• Journal of Veterinary Clinics
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• v.38 no.2
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• pp.75-81
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• 2021

An aquariid nematode, Desportesius invaginatus, was found in the proventriculus of an Egretta garzetta and a Bubulcus ibis from Chuncheon in the Republic of Korea. The worms were identified by light and scanning electron microscopy based on important taxonomic characteristics (body length, esophagus length, cordons, spicules, caudal alae of males, position of the vulva) and then phylogenetically analyzed using the 18S rRNA encoding gene. The nematodes were characterized by a body length of 7.0-8.0 mm in males and 10.2-13.1 mm in females, and two pairs of cordons recurrent in the anterior direction, and cordons were anastomosed by a longitudinal cuticular ridge that externally delimits a longitudinal canal. The widest cuticular plates of cordons bears over 20 posterior spines. The length of the spicules in males was also significantly different. The right spicule measured 742-821 (794) ㎛ in length and 40-45 (42) ㎛ in width, and the left spicule measured 493-556 (541) ㎛ in length and 11-13 (12) ㎛ in width. The caudal alae of males are inflated and vesicular in appearance. The vulva was situated at 56-71 (58.3) ㎛ from the posterior extremity. Although the 18S rRNA sequences of worms were similar to the Synhimantus species, some genetic divergences were observed in comparison. In this study, the worms were recognized with genus Desportesius because genus Desportesius was considered a subgenus of Synhimantus. This is the first record of D. invaginatus in the Republic of Korea.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.43 no.3
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• pp.161-167
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• 1998

Root and shoot development of two rice (Oryza sativa L.) cultivars with different genetic backgrounds was studied with reference to their relative growth. Tongil type (indica-japonica hybrid) cultivar 'Kuemkangbyeo' and japonica cultivar 'Koshihikari' were grown in $5000^{-1}$ a Wagnar pots under flooded condition. Three plants with roots of both cultivars were taken in every phyllochron through the heading stage to record morphological characteristics of shoot and root system. Compared to Koshihikari, Kuemkangbyeo produced more tillers and had greater shoot weight and leaf area per hill. Length and weight of the root system in both cultivars increased exponentially with time. At the same time, root system development was significantly faster in Kuemkangbyeo than in Koshihikari after the panicle initiation stage. As a result, Kuemkangbyeo has a vigorous root system which consists of larger number of nodal roots compared to Koshihikari. Also, the root length and weight per unit leaf area of Kuemkangbyeo were larger than those of Koshihikari in the later half of growing period, which suggests possible higher physiological activity of the root system of Kuemkangbyeo which is known as a high-yielding cultivar. The relationship between root traits (crown root number, total root length, and root dry weight) and shoot traits (leaf area and leaf+culm dry weight) in both cultivars closely showed allometry until the flag leaf stage.

• Journal of The Korean Astronomical Society
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• v.41 no.3
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• pp.77-81
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• 2008

As a continuation of a previous work by Park et al. (2006), we have developed a two-element radio interferometer that can measure both the phase and amplitude of a visibility function. Two small radio telescopes with diameters of 2.3 m are used as before, but this time an external reference oscillator is shared by the two telescopes so that the local oscillator frequencies are identical. We do not use a hardware correlator; instead we record signals from the two telescopes onto a PC and then perform software correlation. Complex visibilities are obtained toward the sun at ${\lambda}\;=\;21\;cm$, for 24 baselines with the use of the earth rotation and positional changes of one element, where the maximum baseline length projected onto UV plane is ${\sim}\;90{\lambda}$. As expected, the visibility amplitude decreases with the baseline length, while the phase is almost constant. The image obtained by the Fourier transformation of the visibility function nicely delineates the sun, which is barely resolved due to the limited baseline length. The experiment demonstrates that this system can be used as a "toy" interferometer at least for the education of (under)graduate students.

• Applied Microscopy
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• v.50
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• pp.18.1-18.7
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• 2020

The olfactory anatomy and histology of Lethenteron reissneri were researched using a stereo microscope, a light microscope, and a scanning electron microscope. As in other lampreys, it shows same characters as follows: i) a single olfactory organ, ii) a single tubular nostril, iii) a single olfactory chamber with gourd-like form, iv) a nasal valve, v) a nasopharyngeal pouch, vi) a sensory epithelium (SE) of continuous distribution, vii) a supporting cells with numerous long cilia, viii) an accessory olfactory organ. However, the description of a pseudostratified columnar layer in the SE and Non SE is a first record, not reported in sea lamprey Petromyzon marinus. In particular, both 19 to 20 lamellae in number and olfactory receptor neuron's quarter ciliary length of the knob diameter differ from those of P. marinus. From these results, it might be considered that the olfactory organ of L. reissneri shows well adaptive structure of a primitive fish to slow flowing water with gravel, pebbles, and sand and a hiding habit into sand bottom at daytime. The lamellar number and neuron's ciliary length may be a meaningful taxonomic character for the class Petromyzonida.

