• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.4
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• pp.478-483
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• 2022

A single specimen (522.0 mm in total length) of the family Muraenidae, collected from the waters off south-western Jeju-do Island in November 2021, was identified as Echidna nebulosa on the basis of morphological and molecular methods (DNA barcoding). This species is characterized by several morphological traits as follows: 10 rounded molar, median intermaxillary, and vomerine teeth; 4 predorsal vertebrae, 50 preanal vertebrae and 123 total vertebrae; and a pale background color with two rows of 17-20 blackish brown starry blotches along the head and body. As this is the first record of E. nebulosa in Korea, we propose the new Korean names, "Dung-Geun-Ni-Gom-Chi-Sog" for the genus Echidna, and "Beol-Kkok-Gom-Chi" for E. nebulosa.

• 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 Environment and Ecology
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• v.30 no.4
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• pp.745-750
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• 2016

Morphological characteristics and population characteristics of the Rhynchocypris kumgangensis were investigated at Taehwa River from April 2014 to April 2015. This is the first record on R. kumgangensis not only from Guksu stream (the upstream region of Taehwa River, Ulsan-si Ulchu-gun Beomseo-eup Kuksu-ri) but also from the stream flowing into the Gangneungnamdae stream, in the southern part of East Sea, Korea. The morphometric characteristics of R. kumgangensis in the Taehwa River and the Han River are very similar except that the population at Taehwa River showed shorter caudal peduncle length than caudal peduncle depth when compared with the population at Han River. In terms of meristic character the population at Taehwa River showed fewer numbers of scales at the lateral line, above the lateral line and below the lateral line. Other than that, the two populations showed the same meristic characters. The fish cohabiting with R. kumgangensis mainly composed of Zacco platypus (25.2%), Rhynchocypris oxycephalus (24.1%) and Zacco koreanus (21.8%). Length frequency distribution analysis indicated that the length of the group ranged between 45~65 mm and the average length was 54.3 mm. Calculation of the length-weight relation of R. kumgangensis showed the value of constant a as 0.000002 and b as 3.34, and the Condition factor (K) was 1.10 an on average.

• Korean Journal of Environment and Ecology
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• v.31 no.2
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• pp.166-173
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• 2017

Morphological and population characteristics of the Cottus koreanus were investigated at Hoam stream from October 2015 and April 2016. This is the first record on C. koreanus not only from Hoam stream (the upstream region of Daejong stream, Gyeongsangbuk-do Gyeongju-si Yangbuk-myeon Hoam-ri) but also from the stream flowing into the Samcheogosip stream, in the southern part of East Sea, Korea. The distribution of C. koreanus ranged from Girim temple to Yongyeon waterfall, about 1.2 km, and the water surface were about $3,600m^2$. The population size was assumed to 1,656 individual number, 46 object per $100m^2$. The morphometric characteristics of C. koreanus in the Hoam stream and the Han river are very similar except that the population at Hoam stream shorter head length, ventral fin ray length, pectoral fin ray length and mouth width when compared with the population at Han river. Other than that, the two populations showed the same meristic characters. Frequency analysis of total length indicated that the group with 40~59 mm in total length was one year old, the 60~79 mm was two years old, and the group over 80 mm was three years old. The average number of eggs in the ovaries was estimated as 361 (239~468) per matured female. The number of matured eggs size in ovaries was $2.6{\pm}0.21$ (23.~3.1) mm and this species was large eggs type. Calculation of the length-weight relation of C. koreanus showed the value of constant a as 0.00001 and b as 3.01, and the Condition factor (K) was 1.26 an on average.

• Korean Journal of Applied Biomechanics
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• v.23 no.4
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• pp.295-306
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• 2013

