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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 32, Issue 4 - Dec 1996
Volume 32, Issue 3 - Sep 1996
Volume 32, Issue 2 - Jun 1996
Volume 32, Issue 1 - Mar 1996
Selecting the target year
Behavioural Characteristics of Walleye Pollack Theragra chalcogramma by Acoustic Sound Conditioning
Journal of the Korean society of Fisheries Technology , volume 32, issue 4, 1996, Pages 331~339
It is most important to understand the behaviour of fish in case of the betterment of the current fishing gear and methods or the development of the conditioning by acoustic sound in marine ranching. This investigation has been attempted to provide for the prediction of the response action of fish to acoustic sound. The experimental fish was conditioned with sound and bait. As the acoustic sound for stimulus, the pure tone of sine waveform at the frequency of 200Hz was used. This pure tone was determined from previous investigation about hearing ability of walleye pollock Theragra chalcogramma. The fork length of walleye pollock used in this experiment was 385~450mm. The conditioning proceeding was recorded in the video tape recorder. Frequency of appearance in the feeding area was analyzed with computer and video tape recorder. The position of fish was tracked using the mouse cursor and picture mixed on the superimpose board. The response of conditioned fish to sound stimulus was appeared in the 8th day firstly. The conditioned fish remembered the stimulus sound for 4 days. Average frequency of appearance in the feeding area during the 30 seconds sound projection or 1 minute after the sound stimulus was 51%, and was higher than before it.
A Study of Fishing Ground Distribution in Korean Tuna Long-Line , Using the Catch Data Base System
Journal of the Korean society of Fisheries Technology , volume 32, issue 4, 1996, Pages 340~355
In order to suggest the useful information of fishing ground, a data base system on 32bit personal computer was constructed and handled by using the catch data of Korean tuna long-line, catch by species, fishing time and place, fish price and etc. mainly from 1975 to 1992. The results obtained are as follows ; In the fishing ground displaying catch rate, the catch rate has reduced as time passed, and this penomenon was more evident in Indian. And yellowfin have high catch tate in the Western Pacific of low latitute region, bigeye tuna have in the Eastern. The region of high catch rate of bigeye tuna was moved from the Indian and the Atlantic to the Pacific. The patterns of catch numbers of yellowfin and bigeye tuna appeared nearly same that, having nothing to do with catch numbers in all oceans. The region of least catch was the Northwestern Pacific, the regions of most catch were the Western Indian and the Pacific of low latitute. As to simulation of fishing ground estimation, there were economical grounds in the Western Pacific of low latitute region, the Eastern Pacific of this, the Western Indian, the Eastern Indian, and the Atlantic, in order.
The Development of Data Base Program on the Catch of Long-Iine Tuna
Journal of the Korean society of Fisheries Technology , volume 32, issue 4, 1996, Pages 356~362
In order to suggest the useful information of fishing ground, a data base system on 32bit personal computer was developed and handled by using the catch data of Korean tuna long -line. This data base system was programmed using Quick Basic, and consisted of three kinds of programs, one for displaying the catch rate on the fishing ground by fishing area and year ranges, another for indicating the catch rate or number on table or graph, and the other for estimating the fishing ground in economical points, mainly targeting total tunas, yellowfin and bigeye tuna respectively. When this system was started, the map of oceans such as the Pacific, the Indian and the Atlantic, is drawn on the monitor. And then the catch rates of all species and each one are indicated by the figured symbols on the sea divisions of
space of latitute and longitude.
The Relative Distance in Taking Action for Collision Avoidance Maneuver of the Stand-on Vessel
Journal of the Korean society of Fisheries Technology , volume 32, issue 4, 1996, Pages 363~371
The Steering and Sailing Rules of International Regulations for Preventing Collisions at Sea now in use direct the best aid - action to avoid collision by the stand - on vessel. But these rules do not refer to the safety relative distance between two vessels when she should take such action. In this paper, the author analyzed the ship's collision avoiding actions from the viewpoint of ship motions and worked out mathematical formulas to calculate the relative distances necessary for taking action to avoid collision. Figuring out the values of maneuvering indices through experiments of 11 actual ships of small, medium, large and mammoth size, the author applied these values to the calculating formulas and calculated the minimum relative distances. The main results are as follows: 1. It was confIrmed that the stand - on vessel should keep the greatest relative distance for taking best aid - action to avoid collision when the cross angle of course was
and near it(70-
). 2. When the cross angle of course was
, the minimum relative distance of small vessel(GT: 160-650tons) was found to be more than about 6.8 times of her own length, and those of medium(GT : 2,300-3,500tons), large(GT : 22,OOO-62,OOOtons) and mammoth(GT : 91,000-139,000tons) vessels were found to be more than about 9.0 times, about 5.4 times and about 6.8 times of their own lengths. 3. It was confIrmed that collision danger was greater when crossing angle was obtuse than in an acute angle, therefore greater relative distance was to be kept by the stand - on vessel for taking best aid - action to avoid collision in the case of the obtuse angle. 4. In every vessels, in the case of
cross angle of course the safety minimum relative distance was found to be more than about 9.0 times of their own lengths.
