• Asian Pacific Journal of Cancer Prevention
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• v.13 no.7
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• pp.3229-3232
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• 2012

In this study, cancer incidence data were assessed to provide various rates of five year age groups for a given year, lying between two census years. The individual exponential growth rate method is most useful in both population-based and non-population cased cancer registries in India to estimate the population by five yearly age groups and also find the rates of crude rates, age standard rates and cumulative rates. This method has been shown to endure from bias and often results sacrificing the overall growth rate and correction factor must be needful in five year age group population to maintain it. A second method, the difference distribution method is also able to maintain the overall growth rate and overcome the bias in estimation of five yearly age group populations. From this point of view these methods serving a new technique for population estimation by five yearly age groups for inter census years.

• Journal of the Korean Geographical Society
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• v.45 no.6
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• pp.806-819
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• 2010

Population data has been essential and fundamental in spatial analysis and commonly aggregated into political boundaries. A conventional method for population distribution estimation was a regression model with land use data, but the estimation process has limitation because of spatial autocorrelation of the population data. This study aimed to improve the accuracy of population distribution estimation by adopting a Regression-Kriging method, namely RK Model, which combines a regression model with Kriging for the residuals. RK Model was applied to a part of Seoul metropolitan area to estimate population distribution based on the residential zones. Comparative results of regression model and RK model using RMSE, MAE, and G statistics revealed that RK model could substantially improve the accuracy of population distribution. It is expected that RK model could be adopted actively for further population distribution estimation.

• Journal of the Korean Association of Geographic Information Studies
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• v.19 no.3
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• pp.127-143
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• 2016

This study explored the variability in the accuracy of dasymetric population estimation with different grid cell sizes. Dasymetric population maps for Fulton County, Georgia in the US were generated from 30m to 420m at intervals of 30m using an automated intelligent dasymetric mapping technique, population data, and original and simulated land use and cover data. The accuracies of dasymetric population maps were evaluated using RMSE and adjusted RMSE statistics. Lumped fractal dimension values were calculated for the dasymetric population maps generated from resolutions of 30m to 420m using the triangular prism surface area (TPSA) method. The results show that a grid cell size of 210m or smaller is required to estimate population more accurately in terms of thematic accuracy, but a grid cell size of 30m is required to meet an acceptable spatial accuracy of dasymetric population estimation in the study area. The fractal analysis also indicates that a grid cell size of 120m is the optimal resolution for dasymetric population estimation in the study area.

• Journal of Environmental Impact Assessment
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• v.22 no.5
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• pp.525-528
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• 2013

River otter(Lutra lutra) are listed as endangered species and Natural monument in Korea, and this study examined the possibility of extinct of river otter in Hongchon river using with the application of Population Viability Analysis (PVA) technique. In Hongchon river areas population was estimated 9 individuals for the last 1999-2005 years and PVA analysis was done for the next 10 years using the average population of 9. Using the initial population the river otter was estimated 30% of extinct for the next 10 years. This estimation was quite low considering water pollution and construction of highways. Also PVA only used population size lacking in other life history information. Nonetheless river otter population can be in risk of extinction if the current construction of crossovers, cement bank are maintained. Long term information regarding life history needs essential.

• Journal of Environmental Impact Assessment
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• v.18 no.5
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• pp.293-299
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• 2009

Wintering migratory species of white-fronted geese (Anser albifrons) are common visitor in South Korea, and this study examined the survivorship of white-fronted geese in the Junam Reservoir with the application of Population Viability Analysis (PVA) technique. In Junam PVA analysis was done for the next 50 years using factors of breeding population, sex ratios, survivorship in the VORTEX program. As a result white-fronted geese will reach to carrying capacity within 40 years, and population will reach to carrying capacity later when it becomes smaller. Also with a large initial population white-fronted geese will reach to carrying capacity earlier. In conclusion, for the next 50 years the white-fronted geese are expected to a long-term survival with stable condition with survivorship (0.03) and extinction rate (0.0).

