• The Korean Journal of Applied Statistics
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• v.19 no.1
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• pp.69-80
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• 2006

In this study, we make an effort to find a method to acquire sensitive information when sensitive populations are consisted of several clusters that vary in size. We suggest and systemize the theoretical validity for applying RRT(Randomized Response Technique) to PPS(Probability Proportional to Size) sampling method and derive the estimate and it's variance of the proportion of sensitive characteristic of population by using the suggested method. We compare the efficiency of the suggested technique by two-stage equal probability sampling. We examine practical aspects of the suggested method of RRT by PPS sampling through field survey.

• The Korean Journal of Applied Statistics
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• v.14 no.1
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• pp.1-11
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• 2001

In PPS sampling, measure of size(MOS) is used to determine the probability of selection of sampling unit. However, some large scale surveys conducted in NSO(National Statistical Office) showed that the sampling units have the similar MOS. In such case, simple cluster sampling method instead of PPS sampling is recommended to give the interviewers a similar work load. In this paper, MSE and CV of the above two sampling methods applied to the 1997 Economically Active Population Survey sample design are compared.

• Survey Research
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• v.11 no.1
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• pp.123-144
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• 2010

In new sample design for Korea Housing Survey to research about housing policy, total strata are forty five because individual results of sixteen regions are estimated. The sample size is determined by sample errors of several variables which are the living area, family income, householder income, and living expenses. The sample size of each region is determined by relative standard error of existing result, and the strata sample size is to use the square root proportion allocation. Enumeration districts are sampled by the probability proportion to size systematic sampling in proportion to the enumeration district size, and the systemic sampling to use assortment characteristics. We considered a new apartment complex because of variation reflections which are rebuilder and redevelopment of houses. To get estimators of mean and variance, we used the design weighting, non-response adjusting, and post-stratification. In order to consider estimation efficiency, we calculate the design effect using estimators of variance.

• Communications for Statistical Applications and Methods
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• v.19 no.1
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• pp.23-32
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• 2012

This paper deals with the bias and variance of regression coefficient estimators in a finite population. We derive approximate formulas for the bias, variance and mean square error of two estimators when we select a fixed-size inclusion probability proportional to the size sample and then estimate regression coefficients by the ordinary least square estimator as well as the weighted least square estimator based on the selected sample data. Necessary and sufficient conditions for the comparison of the two estimators in terms of variance and mean square error are suggested. In addition, a simple example is introduced to numerically compare the variance and mean square error of the two estimators.

• Journal of the Korean Data and Information Science Society
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• v.21 no.4
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• pp.669-679
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• 2010

A sample survey design is suggested for the service satisfaction evaluation of regional education offices based on the sample size of 2009 Gyeongnam regional education offices's customer satisfaction survey. The sample design is developed to fit the goal of evaluation of individual regional offices and allocate at least the minimum sample size to each city or county in Gyeongnam to achieve the goal of the survey. The population is stratified according to the regions and the types of schools, and the sample of schools is selected with proportional to the size of classes within each stratum. Finally, each sample student is selected according to two-stage cluster sampling within each sample school. Weighting averages, weighting totals and so on can be evaluated for analysis purposes. Their variance estimates can be evaluated using re-sampling methods like BBR, Jackknife, linearization-substitution methods, which are generally used for the data from a complex sample.

• Communications for Statistical Applications and Methods
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• v.15 no.6
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• pp.883-897
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• 2008

This paper provides correct informations inflecting the present situation using the sample design in population that the National Statistical Office puts in operation of the mining and manufacturing industry statistical survey in 2006. This paper proposes new sampling design which is able to grasp business fluctuations and provide basic data for the rearing policy and management of the material industry and components industry. These sample design are the modified cut-off method and multivariate Neyman allocation using principal components and sampling method is the probability proportional systematic sampling.

• Journal of the Korean Data Analysis Society
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• v.20 no.6
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• pp.2883-2893
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• 2018

We suggest a stratified conditional unrelated question randomized response model to more efficiently estimate a sensitive character A when the population is composed of several strata. In that model, only the respondents who answered "yes" through randomization device which was consisted of a less sensitive character B and a question forcing to answer "yes" respond to our suggested model and we deal with two allocation problems of proportional allocation and optimal one. We expand the suggested model into two sample stratified conditional unrelated question model to cover the case of unknowing unrelated character and deduce minimal variance through optimal sample size of stratum h. Finally, we show that the suggested model is more efficiency than stratified unrelated models and the stratified Carr et al.'s model (1982) under some given conditions, and show numerically that the smaller the values ${\pi}_{h2}$ and ${\pi}_{hy}$, the more efficiency the fit of the model.

• 한국노년학
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• v.38 no.3
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• pp.593-605
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• 2018

This study examines factors that influence older drivers to consider stopping driving in advance and whose advice plays an important role in the driving cessation decision. Data came from a nationally representative cross-sectional survey of community-dwelling older adults (N=2,076). About two thirds reported that they have considered stopping driving (62.8%) and they preferred to decide by themselves (66.0%). Logistic regression results showed that women and residents in urban areas were twice as likely to consider voluntary driving cessation compared to their counterparts. Each one year increase in age contributed to the probability that respondents would consider driving cessation by five percent. Those with greater difficulties in ADLs due to chronic illnesses were also more likely to consider driving cessation. No sociodemographic and health factors were related to whether older drivers preferred to decide by themselves or listen to others. These results imply that policies to promote self-motivation to stop driving among older drivers would be effective. Furthermore, they suggest it could be important to help older drivers plan their driving cessation in advance while still at a young-old age, and that more attention needs to be paid to men and those living in rural areas among older drivers.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.9
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• pp.161-169
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• 2020

This study investigated the effects and relationships of various stress, school life adjustment and happiness factors among middle school and high school adolescents. The structural model group effects between boy and girl groups were also investigated. Data was employed from the 'Korean Children and Youth Well-Being Index Survey, 2018' while subjects of the analysis included 5,144 students. Based on the education statistics data, the sample was collected by probability proportional to size. Results utilizing structural equation modeling and multigroup analysis showed that first, school stress, friend stress, and look stress had significant effects on adolescent happiness. School life adjustment had positive significant effects on adolescents' happiness. Parent stress, money stress and school stress had significant effects on school life adjustment. Second, the mediating effect of school life adjustment between stress and happiness was significant with parent, school stress, and financial stress. Third, results of the multi-group analysis by level and gender showed that the structure was similar between boys and girls, with the only differences among mediating effects. Boys had significant mediating effects by school stress, and financial stress, while girls had significant mediating effects by school stress, financial stress, and parent stress. Finally, based on the results of the study, practice and policy implications were suggested to support the promotion of adolescents' happiness.