• Korean Journal of Fisheries and Aquatic Sciences
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• v.51 no.5
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• pp.595-599
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• 2018

One specimen (181.0 cm; TL, total length) of Echinorhinus cookei was collected from Busan, Korea in 2014 using gill net. Echinorhinus cookei was characterized by having no anal fin, no spine at dorsal fin and numerous small dermal denticles at the placoid scale. This species is very similar to the congeneric species, E. brucus, but differed in the shape of placoid scale (star in E. cookei vs. round in E. brucus) and distribution of placoid scale (separated in E. cookei vs. slightly overlapped in E. brucus). We adopted the Korean name, Ga-si-bi-neul-sang-eo, for E. cookei, after Kim and Ryu (2017).

• Korean Journal of Ichthyology
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• v.26 no.4
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• pp.331-335
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• 2014

A single specimen of the stone cockscomb, Alectrias alectrolophus (Pallas, 1811) was collected from off Gangneung-si, East Sea, Korea. The present Korean specimen is characterized in having a dermal crest on dorsal median line of head, LXIII dorsal fin rays, I, 44 anal fin rays, 68 vertebrae, slender and flexible dorsal spines in its anterior parts, and scales on the posterior portion of body, and fused gill membranes forming a free fold across the isthmus. We report A. alectrolophus based on a single specimen collected from the Korean water as the first record from Korea.

• The Korean Journal of Zoology
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• v.33 no.2
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• pp.238-240
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• 1990

A gobjoid fish, Pierogobius zacalies is described from three spedmens colleded in Songjong-dong, Pusan-si, on February 10, 1989. This Is the first definItive record in Korean waters. This fish is disdnguished from the other species of the genus Pierogobius by the combinadon of the following charaders: lateral-line scales > 113, soft dorsal fin rays VIII, i-24-25, soft anal fin rays i-24-25, and 5 dark-brown vertical broad band on the body. "Dasotdonggal-- mang-dug is proposed as Korean name of this species.cies.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.5
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• pp.736-741
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• 2022

A single specimen (91.5 cm standard length) of the salmonid species, Oncorhynchus tshawytscha (Walbaum, 1792) was collected on April 19, 2022 in Sokcho-si, Gangwon-do, Korea. O. tshawytscha has the following morphological characteristics: base of lower jaw teeth is black, black spots are scattered on the dorsal section of body, and the edge of caudal fin is black. Although the species is morphologically similar to Oncorhynchus kisutch, O. tshawytscha differs from it in having black spots on the caudal fin. Molecular analysis results based on mitochondrial cytochrome c oxidase subunit I (COI) sequences showed that our specimen perfectly matched with the COI sequences of O. tshawytscha registered at the NCBI. Therefore, we suggest the new Korean name 'Wang-yeon-eo' for O. tshawytscha.

• Journal of Fisheries and Marine Sciences Education
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• v.6 no.1
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• pp.58-76
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• 1994

Heat transfer and pressure drop measurements are made on low integral-fin tubes in turbulent water flow condition. The integral-fin tubes investigated in this paper are nominally 19mm in diameter. Eight tubes have been used with trapezoidally shaped integral-fins having fin density from 748 to 1654 fpm and 10, 30 grooves. Plain tube having same diameter as finned tube is also tested for comparison. Experiments are carried out using R-11 as working fluid. The refrigerant condensates at a saturation state of $30^{\circ}C$ on the outside tube surface cooled by coolant. The amount of noncondensable gases present in the test loop is reduced to a negligible value by repeated purging. For a given heat input to the boiler and given cooling water flow rate, all test data are taken on steady state. The heat transfer loop is used for testing single long tubes and cooling water is pumped from a storage tank through filters and flowmeters to the horizontal test section where it is heated by steam condensing on the outside of the tube. The pressure drop across the test section is measured by means of pressure gauge and manometer. Each tube tested is cleaned with sodium dichromate pickling solution and well rinsed with water prior to installation in the test section. The results obtained in this study is as follows : 1. Based on inside diameter and nominal inside area, heat transfer of finned tube is enhanced up to 4 times as that of a plain tube at constant Reynolds number and up to 2 times at constant pumping power. 2. Friction factors are up to 1.6~2.1 times those of plain tube. 3. At a given Reynolds number, Nusselt number decrease with increasing pitch to diameter. 4. The constant pumping power ratio for low integral-fin tubes increase directly with the effective area to the nominal area ratio, and with the effective area diameter ratio.

