• Journal of Korean Society of Rural Planning
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• v.13 no.4
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• pp.9-22
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• 2007

With the establishment of municipalities, public interest in small towns in Korea has been on the rise. To initiate an effective study and suggest subsequent policies for small towns, it is necessary to analyze and discuss substantive issues based on specific conditions of these small towns. The primary objective of this paper is to categorize small towns into types and to analyze the peculiarities and differences of their internal factors. The focus of this research is to determine the general characteristics of the classified towns and to suggest specific revitalization and specialized studies about them. In the main analysis of this paper, 39 small towns are divided into sets according to urban rank, conditions of location, and size of the population in the central site. Furthermore, distinctions of the divided towns are analyzed using three constituents for urban organization, including populations, activities, and facilities/land. From the research results, it was determined that there is a difference between small town types, according to population, land cost, and urban activities, based upon the urban rank and size of the population in the central site. Therefore, this paper concludes it is necessary to conduct further studies on time series analysis regarding the peculiarity changes of the types, and to complement the variables for future related studies.

• Korean Journal of Environmental Biology
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• v.21 no.4
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• pp.337-341
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• 2003

Habitat heterogeneity can enhance biological diversity by providing variation in structural diversity. This paper reviewed heterogeneous habitat serves as a population stability and superior demographic performance (e.g., high density, survivorship, reproductive rate) can be observed compared with organisms with inferior demographic performance. The idea of habitat variation has been further developed in modelling. Furthermore the size and configuration (distribution) of a patch (of a particular habitat type) become effective for the stability of population through hiding places and food resources. Species diversity is related to habitat complexity that provides structural diversity to ground -dwelling organisms. Finally coarse woody debris can enhance habitat complexity thus stabilizing population fluctuation and increasing survivorship.

• Communications for Statistical Applications and Methods
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• v.23 no.1
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• pp.47-55
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• 2016

Stratified cluster sampling has been widely used for effective parameter estimations due to reductions in time and cost. The probability proportional to size (PPS) sampling method is used when the number of cluster element are significantly different. However, simple random sampling (SRS) is commonly used for simplicity if the number of cluster elements are almost the same. Also it is known that the ratio estimator produces a good performance when the total number of population elements is known. However, the two stage cluster estimator should be used if the total number of elements in population is neither known nor accurate. In this study we suggest a composite estimator by combining the ratio estimator and the two stage cluster estimator to obtain a better estimate under a certain population circumstance. Simulation studies are conducted to compare the superiority of the suggested estimator with two other estimators.

• Journal of Ecology and Environment
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• v.29 no.5
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• pp.411-414
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• 2006

The mating systems of two groups of natural populations of Gleditsia japonica var. koraiensis in Korea were determined using allozyme analysis. The result suggests that G. japonica var. koraiensis is predominantly outcrossing. The tm values of eight populations in Korea varied from 0.667 (Mdh-1) to 0.938 (ldh-1), giving an average 0.820. Population and individual outcrossing estimates were associated with flowering tree density or degree of spatial isolation. The reason for relatively low outcrossing rates of some populations could be attributed to reduction of effective population sizes of sib for the medicine, small population size, and isolation of flowering mature trees. The heterozygote excesses were observed in some natural populations, whereas other populations exhibited varying degrees of inbreeding and heterozygotes deficit. Thus, selection against homozygotes operated in the progeny populations throughout the life cycle.

• The Transactions of the Korea Information Processing Society
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• v.6 no.10
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• pp.2728-2739
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• 1999

This paper proposes an effective fusion algorithm for retrieval results from heterogeneous information sources in federated digital libraries. The algorithm determines the population of documents retrieved from involved information sources for a given query and evaluates the degree of relevance between the query and the population. The evaluated results are used as relevance distribution information for collection fusion. The main informations used for the fusion are relevance distribution among collections, the population size N, and ranking information of relevant documents in their origin. We also present th performance evaluation of the algorithm by developing the prototype of a meta-searcher.

• Journal of the Korean Regional Science Association
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• v.9 no.1
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• pp.45-63
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• 1993

University enrollment has long been regarded as one of the major factors inducing population concentration in Seoul and the Capital Region of Korea. Consequently, since early 1980's increases in enrollment and new establishments of extention universities beyond the boundary of Seoul, has been promoted, while university enrollment quota in Seoul has been strictly controlled. The degree of actual population dispersal, however, resulting from such a university enrollment policy has not been empirically tested. This paper aims at: First, identifying the trend of population growth and evolution process of the university enrollment policy in the Capital Region; Second, comparing the degree of influence of university enrollment on population concetration factors; Third, measuring actual effect of the enrollment control on population dispersal out of Seoul and the Capital Region. Major findings are as follows: First, only a week correlation between population and university enrollment growth trends was found; Second, the relative degree of influence on population concentration in the Capital Region, were order, in the order of magnitude, the physical amenity factor, the socio-cultural amenity factor, the employment climate factor and the educational factor. Third, and most improtant, based on the comparison of spatial distribution of graduated high schools and current residence of the selected university students, the gap between the two distributions was revealed and the inter-regional student population movement was estimated. The result shows that in Seoul's case about one-half of and in Kyunggi Province's case about one-fifth of university enrollment size, contributes to population concentration into Seoul. Fourth, as to the universities outside of the Capital Region, little effect in the case of universities located within the commuting distance, and a little effect on population dispersal in the case of universities located beyond commuting distance, were found. In sum, it seems clear that university enrollment policy in the Capital Region, especially in Inchon/Kyunggi Province has not been effective on student population dispersal out of Seoul and the Capital Region. Therefore, it is strongly recommended that university enrollment policy be throughly re-examined from its goal to the implementation means.

