• The Korean Journal of Mycology
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• v.23 no.3 s.74
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• pp.266-274
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• 1995

Fresh fungi were collected during field trips to mountain areas throughout the country from May to October of 1994. Through the observation and identification of specimens belonging to the Aphyllophorales, two genera, Botryohypochnus and Vesiculomyces, and seven species, Botryohypochnus isabellinus, Phanerochaete laevis, Vesiculomyces citrinus, Gloeoporus pannocinctus, Junghuhnia luteoalba, Inonotus andersonii, and Inonotus hispidus, were confirmed new to Korea and are registered here with descriptions.

• Journal of the Korean Chemical Society
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• v.48 no.4
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• pp.399-413
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• 2004

In this study, a survey was conducted of students of elementary through college on their conceptions of phenomenon related with dissolution, saturation, and extraction. The teaching strategies of elementary and secondary teachers related to dissolution phenomena were also investigated. Most of elementary and secondary school students thought of dissolution as a phenomenon in which particles broke into the spaces between other particles. This explanation called 'space conception' can be sought in elementary school science textbooks. Some of high school students also had this type of thought. A concept of dissolution phenomenon as 'hydration through attraction of solvent and solute' was held by most of students of 11th, 12th grade, and college. This explanation called 'attraction concept' can be sought in high school chemistry textbooks for 11th and 12th grade. But many students of elementary through college used analogies and models related to 'space conception' when they tried to explain the dissolution phenomena. This indicates that the 'attraction concept' was not firmly established in the students' cognition. 90% of elementary school teachers thought and taught dissolution as a phenomenon in which two different size particles were mixing together like as mixing beans and millets. The model does not represent the attractions among solvent-solvent particles, solvent-solute particles, and solute-solute particles. This model only represents the space size effect (smaller size particles fitting into the spaces of larger size particles). Half of the secondary school teachers also had 'space conception' and only 20% of the teachers had 'attraction concept' Many teachers who had 'attraction concept' used to represent explanation related to 'space conception' for teaching dissolution.

• Korean Journal of Environmental Biology
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• v.20 no.2
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• pp.180-188
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• 2002

Sand dollar, Astriclypeus manni (Echinodermata: Echinoidea) is widely distributed on subtidal sand flats all along the coast of Cheju Island. Limited information has been reported on their ecology despite their abundance. This study reports gut contents, density and locomotion of the sand dollars distributed on a subtidal sand flat on the north-east coast of Cheju Island. Microscopic examination of the gut contents indicated that A. manni feeds on inorganic and organic detritus as well as live organisms contained in the sediments. Inorganic particles included sand grains, sponge spicules and shells of benthic animals such as foraminifera, crustacean and molluscs. Mean diameter of sediment particles retained in the gut was $77.6\pm{22.2}\mu{m}$. Live organisms retained in the gut included foraminifera, harpacticoid copepods, nematodes, diatoms and unidentified egg. Spatial distribution pattern of the sand dollar was found to be random with a mean density of 0.4 individual $m^{-2}(\chi^2=85.16,\;p>0.05)$. Locomotion speed of the sand dollar measured in situ was 2.0 to 65.0 cm $hr^{-1}$. Locomotion speed and moving distance was somewhat higher in summer when food availability also higher.

• Journal of Mushroom
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• v.10 no.1
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• pp.15-20
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• 2012

Ventilation effects of bottles($1,100m{\ell}$) for culturing Flammulina velutipes on its mycelial growth and mushroom production were investigated. The degree of ventilation were controlled with hole positions, upper and under, and hole sizes in the bottle lids. The ventilation effects were measured with the contents of carbon dioxide, free sugars, chitin, moisture in the bottles and with the amount of produced mushrooms from the bottles. Carbon dioxide concentrations within the culturing bottles at exponential mycelial growth period vertex were relatively high in the bottles with lids without both a sponge and an aeration hole, and in those with a smaller hole. Free sugar contents in the mycelia were the highest in those with a 47mm hole on both sides, and in those with 26~33mm holes only underside. Chitin content was the highest in those with a 26mm hole only underside. On the other hand, the lids with 42mm~47mm holes on the both sides greatly lost water and decreased the mushroom production. In conclusion, the most efficient ventilation hole sizes on the lids for bottle($1,100m{\ell}$) cultivation of Flammulina velutipes using $1,100m{\ell}$ polypropylene bottle were 19mm on both sides of the lid and 26mm on only underside. They produced more mushrooms than the control by 6~9 %.

