• Journal of the Korean Society of Environmental Restoration Technology
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• v.9 no.3
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• pp.51-58
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• 2006

The purpose of this research presents a method to position and makes the structure for eco-corridors reasonably with collectable analysing results of various effects shown in mammals' road-kill at 429 points. Target animals of this research are Leopard cat, Siberian weasel, Raccoon dog, Korean hare, Eurasian red squirrel, Siberian chipmunk and Water deer. The results derived from the empirical analysis on the contents above are followed. First, according to the results as for Leopard cat road kill analysis, which is designated as Endangered Species Class II, the eco-corridor might be located at near village having stead food in order to decrease the frequencies of road-kill, because its road kill points were mainly collected at 4 lane hilly road with mountain-road-farm area geological type of. Second, because Siberian weasel's road kill was detected at 2 lane hilly road with mountain-road-stream geological type, the eco-corridor might be located at near a mill to decrease road-kill frequencies. Third, the road-kill frequency of Eurasian red squirrel can be reduced when the eco-corridor is located at the area across coniferous tree near 4 lane west sea freeway with mountain-road-mountain. Fourth, the road-kill of Raccoon dog can be reduced when the eco-corridor is located at 4 lane mountain road or hilly road with the geological type having farm land-road-mountain(stream). Fifth, Korean hare's road-kill can be reduced when the eco-corridor is located at grass land across ridge line of mountain, because wild rabbit road kill was happened at 4 lane mountain road or 2 lane mountain road(mountain-road-mountain). Sixth, As for Siberian chipmunk, the eco-corridor might be located at the side slope of mountain road at 2 lane mountain road under the speed of 60km/h with mountain-road-mountain. Seventh, For Water deer, the eco-corridor might be located at 4 lane hilly road with mountain-road-farm land. As for Common otter, Amur hedgehog, Yellow-throated marten, Weasel, it is difficult to specify the proper site of eco-corridor due to the lack of data. Eco-corridors for carnivores might be well located at 4 lane hilly road or 2 lane hilly road with mountain-road-farm land, and the track for herbivores might be well located as a overhead bridge on mountain-road-mountain type across mountains. In order to position eco-corridors for wildlife properly, we have to research animal's behavior with ecological background, and to consider the local uniqueness and regularly collect the empirical road-kill data in long term 3 to 5 year, which can be the foundation for the more suitable place of wild life eco-corridors.

• Development and Reproduction
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• v.15 no.2
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• pp.121-131
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• 2011

The aim of this study was to investigate the egg development and the color change of Amphiprion melanopus, by the live food and thyroid hormone. After fertilizing, it took 168 h until hatching. The size of hatching larvae were $3.5{\pm}0.3$ mm, and some individuals had small yolk sac. As reaching the particular age, they underwent the color change (metamorphosis) - Days after hatching (DAH) 10: black, DAH 15~20: the 3 white stripes appear, DAH 30: the dorsal & the caudal white stripe begin to disappear. DAH 90: body color become red and orange, adult: cinnamon body color and a white stripe on head. - The group fed enriched Artemia with Tigriopus japonicus grew the faster than with only Artemia. The fin coloration of the one fed the only T. japonicus has a vivid red and orange color. $T_3$-treated group (4 ppm) grew the faster than the others (0, 2, 6 ppm). The size of the 6 ppm group was the smallest. The results suggest T. japonicus can be used as a supplement with rotifer and Artemia for the juvenile development and coloration. $T_3$ is considered to be involved in the metamorphosis and color formation of Amphipirion sp.

• Journal of the Korean Society of Marine Environment & Safety
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• v.21 no.2
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• pp.119-129
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• 2015

Benthic marine algal flora and community structure at Chuksan on the mid-east coast of Korea were investigated seasonally from July 2007 to May 2009. Ninety-eight seaweed species were identified, including 13 green, 23 brown and 62 red algal species. The number of species found ranged between 33 and 63 among seasons. Two green (Ulva australis and Codium arabicum), three brown (Dictyota dichotoma, Sargassum fusiforme and Sargassum yezoense), and eleven red algae (Corallina pilulifera, Lithophyllum okamurae, Pachymeniopsis elliptica, Grateloupia filicina, G. cornea, Hildenbrandia rubra, Chondrus ocellatus, Acrosorium polyneurum, Chondria crassicaulis, Polysiphonia morrowii and Symphyocladia latiuscula) were observed throughout the survey period. Average marine algal biomass was $629.68g\;dry\;wt\;m^{-2}$ and it ranged seasonally from 119.30 to $1,660.96g\;dry\;wt\;m^{-2}$. The vertical distribution of marine algae was characterized by Corallina pilulifera and Sargassum spp. in the intertidal zone; Sargassum spp. at 1 m depth; Sargassum spp. and melobesioidean algae at 5 m depth; and melobesioidean algae at 10 m depth.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.1 no.2
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• pp.63-71
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• 1968

