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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 35, Issue 4 - Nov 1999
Volume 35, Issue 3 - Aug 1999
Volume 35, Issue 2 - May 1999
Volume 35, Issue 1 - Feb 1999
Selecting the target year
A Study on the Design of the Stern Stow Net
Journal of the Korean society of Fisheries Technology , volume 35, issue 4, 1999, Pages 343~352
Because stow net being used in now is doing throwing net and hauling net through a ship's side, the work is very complicated and the fishing boat needs many seamen and it could cause a loss of lives and ship in stormy weather. We are now using small mesh size 36~500mm and it even catches young fish, so we call it the fishing gear of resource reduction type.Therefore we must make manpower reduction in automatic operation, safe operation of throwing net and hauling net in the stern and the stern-typed stow net of resource management using large mesh. And we performed three-typed model tests to examine the fishing gear. The obtained results are as follows;1. The fishing gear being used in the ship's side type stow net has inappropriate standard and arrangement of the net, resistance increase of the fishing gear and frequent breakdown of the net.2. To supplement the fault of A-typed stow net, we schemed fishing gear developed as both B-type(12-seamed net) and C-types(8-seamed net) of the stern-typed stow net. 3. In model tests, C-typed model net(mesh size 40~1,600mm) was proved good fishing gear because the resistance in accordance with the flowing speed was comparatively small and it's mouth area was broad. 4. A-typed stow net had the spreading device attached to side panel of the net, but the stern-typed stow net had the spreading device consisted of 4 lines far behind about 6m from side panel of the net mouth. In the flowing speed 2knot, the spreading condition of fishing gear was proved batter than the former.
use of Cable Functions by Pode's Analysis in a Towing Cable or a Buoy Cable
Journal of the Korean society of Fisheries Technology , volume 35, issue 4, 1999, Pages 353~358
Tabulated results by Pode are used for computing the cable shape and cable tension in static equilibrium. This paper describes a technique using the integral form by Pode to give a simplified calculation of the cable functions at any desired value because in most practical cased the points of interest on the cable are not the points of reference on which the tables are based. Solving the nondimentional tension,
, defined by Pode in closed form reduces the integral in cable functions to a single integral. The technique using the integral form enables us to calculate the cable functionsin at any critical angle and at any point in case of a towing cable or certain cable-buoy systems.
A Study on the Growth and Environmental Development for the Protection-nourishment of Fisheries Resources 2. Marine Litter on the Sea-bed of Chinhae Bay
Journal of the Korean society of Fisheries Technology , volume 35, issue 4, 1999, Pages 359~365
This study deals with litter which has sunk and accumulated on the sea-bed of the Chinhae Bay obtained by using a beam trawler. The litter collected through the duration of survey (1997~1998) were distributed from 8.76~80.63 items/ha and 3.51~108.39 kg/ha, respectively, in quantities and weights. Especially bulky wastes(shell, tires, motorcycle and refrigerator) were composed of 76% of them, next metal and glasses, 29.5%. The seasonal variability of litters in the bay is large, as 62% in April, next August, 23%, in total weights.These discarded substances have the widespread distribution but varied in each sampled area. Therefore they exist in a significant pollutants, as threatening the fishing activities and near marine environment, and also potential damage to marine resources.
A Study on the Catching Selectivity of the Ark Shell(Scapharca Broughtonii)Dredge
Journal of the Korean society of Fisheries Technology , volume 35, issue 4, 1999, Pages 366~376
In order to examine the catching selectivity of the ark shell(Scapharca broughtonii) dredge, the various factors affecting the selective action of the dredge are analyzed, and the probabilities of the ark shell not shifting through the gaps between the teeth, and the mesh of the netting bag, are calculated for the various shell lengths, using the relation between the posture and the length when the shell passes through these parts.Considering that the probability of making catch is the product of the both probabilities described above, and that this probability is proportional to the relative catching efficiency, the selectivity curves for the ark shell dredge were estimated for various gaps between the teeth and for the various mesh sizes of the netting bag. The obtained results are summarized as follows :1. The ratios of the shell length of ark shell to the distance between teeth indicating the relative catching efficiency of 0%, 50, 100% respectively were 1.0, 1.26~1.28, 1.47~1.44, and that the selection ranges of selective shell length by the distance between teeth were 0.47~0.44, where the distances between teeth were 3.2cm, 3.6cm, 4.0cm, 4.4cm and 4.8cm. 2. The ratios of the shell length of ark shell to the mesh size indicating the relative catching efficiency of 0%, 50%, 100% respectively were 0.67, 0.84, 0.97 and that the selection range of shell length for catching, that in the range of selective shell length by the mesh size was 0.31, where the distance of 4.0cm between teeth, mesh size of 6.0 cm and the smaller mesh angle of
3. Where the distance between teeth is 4.0 cm and the smaller mesh angle is
, the selection range of shell length for catching of the ark shell dredge is decreased according to the mesh size, and it is minimized by 0.20 in the mesh size of 9.0~10.0 cm, but increased in the mesh size of over 11.0 cm. 4. Where the distance between teeth is 4.0 cm, the selective action by the mesh size of netting bag is begun with the mesh size of over 10.0 cm.
