• 응용통계연구
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• 제34권6호
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• pp.923-936
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• 2021

표본조사에서는 다수의 무응답이 발생하며 이를 적절히 처리하는 다양한 방법이 개발되었다. 특히 무응답이 관심변수에 영향을 받고 이로 인해 발생한 편향은 추정의 정확성을 크게 떨어뜨리며 무응답 처리를 어렵게 한다. 최근 Chung과 Shin (2017, 2020)은 알려진 모수적 초모집단 모형과 응답률 모형을 이용하여 추정의 정확성을 향상한 추정량을 제안하였다. 본 연구에서는 초모집단 모형의 형태를 일반화하여 비모수적 함수 형태를 설정한 후 이를 기반으로 얻어진 편향을 적절히 처리한 편향 보정 평균추정량을 제안하였다. 모의실험을 통해 본 연구에서 제안한 방법의 우수성을 확인하였다.

• Journal of the Korean Statistical Society
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• 제29권4호
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• pp.455-471
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• 2000

A new method is developed for estimating the mean of a population which has a linear trend. The proposed estimator is based on the balanced systematic sampling method and the concept of interpolation. The efficiency of the proposed method is compared with that of existing methods.

• 수산경영론집
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• 제36권1호
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• pp.155-166
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• 2005

Since 1980's, fishery household population have been continuously in a down slope with a 5$\%$ annual decreasing rate in Korea. With a particular situation that the scale of over 60s population has been soaring compared with that of under 16 aged population plunging, some difficulties have been raised with the respect of labor supply into fishery communities. This study is aimed at analyzing the tendency of fisheries population with the change of economic development rates and prospect a future fisheries population with the consideration of present decreasing rate. Model results indicate that the tendency of future fishery household population would be decreased by 4.96$\%$ annually through a decade from 2000. Interestingly, it is predicted that the decreasing rate of male fishery household population would be faster than that of female. Consequently, women would hold a greater part in Fishery household population in 2010. In addition, the fishery household population of 40s and 50s would increase from 36$\%$ to 49$\%$, that of over 60s from 21$\%$ to 37$\%$. In conclusion, as a population over 40's encompass almost 90$\%$ in the total population, the fishing communities have a difficulty in shortage of the young workforce.

• 한국소음진동공학회논문집
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• 제24권4호
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• pp.348-356
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• 2014

To understand the relationship between road-traffic noise and urban components such as population, building, road-traffic and land-use, the city of Cheongju that already has road-traffic noise maps of daytime and nighttime was selected for this study. The whole area of the city is divided into square cells of a uniform size and for each cell, the urban components are estimated. A spatial representative noise level for each cell is determined by averaging out population-weighted facade noise levels for noise exposure population within the cell during nighttime. The relationship between the representative noise level and the urban components is statistically modeled at the cell level. Specially, we introduce a spatial auto regressive model and a spatial error model that turns out to explain above 85 % of the noise level. These findings and modeling methods can be used as a preliminary tool for environmental planning and urban design in modern cities in consideration of noise exposure.

• Asian-Australasian Journal of Animal Sciences
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• 제15권6호
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• pp.767-771
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• 2002

Breeding efficiencies were compared among three population schemes: a single population, a population with two subpopulations and a population with three sub-populations. A simulation experiment of selection was carried out for 10 generations with 20 replications each by comparing average breeding values and inbreeding coefficients among the three population schemes. Phenotypes of three traits were generated with a model comprising 36 loci, each with additive genetic effects and residuals distributed normally. Among the three population schemes, the single population scheme was definitely superior to the other two with regards to selection response and inbreeding. The multiple sub-population scheme was, however, considered to be an alternative population scheme when the difference in economic weights of the traits was small among the sub-populations, assuming moderate inbreeding depression for traits and crossbreeding. The scheme with two sub-populations had a higher genetic value than that with three subpopulations; however, the genetic values of the schemes were comparable when maternal heterosis was taken into account. The choice of population schemes may depend on the cost-sharing policy between the breeding population and the commercial population rather than just the breeding efficiency.

• 약학회지
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• 제46권1호
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• pp.63-68
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• 2002

The purpose of this study was to estimate the population pharmacokinetics of clarithromycin in healthy adult Korean and to investigate the factors influencing the pharmacokinetics of clarithromycin. The population pharmacokinetic parameters of clarithromycin were calculated with the data from healthy adult Koreans. A total of 798 plasma concentrations obtained from 78 subjects after administration of a single oral dose of 250 mg or 500 mg were used for the modeling. The concentration-time data were fitted to a one-compartment open model assuming a first-order absorption and elimination with no lag time. The correlations between various factors [such as sex, age, height, weight, sect creatinine (Scr) and dose and pharmacokinetic parameters were estimated with stepwise linear recession analyses. The selected covariates were incorporated in the population model of NONMEM, and the importance of each covariate was investigated by means of backwards elimination. The apparent clearance (CL/F) was significantly correlated to Scr and sex, and the apparent volume of distribution (Vd/F) was significantly correlated to Scr and height in a nonlinear relationship. The population values of Ka was 1.8 h $r_{-1}$, CL/F was 37.71 L/hr, Vd/F was 200 L and t/ sub 1/2 / was 3.68 hrs for a male Korean with 170 m height and 1.0 mg/dL Scr.

• 농촌계획
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• 제30권2호
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• pp.79-96
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• 2024

The purpose of this study is to analyze the factors affecting residential mobility between urban and rural. After classifying urban and rural region based on discriminatory attributes of the regions, we applied a multinomial logistic model, using the sample data of 2020 Korea Population and Housing Census. The major findings are as follows. The young highly educated in cities avoided rural. The young less educated in rural engaged in 2, 3th industries as well as agricultural industry, but remained in low-paying and unstable jobs. In addition, various classes moved to rural and rising house prices in cities pushed people to rural. Therefore, it is necessary to develop diversified regional industry models and provide opportunities for high quality and stable jobs in rural by linking industrial demand, education and jobs. Also, preserving the rural environment, settlement conditions and residential environment are needed for satisfying various needs of urban residents who migrate to rural areas. While regional policies so far have focused on maintaining the population size and promoting a population influx, rural development and population policies should be established in a way that responds to diverse population classes in an era of population decline.

• Journal of applied mathematics & informatics
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• 제9권2호
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• pp.807-815
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• 2002

We consider a more general linear regression super-population model than the one of Chaudhuri and Stronger(1992) . We can find the same type of the best linear unbiased(BLU) predictor as that of Chaudhuri and Stenger and see that the optimal design is again a purposive one which prescribes choosing one of the samples of size n which has $\chi$ closest to $\bar{X}$.

• Journal of applied mathematics & informatics
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• 제30권1_2호
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• pp.183-200
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• 2012

A two-strain epidemic model with an age structure mutation and varying population is studied. By means of the spectrum theory of bounded linear operator in functional analysis, the reproductive numbers according to the strains, which associates with the growth rate ${\lambda}^*$ of total population size are obtained. The asymptotic stability of the steady states are obtained under some sufficient conditions.

• Journal of applied mathematics & informatics
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• 제7권3호
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• pp.925-940
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• 2000

The spatial spread of a disease in an SIRS epidemic model with immunity imparted by subclinical infection on a population has been considered. The incidence rate of infection and the rate of immunization are both of nonlinear type. The dynamics of the infectious disease and its endemicity in local and global sense have been investigated.