• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.6
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• pp.916-922
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• 1997

This paper attempted to estimate mesh selectivity of gill nets for neon flying squid in the north Pacific Ocean. The 11 linear regressions, (P<0.05) were obtained using the data on catch ratios derived from mesh size combinations between two slightly different mesh sizes of 12 kinds of research gillnet (namely 33, 37, 42, 48, 55, 63, 72. 76, 86, 96, 105 and 115 mm in stretched mesh size). There was an increase in the optimum length with the increase in mesh size but standard deviation showed somewhat increase with the increase in the mesh size. The selectivity curves were well fitted to the length frequency distributions obtained from samples for the mesh sizes from 48 mm through 86 mm. For the mesh sizes of 33, 37 and 42 mm the DML (Dorsal Mantle Length) compositions were distributed towards the right hand-limb of the curves. The DML distributions from the 96 mm and larger meshes showed a trend towards the left hand-limb of the curves. The selectivity curves for different mesh sizes indicate that large mesh sizes catch a greater size range of squid, and the gill net fishery in the north Pacific Ocean captures effectively neon flying squid within the range of $9\~43cm$ DML.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.48 no.4
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• pp.352-359
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• 2012

For rebuilding and managing fish stocks and fisheries, the biological and socioeconomic evaluations on fisheries management regulations are important. This study aimed to estimate the economic effectiveness of different mesh sizes in the yellow croaker gillnet fishery. In particular, by comparing economic effects of mesh sizes, 50mm and 52mm, it aimed to provide the economic validity for increasing mesh sizes. Analytical results showed that the fishing revenue was higher in the vessels using a mesh size over 52mm than that in the vessels using a mesh size less than 50mm. In addition, the effect of fishing cost reduction was also larger in the vessels using a mesh size over 52mm than that in the vessels using a mesh size less than 50mm.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.57 no.3
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• pp.185-193
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• 2021

This study was conducted to evaluate the performance of the octopus pot according to mesh sizes. Entering behavior of Octopus minor and bait (Macrophthalmus japonicus) escape rate on the mesh sizes of the pots were investigated for six times in indoor tank. The sea trials for evaluating the performance of Octopus minor pot to different mesh sizes (22, 20 and 18 mm) were conducted for six times from 2017 to 2018 in the coastal sea of Deukyang Bay, the Republic of Korea. Behavior patterns of contact pot to leaved pot were more frequent than contact pot to bait search. When the octopus contacted to the pot, there was no clear search behavior to distinguish the mesh sizes. Total catch of 46% was accounted for 18 mm pots, followed by 34% at 20 mm and 20% at 22 mm (P < 0.05). Catch per unit effort was calculated as 30 g/pot at 22 mm, 44 g/pot at 20 mm and 59 g/pot at 18 mm. As a result of evaluating 50% selection of mantle length and weight on the mesh sizes, mantle length (mm) and weight (g) were 84.6 and 147.8 in 22 mm, followed by 20 and 18 mm.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.28 no.4
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• pp.371-379
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• 1992

In order to analyse the mesh selectivity for the trawl net, the fishing experiment was carried out by the training ship Saebada in the southern Korea Sea and the East China Sea from June 1991 to August 1992. The trawl net used in experiment has the trouser type of cod-end with cover net, and the mesh selectivity was examined for the five kinds of the opening mesh size in its cod-end part. The selection curves and the selection parameters were calculated by using a logistic function, S=1/(1+exp super(-(aL+b))), and in this case, a and b are the selection parameters and L is the body length of the target species of fishes. In this report, the four species of aquatic animals were analysed because the catch data were enough to calculate normally the selection curves and the selection parameters, and the results obtained are summarized as follows: 1. Trachurus japonicus; Selection parameters a and b in each cases of the opening mesh size of 51.2mm, 70.2mm, 77.6mm, 88.0mm and 111.3mm were respectively 0.5050 and -5.4283, 0.3018 and -4.9590, 0.3816 and -7.3659, 0.2695 and -5.7958, 0.2170 and -5.1226. 2. Photololigo edulis ; Selection Parameters a and b in each cases of the former mesh sizes were respectively 0.7394 and -6.1433, 0.3389 and -4.2366, 0.3286 and -5.1002, 0.2543 and -5.0049, 0.1795 and -4.8040. 3. Trichirus lepturus; Selection curves in the opening mesh size of 111.3mm was calculated unnormally. The selection parameters in the other opening mesh sizes were respectively 0.3790 and -5.2891, 0.2071 and -4.9164, 0.1292 and -3.1733, 0.1153 and -3.8497 in the order of former mesh sizes except 111.3mm. 4. Todarodes pacificus ; Selection curve in case of the opening mesh sizes, 70.2mm and 111.3mm were calculated unnormally. In the order cases of the opening mesh sizes, the selection parameters were respectively were 0.5766 and -6.0169, 0.3735 and -5.4633, 0.2771 and -5.7718 in the order of former mesh sizes except 70.2mm and 111.3mm.

