• Journal of applied mathematics & informatics
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• v.8 no.3
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• pp.975-987
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• 2001

We treat the problem of variance estimation for the estimator of population total, which is derived from the calibration estimation procedure corresponding to the levels of auxiliary information under nonresponse situation. We develop the calibrated variance estimation procedure using the fact that the population total and variance as well as the sample total and variance of the auxiliary variable are known. We show that the proposed variance estimation procedure improves the $Lundst\ddot{o}rm$ and $S\ddot{a}rndal's$ (1999) procedure with respect to the variance and nonresponse bias reduction through the simulation study.

• Journal of Internet Computing and Services
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• v.22 no.1
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• pp.1-11
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• 2021

Estimation of distribution algorithm (EDA) is a popular stochastic metaheuristic algorithm. EDA has been widely utilized in various optimization problems. However, it has been shown that the diversity of the population gradually decreases during the iterations, which makes EDA easily lead to premature convergence. This article introduces a hybrid estimation of distribution algorithm (EDA) with differential evolution (DE) based on self-adaptive strategy, namely HEDADE-SA. Firstly, an alternative probability model is used in sampling to improve population diversity. Secondly, the proposed algorithm is combined with DE, and a self-adaptive strategy is adopted to improve the convergence speed of the algorithm. Finally, twenty-five benchmark problems are conducted to verify the performance of HEDADE-SA. Experimental results indicate that HEDADE-SA is a feasible and effective algorithm.

• Korea journal of population studies
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• v.29 no.1
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• pp.269-292
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• 2006

The current environmental problem is global, and threatens the very existence of human beings. Many factors have been argued as the causes of environmental problem. The examples include anthroponcentric human perspective on nature, increase in the knowledge on nature, development of technology, economic growth and unequal distribution, and population increase, etc. The scholars who argues population increase have focused on over-population. However, the estimation of optimum population size has not been attempted in terms of environmental carrying capacity. In such a context, this paper aims at estimating optimum population size in South Korea in terms of environmental carrying capacity. The estimation was done from two approaches. One was based on the state of environment, the other was based on 'the desirable state of environment' Koreans expect. The former is termed an objective approach, while the latter is termed an approach based on social consensus. About 47.5 millions were estimated from the former approach, and 48.5 millions from the latter approach. However, optimum population size increase by 50.5 millions if government increase environmental budget to 2.00% among total budget. As such, different optimum population size is estimated according to the values of variables. The most significant variable determining optimum population size is environmental budget, and followed by supply of clean energy. The estimated optimum population size was based on the time-series data from 1993 to 2002. Therefore, time-series data collected from other years will result in different estimation model, and then different optimum population size will be estimated.

• Journal of Korean Society for Quality Management
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• v.15 no.2
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• pp.61-68
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• 1987

This paper considers the estimation of the parameters of a normal population from which a sample which has been censored at a known point is obtained. Simple estimators are presented which are given in closed forms. It is shown that maximum likelihood estimators are obtained by using the estimation procedure iteratively. Some computer simulation results are given.

• Journal of Oral Medicine and Pain
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• v.39 no.2
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• pp.69-77
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• 2014

Purpose: It aims to verify the applicability of existing age estimation methods derived from data of foreign population groups to Korean population groups. Moreover it is to suggest a new way applicable to practical age estimation on the basis of newly calculated regression formulae from data of Korean population groups and develop a subsidiarily applicable method to the existing method. Methods: Ratio of pulp cavity to dental crown was calculated by measuring the height and width of dental crowns and pulp cavities at the cervical line from 4,034 first and second upper molars, first and second upper premolars, first and second lower molars and first and second lower premolars on both left and right sides of 400 patients who had been treated in Dental Hospital of Yonsei University College of Dentistry, and regression equations were derived from the values of the ratio. Results: The equation with correlation coefficients the highest among females was as follows: age=$107.96-75.684{\times}{\sharp}17$ TCHI-$53.741{\times}{\sharp}26$ TCVI-$40.664{\times}{\sharp}45$ TCVI-$56.307{\times}{\sharp}46$ TCVI. Randomized anohter Korean female subjects (n=20) are applicated to the new equation. Mean of error of estimate is 10.322 years, standard deviation is 12.852 years. Minimum of error of estimate is 1.018 years, maximum is 21.365 years Conclusions: The error range of age estimation was found to be slightly wider when the existing regression formulae of Drusini were applied to Korean population groups. Also age estimation in females using the ratio of pulp cavity to dental crown measured with the length and width of dental crowns and pulp cavities from maxillomandibular molars was observed to have the highest reliability in the research. However, we consider that advanced equations of regression are needed to apply to both molars and premolars of males and females in the future.

