• Journal of Preventive Medicine and Public Health
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• v.38 no.2
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• pp.147-153
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• 2005

Objectives: Studies on the geographical differences in mortality tend to use a census population, rather than a registration population, as the denominator of mortality rates in South Korea. However, an administratively determined registration population would be the logical denominator, as the geographical areas for death certificates (numerator) have been determined by the administratively registered residence of the deceased, rather than the actual residence at the time of death. The purpose of this study was to examine the differences in the total number of a district population, and the associated district-specific mortality indicators, when two different measures as a population denominator (census and registration) were used. Methods: Population denominators were obtained from census and registration population data, and the numbers of deaths (numerators) were calculated from raw death certificate data. Sex- and 5-year age-specific numbers for the populations and deaths were used to compute sex- and age-standardized mortality rates (by direct standardization methods) and standardized mortality ratios (by indirect standardization methods). Bland-Altman tests were used to compare district populations and district-specific mortality indicators according to the two different population denominators. Results : In 1995, 9 of 232 (3.9%) districts were not included in the 95% confidence interval (CI) of the population differences. A total of 8 (3.4%) among 234 districts had large differences between their census and registration populations in 2000, which exceeded the 95% CI of the population differences. Most districts (13 of 17) exceeding the 95% CI were rural. The results of the sex- and age-standardized mortality rates showed 15 (6.5%) and 16 (6.8%) districts in 1995 and 2000, respectively, were not included in the 95% CI of the differences in their rates. In addition, the differences in the standardized mortality ratios using the two different population denominators were significantly greater among 14 districts in 1995 and 11 districts in 2002 than the 95% CI. Geographical variations in the mortality indicators, using a registration population, were greater than when using a census population. Conclusion: The use of census population denominators may provide biased geographical mortality indicators. The geographical mortality rates when using registration population denominators are logical, but do not necessarily represent the exact mortality rate of a certain district. The removal of districts with large differences between their census and registration populations or associated mortality indicators should be considered to monitor geographical mortality rates in South Korea.

• Journal of the Korean Geographical Society
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• v.43 no.3
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• pp.337-357
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• 2008

This study examines the characteristics of population ageing and the employment of aged workers in Seoul. Population indexes such as aged/child ratio and longevity degree are analyzed to identify the time-spatial changes and differentiation of population ageing by Gu. Job offerers, job seekers and employees related to the aged workers are also analyzed using data from Center of Job Placement for the Aged in Seoul. The results indicate that population ageing of Seoul has progressed faster than other regions in recent years. In addition, regional differences in tendency of population ageing is obvious even within Seoul. The percentage of unskilled laborer is much higher in Seoul compared with other regions. There is geographical differentiation in employment of aged workers among regions within Seoul. The employment opportunity of the aged is high in core economic areas of Seoul, while low in the outer residential area. This shows geographical mismatch between job offerers and seekers, which means that it is difficult for aged workers to get the jobs near to their residence. Accordingly, governmental support and intervention is needed considering their lower mobility.

• The Korean Journal of Community Living Science
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• v.15 no.2
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• pp.137-150
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• 2004

The aged population in Korea, especially in rural areas, has been growing rapidly. The welfare for the rural elderly has become a major concern, however we don't have enough information about that population; we don't even have detailed demographics of it. The present research is aimed at; 1) investigating the tendency and changing geographical distributions of the rural elderly, and 2) introducing GIS(Geographic Information Systems) as a useful tool in analyzing geographical distributions of the aged. The General Census Data from 1960 to 2000 was used to carry out this study. The major findings are; 1) There has been a gradual decrease in the rural population over the past 40 years, but this tendency has slowed down more recently; 2) It was observed that the 'oldest-old' group aged 85 years old and over has actuality increased in rural areas faster than any other age group; 3) The changing patterns of the elderly population were different in metropolitan areas and rural areas. In brief, there are far more aged people, especially of the 'oldest-old' group and females in rural areas than those in urban areas. These population, the 'oldest-old' or females, are the most vulnerable and have the greatest need for social welfare and social services of different kinds.

