• Fisheries and Aquatic Sciences
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• v.24 no.11
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• pp.383-389
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• 2021

On the southern coast of South Korea, dark-banded rockfish, sea bass, and red seabream are caught by single-line fishing. In particular, red seabream and sea bass are caught in the Jeollanam-do region using gear with attached fishing hooks, such as longline and single-line gear, with live shrimp as bait. The objective of this study was to compare the catch efficiency of two types of live shrimp (naturally grown Shiba shrimp [Metapenaeus joyneri] and cultured whiteleg shrimp [Litopenaeus vannamei]) used as bait. The investigation included interviews, on-board surveys, and water tank experiments. Interviews were conducted with relevant parties to determine the preference for live shrimp as bait, and the results showed a greater preference for cultured whiteleg shrimp. Further, an on-board survey was conducted to compare catch efficiency between these two types of live shrimp bait for single-line fishing. The on-board investigations were conducted once or twice a month between June and October. In total, the amounts of fish caught using naturally grown Shiba shrimp and cultured whiteleg shrimp were 56 and 52, respectively. Of these, the numbers of sea bass, the primary target fish species, caught using naturally grown Shiba shrimp and cultured whiteleg shrimp were 43 and 40, respectively. Thus, the results showed that there was almost no difference in the number of fish caught based on the bait used. However, according to a water tank experiment, cultured whiteleg shrimp survived longer than naturally grown Shiba shrimp.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.30 no.1
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• pp.1-12
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• 1994

Stow-net is originally spreaded with a lifting beam and a depressing beam. The net is improved by using canvas-made spreading devices by Mr. Han and his colleagues in the beginning of 1980's. The net is improved again by changing the partial shape of netting and arrangement of net pendants so as to be fitting with the actual performance of the net by Dr. Lee and his colleagues since 1988. The author studied to compare the fishing efficiency of those two kinds of nets(The former which was improve by Mr. Han is expressed as a traditional net and the latter improved again by Dr. Lee is expressed as an improved net in the present study). Twenty-one stow-netters concerned with the present study were selected among those based on the Port of Inchon, and were classified into two groups-eleven of them are a traditional net used group and ten are an improved net used group. The data on the fishing operation from August 1992 to March 1993, including the catch, the price of sell, the fishing operated times in every cruise and the fished position noticed by every stow-netter were offered by concerned stow-netters. From the data the times of operation, catch and value in every cruise were extracted and analyzed. The results obtained can be summarized as follows: 1. The times of operation in cruise were 13.7 by the traditional net used group and 12.7 by the improved net used group. 2. The mean catch per cruise showed 10.1M/T in the traditional net used group and 12.2M/T in the improved net used group, so the latter showed 21% better. 3. The mean catch per operation showed 0.7M/T in the traditional net used group and 0.9M/T in the improved net used group, so the latter showed 28% better. 4. The rate of three important species(starks, hair tail and croakers) in the total catch showed 83%, and the catch showed greater by the improved net used group at the rate of starks 141%, hair tail 110%, croakers 107%. 5. The rate of three important species in the total price showed 82%, but the price of starks which occupied the biggest in catch showed merely 5%, then the economical efficiency appeared low. 6. The mean price per stow-netter and per operation showed about 20%, greater respectively by the improved net used group and the mean price per operation by two important species(hair tail and croakers) showed greater about 30% by the improved net used group.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.30 no.3
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• pp.150-160
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• 1994

Drift gillnet fishery for neon flying squid in the North pacific was one of the major pelagic fisheries of Korea until 1992, its annual catch was 79, 000M/T as average during 1988-1992, but moratoriumed since 1993 according to the decision of UN. Therefore, for the developing of the new fishing gear for the squid, the seven types of rip hook by automatic squid jigging machine were experimented by the korean research vessel Pusan 851 (G/T 1.126, 2.600 PS) in the North Pacific (38 $^{\circ}$30'-43 $^{\circ}$N, 152 $^{\circ}$E-178 $^{\circ}$W) from July 6. 1993 to August 31. 1993. The investigation on catch rate, dropout rate, and catch condition of the rip hooks related to the fishing lamp power for aggregating the squid were carried out during the period. The results obtained are as follows: The composition of catch by automatic squid jigging machine was 83.9% for neon flying squid. 15.5% for boreopacific gonate squid. 0.6% for boreal clubhook squid, and 0.01% for luminous flying squid. The catch rate of neon flying squid was 94.6% in 13.6-18.3$^{\circ}C$ of surface water temperature and 5.4% in others. The higher catch rate of neon flying squid was made in the range 13.6-18.3$^{\circ}C$ of temperature at the surface and about 1$0^{\circ}C$ of temperature at the 100m layer. The CPUE of neon flying squid in the 13.6-18.3$^{\circ}C$ of surface water temperature was ranged 0.8-11.8kg (8.7kg as average). The mantle length and body weight of neon flying squid caught in the experiment were ranged 18.3-51.3 cm, 140-3, 980g and mean mantle length and mean body weight were 29.4cm, 972g respectively. The catch rate of neon flying squid was the highest at dawn with a value of 25.0% of the total catch. The body weight of neon flying squid caught by the D type hooks was 1.7 times more than that of the A type hooks. The dropout rate of neon flying squid caught by the seven types hooks was 7.9-57.5% (19.0% as average), and dropout rate of the D type hooks was 7.9% with 2.7 times decrease than that of the A type hooks. The catch efficiency of small sized neon flying squid in case of using on-off switch method on fishing lamp in 15 minutes intervals was 2.6 times higher than that of the on-switch method with same fishing lamp power.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.42 no.4
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• pp.195-202
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• 2006

