• The Korean Journal of Malacology
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• v.30 no.3
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• pp.219-226
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• 2014

The effects of different stocking densities on the growth and survival rate of the abalone, Haliotis discus hannai, were investigated in marine net cage for two years. Stocking density was set 15, 30, 45 and 60 percentage $(=per.)/m^2$ with share to cross-sectional area per shelter. The primary rearing period (PRP) and the secondary rearing period (SRP) were conducted by a year. One year mean water temperature of PRP and SRS showed the difference about $2^{\circ}C$. In the growth (initial mean shell length of abalone : $36.14{\pm}2.28mm$) of PRP, the absolute growth rate (ARG), daily growth rate (DGR) and specific growth rate (SGR) of the $15per./m^2$ were higher than those of density groups (P < 0.05). Survival rates of all density groups were showed no significant difference. In the growth (mean shell length of abalone : $55.26{\pm}6.93mm$) of SRP, ARG, DGR and SGR of stocking density groups showed no significant difference except for $45per./m^2$ density group. Survival rate in the low-density (15, $30per./m^2$) was more than 70%, and those of the high-density (45, $60per./m^2$) were less than 31% and 9%, respectively. These results showed that the appropriate stocking density for $15per./m^2$ was seven hundred fifty number per one net cage ($2.4{\times}2.4m$), during PRP using 3-4 cm abalone in length. Also for the secondary rearing period, the optimal stocking density (shell length 5-6 cm of abalone) consider with the economical efficiency was determined to be $30per./m^2$, resulting the productivity improved.

• Korean journal of applied entomology
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• v.44 no.4 s.141
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• pp.293-298
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• 2005

The embryonic and postembryonic developments of Pierodorus hybneri Linnaeus were observed in 5 different rearing cages such as A (Cylindrical, 10 cm in diameter, height of 4 cm), B (Cylindrical, 14.5 cm in diameter, height of 2.8 cm), C (Rectangle, 6.5 by 6.5 cm in $length{\times}breadth$, height of 10 cm), D (Cylindrical, 9 cm in bottom diameter, 11.5 cm in upper diameter, height of 10.8 cm) and E (Cylindrical, 15 cm in diameter, height of 7.5 cm) containing soybean and peanut seeds as feeding food, and sponge-water container under laboratory condition of $24^{\circ}C$ and 16L:8D. Egg duration was 6 days regardless of rearing cages. Hatchability ranged from 63 to 80% with the highest in B (14.5 cm in diameter, 2.8 cm in height) rearing cage. Instar duration was longer from 5 days in 1st instar to about 11 days in 5th instar. Nymphal duration showed 35 to 36 days with'3ut significant difference in rearing cages. Percent emergence was in range from 65 to 82% with the highest in B rearing cage. Adult longevity was 35 to 83 days for male, and 32 to 79 days for female, and was the longest in B rearing cage. Total number of eggs laid by female adult was in range from 38 to 86 with significant difference in rearing cages, and was the most in B rearing cage. Accordingly, the reproductive rate of P. hybneri for 1 generation was within 17 to 56 times, and was the highest in B rearing cage. Therefore, it could be concluded that B cage is most suitable for stable rearing of P. hybneri under laboratory condition.

• Journal of Aquaculture
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• v.15 no.3
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• pp.145-155
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• 2002

Effect of density (30, 40, 65, 90 or 120/cage) of lantern and bottom cages on growth of the ark shell, Scapharca satowi was studied in the Korean west coast from April 2000 to October 2001, when the following range of environmental conditions prevailed : temperature : 4.2 -25.5 $^{\circ}C, salinity : 30.23-32.$15\textperthousand, dissolved oxygen : 5.12-7.16 $ml$/l, pH : 7.84-8.17, phosphate : 0.22-0.56 $\mu $M, dissolved inorganic nitrogen : 3.16-9.10 $\mu $M, suspended solid : 7.6-17.9 mg/l, chemical oxygen demand: 0.46-1.61 mg/l and chlorophyll-a : 0.92-5.93 $\mug/l. Daily growth rate of shell length ranged from 0.066 to 0.071 mm/day for the lantern net cages, and from 0.079 to 0.082 mm/day for the bottom cages. Total weight also ranged from 0.067 to 0.082 g/day in the lantern net cages, as against 0.099 to 0.114 g/day in the bottom cages. Hemoglobin content of S. satowi (55 mm shell length), which was about 3.9 g/dl during february, 2001, increased to 6.0 and 7.0 g/dl during October, 2001 in animals culture in the lantern and bottom cages, respectively. ANOVA test of the growth rate showed that the growth rate of S. satowi, was significantly dependent on rearing density and the tested culture methods (P < 0.0001). The daily growth rate of the shell length was more significantly correlated with water temperature; the growth rate of shell length and total weight showed a tendency decrease with decreasing temperature. In cages suspended at the bottom, not only the increase shell weight but also the meat obtainable from comparable sized S. satowi was greater. Survival decreased with increasing density and was optimal at the density of 30 individual/cage.