Salted and dried yellow corvenia(Pseudosciaena manchurica), so called 'Gul-bi', is one of nation-widely consuming fish foo::ls. It is suitable for a long term preservation and its pro-duce is also a great deal on sea food processing in this country. The texture of 'Gul-bi', however, have often appeared to be a delicate factor for the quality of the product. The loss or dislocation of fat in the tissue of the fish resulted by salting and drying is believed to profoundly relate to the texture of product. In this paper, the tissue of yellow corvenia and movement of fat were microscopically observed before salting, immediately after salting, and after drying and the results observed in the tissues dry salted, brine salted, and brine salted with the addition of BHA were compared. The cross section of yellow corvenia muscle showed that a distinctive border by connective tissue between white and red muscle could not be seen in general, and red muscle was surrounded by hypodermic fatty tissues. In the tissue of fresh yellow corvenia, the fat was mainly distributed in hypodermic fat layer which located under the corium while rarely distributed in white muscle. It was found that some parts of the fat in the tissue were permeated into intermuscular tissue passing through the connective tissues during salting. The result Was the same in both dry-salting and brine-salting tissue. However, the fat translocated into intermuscular tissues disappeared during drying process in the salted without BHA tissues whereas in BHA added tissue. This result suggested that BHA may take a role of multiple effect in translocation of fat in tissues as well as in retarding oxidation. In an advanced stage of salted and dehydration, the muscle fibers were ajoined together and then limits between muscle fibers already became indistinguishable. And the migrated fat into intermuscular tissue aggregated around the connective tissue and are apt to gradually to flow out from the muscular system through these tissues.

• Journal of fish pathology
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• v.22 no.3
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• pp.283-291
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• 2009

This study was conducted to evaluate the effects of a commercial extruded pellet (EP) and raw fish moist pellet (MP) diet on disease prevalence and serum chemistry of olive flounder Paralichthys olivaceus grown in two commercial-scale aquaculture farms from July to December in 2008. The contents of serum GOT, GPT and glucose in fish fed EP diet (EP group) were higher than those of fish fed the MP diet (MP group). There were no distinct differences in survival rates and mean detection rates of fish pathogens among fish group fed the experimental diets. However, the mean detection rate of fish pathogens in MP group was higher than that of EP group from July to October which are high water temperature season. The dominant pathogens isolated in EP group were Dactylogyrus sp., E. tarda and red sea bream iridovirus (RSIV). On the other hand, Trichodina sp., Streptococcus spp., viral nervous necrosis virus (VNNV) were dominant in MP group.

• Korean Journal of Microbiology
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• v.45 no.4
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• pp.397-403
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• 2009

For the research of the natural antioxidant from marine sources, an antioxidant-producing marine actinomycetes was isolated from sea water in Jeju coastal area. The strain was identified based on 16S rDNA sequencing, the morphology by a method of scanning electron microscopy, physiological and biochemical characteristics and cellular fatty acid analysis. The isolated strain ACT-1 cell size was $0.5\sim1.0{\mu}m$ and gram positive, aerobic, nonmotile, substrate mycelium are red and gray aerial mycelium. 16S rRNA sequence analysis showed that were Gram-positive bacteria grouped on Streptomyces genus. Results of cellular fatty acid analysis showed that major cellular fatty acids were $C_{15:0}$ anteiso (39.33%), $C_{16:1}$ cis 9 (11.96%), $C_{16:0}$ (13.08%) and $C_{17:0}$ anteiso (10.99%). Finally, strain was identified Streptomyces sp. ACT-1. The antioxidant activity of methanol extract from Streptomyces sp. ACT-1 was evaluated by measuring DPPH, hydroxyl, and alkyl radical scavenging activity using an electron spin resonance (ESR) spectrometer. DPPH radical scavenging activity of SBME-1 (Streptomyces broth methanol extract) was 67% at $1,000{\mu}g$/ml. Hydroxyl radical scavenging activity of SBME-1 was 84% at $500{\mu}g$/ml. Alkyl radical scavenging activity of SBME-1 was 71% at $1,000{\mu}g$/ml.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.6
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• pp.568-577
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• 2002

The spreading Cocuoainim polykikoides bloom in the southern coastal waters of Korea was simulated using numerical model including the physical processes of water flow and the chemical processes of increasing cell of C. polykikoides by uptake of dissolved nutrients. The circulation of sea water was simulated by two dimensional tide model reflecting the main four tidal components of $M_2,\;S_2,\;K_1,\;O_1$, and permanent current was driven by inflow/outflow across open boundaries. According to the result of model which tidal and permanent current were reflected simultaneously, eastward flows entering the southern waters from the western waters of Korea are dominant but westward flows are weak relatively. These result suggest that it is difficult for initial C. polykikoides bloom generated in the coastal waters of Goheung to move to the western coast of Korea through Jeju Strait. For spreading model of C. poiyhikoides, the range of generating distribution and the generating time of C. polykikoides bloom in coastal area are similar to those of observation data in the field. Wind is the most important factor in moving and distribution of red tide. Permanent current flowing eastward is also considered to be important factor and tidal current was a little influenced.

