• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.46 no.4
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• pp.430-440
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• 2010

To investigate the catches of jack mackerel fishery, a series of fishing experiments was conducted in the high seas of the southeastern Pacific Ocean ($30^{\circ}S-38^{\circ}S,\;82^{\circ}W-95^{\circ}W$) during the period of 9 August to 18 December, 2003 by commercial fishing vessel and research vessel. The number of 205 tows fishing was carried out in the southeastern Pacific Ocean. The total catch was 1,988 ton and CPUE was 2.4 ton/hour. CPUE showed high values in the frontal zone during the survey. Main target species caught from the experimental fishing were the jack mackerel, Trachurus murphyi (98.1%) and chub mackerel, Scomber japonicus (1.9%) as bycatch. Body length of the jack mackerel was different between female and male. The high mean catch per unit effort of jack mackerel was showed when the fishing ground of jack mackerel fishery was over the $110^{\circ}W$ in the southeastern Pacific Ocean. But the fluctuation of the catch per unit effort in the western part of fishing ground was not matched with those year. Reliable physical and oceanographical information will be useful for the efficiency of fishing activity. According to the result of monthly movement of center of fishing ground, the fishing activity of jack mackerel fishery was performed northward in the southeastern Pacific Ocean as time passes.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.48 no.3
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• pp.187-194
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• 2012

This study surveyed the fishing efficiency for Japanese common squid based on improvements made to LED fishing lamps by utilizing the training ship of Gangwon Provincial College. The training ship, Haesong-ho (24 tons), was equipped with seventy-two 150W electric power LED fishing lamps (10.8kW), and their fishing efficiency and fuel consumption level were surveyed for a total of ten times during the period between June 15, 2009 and July 27, 2009. In addition, the training ship was equipped with seventy-one 300W electric power LED fishing lamps (21.3kW) and their fishing efficiency and fuel consumption level were surveyed for a total of five times during the period between January 17, 2010 and August 4, 2010. In order to compare the fishing efficiency of LED fishing lamps, the catch of another fishing vessel equipped with Metal Halide (MH) fishing lamps of 120kW for the same period and at the same fishing grounds. The fuel consumption levels during the fishing operation of Haesong-ho was about 1,047.7 liters which was approximately 19.9% of the total fuel consumption level of 5,262.6 liters, and the fuel consumption level per operation hour was on average 9.2 liters. The number of Japanese common squid caught by the LED fishing lamp-equipped fishing vessel ranged from 12 to 1,640 squid for each fishing trial and the average quantity was 652. The number of Japanese common squid caught by the MH fishing lamp-equipped 10 fishing vessels ranged from 40 to 4,800 squid and the average quantity was 2,055. The fishing of Japanese common squid was done by the use of hand lines and an automatic jigging machine. The number of Japanese common squid caught per hand line and a single roller of the automatic jigging machine was in the proportion of 50.8% to 49.2% with respect to the LED fishing lamp-equipped fishing vessel. However, the number of Japanese common squid caught per hand line and a single roller of the automatic jigging machine was in the proportion of 86.4% to 13.6% with respect to the MH fishing lamp-equipped fishing vessel where most of the catch was made by hand lines. On the other hand, in comparing the number of Japanese common squid caught per automatic jigging machine, the number of squid caught by the LED fishing lamp-equipped fishing vessel was about the same or greater than the number of squid caught by the MH fishing lamp-equipped fishing vessel.

• The Korean Journal of Malacology
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• v.24 no.3
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• pp.189-197
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• 2008

In order to develop the sustainable ecological management, short-necked clams, Ruditapes philippinarum, were collected from Yoengi coast in Tongyoeng, Korea. The growth of the clam was estimated as: $L_f=68.08{\cdot}(1-e^{-0.145(t+0.324)})$ from ring radius composition of shell. Instantaneous co-efficiency of total mortality and natural mortality were calculated as: 0.991/year and 0.494/year, respectively. The age of the clams from the first capture was estimated to be 3.28. The total biomass was estimated to be 212 MT in the fisheries area (6.4 ha). Applied by these parameters, the annual recruit biomass and the current yield per recruit were calculated to be 649.5 individual/$m^2$ and $0.7\;g/m^2$, respectively. The current fishing intensity was much lower for maximum sustainable yield and acceptable biological catch. Although higher yield per recruit could be achieved by increasing fishing intensity, it is favorable to retain the current fishing intensity because of the unique fishing attitude on Yeongi coast in Tongyoeng, Korea.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.53 no.4
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• pp.317-326
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• 2017