• The Korean Journal of Malacology
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• v.31 no.2
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• pp.93-101
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• 2015

The effects of different stocking densities on the growth and survival rate of the 3-year-old pacific abalone, Haliotis dicus hannai were investigated in marine net cage for a year. Stocking densities in net cage ($2.4{\times}1.2m$) was set 15, 30, 45 and 60 percentage (= per)/sq m (square meter, $m^2$) with share to cross-sectional area per shelter. The water temperature during the testing period was $8.2^{\circ}C-22.1^{\circ}C$, and salinity is $33.5{\pm}0.6psu$, and dissolved oxygen is $7.87{\pm}0.86mg/L$. In the shell length (initial size : $71.50{\pm}2.28mm$) growth and shell breadth (initial size : $46.43{\pm}2.28mm$) of the test abalones, the absolute growth rate (ARG), daily growth rate (DGR) and specific growth rates (SGR) of the 15 per/sq m and 30 per/sq m were higher than those of 45 per/sq m and 60 per/sq m density group (P < 0.05). Also in the weight (initial weight : $35.7{\pm}8.1g$), it showed the same results. In survival rates, it were that 15 per/sq m and 30 per/sq m is significantly higher than 45 per/sq m and 60 per/sq m. Therefore, it was that the 15 per/sq m is optimized stocking density in marine net cages about the 3-year-old pacific abalone over 70 mm size. The result shown that total cross-sectional area under the shelter is based on 15 per/sq m ($2.4{\times}2.4m$, 354 number in a net cage) is suitable for fast growth and survival. But if the economy consider, optimized stocking density would be appropriate to accept 30 per/sq m ($2.4{\times}2.4m$, 710 number in a net cage).

• Journal of Korean Society of Forest Science
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• v.100 no.3
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• pp.352-358
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• 2011

Field Cage plots ($1m{\times}1m{\times}1m$) were established (7 units) to find the lowest limit time about the tending of red pine forest (Pinus densiflora) which can no longer be used as a habitat by Monochamus alternatus, vector insect of pine wilt disease at the experimental forest of the southern forest research center of the Korea forest research institute in February in 2010. Thinning slashes (length, 1 m; diameter, 5~10 cm) tended at the different times were put in cages, and 4~6 couples of adult M. alternatus were put into each the cage in June. Presence or absence the larval entrance holes and larval were determined in November in 2010. Incase of the combination 24, 18, 12 and 6-month-old thinning slashes from thinning times to the time of adult emergence inside a single cage, larval entrance holes were found in the 6-month-old and 12-month-old thinning slashes but larvae were found only in the 6-month-old thinning slashes (treatment 1). In case of the combination 24, 18, 15 and 12-month-old thinning slashes inside a single cage, larval entrance holes were found in the 15-month-old and 12-month-old thinning slashes but larvae were found only in the 12-month-old (treatment 2). When 24, 18, 15, 12 and 6-month-old thinning slashes with treated dry and humid condition were put separately inside each cage, larval entrance holes were found in the 18, 15, 12, 6-month-old thinning slashes without the relation of the dry and humid conditions. But larvae were found in the 15, 12, 6-month-old thinning slashes in the dry conditions and only in the 6-month-old thinning slashes in the humid conditions. Results indicated the lowest limit time which can no longer be used as a habitat by M. alternatus is before 24 month from the time of adult emergence.

• Proceedings of the Acoustical Society of Korea Conference
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• spring
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• pp.233-236
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• 2000

The acoustical response of fish depends on size and physical structure na, most important, on the presence or absence of a swimbladder. Acoustic scattering models for swimbladdered fish represent a fish by an ideal pressure-release surface having the size and shape as the swimbladder. Target strength experiments of red seabream (Chrysophrys major) have been conducted using 38 (split-beam), 120 (split-beam) and 200kHz (dual-beam) frequencies. At each start of each experiment, the live fish are placed in the cage at the surface, then the cage is lowed to about $4{\cal}m$ depth where it remains during the measurements. To test the acoustic models, predictions of target strength based on swimbladder morphometries of 10 red seabream offish total length from $103{\cal}mm{\;}to{\;}349{\cal}mm$ ($3 <$TL/\lambda$ < 45)are compared with conventional target strength measurements on the same, shock-frozen immediately after caged experiments. X-ray was projected along dorsal aspect to know the morphological construction of swimbladder. and fish body. At high frequencies, Helmholtz-kirchhoff(HK) approximation would greatly enhance swimbladdered fish modeling. Sound scattering model [HK-ray approximation model] for comparison to experimental target strength data was used to model backscatter measurements from individual fish. The scattering data can be used in the inverse method along with multiple frequency sonar systems to investigate the adequacy of classification and identification of fish

