• Korean Journal of Health Education and Promotion
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• v.3 no.1
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• pp.113-128
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• 2001

The purpose of this study is to examine the prevalence and correlates of three types of risk-taking behavior among high school students in Korea in a cross-sectional national sample. A sample of 636 male and 622 female high school students is analyzed using descriptive statistics and logistic regression. Three types of risk-taking behavior are examined: drinking alcohol, smoking, and premarital sex. The results are as follows: Forty-three percent of students in the sample have ever drunk alcohol, 32% have ever smoked, 11% have experience premarital sex. Risk-taking behavior is more prevalent among boys than among girls. Boys and girls in Seoul are much more likely to have experienced three types of risk-taking behavior. Not having two parents in the family and having lived away from immediate family increase the likelihood of some risk-taking behavior. Students who have a friend with premarital sexual experience are much more likely to have experienced premarital sex themselves. Among sexually active students, having multiple sexual partners is common and prevalence of condom use is low. Reproductive health education at school has no effect on students' sexual behavior. The prevalence of risk-taking behavior among adolescent in Korea is likely to rise in the future. Substantial proportion of adolescents are exposed to the risks of STDs and substantial proportion of adolescent girls risk premarital pregnancy. Current health education programs are inadequate in protecting students from risk-taking behavior. Students whose families do not include both parents and students who live away from their immediate families need special programs to protect them from risk-taking behavior.

• Journal of Environmental Health Sciences
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• v.39 no.1
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• pp.32-42
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• 2013

Objectives: Cryptosporidium, a protozoan parasite, has been recognized as a frequent cause of waterborne disease due to its extremely strong resistance against chlorine disinfection. Although there has as yet been no report of a Cryptosporidium outbreak through drinking water in Korea, it is important to estimate the health risk of Cryptosporidium in water supply systems because of the various infection cases in human and domestic animals and frequent detection reports on their oocysts in water environments. Methods: This study evaluated the annual infection risk of Cryptosporidium in tap water using the quantitative microbial risk assessment technique. Exposure assessment was performed upon the results of a national survey on Cryptosporidium on the water sources of 97 large-scale water purification plants in Korea, water treatment efficacy, and daily unboiled tap water consumption. The estimates of the US Environmental Protection Agency on the mean likelihood of infection from ingesting one oocyst were applied for effect assessment. Results: Using probabilistic methods, mean annual infection risk of Cryptosporidiosis by the intake of tap water was estimated to fall within the range of $2.3{\times}10^{-4}$ to $1.0{\times}10^{-3}$ (median $5.7{\times}10^{-4}$). The risk in using river sources was predicted to be four times higher than with lake sources. With 0.5-log higher removal efficacy, the risk was estimated to be $1.8{\times}10^{-4}$, and could then be lowered by one-third. Conclusions: These estimations can be compared with acceptable risk and then used to determine the adequacy and priority of various drinking water quality strategies such as the establishment of new treatment technology.

• Journal of Chest Surgery
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• v.57 no.3
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• pp.302-311
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• 2024

Background: Unexpected conversion to thoracotomy during planned video-assisted thoracoscopic surgery (VATS) can lead to poor outcomes and comparatively high morbidity. This study was conducted to assess preoperative risk factors associated with unexpected thoracotomy conversion and to develop a risk scoring model for preoperative use, aimed at identifying patients with an elevated risk of conversion. Methods: A retrospective analysis was conducted of 1,506 patients who underwent surgical resection for non-small cell lung cancer. To evaluate the risk factors, univariate analysis and logistic regression were performed. A risk scoring model was established to predict unexpected thoracotomy conversion during VATS of the lung, based on preoperative factors. To validate the model, an additional cohort of 878 patients was analyzed. Results: Among the potentially significant clinical variables, male sex, previous ipsilateral lung surgery, preoperative detection of calcified lymph nodes, and clinical T stage were identified as independent risk factors for unplanned conversion to thoracotomy. A 6-point risk scoring model was developed to predict conversion based on the assessed risk, with patients categorized into 4 groups. The results indicated an area under the receiver operating characteristic curve of 0.747, with a sensitivity of 80.5%, specificity of 56.4%, positive predictive value of 1.8%, and negative predictive value of 91.0%. When applied to the validation cohort, the model exhibited good predictive accuracy. Conclusion: We successfully developed and validated a risk scoring model for preoperative use that can predict the likelihood of unplanned conversion to thoracotomy during VATS of the lung.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.8
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• pp.4919-4923
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• 2013

Breast cancer is the top cancer in women worldwide and its incidence is increasing, particularly in developing countries. In the United Arab Emirates (UAE), many cases are first diagnosed in later stages and at younger age compared to those seen in developed countries. Early detection in order to improve breast cancer outcome and survival remains the cornerstone of breast cancer control. Performance of breast self examination is one of the important steps for identifying breast disease at an early stage, by the woman herself. No information has hitherto been available about the frequency of this practice among female university students in UAE or about their breast cancer risk perception and therefore the present study was conducted in Ajman. It was found that 22.7% of the participants practiced BSE but only 3% of them practiced BSE monthly. Marital status but not age as significantly associated with age likelihood. The most frequent reported barriers for BSE were lack of knowledge, considering oneself not at risk and the absence of doctor advice. These factors need to be taken into account in intervention efforts.