• Journal of fish pathology
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• v.19 no.2
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• pp.141-153
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• 2006

Genomic DNA samples isolated from two geographical crayfish (Cambaroides similis) populations in the inland of the Korean Peninsula, at Jeonju (Jeonju crayfish; JJC) and Jeongup (Jeongup crayfish; JUe), were PCR-amplified repeatedly. The six arbitrarily selected primers OPC-03, OPC-06, OPC-09, URP-02, URP07 and URP-09 generated the common, specific, and polymorphic fragments. The sizes of DNA fragments also varied widely, from 100 bp - 2,600 bp. Here, 521 fragments were identified in the JJC population, and 354 in the JUC population: 6 primers generated 60 specific fragments (60/521 fragment, 11.5%) in the JJC population, and 90 (90/354 fragments, 25.4%) in the JUC population. These primers produced 42 polymorphic fragments (8.1%) in the DC population, and 18 (5.1%) in the mc population. Especially these results demonstrate that the primers detected numerous specific fragments. Especially, the decamer primer OPC-06 generated inter-population-common DNA fragments, approximately 400 and 800 bp, respectively, in both the JJC and JUC populations. The universal primer URP-02 also generated inter-population-identical DNA fragments, approximately 350 bp and 600 bp, between the two geographical crayfish populations. Based on the average bandsharing values of all samples, the bandsharing value of individuals within the JJC population was much higher than in the JUC population. The bandsharing value between individuals no. 10 and no. 15 was 0.683, which was the highest between the two geographical populations. The dendrogram obtained by the six primers indicates two genetic clusters: cluster I (CRAYFISH 01 - CRAYFISH II), and cluster 2 (CRAYFISH 12 - CRAYFISH 22). The genetic distance between the two geographical populations ranged from 0.053 to 0.605. Ultimately, the longest genetic distance displaying significant molecular differences was found to exist between individuals in the two crayfish populations, between individuals CRAYFISH no. 02 of Jeonju and CRAYFTSH no. 15 of Jeongup (genetic distance = 0.605).

• The Korean Journal of Malacology
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• v.25 no.1
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• pp.5-13
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• 2009

Genomic DNA isolated from two geographical ark shell (Scapharca subcrenata) populations was amplified several times by PCR reactions. The ark shell population from Daecheon (ASPD) and from Wonsan (ASPW) in the West Sea and the East Sea of Korean Peninsula, respectively, obtained. The seven arbitrarily selected primers OPA-05, OPA-11, OPB-09, OPB-11, OPB-14, OPC-18 and OPD-07 were shown to generate the loci observed per primer, shared loci by each population, specific loci, unique shared loci to each population and shared loci by the two populations which could be clearly scored. Here, 862 loci were identified in the ASPD population, and 1,191 in the ASPW population: 137 specific loci (15.9%) in the Daecheon population and 84 (7.1%) in the Wonsan population. 407 shared loci by each population, with an average of 58.1 per primer, were observed in the ASPD population. 473 shared loci by each population, with an average of 67.6 per primer, were identified in the ASPW population. The numbers of specific loci in the ASPD and ASPW population were 137 and 84, respectively. Consequently, the average bandsharing value of individuals within the ASPW population was much higher than in the ASPD population. The bandsharing value between individuals' no. 08 and no. 13 was 0.628, which was the highest measured between the two geographical populations. The dendrogram obtained by the seven primers indicated three genetic clusters: cluster 1 (DAECHEON 01-DAECHEON 11), cluster 2 (WONSAN 12 and 14) and cluster 3 (WON SAN 13, 15, 16, 17, 18, 19, 20, 21 and 22). The genetic distance between the two geographical populations ranged from 0.043 to 0.499. Especially, individual no. 10 of Daecheon population was most distantly related to no. 14 of Wonsan population (genetic distance = 0.499).

• Journal of the Korean Geographical Society
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• v.38
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• pp.61-74
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• 1988

Changing patterns of population densities in urban centers are different between Western countries and non-Western countries. Although Seoul is located in a non-Western country, the result of this study shows that its pattern of population density falls into the category of Western cities. Through the examination of three population density gradient models, it is clear that no model can precisely explain the population distribution of Seoul over time. Some of the models partly indicate the actual population distrisbution. The Clark model is appropriate to denote population distribution in the center of Seoul at an early stage in development. The Sherratt model cannot adequately explain the population distribution of Seoul.