• Journal of Korean Society of Rural Planning
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• v.12 no.3 s.32
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• pp.39-42
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• 2006

The purpose of this study is to develop rural population model adapting cohort survival method with sift-share effects. Administrative district in this study is below Myun: about 2,000 population. Population data of rural area in 1990, 1995, and 2000 by age cohort were selected for applying developed model. Damping coefficient from population data was calculated as 7% and results applying this coefficient in rural population data below the error from 12% to 1.06%. In detail, most of cohorts fitted with developed model except from 15 to 29 age groups. Application result of small population area; DaesulMyun revealed that main factor of population change is not natural change but migration.

• 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 Korea Technology Innovation Society
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• v.15 no.2
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• pp.323-344
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• 2012

We investigate and analyze the effect of population density on digital divide in Africa by applying the panel data analysis therein. From the estimation results based on the panel data analysis, it has been found that population density as well as both levels of income and education has a significant effect on the digital divide in African region. In particular, the fact that the variable of population density makes a significantly influential role implies that the construction cost of information infrastructure in Africa behaves such a considerable obstacle to Africa wishing to enter into information society. In conclusion, throughout the integration of the estimation results in the paper, the following implications for economic cooperation with Africa can be drawn. The estimation results mentioned above strongly imply that the variable referred to as population density should be considered in selecting which countries to assist for construction of information infrastructure.

• Animal Bioscience
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• v.37 no.5
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• pp.795-806
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• 2024

Objective: Karan Fries (KF), a high-producing composite cattle was developed through crossing indicine Tharparkar cows with taurine bulls (Holstein Friesian, Brown Swiss, and Jersey), to increase the milk yield across India. This composite cattle population must maintain sufficient genetic diversity for long-term development and breed improvement in the coming years. The level of linkage disequilibrium (LD) measures the influence of population genetic forces on the genomic structure and provides insights into the evolutionary history of populations, while the decay of LD is important in understanding the limits of genome-wide association studies for a population. Effective population size (N_e) which is genomically based on LD accumulated over the course of previous generations, is a valuable tool for e valuation of the genetic diversity and level of inbreeding. The present study was undertaken to understand KF population dynamics through the estimation of N_e and LD for the long-term sustainability of these breeds. Methods: The present study included 96 KF samples genotyped using Illumina HDBovine array to estimate the effective population and examine the LD pattern. The genotype data were also obtained for other crossbreds (Santa Gertrudis, Brangus, and Beefmaster) and Holstein Friesian cattle for comparison purposes. Results: The average LD between single nucleotide polymorphisms (SNPs) was r² = 0.13 in the present study. LD decay (r² = 0.2) was observed at 40 kb inter-marker distance, indicating a panel with 62,765 SNPs was sufficient for genomic breeding value estimation in KF cattle. The pedigree-based N_e of KF was determined to be 78, while the N_e estimates obtained using LD-based methods were 52 (SNeP) and 219 (genetic optimization for N_e estimation), respectively. Conclusion: KF cattle have an N_e exceeding the FAO's minimum recommended level of 50, which was desirable. The study also revealed significant population dynamics of KF cattle and increased our understanding of devising suitable breeding strategies for long-term sustainable development.

• Communications for Statistical Applications and Methods
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• v.20 no.4
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• pp.247-257
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• 2013

A variety of practical problems can be addressed in the framework of rotation (successive) sampling. The present work presents a sample rotation pattern where sampling units are drawn on two successive occasions. The problem of estimation of population variance on current (second) occasion in two - occasion successive (rotation) sampling has been considered. A class of estimators has been proposed for population variance that includes many estimators as a particular case. Asymptotic properties of the proposed class of estimators are discussed. The proposed class of estimators is compared with the sample variance estimator when there is no matching from the previous occasion. Optimum replacement policy is discussed. Results are supported with the empirical means of comparison.