• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.36 no.2
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• pp.117-125
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• 2000

The waveform and spectrum analysis of Tursiops truncatus(bottlenose dolphin) sonar signals were carried out on the basis of data collected during the dolphin show at the aquarium of Cheju Pacificland from October 1998 to February 1999. When greeting to audience, the pulse width, peak frequency and spectrum level from the five dolphins'sonar signals were 3.0ms, 4.54kHz and 125.6dB, respectively. At the time of warm-up just before the show, their figures were 5.0㎳, 5.24kHz and 127.0dB, respectively. During the performance of dolphins, with singing, peak frequency ranged 3.28∼5.78kHz and spectrum level ranged 137.0∼142.0dB. With playing ring, pulse width, peak frequency and spectrum level were 7.0㎳, 2.54kHz and 135.9dB, and when playing the ball, the values were 9.0㎳, 2.78kHz and 135.2dB, respectively. The values determined from the five dolphins during jump-up out of water were : pulse width 2.0㎳, peak frequency 4.50kHz and spectrum level 126.8dB. When they responded to trainer's instructions, the values were 2.25㎳, 248kHz and 148.7dB, respectively, and greeting to audience, the peak frequency and spectrum level were 5.84kHz and 122.5dB. During swimming under water, peak frequency and spectrum level were determined to be 10.10kHz and 126.8dB. It was found that there exited close consistencies in pulse width, frequency distribution and spectrum level between whistle sounds and dolphin's sonar signals. Accordingly, the dolphins can be easily trained by using whistle sound based on the results obtained from the waveform and spectrum of the dolphin's sonar signals.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.36 no.3
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• pp.175-185
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• 2000

This paper described on a basic study to organize fishing vessel control system in order to control efficiently fishing vessel in Korean offshore. It was digitalized ARPA image on the fishing processing of a fleet of purse seiner in conducting fishing operation at Cheju offshore in Korea as a digital camera and then simulated by used VTMS. Futhermore, it was investigated on the application of FVTMS which can control efficiently fishing vessels in fishing ground. The results obtained were as follows ; (1) It was taken 16 minutes and 35 minutes to casting and hauling net in fishing processing respectively. The length of rope pulled by scout boat was 200m, tactical diameter in casting net was 340.8m, turning speed was 6kts as well. (2) The processing of casting and hauling net was moved to SW, NE as results of simulation when the current direction and speed set into NE, 2kts and SW, 2kts respectively. Such as these results suggest that can predict to control the fishing vessel previously with information of fishing ground, fishery and ship's maneuvering, etc. (3) The control range of VTMS radar used in simulation was about 16 miles. Although converting from a radar of the control vessel to another one, it was continuously acquired for the vector and the target data. The optimum control position could be determined by measuring and analyzing to distance and direction between the control vessel and the fleet of fishing vessel. (4) The FVTMS(fishing vessel traffic management services) model was suggested that fishing vessels received fishing conditions and safety navigation information can operate safely and efficiently.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.2
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• pp.183-194
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• 1995

The purpose of this study was to investigate the effect of vitamin E on the synthesis of the metallothionein in the liver of streptozotocin (STZ)-induced diabetic rats. Sprague-Dawley male rats($220{\pm}10mg$) were randomly assigned to one control and three STZ-diabetic groups. Diabetic groups were classified to STZ-0E(vitamine E free diet), STZ-40E(40mg vitamin E/kg of diet) and STZ-400E(400mg vitamin E/kg of diet) according to the level of vitamin E supplementation. Blood glucose levels of STZ-diabetic rats were three times higher than that of control. The contents of vitamin E in liver were lower signifciantly STZ-0E, STZ-40E groups by 50%, 36% compared with that of control. Lipid peroxide values(LPO) in liver were higher 5.6 and 2.5 times in STZ-0E and STZ-40E groups than that of control. Plasma cortisol levels were higher STZ-0E and STZ-40E groups compared with those of control, but cortisol levels were lower significantly in STZ-400E group compared with those of the STZ-0E and the STZ-40E groups. The plasma insulin levels were lower in all three STZ-diabetic group compared with that of control, but were not affected by the level of dietary vitamin E. The metallothionein (MT) contents in liver, kidney and small intestine were five times higher in STZ-0E, STZ-40E and STZ-400E compared with that of control, but STZ-400E group was lower in the MT contents in tissues compared with that of STZ-40E group. Zn-MT peak in STZ-diabetic rats liver increased than that of control by Sephadex G-75, and Zn-MT peak divided into MTI and MTII peaks by DEAE Sephadex A-25 column chromatography. The present results indicate that STZ-induced diabetic rats are more sensitive to oxidative stress, leading to the acceleration of lipid peroxidation process, which can be more promoted low level of dietary vitamin E. And the result may that increase synthesis of MT induced in the liver of diabetic rats increased so it can be sure that the diabetes is one of the MT induce factor by free radical generation. And high vitamin E supplementation reduced total MT contents of liver, kidney and small intestine and the peak of purified Zn-MT. Through the results of these experiments, we can conclude that MT might be the free radical scavenger.