• Korean Journal of Ichthyology
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• v.24 no.1
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• pp.56-61
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• 2012

The distribution status and population size of the endangered species, $Cobitis$ $choii$, were investigated in the Guem River, Korea. From 1984~2004, this species occurred at 20 survey stations; however, their numbers have but rapidly decreased in recent years (2006~2011), during which time they were only observed at six stations. The area of their habitat is narrow and occurs in primarily downstream, sandy zones. Using the mark-recapture method, populations were estimated at 9,106 and 34,717 individuals for the main habitats of Baekgok and Ji Stream, respectively.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.13 no.4
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• pp.342-347
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• 2008

Mortality and growth rate of the soft coral, Dendronephthya gigantea, from Jejudo Island on the southern coast of Korea were investigated from February 2003 to October 2004 using SCUBA diving. 48 individuals with variable sizes of D. gigantea of the depth of 15m were tagged with flagging tapes and plastic films, and then monitored with two month intervals. The average mortality of two-month term for the study period was 50.4%, with the peak of 84.6% during the summer storms in August - October 2003. About the size class mortality, individuals of size class I(${\leq}$10 cm) showed the highest mortality, followed by size class III(>20 cm) and size class II(10 cm-20 cm). Growth rate did not show a seasonal pattern. For growth in length, individuals of D. gigantea grew about 3cm in average for two-month period, with a maximum growth of 6.4 cm which occurred in August - October 2003. For growth in diameter, individuals grew about 0.3 cm for 2 month term, with a maximum of 1.4cm in April - June 2004. Individuals of size class I usually grew faster than those of larger size classes. D. gigantea population in Jejudo Island was strongly affected by summer storms, which was due to annual event of summer typhoon. Never the less, it appears that the local population can be maintained by fast growth of the juvenile stage and active recruitment to compensate the high mortality caused by the summer disturbance.

• Journal of Korea Game Society
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• v.8 no.2
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• pp.57-68
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• 2008

Texture Mapping is a technique for adding realism to an image in 3D graphics Chip. Bilinear filtering mode of this technique needs accesses of 4 texels to process one pixel. In this paper we analyzed the access pattern of texture, and proposed the high performance texture cache which can access 4 texels simultaneously. We evaluated using simulation results of 3D game(Quake 3, Unreal Tournament 2004). Simulation results show that proposed texture cache has high performance on the case where physical size is less then or equal 8KBytes.

• ALGAE
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• v.19 no.2
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• pp.91-105
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• 2004

Ten taxa of the genus Spirogyra (Zygnemataceae, Chlorophyta) in Korea were examined for morphology and taxonomic category with field as well as cultured materials: S. africana (Fritsch) Czurda, S. decimina (Muller) Kutzing, S. distenta Transeau, S. dubia Kutzing, S. ellipsospora Transeau, S. ellipsospora var. crassoidea Transeau, S. gracilis (Hassall) Kutzing, S. submajuscula Kutzing, S. peipingensis Jao and S. variformis Transeau. Features of vegetative cell and female gametangium, shape of septum, chloroplast number, sexuality, size and shape of zygospore, and ornamentation of spore wall were major characteristics used for determination of the species. All of them were described for the first time in Korea.

• Korean Journal of Materials Research
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• v.14 no.7
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• pp.505-510
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• 2004

The glass-ceramic based on LAS($Li_{2}O-Al_{2}O_3-SiO_{2}$) system was observed using SEM(Scanning Electric Microscopy) and AFM(Atomic Force Microscopy) and it was expected to get a correlation between the crystal size and the surface roughness through the result. At heat treatment conditions (the nucleation: $740\~800^{\circ}C$, the crystal growth: $900\~1150^{\circ}C$), the crystal size was increased from 72 to 450 nm so that the mean of surface roughness was also risen from 0.8 to 6.3 nm. Based on the results, the surface roughness of glass-ceramic is controlled by the factors, crystal size, crystallines, and the condition of heat treatment.

• Korean Journal of Materials Research
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• v.14 no.10
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• pp.725-730
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• 2004

Nickel ultrafine powder have been synthesized by chemical reduction of aqueous $NiSO_4$ with hydrazine at various reaction conditions. The effect of reaction conditions such as the amount of surfactant and reductor, and reaction temperature on the particle size and shape was investigated by the mean of XRD, SEM and SEM-PSA. Experiments showed that the ratio of $N_{2}H_4/Ni$ and the reaction temperature were affected on the particle size of the nickel powder. The average particle size of synthesized nickel powder increased with increasing reaction temperature regardless of the ratio of $N_{2}H_4/Ni$. Also the surfactant could influence the size and agglomeration of ultrafine powder with the reaction temperature.

• Journal of the Society of Naval Architects of Korea
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• v.41 no.1
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• pp.64-69
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• 2004

In recent years, Medium size high speed Ro-Pax vessel has appeared at European sea and especially Agean sea is a center of operating in this type of Ro-Pax. This vessel operates its high Froude number range and requires higher engine power due to considerably increased resistance in comparing to large Ro-Pax in high speed range. SHI has investigated this kind of high speed Ro-Pax in accordance with market requirements and developed more advanced vessel to meet the future market needs. Process of hull form development, model test results and design of general arrangement results are introduced in this paper.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.216-219
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• 2004

Due to the recent amazing achievements in nano technology. preparation of cement nano particles by mechanical method are examined to improve their properties. The experimental results show that the particle size after 3 hr milling were about 500nm. The SEM photographs of specimens also reveal that average sizes of cement particles are gradually decreased by milling time. And in the TG/DSC, influence of the alcohol is showed strongly. The value of TG of the crushed cement was larger than that of the non-crushed cement. That is also judged to be cause the alcohol.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2004.11a
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• pp.501-502
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• 2004

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2004.11a
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• pp.353-354
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• 2004