• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.9
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• pp.765-772
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• 2015

Aerodynamic force measurements and phase-locked PIV study were carried out to check the bio-mimetic MAV applicability of a swift flight. Two-rotational DOF robotic wing model and blowing-type wind tunnel were employed. The amplitude of twist angle were ${\pm}0$, ${\pm}5$, ${\pm}10$, and ${\pm}20$ deg. and stroke angles were manipulated by simple harmonic function with out-of-phase in regards to the stroke motion. It is acknowledged that the time-varying lift coefficients in accordance with the change of the twist angle did not result in any noticeable differences, just the small decrease and delay. However, the drag exhibited that the small change of the twist angle can produce large thrust. These findings imply why a swift uses small twist angle during flight. The PIV results displayed that the delay of aerodynamic forces is highly associated with the vortical structures around the wing. It is therefore indicated that a process of designing a swift-based Micro Air Vehicle should take the twist angle into consideration, as the essential parameter.

• The Korean Journal of Ecology
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• v.25 no.3 s.107
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• pp.179-187
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• 2002

This study was conducted to clarify the characteristics of attitudinal bird communities in Mt. Seoraksan National Park from May to Oct. 2004. Marsh tit Parus palustris, Arctic warbler Phylloscipus borealis, coal tit Parus ater and Eurasian nuthatch Sitta europaea evenly distributed in almost elevational ranges. Goshawk Accipiter gentilis, black grouse Tetrao tetrix, white-lumped swift Apus pacificus, Siberian rubythroat Luscinia calliope, red-flanked bluetail Tarsiger cyanurus, dusky warbler Phylloscopus fuscatus, yellow-browned warbler Phylloscopus inornatus, siskin Carduelis spinus and rook Corvus frugilegus were only observed in high altitude area. Distribution pattern of birds in Mt. Seoraksan National Park showed differences by elevation. There was difference in attitudinal distribution pattern of birds in Mt. Seoraksan National Park. It seems that habitat preference or selection is different in each species. Attitudinal habitat preference of each bird species need further studies.

• The Korean Journal of Ecology
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• v.25 no.2
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• pp.109-117
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• 2002

This study was conducted to clarify the characteristics of attitudinal bled communities in Mt. Seoraksan National Park from May to Oct. 2001. Marsh tit Parus palustris, Arctic warbler Phylloscipus borealis, coal tit Parus ater and Eurasian nuthatchh Sitta europaea evenly distributed in almost elevational ranges. Goshawk Accipiter gentilis, black grouse Tetrao tetrix, white-rumped swift Apus pacificus, Siberian rubythroat Luscinia calliope, red-flanked bluetail Tarsiger cyanurus, dusky warbler Phylloscopus fuscatus, yellow-browned warbler Phylloscopus inomatus, siskin Carduelis spinus and rook Corvus frugilegus were only observed in high altitude area. Distribution pattern of birds in Mt. Seoraksan National Park showed differences by elevation. There was difference in altitudinal distribution pattern of birds in Mt. Seoraksan National Park. It seems that habitat preference or selection is different in each species. Altitudinal habitat preference of each bird species need further studies.

• Korean Journal of Environment and Ecology
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• v.24 no.2
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• pp.139-146
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• 2010

The survey was done in order to find what kinds of birds visit Taeanhaean National Park during breeding season, where we fixed up 10 coastal areas and islands within the National Park. Three groups concurrently performed the field research from 5th to 9th of July in 2009. Total 58 species and 7,323 individuals were recorded in Taeanhaean National Park. 48 species including 6,187 individuals were observed in coastal areas and 33 species including 1,136 individuals in island areas. The most dominant species in the National Park are Larus crassirostris which accounts for 60% of the birds inhabiting there, and they seem to have been bred in the islands near the National Park. The birds observed only around the coastal areas include Anas poecilorhyncha, Fulica atra, Egretta intermedia and the others which consist of 25 species and amount to 318 individuals, and the birds found exclusively in island areas include Phalacrocorax filamentosus, Apus pacificus¸ Locustella pleskei and other birds, which consist of 10 species and the number of those individuals observed was 308. The inhabited islands areas such as Gauido were characterized by high ratio of waterbird population, which seems to be correlated with the factors such as the extent of island, the richness of water resources, and the diversity of habitats. Based on the data collected during the research and other data from the previous observations, the kinds of dominant species remain nearly unchanged. And in spite of the oil spill accident in 2007, the increase in the number of waterbirds compared to 2004 may be the evidence that the area is recovering from the environmental pollution. At present, the tidal power plants are being built or scheduled to be built and large-scale reclamation is also under way. What is worse, those areas are seeing the increase of pension construction, which is likely to be the potential cause of damage and disturbance against some key habitats for the waterbirds. Therefore, it is a major priority that we build the bird information system to efficiently manage the knowledge-based asset collected from bird-watching groups and to better monitor the areas that need enhanced database through which the National Park can be appropriately administered.