• Proceedings of KOSOMES biannual meeting
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• 2004.05b
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• pp.49-52
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• 2004

RADARSAT is one of many possible data sources that can play an important role in marine surveillance including ship detection because radar sensors have the two primary advantages: all-weather and day or night imaging. However, atmospheric effects on SAR imaging can not be bypassed and any remote sensing image has various geometric distortions. In this study, radiometric and geometric calibrations for RADARSAT/SAR data are tried using SGX products georeferenced as level 1. For radiometric calibration, information on the magnitude of the radar backscatter coefficient of the imaged terrain is extracted from the processed image data. Conversion method of the pixel DNs to beta nought and sigma nought is also investigated Finally, automatic geometric calibration based on the header file is compared to a marine chart.

• Korean Journal of Ecology and Environment
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• v.38 no.3 s.113
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• pp.352-360
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• 2005

Acheilognathus signifer is distributed widely in high density in the Naechon-stream. The order of this-stream was 2 ${\sim}$ 4 and the water width is wide but the depth is relatively shallow and the sinuosity is 1.83, which indicates a meandering stream. The water width/stream width ratio is 1.59, which suggests moderate entrenchment. Naechon-stream was classed as B type by Rosgen (1995). The natural habitat of A. signifer is a slow flow velocity pool, like a backwater pool, which is made up of piled up boulders that restricts the flow of water. The stream bed is made up of boulders and sands that enable the spawning host to inhabit. A. signifer selects a microhabitat where the boulders furnish hiding places. The Habitat of A. signifer is strongly affected by the existence or not there of U. douglasiae sinuolatus. After hatching from the mussel, A. signifer inhabits the surface of the water. It then moves to the low layer once it acquires swimming ability. While A. signifer inhabits the river in summer, A. signifer moves to the deeper layers in winter, where there are the refuge like rocks and boulders. In spring A. signifer moves from the deep water to the river line where the mussels reside.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.5
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• pp.707-712
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• 1998

Seasonal variation in the proximate composition, cholesterol (CHOL) and $\alpha$-tocopherol ($\alpha$-Toc) content of 12 spices of fish muscle, which caught off Tongyeong coast of the Southern Sea (Nam-Hae) from Mar. 1995 to Feb. 1996, was studied. Lipid and moisture content showed remarkable seasonal variation and there were a negative correlation between the both (r= -0,85, p<0.001), while protein and ash content unchanged almost through the sampling period. The lipid content of anchovy, hickoryshad, black sea bream, finespotted flounder sea eel, bastard, and file fish was high in Dec. Oct. Nov. Jan. Jan. Nov, respectively, and low in the season corresponding to their spawning period. However, in case of striped mullet, yellow tail, mackerel, rock fish and red sea bream, there was no correlation between their lipid content and spawning period, and thus these fishes fore considered to be affected more by water temperature and the content of their diet. CHOL content increased In :he season containing a high level of lipid, whereas $\alpha$-Toc content unchanged almost through the sampling period.

• Journal of Aquaculture
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• v.18 no.2
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• pp.107-114
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• 2005

Clownfish are important and very popular fish in the ornamental aquarium industry. Demand for the fish is increasing dramatically. The present study was conducted to verify methods of broodstock management, patterns of spawning, rates of egg hatching and estimates of larval growth fur the saddleback clownfish, Amphiprion polymnus. Spawning occurred 8 times between August 2002 to June 2004 with 2 females and 1 male participating. Fertilized eggs were separated by an adhesive matrix and were oval in shape. The eggs were $2.46{\pm}0.13mm$ in size as measured along the longest axis. The percentage of fertilized eggs was 96.7%. Hatching was observed seven days post-spawning and hatching rate was 85.5%. The sizes of the newly-hatched larvae were $4.58{\pm}0.21mm$ TL (total length). Larvae had an open mouth and anus, and an oval yolk sac. At the 1 st day after hatching, the sizes of the larvae were $4.90{\pm}0.35mm$ TL. The larvae began to eat rotifers after complete yolk absorption. On the 5th day post-hatch, larvae were $5.88{\pm}0.31mm$ TL with complete fins and the survival rate was 48.6%. At 8 days after hatching, a band began to appear on head and back of the larvae indicating the beginning of metamorphosis. Metamorphosis was completed at an average TL of $15.00{\pm}2.12mm$ on the 23rd day after hatching. By the 45th day after hatching, juveniles averaged $22.76{\pm}3.22mm$ TL and survival rate was 28.4%.

