• Journal of the Korean Geographical Society
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• v.42 no.4
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• pp.601-615
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• 2007

Many Korean migrants in Japan have established small businesses using their ethnic networks as they were discriminated and excluded from Japanese society and labour market. The aim of this study is to explore the changes in characteristics of Korean migrants' businesses by generation, focusing on the role of co-ethnic relationships including ethnic networks and resources on their businesses. This study analyzed Korean migrants' dependence of the ethnic resources to understand the relationship between the ethnic. When Koreans first moved to Japan, laborers amounted the most, but the number of the professionals and the small business owners has increased gradually. This change was influenced by the change of generation and the improvement of education, as well as recognition of Japanese society and the change of policies toward Korean migrants in Japan. In early times when the number of small business owners started to increase, many cases such as a business, an employment, the use of Korean banks used to depend on ethnic resources. Also there were many businesses of which main customers were Koreans. However, the dependence of the ethnic resources has become diverse as the structure of the occupation has changed. The maintenance or exclusion of co-ethnic relationship depends on the structure of society and economy, and its result affect the relationship between Korean migrants in Japan and Japanese.

• Genomics & Informatics
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• v.9 no.4
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• pp.181-188
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• 2011

In planning a model-based phylogenic study for highly related ethnic data, the SNP marker number is an important factor to determine for relationship inferences. Genotype frequency data, utilizing a sub sampling method, from 63 Pan Asian ethnic groups was used for determining the minimum SNP number required to establish such relationships. Bootstrap random sub-samplings were done from 5.6K PASNPi SNP data. DA distance was calculated and neighbour-joining trees were drawn with every re-sampling data set. Consensus trees were made with the same 100 sub-samples and bootstrap proportions were calculated. The tree consistency to the one obtained from the whole marker set, improved with increasing marker numbers. The bootstrap proportions became reliable when more than 7,000 SNPs were used at a time. Within highly related ethnic groups, the minimum SNPs number for a robust neighbor-joining tree inference was about 7,000 for a 95% bootstrap support.