• Journal of the Korean Geographical Society
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• v.30
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• pp.14-27
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• 1984

• Journal of the Korean Geographical Society
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• v.32
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• pp.39-57
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• 1985

• Development and Reproduction
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• v.19 no.4
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• pp.259-264
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• 2015

Genomic DNA samples isolated from geographical purplish Washington clam (Saxidomus purpuratus) were obtained from three different regions in the Korean Peninsula: Geoje (Geoje population; GJP), Gunsan (Gunsan population; GSP) and a site of North Korea (North Korea population; NKP). The seven primers generated the total 369 loci that can be scored from the GSP clam population. 356 fragments were generated from the NKP clam population. The complexity of the banding patterns varies dramatically between the primers and three localities. In this study, 319 loci were identified in the purplish Washington clam from Geoje and 369 in the clam population from Gunsan: 221 specific loci (69.3%) in the GJP clam population and 300 (81.3%) in the GSP population. These results demonstrate that the primer detected a large quantity of specific fragments, suggesting that the genetic variation in the GSP is higher than in the GJP population. In particular, the BION-28 primer gave DNA profiles with more fragments than the other six primers in the NKP population. The oligonucleotides primer BION-75 produced 21 unique loci to each population, which were ascertaining each population, approximately 250 bp, 300 bp and 400 bp, in the GJP population. Outstandingly, the primer BION-50 detected 21 shared loci by the three populations, major and/or minor fragments of sizes 150 bp, which were matching in all samples. With regard to average bandsharing value (BS) results, individuals from GJP population (0.743) displayed higher bandsharing values than did individuals from GSP population (0.606). In the present study, the dendrogram gained by the seven oligonucleotides primers indicates three genetic clusters: cluster 1 (GEOJE 01 ~ GEOJE 07), cluster 2 (GUNSAN 08 ~ GUNSAN 14), cluster 3 (N.KOREA 15 ~ N.KOREA 21). Among the twenty one clams, the shortest genetic distance that revealed significant molecular differences was between individuals 08 and 09 from the NKP population (genetic distance = 0.073), while the longest genetic distance among the twenty-one individuals that demonstrated significant molecular differences was between individuals GEOJE no. 03 and GUNSAN no. 09 (genetic distance = 0.669). Comparatively, individuals of GJP population were properly closely related to that of NKP population, as revealed in the hierarchical dendrogram of genetic distances. In due course, PCR analysis has revealed the significant genetic distance among three purplish Washington clam populations. PCR fragments discovered in this study could be valuable as a DNA marker of the three geographical clam populations to distinguish.

• The Korean Journal of Malacology
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• v.22 no.2
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• pp.97-108
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• 2006

Genomic DNA samples isolated from geographical purple Washington clam (Saxidomus purpuratus) were obtained from two different regions in Korean Peninsula: Gunsan (Gunsan population; GSP), and Haeju (Haeju population; HJP), a collection area in the vicinity of the West Sea. The seven arbitrarily primers, OPA-07, OPA-09, OPA-18, OPA-20, OPC-03, OPC-06 and OPC-09 were shown to generate the total loci, loci observed per primer, shared loci by each population, specific, and polymorphic loci which could be clearly scored. We also generated the unique shared loci to each population and shared loci by the two populations in purple Washington clam. The size of the DNA fragments also varied wildly, from 50 to 2,400 bp. Here, 304 total loci were identified in the GSP purple Washington clam population, and 282 in the HJP: 91 polymorphic loci (29.9%) in the GSP and 47 (16.7) in the HJP. 198 shared loci, with an average of 28.3 per primer, were observed in the GSP population. The decamer primer OPA-07 generated the shared loci by the two populations, approximately 1,000 bp, between the two Saxidomus populations. The oligonucleotide primer OPC-03 also generated the shared loci by the two populations, approximately 500 bp and 1,000 bp, in GSP population from Gunsan and HJP population from Haeju. The other primer, OPC-06 generated the shared loci by two Gomphina populations (approximately 400 bp). The dendrogram, generated by seven reliable primers, indicates three genetic clusters. The dendrogram obtained by the seven primers indicates three genetic clusters: cluster 1 (GUNSAN 01-GUNSAN 02), cluster 2 (GUNSAN 03-GUNSAN 11), and cluster 3 (HAEJU 12-HAEJU 22). The genetic distance between the two geographical populations ranged from 0.043 to 0.506. Especially, the longest genetic distance displaying significant molecular differences, 0.506, was found to exist between individuals GUNSAN no. 11 of Gunsan and HAEJU no. 17 of Haeju.