• Korean Journal of Ichthyology
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• v.21 no.4
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• pp.273-282
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• 2009

The taxonomic review of the family Trachipteridae was carried out based on the Trachipterus ishikawae (7 specimens), Zu cristatus (4 specimens), Desmodema polystictum (2 specimens) collected from the East Sea, South Sea and adjacent waters of Jeju Island of Korea from June 2006 to August 2008. Among them, D. polystictum was revealed as an unrecorded species from Korea, being characterized by the following characters: the ventral edge smooth; body color silvery white with a lot of large dark rounded spot. We proposed the new Korean name of the genus Desmodema as "Jeom-tu-ra-chi-sog", D. polystictum as "Jeom-tu-ra-chi". Z. cristatus has a elongated first six dorsal fin and pelvic fin rays. T. ishikawae has a row of sharp tubercles along the ventral edge, and straightly elongated body form. In meristic characters, the number of dorsal fin rays were 178~195 in T. ishikawae, 137~148 in Z. cristatus and 125~130 in D. polystictum, the number of vertebrae were well distinguished among three species; T. ishikawae (80~83), D. polystictum (72~74) and Z. cristatus (65~68).

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.25 no.6
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• pp.422-432
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• 2013

A System Identification method to develop parametric models linking free surface elevation and wave pressure is presented and two models are built allowing for either wave pressure or free surface elevation simulation. Linear, time invariant model structures with static nonlinearities are assumed and solutions are sought in a form of autoregressive model with extra input (ARX). An arbitrary chosen free-surface elevation and wave pressure dataset is used for estimation of the models, which are subsequently verified against datasets with similar pressure gauge depth but different free-surface elevation spectra due to different meteorological conditions. It is shown that free-surface simulation using System Identification methods can perform better than traditional linear transfer function derived from linear wave theory (LTF), while wave pressure simulation quality using presented methods is generally similar to that obtained with corrected LTF.

• Korean Journal of Ichthyology
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• v.12 no.4
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• pp.236-243
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• 2000

The purpose of present the study was to describe the spawning behavior and early life history of the grass puffer, Takifugu niphobles. The grass puffer was caught at the spawning ground on the coast Dolsan, Korea from May to the 1998. Artificial fertilization was carried out to get fertilied eggs. Spawning season was from the end of May to the beginning of July on the coast of the Dolsan, Korea. Form 2~6 days before the spring tide the aduct males and females began to aggregate in the shore water, and they spawned in the upper part of intertidal zone exposed to air among pebble stone. The fertilized eggs were demersal, transparent and spherical in shape, and its diameter were 0.87~0.95 mm with several oil globules of 0.0014~0.0540 mm. Hatching began about 146 hours after fertilization under water temperature $21.2{\sim}22.3^{\circ}C$. The newly-hatched larva was 2.02~2.24 mm in total length (TL, mean: 2.14 mm), with 22~24(8~9+14~15) myotomes, and mouth and anus was not yet open. In 3 days after hatching it was measured 2.64~2.93 mm in TL (mean: 2.76 mm), and yolk sac was completely absorbed and transformed to postlarval stage. In 15 days after hatching it was measured 4.43~4.82mm in TL (mean: 4.59mm), and the caudal notochord flexion started. The larvae reached the juvenile stage in 28 days after hatching and attained 7.55~7.65mm in TL (mean: 7.60mm), and all fin-rays were formed.

• Korean Journal of Ichthyology
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• v.4 no.2
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• pp.44-54
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• 1992

The blenniid fish, Pictiblennius yatabei(Jordan et Snyder) is ditributed in the central and southern Japan and southern Korea. The fish grows to a maximum size of 9cm in total length, and it seems to be matured in two years. Sex dimorphisms of the fish appear in the crest and the anal fin. Five egg masses of the fish were collected in Tongyoung Bay near Kyeong Nam on June 16 and 20, 1991. The eggs were laid on inner surface of empty shells of the oyster, Crassotrea gigas and blue mussel, Mytilus edulis. Each egg mass was guarded by the male parent. Numbers of eggs in each of masses were as about 450~1000.The eggs were spherical but somewhat oval in shape and ranged from 0.72 to 0.80mm in longer axis and from 0.55 to 0.65mm in shorter axis. Each egg was provided with an adhesive pedestal. Hatching took place in 105 hours after formation of embyo at the water temperature varying from 20.0 to $21.4^{\circ}C$. Melanophores appearing on the yolk remarkably changed in form during the embryonic development.The newly hatched larvae, having 32~34 somites, were from 2.71 to 3.35mm in total length. The larvae absorbed the yolk material and oil globule completely in 7 days after hatching and became postlarvae. Nine days after hatching, the larvae averaged 5.35mm in TL and the caudal notochord flex at $45^{\circ}$ Total lengths of the larvae reached 6.00 and 6.58mm in 11 and 13 days after the hatching, respectively.

• Journal of the korean academy of Pediatric Dentistry
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• v.29 no.4
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• pp.632-640
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• 2002

The objective of the study was to apply the vibration technique to reduce the viscosity of bonding adhesives and thereby compare the bond strength and resin penetration into dentinal tubules achieved with those gained using the conventional technique. Eighty-eight noncarious extracted human permanent molar teeth were sectioned to remove the coronal enamel and were embedded in 1-inch PVC pipe with acrylic resin. The occlusal surfaces were placed so that the tooth and the embedding medium were at the same level to form one flat surface, and the samples were subsequently polished with silicon carbide abrasive papers. The samples were randomly assigned to 4 groups(n=22). On Group 1 and 2, Single Bond(3M-ESPE, St. Paul, USA) was used, and on Group 3 and 4, One-Step(Bisco Inc., Schaumburg, USA) was used, and each was applied according to its manufacturer's instructions. For Group 2 and Group 4, vibration was applied with ultrasonic scaler for 10 seconds, and the adhesive was light-cured for 10 seconds. Resin composite was condensed on to the prepared surface in two increments using a mold kit(Ultradent Products Inc., USA) and each was light-cured for 40 seconds. After 24 hours in tap water at room temperature the specimens were thermocycled, and shear bond strengths were measured with a universal testing machine(Instron 4465, Canton, USA). To investigate infiltration patterns of the adhesive materials, the surface of specimen was examined with scanning electron microscope. The results were as follows. 1. The shear bond strengths of vibration groups(Group 2, Group 4) were significantly greater than those of the non-vibration groups(Group 1, Group 3)(p<0.05). 2. The shear bond strengths of Single Bond and One-Step were not significantly different (p>0.05). 3. The vibration groups showed greater number of resin tags in tubules and lateral branches under SEM.