A Study on the Accuracy of the Loran-C Fix of Korean Chain in Pusan Area
Journal of the Korean society of Fisheries Technology , volume 32, issue 4, 1996, Pages 372~380
The operation of Far East Chain(GRI 5970) of Loran - C system had been stopped on June, 1995, but that of Korean Chain(GRI 9930) of Loran - C system which was jointed with North West Pacific Chain(GRI 8930) and Russia Chain(GRI 7950) by international cooperation, was started on January 1996. In this paper, in order to study the accuracy of Loran - C fix of Korean Chain, the authors examined and analyzed the data of the reciever of Loran - C(LC -90, Furuno) and GPS(AccNav Sport super (TM), Eagle) measured automatically and continually for 2 seconds at interval of 5 minutes from November 22, 1992, to January 20, 1996 at the fixed position of National Fisheries University of Pusan, The results obtained were as follows ; 1)The mean time differences of M-W, M-X, and M-Y pair measured in the base observed position were 12333.09
s, and 42806.01
s respectively and the mean standard deviations of that were 0.0121
s, and 0.0327
s respectively. The daily and monthly variance forms of time difference at each pair appeared in a similar reappearance. 2)The mean standard deviations of the latitude and longitude by Loran - C were 9.1m and 17.4m in W.X pair, 11.5m and 13.7m in W.Y pair, and 8.1m and 29.3m in X.Y pair respectively, and then the probable radiuses within 95% of each pair were 39.2m, 35.7m, and 60.8m, respectively. Therefore, It is to be desired that W.Y par is selected to improve the accuracy in Pusan area. 3)The mean standard deviations of the latitude and longitude by GPS were 15.4m and 15.0m and the probable radius within 95% was 43.4m. 4)The position errors for GPS and each pair of Loran - C were 16.0m to the South in GPS and 265.2m to the East in W.X pair of Loran - C, 279.5m to the North in W.Y pair of that, and 224.3m to the North-West in X.Y pair of that, so GPS is about 250m higher than Loran - C in accuracy.
Characteristics of Underwater Air-Bubble Curtain Generating by the Compressed Air
Journal of the Korean society of Fisheries Technology , volume 32, issue 4, 1996, Pages 381~385
This paper described to experiment and analyze for the characteristic of underwater airbubble curtain which was generated by the air - bubble curtain generating unit consisted with air compressor (290l/min x 1.5Kw) and air tank(10kgf/
) in order to provide foundation source for guiding fish schools. To layout the air - bubble curtain was made vinyl hoses(
emitting air - pressure, the wider hole interval of hose drilled the higher air - bubble curtain could be formed, and then the horizontal length of air - bubble curtain could be prolonged 45% according to be inclined vertical angle of air - bubble generating hose.
The Transparency Variation According to Tidal and Seasonal Variation in Deukryang Bay , 1995 and 1996
Lee, Byung-Gul ; Cho, Kyu-Dae ; Choi, Yong-Kyu ;
Journal of the Korean society of Fisheries Technology , volume 32, issue 4, 1996, Pages 386~394
The temporal variations of the transparency with water temperature, salinity and density during spring-neap tidal cycle of spring, summer, autumn and winter time were investigated at 34 stations using observation data in Deukryang Bay, Korea, in 1995. It was found that the transparency was depended on spread of tidal currents and vertical stratification of water. The depth of transparency during neap tide was deeper than that of spring tide. The value of transparency in summer was the largest among four seasons. We concluded that the vertical stratification intensity of water mass and vertical distribution of transparency.
A Basic Study for the Propagation Characteristics Due to the Horizontal Water Temperature Variations in the Sea
Ha, Kang-Lyeol ; Kim, Moo-Joon ;
Journal of the Korean society of Fisheries Technology , volume 32, issue 4, 1996, Pages 395~401
In this paper, the propagation characteristics due to the horizontal water temperature variations in the sea such as thermal fronts is analyzed by the ray theory. Two models for the temperature anomaly layer are chosen. One is a plane type and the other is a cylindrical type. In the plane type, the temperature increases linearly from a isothermal region to 5km with the gradient of about
/km, and decreases with the same gradient in next 5km. In the cylindrical type, water temperature increases only with the same gradient from a half cylindrical thermal boundary surface. The result showed that the gradient of acoustic rays decreases in the temperature increasing region and vice versa in temperature decreasing region. And, the transmission loss due to the temperature variation was less than O.2dB in the plane type model as well as in the cylindrical one.
