• Journal of computational fluids engineering
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• v.13 no.4
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• pp.39-44
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• 2008

Numerical simulations of laminar flow over a sphere are conducted to investigate the effect of the Reynolds number on the characteristics of vortex shedding. The Reynolds numbers considered are between 300 and 475, covering unsteady planar-symmetric and asymmetric flows. Results show that the unsteady planar-symmetric flow can be categorized into two different regimes: single-frequency regime and multiple-frequency regime. The former has a single frequency component due to periodic shedding of the vortices with the same strength in every shedding cycle, while the latter has multiple frequency components due to cycle-to-cycle variation in the strength of shed vortices with the shedding angle fixed. The multiple-frequency planar-symmetric flow, which is newly found in the present study, occurs at Re=330${\sim}$360 between the single-frequency planar-symmetric flow and the asymmetric flow. On the other hand, the asymmetric flow occurs at Re${\geq}$365, where the vortices shed from the sphere show variation both in strength and shedding angle unlike the planar-symmetric flow. Also, it is shown that the breaking of planar symmetry is closely related to the imbalance of vortical strength between a pair of streamwise vortices.

• Korean Institute of Interior Design Journal
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• v.22 no.6
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• pp.140-150
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• 2013

The weaving of Mosi(fine ramie) in the Hansan region was inscribed on the representative list of the UNESCO intangible cultural heritage in 2011. Unlike other fabric, as the Mosi is very sensitive towards humidity it needs different conditions for its workspace. The Hansan region is near the sea with many mountains around where it is easy for the Mosi to grow and is an appropriate place to weave Mosi. Recently the manpower for weaving of Mosi in the Hansan area is decreasing with the decrease of workspace drastically. After the investigation of workspace for the weaving of Mosi in the Hansan area, most of the places were done in individual houses and it could be classified in 1. Mosi storeroom, 2. Shed(Gwang che), 3. Dugout hut, 4. Under the toenmaru The depth of the dugout hut and under the toenmaru is around 80~60cm which is similar with the depth of the prehistoric dugout hut houses. The towns for weaving of Hansan Mosi are formed mostly in the Seochungun district, but the Hoamri Hansan-myeon and Gayangri Masan-myeon has the most traditional workspaces and they are still forming and maintaining the traditional town composition. However the numbers are too small and maintaining the traditional town is getting more difficult, so a plan for the maintenance should be made to continue to keep it as UNESCO intangible cultural heritage.

• Asian-Australasian Journal of Animal Sciences
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• v.6 no.3
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• pp.389-394
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• 1993

A study on housing and management of dairy cows was conducted in three villages. All activities of husbandry related to the housing and the condition of the cows were observed and farmers were interviewed using a questionnaire. The main type of housing was a tie stall mostly in the back yard area with a gable or shed type roof. Inside the shed the temperature ranged from 17 to $29^{\circ}C$ and the relative humidity ranged from 62 to 73%. Drainage and manure handling was poor which lead to poor cleanliness of the stables and animal skins. The floor space was mostly wide and the roof level was low (less than 2.5 m). The slope of the floor (1-3%) was sufficient, the roughness of the floor was of medium quality. The shape and size of the feed trough was good with a surface of mostly irregular forms. Concentrate was mixed with water and offered in liquid form in pails made from plastic or from parts of rubber car tires. Hoof length was too long which could lead to unstable position and self injury. It is concluded that the housing conditions of dairy cattle need to be improved in order to improve the condition of the animals and the production performance.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.4
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• pp.633-641
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• 1999

Reaction by neighbours to odours is increasingly affecting operations of existing animal farming operations and may adversely constrain the further development of the animal production industry in some parts of Australia. It is critical that the scale of such odour impact on the rural-urban interface be estimated to provide useful information both for environmental protection and animal farming operations. Furthermore, the information can be used to modify odour reduction strategies as economic conditions change. The Centre for Water and Waste Technology at The University of New South Wales has developed a comprehensive set of odour control techniques in the course of its research and development effort over the past eight years. Techniques have been developed for odour sampling at point, area and volume sources, monitoring environmental parameters such as ventilation rate, shed temperature, shed humidity, litter water content and ambient meteorological condition, olfactometry and odour dispersion modelling. The work has paved the way for the establishment of odour reduction strategies based on best environmental management practice and advanced odour abatement technologies.

• Journal of Ecology and Environment
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• v.31 no.3
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• pp.207-211
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• 2008

We investigated the leaf demography of a temperate woody liana, Akebia trifoliata, in a temperate forest in Japan, Akebia is semi-evergreen: some leaves are shed before winter, while others remain through the winter. Previous studies of semi-evergreen species found that variation in leaf life span was caused by variation in the timing of leaf emergence, Leaves that appeared just before winter over-wintered, while leaves appearing earlier were shed, However, it is unclear whether leaves of the same cohort (i.e., leaves that appear at the same time within a single site) show variation in life span under the effect of strong seasonality. To separate variation in life span among the leaves in each cohort from variation among cohorts, we propose a new method - the single leaf diagram, which shows the emergence and death of each leaf. Using single leaf diagrams, our study revealed that Akebia leaves within a cohort showed substantial variation in life span, with some over-wintering and some not. In addition, leaves on small ramets in the understory showed great variation in life span, while leaves on large ramets, which typically reach higher positions in the forest canopy, have shorter lives, As a result, small ramets were semi-evergreen, whereas large ramets were deciduous, The longer lives of leaves on small ramets can be interpreted as a shade-adaptive strategy in understory plants.

