Pub Date : 2009-05-31DOI: 10.3796/KSFT.2009.45.2.085
Bong-Seong Bae, Byoung J. Park, Eui-Cheol Jeong, Yongsu Yang, Hae-Hoon Park, Y. Chun, D. Chang
The fishing lamp is a fishing gear that gathers fish at night. But the cost of oil, which is used to light fishing lamp, has been risen significantly up to 30-40% of total fishing costs. Therefore it is very urgent to develop an energy economical fishing lamp in order to solve the business difficulties of fisheries. Under this background, this research aims at developing a fishing lamp for squid jigging and hairtail angling fishery using the LED, which has excellent energy efficiency and durability. The LED fishing lamp developed can be controlled to fix a fit direction of fish shoal deep because a fishing lamp can be adjustable up and down directions. One unit of fishing lamp has about an 80Watt capacity and the frame of fishing lamp is made of aluminium to emit generated heat of LED to outside. The LED lamp developed was highly durable, only 5.7% of emitting efficiency decreased for 18 months. The illuminance of a unit LED lamp was 2,070lux at 1m and 21lux at 10 m distance, and the intensity of LED lamp system emitted 2,580lux and 400lux at the respective distances. After development of this fishing lamp, 100 units are installed on operating fishing vessels. Experimental results show that energy consumption of squid jigging and hairtail angling was reduced by 40% and 87%, respectively. In conclusion, our methods showed elevated fishing power, compared with traditional fishing method: 37.7% for squid jigging and 24.5% for hairtail angling.
{"title":"Design and performance evaluation of fish-luring system using the air-cooled LED lamp for jigging and angling boat","authors":"Bong-Seong Bae, Byoung J. Park, Eui-Cheol Jeong, Yongsu Yang, Hae-Hoon Park, Y. Chun, D. Chang","doi":"10.3796/KSFT.2009.45.2.085","DOIUrl":"https://doi.org/10.3796/KSFT.2009.45.2.085","url":null,"abstract":"The fishing lamp is a fishing gear that gathers fish at night. But the cost of oil, which is used to light fishing lamp, has been risen significantly up to 30-40% of total fishing costs. Therefore it is very urgent to develop an energy economical fishing lamp in order to solve the business difficulties of fisheries. Under this background, this research aims at developing a fishing lamp for squid jigging and hairtail angling fishery using the LED, which has excellent energy efficiency and durability. The LED fishing lamp developed can be controlled to fix a fit direction of fish shoal deep because a fishing lamp can be adjustable up and down directions. One unit of fishing lamp has about an 80Watt capacity and the frame of fishing lamp is made of aluminium to emit generated heat of LED to outside. The LED lamp developed was highly durable, only 5.7% of emitting efficiency decreased for 18 months. The illuminance of a unit LED lamp was 2,070lux at 1m and 21lux at 10 m distance, and the intensity of LED lamp system emitted 2,580lux and 400lux at the respective distances. After development of this fishing lamp, 100 units are installed on operating fishing vessels. Experimental results show that energy consumption of squid jigging and hairtail angling was reduced by 40% and 87%, respectively. In conclusion, our methods showed elevated fishing power, compared with traditional fishing method: 37.7% for squid jigging and 24.5% for hairtail angling.","PeriodicalId":211073,"journal":{"name":"Bulletin of The Korean Society of Fisheries Technology","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124736871","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-05-31DOI: 10.3796/KSFT.2009.45.2.106
Il–Kwon Kang, Hyung-seok Kim, Min-seok Kim, Jeong-Chang Kim, A. Lee