• Korean Journal of Poultry Science
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• v.47 no.4
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• pp.237-245
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• 2020

This study investigated the effects of breed, laying age, and egg storage period on hatching performance. Eggs were collected from early laying period (27 to 29 weeks old) and late laying period (50 to 52 weeks old) in Hwanggalsaek Jaeraejong, Korean Rhode Island Red, and Korean White Leghorn chicken breeds. Eggs laid for each period were stored for 3, 7 and 14 days and then hatched. Fertility, hatchability, and embryonic mortality were observed to determine the hatching performance. The results showed that hatching performance was affected by breed, laying age, and egg storage period with independently or interactively. The Korean Rhode Island Red breed had the lowest hatching performance. Hatchability and early embryonic mortality rate increased in early laying period eggs compared to the late laying period, but the late embryonic mortality rate increased in late laying period eggs. Additionally, hatching performance decreased as the egg storage period increased. Using breed-specific hatching management techniques, avoiding late laying period eggs, and shortening the egg storage period to seven days after laying may improve the hatching performance.

• Journal of the Korean earth science society
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• v.45 no.3
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• pp.173-191
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• 2024

Typhoons are significant meteorological phenomena that cause interactions among the ocean, atmosphere, and land within Earth's system. In particular, wind speed, a key characteristic of typhoons, is influenced by various factors such as central pressure, trajectory, and sea surface temperature. Therefore, a comprehensive understanding based on actual observational data is essential. In the 2015 revised secondary school textbooks, typhoon wind speed is presented through text and illustrations; hence, exploratory activities that promote a deeper understanding of wind speed are necessary. In this study, we developed a data visualization program with a graphical user interface (GUI) to facilitate the understanding of typhoon wind speeds with simple operations during the teaching-learning process. The program utilizes red-green-blue (RGB) image data of Typhoons Mawar, Guchol, and Bolaven -which occurred in 2023- from the Korean geostationary satellite GEO-KOMPSAT-2A (GK-2A) as the input data. The program is designed to calculate typhoon wind speeds by inputting cloud movement coordinates around the typhoon and visualizes the wind speed distribution by inputting parameters such as central pressure, storm radius, and maximum wind speed. The GUI-based program developed in this study can be applied to typhoons observed by GK-2A without errors and enables scientific exploration based on actual observations beyond the limitations of textbooks. This allows students and teachers to collect, process, analyze, and visualize real observational data without needing a paid program or professional coding knowledge. This approach is expected to foster digital literacy, an essential competency for the future.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.11
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• pp.6958-6965
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• 2014

This study examined the occurring pattern of potential risky species and the related abiotic factors for port-specific environmental management considering the control of ballast water-induced foreign species at Incheon seaport. From a total of 62 species observed during the study, 13 red-tide and 7 toxic phytoplankton, normally occurring species in Korean waters, occurred from the seasonal investigation at the inner and outer sites of the Incheon seaport from 2007 to 2009. The number of potential risky phytoplankton was relatively high at the outer site of the port during summer and winter. Red-tide species, such as Skeletonema spp., Thalassiosira nordenskioldii, and Paralia sulcata, dominated the total standing crops at the inner site (avg. 72.4%) and outer site (avg. 77.6%) in spring and summer, being positively correlated with the concentrations of total suspended solids (TSS) and pH (p<0.05). In summer, the red-tide species (Skeletonema spp.) and toxic species (Alexandrium catenella, A. tamarense, Dinophysis acuminata and Pseudo-nitzschia spp.) co-dominated (avg. 74.2%) at the inner site, while Skeletonema spp. and P. sulcata predominated (avg. 67.2%) at the outer site. During the study periods, the toxic species were significantly and positively correlated with the chemical oxygen demand (COD), dissolved inorganic nitrogen, silicate and phosphate (p < 0.05). The chlorophyll-a (chl-a) concentration of phytoplankton at the outer site ranged from 1.49 to $5.46{\mu}g/L$ on average, which was 3-5 times higher than that at the inner site in spring, summer and autumn, whereas there was no difference in the concentration between inner (avg. $0.94{\mu}g/L$) and outer (avg. $0.95{\mu}g/L$) sites in winter. In summary, diverse red-tide species dominated and a relatively high chl-a concentration existed at the outer site, whereas a relatively high number of toxic species and low chl-a concentration was observed at the inner site in summer. The potential risky species can outbreak in association with the concentration of nutrients, COD and TSS, suggesting that distinctive management of potential risky species is needed considering the environmental characteristics of Incheon seaport.