• Journal of Advanced Marine Engineering and Technology
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• v.30 no.2
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• pp.296-303
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• 2006

Recently, micro hydropower attracts attention because of its clean. renewable and abundant energy resources to develop. However, suitable turbine type is not normalized yet in the range of micro hydropower and it is necessary to study for the effective turbine type. Moreover, relatively high manufacturing cost by the complex structure of the turbine is the highest barrier for developing the micro hydropower turbine. Therefore a cross-flow turbine is proposed for micro-hydropower in this study because of its simple structure and high possibility of applying to low head. The purpose of this study Is to further optimize the turbine structure and improve the performance. A guide vane is removed and the runner chamber is made compact using a new air supply method. The results show that the efficiency of the turbine is improved in a wide operating range and the size of the turbine is remarkably reduced.

• The Korean Journal of Archival Studies
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• no.17
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• pp.3-37
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• 2008

In this article, I outlined the archival management system in Early Joseon Dynasty and examined the characteristics of the system. At first, I explained the three aspects of the archival management; the memory of the past, the documentation of the contemporary, and the vision of the future through the documentation. Secondly, I tried to understand the character of the Veritable Record and its compilation by the concepts of archival science such as 'authenticity', 'reliability'. In the memory of the past, the History of a Dynasty(Koryo-Sa) and the Comprehensive History of Eastern Kingdom were included. The arrangement of the past was accompanied with the systematic study of the domestic and foreign histories. At the beginning of the state building, there was many practical need to the experiences of government and social re-construction. It was also the process of the legitimacy establishment of the new dynasty. And the Bureaucracy promoted the development of the records and archival management system because it needed the continuity and evidence of business. The dualistic structure of the records and archival management system was the most unique character of this age. The management of general administrative records was not different from the modern one. But the historical drafts and the compilation of Veritable record were different. Here, I had to examine the characteristics of these procedures by the concept authenticity, reliability, and custodianship. In doing so, I suggested the need of conceptualization of the historical terms such as 'the primary sources' and 'the secondary sources' in historical study. The archival concepts will be the most useful means to that issue. Through the memory of the past and the documentation of the contemporary, they made visions of the future, new vision of the Literati Governance. In this tradition, in spite of the revision of the Veritable records by the new changed political party, both the orignal and the revised remained as the comparative evidence for the future generation in the name of the Black-Red Revised History.