Risk Based Screening Level equation of American Society for Testing and Materials, with the same input parameters. The groundwater concentrations estimated from soil contaminant concentrations were significantly affected by the Darcy velocity of groundwater and the organic content of soil.

• Journal of the Korean Data and Information Science Society
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• v.19 no.3
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• pp.831-844
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• 2008

Since cooperatives consist of many distinct members in the management environment and characteristics, it is necessary to make similar cooperatives into a few groups for the effective risk management of cooperatives' mutuality bank. This paper is a priori research for suggesting a guidance for effective risk management of cooperatives with different management strategy. For such purpose, we propose a way to group the members of cooperative's mutuality bank. The 30 continuous variables which is relative to cooperatives' management status are considered and six factors are extracted from those variables through factor analysis with empirical consideration to avoid wrong grouping and to enhance the practical interpretation. Based on extracted six factors and additional 3 categorical variables, six representative groups are derived by the two step clustering analysis. These findings are useful to execute a discriminatory risk management and other management strategy for a mutuality bank and others.

• Journal of the Ergonomics Society of Korea
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• v.29 no.5
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• pp.811-818
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• 2010

In this study, a self-administered checklist for evaluation of the musculoskeletal disorders risk factors in construction industry was developed, and its reliability and validity were studied. 10 items of the checklist were determined based on the literature review, and total 2,793 construction workers participated in the analysis of the checklist's applicability. The results from the reliability analysis showed high Cohen's kappa coefficient (0.50~0.77), and high validity was also obtained in terms of relative risk (RR 1.73~9.14). Positive predictability was relatively low (13.0~32.5%), while negative predictability was high (80.1~96.8%). It can be concluded that the checklist would be suitable as a quick filtering tool of the ergonomic risk factors.