• 응용통계연구
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• 제19권1호
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• pp.163-170
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• 2006

역학(epidemiology) 또는 임상(clinic) 자료를 분석하기 위한 주효 측도의 선택에 대한 연구가 계속되고 있지만, 주효 측도들이 일반적인 함수 형태로만 표현되는 경우에는 주효 측도들의 특징이나 관계를 이해하는 것이 쉽지 않다. 이 논문에서는 주효 측도의 선택 문제 보다는 이변량 자료에 대한 주효 측도 중에서 위험도차이(risk different: RD), 상대위험률(relative risk: RR), 그리고 교차비(odds ratio: OR)를 방사형 그림(radar diagram)을 사용하여 나타내고 이 그림을 이용하여 이들의 특성이나 관계를 살펴보았다. 방사형 그림은 이 측도들을 이해하는데 좋은 도구가 될 것이다.

• 기술혁신연구
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• 제6권2호
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• pp.178-207
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• 1998

This article suggests a methodology to decide the priority of investment project for venture business under the dynamic circumstance. By the Monte Carlo procedure on the probability distribution of cost and revenue, the model simulates the investment project to estimate profit ratio and risk. The profit ratio is calculated on the yearly basis for the relative comparison. The project risk is calculated as semi-variance under the target yield. After sufficient simulations in this fashion for several projects, the efficient projects with more profit and less risk are selected by the dominance principle. Then the regression equation of the selected projects is produced to find the relative value of the projects. The relative value is obtained through dividing the raw profit ratio by the estimated one on the equation. This value shows the degree to which the simulated project yields over the equation. The priority of investment is decided by this value. An examplary venture business of chemical development for semi-conductor is presented as a case study.

• 한국환경보건학회지
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• 제32권3호
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• pp.240-248
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• 2006

The purposes of this study were to investigate the symptoms, diseases and deaths of residents living near the municipal solid waste landfill site, and to compare the relative risk ratio of their adverse health effects with control group. In self-evaluation, the scores were especially severe lowest in residents of v2 and v3 villages(which were located about 500 m toward under the landfill site) such as 32.2 and 16.7 for village-environment, 24.8 and 16.0 for management of landfill site, and 23.5 and 16.5 for confidence of environmental policy, respectively. On symptoms, relative risk ratios were also highest as 3.53 and 3.55 for breathing difficulty, and 3.36 and 3.00 for respiratory symptom in v2 and v3 villages, respectively. On morbidity, they were slightly high as much as 1.39 and 1.24 in v5 and v2 villages, respectively. On mortality, relative risk ratios were $1.15{\sim}2.46$ in experimental villages. They were especially high as much as 2.46 in v3 village where located near under the landfill site, and also 2.14 in v5 village where located at area affected with the landfill site, but near the sea. The rate of cancer causing death was average 35.2% of total deaths. It was very highest as much as 61.1 % in v2 village, where was closely located near under the landfill site. Cancers causing death in this village were lung cancer(3 cases), larynx cancer(2 cases), stomach cancer(2 cases), pancreatic cancer(1 case), thryoid cancer(1 case), leukemia(1 case) and other(1 case). Our data, although based on limited number of cases and geographical coverage, suggest that residents living near landfill site have the increasing relative risks of various symptoms and mortality causing cancer. No causal mechanisms are available to explain these findings. But the possibility of a causal association between the increased adverse health effects and the municipal solid waste landfill site cannot be fully excluded.

• Communications for Statistical Applications and Methods
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• 제11권1호
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• pp.181-187
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• 2004

One of objectives in epidemiologic studies is to detect the amount of change caused by a specific risk factor. Risk ratio is one of the most useful measurements in epidemiology. When we perform the inference for this measurement with rare events, the standard approach based on the normal approximation may fail, in particular when there are no disease cases observed. In this paper, we discuss and evaluate several existing methods for constructing a confidence interval of risk ratio through simulation when the disease of interest is a rare event. The results in this paper provide guidance with how to construct interval estimates for risk difference and risk ratio when there are no disease cases observed.

• 대한한의학회지
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• 제24권4호
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• pp.1-5
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• 2003

Leptin has a close correlation with obesity, which is known to be a major factor for stroke. This study was performed to determine whether serum leptin level would be an independent risk factor for stroke and whether it would change significantly early after stroke. Subjects were selected from those within I month after onset and non-stroke referents at Kyung Hee Oriental Medical Center in Seoul, Korea. We compared leptin and the other characteristics between stroke subjects and referents. Body mass index, hypertension history, presence of drinking and smoking, waist/hip ratio, total cholesterol and triglyceride were recorded. To assess odds ratio of leptin for stroke, we used logistic regression analysis. Leptin was rechecked 2 weeks later and compared with the former value in acute stroke subjects. In this study, serum leptin did not differ significantly between stroke subjects and referents, and its odds ratio was not significant in male (OR=0.52, 95％ Cl; 0.13-2.08) and female (OR=1.57, 95％ Cl; 0.53-4.67). In acute stroke subjects, leptin did not change significantly 2 weeks later. Hypertension had a significant odds ratio in male (OR=3.39, 95％ Cl; 1.02-11.24) and female (OR=12.37, 95％ Cl; 3.67-41.65). High waist/hip ratio was only in female (OR=6.70, 95％ Cl; 1.73-26.02). In conclusion, leptin was not an independent risk factor for stroke and its serum level did not change significantly early after stroke. Hypertension and waist/hip ratio had significant relative risks.