• Korean Journal of Poultry Science
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• v.16 no.2
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• pp.73-81
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• 1989

This study was conducted to estimate heritabilities, genetic and phenotypic correlations on economic traits in layers. The data analysis were the records of 351 pullets in S. C. W. Leghorn and 326 pullets in R. I. Red from March 1, 1980 to July 31.1981. The results obtained are summarized as follows：1 The average body weights at the first egg, 300 and 500 days of age were 1, 409, 1, 602 and 1, 709g S. C. W. Leghorn, and 1, 965, 2, 305, and 2, 479g in the R. I. Red, respectively. The age at first egg of the S. C. W, Leghorn and R. I. Red were 156 days and 163 days, respectively. The number of egg produced by the S. C. W. Leghorn and R. I. Red to 300 days and 500 days of age were 101.18, 214.39, and 101.05, 214.93, respectively. The egg weight at first egg, 300 and 500 days of age were 41.93, 57.65 and 60.33g in the S. C. W. Leghorn and 41.52, 57.62 and 60.57g in the R. I. Red, respectively. 2. The heritability estimates based on the variance of sire and dam components were 0.402-0.612 and 0.275-0.458 in the S. C. W. Leghorn, 0.309-0.523 and 0.134-0.380 in R. I. Red for body weight； 0.167 and 0.139 in the 5. C. W. Leghorn, 0.169 and 0.095 in the R.1. Red for age at first egg：0.214-0.139 and 0.336-0.341 in S. C. W Leghorn, 0.137-0.259 and 0.024-0.102 in the R. I. Red for number of egg production； 0.537-0.769 and 0.374-0.686 in the S. C. W. Leghorn, 0.519-0.631 and 0.116-0.365 in the R. I. Red for egg weight, respectively. 3. The genetic correlation coefficients of economic traits were as follows： In the S. C. W. Leghorn and R. I. Red , the coefficients between body weights and age at the first egg, 0.328-0.426 and 0.186-0.244：between body weights and number of egg production, -0.666--0.498 and -0.452--0.073：between body weight and egg weight, 0.384-0.774 and 0.126-0.612； between age at first egg and number of egg production, -0.639--0.452 and -0.754--0.320； between age at first egg and egg weight, 0.475-0.705 and 0.021-0.605； between number of egg production and egg weight, -0.623--0.355 and -0.861--0.327, respectively.

• Journal of Animal Science and Technology
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• v.49 no.4
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• pp.481-490
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• 2007

An experiment was conducted to investigate the effects of dietary supplementation of MOS, lectin and organic acid mixture(Organic acid F, Organic acid G) on the egg production, egg quality, profile of leukocytes and erythrocytes, small intestinal microflora and immune response in laying hens. A total of 900 Hy-line BrownⓇ laying hens of 48 wks old were assigned to one of the following 6 dietary treatments:control(C), C+AvillamycinⓇ 6ppm, C+MOS 250ppm, C+lectin 12.5ppm, C+Organic acid F(formic acid 35.4%, formate 34.6%, potassium 30.0%) 0.3% and C+0rgarnic acid G(fumaric acid 23%, calcium formate 14%, potassium sorbate 5%, calcium propionate 7%) 0.06%. Each treatment was replicated five times with thirty birds per replicate, housed in 2 bird cages. Feeding trial lasted for 6 wks under 16 hours lighting regimen. All supplemental groups were higher than the control in 6 wks hen-day and hen-housed egg production showing the highest with MOS treatment(P<0.05). Soft & broken egg productions were lower in supplemental groups than in the control except lectin treatment(P<0.05). Eggyolk color of supplemental groups was higher than that of the control except Organic acid G treatment(P<0.05). The values of RBC, HB, MCHC were highest in lectin treatment and lowest in MOS treatment(P<0.05). The numbers of intestinal microflora were not significantly different among the treatments. Serum IgG levels of all supplemental groups were higher than those of the control(P<0.05). In conclusion, for supplementation of antibiotics, immune modulators and organic acid mixture improved production parameters in general. Among the supplements, MOS showed the best performance in egg production and eggyolk color.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.1
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• pp.49-54
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• 2017

