• 한국재난정보학회 논문집
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• 제8권3호
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• pp.234-241
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• 2012

본 연구의 주 목적은 다층 구조를 가진 아스팔트 포장체의 피로균열에 대한 공용성 예측모델을 검정하는 것이다. 그러나, 검정 인자는 목표로 하는 예측모델, 시험법 및 시험중 하중이력에 따라 차이가 있을 수 있다. 본 연구에서 수행된 다양한 현장 조사에 의하면, 연성포장의 피로공용성은 교통하중뿐만 아니라 포장체의 완성후 경과기간에 영향을 받는 것으로 나타났다. 이에 따른 각각의 교통하중과 경과기간에 대한 가중치가 본 연구에서 제시되었다. 또한, 기 발표된 피로 예측모델을 바탕으로 실내와 현장조사를 통하여 얻어진 피로균열 데이터의 상호 상관관계를 분석하여 피로 예측모델에 대한 검정 인자가 개발되었다.

• 한국자동차공학회논문집
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• 제10권1호
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• pp.45-50
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• 2002

Use of a phenomenological model, developed far prediction of catalytic deactivation, is demonstrated in comparing harshness of different driving cycles that are currently used to rapidly age catalytic converters on engine test benches. The model shows that seemingly equivalent driving cycles cause the catalytic converters to reach significantly different levels of deactivation. The comparison of the model prediction with the limited vehicle data seems encouraging despite the simplicity of the model at the current stage of its infancy.

• 대한한방소아과학회지
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• 제31권4호
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• pp.31-38
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• 2017

Objectives The purpose of this study was to find out the clinically reliable relationships between the Risser sign and chronological age, bone age, menarche, and adult height prediction (AHP) and to evidence the reliability of the Risser sign. Methods This study had been carried out with 50 children who had their growth checked in an oriental medical hospital from January 2015 to February 2017. We investigated Risser sign in AP X-rays with iliac crest, bone age, AHP for all 50 children and the timing of menarche from the 22 girls in the study subjects. We also investigated a correlation between the Risser stage and the other indicators to analyze statistical data. Results The mean chronological ages of Risser 1, 2, 3 and 4 were 11.2, 12.6, 14.4, and 15.5 years respectively for the boys and 10.8, 12.2, 13.8 and 14.8 years respectively for the girls. The mean bone ages of Risser 1, 2, 3 and 4 were 12.3, 13.6, 15.7 and 16.5 years respectively for the boys and 11.7, 13.8, 14.3 and 14.9 years respectively for the girls. We analyzed 22 girls' Risser stages in accordance with the duration from menarche. The result showed that in the first six months after menarche, all girls were in Risser 1 and 2; in the next six months, the girls were in Risser 2 on average; in the next 12 months, all girls were in Risser 3 and 4; after more than two years from menarche, all girls were in Risser 4. The mean remaining growth height of Risser 1, 2, 3 and 4 were 27.8, 17.3, 4.4 and 1.0 cm respectively for the boys and 14.5, 5.1, 3.1 and 1.1 cm respectively for the girls. The Risser stage was correlated strongly with chronological age (Spearman's rho=0.707 (boy), 0.841 (girl)), bone age (Spearman's rho=0.869 (boy), 0.875 (girl)), duration from menarche (Spearman's rho=0.909) and remaining growth height (Spearman's rho=-0.784 (boy), -0.878 (girl)). Conclusions This study showed that the Risser sign can be useful in assessing skeletal maturity and predicting remaining growth height based on the Risser stage and the other growth indicators.

• International Journal of Industrial Entomology and Biomaterials
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• 제6권2호
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• pp.163-169
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• 2003

Studies were conducted on the effect of pruning time, host age, conidial dispersal and weather parameters on the incidence and severity of mulberry leaf spot (Myrothecium roridum). The disease severity (%) increased with increase in shoot age irrespective of pruning date. Maximum disease severity was observed in plants pruned during first week of April and minimum disease severity in plants pruned during first week of March. Significant (P ＜ 0.01) influence of date of pruning, shoot age and their interaction was observed on severity of the disease. Apparent infection rate (r) was significantly higher during the plant growth period from day 48 to day 55. Average apparent yale was higher in plants pruned during first week of April and least in plants pruned during first week of July. The disease infection was negatively correlated to distance from the inoculum source. Leaf spot severity (%) was influenced by weather parameters. Multiple regression analysis revealed contribution of various combinations of weather parameters on the disease severity. Linear prediction model $(Y ＝ －81.803＋1.176x_2＋0.765x_3) with significant $R^2$ was developed for prediction of the disease under natural epiphytotic condition.