• Korean Journal of Ecology and Environment
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• v.51 no.2
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• pp.168-173
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• 2018

Mauremys reevesii is a Korean endemic turtle, and designed as an endangered species and national monument in South Korea. Recently, the population of the species has been dramatically declining because of habitat destruction, pollution and illegal capture. Moreover, small population size, difficulty of securing individuals, and lack of research are factors that impede the effective management of the species. In this study, we tested the effect of individual breeding and feeding on the seven juveniles of M. reevesii. Our results showed individual breeding and feeding were guaranteed the effective growth and development. Noticeable growth was confirmed in both body weight and carapace length. Moreover, the size difference among the individuals appeared at the start of this study decreased at the end of this study. Artificial breeding during the wither season was not caused disorders on the growth, behavior and morphology. This individual breeding may lead to effective growth and development, and it will be a way to increase the survival rate when the juveniles released into the wild.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.6
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• pp.772-779
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• 2013

Linkage disequilibrium (LD) plays an important role in genomic selection and mapping quantitative trait loci (QTL). In this study, the pattern of LD and effective population size ($N_e$) were investigated in Chinese beef Simmental cattle. A total of 640 bulls were genotyped with IlluminaBovinSNP50BeadChip and IlluminaBovinHDBeadChip. We estimated LD for each autosomal chromosome at the distance between two random SNPs of <0 to 25 kb, 25 to 50 kb, 50 to 100 kb, 100 to 500 kb, 0.5 to 1 Mb, 1 to 5 Mb and 5 to 10 Mb. The mean values of $r^2$ were 0.30, 0.16 and 0.08, when the separation between SNPs ranged from 0 to 25 kb to 50 to 100 kb and then to 0.5 to 1 Mb, respectively. The LD estimates decreased as the distance increased in SNP pairs, and increased with the increase of minor allelic frequency (MAF) and with the decrease of sample sizes. Estimates of effective population size for Chinese beef Simmental cattle decreased in the past generations and $N_e$ was 73 at five generations ago.

• International Journal of Industrial Entomology and Biomaterials
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• v.35 no.1
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• pp.30-38
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• 2017

The red-spotted apollo butterfly, Parnassius bremeri Bremer, 1864 (Lepidoptera: Papilionidae), is an endangered species in South Korea. Development and application of molecular markers to assess population genetics perspectives can be used as a basis to establish effective conservation strategies. In this study, we developed 12 microsatellite markers specific to P. bremeri using Illumina paired-end sequencing and applied the markers to South Korean populations to understand population characteristics. Genotyping of 40 P. bremeri individuals from three localities showed that at each locus, the observed number of alleles ranged from 6 to 22 and the observed and expected heterozygosities were 0.500-1.00 and 0.465 to 0.851, respectively. Significant deviation from the Hardy-Weinberg equilibrium was not observed in all loci studied. The population based $F_{ST}$ and $R_{ST}$ collectively suggest that at least the Samcheok population in northernmost Gangwon Province has a significant divergence from the remaining two populations (P < 0.01), and this result is also reflected in the forewing length. Further studies with an increased sample size will be necessary to draw robust conclusions and devise conservation strategies.

• International Journal of Industrial Entomology and Biomaterials
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• v.37 no.1
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• pp.1-8
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• 2018

The nerippe fritillary butterfly, Argynnis nerippe, is listed as an endangered species in Korea. Establishment of effective conservation strategies can be aided by the development and application of molecular markers that can be used to investigate the population genetics of the butterfly. Therefore, in this study, we identified ten microsatellite markers specific to A. nerippe using the Next-Seq 500 platform, and applied these markers to investigate the characteristics of five South Korean butterfly populations. Genotyping of 48 A. nerippe individuals from five localities showed that at each locus the number of alleles ranged from 4 to 14, and that the observed and expected heterozygosities were 0.324-0.863 and 0.138-0.985, respectively. Significant deviation from the Hardy-Weinberg equilibrium was not observed at any locus. Population structure analysis indicated that there are two genetic groups in Korea, but no population-based gene pool assignments were found. Analysis of $F_{ST}$, $R_{ST}$, and a principal coordinates analysis suggested that the Gureopdo and Yaecheon populations were isolated from other populations. Genetic isolation of the Gureopdo population may be a consequence of unequal population change between Gureopdo and inland populations and to the offshore habitat of Gureopdo. Genetic isolation of the Yaecheon population may be a consequence either of the southernmost location of the population or of the limited sample size available. Further studies with increased sample sizes will be necessary to draw robust conclusions on population isolation and to devise conservation strategies.