• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.9
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• pp.46-51
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• 2013

In this paper, the optimum placement and shape of UHF antenna on the unmanned aerial vehicle (UAV) are analyzed by using the electromagnetic (EM) simulation on the various locations. The FEKO was used for the EM-simulation. In order to reduce the complexity of simulation and minimize the runtime and memory usage, the composite aircraft structure is simplified as the PEC model excluding the radome structure. The simulation was performed on the wing and ventral fin of UAV, and the antenna shape used the monopole, dipole, and bent monopole antennas. When the monopole antenna is mounted under the wing, two antennas need to be mounted under the right and left wings, and those antennas have to be switched as the direction of UAV wing to the line of sight (LOS) data-link (DL) ground antenna. In the case of mounting under the ventral fin, one antenna can be used regardless of the direction of UAV wing to the LOS DL ground antenna. Also, the antenna gain is improved by the blockage reduction. The antenna gain is further improved by using the bent monopole antenna. The optimum solution of UHF antenna placement and shape on UAV is to mount the bent monopole antenna under the ventral fin.

• Fisheries and Aquatic Sciences
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• v.25 no.9
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• pp.489-497
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• 2022

The first specimen (54.8 mm standard length) of Ernogrammus zhirmunskii Markevich & Kharin, 2011, belonging to the family Stichaeidae, was recorded in Dokdo, East Sea, Korea on July 26, 2021. This species was characterized by a single ventral lateral-line canal from the posterior margin of the pelvic-fin base extending to the anus and one or two rigid spines on the posterior part of the anal fin. This species is similar to Ernogrammus hexagrammus and Ernogrammus walkeri but differs in the number of ventral lateral-line canal present, with E. zhirmunskii consisting of one (unpaired) ventral lateral-line canal compared to other two Ernogrammus species, which have a pair of parallel ventral lateral-line canal. For further analysis of species identification, a partial gene sequence from the mitochondrial DNA cytochrome oxidase subunit I (554 bp) of E. zhirmunskii was obtained for the first time. This study documents the first record of E. zhirmunskii in Korean waters and proposes the new Korean name of 'Il-gob-julbe-do-la-chi' for the species.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.9 no.4
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• pp.273-280
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• 1976

Morphological changes of early larval stages of Lophius litulon (Jordan) are described based on 861 individuals collected at the intertidal zone at Haeundae, Busan, on the 20th of June, 1976. Particular emphasis is paid on the development of dorsal spinous rays, ventral fin rays, chromatophore patterns, alimentary canal, gills, branchiostegal rays and teeth. The premordial spinous fin ray of the first dorsal fin appears at the newly hatched larva of around 2.70mm in total length, the second spinous ray at around 5.82mm, and the third spinous ray at around 6.45 nm. Premordial fin rays which develope as a semicircle to cudgel form of the ventral fin appear posterior to the pectoral fin at the larva of around 2.70mm in total length. When the larvae grow up to 6.35mm in total length, the length of the ventral fin is more or less half of the total length of the body. In the early stages$(2.70\~3.75mm)$ melanophores are scattered irregularly on the tail . In the later stages(4.25mm) melanophores are aggregated to form three black spots on medio-lateral part of the tail. The newly hatched larvae have the premordial alimentary canal with mouth and intestine. With decreasing yolk mass the intestine appears more distinctly with curvature, and mouth seems to open. Gills appear at the larvae of 6.35mm in total length; branchiostegal rays appear at the larvae of 6.45mm. Teeth appear at the larvae of 6.25mm.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.4
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• pp.687-689
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• 1997

For identification of morphometric characteristics in rainbow trout, Oncorhynchus mykiss, coho salmon, O. kisutch, and their allotriploid, twenty one body traits were measured, and the ratios of each trait to fork length, length from postorbital to the origin of caudal fin and head length were calculated. The ratios of fin length to fin height in anal, dorsal and adipose fins showed significant differences among these two species and their allotriploid $(p\leq0.01)$. Allotriploid could be distinguished easily from two parents species in the ratios of length of origin of ventral fin to fork length and anal fin length to anal fin height.