We collected and reared Theragra chalcogramma walleye pollock brood-stock for use in natural spawning tests and undertook to obtain domestic pollock via fertilized egg capture, development of fertilized eggs, and absorption of yolk sac after hatching. Whole pollock were caught with trammel and set nets and immediately placed in a deep-sea water tank. Adults were the most common pollock age group (43.0%; n = 86) among the 254 pollock captured in March 2014 with 57.9% (n = 147) being captured off Southern Gosung, Korea. The main spawning period of pollock is February (spawning phase of 91% of pollock). From the deep-sea tank, we collected 1640 mL of naturally fertilized eggs (~820,000 eggs) from 12 spawning events occurring between February 4 and 22 2015. The floating/ live eggs were maintained in deep-sea water tanks at $5.5{\pm}0.2^{\circ}C$. Egg size was $1.5{\pm}0.03mm$. Six hours after fertilization the eggs were at the 2 cell stage, and the eggs hatched approximately 340 hours after collection. At hatching, larval length and yolk sac area were $5.2{\pm}0.25mm$ and $9.5{\pm}1.00mm^2$ (100%), respectively. Four days after hatching, the yolk sac area was $2.2{\pm}0.53mm^2$ ($23.1{\pm}5.55%$). This is the first report of collection of naturally fertilized eggs from pollock and their subsequent hatching while held in an indoor deep-sea water tank. The results suggest that such collection could assist in the recovery of pollock resources and the possibility of domestic rearing of cultivated larvae.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.1
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• pp.52-57
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• 2016

We introduce a hybrid scheduling in a multi-path poor scattering full-duplex (FD) system, which consists of one multi-antenna FD base station and a large number of single-antenna half-duplex mobile stations. Our hybrid scheduling utilizes partial channel state information at the transmitter. In particular, unlike the conventional scheduling method using opportunistic transmission for both uplink and downlink, the proposed scheme combines a random transmit beamforming for downlink and a zero forcing beamforming for uplink. As our main result, via computer simulations, it is shown that the proposed scheme has a superior sum-rate performance than that of the conventional scheduling method beyond a certain signal-to-noise ratio regime.

• The Korean Journal of Malacology
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• v.24 no.3
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• pp.261-267
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• 2008

The tendency of metabolism in oyster, Crassostrea gigas, was investigated in relation to the water temperature and salinity. Oxygen consumption and ammonia excretion were measured and O:N ratio were calculated according to the water temperature from February 2007 to September 2008 and body size. The relationship between oxygen consumption and body weight has been examined in C. gigas. The weight-specific oxygen consumption rate (mg $O_2$/g/h) varied inversely with size. Oxygen consumption and ammonia excretion increased with an increase in water temperature. O:N ratio measured in this study ranged from 8 to 40 under ordinary sea water and the ratio was 8 at $25^{\circ}C$ and 16 at $10^{\circ}C$. This indicates that oyster mainly use the protein as the primary catabolic substrate during gametogenesis. Lower O:N ratio in winter suggests that oysters have to meet their energy demand by metabolizing protein to survive in stressful conditions such as low temperature and lack of sufficient food supply. This studies will provide the basic data for oyster culture farm in assessing the carrying capacity and sustainable management.

• Korean Journal of Ichthyology
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• v.29 no.1
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• pp.69-74
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• 2017

Age and growth of Brown croaker Miichthys miiuy were estimated using right sagittal otoliths of 327 fish specimens from August 2015 to July 2016 in Korea. Annual rings in otoliths were formed from March to June once a year. The oldest specimens were 11 yr in female and 9 yr in male. Brown croaker began spawning in September and showed a peak in October. Total length and body weight relationships showed no significant difference between females and males (P>0.05), and can be expressed as $BW=1.15{\times}10^{-5}{\times}TL^{2928}$ ($R^2=0.98$). Estimated von Bertalanffy growth curve was $L_t=182.4(1-e^{-0.067(t+1.754)})$ ($R^2=0.96$).