To determine the relative efficiency and mesh selectivity of gill net for the Pacific saury, Cololabis saira, a series of fishing experiments was carried out in the Northwest Pacific Ocean from August 13 to October 13 in 2002, using gill nets of different mesh size(30, 33, 35, 37, 39 and 42mm) constructed from two kinds of twine material(monofilament, twisted multifilament nylon web). The relative efficiency of two material gears was expressed as the ratio obtained by dividing monofilament catch by multifilament catch in number. The master selection curve of each material gear was estimated by applying the extended Kitahara's method. The catch of experimental gears is mostly Pacific saury(98.6%), Cololabis saira. The kinds of bycatch are common squid(0.7%), Pacific mackerel(0.6%), etc. Catch comparisons in the two gears showed that monofilament nylon nets are 1.7 times more efficient. The optimum values in monofilament and multifilament gill net for Pacific saury are 8.28 and 8.23, respectively.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.41 no.2
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• pp.95-100
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• 2005

In order to improve the gill nets for croaker, Miichthys miiuy which is proper to the fishermen's income ans fisheries resource management, we had studied to the net height of present gill nets (mesh size 160mm, 50 mesh in depth), experimental gill nets-I(mesh size 150mm, 68 mesh in depth) and experimental gill nets-II(mesh size 142mm, 75 mesh in depth) in wter using the gill nets design ans analysis simulation system, and then investigated and analyzed the catch efficiency of each gill nets through the field fishing experiments. The net height of emperimental gill nets-I and experimental gill nets-II in water were estimated respectively about 1.5 times and 1.3 times higher than present gill nets which the net height is about 3.5m as the results of simulation considering the current of fishing fields. Total number of croakers which were caught by the persent gill nets was 62(body length 300~1,200mm), total catch weight was 398.7kg (mean 0.6kg/sheet). Total number of croakers which were caught by the experimental gill nets- I was 68(body length 600~1,100mm), total catch weight was 391.6kg (mean 1.2kg/sheet). Total number of croakers which were caught by the experimental gill nets-II was 28(body length 400~900mm), total catch weight was 99.2kg (mean 0.3kg/sheet).

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.47 no.4
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• pp.290-299
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• 2011

Field tests were carried out with five different mesh sizes (86.6, 101.0, 121.2, 137.7, 151.5mm) to study the relative efficiency of monofilament and multifilament gill net for Marbled sole, Pleuronectes yokohamae, in the western sea of Korea, 2007-2009. The relative efficiency was analyzed by length distribution, catch in number, catch in weight and weight per individual for Marbled sole. Statistical T-test was done to verify the efficiency between two gears. In the field tests, the total body length range, catch in number and weight of Marbled sole was 15.8-48.2cm, 728 and 254,939g, respectively. During the field tests, Marbled sole less than 15cm length which is prohibition size of fishing was not caught, but the caught number of Marbled sole less than 19.5cm length which is first maturity length was 13 (1.8%) and the caught number of Marbled sole more than 19.5cm was 715 (98.2%). Catches of monofilament gill net was average 1.4 times more efficient than multifilament gill net. The weight per individual and total length by mesh sizes in the two gears tended to gradually increase according to mesh size increasing. But there was little difference of weight per individual and total length by mesh sizes between two gears.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.47 no.3
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• pp.183-193
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• 2011