• Child Health Nursing Research
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• v.29 no.4
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• pp.280-289
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• 2023

Purpose: This study investigated weight status in survivors of childhood acute lymphocytic leukemia (ALL) and identified related factors. Methods: A retrospective review of the electronic medical records of survivors of childhood ALL (n=230) was conducted. We analyzed the survivors' characteristics, including sex, age, weight status at diagnosis, central nervous system involvement, risk classification, length of treatment, radiation therapy, and hematopoietic stem cell transplantation. Analysis of variance and the chi-squared test were applied to investigate influencing factors. Results: The weight status distribution was as follows: 23 individuals (10.0%) were classified as underweight, 151 individuals (65.7%) were healthy weight, and 56 individuals (24.3%) were overweight/obese. Age at diagnosis (F=10.03, p<.001), weight status at diagnosis (x²=43.41, p<.001), and risk classification (F=10.98, p=0.027) showed significant differences among the weight status groups. Survivors who were older at diagnosis and those in the very high-risk category had a higher likelihood of experiencing underweight status during their survivorship, while survivors who were overweight/obese at diagnosis were more likely to remain overweight/obese at the time of survival. Conclusion: Considering the potential health implications related to an unhealthy weight status in survivors of ALL, it is imperative to undertake early identification and implement interventions for at-risk individuals.

• Journal of the military operations research society of Korea
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• v.11 no.2
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• pp.69-82
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• 1985

In this study, we consider the simultaneous estimation of the parameters of the distribution of p independent Poisson random variables using the weighted loss function. The relation between the estimation under the weighted loss function and the case when more than one observation is taken from some population is studied. We derive an estimator which dominates Tsui and Press's estimator when certain conditions hold. We also derive an estimator which dominates the maximum likelihood estimator(MLE) under the various loss function. The risk performances of proposed estimators are compared to that of MLE by computer simulation.

• Journal of applied mathematics & informatics
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• v.6 no.2
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• pp.661-668
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• 1999

Reliability estimation using Gibbs sampler considered for modeling mixture exponential reliability problems. Gibbs sampler is developed to compute the features of the posterior distribution. Bayesian estimation of complicated functions requires simpler esti-mation techniques due to the mathematical difficulties involved in the Bayes approach. The Maximum likelihood estimator and the Gibbs estimator of reliability of the system are derived. By simula-tion risk behaviors of derived estimators are compared. model de-termination based on relative error is considered. A numerical study with a simulated data set is provided.

• Journal of Yeungnam Medical Science
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• v.37 no.4
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• pp.296-301
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• 2020

The geriatric population is at a greater risk of postoperative complications than young adults. This risk is associated with the physiologic decline seen in this population known as frailty. Unlike fitter patients, frail patients who undergo operative treatment have a greater likelihood of developing postoperative complications and endure prolonged hospital stays. This circumstance is comparable to the urological status. Therefore, tolerable measurement of frailty as a domain of preoperative health status has been suggested to ascertain vulnerability in elderly patients. In this review, we will elaborate on the concept of frailty and examine its importance with respect to surgical complications, focusing on the urological status.

• Journal of the Korean Data and Information Science Society
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• v.16 no.3
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• pp.567-580
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• 2005

It is usually assumed that asset returns in the stock market are normally distributed. However, analyses of real data show that the distribution tends to be skewed and to have heavier tails than those of the normal distribution. In this paper, we investigate the method of estimating the value at risk(VaR) of stock returns. The VaR is computed by using the transformation and back-transformation method. The analysis of KOSPI and KOSDAQ data shows that the proposed estimation outperformed that under the normal assumption.

• Management Science and Financial Engineering
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• v.12 no.1
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• pp.65-77
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• 2006

This study proposes a Bayesian dynamic model in a hierarchical way to assess the time-varying effect of risk factors on the likelihood of corporate bankruptcy. For the longitudinal data, we aim to describe dynamically evolving effects of covariates more articulately compared to the Generalized Estimating Equation approach. In the analysis, it is shown that the proposed model outperforms in terms of sensitivity and specificity. Besides, the usefulness of this study can be found from the flexibility in describing the dependence structure among time specific parameters and suitability for assessing the time effect of risk factors.