간행물
수산해양기술연구 KCI 등재 Journal of the Korean Society of Fisheries and Ocean Technology 韓國漁業技術學會誌
- 발행기관 한국수산해양기술학회(구 한국어업기술학회)
- 자료유형 학술지
- 간기 계간
- ISSN 2671-9940 (Print)2671-9924 (Online)
- 수록기간 1965 ~ 2024
- 주제분류 농수해양 > 수산학 농수해양 분류의 다른 간행물
- 십진분류KDC 529DDC 639
권호리스트/논문검색
권호
51권 2호 (2015년 5월) 15건
1.
2015.05
구독 인증기관 무료, 개인회원 유료
Abalone (Haliotis discus hannai) is a shellfish that feeds on kelp and, as a product, it can often achieve a high market value. However, the dissolved oxygen (DO) levels in coastal waters in Korea have been negatively impacted by pollution from many anthropogenic sources. Herein, a computational fluid dynamics (CFD) software package was used to analyze the distribution of the DO concentration within an abalone containment structure. A finite volume approach was used to solve the Reynolds-averaged Navier–Stokes equations combined with a k–ε turbulence model to describe the flow. The distribution of DO was determined within the control volume domain, and the transport equations of the pollutants were interpreted using a CFD model. The CFD analysis revealed that more than 60% and 30% of the relative oxygen concentration in one and two containers, respectively, was maintained when the flow acts along the six sheets of polyethylene plates. Therefore, it is clear that the abalone plate shelters should be placed parallel to the flow.
4,000원
2.
2015.05
구독 인증기관 무료, 개인회원 유료
Recently LED fish-attracting lamps have been more widely used in fisheries as low-cost and high-efficiency fishing gear, and development of long-life high-efficiency lamps is required through the design of LED packages to optimize heat resistance. This study developed an improved LED fish-attracting lamp with excellent heat performance, which was verified using a numerical model. Heat-resistance design factors such as the heat-radiation fin shape, PCB type, and LED chip count were investigated and optimized. Comparison with a commercial 180-W LED fishing lamp showed that the increase in initial temperature was 40% higher than that of the surrounding LED chip because of design errors in contact thermal resistance. The 250-W LED lamp developed in this study has a characteristic with thermal rising in linearly stable according to the heat source. In addition, luminance efficiency was improved by 20-65% by using flow-visualization simulation. A decrease of 45% in total power consumption with a fuel-cost reduction of over 55% can be expected when using these optimized heat release design factors.
4,000원
3.
2015.05
구독 인증기관 무료, 개인회원 유료
Selectivity and by-catch are the main features used to define fish catch for fisheries management or to determine fishing gear efficiency. A fish girth distribution analysis was carried out to determine the retention rate of juveniles discarded and to establish common selectivity for a multispecies catch. Total body length, body weight, and girth of juvenile fish retained in the cod-end and cover net separately were collected using an 18-mm mesh cover net during 12 fishing trials with a 41-mm cod-end beam trawl. The by-catch weight ratio in the cod-end was twice that of the by-catch ratio in number. The 50% selectivity of body length and 50% girth of redfin velvet fish were not significantly different between the cod-end and cover net, whereas those of other fish species were significantly different between the cod-end and cover net. The difference in 50% selectivity girth of other fish between the cod-end and cover net was similar between cod-end mesh size and cover net mesh size. Furthermore, the difference in 50% body length selectivity of other fish between the cod-end and cover net was almost double the difference in girth. Girth selectivity in a multispecies catch using towed fishing gear was effectively used to determine fish and net mesh size.
4,000원
4.
2015.05
구독 인증기관 무료, 개인회원 유료
Experiments designed to measure the effect of LED (light–emitting diode) light wavelength on the growth of fingerling rockfishes (Sebastes inermis) were conducted. Fingerling rockfishes (average body weight of individual: 1.13g) were divided into two groups by wavelength of the LED light [light power: 1,620 mW; wavelength: 518 nm (green color), 622 nm (red color)]. Triplicate groups of 180 individuals were reared over 7 weeks. Lighting duration was 14 hours from 06:00 to 20:00. A water tank exposed on the natural light in a room through the windows was used as a control. At results of the first experiment [initial average body weight (BW) of individual: 1.13 g; standard deviation (SD): 0.13 g], the final individual BW exposed on the green color was increased 0.39 g than the red color, and decreased 0.12 g than the natural light in the room. At results of the second (initial individual BW: 5.07 g; SD: 0.70 g) and the third experiment (initial individual BW: 10.67 g; SD: 0.67 g), the final individual BW exposed on the green color was increased 1.07 g and 2.55 g than the red color, respectively, and increased 0.57 g and 0.84 g than the natural light, respectively. The relative growth rate of the green color was higher about 8% significantly (p<0.05) than the natural light. In the case of the red color the relative growth rate was lower significantly (p<0.05) than the natural light.