This study made a comparative analysis of behavioral reaction of squid to red (624nm), green (524nm), blue (460nm) & white LED light, its arrival time for the shadow section by making the shadow section in the central section of a water tank just like the bottom part of a squid jigging vessel, and on-site catching efficiency of LED fishing lamp with control fishing vessel. The color LED light showing the highest squidgathering rate as against the shadow section was found to be blue LED light with 39.3% rate under the dark (0.05lx) condition. Under the brighter condition than 0.05lx, white LED light was found to have the highest gathering rate of 41.5%. In addition, it was found that squid gathering rate was high at the shadow section which showed 6.3-fold brightness difference between the shadow section and bright section. As for the arrival time for the shadow section, blue LED light was found to be the fastest in attracting squids in 192.7 seconds under the dark condition while the red LED light was the fastest in luring squids in 164.6 seconds under the bright condition. The ratio of the squid-jigging operation and sailing in fuel consumption of the fishing vessel loaded with LED fishing lamp is about 7 to 1, showing most of the fuel is consumed more in sailing than in squid-jigging operation. As for a catch of squid, the control vessel loaded with MH (Metal Halide) fishing lamp had more catch of 600-7,080 squids than the vessel loaded with LED fishing lamp having a catch of 260-1,700 squids. In addition, even in the comparison of a catch per automatic jigging machine, the catch of the vessel loaded with MH fishing lamp excelled that of the vessel loaded with LED fishing lamp in 6 operations of squid jigging out of 9 operations. The ratio of hand-jigging and automatic jigging machine (one line) in the LED fishing lamp vessel was 1:1.1 excepting the case of having a catch only using an automatic jigging machine, showing almost the same with each other in catches, while in case of a MH fishing lamp vessel, its ratio against hand-jigging was 1 to 5.8, showing hand-jigging excelled in catches.

• Knowledge Management Research
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• v.17 no.2
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• pp.27-50
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• 2016

Korean manufacturing industry have recently faced the catch-up of China in the mass commodity product, such as automotive, display, and smart phone in terms of market as well as technology. Accordingly, discussion on the importance of achieving catch-up in complex product systems (CoPS) has been increasing as a new innovation engine for the industry. In order to achieve successful catch-up of CoPS, we explored emerging technologies of CoPS, which are featured by the characteristics of radical novelty, relatively fast growth and self-sustaining, through the study of emerging technologies of gas turbine for power generation. We found that emerging technologies of the gas turbine are technologies for combustion nozzle and composition of electrical machine for increasing power efficiency, washing technology for particulate matter, cast and material processing technology for enhancing durability from fatigue, cooling technologies from extremely high temperature, interconnection operation technology between renewable energy and the gas turbine for flexibility in power generation, and big data technology for remote monitoring and diagnosis of the gas turbine. We also found that those emerging technologies resulted in technological progress of the gas turbine by converging with other conventional technologies in the gas turbine. It indicates that emerging technologies in CoPS can be appeared on various technological knowledge fields and have complementary relationship with conventional technologies for technology progress of CoPS. It also implies that latecomers need to pursue integrated learning that includes emerging technologies as well as conventional technologies rather than independent learning related to emerging technologies for successful catch-up of CoPS. Our findings provide an important initial theoretical ground for investigating the emerging technologies and their characteristics in CoPS as well as recognizing knowledge management strategy for successful catch-up of latecomers. Our findings also contribute to the policy development of the CoPS from the perspective of innovation strategy and knowledge management.

• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.6
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• pp.113-119
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• 2014

For the robust design of Motor Driven Power Steering (MDPS) systems, it is important to consider energy efficiency from every aspect such as system configuration and current flow, etc. If design optimization is not considered, it has many problems on a vehicle. For example, when evaluating steering test, particularly the Catch-up test which turning the steering wheel left or right quickly, steering effort should be increased rapidly. Also a vehicle might have poor fuel efficiency. In this study, it is calculated energy consumption for each component of the steering system and analyzed factors of energy consumption. As a result, this paper redefines a method to estimate steering input torque using characteristics of vehicle electric components and then conducts an analysis of contribution for the Catch-up.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.40 no.3
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• pp.182-188
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• 2004

It has been, in general, known that the catching efficiency of a trammel net is better than that of a gill net because of the variability of catch species and size. In this stidy, A fishing gear test was carried out to analyze the catching efficiency of the gill net and the trammel net on the coast of Geomun-do of southern Korean waters and fish school aggregation was also investigated using a underwater video camera. CPUE of the gill net was 49.2% higher than the trammel net but fish species was 34.5% lower where there was no difference on the significance level of 5% by ANOVA test. Main catch species caught by the gill net were red seabream(Pagrus major) and triggerfish(Aluterus monoceros), skate ray(Raja Kenojei) and red seabream for the trammel net, and the average body length of red seabream was shorter than the trammel net. It was thought that the reason of higher catch in the gill net than the trammel net was a fish school which can be caught easily by gill net and the size of population was suitable for the gill net.