Fracture Behavior for Carbon Fiber Reinforced Plastic by Immersion
Kim, O. G. ; Nam, K. W. ; Ahn, B. H. ;
Journal of the Korean society of Fisheries Technology , volume 32, issue 4, 1996, Pages 402~410
Recently carbon fiber reinforced plastic(CFRP) has been used structural materials in corrosive environment such as for water, chemical tank and chemical pipes. However, mechanical properties of such materials may change when CFRP are exposed to corrosive environment for long periods of time. Therefore, it is important to understand the effect of moisture absorption on mechanical properties of the CFRP. In this study, degradation behavior of immersed carbon fiber/epoxy resin composite material was investigated using acoustic emission(AE) technique. Fracture toughness test are performed on the compact tension(CT) test specimens that are pilled by two types of laminates
During the fracture toughness test, AE test was carried out to monitor the damage of CFRP by moisture absorption. In spite of the change of moisture absorption rate, the fracture toughness of CFRP was not change. As immersion time increased, AE event count numbers decreased in low amplitude range of AE for amplitude distribution histogram. The event in low amplitude range was known to be generated by debonding of matrix-fiber interface. Therefore, decrease of AE event count numbers in low amplitude range represents that debonding of matrix-fiber interface which was probably generated by moisture absorption.
A Study of Thermodynamical Reaction Path in Fe-Cr-X Alloys at High Temperature Corrosion Environments
Lee, Byung-Woo ; Kim, Woo-Yeol ;
Journal of the Korean society of Fisheries Technology , volume 32, issue 4, 1996, Pages 411~420
The structure of the scale formed on the surface of Fe - Cr - X alloys exposed to 1143K high sulfidation(
atm) or sulfidation/oxidation((
atm) environment has been observed and analysed using XRD, SEM/EDS. To investigate the possibility of protective film formed on the surface of the alloys, Aluminium, Nickel were selected as alloying elements. Thermodynamic phase stability diagram was used to predict the reaction path of scale formed on Fe - Cr - X alloys. Parabolic rate constant(
) value with 6wt% Al in Fe - 25Cr alloy decreased significantly compared with the Fe - 25Cr alloy without 6wt% Al. Since thin layer of defect free sulfide film, (Al, Cr)Sx, was formed at the alloy/scale interface. Fe - rich sulfide scale at outer layer and Cr - rich sulfide scale containing porosity at inner layer of Fe - 25Cr alloy have been observed. The reaction path for these scales could be predicted by the thermodynamic stability diagram.
Study on the Characteristics and Development of Impact Dynamic Vibration Absorber
Kim, Won-Cheol ; Lee, So-Hwan ; Yang, Bo-Seok ;
Journal of the Korean society of Fisheries Technology , volume 32, issue 4, 1996, Pages 421~431
From comparing the impact dynamic absorber with the impact damper in the auxiliary vibration system with the conventional dynamic absorber, the following conclusions are obtained as follows ; 1. Recognizing that the amplitude restraining effect of the impact dynamic absorber become resonable in a comparison of conventional one development of an improved dynamic absorber may be probable. 2. With increasing the frequency ratio, the 1st resonance peak is higher but the 2nd one gets lower. In addition, the frequency ratio is peak located at the same resonance. 3. The optimum impact clearance is smaller and the vibration constraining effect becomes better with and increase in the mass of impact ball. And it is recognizable that the optimum tuning frequency ratio and impact clearance in an accordance with the mass ratio are varied. 4. The optimum tuning condition becomes gradually lower than the case of r=1 and maximum amplitude becomes lower with an increment in the mass ratio. However, the impulse clearance is larger and the working range of restraining vibration amplitude become smaller with a decrement in the mass of impact ball.
A Study on the Stochastic Finite Element Method Based on Variational Approach
Bae, Dong-Myung ; Kim, Kyung-Yull ;
Journal of the Korean society of Fisheries Technology , volume 32, issue 4, 1996, Pages 432~446
A stochastic Hamilton variational principle(SHVP) is formulated for dynamic problems of linear continuum. The SHVP allows incorporation of probabilistic distributions into the finite element analysis. The formulation is simplified by transformation of correlated random variables to a set of uncorrelated random variables through a standard eigenproblem. A procedure based on the Fourier analysis and synthesis is presented for eliminating secularities from the perturbation approach. In addition to, a method to analyse stochastic design sensitivity for structural dynamics is present. A combination of the adjoint variable approach and the second order perturbation method is used in the finite element codes. An alternative form of the constraint functional that holds for all times is introduced to consider the time response of dynamic sensitivity. The algorithms developed can readily be adapted to existing deterministic finite element codes. The numerical results for stochastic analysis by proceeding approach of cantilever, 2D-frame and 3D-frame illustrates in this paper.
Design and Implementation of a CAI System for Testing the Ability of Ship Engineers ( 1 )
Journal of the Korean society of Fisheries Technology , volume 32, issue 4, 1996, Pages 447~456
A Study on the Vibration Damping of Multilayer Damping Sheet
Kim, Won-Ho ; An, Byeong-Hyeon ; Ahn, ;
Journal of the Korean society of Fisheries Technology , volume 32, issue 4, 1996, Pages 457~464
The vibration damping of various multilayer damping sheet with different constraining layer and viscoelastic layer were investigated by Rheovibron and vibration test. Damping increased as dynamic loss tangent increased. Constrained type damping sheet showed better damping than extensional type damping sheet. Aluminum foil attached asphalt impregnated paper pad showed best damping.