• Journal of Environmental Policy
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• v.2 no.2
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• pp.1-16
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• 2003

This paper focuses on examining environmental implications embedded in recent spatial expansion of the Asian megacities as well as exploring the potentials of planning practices in addressing urban environmental problems. Regardless what underlying forces of recent metropolitan expansion are, nearly all the Asian megacities suffer serious environmental problems as these cities rapidly grow in terms of population and geographical boundaries. Furthermore, the global environmental implication of urban expansion at Asian megacities implies that there must be intense endeavor to develop more innovative policy solution in order to tackle down the worsening urban environmental problems in Asian cities at a metropolitan scale. Given the situation that there has been little attention on environmental consequence of the Asian metropolitan expansion in spatial term, this paper presents the overview on the changing nature of urban environmental problems embedded in the spatial expansion of recent metropolitan area in Asia, along with exploring possible solutions from planning practices guiding sustainable urban development in Asia.

• Animal Systematics, Evolution and Diversity
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• v.28 no.4
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• pp.279-290
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• 2012

Plecoglossus altivelis (ayu) is an amphidromous fish widely distributed in Northeastern Asia from the East China Sea to the northern Japanese coastal waters, encompassing the Korean Peninsula within its range. The shore lines of northeastern region in Asia have severely fluctuated following glaciations in the Quaternary. In the present study, we investigate the population genetic structure and historical demographic change of P. altivelis at a population level in East Asia. Analysis of molecular variance (AMOVA) based on 244 mitochondrial control region DNA sequences clearly showed that as the sampling scope extended to a larger geographic area, genetic differentiation began to become significant, particularly among Northeastern populations. A series of hierarchical AMOVA could detect the genetic relationship of three closely located islands between Korea and Japan that might have been tightly connected by the regional Tsushima current. Neutrality and mismatch distribution analyses revealed a strong signature of a recent population expansion of P. altivelis in East Asia, estimated at 126 to 391 thousand years ago during the late Pleistocene. Therefore it suggests that the present population of P. altivelis traces back to its approximate demographic change long before the last glacial maximum. This contrasts our a priori expectation that the most recent glacial event might have the most crucial effect on the present day demography of marine organisms through bottleneck and subsequent increase of effective population size in this region.

• Animal Systematics, Evolution and Diversity
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• v.32 no.2
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• pp.105-111
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• 2016

The genetic structure of marine animals that inhabit the seashore is affected by numerous factors. Of these, gene flow and natural selection during recruitment have strong influences on the genetic structure of seashore-dwelling species that have larval periods. Relative contributions of these two factors to the genetic structure of marine species would be determined mainly by the duration of larval stage. The relationship between larval period and genetic structure of population has been rarely studied in Korea. In this study, genetic variations of cytochrome oxidase subunit I (COI) were analyzed in two dominant species on rocky shore habitats in the Korean peninsula: periwinkle Littorina brevicula and acorn barnacle Fistulobalanus albicostatus. Both species are not strongly structured and may have experienced recent population expansion. Unlike periwinkle, however, barnacle populations have considerable genetic variation, and show a bimodal pattern of mismatch distribution. These results suggest that barnacle populations are more affected by local adaptation rather than gene flow via larval migration. The bimodal patterns of barnacle populations observed in mismatch distribution plots imply that they may have experienced secondary contact. Further studies on seashore-dwelling species are expected to be useful in understanding the evolution of the coastal ecosystem around Korean waters.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.8
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• pp.1048-1052
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• 2011

The Chinese Holstein cattle breed, an introduced breed in China, has been crossbred with native cattle breeds. We hypothesised that the Chinese Holstein local population in Beijing share haplotypes with native Asian cattle breeds, the result of a sudden population expansion in the recent past. We also hypothesised that crossbreeding and population expansion left traces that shaped the genetic makeup of the breed. Evaluation of this was performed by mitochondrial DNA (mtDNA) sequence analysis of Chinese Holstein cattle from Beijing (n = 41) and a comparison of them with the published mtDNA sequences (n = 293) of 14 Asian breeds with an emphasis on Chinese native cattle breeds. Three shared common haplotypes between Chinese Holstein cattle and native Asian cattle were found. Moreover, a high level of haplotype diversity in Chinese Holstein cattle (h = 0.9557) and low nucleotide diversity (${\pi}$ = 0.0052) was found, indicating a past population bottleneck followed by rapid population growth. These findings are supported by the significantly negative deviation of Tajima's D (-1.82085), the star-like pattern of dominant haplotypes and the pairwise mismatch distribution analysis, which showed a unimodal pattern.

• Fisheries and Aquatic Sciences
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• v.14 no.1
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• pp.16-21
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• 2011

The genetic diversity and population genetic structure of thread-sail filefish, Stephanolepis cirrhifer (Temminck & Schlegel), were examined with a nucleotide sequence analysis of a 495bp fragment of the 5'-end of the cytochrome b gene in 113 fish collected from five populations from the south and east coasts of the Korean Peninsula. Seventeen variable nucleotide sites and 16 haplotypes were defined. The observed haplotypes had a shallow haplotype genealogy and no geographical association. Most of the populations had high haplotype diversity and low nucleotide diversity, and significant negative values for Fu's $F_S$, suggesting rapid, recent population growth from an ancestral population and sudden population expansion. The estimated pairwise fixation indices ($F_{ST}$) indicate that substantial gene flow occurs among these populations. Thread-sail filefish in the South Sea of Korea and East Sea Korean populations forms a single panmictic population. Thus, thread-sail filefish in these areas should be treated as one management unit.