For the safety and cost reduction in the navigation, the automatic and intelligent system has been developedfor the vessel, and the most important factor in the system is to decide the collision risk exactly. In thispaper, we propose an advanced collision risk decision system for collision avoidance of the system. Theconventional researches using DCPA and TCPA for calculating the collision risk have a problem to producea same collision risk regardless of bearings for the ships, if they are located in the same distance from ownship. To solve this problem, in addition to DCPA and TCPA, we introduce the factor of VCD(variation ofcompass degree) and constant, CR which derived from COLREG72(International Regulation for PreventingCollision at Sea, 1972) for evaluating the collision risk including even the burden of own ship navigator dueto the encountering angle of each vessels. We decided the collision risk legally by the rule considering therelative situation of vessels. And therefore, the proposed system has two advantages, of which one is toproduce more detail collision risk and another is to reflect the real underway situation in conformity with therule.Key words : DCPA, TCPA, VCD, CR, Collision risk, Colreg 72
为了提高船舶航行的安全性和降低航行成本，船舶自动智能系统得到了发展，而碰撞风险的准确判定是该系统的关键。在本文中，我们提出了一种先进的碰撞风险决策系统来避免系统的碰撞。传统的研究中，如果船舶与船舶的距离相同，无论船舶的方位如何，使用DCPA和TCPA计算碰撞风险都会产生相同的碰撞风险。为了解决这一问题，我们在DCPA和TCPA的基础上，引入了来自COLREG72(International Regulation for PreventingCollision at Sea, 1972)的VCD(variation ofcompass degree)因子和CR常数，用于评估船舶的碰撞风险，甚至包括由于船舶的碰撞角而给自己的导航员带来的负担。考虑到船舶的相关情况，根据规则依法确定碰撞风险。因此，该系统具有两个优点，一是能够更详细地反映船舶的碰撞风险，二是能够符合规则地反映船舶的真实航行情况。关键词:DCPA, TCPA, VCD, CR，碰撞风险，coreg 72
{"title":"Collision risk considering the international regulations for preventing collisions at sea, 1972","authors":"Il–Kwon Kang, Hyung-seok Kim, Min-seok Kim, Jeong-Chang Kim, A. Lee","doi":"10.3796/KSFT.2009.45.2.106","DOIUrl":"https://doi.org/10.3796/KSFT.2009.45.2.106","url":null,"abstract":"For the safety and cost reduction in the navigation, the automatic and intelligent system has been developedfor the vessel, and the most important factor in the system is to decide the collision risk exactly. In thispaper, we propose an advanced collision risk decision system for collision avoidance of the system. Theconventional researches using DCPA and TCPA for calculating the collision risk have a problem to producea same collision risk regardless of bearings for the ships, if they are located in the same distance from ownship. To solve this problem, in addition to DCPA and TCPA, we introduce the factor of VCD(variation ofcompass degree) and constant, CR which derived from COLREG72(International Regulation for PreventingCollision at Sea, 1972) for evaluating the collision risk including even the burden of own ship navigator dueto the encountering angle of each vessels. We decided the collision risk legally by the rule considering therelative situation of vessels. And therefore, the proposed system has two advantages, of which one is toproduce more detail collision risk and another is to reflect the real underway situation in conformity with therule.Key words : DCPA, TCPA, VCD, CR, Collision risk, Colreg 72","PeriodicalId":211073,"journal":{"name":"Bulletin of The Korean Society of Fisheries Technology","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129867424","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-05-31DOI: 10.3796/KSFT.2009.45.2.096
Bong-Seong Bae, Hae-Hoon Park, Eui-Cheol Jeong, Heui–Chun An, Yongsu Yang, Y. Chun
For an effective management of fisheries resources, we need fisheries informations necessary for the establishment of reasonable fishing effort and TAC distribution. We carried out fishing research using trammel nets in the coastal sea of Susan-port(Yangyang, Gangwondo, Korea) and Hupo-port(Uljin, Gyeongbukdo, Korea) and analyzed fishing power variation of the fishing gear in terms of species composition, condition and so on for both sites. A total of 29 species were caught with most dominant species of Hippoglossoides dubius followed by Pseudopleuronectes herzensteini, Lophius litulon and Alcichthys elongatus in Susan. The total number of species caught in Hupo was 37 species with most dominant species of Todarodes pacifius followed by Lophius litulon, Hexagrammos agrammus and Pseudopleuronectes herzensteini. CPUE of Susan fishing area per trammel net was 12.74 fish and 2.00kg on average, while it was 6.80 fish and 2.27kg on average for Hupo. The fishing power index for both sites was 1, placing the two fishing grounds in a same level.