• International Journal of Industrial Entomology and Biomaterials
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• 제22권1호
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• pp.11-15
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• 2011

Impact of pruning date, shoot age and weather parameters on the severity and development of grey leaf spot (Pseudocercospora mori) of mulberry was studied. The disease severity (%) increased with increase in shoot age irrespective of pruning date. Maximum disease severity was observed in plants pruned during second week of October and minimum in plants pruned during last week of December. Significant (P<0.05) influence of date of pruning, shoot age and their interaction was observed on the severity of the disease. Apparent infection rate (r) was significantly higher during plant growth period from day-48 to day-55. Average apparent rate was higher in plants pruned during first week of September and least in plants pruned during third and fourth week of December. Multiple regression analysis revealed contribution of various combinations of weather parameters on the disease severity. A linear prediction model [$Y=66.05+(-1.39)x_1+(-0.219)x_4$] with significant $R^2$ was developed for prediction of the disease under natural epiphytotic condition.

• 한국전문물리치료학회지
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• 제16권3호
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• pp.60-68
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• 2009

Psychsocial factors appear to play an important role in the maintenance and development of chronic disability from low back pain. Fear of pain may be more disabling than the pain itself in patients with nonacute low back pain. The purpose of this study was to identify the contribution of gender, age, depression and pain-related fear to pain intensity and disability in nonacute low back pain patients. This was a cross-sectional survey study of eighty four patients who had low back pain for at least 4 weeks. More than moderate correlations were found between pain intensity, disability, fear-avoidance beliefs and depression. Regression analyses revealed that disability ratings and fear-avoidance beliefs for work activities significantly contributed to the prediction of pain intensity, even when controlling for age, gender and pain duration. Also, fear-avoidance beliefs for physical activity, pain intensity, age and depression, significantly contributed to the prediction of disability, even when controlling for gender and pain duration. These findings suggest that disability scores and fear-avoidance beliefs for work activities are important determinants of pain intensity. They also suggest that fear-avoidance beliefs for physical activity, pain intensity, age and depression are important determinants of disability.

• 대한예방의학회:학술대회논문집
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• 대한예방의학회 1996년도 제48차 추계 학술대회 연제집
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• pp.119-120
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• 1996

• Tuberculosis and Respiratory Diseases
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• 제45권3호
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• pp.536-545
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• 1998

연구배경: 우리나라의 노력성 호기곡선을 이용한 폐활량측정법 검사지표들의 추정정상치에 관한 연구는 청년과 중년층이 대부분인 집단을 대상으로 이루어져 실제 폐기능검사를 많이 하는 고령인구를 거의 포함하고 있지 않다. 이에 저자들은 일부 농촌지역 50세 이상 건강인군에서 폐활량측정법 검사지표들의 추정정상치 산출 공식을 구하고 이들 기존의 연구들과 비교하여 고연령층에서 적정한 폐활량측정법 검사지표들의 추정정상치를 살펴보고자 했다. 방 법: 일부 농촌지역 50세 이상 성인 533명(남자 215명, 여자 318명)을 대상으로 적절한 폐기능검사를 행했으며 담배를 피지 않으며 만성기침, 가래, 천명 등의 호흡이 증상과 심폐질환의 과거력, 척추와 흉곽의 변형 등 호흡기계에 영향을 끼치는 항목을 갖지 않는 건강인군 남자 32명, 여자 110명을 선정하였다. 이들로부터 노력성 호기곡선을 이용한 폐활량측정법 검사지표들의 추정정상치를 위한 회귀방정식을 구하고 다른 연구의 회귀방정식과 비교해 보았다. 결 과: 남녀 모두에서 FVC는 나이와 음의 상관관계를, 키와는 양의 상관관계를 나타냈다. $FEV_1$은 여자에서는 나이와 음의 상관관계를, 키와는 양의 상관관계를 나타냈으나 남자에서는 키 대신 몸무게가 양의 상관관계를 나타냈다. 남녀 모두에서 FEVl%와 유의한 상관을 보이는 변수는 없었다. 본 연구의 평균 나이, 키, 몸무게을 넣어 구한 추정정상치를 비교해보면 남자에서는 본연구의 FVC, FEV1 값이 다른 연구의 추정치에 비해 매우 낮은 값을 보이고 있으나 여자의 FVC, FEV1 값은 미국에서 고령의 흑인을 대상으로한 연구와 각각 비슷하거나 약간 높은값을 보였다. 결 론: 일부 농촌에서 50세 이상 건강인군에서 나이, 키, 몸무게를 독립변수로 한 노력성호기곡선을 이용한 폐활량측정법 검사지표들의 추정정상치를 산출하는 회귀방정식을 구하였다. 본 연구의 추정정상치들은 기존의 국내 연구에서의 추정정상치에 비해 낮은 값을 보이고 있다. 고령층 인구집단을 대상으로 ATS의 권고 기준에 합당한 폐활량 측정법 검사지표들의 추정 정상치를 구하는 연구들이 앞으로 더 필요하리라 생각된다.