• Journal of the Korean earth science society
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• v.30 no.4
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• pp.454-463
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• 2009

In this study, from January 2006 to February 2009, we observed 107 ice spikes formed in a natural state, and analyzed their environment. We developed an experimental device to reproduce ice spikes in laboratory and successfully made 531 ice spikes. We analyzed the process of the formation and the principle of how those ice spikes grow through videotaped data of the formation in the experiment. In the natural world, when the surface of water and the lower part of a vessel begin to freeze, a vent (breathing hole) develops at the surface where an ice is not frozen; this vent serves as the seed of an ice spike. It is assumed that the volume expansion of ice in the vessel which occurs when water freezes makes the supercooled water go upward through the vent and becomes an ice bar called an ice spike. In the laboratory, however, when distilled water is poured into an ice tray cube and kept in the experimental device for about one and a half hours at a temperature of -12- $-13^{\circ}C$, a thin layer of ice then begins to develop on the surface of the water, the vent is formed, and ice spikes form for about 10-30 minutes. These spikes stop growing when the end becomes clogged. Ice spikes can be described as falling into seven categories of shape, with the apex type topping the list followed by the slant type in the natural state and the vertical type predominating in the laboratory.

• Journal of Broadcast Engineering
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• v.26 no.6
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• pp.714-724
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• 2021

The point cloud content is immersive content recorded by acquiring points and colors corresponding to the real environment and objects having three-dimensional location information. When a point cloud content consisting of three-dimensional points having position and color information is enlarged and rendered, the gap between the points widens and an empty hole occurs. In this paper, we propose a method for improving the quality of point cloud contents through inverse transformation-based interpolation using depth information for holes by finding holes that occur due to the gap between points when expanding the point cloud. The points on the back are rendered between the holes created by the gap between the points, acting as a hindrance to applying the interpolation method. To solve this, remove the points corresponding to the back side of the point cloud. Next, a depth map at the point in time when an empty hole is generated is extracted. Finally, inverse transform is performed to extract pixels from the original data. As a result of rendering content by the proposed method, the rendering quality improved by 1.2 dB in terms of average PSNR compared to the conventional method of increasing the size to fill the blank area.

• Korean Journal of Environmental Biology
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• v.17 no.4
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• pp.427-438
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• 1999

Differential growth of Ulva pertusa Kjellman was observed in response to different photon irradiances and seawater. Growth rate of U. pertusa cultivated in the seawater collected from the East Sea was significantly higher than that in the seawater collected from the Yellow Sea. Optimal growth was found at $100{\mu} molm^{-2} s^{-1}$ in both cases. Chlorophyll contents of U. pertusa grown in the east sea water were higher than that cultivated in the west sea water at irradiances lower than $60{\mu} molm^{-2} s^{-1}$. At irradiances higher than $100{\mu} molm^{-2} s^{-1}$, there was no difference in chlorophyll content in between the two different sea waters with tendency that pigmentation decreased with increasing photon irradiances. Nitrate concentration in the west sea water was 2-fold higher than that in the east sea water, while phosphorus concentrations (0.03 ppm) were similar. Concentrations of $Cu^{2+}$ and $Pb^{2+}$ were 0.004 and 0.003 ppm respectively which are far below environmental standard concentrations (0.02 ppm for $Cu^{2+}$ and 0.1 ppm for $Pb^{2+}$). Taking those data into account, we have done laboratory investigations into the effects of inorganic nutrients and heavy metals on U. pertusa. As nitrate concentration increased from 0.5 to 5 ppm, growth rate of U. pertusa increased, but different concentrations of phosphorus did not cause any differential effect. On the other hand, chlorophyll contents increased with increasing phosphorus concentrations. Copper of U. pertusa be toxic decreased the growth and pigmentation as the concentration increased, whereas lead showed no such effect. Concentrations of $Cu^{2+}$ employed in the present study were much higher than those in ambient seawater. Intermittent soaring of $Cu^{2+}$ level as observed in natural seawater could, however, seriously damage the growth behaviour of U. pertusa.

• The Hankook-Saengyark Bo
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• no.263
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• pp.1-1
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• 2005

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.8 no.2
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• pp.7-16
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• 1999

• 월간산업보건
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• s.9
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• pp.22-36
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• 1988