4,000원
5.
2015.05
구독 인증기관 무료, 개인회원 유료
The powered purse seine fishery is an important fishery accounting for 19.4% of adjacent water fishery production in Korea, and the commercial fishing is associated with high rate of fatal and non-fatal occupational injury. The hazard analysis for the fishermen’s safety of offshore large powered purse seiner was conducted to serve as a basic data for improving the healthy and safe working environment of fishermen using fishermen’s occupational accidents of the national federation of fisheries cooperatives (NFFC) in 2013 (n=583). As a result, the occupational accident occurrence rate of this fishery was 182.6‰ in all industries 30.9 times the rate of that. In addition, death and missing rate was found to have a very serious level management to 25.1‱ in all industries of death of 17.5 times. The accident occurred in 72.3 to 85.8% was happened at sea. The others, slipping and struck by object etc occurred more frequently in order in the frequency of accident occurrence pattern. However, the occurrence rate of death and missing did not match the frequency of accident pattern. In other words, slipping occurred frequently higher while death and missing risk was not high. And the contact with fishing gear and fall in the waters was low while death and missing risk was high. The results are expected to contribute for identification and assessment of safety hazard occurred in offshore large powered purse seiners.
4,000원
6.
2015.05
구독 인증기관 무료, 개인회원 유료
Hundreds of Steller sea lions, Eumetopias jubatus, migrate from Sakhalin and the northern Kuril Islands to Hokkaido in Japan every winter. During this migration, they may use their roaring sounds to navigate and to maintain their groups. We recorded the roars of wild Steller sea lions that had landed on reefs on the west coast of Hokkaido, and those of captive sea lions, while making video recordings. The fundamental frequency (F0), Formant frequency (F1), pulse repetition rate (PRR), and duration of syllables (T) were analyzed using a sonagraph. F0, F1, and PRR of the roars emitted by captive sea lions increased in the order male, female. By contrast, the F1 of wild males was lower than that of females, while the F0 and PRR of wild males and females did not differ statistically. These results suggest regional differences between the five groups showed that.
4,000원
7.
2015.05
구독 인증기관 무료, 개인회원 유료
The purpose of this study is to identify the flow resistance of the bottom pair trawl nets. The bottom pair trawl nets being used in fishing vessel (100G/T, 550ps) was selected as a full-scale net, and 1/10, 1/25 and 1/50 of the model nets were made. Converted into the full-scale net by Tauti’s modeling rule and Kim’s modeling rule, when resistance coefficient k of each net was calculated by substituting into above equation for flow resistance R and wall area of nets S values of each net v. Because resistant coefficient k decreases exponentially according as flow velocity v increases to make k cv-m, c and m values of each net were compared. As a result, as the model was smaller, c and m values was smaller in the two rule into standard of 1/10 model value, decrease degree of 1/25 model was almost same in the two rule, decrease degree of 1/50 model was very big in Tauti’s modeling rule. Therefore, in the result of experiment, because average of c and m values for similarly 1/10 and 1/25 model were given c=4.9 (kgf․s2/m4) and m=0.45, R (kgf) of bottom pair trawl net could show R =4.9Sv1.55 using these values. As in the order of cod-end, wing and bag part for 1/25 and 1/50 model net were removed in turn, measured flow resistance of each, converted into the full-scale, total resistance of the net and the resistance of each part net were calculated. The resistance ratio of each part for total net was not same in 1/25 and 1/50 model each other, but average of two nets was perfectly same area ratio of each part as the wing, bag and cod-end part was 43%, 45% and 12%. However, the resistance of each part divided area of the part, calculated the resistance of per unit area, wing and bag part were not big difference each other, while the resistance of cod-end part was very large.