Comparative fishing experiments were conducted in the eastern coastal waters near Uljin, Korea from 2002 to 2004, using the experimental trammel nets to estimate the selectivity for spinyhead sculpin Dasycottus setiger. The inner panels of the nets were made of nylon monofilament with four mesh sizes (82.2, 89.4, 104.8, and 120.2 mm) while its two outer panels were made of twisted nylon multifilament with a mesh size of 510 mm. The SELECT (Share Each Length's Catch Total) procedure with maximum likelihood method was applied to obtain a master selection curve. The different functional models (normal, lognormal, bi-normal, and logistic model) were fitted to the catch data. The lognormal model with the fixed relative fishing intensity was chosen as the best-fitted selection curve through comparison of model deviance and AIC (Akaike's Information Criterion). The optimum relative length (the ratio of fish total length to mesh size) with the maximum relative efficiency was obtained as 2.492.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.44 no.3
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• pp.184-193
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• 2008

For environment-friendly fishery, the lead sinkers of octopus drift line were developed with the environmentfriendly sinker, and their characteristics and performance were investigated. To make the environmentfriendly sinker, the hydrate ceramic material was developed, and to increase the weight and strength, the iron power was added to it. The fishing hook was machine-made, and standardized, by using 60cm iron wire. For the manufacture of the sinker, the first, the mold was made, and then, hydrate ceramic material and water were quantitatively mixed. The mixture was poured into the mold prepared with a fishing hook already inserted, and had hardened for several hour, before it was taken out of the mold as a complete sinker. The sinkers were made in the 8 types ranging in weight from 150 to 500g, and their specific gravities were diverse from 2.871 to 6.637, which was 0.19 to 0.44 times lower than that of lead. The movement of the environment-friendly sinker by flume tank was possible in the weaker current speed than the similar lead sinker. In the coastal fishing grounds of Gangwon province, the comparison of catching efficiency was made between the improved fishing gears composed of the environment-friendly sinkers and artificial baits, and the current used fishing gears of lead sinkers and pig-fat baits. The result showed the tendency in which the improved fishing gears caught the bigger octopuses than the current used fishing gears. In the quantity and number of the fish catch per unit fishing gear, the improved fishing gear showed a little more catch than the current used fishing gear, regardless of the fishing area. However, the number of the improved fishing gears lost during fishing operation was similar to that of the current used fishing gears.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.54 no.3
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• pp.224-230
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• 2018

Squid is one of the important fisheries resources in Korea. Therefore, squid has been designated and managed as a target species of total allowable catch (TAC) since 2007, but the catch amount is gradually decreasing. The analysis was conducted to identify the change of relative fishing power index to develop the vessel and gear technology that may have improved the fishing efficiency of the offshore squid jigging fishery from 1960s to 2010s. Gross tonnage per fishing vessel increased with the increase in size until 1990, but then gradually decreased to 41.0 tons in 2000 and 37.1 tons in 2010. The illuminating power (energy consumption) by fishing lamps increased to 180 kW in 2005 and stabilized to 120 kW in 2015. Jigging machine started to be supplied to fishing vessels from the early 1970s, and fish finders began to be supplied in the early 1980s and gradually increased. Therefore, the relative fishing power index in the offshore squid jigging fishery increased from 1.0 in 1980 to 1.1 in 1990, to 3.5 in 2000 and to 2.5 in 2010, but the increment rate slowed down gradually. The results are expected to contribute to reasonable fisheries stock management.