• Journal of Food Hygiene and Safety
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• v.13 no.3
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• pp.196-200
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• 1998

The relationship between storage stability and calcium contents extracted from anchovy according to particle sizes was investigated in this paper. The results are as follows; 1. The acid value (A Y) and the peroxide value (POY) of anchovy were in the rank order of whole anchovy<35<50<80 mesh by particle sizes and 6<12<18<30 months by storage term. 2. The Calcium (Ca) and Phosphorus (P) contents extracted from anchovy were in the rank order of whole anchovy<35<50<80 mesh by particle sizes and 10<20<30 minutes by heating time. The extracted amount of Ca was the largest when anchovy particles with 80 mesh were heated for 30 minutes. In that case the amount of Ca in the anchovy stocks was 52.54 mg. 3. The amount ratio between Ca and P was in the rank order of 30<20<10 minutes by boiling time and indicated 1:3.99~5.16 by each part. The lowest ratio of Ca to P was 1:3.99 when anchovy particles with 80 mesh were heated for 30 minutes.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.1 no.1
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• pp.82-88
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• 1991

Determination of Cu, Fe, Ni, Pb, and Zn concentrations in coal and respirable coal dust were performed by atomic absorption spectrophotometry. The coal samples of 18 coal mines in Gangneung area were collected and 25 coal mines in Taebaek area. Crushed coal samples were divided into three mesh sizes. The results were as follows : 1. Metal concentrations of coals in Gangneung area by sieve sizes( -100/+200 mesh, -200/+325 mesh, -325 mesh) were as follows: Cu ; 20, 18, 19, Fe ; 1,830, 1,765, 1,107, Pb ; 6, 8, 14, Ni ; 17, 17, 14, Zn ; 4, 2, $4{\mu}g/g$, respectively. Metal concentrations in coals in Taebaek area by sieve sizes(-100/+200 mesh, -200/+325 mesh, -325 mesh) were as follows: Cu ; 30, 32, 26, Fe ; 1,741, 1,822, 1,773, Pb ; 8, 9, 7, Ni ; 13, 13, 13, Zn ; 8, 5, $4{\mu}g/g$, respectively. There were not significant differences of Cu, Fe, Ni, Pb, and Zn concentrations of coals statistically in Gangneung and Taebaek area by sieve size. 2. Metal concentrations of coals in Gangneung and Taeback area were as follows : Cu ; 19, 30, Fe ; 1,514, 1,778, Pb ; 9, 8, Ni ; 16, 13, Zn ; 3, $6{\mu}g/g$, respectively. Differences of copper and zinc concentrations of coal samples were significant between Gangneung and Taebaek area, but those of iron, nickel and lead concentrations were not significant. 3. Copper, iron, lead, nickel and zinc concentrations of coals and respirable coal dust were as follows : Cu ; 30, 6, Fe ; 1,779, 5,075, Pb ; 8, 7,814, Ni ; 13, 5,681, Zn ; 5, $134{\mu}g/g$, respectively. Differences of nickel, lead and zinc concentrations were significant between coals and respirable coal dust but those of copper and iron concentrations were not significant.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.29 no.3
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• pp.177-182
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• 1993

