• Transactions of the Korean Society of Mechanical Engineers B
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• v.41 no.3
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• pp.211-219
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• 2017

In this study, we performed numerical simulations on a circulating air classifier using a commercial computational fluid dynamics program. The variations in the grade efficiency, the cut-size and the cut-sharpness were calculated and discussed. By controlling the rotating speed of the main fan, the cut-size could be rapidly increased. However the linearity of the cut-size variation with respect to the main fan speed was not sufficient for application to contaminated soil classification processes. On the other hand, by varying the rotating speed of the classifying fan, the cut-size gradually decreased and could be precisely adjusted. Using both the main fan and the classifying fan, we could achieve larger cut-sharpness values and better classifying performances.

• Journal of the Korean Geographical Society
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• v.36 no.3
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• pp.217-232
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• 2001

One of the molt debatable Issues on geomorphological study in Korea should be the discussion over the formation process of gent1e slope surfaces on the piedmont area. In this study, the characteristics of spatial distribution and the formation process of geomorphic surfaces were investigated by classifying the alluvial fans as three geomorphic surfaces alluvial the Bulguksa fault-line The fan surfaces, distributed along the west slue of Bulguksa Mts, consists the confluent alluvial fans continuously along the N-S direction The surfaces of Sincheon-Hyomun district juxtaposed to the Ulsan Bay must be infulenced by sea-level chance during the Quaternary Taken together, these observation suggests that the major four factors contributed to the fan formation 1) rather longer freeze-and-thaw cycle during the Glacial period. 2) the steep mountain slope along the west side of Bulguksa Mts.. which had been resulted from the horizont stress of EAst Sea 3)the tectolinear fault system developed by structural movement along the Bulguksa Fault-line valley. and 4) the erosion-labile characteristics of bedrock In this urea which is consisted of the Bulguksa granite and the sedimentary rock formed in Cretaceous period.

• Journal of architectural history
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• v.18 no.1
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• pp.31-49
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• 2009

Periodically, the Japanese Castle was created in the domestic of Japan and then 2 Invasions into Chosun was started. The Japanese Castle in the domestic of Japan was repaired several times by the building boom of castle before & after 2 invasions and so the initially-built type of castles was changed. Accordingly, there are much difficulties to understand the original shape of Japanese Castle. Through the Japanese Castle within Korea called as the fossil of Japanese Castle, I would like to examine & consider its building period and characteristics. The terminology called as [Two Side Stone's Wall] is that of castle which is not acknowledged in the Japanese Academic Circles. However, it means the two-fold wall of Japanese Castle which was widely applied to the fortification way in the Age of Japan Edo. The terminology of [Sori] says the stonework curve in the corner of Japanese Castle which is indicated best in the Japanese Castle. It calls the curve as like the fan frame. [Curb Stone's Wall] says the type of castle wall constructed with over 1 face in wall body of Japanese Castle. (1) About classifying the construction period of Japanese Castle, the curb stone's wall and the castle having no two side stone's wall must consider the building period as that of Japanese Invasion of Korea in 1592. If there was [Sori], the two-side stone's wall was used and the place which supported the documentary data, in particular, the place having the record of contraction is considered to be confirmed as the castle constructed in the period of Japanese Invasion of Korea in 1597. (2) The two-side-type stone's wall shown in the Modern Japanese Stone Castle is difficultly considered to be generated from the Japanese Castle at the period of Japanese Invasion of Korea in 1592 and in 1597. (3) The beautiful [Sori] shown in the Modern Japanese Stone Castle was started from the Japanese Castle of Korea at the period of Japanese Invasion of Korea in 1597. It is difficultly considered which its indication was firstly generated by the Chaesung-Folded Segment Structure.