4,000원
8.
2015.05
구독 인증기관 무료, 개인회원 유료
We examined the appearance of cold water in the southwest region of the East Sea, based on the sea surface temperature (SST) at the east coast of Korea and buoy data in Donghae (37°31’N, 130°00’E, 80 km east away from Donghae port) and Pohang (36°21’N, 129°46’E, 35 km east away from Ganggu port) from June to August in 2013. Also, the serial oceanographic data of National Fisheries Research and Development Institute (NFRDI) were used to see the oceanographic conditions for June and August in 2013. The SST anomaly at the east coast showed negative values in 3~6°C from 2 July. At Janggigab, the SST anomaly showed negative value amount to 10°C in 8 July. The negative values of SST anomaly continued to the middle of August at Janggigab. The wind speed was 6~11 m/s and the direction was south-southwestly in 1 July. The wind speed amounts to 6~16 m/s in 2 July. It means that the strong wind induced the upwelling effect by a day. The temperature was lower than normal at the depth in 20 m of the East Sea in June and August. The air pressure was 996~998 hPa in the beginning of July. It was the lowest air pressure during the studied period. The correlation was 0.3 between the SST anomaly and air pressure. It was suggested that the appearance of cold water in the East Sea was influenced by a stirring due to wind and low air pressure as well as coastal upwelling.
4,000원
9.
2015.05
구독 인증기관 무료, 개인회원 유료
During the study periods, total 143 individuals of Lateolabrax japonicus were collected. Body length (BL) range was 2.0–11.8 cm. Empty stomach occurred in 8.4%. The most abundant prey was copepods. Among copepods, Tigriopus japonicus was the most abundant prey appeared 32.1 in %F. Next important prey was shrimps and mysids. The results of analysis in ontogenetic changes, main prey of two small size classes (2.0–3.9 cm, 4.0–5.9 cm) were copepods. Thereafter, copepods percentage was decreased, but shrimps, mysids, fishes percentage was increased by increasing body length from 8.0 cm < size class.
4,000원
10.
2015.05
구독 인증기관 무료, 개인회원 유료
To obtain geographical range and growth–kinetics parameters of mottled sake (Beringraja pulchra) populations in the Yellow Sea, three mark–recapture experiments were carried out. Overall, 991 tagged individuals were released, and 4.1% of them were recaptured with the mean release period of 339 d (range, 8–1,420 d) and the mean growth rate of 1.4 cm mon–1 (female, 1.5 cm mon–1; male 1.3 cm mon–1). In the first experiment, 667 individuals were released at Heuksan Island from April to June, 2007–2009, and 30 individuals were recaptured mainly at the north and the north–east coasts of the island, indicating absence of migration to the south of the island. In the second experiment, 323 individuals were released at several fishing grounds scattered in the Yellow Sea in 2010–2013, and 11 individuals were recaptured at points deviated to all directions from the releasing points. As the last, one individual was released with pop–up satellite archival tag at a costal point (34°37.2’N, 124°59.3’E) off Hong Island on May 21, 2010. The tagged individual migrated to a north–east location (35°50.4’N, 126°03.6’E) of Eocheong Island by Aug. 25, 2010. The data archived for the three months in the tag indicated that the migration path had depths of 48–80 m and temperature of 12.6–14.4°C. The results indicated that mottled sake populations had a localized habitat ranges at the north of Heuksan Island and the west of Hong Island while growing at the rate of 1.4 cm mon–1.
4,000원
11.