• 대한간호학회지
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• 제44권6호
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• pp.743-750
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• 2014

Purpose: The objective of this study was to provide a trend analysis of the prevalence of diabetes relative to the socioeconomic, lifestyle, and physiologic risk factors among Korean adults aged over 30 years for a 10-year period using data from the Korean National Health and Nutrition Examination Survey. Methods: Prevalence difference and the slope index of inequality were calculated for each risk factors using binomial regression by considering the repeated cross-sectional features of the data. The prevalence ratio and the relative index of inequality were calculated using log-binomial regression. Linear trend tests were performed using SAS 9.2. Results: Crude prevalence of diabetes increased over the 10-year period, and was higher for men than for women. It was very high for adults 60 years or over, consistently increasing over time. The prevalence among unemployed men, women with higher level of stress, women with hypertension, and adults with serum triglyceride levels over 135 mg/dL increased over the 10-year period in comparison with the respective control group. Conclusion: Considering the rapid economic development and associated lifestyle changes in Korea, action should be taken to control the prevalence of diabetes by both preventing and consistently monitoring these identified risk factors using a public-health approach.

• 대한토목학회논문집
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• 제39권6호
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• pp.841-851
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• 2019

본 연구는 교차로, 횡단보도, 터널 구간에서 교통사고 유형에 따른 위험 순위를 비교 분석한 것이다. 서울, 경기도에서 발생한 2014년부터 2017년까지의 교통사고자료 중 교통량 및 속도 자료와 결합 가능한 58,868건의 자료를 구축하고, 순서형 로짓모형을 활용하여 사고심각도 추정모형을 구축하였다. 추정된 모형을 기반으로 사고심각도에 영향을 미치는 요인을 규명하고, 영향을 미치는 정도를 살펴보았다. 또한 사고발생위치(교차로, 횡단보도, 터널)별, 사고유형별, 사고발생 시간이나 상황별로 상대적 위험도 분석을 통해 위험순위를 제시하였다. 분석 결과 사고발생 위치와 시간에 따라 사고심각도에 현격한 차이를 보이는 것으로 나타났으며, 분석 자료로부터 산출된 사고 발생 빈도와 사고심각도와 비교해봤을 때, 발생 빈도가 적더라도 사고심각도 측면에서는 위중하거나, 발생 빈도가 높고, 사고심각도 또한 위중한 경우가 존재하는 것으로 분석되었다. 이러한 교통사고유형의 위험 평가를 통해 도로별로 상대적으로 위험한 사고유형에 대한 이해가 가능하고 도로별, 사고유형의 교통사고 위험도 지수 개발에 기초자료 활용할 수 있을 것이다.

• Asian Pacific Journal of Cancer Prevention
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• 제17권5호
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• pp.2429-2434
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• 2016

Transforming growth factor-B1 ($TGF-{\beta}1$ )and its coreceptor endoglin (ENG) have been shown to contribute to hepatocellular tumor development and malignant progression. Our aim was to evaluate the serum expression levels of $ENG/TGF-{\beta}1$ mRNAs and risk of hepatocellular carcinoma in cirrhotic Egyptian patients. Our study included 77 subjects. Real time polymerase chain reaction was used to evaluate the expression level of ENG and $TGF-{\beta}1$mRNAs. The relative expression ratio of ENG mRNA was 0.82 (0.1 -3.2), 0.66 (0.15-5.3), 0.38(0.007-2.8) and 0.12 (0.00-0.22) and the relative expression ratio of $TGF-{\beta}1$mRNA was 1.4 (0.19 -6.2), 1.2 (0.22-4.3), 1.0 (0.15-4.4) and 0.6 (0.00-2.2) for cirrhotic HCC cirrhotic, HCC only and healthy control groups respectively. Increased ENG and $TGF-{\beta}1$ mRNA gene expression was correlated with TNM clinical stage. The expression ratio in TNM stage III-IV 1.1 (0.07-3.2), 1.55 (0.15-6.2) was statistically significantly higher than that in stage I-II 0.47 (0.007-2.8), 1.0 (0.31-4.4) (P<0.05). Our data suggested that increased ENG and $TGF-{\beta}1$ gene expression may participate in hepatocarcinogenesis and increased risk of HCC in individuals with cirrhosis. Early screening for evidence of cirrhosis and consideration of ENG and $TGF-{\beta}1$ as targets for therapy and treatment strategies are warranted.

• 응용통계연구
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• 제18권1호
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• pp.27-41
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• 2005

『전국 장내 기생충 감염실태조사』를 위해 새로운 표본설계를 하였다. 2000년 인구 주택총조사의 10% 표본조사자료를 조사모집단으로 사용하였고, 조사의 특성상 각종 기생충의 감염율이 아주 낮은 관계로 통상적인 분석방법 대신에 상대위험도과 오즈비를 사용하였다. 표본배정은 네이만 배정의 절충형을 사용하였다. 또한 전국 단위와 특성별 추정이 가능하도록 하였고 추정의 정확성을 측정하기 위해 추정량의 분산식을 유도하였다.

• International Journal of Reliability and Applications
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• 제16권2호
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• pp.55-79
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• 2015

It is well known that using any additional information in the estimation of unknown parameters with new sample of observations diminishes the sampling units needed and minimizes the risk of new estimators. There are many rational reasons to assure that the existence of additional information in practice and there exists many practical cases in which additional information is available in the form of target value (initial value) about the unknown parameters. This article is described the problem of how the prior initial value about the unknown parameters can be utilized and combined with classical Bayes estimator to get a new combination of Bayes estimator and prior value to improve the properties of the new combination. In this article, two classes of Bayes-shrinkage and preliminary test Bayes-shrinkage estimators are proposed for the scale parameter of exponential distribution. The bias, risk and risk ratio expressions are derived and studied. The performance of the proposed classes of estimators is studied for different choices of constants engaged in the estimators. The comparisons, conclusions and recommendations are demonstrated.