In order to estimate the mesh selectivity master curves and the optimum mesh size, experiments were made by the cover net method with the cod-ends of the five different the opening mesh sizes(51.2mm, 70.2mm, 77.6mm, 88.0mm and 111.3mm). After that 163 hauling were performed and there by investigated, on the training vessel Saebada in the Southern Korean Sea and East China Sea from June 1991 to August 1992. In this report, the mesh selectivity master curves were fitted by using logistic function(S=1/(1+exp super(-(aR+b))), R=(L-L sub(0))/(M-M sub(0)) and the optimum mesh sizes were estimated from each master curve. In this case, a and b are the selection parameters, M is the mesh size of each experimental cod-end. L is body length, L sub(0) and M sub(0) is the distance from the coordinate origine to intersection of linear regression between 25% and 50% selection length. The results obtained are summarized as follows; 1. Trachurus japonicus: Mesh selectivity master curve parameters: a and b were 2. 25, -4.73 respectively and optimum mesh size was estimated to be 79.3mm. 2. Trichiurus lepturus: Mesh selectivity master curve parameters: a and b were 0.81, -3.17 respectively and optimum mesh size was estimated to be 64.5mm. 3. Photololigo edulis: Mesh selectivity master curve parameters: a and b were 1.30m, -4.10 respectively and optimum mesh size was estimated to be 89.9mm. 4. Todarodes pacificus: Mesh selectivity master curve parameters: a and b were 1. 35, -3.45 respectively and optimum mesh size was estimated to be 89.4mm.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.46 no.3
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• pp.223-231
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• 2010

This paper showed the difference between the selectivity of gill net by least square method with polynomials in Kitahara's and that by maximum likelihood analysis for Japanese sandfish and Korean flounder. Catch experiments for Japanese sandfish using commercial vessels off the eastern coast of Korea were conducted with six different mesh sizes between October and December 2007 and those for Korean flounder with five different mesh sizes between 2008 and 2009. The mesh size of 50% probability of catch corresponding to biological maturity length of fish was not different between that by least square method and that by maximum likelihood analysis for Japanese sandfish, however, a little different for Korean flounder, that is, those mesh sizes of 50% probability of catch for biological maturity length of Korean flounder were 10.6cm and 10.1cm by least square method and maximum likelihood analysis, respectively.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.28 no.4
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• pp.360-370
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• 1992

In order to analyse the mesh selectivity for the trawl net, the fishing experiment was carried out by the training ship Saebada belonging to the National Fisheries University, in the Southern Korea Sea and the East China Sea from June 1991 to August 1992. The trawl net used in the experiment has the trouser type of cod-end with cover net and the mesh selectivity in the cod-end part. In this report, the species of fishes caught and the catch rate for them in accordance with different mesh sizes were analysed, and the result obtained are summarized as follows: 1) 145 species of aquatic animals were caught in totally 138 times of trawl operations. 2) The number of species mostly not to escape are 28, 22, 19, 16 and 11 respectively, in each opening mesh size, 51.2mm, 70.2mm, 77.6mm, 88.0mm and 111.3mm of cod-end. 3) In view that the use of the opening mesh size above 54mm in cod-end of trawl net in Korea, it is necessary to device a counterplan against the overfishing, for the 22 species of aquatic animals mostly not to escape in the cod-end of the large mesh sizes more than 70.2mm.

• Journal of Ceramic Processing Research
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• v.23 no.4
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• pp.436-442
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• 2022

Gallium nitride (GaN) substrates were ground in two different grinding wheel abrasive sizes of 270 and 800-mesh, and thechange in surface morphologies of the substrates and the depth of subsurface damage (SSD) were observed. With the 800-meshgrinding wheel, the surface roughness (SR) and the depth of SSD of the sample tended to decrease, which was not the casewith the 270-mesh grinding wheel. In the X-ray rocking curve, the sample exhibited some compressive stress with the 270-meshgrinding wheel, but with the 800-mesh grinding wheel, it demonstrated the occurrence of tensile stresses in the sample and adecrease in full width at half maximum (FWHM), which confirms an improvement in the crystallinity. In the Raman spectra,the compressive stress of the 270-mesh grinding wheel and the tensile stress of the 800-mesh grinding wheel were confirmedthrough peak shifts. Photoluminescence (PL) spectra confirmed that the intensity ratio of the yellow luminescence increasedat the 800-mesh grinding wheel, and a blue shift occurred further. These results indicate that the SR and the depth of SSDwere proportional to the abrasive grain size of the grinding wheel. At the same time, the increase in PL intensity at specificpeak positions indicates that the stress stemming from the grinding process was concentrated at the crystal surface. The abovemechanism is illustrated in a schematic diagram, which confirms the possibility of improving the grinding efficiency andsubsequent polishing processes in future applications.