• Journal of Preventive Medicine and Public Health
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• 제39권3호
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• pp.213-220
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• 2006

Objectives: The purpose of this study was to examine the effect of women's late age of marriage on the interval between marriage and their first birth Methods: Data from Year 2000 Korea National Fertility Survey was collected through direct interview questionings, and the data was analyzed based on randomly selected sampling. In particular, the married women (N=5,648) were analyzed for the factors that determined the first-birth interval by performing Cox's proportional hazard model survival analysis. Results: Unlike previous findings, the woman whose age of marriage was 30 or more was more likely to delay the birth of her first baby than were the other women who married earlier. Further, a woman's age at marriage, a woman's residence before marriage, her husband's religion, her husband's level of education and the difference in age between the woman and her husband significantly influenced the first-birth interval. In contrast, for a married woman, her age, level of education, current residence and religion were not significant predictors of her first birth interval. Conclusions: Our study showed that women who married at the age of 30 years or more tend to postpone their first birth in Korea. When facing the increasing number of women who marry at a late age, the Korean government should implement population and social policies to encourage married women have their first child as early as possible.

• 한국의류산업학회지
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• 제9권3호
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• pp.278-285
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• 2007

The purpose of this study is the image of clothing according to the change of the dots' interval was analyzed and its influence on the formation of the image of polka dots clothing was investigated. White waterdrop patterns were designed on the 12 kinds of black texture using Photoshop and CAD program in regular arrangement of diamond figure, composed of white waterdrop(0.5 cm, 1.0 cm, 1.5 cm and 2 cm in diameter) and interval(diameter : interval - 1 : 1, 1 : 2, 1 : 4). Applying above specification, the photograph stimulus of 12 kinds of X-line one-piece dress with wide square neckline and without sleeve or detailed ornament was presented on a screen in the same size as when putting it on. The image of polka dots clothes was investigated by questionnaire survey. The object of the study was 320 females aged between 16 and 29. Factor analysis, one-way ANOVA, Scheff$\acute{e}$ verication and two-way ANOVA using SPSS 10.0 were carried out for data analysis. The research finding are as follows. First, the image of polka dots clothing consists of 4 factors as aesthetics, brevity, dynamism and lightweight. Secondly, the interval of the dot has a great influence on the formation of the image of polka dots clothing. Lastly, the evaluations of the image of polka dots clothing were different depending on the age and physical image, the personal characteristics of the object of investigation.

• 보건행정학회지
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• 제29권3호
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• pp.357-367
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• 2019

Background: This study evaluated the cost-effectiveness of 21 different national dyslipidemia screening strategies according to total cholesterol (TC) cutoff and screening interval among 40 years or more for the primary prevention of coronary heart disease over a lifetime in Korea, from a societal perspective. Methods: A decision tree was used to estimate disease detection with the 21 different screening strategies, while a Markov model was used to model disease progression until death, quality-adjusted life years (QALYs) and costs from a Korea societal perspective. Results: The results showed that the strategy with TC 200 mg/dL and 4-year interval cost \4,625,446 for 16.65105 QALYs per person and strategy with TC 200 mg/dL and 3-year interval cost \4,691,771 for 16.65164 QALYs compared with \3,061,371 for 16.59877 QALYs for strategy with no screening. The incremental cost-effectiveness ratio of strategy with TC 200 mg/dL and 4-year interval versus strategy with no screening was \29,916,271/QALY. At a Korea willingness-to-pay threshold of \30,500,000/QALY, strategy with TC 200 mg/dL and 4-year interval is cost-effective compared with strategy with no screening. Sensitivity analyses showed that results were robust to reasonable variations in model parameters. Conclusion: In this study, revised national dyslipidemia screening strategy with TC 200 mg/dL and 4-year interval could be a cost-effective option. A better understanding of the Korean dyslipidemia population may be necessary to aid in future efforts to improve dyslipidemia diagnosis and management.

• 대한임상독성학회지
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• 제18권2호
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• pp.130-135
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• 2020

Purpose: Taking large amounts of glyphosate is life-threatening, but the amounts of glyphosate taken by patients for suicide are not known precisely. The purpose of this study was to find the predictors of large amounts of glyphosate ingestion. Methods: This retrospective study analyzed patients presenting to an emergency department with glyphosate intoxication between 2010 and 2019, in a single tertiary hospital. The variables associated with the intake amounts were investigated. The parameters were analyzed by multivariate variate logistic regression analyses and the receiver operating characteristic (ROC) curve. Results: Of the 28 patients with glyphosate intoxication, 15 (53.6%) were in the large amounts group. Univariate analysis showed that metabolic acidosis, lactic acid, and corrected QT (QTc) interval were significant factors. In contrast, multivariate analysis presented the QTc interval as the only independent factor with intoxication from large amounts of glyphosate. (odds ratio, 95% confidence interval: 1.073, 1.011-1.139; p=0.020) The area under the ROC curve of the QTc interval was 0.838. Conclusion: The QTc interval is associated significantly with patients who visit the emergency department after being intoxicated by large amounts of glyphosate. These conclusions will help in the initial triage of patients with glyphosate intoxication.

• Journal of applied mathematics & informatics
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• 제8권1호
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• pp.213-223
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• 2001

The use of fuzzy number over interval of confidence instead of possibilitic consideration for solving fuzzy equation is proposed. This approach of solving fuzzy equation by interval arithmetic and ${\alpha}$-cuts has a considerable advantage. Through theoretical analysis, an illustrative example and computational results, we show that the proposed approach is more general and straight-forword.

