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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of the Korean society of Fisheries Technology
Journal Basic Information
Journal DOI :
The Korean Society of Fisheries Technology
Editor in Chief :
Volume & Issues
Volume 33, Issue 4 - Dec 1997
Volume 33, Issue 3 - Sep 1997
Volume 33, Issue 2 - Jun 1997
Volume 33, Issue 1 - Mar 1997
Selecting the target year
A Study on the Hull-dimension of 89 ton class Stow-net Vessel with Stern-fishing
Park, Je-Ung ; Lee, Hyeon-Sang ;
Journal of the Korean society of Fisheries Technology , volume 33, issue 3, 1997, Pages 159~165
This paper presents the optimum dimension of 89 ton class stow-net vessel with stern-fishing. The model of basic design is developed by using the optimization techniques referring to objective function and numerous constraints as follows; speed, fishing quantity, fishing days, catch per unit effort(CPUE), and weight/ratio of main dimensions, etc. Thus, the basic design of stow-net fishing vessel is built up by using the optimization of the design variables called the economic optimization criteria, and the objective function represents the criterion which is cost benefit ratio(CBR). The main conclusions are as follows. 1. S/W for decision of optimum hull size is developed in 89 ton class stow-net fishing vessel which is constructed with optimization of the design variables called the economic optimization criteria. 2. For optimum ship dimensions in 89 ton class stow-net fishing vessel, the hull dimensions can be obtained in the range of L= 27.3m, B = 6.6m, D = 2.80m, Cb = 0.695, T/D = 0.80,
(displacement)=281.7ton with 10 knots.
A Study on the Development of the Extermination gear for Starfish, Asterias amurensis and its Efficiency
Park, Seong-Uk ; Kim, Tae-Ho ; O, Hui-Guk ;
Journal of the Korean society of Fisheries Technology , volume 33, issue 3, 1997, Pages 166~172
In order to exterminate effectively starfish, Asterias amurensis inhabited a village fishing grounds and shellfish farms on coast of Korea, Mop and sledge gear were made and sea trials for capture efficiency of starfish by each gear and towing distance were carried out by commercial dredger on the coast of Keojedo from April to May in 1995. As Starfish mop and sledge were slowly dragged over the bottom at the same time, starfish became entangled in bunches of twine and netting respectively. The gears were hauled up at intervals to remove the starfish and hand-picking operations on vessel were conducted. The results obtained are as follows : Two gears were smoothly slidden over the sea bottom and captured numerous starfish. The optimal towing distance by each gear was 300 to 500 m.The capture efficiency of starfish species by sledge was 57% compared with 43% of that by mop but mixed rate with fish or shellfish of the former was 21 times as high as that of the letter. It was concluded from sea trials that moping was effective in shellfish farms, because the mop outfit causes little damage to useful shellfishes and the mixture of starfish with fish or shellfish was low, whereas sledging can be used to clean uncultivated areas free of shellfish where starfish population is very heavy and common fishing grounds in which bottom material is rock or gravel.
A Study on the Behaviour of Fish Schools in the Process of Catch of the Purse Seine Fishing Method
Park, Jeong-Sik ; Kim, Seok-Jong ; Kim, Sam-Gon ;
Journal of the Korean society of Fisheries Technology , volume 33, issue 3, 1997, Pages 173~182
This study is a basic research in purse seine fishery : on the behaviour of fish schools of tilapia Tilapia mossambica in the process of catch of the purse seine fishing method. The experiment was carried out for the mackerel purse seine which using of power block by fishing fleet system in the near sea of Cheju Island and as a forecast in the near future on the purse seine fishing, using of triplex net winch by one boat system in the near sea of Norway. These model purse seines were made of the scale of 1/180 of its full scale. The model purse seine test on the escaping behaviour of fish school by gap, area reducing of gap and tension of purse line was carried out in the stagnant water of experimental water tank. Designing and testing for the model purse seines were based on the Tauti's law. The results obtained were as follows : 1. When the time for the completing of pursing was 20 minutes, average swimming speed of fish school through a gap was 9.71cm/sec for powerblock seine and 9.97cm/sec for triplex seine. 2. In the case of pursing time in actual value was 20minutes, at 50 percent of the pursing, swimming behaviour of fish school in purse seine was 10% to I section, 80% to II section, 10% to III sectional direction for powerblock seine and a similar tendency for triplex seine. 3. In the case of pursing time in actual value was 20 minutes, at the time of 10 minutes have proceeded since then, area reducing rate of gap of the seine in projected front view was 63.5% for powerblock seine and 67.5% for triplex seine. 4. In the case of pursing time in actual value was 20 minutes, escaping rate of fish school by gap in projected front view was 70% for powerblock seine and 30% for triplex seine. Maximum tension of purse line was about 8.1 tons for powerblock seine and about 8.3 tons for triplex seine.
