• Journal of the Korean Wood Science and Technology
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• v.42 no.2
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• pp.89-100
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• 2014

Energy consumption statistics in 2005 from the Korea Energy Management Corporation show that building energy usage was about 24.2% of total domestic energy consumption, and 64% of total building energy usage was consumed by residential buildings. Thus, about 10% of total domestic energy consumption is due to the heating of residential buildings. Building energy can be calculated by the configuration of the building envelope and the rate of infiltration (the volume of the infiltration of outdoor air and the leakage of indoor air), and by doing so, the annual energy usage for heating and cooling. Therefore, air-tightness is an important factor in building energy conservation. This investigate air infiltration and various factors that decrease it in timber frame buildings and suggest ways to improve air-tightness for several structural types. Timber frame buildings can be classified into light frame, post and beam, and log house. Post and beam includes Han-ok (a Korean traditional building). Six light frame buildings, three post and beam buildings, one Korean traditional Han-ok and a log house were selected as specimens. Blower door tests were performed following ASTM E779-03. The light frame buildings showed the highest air-tightness, followed by post and beam structures, and last, log houses.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.25 no.8
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• pp.1103-1112
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• 2001

The effect of pressure gradients on the hairpin structures in three different turbulent boundary layers (ZPG : Re(sub)$\theta$=910, FPG : Re(sub)$\theta$=575, APG : Re(sub)$\theta$=1290) has been examined with instantaneous velocity fields obtained in streamwise-wall-normal planes using PIV (particle image velocimetry) method. In the outer layer hairpin vortices occur in streamwise-aligned packets that propagate with small velocity dispersion. The signature pattern of the hairpin consists of a spanwise vortex core located above a region of strong second quadrant fluctuation (u<0 and v>0 : Q2 event) is clearly observed. The formation of packets explains the occurrence of multiple VITA events in turbulent burst. Noticeable differences are found in the average inclination angles of hairpin vortex packets which are 45$^{\circ}$, 35.7$^{\circ}$, and 51.9$^{\circ}$in the case of ZPG, FPG and APG, respectively. It is found that the large, time-varying, irregularly shaped zones with nearly constant streamwise momentum exist throughout the boundary layer. Within the interior of the envelope the spatial coherence between the velocity fields induced by the individual vortices leads to strongly retarded streamwise momentum, explaining the zones of uniform momentum. The formation of the uniform momentum zone is remarkably different with respect to the pressure gradients especially in the logarithmic layer.

• The Journal of the Korean Society for Microbiology
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• v.10 no.1
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• pp.39-58
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• 1975

These studies were carried out to detect the presence of mycotoxin producing fungi in various kind of grains and foodstuffs in Korea. The experiments were divided into three parts: bacteriologic, toxicologic and electron microscopic studies. The results were summarized as follows: 1. From the 133 various samples, 426 colonies of fungi were isolated. In 405 of 426 colonies, it was possible to identify 17 genera. Among the identified strains, the predominant genera were Penicillium, Aspergillus and Alternaria. 2. In cytotoxicity test, 20 strains showed mild to severe toxic effects in mice and 24 strains showed toxic effects on HeLa cells among the 107 strains of experiments. 3. In electron microscopic studies of liver cells from animal which had been treated with toxin like substances, the liver cells showed the cytoplasmic changes: dilatation of endoplasmic reticulum, swelling of mitochondria, disappearance of mitochondrial cristae, increased number of lipid and glycogen particles. Nucleus and nuclear envelope alterations were also noted. 4. In fine structure of HeLa cells treated with culture filtrates of mycotoxin producing fungi and experimental strains had been noted a certain specific changes induced by culture filtrates. These alterations showed the disappearance of golgi complex, endoplasmic reticulum vacuolization and mitochondrial changes. 5. As a mass screening, the cytotoxicity tests of HeLa cells and histopathologic study of mice liver cells treated with toxin-like substances, employed are feasible to detect mycotoxin producing fungi.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.26 no.1
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• pp.14-19
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• 1990

This paper describes on the characteristics of the acoustic echoes from the scattering layers by the aggregation of marine organisms which was measured by using a 50kHz echo sounder on board of the training ship SAEBADA belong to National Fisheries University of Pusan during the summer, 1989 in the East China Sea. A data acquisition system was used to record digitally the envelope of the echoes and the frequency distribution of echo amplitudes on the whole water column was examined as a function of time during the sunrise and sunset periods. Acoustic data showed that the abundance distribution of marine organisms according to depth in the servery area changed with time and that the organisms were most active during the twilight of morning, and the echo strength on the water column or scattering layer was also strongest during this time. Additional results of this survey suggest that other interest, such as the relationship between environmental conditions and biomass depth distribution, could be also investigated in hydroacoustic method.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.26 no.1
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• pp.51-56
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• 1990

The authors carried out an experiment to investigate the echo fluctuations from ocean bottom due to ship's motion. The bottom echoes was continuously measured, by using a 50 kHz Echo sounder on board of the ship being at anchor under the sea condition of 15 knots in wind velocity and approximately 2 meters in wave height, to extract the information about the pulse stretching and the ship's motion from the first return and the second return. A data acquisition system was used to record digitally the envelope of the echoes, and the analysis was applied to the echo data collected from the continental shelf in the South China Sea. The results obtained can be summarized as follows: 1. The equivalent pulse width of the second return echoes from ocean bottom was 2.4 times longer than that of the first return echoes. 2. The echo peak values of the first return fluctuated markedly than that of the second return and was shown to be extremely sensitive to small change in ship's motion. 3. Energy target strength and peak target strength of the sandy-mud bottom were -13.4 dB and -14.6 dB, respectively.