• Korean Journal of Ichthyology
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• v.33 no.3
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• pp.167-176
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• 2021

This study was carried out to clarify the egg, larvae and juveniles development of Abbottina springeri. For the experiments, the matured adults were collected at the Seowon-cheon, Dangjin-si, Chungcheongnam-do, in Korea. The amount of spawning of female A. springeri was about 1,225~2,100 (1,662±437, n=10). The fertilized eggs were circular in shape and 1.05~1.13 (1.08±0.02, n=30) mm in diameter. The hatching time was required 72 hours to 80 hours after fertilization under water temperature of 22℃. The newly hatched larvae were 2.10~2.23 (2.16±0.04, n=10) mm in total length and had egg yolk in the abdomen but the mouth was not opened. At 5 days after hatching, the preflexion larvae were 3.19~3.30 (3.24±0.03, n=10) mm in total length and the most of yolk-sac was absorbed. At the 15 days after hatching, the flexion larvae were 4.97~5.30 (5.13±0.12, n=10) mm in total length and the tip of the caudal fin was began to bend upward. At the 25 days after hatching, the postflexion larvae were 8.97~9.60 (9.44±0.16, n=10) mm in total length and the tip of the caudal fin was bent at 45°. At the 35 days after hatching, the juvenile were 12.0~13.5 (12.7±0.53, n=10) mm in total length and all fin-rays (iii7 dorsal fin, iii6 anal fin, i7 ventral fins) were reached a constant number of each part.

• Korean Journal of Ichthyology
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• v.19 no.3
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• pp.246-252
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• 2007

Two specimens (56.3~61.1 mm SL) of the serranid fish, Chelidoperca pleurospilus and 21 specimens (34.0~93.6 mm SL) of the pinguipedid fish, Parapercis muronis were collected around Jeju Island, southern Korea. C. pleurospilus is characterized by having five dark blotches along lateral line, truncated caudal fin, and scaleless interorbital space. P. muronis is characterized by having five oblique dark bands on body side, five spines on dorsal fin, and no notch between spinous and soft-rayed portions of dorsal fin. We describe these specimens as the first record from Korea, and propose the new Korean name, "Byeol-gak-si-dom" for the former and "Da-seosjul-yang-dong-mi-ri" for the latter.

• Korean Journal of Ichthyology
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• v.25 no.1
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• pp.46-49
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• 2013

A single specimen (373.2 mm SL) of the snailfish Careproctus colletti was collected by gill-net at Donghae-si, East Sea, Korea. This species is characterized by having the slender and stick-like teeth, lower end of gill opening not reaching to upper origin of pectoral fin, rays of lower part of pectoral fin long, reaching behind anus and margins of dorsal and anal fin dark. We described it as the first record to Korean fish fauna, and proposed the new Korean name "Meok-bun-hong-kkom-chi" for this species.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.107.1-107.1
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• 2014

We have developed and commercialize a time-of-flight - medium energy ion scattering spectrometry (TOF-MEIS) system (model MEIS-K120). MEIS-K120 adapted a large solid acceptance angle detector that results in high collection efficiency, minimized ion beam damage while maintaining a similar energy resolution. In addition, TOF analyzer regards neutrals same to ions which removes the ion neutralization problems in absolute quantitative analysis. A TOF-MEIS system achieves $7{\times}10^{-3}$ energy resolution by utilizing a pulsed ion beam with a pulse width 350 ps and a TOF delay-line-detector with a time resolution of about 85 ps. TOF-MEIS spectra were obtained using 100 keV $He^+$ ions with an ion beam diameter of $10{\mu}m$ with ion dose $1{\times}10^{16}$ in ordinary experimental condition. Among TOF-MEIS applications, we report the quantitative compositional profiling of 3~5 nm CdSe/ZnS QDs, As depth profile and substitutional As ratio of As implanted/annealed Si, Ionic Critical Dimension (CD) for FinFET, Direct Recoil (DR) analysis of hydrogen in diamond like carbon (DLC) and InxGayZnzOn on glass substrate.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.3
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• pp.302-306
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• 2012

Bacterial cellulose based actuator with large displacement was developed for biomimetic robots. Bacterial cellulose has 3D nanostructure with high porosity which was composed of the nanofibers. Freeze dried bacterial cellulose was dipped into ionic liquid solution such as 1-butyl-3-methylimidazolium(BMIMCl) to enhance the actuation performance due to increase the ionexchange capacity and ionic conductivity. And Poly(3,4-ethylenedioxythiophene)-poly (styrnenesulfonate)(PEDOT:PSS) was used for the electrodes of both side of bacterial cellulose actuator by dipping and drying method. The FT-IR and XRD were conducted to examine the electrochemical changes of developed bacterial cellulose actuator. The biomimetic caudal fin was designed using bacterial cellulose actuator and PDMS to verify the possibility for biomimetic robot. The step and harmonic response were conducted to evaluate the performance of developed biomimetic actuator.