2015.05
구독 인증기관 무료, 개인회원 유료
The multi-frequency characteristics of anchovy schools were investigated using six acoustic lines collected at 38 and 120 kHz while a primary trawl survey was conducted from 14 April and 18 April of 2014 in off the coast of Tongyeong and Geo–je. Here, the frequency characteristics mean ΔMVBS that is the difference of Mean Volume Backscattering Strength at two frequencies. To use the characteristics effectively, the optimal cell size (10×2 m) was determined by examining several different cell sizes in consideration with the shapes of fish schools and the ΔMVBS pattern. By examining 6 histograms of ΔMVBS, afternoon groups were occupied more in the ΔMVBS range of –6~–4 dB than that of –4~–2 dB, comparing to morning groups. The ΔMVBS range of the morning groups was between –16.9 dB and 11.6 dB, and that of the afternoon groups –16.7 dB and 13.0 dB. The average and standard deviation were –3.9±3.6 dB in the morning and –4.1±3.4 dB in the afternoon, suggesting that morning groups were 2 dB higher than afternoon groups. The ΔMVBS range of all anchovy schools regardless of morning and afternoon was between –16.9 dB and 13.0 dB, their average ΔMVBS was –4.1±3.5 dB. The characteristics can support to identify anchovy species in the waters where multiple fish species are distributed. It is hoped that this study presents the availability and benefit of acoustic data from a primary trawl survey.
4,000원
12.
2015.05
구독 인증기관 무료, 개인회원 유료
This study is intended to provide navigator with specific information necessary to assist the avoidance of collision and the operation of ships to evaluate the maneuverability of dead weight tonnage 8,000 tons Oil/Chemical tanker. The actual maneuvering characteristics of ship can be adequately judged from the results of typical ship trials. Author carried out sea trials based full scale for turning test in ballast condition and full load condition, semi balanced rudder and flap rudder. The turning circle maneuvering were performed on the starboard and port sides with 35° rudder angle at the normal continuous rating. The results from tests could be compared directly with the standards of maneuverability of IMO and consequently the maneuvering qualities of the ship is full satisfied with its.
4,300원
13.
2015.05
구독 인증기관 무료, 개인회원 유료
This study is intended to provide navigator with specific information necessary to assist the avoidance of collision and the operation of ships to evaluate the maneuverability of dead weight tonnage 8,000 tons Oil/Chemical tanker. The actual maneuvering characteristics of ship can be adequately judged from the results of typical ship trials. Author carried out sea trials based full scale for turning test, Z” maneuvering test, man overboard rescue maneuver test, inertia stopping test. Consequently, 2st Overshoot yaw angle of the semi balanced rudder and flap rudder in ±20° zig–zag test showed 22.2° and 18.0°, respectively. The maneuverability of the vessel was good in the flap rudder. The man overboard rescue maneuver maneuverability test was most favorable in the flap rudder and the full load condition. The results from tests could be compared directly with the standards of maneuverability of IMO and consequently the maneuvering qualities of the ship is full satisfied with its.
4,000원
14.
2015.05
구독 인증기관 무료, 개인회원 유료
The feeding habits of Okamejei kenojei were studied using 242 specimens collected from October 2010 to September 2011 in the coastal waters of Gadeok-do, Korea. O. kenojei was carnivorous feeder that consumed mainly shrimps, crabs, and fishes. Its diet also included small quantities of stomatods, cephalopods, amphipods. The size of O. kenojei ranged from 10.4 to 47.4 cm in total length (TL). O. kenojei showed ontogenetic dietary shift. <15.0, 15.0-19.9 cm size classes fed mainly on shrimps and amphipods. 20.0-24.9 cm size class fed mainly shrimps and crabs. Thereafter, shrimps and crabs were decreased with ontogenesis while fishes and cephalopods were increased. Increasing size, the mN/ST were constantly decreased, but mW/ST were constantly increased.
4,000원
15.
2015.05
구독 인증기관 무료, 개인회원 유료
The aim of this study is to find out the behavior and acoustic backscattering of the large jellyfish Nemopliema nomurai using hydroacoustics in situ. N. nomurai was distributed at depths ranging from 10~15 m during the day. Regarding the behavior of N. nomurai, there was no significant change in depth, and 3D tortuosity was not high. The vertical direction was ±10° from the horizontal, and moving speed was 0.9~1.5 m s–1.With regard to hydro–acoustical characteristics, the mean TS of N. nomurai ranged from –69.6~–56.0 dB at 38 kHz and –69.4~–54.5 dB at 120 kHz. TS variation (Max TS–Min TS) at 38 and 120 kHz was 0~10.2 dB and 0.2~16.0 dB, respectively. Mean TS and TS variation (Max TS–Min TS) of N. nomurai were higher at 120 kHz than at 38 kHz. The results showed that the use of hydroacoustics was effective in estimating the distribution depth, behavior, and acoustic characteristics of the target.
4,000원