• Fisheries and Aquatic Sciences
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• v.15 no.1
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• pp.49-56
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• 2012

Genetic variation in the Asian shore crab Hemigrapsus sanguineus was determined from partial mitochondrial DNA (mtDNA) sequences of the cytochrome b (Cytb) gene. Samples included 143 crabs from six localities along three coastlines in South Korea. A nucleotide sequence analysis revealed 38 variable sites in a 470-bp sequence, which defined 37 haplotypes. The haplotypes were not associated geographically and had a shallow genealogy. Pairwise $F_{ST}$ tests and a two-dimensional scaling analysis revealed no significant genetic differentiation among most of the populations. The low pairwise comparison values, but significant genetic differentiation of a northeastern population from all other populations, might have been influenced by a restriction in gene flow caused by hydrographic conditions such as ocean boundaries. The high haplotype diversity, low nucleotide diversity, and time since H. sanguineus expansion in Korean coastal waters indicate rapid population growth and a recent, sudden expansion in the Late Pleistocene.

• Animal cells and systems
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• v.15 no.3
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• pp.243-249
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• 2011

The genetic diversity and population history of the Asian shore crab, Hemigrapsus sanguineus, were investigated with a nucleotide sequence analysis of 536 base pairs (bp) of the mitochondrial cytochrome c oxidase subunit I gene (COI) in 111 samples collected from four populations in Korea and one in Japan. In total, 28 haplotypes were defined by 27 variable nucleotide sites in the COI region examined. The observed haplotypes had a shallow haplotype genealogy and no geographical associations. Most of the populations had high haplotype diversity (0.656-0.788) and low nucleotide diversity (0.00165-0.00244), and significant negative values for Fu's $F_S$, suggesting rapid and recent population growth from an ancestral population and sudden population expansion. The pairwise fixation indices ($F_{ST}$) estimated with the exact test and the migration rates indicate that substantial gene flow occurs among these populations as a result of sea currents, except between the Yellow Sea coast of Korea (BUA) and the Pacific Ocean coast of Japan (JPA). These two populations (BUA and JPA) showed significant genetic differentiation and low migration rate.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.685-686
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• 2015

The world is currently undergoing an intense urbanization process. The percentage of urban dwellers has never been so high. In 2010, and for the first time, urban population surpassed the rural one, accounting for 51% of global population, and this trend will continue in the forthcoming years. This increment in concentration of population and supporting assets in cities, make their performance a critical issue for world population. Recent events such as Fukushima tsunami and the hurricane Katrina have shown how fragile built environments are and the unpredictability of occurrence and magnitude of the hazards. Such an expansion of the world's urban population, together with an increase in severity and number of hazards and catastrophes, has put under the spotlight the necessity to build cities not only sustainable, but resilient. Decision makers should acknowledge failure as an option, and the importance of developing city resilience. This paper will provide an initial review on urban resilience, definitions and assessment approaches as a first step for decision makers to account for resilience in their decision making process.

• Land and Housing Review
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• v.2 no.2
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• pp.93-99
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• 2011

Urban agriculture is drawing people's attention along with environmental problems and recent changes in population and society such as the expansion of the aged, and various related discussions are going on for expanding the base. The purpose of this study was to suggest the application of urban agriculture in the permanently rental apartment complex to build a social welfare. Aiming at the introduction of urban agriculture in permanently rental apartment complexes, this study presented the roles and necessities of urban agriculture in response to environmental changes at home and overseas, explained the current state of permanently leased apartment complexes, estimated the land area usable for urban agriculture in existing complexes, and proposed strategies for the introduction of urban agriculture.

• Korea journal of population studies
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• v.26 no.2
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• pp.111-145
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• 2003

This paper attempts to explore recent socio-demographic changes of the ethnic Korean population in Yanbian autonomous prefecture. Due to rapid decrease in the level of fertility and population ageing, Korean minority society in China has been in a process of profound transition after the introduction of the market economy and establishment of diplomatic relations between South Korea and China. The changes in demographic behaviors and in the structure of population appear to be much faster among Koreans than Hans. Results from the 2000 population census reveal that the Korean population in Yanbian, where ethnic Koreans are most densely populated in China, has been in a decreasing trends in absolute numbers and in its proportion to the total population. The growing tendency of regional mobility for work and for marriage, rapid expansion of residential areas, serious crisis of ethnic schools of Korean community, and weakening social integration and ethnic identification of Koreans in Yanbian are discussed in this study. It is expected that socio-demographic transition of Korean society in Yanbian will be even more drastic over the coming decades. The rapid changes in demographic behaviors and in the structure of population has major consequences and implications for every sphere of human life, and will present enormous challenges for the status of Korean minority society in China. Along with various statistical data on Yanbian, micro-level data as well as published reports from the 1990 Chinese population census for Yanbian and the 2000 Chinese population census are analyzed in this study. In addition to sex ratios and age ratios, various indices are calculated to analyze the characteristics and accuracy of the data from the 1990 and 2000 population censuses of China.