• Journal of fish pathology
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• v.13 no.1
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• pp.7-13
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• 2000

Beginning in the summer of 1993, a serious mortality among cultured penaeid shrimp occurred in the western sea of Korea. The typical sign of this disease was white spots inside the surface of the carapace. Cytopathic effect (CPE) were not observed by virus in CHSE-214, RTG-2, but not by pH 11. A nonoccluded rod-shaped form virus was observed by electron microscopy in the lymphoid organ. The virion was bacilliform virus and sourrounded by a virion envelope. Its virion protein was found to be similar to hypodermal and hematopoietic necrosis virus (HHNBV) by analysis of virion proteins in SDS-PAGE. The genome of virus is double stranded DNA molecule whose full length was about 114kb. It was similar to penaeus acute viremia (PAV) of Japan.

• Journal of environmental and Sanitary engineering
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• v.23 no.3
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• pp.9-22
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• 2008

This study was conducted to develop a system that processes harmful gases and dust, which being generated in the production of micro-inorganic fabric. This can be obtained by melt spinning raw materials such as agalmatolite, fluorspar, limestone, silica under high temperature at $1500-1600^{\circ}C$ in a glass recuperator using a dry method by Cyclone Reactor or Envelope Type (ET) type Bag Filter. If the number of the members of Korea Glass Industry Association reaches up to 45, the damage of the harmful gas being generated in recuperator should not be small. In addition, research of existing facilities showed the most of harmful gas treatment facilities which adopt wet treatment or semi-dry treatment process. This was caused the problems for wastewater and the second pollutive materials. Moreover, in the dust collecting facility behind recuperator, it is also problematic that electric dust collector requires enormous initial investment. We have researched various methods to show both economic and efficient new processes for the preventive facilities of recuperator. As the result of the experiments, the removal efficiencies of HF and SOx were 99% and 87%, respectively. Although it was insignificant reaction, a pretty much interesting result that NOx showed an absorption reaction with $Ca(OH)_2$(removal efficiency was more than 25%) was obtained.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.11
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• pp.1383-1389
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• 2011

Gerotor-type volumetric displacement pumps are suitable for oil or water hydraulics. For this reason, many researchers have studied this topic. Gerotor pumps have been widely used in various fields. In this study, we designed a rotor profile based on an envelope of a family of curves. An analytic method for determining the volumetric displacement of the gerotor pump is verified by comparing a result obtained using CAD technology and an experimental result. Throughout the experiment, the flow rate performance was verified. In addition, we describe the design and volumetric displacement characteristics of the gerotor pump.

• Ocean Science Journal
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• v.40 no.3
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• pp.177-182
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• 2005

The process of embryogenesis and larval development of the asteroid sea star Asterias amurensis $(U{\ddot{u}}tken)$ was observed, with special attention paid to morphological change and larval duration. In reproductive season, mature sea stars were collected under floating net cages, located in Tongyeong, southern Korea. The mature eggs are $138\;{\mu}m$ in average diameter, semi-translucent and orange in color, sperms in good condition appear light cream to white-gray in color. Embryos develop through the holoblastic equal cleavage stage and a wrinkled blastula stage that lasts about 9 hours after fertilization. Gastrulae bearing an expanded archenteron hatch from the fertilization envelope 22 hours after fertilization. At the end of gastrulation, rudiments of the left and right coelom are formed. By day 2, larvae possess complete alimentary canal and begin to feed. At this stage, the larva is called early bipinnaria. In 6-day-old larvae, the pre- and post- oral ciliated bands form complete circuits and the bipinnarial processes start to develop. By day 12, the lateral and anterior projection of the larval wall processes along the ciliated bands begins to thicken and curl, and the ciliated bands become more prominent. By day 32, early brachiolaria are presented with three pairs of brachiolar arms. Advanced brachiolaria with a well-developed brachiolar complex (three pairs of brachia and central adhesive disc) occur 6 weeks after fertilization. In the field, spawning of the sea star was observed in April to May, settlement form larvae and just settlements seem to occur from June to July, and early juveniles occur from August to September. Although we had not described the end of brachiolaria stage, it can be tentatively estimated that the duration of the pelagic stage of A. amurensis is 40 to 50 days.

• Journal of the korean veterinary medical association
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• v.23 no.9
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• pp.603-610
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• 1987

The pathological and microbiological studies were carried out to investigate an acute, febrile, highly fetal, infectious disease of rabbits that had occurred in the Winter and in the Spring and that had begun to be reported in Korea from November, 1985. The clinical signs of this disease were characterized by high fever, lethargy, piercing shriek, convulsion, and sudden death with epistaxis, but often they were not observed. The predominant pathogical findings were severe congestion and hamorrhage in trachea, dark brown discoloration of liver by diffuse necrosis or acute viral hepatitis, and hamorrhagic damages of lung, heart, spleen, kidney, etc. The etiological agent was a small round virus, in 25-35nm in diameter and without envelope, thus looking like a picorna virus. This disease resembled what was called the 'Viral Hamorrhagic Pneumonia in Rabbits'(tentative name) that had been reported for the first time in China in 1984. It will be desirable that the disease should be renamed as the 'Viral Hemorrhagic Fever in Rabbits', the 'Acute Viral Hepatitis in Rabbits', etc. because of its charateristics and the basis of pathological findings. An inactivated vaccine is now in the process of preparation for the prophylaxis of this viral disease.