• Fisheries and Aquatic Sciences
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• v.13 no.3
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• pp.257-259
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• 2010

This is the first report of Snyderina yamanokami, from the subfamily Tetraroginae of the family Scorpaenidae, collected in Korea. The specimen (175.3 mm long) was caught in the coastal waters of Jeju Island on a commercial longline hook on 9 September 2009. This species is characterized by the following morphological traits: 9-11 dorsal fin rays, 5-6 anal fin rays, 13-15 pectoral fin rays, 5 ventral fin rays, pectoral fin tip reaching or extending past the origin of the anal fin, palatines toothless, and four dark spots on the middle of the body. We suggest a new Korean name, "Keun-mi-yeok-chi," for S. yamanokami.

• Korean Journal of Ichthyology
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• v.21 no.3
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• pp.208-213
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• 2009

Histological examination of an individual of the Korean slender gudgeon Squalidus gracilis majimae having cutaneous albinism produced rarely in the wild was made and compared with a normal individual. The external body of the albino was colorless, differing from the normal individual, which has dense brownish black spots over its body surface. To make it clear through histological study, we observed eight skin regions: dorsal, lateral, ventral, upper caudal peduncle, lower caudal peduncle, dorsal fin, anal fin, and the eyes. These regional skins were the same in fundamental structure between albinic and normal gudgeon, but there were significant differences in distribution and development of pigment cells (melanins). In the normal gudgeon, the pigment cells were well developed over the regional skins except on the skin from the ventral region. However, it was confirmed in the albino that the pigment cells were vestigial over the upper regions of the eye and body but absent in the ventral region, lower caudal peduncle, and anal fin.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.8 no.4
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• pp.225-233
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• 1975

Morphological changes of early post-larval and young stages of Chasmichthys dolichognathus HILGEnDORF (Family Gobiidae) have been studied based on the samples of 953 individuals collected in June 1968, July 1969 and July 1971. Particular emphasis was paid on the development of fin rays, chromatophore patterns and ventral fins. The primordial fin rays of the first dorsal fin appear in the post-larvae of around 8.0 mm in total length, and dorsal fin fully develops in the larvae of around 9.2 mm. In the early young stages of 17.0 mm in total length fin rays have completely developed. According to chromatophore patterns the larvae are grouped into three successive groups. The larvae at the early stages of 6.3-14.2 mm have melanophores on the whole dorsal surface, the posterior ventro-lateral part of the tail and the basal part of the caudal fin. In the later larval stages of 17.0-24.4 mm a group of melanophores are added on medio-lateral part of the tail. These melanophores extend anteriorly and eventually cover the medio-lateral part of the whole body. In the early young stages of 97.2-34.8 mm the chromatophores cover the whole body surface in cloudy and H-shaped patterns. The chromatophore patterns of this stage are distinctive as generic characters of the fish. Fin membranes of the ventral fin appear in the post-larval stage (ca. 7.4 mm), and the primordial fin rays develop in the late post-larval stages (ca. 14.2 mm). The fin rays develop into a complete sucker in the young fish stage of around 30.0 mm in total length.

• Korean Journal of Ichthyology
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• v.13 no.2
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• pp.117-122
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• 2001