• Korean Journal of Ichthyology
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• v.27 no.1
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• pp.55-59
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• 2015

A single specimen (705 mm in standard length) of Lampris guttatus ($Br{\ddot{u}}nnich$, 1788), belonging to the family Lampridae, was firstly collected from the coast of Samcheok, East Sea, Korea in November 2014. This species was characterized by having oval shaped body, vivid scarlet fins and jaw and pale white spots on body irregularly. We propose a new Korean name, "Buk-pyeong-chi-gwa", "Buk-pyeong-chi-sok" and "Buk-pyeong-chi" for the family, genus and species, respectively.

• Korean Journal of Ichthyology
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• v.27 no.1
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• pp.45-49
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• 2015

A single specimen (192 cm total length, TL) of the Pacific sleeper shark, Somniosus pacificus, belonging to the family Somniosidae, order Squaliformes, was firstly collected from the west margin of the East Sea, Korea in February 2008. This specimen was characterized by having interdorsal space, being less than the distance between the snout and first gill opening; and the distance between the snout and first dorsal fin origin more than 45% TL; head and body has overall dark brownish. The new Korean name "Jam-sang-eo-gwa" is proposed for the family Somniosidae, and "Jam-sang-eo-sok" for the genus Somniosus, and "Jat-bit-jam-sang-eo" for the species S. pacificus.

• Korean Journal of Ichthyology
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• v.21 no.4
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• pp.307-310
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• 2009

A specimen (862.3 mm standard length) of Pisodonophis cancrivorus (Richardson, 1848), family Ophichthidae, was first collected from the coast of Uljin-gun in Gyeongsangbuk-do, Korea in September 2008. This species is characterized by the following: fleshy protrusions of upper jaw in the front and rear of the posterior nostril, 3~5 irregular rows of granular teeth in bands on maxilla, mandible and vomer, and origin of dorsal fin above the middle of the pectoral fin. Based on the fleshy protrusions found on its upper jaw, a new Korean name "dol-gi-ba-da-baem" has been proposed for this species.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.2
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• pp.109-117
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• 2018

The experimental results are presented of an autonomous flight algorithm of a foldable quadcopter with airdrop launching functions. A foldable wing structure enabled the quadcopter to be inserted into a rocket container with limited space. The foldable quadcopter was then separated from the rocket in the air. The flight pattern was tracked using a global positioning system (GPS) with various sensors, including an inertial measurement unit (IMU) module until a designated target position was reached. Extensive field tests were conducted through an international rocket competition, ARLISS 2017, which was held in Black Rock Desert, Nevada, USA. The flight trajectory record of the experiments is stored in electrically erasable programmable read-only memory (EEPROM) embedded in the main control unit. The flight record confirmed that the quadcopter successfully separated from the rocket, executed flight toward the target for a certain length of time, and stably landed on the ground.

• Animal Systematics, Evolution and Diversity
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• v.9 no.1
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• pp.51-59
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• 1993

A gobiid fish, Parioglossus dotui Tomiyama is described from 359 specimens collected at Cheju-do and Pusan, in August 1994 of 1986. This is the first definitive record of the species in the Korean waters. Parioglossus dotui having a small-sized body usually is found swimming in schools. The branchiostegals are 5 in number on each side. It grows up to 40mm in total length. Most of ventral fins are separated and connected with rudimentray membrane. In this species, the lateral line were indistincet or absent. The caudal fin slightly emarginates or truncates in both sexes, with a dark spot at the border of the base. It Inhabits inlet waters and estuaries of rivers. "Deungsul mang-dug" is proposed as Korean name of this species.

• Fisheries and Aquatic Sciences
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• v.17 no.2
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• pp.263-267
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• 2014

A single juvenile pomacentrid specimen (5.9 mm standard length) was collected from the Korea Strait in October 2010. The specimen is characterized by punctate-stellate melanophores scattered on the operculum and dorso-ventral region in front of the caudal peduncle, the lack of melanophores on the posterior end of the anal fin base, the presence of 14 spines and 14 soft rays on the dorsal fin, and the presence of 2 spines and 12 soft rays on the anal fin. A molecular analysis based on mitochondrial DNA 16S rRNA sequences showed that this specimen is closely related to adult Chromis mirationis (d = 0.002), but that it differs from Chromis notata (d = 0.017). Juvenile C. mirationis differ from juvenile C. notata in having no melanophores on the posterior end of the anal fin base. We propose a new Korean name, "tti-ja-ri-dom" for C. mirationis.