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.33 no.3
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• pp.145-153
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• 2015

This study aims to accurately estimate population distribution more specifically than administrative unites using a RK (Regression-Kriging) model. The RK model is the areal interpolation technique that involves linear regression and the Kriging model. In order to estimate a population’s distribution using a sample region, four different models were used, namely; a regression model, RK model, OK (Ordinary Kriging) model and CK (Co-Kriging) model. The results were then compared with each other. Evaluation of the accuracy and validity of evaluation analysis results were the basis RMSE (Root Mean Square Error), MAE (Mean Absolute Error), G statistic and correlation coefficient (ρ). In the sample regions, every statistic value of the RK model showed better results than other models. The results of this comparative study will be useful to estimate a population distribution of the metropolitan areas with high population density

• The Korean Journal of Applied Statistics
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• v.31 no.5
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• pp.621-636
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• 2018

Research on the application of informative sampling technique has been conducted in order to reduce the influence of non-response. Chung and Shin (Korean Journal of Applied Statistics, 30, 993-1004, 2017) showed that the estimation accuracy improved when using exponential response rate information for the parameter estimation if the distribution of errors included in the super population model follows normal distribution. However this method divides the stratum into equally spaced substrata to obtain the sample weight of the informative sampling technique and shows that the accuracy of the estimation improves as the number of substrata increases. In this study, with the given number of total sample size, the optimal substratum boundary points are calculated using equal space, quantile, and LH algorithm; consequently, the results using those methods are compared through simulation. We also studied the criteria to determine the number of substrata and substratum boundaries that can be used in practice with various types of auxiliary variable distributions.

• Journal of Preventive Medicine and Public Health
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• v.42 no.2
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• pp.130-134
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• 2009

Objectives : A method of estimation using 8 populationbased cancer registries databases in Korea(KRCR DB) has been introduced as another strategy for validly estimating the national cancer incidence(NCI) in Korea. The purpose of this study was to evaluate the validity of this method with using the 7 KRCR DBs, excluding Seoul covering 21% of the total population of Korea. Methods : We designed the study method(NCSE_7) as same as the estimating method with using 8 KRCR DBs (NCSE_8) in order to ensure maximal comparability. We defined the expected number of cancer cases in each registry as the number of observed cases and then we added the weighted observed cases according to gender, age and the proportion of the population covered by each registry for the population of the seven regions and the population of all areas, with excluding these seven regions. From the expected number of total cancer incidents, the estimated NCI was calculated by dividing the expected number of cancer cases by the number of the total population. The standard error(SE) of the estimated incidence was also taken from the expected number of total cancer incidents. Results : Compared with the results of the NCSE_8, the overall age-standardized rates(ASR) in men and women became over-estimated and under-estimated, respectively. Primary sites that showed statistically significant differences were the colo-rectum, prostate, breast and thyroid. The index of death certificate only(DCO)and microscopically verified(MV)% indicating levels of data quality were decreased, especially for the brain in DCO% and kidney in the MV%. Conclusions : The database of Seoul regional cancer registry has a key role for the method to estimate the valid nationwide cancer statistics in Korea with using the population-based cancer registries databases.

• The Korean Journal of Applied Statistics
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• v.16 no.2
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• pp.239-246
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• 2003

In small area estimation, Best Linear Unbaised Predictor(BLUP) can be directly implicated ,specially, in use of the time series estimation. If there are correlations between observations and error terms over the time, Kalman Filter method can be used. Therefore, using kalman Filtering technique small area estimation of total of unemployments are estimated by BLUP. And for the example of this study, Economic Active Population Survey data were used.

• Journal of Preventive Medicine and Public Health
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• v.41 no.6
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• pp.380-386
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• 2008

Objectives: Valid data on the national cancer incidence (NCI) is the data should be needed to plan, monitor and evaluate the national cancer control programs. The purpose of this study was to estimate the NCI for 2000-2002 from 8 population-based cancer registries database in Korea (KRCR DB). Methods: We defined the expected number of cancer cases in each registry as the number of observed cases and then adding to the weighted observed cases, according to sex, age groups, and the proportion of the population covered by each registry for the population of the eight regions and the population of all areas with excluding the 8 regions. From the expected number of total cancer incidents, he estimated NCI was calculated by dividing the expected number of cancer cases by he umber of the total population. The standard error (SE) of the estimated incidence was also taken from the expected number of total cancer incidents. Results: The overall estimated crude rates in 2000-2002 ere 267.1 and 219.0 per 100,000 for men and women, respectively. The overall age-standardized rates (ASR) were 290.1 and 180.7 per 100,000, respectively. Compared with the ASRs obtained from Korea National Cancer Incidence database (KNCI DB), the estimated ASRs from the KRCR DB did not show statistically significant differences except for some cancers in women. For the aspect of the SE, index of DCO(death certificate only) and of MV(microscopically verified), the estimated ASRs from the KRCR DB are more accurate and they have higher quality rather than the calculated ASRs from the KNCI DB. Conclusions: We found that this developed method using the KRCR DB is valid and it could be another strategy for estimating the NCI in Korea.