• Asian-Australasian Journal of Animal Sciences
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• v.32 no.2
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• pp.159-169
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• 2019

Objective: Models for genomic selection assume that the reference population is an unselected population. However, in practice, genotyped individuals, such as progeny-tested bulls, are highly selected, and the reference population is created after preselection. In dairy cattle, the intensity of selection is higher in males than in females, suggesting that cows can be added to the reference population with less bias and loss of accuracy. The objective is to develop formulas applied to any genomic prediction studies or practice with preselected animals as reference population. Methods: We developed formulas for calculating the reliability and bias of genomically enhanced breeding values (GEBV) in the reference population where individuals are preselected on estimated breeding values. Based on the formulas presented, deterministic simulation was conducted by varying heritability, preselection percentage, and the reference population size. Results: The number of bulls equal to a cow regarding the reliability of GEBV was expressed through a simple formula for the reference population consisting of preselected animals. The bull population was vastly superior to the cow population regarding the reliability of GEBV for low-heritability traits. However, the superiority of reliability from the bull reference population over the cow population decreased as heritability increased. Bias was greater for bulls than cows. Bias and reduction in reliability of GEBV due to preselection was alleviated by expanding reference population. Conclusion: Cows are easier in expanding reference population size compared with bulls and alleviate bias and reduction in reliability of GEBV of bulls which are highly preselected than cows by expanding the cow reference population.

• Korean Journal of Remote Sensing
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• v.36 no.1
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• pp.83-92
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• 2020

The purpose of this work was to apply geographical information system (GIS) for geostatistical analyzing by selecting a semi-variogram model to quantify the spatial correlation of the population distribution with residential neighborhoods in the both sides of Mosul city. Two hundred and sixty-eight sample sites in 240 ㎢ are adopted. After determining the population distribution with respect to neighborhoods, data were inserted to ArcGIS10.3 software. Afterward, the datasets was subjected to the semi-variogram model using ordinary kriging interpolation. The results obtained from interpolation method showed that among the various models, Spherical model gives best fit of the data by cross-validation. The kriging prediction map obtained by this study, shows a particular spatial dependence of the population distribution with the neighborhoods. The results obtained from interpolation method also indicates an unbalanced population distribution, as there is no balance between the size of the population neighborhoods and their share of the size of the population, where the results showed that the right side is more densely populated because of the small area of residential homes which occupied by more than one family, as well as the right side is concentrated in economic and social activities.

• Journal of Korean Society of Rural Planning
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• v.29 no.4
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• pp.183-189
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• 2023

As South Korea faces a general decline in population, similar to other regions, its rural areas are also experiencing a downward trend. This study examines how the scale and shifts in population within rural towns(eup·myeon) are affecting the number of essential services such as hospitals, laundry shops, and beauty salons. Our analysis encompassed the populations of 1,403 towns, excluding nine areas due to lack of data as of 2020. Since the availability of basic services can vary with population size, we normalized the figures to reflect the number of services per 10,000 people, allowing for a comparative analysis across different population sizes. Generally, areas with more people showed an increase in the number of services per capita. Our review of changes from 2000 to 2020 revealed patterns in how service numbers adjust with population variations. Future research should delve into more detailed trends of these facilities and forecast the rural population's future to ensure that residents in areas where service sustainability may be challenging will have full access to necessary services.

• The Korean Journal of Ecology
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• v.6 no.4
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• pp.10-20
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• 1983

Morphological and ecological comparions are made between specimens of Cobitis koreensis KIM and the geographically restricted population of the Cobitid fish which is found along the Begchon stream, Puangun, Cholla-bugdo province over a 12-month period of 1982 and 1983. The Begchon population is tentatively identified as Cobitis koreensis, but the color patterns and two morphometric proportions differ widely fromthose reported previously for this species. In addition to these character, it is easily distinguished from C. koreensis by the smaller body size, by having the larger egg size and the less egg number in female during the breeding season. As the differentiation of this population is primarily due to geographically isolation, it is supposed that Begchon cobitid population may be an undescribed distinct subspecies of K. koreensis or above the conventional subspecies level.

• Journal of the Korean Statistical Society
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• v.29 no.2
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• pp.169-185
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• 2000

Given a random sample of size N (unknown) with density f(x│$\theta$), suppose that only n observations which lie outside a region r are recorded. On the basis of n observation, the Bayes estimators of $\theta$ and N are considered and their asymptotic expansions are developed to find the third order asymptotic properties with those of the maximum likelihood estimators and the Bayes modal estimators. The asymptotic m.s.e.'s of these estimators are expressed. An example is given to illustrate the results obtained.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.8
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• pp.1063-1072
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• 2012