Distribution of Anchovy School Catched by the Lift Net and Environmental factors in the Kamak Bay 2. Relation between Distribution of Anchovy school and Chlorophyll-a
Journal of the Korean society of Fisheries Technology , volume 35, issue 4, 1999, Pages 377~385
In order to investigate the properties in distribution and movement of anchovy school catches by the lift net in the Kamak bay and their relation to the environmental factors, I. e., the amount of chlorophyll-a and turbidity were observed from June to August in 1997 and compared with the catch of anchovy by the lift net. The results obtained are summarized as follows;1) The amount of chlorophyll-a ranged from 4.0 to 12.0 mg/
on July and from 3.0 to 15.0 mg/
on August in horizontal distribution, the amount of chlorophyll-a ranged from 3.0 to 8.0mg/
on June, from 5.5 to 11.6 mg/㎥ on July, and from 6.0 to 11.1 mg/
on July and from 1.0 to 6.0ppm on August, respectively. 2) Anchovy school can be presurmed, they are come from north of bay, visited and distributed through east of bay at the middle of June. Moreover, they spreaded in all bay. Then gradually, when July arrive, they go to the south the nearest the coasts, and they are outflow through the south entrance of bay at the end of August.3) The catch of anchovy was highest on July, poor second on August, and lowest on June. The chlorophyll-a and the turbidity influenced remarkably on the distribution and movement of anchovy school and the influence of chlorophyll-a was alrgest.
A Study on the Distribution of Marine Litters in the Eastern Part Area of the Southern Sea -mainly on Discarded Pots-
Journal of the Korean society of Fisheries Technology , volume 35, issue 4, 1999, Pages 386~390
The survey of the marine litter which has sunk and accumulated on the sea-bed was conducted over a 3-years period from 1996 to 1998 in eastern part area of the Southern sea. The obtained results are as follows :There are many pots as many as to be occupies 655 of collected marine litters. The distribution of pots in area A is much more than that of pots in area B, and the near Hongdo island has the most pots compared with other areas. The density of pots is the highest when the depth is 61~70 meters.
A basic study for the behaviour control of sevenband grouper, Epinephelus septem fasciatus, to underwater low frequency sound I. The Auditory thresholds of sevenband grouper
Journal of the Korean society of Fisheries Technology , volume 35, issue 4, 1999, Pages 391~396
It is well known that fish hear a wide frequency range of sound using both laterial line and inner ear, and the sound is probably the most effective channel for long-range communication underwater than any other stimulus.The auditory threshold of svenband grouper, Epinephelus septem fasciatus was determined by conditioning method using a sound coupled with electric shock in a tank. The audio-signals and electric shock used in the experiment were pure tones of 100 to 1000Hz and DC 6n.The response of fish to the sound was observed by ECG intervals from precordial leads method (V1·V2 method). The auditory threshold curve for sevenband grouper was V-shaped, with most sensitive threshold at 350Hz in the range of 100~1000Hz. The Sevenband grouper were more sensitive to sounds of 200~400Hz than to adjacent frequencies.
Response of Amberjacks, Seriola quinqueradiata to the Attracting lamp
Journal of the Korean society of Fisheries Technology , volume 35, issue 4, 1999, Pages 397~403
The author examined the response of Amberjacks, Seriola quinqueradiata [TEMMINCI et SCHLIBEL] to the surface attracting lamps (0.5W, 0.8W, 1W) line in the experimental water tank (550 L
73Hcm).The attracting rate was investigated in accordance with the intervals of lighting and putting out hour (1,5 minute) when each of the attracting lamps was gradually switched off after they were switched on all at once. The results are as follows:1. Total distribution rate of fish in the illuminated section was 92.4% (mean 18.5%) in case of 1 minute interval, and 95.8% (mean 19.2%) in case of 5 minutes interva. 2. Mean distribution rate of fish at the illuminated section: Distribution rate at interval of 1 minute were 19.0% in 1W, 18.4% in 0.5W, and 18.0% in 0.8W respectively. distribution rate at interval of 5 minutes were 19.5% in 1W, 19.2% in 0.5 W, and 18.8% in 0.8W respectively.3. Attracting rates of the last section showed very much increasing as illuminating time elapsed, but there was a little difference of attracting rates according to interval and lighting source. 4. Attracting rate of fish in only last section switched on : Attracting rate at interval in case of 1 minute were 97.0% in 1W, 86.0% in 0.8W and 74.0% in 0.5W respectively. Attracting rate at interval in case of 5 minutes were 97.3% in 1W, 90.0% in 0.5W and 88.0% in 0.8W respectively.