• Journal of Korean Society on Water Environment
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• v.20 no.5
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• pp.525-533
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• 2004

The object ofthis study was to test for STORMSYS process that composed Catch Basin and Stormsys(three units: vortex solids separator, filter media bed and vegetated filter strips). It could be applied to treat the first-flush non-point pollution materials on the road(especially, motorway). This study investigated that the runoff characteristics of non-point pollutions containing the heavy metal(Fe, Zn and Cu) by rainfall showed relatively high pollution concentration in the early-stage storm runoff on the road, which seems to be caused by the vehicular traffic, and showed the rapid reduction of pollution concentration on the basis of about 5mm rainfall volume. As the number of the non-rainy days were increased, the pollution concentration by storm runoff was increased, also. As a test result of this process, the average removal efficiency of BOD, $COD_{mn}$, SS, T-N and T-P over the testing period were 92.7%,88.6%,97.4%,93.0% and 93.3%, respectively. Also, the average removal efficiency of n-Hexane, Fe, Zn and Cu were 86.7%, 96.1%, 84.4% and 78.4%, respectively. As shown in the characteristics of storm runoff, the non-point pollution materials have high pollution concentration in the early-stage storm runoff on the road, the installation of STORMSYS process is expected to reduce considerable amount of non-point pollutions.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.47 no.8
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• pp.541-548
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• 2019

In this paper, the required amount of heat for an anti-icing system of a Flush Air Data Sensing(FADS) system is predicted. For an efficient prediction during the early stage of a design process, a handbook method is used. A program of which inputs are flight conditions is developed to predict the required amount of heat. A CFD analysis is conducted to compute the water catch efficiency which is one of the core parameters used in the handbook method. Kriging method, one of well-known regression mothods, is utilized to construct a surface contour database to evaluate impingements of droplets. To predict the trajectories of droplets, the database of a flow field around the surface is built using Kriging method as well.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.30 no.4
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• pp.292-298
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• 1994

Catching performance of a mechanized pollock longline system compared with traditional one were examined in order to evaluate the practicality during two cruises in the Sokcho area. Mechanized longline system consists of random baiter, bait cutting machine, storage rails, and line hauler. Baiting efficiency of random baiter was 90-95% with 4-5kt shooting speed. Catching performance of the first experiment, salted sand lance only used as a bait. shows no significant difference between mechanized operation with use fresh sand lance as a bait caught significantly more pollock than traditional one with use salted sand lance (P<0.016). Improved catch rates were about 2 times. As soak time goes on, relative catching efficiency shows a steady increase up to 6~7 hours and thereafter gradually decrease.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.22 no.4
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• pp.61-70
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• 1986

In accordance with a rapid growth of demani on aquatic animals, researches of the unused fishery resources On the deep sea b~d in the Korean Waters has been and will be required. The authors carried out a series of fishing experiments to investigate the available resources and to find the effective fishing method on the deep sea bed of the Korean East Sea. In the experiments, 19 kinds of traps which are different from each other in shape, mesh size and entrance diameter were used. The fishing experiments w~r;; carried out in four areas of 20Dm, 600.'11, 800m and 1000.'11 deep respectively, by the Pusan 402 (30:) GT) and the Pusan 403 (279GT), the training ships of National Fisheries University of Pusan, during August, 1986. The catc~ were analyzed with the size, the depth and the construction of traps. The results obtained can be summarized as follows: 1. Main species of the catch w~re pink shrimp, Pandalus bolelis, a kind of welks, Buccimum striatissimum and a kind of larg~ crabs. Chiono8cetes japonicus and the another species were few. 2. The CPUE value (expressed by the number of catch per trap in this paper) of pink shrimp was the highest in the depth of 20J-n around, and the value in the depth of 600.'11 or more decreased gradually with an increase of the depth. But, the value of Buccimum straitissimum was much higher in the depth of 6:J:)!1I or more than that in the depth of 200m around. On the other hand, the value of Chion:Jecetes japonjcus was very low in general. 3. The iniividual body size of the catch differed with the depth. Pink shrimps caught in the depth of 200m around were smaller than those in the depth of 600.'11 or more. In contrast with this, Baccimum striatissim:t.m caught in the depth of 200m around were larger than those in the depth of 600.'11 or more. 4. Depending on the selection curve in Ishida's method for the mesh size of trap webbing, the carapace length of pink shrimp and the shell length of Buccimum striatissimum which are equivalent to 100% relative catching efficiency can be estimated about 3.5cm and 6.5cm or so respectively. 5. The number of catch of pink shrimp and Buccimum striatissimum by the 60.'1'1.'11 entrance diameter of trap were less than that by the 90mm, 120mm and 150mm, even thogh the diffierence am~r, g 9:Jmm, 120.'11.'11 and 150:1'.'11 are not so large.