The Design of Broadband Ultrasonic Transducers for Fish Species Identification - Control of the Resonance Frequency of a Piezoelectric Transducer with Two Pair of Electodes -
Journal of the Korean society of Fisheries Technology , volume 33, issue 3, 1997, Pages 183~188
A method for designing a broadband transducer was investigated experimentally. Control of the resonance frequency of a Piezoelectric circular transducer with two pairs of electrodes was achieved by varying the inductance of external coil connected across the terminal of one pair of electrodes of transducer. The conductance curves of transducer in water were obtained as a function of the inductance value in mH of the coil used in the tuning. As the tuning inductance is increased in value, the resonance frequency is reduced toward the fundamental frequency of 50 kHz. This interesting result suggest that it is possible to produce a continuously tunable transducer covering a frequency range between 61.3 kHz and 121.7 kHz by varying the inductance value of external coil from 2.7 mH to 15.0 mH. One of other problems in the design and construction of such broadband transducer is the transducer efficiency, but this will be the subject of our future work.
Development of Trawl Monitoring System ( 1 ) - Distance Measuring System between Trawl Doors -
Shin, Hyeon-Ok ; Lee, Chun-Woo ;
Journal of the Korean society of Fisheries Technology , volume 33, issue 3, 1997, Pages 189~193
We make an ultrasonic system as a trial to measure the distance between trawl doors, and carried out a water tank (
m, water depth 1 m) experiment for confirming the practical use of the system in October 1996. This system calculates the distance between the pinger (50 kHz) and the transponder (50 kHz/70 kHz) attached each one on the trawl door by measuring the time-difference of receiving with two channels receiver on the trawler. This paper assums that both the length of the warp from the stern to the trawl door is same. At results the system shows a good relation between the distance and the time-difference of receiving while the location of the pinger is moved in variously in the water tank, and it was found that the method of measuring techniques on the prototype system could be applied to the measurement of the trawl door opening in the field experiment.
Study on the Stress Corrosion Cracking Behaviour of Piping for Industrial Water
Im, U-Jo ; Lee, Jin-Pyeong ;
Journal of the Korean society of Fisheries Technology , volume 33, issue 3, 1997, Pages 194~201
Recently with the rapid development in the industries such as an iron mill and chemical plants, these are enlarged by the use of the piping. This piping was encountered the stress corrosion cracking(SCC) because of stress by water pressure and residual stress of welding etc. under industrial water. In this paper, the behaviour of stress corrosion cracking on the weld zone of steel pipe piping water(SPPW) were investigated according to pre-heat before welding in natural seawater(specific resistance : 25
-cm). The main results obtained are as follows :1) The stress corrosion cracking for SPPW and SB 41 is most ready to propagate in heat affected zone of weldment. 2) The SCC sensitivity of SPPW on weldment is more susceptible than that of SB 41. 3) The stress corrosion cracking growth of heat affected zone is delayed by the preheat and dry of base metal and electrode before welding.