The purpose of this study was to provide high school male shot putters training methods of gliding and delivery motion through comparative analysis of kinematic characteristics. To accomplish this purpose, three dimensional motion analysis was performed for the subjects(PKC, KKH, YDL) who participated in high school male shot putter competition on 92nd (2011), 93rd (2013) National Sports Festival. The subjects were filmed by four Sony HXR-MC2000 video cameras with 60 fields/s. The three-dimensional kinematic data of the glide, conversion and delivery phase were obtained by Kwon3d 3.1 version. The data of the shoulder rotational angles and projection angles were calculated with Matlab R2009a. The following conclusions had been made. With the analysis of the gliding and stance length ratio, the gliding length was shorter at the TG than the SG with short-long technique but the gliding and stance length ratio was 46.8:53.2% respectively. The deviation of the shots trajectory from APSS(Athlete-plus-shot-system) revealed that the PKC showed similar to "n-a-b-c-I" of skilled S-shape type, KKH and YDL showed "n-a-d-f-I'" of unskilled type. Furthermore, they showed smaller radial distance from the central axis of the APSS and the shots were away from the linear trajectory. From this characteristics, The PKC who performed more TG than SG had shorter glide with S-shape of APSS(skilled type) showed the better record than others with technical skill. But KKH and YDL had bigger glide ratio with "n-a-d-f-I'" of unskilled type and improved their records with technical factor. The projection factor had an effect on the record directly. Because PKC maintained more lower glide and transition posture with momentum transfer through COG's rapid horizontal velocity respectively the subject possessed the characteristics of high horizontal and vertical velocity with large turning radius from shot putter to APSS.

• Korean Journal of Ichthyology
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• v.28 no.1
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• pp.52-56
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• 2016

A single specimen (700 mm in disc length) of Plesiobatis daviesi, belonging to the family Plesiobatididae, was firstly collected in the north-eastern coastal waters of Jejudo Island, Korea by using a bottom trawl on 24 October 2010. This species was characterized by having five pairs of gill openings, tail with one to three large spines, long snout length, long caudal fin, and pleated margin of nasal curtain. It is morphologically similar to Urolophus aurantiacus, but the former is distinguished from the latter by having longer caudal fin and snout length. We add P. daviesi to the Korean fish fauna and suggest the new Korean names, "Gin-kko-ri-huin-ga-o-ri-gwa", "Gin-kko-ri-huin-ga-o-ri-sok" and "Gin-kko-ri-huin-ga-o-ri" for the family, genus and species, respectively.

• Fisheries and Aquatic Sciences
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• v.18 no.3
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• pp.297-300
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• 2015

This is the first report of Champsodon longipinnis (Champsodontidae) collected from Korea. The specimen (100.9 mm in standard length) was caught by a bottom trawl in the coastal waters off Busan, Korea. This species is characterized by the following morphological traits: body with small denticulate scales except abdomen around pelvic fin base; posterior end of maxilla extending beyond margin of eye; dark pigmentation on most of the first dorsal fin, upper half of the first to the fourth soft ray of the second dorsal fin, and partial upper lobe of caudal fin. We add C. longipinnis to the Korean fish fauna and suggest a new Korean name, "Jeom-ak-eo-chi," for the species.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• v.y2005m4
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• pp.343-346
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• 2005

Three dimensional structures of detonation wave propagating through a square-shaped duct were investigated using computational method and parallel processing. Inviscid fluid dynamics equations coupled with $variable-{\gamma}$ formulation and simplified one-step Arrhenius chemical reaction model were analysed by MUSCL-type TVD scheme and four stage Runge-Kutta time integration. The unsteady computational results in three dimension show the detailed mechanism of transverse mode and diagonal mode of detonation wave instabilities resulting same cell length but different cell width in smoked-foil record.

• 한국전산유체공학회:학술대회논문집
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• 2005.10a
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• pp.151-155
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• 2005

Three-dimensional structures of unsteady detonation wave propagating through a square-shaped tube is studied using computational method and parallel processing. Inviscid fluid dynamics equations coupled with variable-${\gamma}$ formulation and simplified one-step Arrhenius chemical reaction model were analysed by a MUSCL-type TVD scheme and four stage Runge-Kutta time integration. Results in three dimension show the two unsteady detonation wave propagating mode, the Rectangular and diagonal mode of detonation wave instabilities. Two different modes of instability showed the same cell length but different cell width and the geometric similarities in smoked-foil record.

• Animal Systematics, Evolution and Diversity
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• v.28 no.1
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• pp.54-58
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• 2012

This study dealt with cumacean specimens collected from the shallow waters of the South Sea and East Sea, Korea. Campylaspis fusiformis Gam$\hat{o}$, 1960 belonging to the family Nannastacidae is newly recorded to Korean fauna. This species resembles C. pumila and C. striata in having a similar body form and a pair of narrow lateral sulcuses on the carapace, but it is easily distinguished from them by the dactylus of the pereopod 2 which is more than 3.5 times the length of the propodus and bears many setae (about 20) on the surface. This species mainly occurs in the Korean and Japanese waters.