• 대한수학회보
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• 제40권4호
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• pp.663-669
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• 2003

This paper investigates the tail asymptotic behavior of the severity of ruin (the deficit at ruin) in the renewal model. Under the assumption that the tail probability of the claimsize is dominatedly varying, a uniform asymptotic formula for the tail probability of the deficit at ruin is obtained.

• 한국학교보건학회지
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• 제14권2호
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• pp.215-225
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• 2001

The purpose of this study was to identify factors related to High School Students' Attitudes(prejudice) toward HIV-infected classmates. 980 self-administrated questions were completed by high school male students. Stepwise Multiple Regression Analysis was performed with the following independent variables: knowledge about HIV/AIDS transmission, prevention, and HIV-antibody, interests, preventive behaviors, predicting level to peer HIV-related risk behavior, knowledge about information sites, perceived susceptibility, perceived severity, self-efficacy to prevention, related to AIDS/HIV, thought about premarital sexual behavior and homosexuality. The Regression Model is significant(R2=.1719, F=33.517, p<0.05) The significant factors are knowledge about HIV/AIDS transmission, intention of the preventive behaviors, knowledge of information sites, perceived severity, ideas about homosexuality, predicting level of peer HIV-related risk behavior. The results of this study provide information for effective education program development and health policy about AIDS prevention and management.

• 상하수도학회지
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• 제27권6호
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• pp.731-741
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• 2013

CCTV inspection method has been used in Korea for more than 20 years, but there is no proper assessment system for sewer failure severity that considers the domestic circumstances. This study classified the defects caused by the overburden load of reinforced concrete sewer pipes depending on severity and developed defect code by analyzing the domestic CCTV inspection videos. The defect score was assigned to each defect code, and it was classified into 5 grades for the decision-making of repair and rehabilitation. The result of this study is expected to be useful for domestic CCTV inspectors to assess the sewer condition and helpful for managers to make a decision of repair and rehabilitation.

• 한국도로학회논문집
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• 제14권5호
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• pp.101-111
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• 2012

PURPOSES: Because expressway ramps are very complex segments where diverse roadway design elements dynamically change within relatively short length, drivers on ramps are required to drive their cars carefully for safety. Especially, ramps on expressways are designed to guarantee driving at high speed so that the risk and severity of traffic accidents on expressway ramps may be higher and more deadly than other facilities on expressways. Safe deceleration maneuvers are required on off-ramps, whereas safe acceleration maneuvers are necessary on onramps. This difference in required maneuvers may contribute to dissimilar patterns and severity of traffic accidents by ramp types. Therefore, this study was aimed at developing prediction models of the severity of traffic accidents on expressway on- and off-ramps separately in order to consider dissimilar patterns and severity of traffic accidents according to types of ramps. METHODS: Four-year-long traffic accident data between 2007 and 2010 were utilized to distinguish contributing design elements in conjunction with AADT and ramp length. The prediction models were built using the negative binomial regression model consisting of the severity of traffic accident as a dependent variable and contributing design elements as in independent variables. RESULTS: The developed regression models were evaluated using the traffic accident data of the ramps which was not used in building the models by comparing actual and estimated severity of traffic accidents. Conclusively, the average prediction error rates of on-ramps and offramps were 30.5% and 30.8% respectively. CONCLUSIONS: The prediction models for the severity of traffic accidents on expressway on- and off-ramps will be useful in enhancing the safety on expressway ramps as well as developing design guidelines for expressway ramps.

• 한국환경복원기술학회지
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• 제12권5호
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• pp.28-41
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• 2009

Because fire has significant impacts on fauna and flora in forest ecosystems, as well as socioeconomic influences to local community, it has been an important field of study for decades. One of the most common ways to reduce fire risk is to enhance fire-resilience of forest through fuel treatments including thinning and prescribed burning. Since fuel treatment can't be practiced over all forested areas, appropriate and effective strategies are needed. The present study aims to look at the relationship between spatial characteristics of forest structure measured with landscape pattern metrics and burn severity to provide guidelines for effective fuel treatments. Samchuck fire was selected for the study, and 232 grids covering the study areas were generated, and the grid size was 1km. The burn severity is measured with dNBR derived from satellite imagery, and spatial characteristics of forest structure were measured using FRAGSTATS for both landscape and class levels for each 1km grid. The results of this study strongly indicated that heterogeneity in composition and configuration of forests may significantly reduce burn severity. By enhancing heterogeneity of forests, fuel treatments for fire-resilience forest could be more effective.

• 대한간호학회지
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• 제35권3호
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• pp.469-477
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• 2005

Purpose: This study was conducted to investigate the factors that affect the severity of urinary incontinence and the quality of life of women with urinary incontinence. Methods: An exploratory correlation research design was applied and the sixty women who responded that they currently experience involuntary urine leakage at least once per week were invited to participate in the study. Results: According to the study results, the factors that significantly contribute to the severity of urinary incontinence were age, number of parity, and number of normal deliveries. Other influencing factors, such as obesity, menopausal state, hysterectomy, and number of episiotomies, were not significant to predict the severity of urinary incontinence. Urinary incontinence frequency per week and duration of experiencing urinary incontinence were shown to be factors that significantly affect quality of life. Conclusion: In women above 60 years old, multiparity, and multiple experiences of vaginal delivery tended to present a higher level of severity of urinary incontinence. In addition, women with higher frequencies of urinary incontinence per week and a longer duration of urinary incontinence showed a lower level of quality of life.