Three species, Gymnogobius urotaenia, G. sp. 1 and G. sp. 2, collected at Hosan-river, Hosan-ri, Samcheock-si, Gangwon-do, Korea, were examined for the study of sexual dimorphism. The three species have peculiar nuptial pigmentation during the breeding season: all females of the three species showed an intense black coloration on the ventral part of the head, the pelvic fin, the anal fin and the margin of the first dorsal fin. There was a difference between G. sp. 1 and the other two species in 1/3 from margin of first dorsal fin. Namely, G. sp. 1 showed an intense black coloration, whereas the other two species had an intense yellow coloration. All females of the three species showed the same, intensely yellow coloration in the ventral part of the body. Males of G. urotaenia and G. sp. 2 had almost the same nuptial pigmentation, however the former showed diffuse black coloration in the anal fin, whereas the latter had an intensely black anal fin. Males of G. sp. 1 differed from those of the other two species in their yellow color on the ventral part of the head, the pelvic f ins, the anal fin, in contrast to the diffuse black coloration in those parts in the other species. The genital papilla of males was triangle-shaped, but that of females was heart-shaped. Significant differences between sexes include: G. urotaenia, 7 characters (body depth, head length, snout length, upper jaw length, head depth, pectoral fin ray length, eye diameter); G. sp. 1, 11 characters (body depth, head length, caudal peduncle length, caudal peduncle depth, snout length, upper jaw length, head width, head depth, anal fin ray length, pectoral fin ray length and caudal fin ray length); G. sp. 2, 10 characters (body depth, head length, caudal peduncle depth, snout length, upper jaw length, head width, anal fin ray length, pectoral f in ray length, caudal fin ray length and eye diameter). Of the 5 characters which showed differences in all three species (body depth, head length, snout length, upper jaw length and pectoral fin ray length), females had higher values than males only in body depth, whereas males values in all other characters. The upper jaw length was the most distinctive sexually dimorphic feature, the upper jaw extended beyond the posterior margin of the eyes (p<0.001) in males but not in females.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.4
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• pp.569-574
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• 2023

A single specimen (30.35 mm standard length) of Ptereleotris evides was collected from the southern coast of Jejudo Island, Korea, in September 2017 during a skin diving outing. Ptereleotris evides is characterized by having a slightly elongated body, six spines on the 1^st dorsal fin, one spine and 25 soft rays on the 2^nd dorsal fin, 22 pectoral fin rays, one spine and four soft rays on the pelvic fin, one spine and 25 soft rays on the anal fin, and no disc in pelvic fin. This species differs from the congeneric species, P. hanae and P. heteroptera in having no elongated rays on the caudal fin and a black spot at the ventral margin of the caudal peduncle, respectively. Molecular analysis results based on mitochondrial DNA cytochrome c oxidase subunit I (COI) sequences showed that our specimen almost corresponded to P. evides (99.82%) sequences from registered at the NCBI. As this is the first record of P. evides in Korean waters, we propose a new Korean name for it, "Ga-mak-cheong-hwang-mun-jeol".

• Korean Journal of Ichthyology
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• v.28 no.2
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• pp.110-115
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• 2016

This study was conducted in order to investigate the growth and morphological development of Cypselurus hiraii larvae and to obtain basic data for taxonomic research. Specimens for this study were collected using a scoop net (aperture Ø60 cm) at the Geomun Island in Yeosu-si, Jollanam-do in July and August of 2013, and the mean water temperature was $20.6{\pm}1.84^{\circ}C$ and the mean salinity was $32.1{\pm}0.46$‰ during the collection. In post-larvae of total length 9.58~9.69 mm (average $9.63{\pm}0.04mm$, n=5), the mouth was opened, and the maxilla was shorter than the mandible. The length of the dorsal fin did not exceed that of the ventral fin, and the dorsal fin was on the same line as that of the ventral fin. In post-larvae of total length 18.0~18.5 mm (average $18.2{\pm}0.22mm$, n=5), with the growth accelerated, the pectoral fin was developed broadly and their caudal fin was differentiated into the heterocercal tail. These characteristics suggest the development of swimming ability and resultant active feeding activities. In post-larvae of total length 22.4~23.0 mm (average $22.7{\pm}0.21mm$, n=5), striped melanophores deposited in the pectoral fin, and small spot-like melanophores expanded in the processes formed on the mandible. The dorsal and anal fins were on the same line, and the anal fin was situated behind the dorsal fin.