Target strength of fishes for estimating biomass -Distribution characteristics and target strength measurement of micronektonic fish, Maurolicus muelleri in the East Sea
Journal of the Korean society of Fisheries Technology , volume 35, issue 4, 1999, Pages 404~409
The in situ target strengths of, maurolicus muelleri were measured by the split beam echo sounder system at the frequency of 38kHz.Target strengths were measured during the night time in order to obtain the pure separated echoes from the scattered individual. And also it was to establish reasonable threshold due to taking the signals like as the planktons and etc.Since Maurolicus muelleri is a typical micronektonic fish, they mainly consisted of deep scattering layers(DSLs), and had a vertical migration perrodically during daytime and at night.We found that the Maurolicus muelleri occupied about 99% of total catch. Total length ranged from 4.5 to 5.7cm with a mean of 5.2cm and a standard deviation of 0.22cm.The target strengths of Maurolicus muelleir ranged from -60.4 to - 52.7dB and -59.2 to - 52.5 dB in the water layer of 10~30m and 30~50m depth, perspectively. Mean target strength was -57.1dB/fish and -28.5dB/kg. The target strength had the relation with the total length of the fish as, TS=20logL-71.4.
A Study on the Interlaminar Fracture Toughness of Glass Fiber Reinforced Plastic Comosites
Journal of the Korean society of Fisheries Technology , volume 35, issue 4, 1999, Pages 410~420
The value of the mode I interlamina fracture toughness, GIC, is calculated by experimental compliance method, modified compliance method and beam theory. The value of the mode II interlamina fracture toughness, GIC, is evaluated by beam method, theory beam theory and compliance method. This paper describes the effect of load pint displacement rate and speicimen geometries for mode I and II interlaminar fracture toughness of glass fiber reinforced plastic composites by using double cantilever beam (DCB) and end notched flexure (ENF) specimen. For the load point displacement rate of increases whereas the value of 2,6 and 10 mm/min the value of GIC decrease as load point displacement rate increases whereas the value of GIC is found to be no significant effect. The value of GIC decreases as initial crack length increases. The fractured surface of the DCB and ENF samples are examined by scanning electron microscopy (SEM).
A Study on the Impact Fracture Behavior of Glass Fiber Polypropylene Composites
Journal of the Korean society of Fisheries Technology , volume 35, issue 4, 1999, Pages 421~427
The critical fracture energy and failure mechanisms of GF/PP composites are investigated in the temperatures range of the ambient temperature to
The critical fracture energy increase as fiber volume fraction ratio increased The critical fracture energy shows a maximum at ambient temperature and it tends to decrease as temperature goes up. Major failure mechanisms can be classfied such as fiber matrix debonding, fiber pull-out and/or delamination and matrix deformation.
The Effect of High Pressure Chamber's Shape on the Characteristics of Annular Jet Pump
Journal of the Korean society of Fisheries Technology , volume 35, issue 4, 1999, Pages 428~434
Experimental studies on the characteristics of annular jet pump were carried out in this paper. Jet pump can be used widely for the transportation of solid materials, farm produce and fishes. The effects of high pressure chamber on the characteristics of annular jet pump were sought in this paper. Experiments were done for three shapes of high pressure chamber, and for several lengths of the high pressure chamber. Three types of the high pressure chamber's entrances(
single inflow, and
double inflow) were tested. Water was used for both the primary fluid and secondary fluid. The results obtained in this study are as follows;
double inflow type is the most effective among the tested three types of the high pressure chamber's entrances. The efficiency of jet pump with 400mm of high pressure chamber length is the highest among the chamber lengths tested in this study, thus indicating appropriate chamber length is required to get an efficient.
A Study on the Stochastic Sensitivity Analysis in Dynamics of Frame Structure
Journal of the Korean society of Fisheries Technology , volume 35, issue 4, 1999, Pages 435~447
It is main objective of this approach to present a method to analyse stochastic design sensitivity for problems of structural dynamics with randomness in design parameters. A combination of the adjoint variable approach and the second order perturbation method is used in the finite element approach. An alternative form of the constant functional that holds for all times is introduced to consider the time response of dynamic sensitivity. The terminal problem of the adjoint system is solved using equivalent homogeneous equations excited by initial velocities. The numerical procedures are shown to be much more efficient when based on the fold superposition method: the generalized co-ordinates are normalized and the correlated random variables are transformed to uncorrelated variables, whereas the secularities are eliminated by the fast Fourier transform of complex valued sequences. Numerical algorithms have been worked out and proved to be accurate and efficient : they can be readily adapted to fit into the existing finite element codes whose element derivative matrices can be explicitly generated. The numerical results of two cases -2 dimensional portal frame for the comparison with reference and 3-dimensional frame structure - for the deterministic sensitivity analysis are presented.