• Journal of KSNVE
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• v.6 no.5
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• pp.661-669
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• 1996

Proposed is an aero-acoustic performance prediction method of axial fan. The fan aerodynamic performance is predicted by combining pitch-averaged quasi 3-D flow analysis with pressure loss models for blade boundary layer and wake, secondary flow, endwall boundary layer and tip leakage flows. Fan noise is assumed to be radiated as dipole distribution type, and its generation is assumed to be mainly due to the vortex street shed from blade trailing edge. The fluctuating pressure and lift on the blade surface are analyzed by incorporating the wake vortex stree shed from blade trailing edge. The fluctuating pressure and lift on the blade surface are analyzed by incorporating the wake vortex street model with thin airfoil theory. The aero-acoustic performance prediction results by the present method are in good agreement with the measured results of several axial fans. With the present prediction method, parametric studies are carried out to investigate the effects of blade chord length and spacing on the efficiency and the noise level of fan. In the case of lightly loaded fan, both efficiency improvement and noise reduction can be achieved by decreasing chord length or by increasing blade specing. However, when fan is designed at highly loaded condition, the noise reduction by increasing blade spacing penalizes the attaninable efficiency of fan.

• Journal of the Korean Society of Visualization
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• v.3 no.2
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• pp.63-70
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• 2005

Birds and insects flap their wings to fly in the air and they can change their wing motions to do steering and maneuvering. Therefore, we created various wing motions with the parameters which affected flapping motion and evaluated the aerodynamic characteristics about those cases in this study. As the wing rotational velocity was fast and the rotational timing was advanced, the measured aerodynamic forces showed drastic increase near the end of stroke. The mean lift coefficient was increased until angle of attack of $50^{\circ}$ and showed the maximum value of 1.0. The maximum mean lift to drag ratio took place at angle of attack of $20^{\circ}$. Flow fields were also visualized around the wing using particle image velocimetry (PIV). From the flow visualization, leading-edge vortex was not shed at mid-stroke until angle of attack of $50^{\circ}$. But it was begun to shed at angle of attack of $60^{\circ}$.

• Korean Journal of Veterinary Service
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• v.15 no.2
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• pp.109-120
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• 1992

330 Samples of the slaughtered cattle heart muscle were collected from the abattoirs of five regions in Kangwon - do to reveal the frequency of sarcocystis infections during January through December in 1991. The samples were inspected for bradyzoites by the trypsin digestion technique and the possitive samples were fed to dogs and cats for the detection of sporocysts shed in the feces. The results obtained were summarized as follows : 1. The infection rate of bovine Sarcocystis investigated from 330 samples was 43.6%. 2. It revealed that the infection rate of Sarrocystis increased gradully with the advance in the age, 14.5% in below two years, 26.1% in the three years, 30% in four years, 54.7% in five years, 74.4% in six years, 90% in seven years and 100% in older than eight years. 3. The cyst walls detected out from the heart muscles were less than l${\mu}{\textrm}{m}$ in thickness and the size of bradyzoites were $11.8{\times}2.8{\mu}m$ in average. 4. The size of sporocysts shed in the feces of dogs were $15.8{\times}9.8{\mu}m$ in average and the prepatent periods ranged from 12 to 16days. 5. Sarcorystis found in the bovine heart muscles were identified as Sascocystis cruzi ( Hasselman, 1923) , wenyon, 1926.

• Journal of Chest Surgery
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• v.26 no.2
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• pp.108-114
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• 1993

The risks of homologous blood transfusion are well documented and recently increased with the emergence of acquired immunodeficiency syndrome. This is a report concerning 29 consecutive adult with no blood conservation patients (Group I) who had an elective cardiac operations. A similar group of 29 patients operated on 1992 but with blood conservation (Group II). In I of Group I patients and 15 of Group II patients, no homologous blood products were required. Group II patients used significantly less fresh frozen plasma (2.05${\pm}$0.68 unit versus 6.52${\pm}$0.72 unit, p<0.05) and the homologous blood transfusion (0.42${\pm}$0.9 unit versus 3.64${\pm}$0.17 unit, p<0.05) than Group I patients. Group II patients had also significantly less postoperative bleeding (338${\pm}$39.9 ml versus 585${\pm}$93.0 ml, p<0.05) than Group I patients. Group II patients recieved 460${\pm}$62.6 ml of mediastinal shed blood in acquired group. In conclusion, a simple and inexpensive blood conservation program, mainly combining autologous blood removal before bypass, retransfusion of the volume remaining in the oxygenator, and consistent autotransfusion of mediastinal shed blood has enabled us to avoid infusion of homologous blood in 15/29 patients of Group II patients. No side effects or complicatinos could be related to the blood conservation program.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.05a
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• pp.512-512
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• 2000

Some planorbid snails such as Hippeutis cantori and Segmentina hemisphaerula have reported as the molluscan intermediate hosts of Neodiplostomum seoulense, one of important snail-borne human intestinal trematodes in Korea. However, one of the Korean lymnaeid snail species, Austropeplea ollular was also found to be the first intermediate ho of N. seoulense. In field-collected Austropeplea snails from Sorae and Kimpo out of se collected localities, the bifurcated cercariae of N. seoulense were shed (infection rat 0.3%), whereas no Radix auricularia and Fossaria truncatula were found shedding cercariae. Each of 12 tadpoles of Rana nigromaculata, known as the second intermedia host of N. seoulense, were exposed to 200 cercariae shed from field-collected A ollula. F tadpoles of R. nigromaculata were found to be massively infected with metacercariae o N. seoulense (recovery rate: 62.1%). Each of five rats (Sprague-Dowley strain) was or fed with 200 metacercariae, and eggs of N. seoulense were detected in the rat feces on week later. These rats were killed 4 weeks after postinfection and adult worms of N seoulense were recovered from the small intestines (recovery rate: 9%). This is the f report of A. ollula as the first molluscan intermediate host for N. seoulense in Korea.