• Journal of Marine Life Science
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• v.7 no.2
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• pp.163-170
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• 2022

In this study, the results of hybridization were evaluated by analyzing the biomarkers of Haliotis discus hannai and hybrid abalone (H. madaka♀^*H. discus discus♂) in marine net cage. The survival rate was similar both experimental groups, but the growth (shell length) was about 10% faster in hybrid abalone. The deformity of respiratory pore in the hybrid abalone was about 6% lower than H. discus hannai, and the shell depression was about 15% lower in the hybrid abalone. In the biochemical composition, crude protein was about 3.1% higher in hybrid abalone, and showed similar values except for the crude protein. In the histological structure of the hepatopancreas, which performs the functions of digestion, absorption and detoxification of abalone, good results were obtained in the hybrid abalone. On these results, it is judged that the hybrid abalone will have high aquaculture productivity in the aquaculture environment.

• The Journal of the Acoustical Society of Korea
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• v.10 no.3
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• pp.72-82
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• 1991

The Magnetic noise generated in three phase induction motor are investigated. Total noises measured by using JEM-1313 code and sound length method and the experimental formulae are derived of magnetic fk={K+$\frac{Z_s}{P}$(1-S)}f[Hz] noise is measured in the stator of induction motor except rotor supplied from power source and their datum are analyzed and compared with one another. The experimental value of magnetic noises are equal to the theoretical value at 1440[Hz] and 1560[Hz]. The biggest magnetic harmonic is generated at 1560[Hz].

• Journal of Chest Surgery
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• v.35 no.12
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• pp.882-889
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• 2002

Acute Complications of Remodelling Plasty of Costochondral Rib Cage For Pectus excavatum Recently, Remodelling Plasty of Costochondral Rib Cage has been introduced as an minimally invasive procedure and expanded its application for pectus excavatum. Outcomes and acute complications were reviewed Material and Method: A retrospective survey of 55 patients who underwent Remodelling Plasty of Costochondral Rib Cage from September, 1999 to February, 2002 was conducted to review complications, postoperative treatments, and outcomes. Result: Age ranged from 1 to 27 years(mean 11.4 $\pm$ 7.1). 35(64%) were less than 15-year old and 20(36%) were more than 15-year old. There were 44(80%) Male patients and 11(20%) female patients. Length of hospital stay was 7.8 $\pm$ 2.1 days for less than 15-Y-old group, 10.6 $\pm$ 6.2 days for more than 15-Y-old group(p ＝ 0.042) One substernal bar was inserted in 52 patients and two substernal bars were inserted in 3 patients. As for stabilizer, one lateral side was fastened in 15 patients and both lateral sides were fastened in 6 patients. In the less than 15-Y-old group, 4 patients needed stabilizer, whereas in the more than 15-Y-old group, 18 patients needed stebilizer(s)(p ＝ 0.000). Including all kinds of complications, 28(51 %)patients had postoperative complications. Of them, only 7 patients were treated for complications(C-tube insertion was done in 7 patients and reoperation for bar refixation or removal was done in 3 patients of them). Conclusion: Most complications after Remodelling Plasty of Costochondral Rib Cage For Pectus Excavatum were trivial without treatment although C-tube drainage was needed in some patients. However bar displacement such as rotation and lateral sliding should be corrected as soon as detected in order not to remove the bar(the worst situation).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.4 no.3_4
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• pp.113-120
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• 1971

In 1971, about 150,000 fingerlings of grass and silver carps were produced and distributed from the Fishculture Laboratory of Pusan fisheries College. The adults Were those transplanted from Japan in 1963. Findings during the process of this production are summarized as following : 1. Brood fish must be handled with a great care during the catching, hormone injection and maturity inspection so as the fish are not injured, otherwise, the eggs would not mature perfectly. Scale fall also affects significantly. 2. The amount of pituitary to be injected is preferable to be 2 to 3 times or more in donor's body weight to obtain good results. 3. The eggs should be spawned or stripped and inseminated as soon as mature. If the spawning is delayed the eggs become overmature and the hatching rate decreases significantly. 4. The water once used for the incubation of eggs should not be reused. The eggs under hatching process were melted away when water once used for incubation was reused. 5. A great care must be paid to keep water in quality when the net cage culture system is employed for raising fry or early fingerlings of Chinese carps. The best method to keep water in quality is to supply water in the cage continuously through a pipe or hose. 6. Heavy outbreaks of Spirogyra occured when clear well water was supplied into the cage, and a great number of fry or fingerlings were trapped or entangled resulting in a significant decrease of fish under rearing. It was prevented when moderately bloom-ed pond water was supplied into the cage. 7. Silver carp fry are usually captured and transported in the cool season because they can not be handled in the warm season owing to a high mortality, but cage cultured small size fingerlings ranging from 1.5 to 2 cm in total length are easily handled and transported even in the hot summer season, thus it enables the fish farmers to start growing them one season earlier.