• 대한의용생체공학회:의공학회지
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• 제22권2호
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• pp.197-204
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• 2001

• 대한산업공학회지
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• 제42권2호
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• pp.129-137
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• 2016

A colonoscopy is important because it detects the presence of polyps in the colon that can lead to colon cancer. How often one needs to repeat a colonoscopy may depend on various factors. The main purpose of this study is to determine personalized surveillance interval of colonoscopy based on characteristics of patients including their clinical information. The clustering analysis using a partitioning around medoids algorithm was conducted on 625 patients who had a medical examination at Korea University Anam Hospital and found several subgroups of patients. For each cluster, we then performed survival analysis that provides the probability of having polyps according to the number of days until next visit. The results of survival analysis indicated that different survival distributions exist among different patients' groups. We believe that the procedure proposed in this study can provide the patients with personalized medical information about how often they need to repeat a colonoscopy.

• Structural Engineering and Mechanics
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• 제82권3호
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• pp.271-282
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• 2022

The active learning surrogate model based on adaptive sampling strategy is increasingly popular in reliability analysis. However, most of the existing sampling strategies adopt the trial and error method to determine the size of the Monte Carlo (MC) candidate sample pool which satisfies the requirement of variation coefficient of failure probability. It will lead to a reduction in the calculation efficiency of reliability analysis. To avoid this defect, a new method for determining the optimal size of the MC candidate sample pool is proposed, and a new structural reliability analysis method combining polynomial chaos-based Kriging model (PC-Kriging) with adaptive sampling region is also proposed (PCK-ASR). Firstly, based on the lower limit of the confidence interval, a new method for estimating the optimal size of the MC candidate sample pool is proposed. Secondly, based on the upper limit of the confidence interval, an adaptive sampling region strategy similar to the radial centralized sampling method is developed. Then, the k-means++ clustering technique and the learning function LIF are used to complete the adaptive design of experiments (DoE). Finally, the effectiveness and accuracy of the PCK-ASR method are verified by three numerical examples and one practical engineering example.

• 한국지반공학회지:지반
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• 제14권3호
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• pp.95-108
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• 1998

지반의 S파 및 P파의 깊이에 따른 변화를 원위치에서 측정하기 위하여 다운흘 시험 (downhole testing)과 SCPT (seismic CPT) 등이 널리 사용되어 왔다. 다운홀 시험과 SCPT는 경제성, 운용의 용이성, 발진원의 단순성 등의 측면에서 효율적이기 때문에, 현재 지반조사에서 그 사용빈도가 더욱 증가하고 있는 추세이다. 특히 최근에는 다운흘과 SCPT의 자료 분석을 자동화하기 위한 노력의 일환으로 interval measurements의 기법이 활용되고 있는데, 현재 이에 대한 적절한 역산해석 (inversion analysis) 기법이 없는 형편이다. 따라서, 본 논문에서는 다운홀이나 SCPT의 interval measurements를 분석하기 위한 새로운 역산해석 기법을 제안하였다. 제안된 역산해석 기법의 정모델링(forward modeling)에서는 탄성파의 전파를 Snell의 법칙에 의거하여 굴절.반사되는 현상을 고려하였곡, 역산해석을 위해서는 최대공산법 (maximum likelihood method)을 적용하였다. 그리고, 본 논문에서 제안한 역산해석 기법의 검증을 위하여, 하나의 S파 주상도를 가정하고 이에 대하여 다운흘 시험을 모사하였다. 이론적으로 수행한 다운홀 시험 결과에 대하여 기존의 비 역산해석 방법과 본 논문에서 제안한 역산해 석 기법에 의해서 S파 주상도를 추정하였는데, 그 결과 본 논문에서 제시한 역산기법이 가장 정확한 결과를 도출하였으며, 다운홀 시험과 SCPT을 자동화하는데 효율적으로 적용이 될 수 있음을 입증하였다.

• 한국정보통신학회논문지
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• 제15권12호
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• pp.2655-2663
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• 2011

지금까지 심방세동을 검출하는 방법은 P파의 형태, 시간 주파수 영역 분석법이 주를 이루었다. 하지만 P파는 잡음의 영향을 많이 받는 환경에서는 검출의 정확도가 떨어지며, 시간 주파수 영역 분석법은 RR 간격에 따라 변화하는 불규칙적 리듬에 관한 정보를 정확하게 얻지 못하는 단점이 있다. 본 연구에서는, P파의 형태는 고려하지 않고, 불규칙 RR 간격 리듬의 비선형적 특성 분석을 통한 심방세동 검출 알고리즘을 제안한다. 이를 위해 불규칙 RR 간격 리듬을 다양성, 무작위성, 복잡성으로 각각 정의하고 제곱평균제곱근(RMSSD), 전환점비(TPR), 표본 엔트로비(SpEn)의 3가지 비선형적 특성 분석을 통하여 심방세동을 분류하였다. 제안된 알고리즘의 검출 성능을 평가하기 위해 3가지 통계치의 최적값을 설정하고 MIT-BIH 심방세동 데이터베이스와 부정맥 데이터베이스를 이용하여 실험하였다. 성능 평가 결과, MIT-BIH 심방세동 데이터베이스에 대해서는 민감도(sensitivity:94.5%), 특이도(specificity:96.2%)를 각각 나타내었으며, 부정맥 데이터베이스에 대해서는 민감도(89.8%), 특이도(89.62%)를 각각 나타내었다.