• 한국식품영양학회지
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• 제18권3호
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• pp.229-240
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• 2005

This quantitative study was investigated to examine the relationship between severity of state-trait anxiety and disordered eating patterns in some university students. This study used a cross-sectional study design. Total 347 students participated in this study (88 male and 259 female) among three universities. The assessment of eating disorder was conducted by Eating Attitudes Test (EAT-26), a score of >or=20 identified individuals likely to have an eating disorder, including anorexia nervosa and bulimia nervosa. Scores of healthy dietary behaviors were obtained by self-assessment instrument on healthy diet scale(20-item questionnaire), and severity of state-trait anxiety was calculated by state-trait anxiety inventory(Total 40- item questionnaire). In groups for each state anxiety and trait anxiety, there were divided between 50 percentile point of cumulatived scores of state anxiety and trait anxiety in all subjects. Linear regression analysis showed overall significant difference between dietary patterns(anorexia nervosa and healthy dietary behaviors) and severity of state-trait anxiety in all sex. Our results indicated that severity of state-trait anxiety may marked eating disorder symptomatology on dimensions of eating disorder prevention.

• 한국안전학회지
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• 제37권1호
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• pp.78-87
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• 2022

In the risk assessment of urban railway systems, a hazard log is created by identifying hazards from accident and failure data. Then, based on a risk matrix, evaluators analyze the frequency and severity of the occurrence of the hazards, conduct the risk assessment, and then establish safety measures for the risk factors prior to risk control. However, because subjective judgments based on the evaluators' experiences affect the risk assessment results, a more objective and automated risk assessment system must be established. In this study, we propose a risk assessment model in which an adaptive neuro-fuzzy inference system (ANFIS), which is combined in artificial neural networks (ANN) and fuzzy inference system (FIS), is applied to the risk assessment of urban railway systems. The newly proposed model is more objective and automated, alleviating the limitations of risk assessments that use a risk matrix. In addition, the reliability of the model was verified by comparing the risk assessment results and risk control priorities between the newly proposed ANFIS-based risk assessment model and the risk assessment using a risk matrix. Results of the comparison indicate that a high level of accuracy was demonstrated in the risk assessment results of the proposed model, and uncertainty and subjectivity were mitigated in the risk control priority.

• 한국안전학회지
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• 제35권1호
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• pp.12-17
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• 2020

This paper analyzes functions of component parts of D-Urban Railway's door system along with operation obstacle risks on frequency(the number of occurrences/year) and severity(delay time/the number of occurrences). Based on this, the paper presents improvements and current system's problems after obstacle risks of EMU and door system are appled. The obstacle of door system causes corrosion of main parts such as DCU due to heat problem of operation environment, problems of maintenance methods and deterioration. DCUs on PCBs with more than 50% pattern corrosion cause problems. Even though the number of door system's obstacle occurrences for the last 5 years is 42, along with 104 minutes of operation obstacle, EMU operation obstacle risk is low(Level 1), which indicates there is limit in matrix of railway risks presented by the standard of railway safety management system. Therefore, it is necessary to have railway risk matrix suitable for the field. Finally, the paper deducts the obstacle risks through frequency and severity. Since 2017 when the risks of EMU and door system's obstacle, that of EMU has been 24(47% reduced) and that of door system has been average 9.5 per year(23% reduced).

• 한국의료질향상학회지
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• 제10권2호
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• pp.216-231
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• 2003

Objectives: To develop a model that predicts a death probability of acute myocardial infarction(AMI) patient, and to evaluate a performance of hospital services using the developed model. Methods: Medical records of 861 AMI patients in 7 general hospitals during 1996 and 1997 were reviewed by two trained nurses. Variables studied were risk factors which were measured in terms of severity measures. A risk model was developed by using the logistic regression, and its performance was evaluated using cross-validation and bootstrap techniques. The statistical prediction capability of the model was assessed by using c-statistic, $R^2$ as well as Hosmer-Lemeshow statistic. The model performance was also evaluated using severity-adjusted mortalities of hospitals. Results: Variables included in the model building are age, sex, ejection fraction, systolic BP, congestive heart failure at admission, cardiac arrest, EKG ischemia, arrhythmia, left anterior descending artery occlusion, verbal response within 48 hours after admission, acute neurological change within 48 hours after admission, and 3 interaction terms. The c statistics and $R^2$ were 0.887 and 0.2676. The Hosmer-Lemeshow statistic was 6.3355 (p-value=0.6067). Among 7 hospitals evaluated by the model, two hospitals showed significantly higher mortality rates, while other two hospitals had significantly lower mortality rates, than the average mortality rate of all hospitals. The remaining hospitals did not show any significant difference. Conclusion: The comparison of the qualities of hospital service using risk-adjusted mortality rates indicated significant difference among them. We therefore conclude that risk-adjusted mortality rate of AMI patients can be used as an indicator for evaluating hospital performance in Korea.