• Journal of the Korean Data and Information Science Society
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• v.17 no.4
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• pp.1309-1317
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• 2006

The paper considers some Bayes estimators of the finite population mean with auxiliary information under priors which are scale mixtures of normal, and thus have tail heavier than that of the normal. The proposed estimators are quite robust in general. Numerical methods of finding Bayes estimators under these heavy tailed priors are given, and are illustrated with an actual example.

• Journal of applied mathematics & informatics
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• v.5 no.3
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• pp.785-796
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• 1998

In this paper we propose a model of HIv population through method of phases with non-Markovian evolution of immi-gration. The analysis leads to an explicit differnetial equations for the generating functions of the total population size. The detection process of antibodies (against the antigen of virus) is analysed and an explicit expression for the correlation functions are provided. A measure of bunching is also introduced for some particular choice of parameters.

• Journal of the Korean Data and Information Science Society
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• v.24 no.6
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• pp.1543-1550
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• 2013

In this paper, we study Bayesian estimation for the finite population proportion in binary data under selection bias. We use a Bayesian nonignorable selection model to accommodate the selection mechanism. We compare four possible estimators of the finite population proportions based on data analysis as well as Monte Carlo simulation. It turns out that nonignorable selection model might be useful for weekly biased samples.

• 대한예방의학회:학술대회논문집
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• 2003.04a
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• pp.30-37
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• 2003

o Cohort study became the major approach to study of chronic diseases such as CVD and cancer o Cohort can be population-based or volunteer-based o Types of be population-be categorized by source population and selection mechanism o More and more cohort studies involve biological specimens, such as blood, urine, toenail, cheek cells, etc. o Multi-center and multi-national collaboration is an effective way to increase sample size. o Current statistical method typically use time-to-event analysis by Cox proportional hazard model.

• Journal of the Korean Statistical Society
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• v.27 no.3
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• pp.331-348
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• 1998

In this paper, we have proposed some robust Bayes estimators using ML-II priors as well as certain empirical Bayes estimators in estimating the finite population mean in the presence of auxiliary information. These estimators are compared with the classical ratio estimator and a subjective Bayes estimator utilizing the auxiliary information in terms of "posterior robustness" and "procedure robustness" Also, we have addressed the issue of choice of sampling design from a robust Bayesian viewpoint.

• Nonlinear Functional Analysis and Applications
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• v.26 no.1
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• pp.83-92
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• 2021

This paper studies approximate solutions for a class of nonlinear diffusion population models. Our methods are to use the fundamental solution of heat equations to construct integral forms of the models and the well-known Banach compression map theorem to prove the existence of positive solutions of integral equations. Non-steady-state local approximate solutions for suitable harvest functions are obtained by utilizing the approximation theorem of multivariate continuous functions.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.1
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• pp.111-115
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• 2012

Variants of X-ray repair cross-complementing group 1 (XRCC1) are involved in the development of cancer, but studies investigating the association of XRCC1-77T>C polymorphism with cancer risk have reported conflicting results. To clarify the effect of the XRCC1 -77T>C polymorphism on cancer risk, we performed a meta-analysis by conducting searches of the published literature in PubMed, Embase and CBM databases. Finally, 13 studies were included into our meta-analysis, involving a total of 11, 678 individuals. Subgroup analyses were performed by ethnicity and cancer type. The results of this meta-analysis showed that there was significant association between the C variant of XRCC1-77T>C polymorphism and cancer risk in all four genetic comparison models (ORC vs. T =1.19, 95%CI 1.07-1.31, P = 0.001; OR homozygote model =1.28, 95%CI 1.07-1.52, P = 0.007; OR recessive genetic model =1.22, 95%CI 1.04-1.44, P = 0.015; OR dominant model =1.21, 95% CI 1.07-1.35, P = 0.001). In the subgroup analyses based on ethnicity, the association was still significant in the Asian population (all p values<0.001), but not in the Caucasian population (all p values > 0.05). Thus, the XRCC1 -77T>C polymorphism is associated with cancer risk, and individuals with XRCC1 -77C variant have a significantly higher cancer risk, particularly in the Asian population.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.9
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• pp.4403-4407
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• 2012

Background: Glutathione-S-Transferase T1 (GSTT1) gene has been shown to be involved in the development of esophageal cancer. However, the results have been inconsistent. In this study, the authors performed a meta-analysis to clarify the association between GSTT1 polymorphism and esophageal cancer risk among Chinese Han population. Methods: Published literature from PubMed, the China National Knowledge Infrastructure and Wanfang Data were searched. Pooled odds ratio (OR) and 95% confidence interval (95%CI) was calculated using a fixed- or random-effects model. Results: Eleven studies with a total of 2779 individuals were included in the meta-analysis. The results showed that GSTT1 null genotype was significantly associated with esophageal cancer risk in Chinese (OR = 1.31, 95%CI 1.12 to 1.53, p = 0.001). Further sensitivity analyses confirmed the significant association. The cumulative meta-analysis showed a trend of an obvious association between GSTT1 null genotype and esophageal cancer risk as information accumulated by year. Conclusions: This meta-analysis suggests a significant association of GSTT1 null genotype with esophageal cancer risk in the Chinese Han population.

• International Journal of Highway Engineering
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• v.14 no.4
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• pp.133-140
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• 2012

PURPOSES : Traffic situation of Seoul City is different each administrative district. because each administrative district population, average travel speed, etc are different. thus, regionally differentiated policy is necessary. METHODS : In this study, first, it is to implement the cluster analysis using the traffic factor of twenty-five administrative districts in Seoul, categorize it into the cluster and understand the properties. second, related factors of speed were derived. and method to increase the speed was investigated. we choose the eleven traffic factors such as the number of traffic accident cases, total length, speed, the number of cross section, the number of cross section per km, the rate of roads, registered cars, population attending office and school, population density, area. RESULTS : In the results, first, we could categorize the Seoul-City administrative district into three clusters. in order to find Factors associated with speed a simple regression analysis was performed. and the number of intersections per km is closely related to the speed. CONCLUSIONS : Through this study, transportation policies reflecting local traffic-related characteristics are required.

• Journal of Korean Society of Rural Planning
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• v.19 no.2
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• pp.107-120
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• 2013

A lot of rural development projects have been planned and implemented for revitalizing rural areas in South Korea. However, it is not easy to properly evaluate and quantitatively analyze project outcomes. For this reason only selected regions have been evaluated for rural projects by government agencies. In this study, we analyzed the purpose and the contents of the Rural Village Development Project (RVDP) and Green Tourism Village Project (GTVP) to find indicators for evaluating results of rural projects using logistic regression analysis. Outputs of this study show that RVDPs increase regional population and GTVPs positively affect the sales of agricultural products. We also estimated the spatial distribution of project effects through spatial autocorrelation analysis and local-spatial autocorrelation analysis. Results show that the Moran's I values for the proportion of farmers with avocational jobs, product sales changes, and population growth in Jeol-La province are positive and the biggest one is population growth. Especially, key areas of agricultural product sales are widely distributed.