• 대한간호학회지
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• 제50권2호
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• pp.191-199
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• 2020

Purpose: The purpose of this study was to compare sociodemographic characteristics of a normal cognitive group and mild cognitive impairment group, and establish prediction models of Mild Cognitive Impairment (MCI). Methods: This study was a secondary data analysis research using data from "the 4th Korea Longitudinal Study of Ageing" of the Korea Employment Information Service. A total of 6,405 individuals, including 1,329 individuals with MCI and 5,076 individuals with normal cognitive abilities, were part of the study. Based on the panel survey items, the research used 28 variables. The methods of analysis included a χ²-test, logistic regression analysis, decision tree analysis, predicted error rate, and an ROC curve calculated using SPSS 23.0 and SAS 13.2. Results: In the MCI group, the mean age was 71.4 and 65.8% of the participants was women. There were statistically significant differences in gender, age, and education in both groups. Predictors of MCI determined by using a logistic regression analysis were gender, age, education, instrumental activity of daily living (IADL), perceived health status, participation group, cultural activities, and life satisfaction. Decision tree analysis of predictors of MCI identified education, age, life satisfaction, and IADL as predictors. Conclusion: The accuracy of logistic regression model for MCI is slightly higher than that of decision tree model. The implementation of the prediction model for MCI established in this study may be utilized to identify middle-aged and elderly people with risks of MCI. Therefore, this study may contribute to the prevention and reduction of dementia.

• Journal of Preventive Medicine and Public Health
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• 제53권5호
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• pp.313-322
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• 2020

Objectives: This study was conducted to determine the incidence and risk factors of myocardial infarction (MI) and stroke in farmers compared to the general population and to establish 5-year prediction models. Methods: The farmer cohort and the control cohort were generated using the customized database of the National Health Insurance Service of Korea database and the National Sample Cohort, respectively. The participants were followed from the day of the index general health examination until the events of MI, stroke, or death (up to 5 years). Results: In total, 734 744 participants from the farmer cohort and 238 311 from the control cohort aged between 40 and 70 were included. The age-adjusted incidence of MI was 0.766 and 0.585 per 1000 person-years in the farmer and control cohorts, respectively. That of stroke was 0.559 and 0.321 per 1000 person-years in both cohorts, respectively. In farmers, the risk factors for MI included male sex, age, personal history of hypertension, diabetes, current smoking, creatinine, metabolic syndrome components (blood pressure, triglycerides, and high-density lipoprotein cholesterol). Those for stroke included male sex, age, personal history of hypertension, diabetes, current smoking, high γ-glutamyl transferase, and metabolic syndrome components (blood pressure, triglycerides, and high-density lipoprotein cholesterol). The prediction model showed an area under the receiver operating characteristic curve of 0.735 and 0.760 for MI and stroke, respectively, in the farmer cohort. Conclusions: Farmers had a higher age-adjusted incidence of MI and stroke. They also showed distinct patterns in cardiovascular risk factors compared to the general population.