• Journal of Oriental Neuropsychiatry
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• v.19 no.2
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• pp.133-139
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• 2008

Objective : The purpose of this research was to investigate the prevalence rate of Hwa-Byung for the whole population in a local community. Method : Hwa-Byung Diagnostic Interview Schedule(HBDIS) was carried out for 671 participants in Wonju Cohort study. HBDIS is objective questionnaire for diagnose Hwa-Byung. Collected data was analyzed by the chi-square test. Result: Prevalence rate of Hwa-Byung was 5.4% in the whole population. Prevalence rate of Hwa-Byung in male participants was 2.5%, 1.5% in 40s, 3.2% in 50s, 2.5% in 60s. Prevalence rate of Hwa-Byung in female participants was 7.4%, 7.6% in 40s, 5.5% in 50s, 8.7% in 60s. Conclusion : There was significant difference on the prevalence rate of Hwa-Byung according to sex.

• Journal of Home Health Care Nursing
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• v.20 no.2
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• pp.133-140
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• 2013

Purpose: This study examined the demographic and lifestyle differences between women with osteopenia and those with normal bone mineral density (BMD) to identify risk factors for osteopenia. Method: Participants comprised 381 women age 40-64 years. Data were collected using surveys, BMD measures, and anthropometric parameters. Results: Prevalence of osteopenia was 29.1%; significant differences in age group, job, age at menarche, age at menopause, and body mass index were found between women with osteopenia and those with normal BMD. Logistic regression analysis indicated that advanced age, unemployment, lower body mass index, and lack of exercise in women were significantly associated with osteopenia. Conclusion: This study suggests the need for strategies to improve bone health and continuous cohort studies to identify risk factors.

• Korean System Dynamics Review
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• v.11 no.1
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• pp.27-57
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• 2010

This article deals with an ecological-economic analysis of the 'Pasture Project of Kum River', which is the farming plan of mitten crabs using Jichun, a stream of the River Kum where the natural propagation of mitten crabs are blocked because of the estuary dam constructed in 1990. Toward analyzing the ecological and economic effects of the crab releasing and harvesting activities in Jichun, a two-stage cohort model of population dynamics with cannibalistic behaviors and density restrictions in biomathematics is adopted, despite of the current infertility in Kum, considering the opportunity of establishing dam fishways in the near future. This study moreover presents a method of parameter estimation especially with assuming a steady state of the ecosystem, and performs various analyses such as the risk measurement of climate change and the economic value of such fishways.

• Journal of Korean Dental Science
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• v.3 no.2
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• pp.34-39
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• 2010

In our daily practice, we think about the diagnosis of our patient and get into a situation wherein we have to make a clinical decision. Diagnosis and treatment come from the knowledge and experiences that each dentist should have, but sometimes, we can have doubts on our decisions. "On what evidence did I make such decision? Was that really right?" Drawing our attention these days as a possible answer to this question, evidence-based dentistry seeks to apply the best available evidence gained from the scientific method to medical decision making. To make a good decision, the strength of evidence is assessed. Specifically, randomized controlled trial, systematic review, and meta-analysis are considered the highest level of evidence; cohort study, case control study, case series, animal study, bench test, and biological plausibility follow. With the approach of evidence-based dentistry, we can make objective, scientifically sound clinical decisions. It is also patient-oriented, incorporating clinical experiences and stressing good judgments; thorough and comprehensive, it uses transparent methodology. That is the reason evidence-based dentistry can be better than other assessment methods when we make a clinical decision in modern dentistry.

• Communications for Statistical Applications and Methods
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• v.23 no.6
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• pp.555-562
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• 2016

Interval censored data often occur in an observational study where the subject is followed periodically. Instead of observing an exact failure time, two inspection times that include it are available. There are several methods to analyze interval censored failure time data (Sun, 2006). However, in the presence of competing risks, few methods have been suggested to estimate covariate effect on interval censored competing risk data. A sub-distribution hazard model is a commonly used regression model because it has one-to-one correspondence with a cumulative incidence function. Alternatively, Klein and Andersen (2005) proposed a pseudo-value approach that directly uses the cumulative incidence function. In this paper, we consider an extension of the pseudo-value approach into the interval censored data to estimate regression coefficients. The pseudo-values generated from the estimated cumulative incidence function then become response variables in a generalized estimating equation. Simulation studies show that the suggested method performs well in several situations and an HIV-AIDS cohort study is analyzed as a real data example.