Effective population size ($N_e$) is an important measure to understand population structure and genetic variability in animal species. The objective of this study was to estimate $N_e$ in Sapsaree dogs using the information of rate of inbreeding and genomic data that were obtained from pedigree and the Illumina CanineSNP20 (20K) and CanineHD (170K) beadchips, respectively. Three SNP panels, i.e. Sap134 (20K), Sap60 (170K), and Sap183 (the combined panel from the 20K and 170K), were used to genotype 134, 60, and 183 animal samples, respectively. The $N_e$ estimates based on inbreeding rate ranged from 16 to 51 about five to 13 generations ago. With the use of SNP genotypes, two methods were applied for $N_e$ estimation, i.e. pair-wise $r^2$ values using a simple expectation of distance and $r^2$ values under a non-linear regression with respective distances assuming a finite population size. The average pair-wise $N_e$ estimates across generations using the pairs of SNPs that were located within 5 Mb in the Sap134, Sap60, and Sap183 panels, were 1,486, 1,025 and 1,293, respectively. Under the non-linear regression method, the average $N_e$ estimates were 1,601, 528, and 1,129 for the respective panels. Also, the point estimates of past $N_e$ at 5, 20, and 50 generations ago ranged between 64 to 75, 245 to 286, and 573 to 646, respectively, indicating a significant $N_e$ reduction in the last several generations. These results suggest a strong necessity for minimizing inbreeding through the application of genomic selection or other breeding strategies to increase $N_e$, so as to maintain genetic variation and to avoid future bottlenecks in the Sapsaree population.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.12
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• pp.1672-1679
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• 2013

Linkage disequilibrium between markers or genetic variants underlying interesting traits affects many genomic methodologies. In many genomic methodologies, the effective population size ($N_e$) is important to assess the genetic diversity of animal populations. In this study, dairy cattle were genotyped using the Illumina BoviveHD Genotyping BeadChips for over 777,000 SNPs located across all autosomes, mitochondria and sex chromosomes, and 70,000 autosomal SNPs were selected randomly for the final analysis. We characterized more accurate linkage disequilibrium in a sample of 96 dairy cattle producing milk in Korea. Estimated linkage disequilibrium was relatively high between closely linked markers (>0.6 at 10 kb) and decreased with increasing distance. Using formulae that related the expected linkage disequilibrium to $N_e$, and assuming a constant actual population size, $N_e$ was estimated to be approximately 122 in this population. Historical $N_e$, calculated assuming linear population growth, was suggestive of a rapid increase $N_e$ over the past 10 generations, and increased slowly thereafter. Additionally, we corrected the genomic relationship structure per chromosome in calculating $r^2$ and estimated $N_e$. The observed $N_e$ based on $r^2$ corrected by genomics relationship structure can be rationalized using current knowledge of the history of the dairy cattle breeds producing milk in Korea.

• Health Policy and Management
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• v.14 no.2
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• pp.1-16
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• 2004

The study purpose was to find which factors affect selection of hospital network types. This study used the 1998 American Hospital Association Annual Survey Database from Health Forum. Among these U.S. hospitals, the researcher selected hospitals located in Metropolitan Statistical Areas. Therefore the final observation cases for analysis are 1,971 Metropolitan Statistical Area hospitals in the United States. To identify significant variables influencing hospital network types, the study used proportional odds logistics regression model on population size, Health Maintenance Organization penetration rate, and market competition rate of area including a hospital, types of hospital ownership, hospital bed size, proportion of Medicare patients and Medicaid patients in total hospital patients, and occupancy rate. Contrary to conventional wisdom, selection of hospital network types was influenced by population size of area which a hospital located, types of ownership, hospital bed size, and proportion of medicare patients rather than Health Maintenance Organization penetration. Population size 1,000,000-2,499,999 had the highest probability of selecting type IV (clinical-vertical integration) from an independent hospital, and a religious group owned hospitals and for-profit owned hospitals had the highest probability of selecting Type IV (clinical-vertical integration) from an independent hospital. A bed size had positive relation on selecting Type IV (clinical-vertical integration) from an independent hospital. Unlikely general belief that the selecting types of hospital network was determined by the change of health insurance policy such as Health Maintenance Organizations and Preferred Provider Organizations, the types of hospital network were influenced by community characteristics such as population size, and hospital characteristics.

• Journal of the Korea Fashion and Costume Design Association
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• v.25 no.3
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• pp.157-164
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• 2023

The purpose of this study is to compare and analyze bust point information presented in literature and the 8th Korean Anthropometric Survey (Size Korea 2021) as a basis for pattern making for Korean adult women. Therefore, the the bust point position was analyzed through the length from the side neckline to the bust point and the horizontal length from the bust point to the chest. The results are as follows. First, Size Korea's population shows an increase in bust circumference and Side Neck Point to Bust Point with age, with the largest Bust-Point Breadth in the 30s, followed by the 20s, 40s, 60s, and 50s. Second, the Bust-Point Breadth in the female Basic Bodice pattern of Kang Soon-hee, and Oh Sun-hee, which were created from the bust circumference measurements of Size Korea's population, was wider than the measurements, and the difference was verified as a highly significant. Third, in the female Basic Bodice pattern of Kang Soon-hee, and Oh Sun-hee created with the bust circumference dimensions of Size Korea's population, the length of Neck Point to Bust Point was shorter than the measured value, and the difference was highly significant. Fourth, the Bust-Point Breadth and Neck Point to Bust Point in the female Basic Bodice pattern of Kang Soon-hee, and Oh Sun-hee, which were created with the bust circumference of the population of Size Korea by age, were analyzed in different age groups and showed significant differences from the measurements of Size Korea.

• Korea journal of population studies
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• v.11 no.2
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• pp.11-21
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• 1988