Study on the Charactistics of Cavitation Erosion-Corrosion for Mild Steel(3) - Behavior of Erosion-Corrosion Damage Suppression Under Vibration Cavitation-
Hwang, Jae-Ho ; Lim, Uh-Joh ; Jeong, Ki-Cheol ;
Journal of the Korean society of Fisheries Technology , volume 33, issue 3, 1997, Pages 202~208
The component materials threatened by cavitation include ship propellers as well as turbine runners, pump impellers, pipe lines and radiators. Today it is known that cavitation damage takes place on many other components including on the coding water side of the cylinder liners of diesel engines. Cavitation erosion - corrosion implies damage to materials due to the shock pressure or shock wave that results when bubbles form and collapse at a metal surface within a liquid. To suppress cavitation erosion as well as cavitation erosion - corrosion to hydraulic equipment, innovations such as the improvement in the geometric design of the equipment or the selection of suitably resistant construction materials are necessary. In this study, we investigated that the cavitation erosion - corrosion damage under vibratory cavitation can be reduced by adding of side now velocity to the cavitation bubble group in order to eliminate bubbles formed in sea water environment.
Improvement of Thermal Enviromental by Two Air Out in Hot Air Heating
Jang, In-Seong ; Kim, J.S ;
Journal of the Korean society of Fisheries Technology , volume 33, issue 3, 1997, Pages 209~217
The objective of this paper is to improve a discomfort caused by the unequal airflow and vertical temperature difference by buoyancy of the supplied hot air in the conventional hot air heating system. In order to the model experiment we manufactured the hot air heater with two air outlet and a model room. We observed the temperature, velocity and airflow distribution and calculated values of PMV and PPD using mean value of central verticality section's air temperature and velocity. We could improve distribution of vertical temperature and velocity at the central section of the model room owing to correlation of hot air of two air outlet.
Spectral Model of Turbulent Burning Velocity Taking Account of the Diffusivity of Deficient Reactant
Journal of the Korean society of Fisheries Technology , volume 33, issue 3, 1997, Pages 218~225
The formerly proposed spectral model of turbulent burning velocity is refined for nonstoichiometric hydrocarbon mixtures. Refinements are made in regard to the following two points : (1) an effect of the diffusivity of deficient reactant on the turbulent burning velocity and (2) consideration of increasing laminar name thickness with a decrease in the laminar burning velocity A comparison between the predicted turbulent velocities and the measured ones is made. The predictions by the refined spectral model agree quantatively well with the experimental results in the regime of practical equivalence ratio, but not in the high and low equivalence ratio regime.
Modelling Relative Water Flow and its Sensitivity of Fish in a Towed Fishing Gear
Journal of the Korean society of Fisheries Technology , volume 33, issue 3, 1997, Pages 226~233
A Study on the Estimating the Degree of Reaction for a Turbine Using a Synchronizable Turbocharging System
Journal of the Korean society of Fisheries Technology , volume 33, issue 3, 1997, Pages 234~240
A Study on the Improving Disel Performance by Means of Cyclic Synchronizing Power and the Geometrical Features of Turbocharging System
Journal of the Korean society of Fisheries Technology , volume 33, issue 3, 1997, Pages 241~247
Measurement of Dispersion Relation of Plasma Wave
Jeong, Jung-Hyeon ; Lee, Jong-Gyu ;
Journal of the Korean society of Fisheries Technology , volume 33, issue 3, 1997, Pages 248~258
The analytical solutions of the Fraunhofer Diffraction(FD) theory and the principle for measurement of the dispersion relation of plasma wave is presented. Especially, the method for measurement of low-frequency wave is discussed. The wavenumbers of the density fluctuations are obtained from the curve fitting between the expremental FD profile and theoretical one for each frequency component. In measurement of the wavenumber of the low -frequency region, the information of the wavenumber is easily obtained from the ratio of the intensity at = 0 to the intensity at =0.5. The millimeter wave FD apparatus was designed to measure low-frequency density fluctuations. The determined wavenumbers are in the range of =0.1~ 1.0cm. Thus, the millimeter wave FD method was shown to be useful for the measurement of low-frequency density fluctuations, which are impossible to be measured by using a convention. Thomson scattering. The obtained dispersion relations will be useful information for plasma waves.