• Proceedings of the Korean Information Science Society Conference
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• 2004.04b
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• pp.571-573
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• 2004

Speaker verification systems based on multilayer perceptrons (MLPs) have good prospects in reliability and flexibility required as a successful authentication system. However, the poor learning speed of the error backpropagation (EBP) which is representative learning method of MLPs is the major defect to be complemented to achieve real-time user enrollments. In this paper, we implement an MLP-based speaker verification system and apply the existing two methods of the omitting patterns in instant learning (OIL) and the discriminative cohort speakers (DCS) to approach real-time enrollment. An evaluation of the system on a Korean speech database demonstrates the feasibility of the system as a speaker verification system of high performance.

• The Korean Journal of Applied Statistics
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• v.19 no.3
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• pp.395-406
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• 2006

Long-term survival rates are the most commonly used outcome measures for patients with cancer. However, traditional long-term survival statistics, which are derived by cohort analysis or complete analysis, essentially reflect the survival expectations of patients diagnosed many years ago. They are often outdated at the time they become available. In this article, we propose a modified product-limit method to obtain up-to-date estimates of long-term survival rates via a period analysis. The proposed method is illustrated with cancer registry data collected from January 1993 to December 1997.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.2
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• pp.163-173
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• 1995

Populations of the common squid, Todarodes pacifirus in the Korean waters were analyzed using the samples taken monthly from February, 1991 to July, 1992. Summer, Autumn and Winter cohorts were arbitrarily established based on frequency distributions of mantle lengths and maturation stages. As cohorts were seperated in mantle length distributions on the basis of accumulated information of size and maturation of T. pacificus, cohorts seperated by the present method were mostly in accord with those by Tanaka's method. But they were not consistent with those by Bhattacharya's and Cassie's methods.

• Journal of the Korean Data and Information Science Society
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• v.22 no.6
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• pp.1167-1173
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• 2011

The goal of this paper is to suggest an algorithm to get forecasting for the numbers of students in the city or county in local government by using the double exponential smoothing method. By 2044 year, the third year of high school students in the Chilgok, Gumi, Gyeongsan, Andong, Pohang and Gimchen are reduced about 40-70%, the those of in the remaining city or county are reduced about 70-95%. In conclusion, the forecasting numbers of students of the 23 counties in Kyungbuk Province are on the decrease to 40%-100% until 2044 year in comparison with the numbers of students on 2010 years.

• Environmental Analysis Health and Toxicology
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• v.29
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• pp.12.1-12.8
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• 2014

Objectives Cohort studies of associations between air pollution and health have used exposure prediction approaches to estimate individual-level concentrations. A common prediction method used in Korean cohort studies is ordinary kriging. In this study, performance of ordinary kriging models for long-term particulate matter less than or equal to $10{\mu}m$ in diameter ($PM_{10}$) concentrations in seven major Korean cities was investigated with a focus on spatial prediction ability. Methods We obtained hourly $PM_{10}$ data for 2010 at 226 urban-ambient monitoring sites in South Korea and computed annual average $PM_{10}$ concentrations at each site. Given the annual averages, we developed ordinary kriging prediction models for each of the seven major cities and for the entire country by using an exponential covariance reference model and a maximum likelihood estimation method. For model evaluation, cross-validation was performed and mean square error and R-squared ($R^2$) statistics were computed. Results Mean annual average $PM_{10}$ concentrations in the seven major cities ranged between 45.5 and $66.0{\mu}g/m^3$ (standard deviation=2.40 and $9.51{\mu}g/m^3$, respectively). Cross-validated $R^2$ values in Seoul and Busan were 0.31 and 0.23, respectively, whereas the other five cities had $R^2$ values of zero. The national model produced a higher cross-validated $R^2$ (0.36) than those for the city-specific models. Conclusions In general, the ordinary kriging models performed poorly for the seven major cities and the entire country of South Korea, but the model performance was better in the national model. To improve model performance, future studies should examine different prediction approaches that incorporate $PM_{10}$ source characteristics.