{"title":"An analysis on catch and fishing power of trammel nets by fishing ground","authors":"Bong-Seong Bae, Hae-Hoon Park, Eui-Cheol Jeong, Heui–Chun An, Yongsu Yang, Y. Chun","doi":"10.3796/KSFT.2009.45.2.096","DOIUrl":"https://doi.org/10.3796/KSFT.2009.45.2.096","url":null,"abstract":"For an effective management of fisheries resources, we need fisheries informations necessary for the establishment of reasonable fishing effort and TAC distribution. We carried out fishing research using trammel nets in the coastal sea of Susan-port(Yangyang, Gangwondo, Korea) and Hupo-port(Uljin, Gyeongbukdo, Korea) and analyzed fishing power variation of the fishing gear in terms of species composition, condition and so on for both sites. A total of 29 species were caught with most dominant species of Hippoglossoides dubius followed by Pseudopleuronectes herzensteini, Lophius litulon and Alcichthys elongatus in Susan. The total number of species caught in Hupo was 37 species with most dominant species of Todarodes pacifius followed by Lophius litulon, Hexagrammos agrammus and Pseudopleuronectes herzensteini. CPUE of Susan fishing area per trammel net was 12.74 fish and 2.00kg on average, while it was 6.80 fish and 2.27kg on average for Hupo. The fishing power index for both sites was 1, placing the two fishing grounds in a same level.","PeriodicalId":211073,"journal":{"name":"Bulletin of The Korean Society of Fisheries Technology","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129993642","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-05-31DOI: 10.3796/KSFT.2009.45.2.122
Chang–Doo Park, Heui–Chun An, Samkwang Cho, Bong-Seong Bae, Hae-Hoon Park, J. Bae, Hyun-Young Kim
the extended Kitahara s method. The selection curve showed that the gill nets of larger mesh size allowed more female crabs of small carapace size to escape. The optimum values of RL/m for 1.0 of retention probability was 0.563 and RL/m was estimated to be 0.249, 0.290, 0.319, 0.344 and 0.367 when the retention probability were 0.1, 0.2, 0.3, 0.4 and 0.5, respectively.
{"title":"Size selectivity of gill net for female snow crab, Chionoecetes opilio","authors":"Chang–Doo Park, Heui–Chun An, Samkwang Cho, Bong-Seong Bae, Hae-Hoon Park, J. Bae, Hyun-Young Kim","doi":"10.3796/KSFT.2009.45.2.122","DOIUrl":"https://doi.org/10.3796/KSFT.2009.45.2.122","url":null,"abstract":"the extended Kitahara s method. The selection curve showed that the gill nets of larger mesh size allowed more female crabs of small carapace size to escape. The optimum values of RL/m for 1.0 of retention probability was 0.563 and RL/m was estimated to be 0.249, 0.290, 0.319, 0.344 and 0.367 when the retention probability were 0.1, 0.2, 0.3, 0.4 and 0.5, respectively.","PeriodicalId":211073,"journal":{"name":"Bulletin of The Korean Society of Fisheries Technology","volume":"80 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130130484","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-03-31DOI: 10.3796/KSFT.2008.45.1.014
Byung-Yeob Kim, Chang-Heon Lee
This experimental study was carried out to obtain the base data for saving the man power in the fishingoperation of largehead hairtail hand line by using the continuous type hand line system with a rotary devicewhich could make a main line move automatically. In order to solve the twists and entangling on the mainline happened during operating test, the resistance board was suspended at the end of the main line at sea. Asthe result, there were no problems of tangling and so on due to up and down moving of a main line.According to the control of a fixed angle of guide roller, it was possible to prevent the main line to beseparated from a side roller and a guide roller. In addition, PVC tube between a guide roller and a side rollerenabled a main line to be moved smoothly without any entanglement.Key words : Continuous type hand line, Side roller, Guide roller, Guide tube, Resistance board
{"title":"A basic study on the improvement of the continuous type fishing system for largehead hairtail hand line in coastal area of Jeju island, Korea","authors":"Byung-Yeob Kim, Chang-Heon Lee","doi":"10.3796/KSFT.2008.45.1.014","DOIUrl":"https://doi.org/10.3796/KSFT.2008.45.1.014","url":null,"abstract":"This experimental study was carried out to obtain the base data for saving the man power in the fishingoperation of largehead hairtail hand line by using the continuous type hand line system with a rotary devicewhich could make a main line move automatically. In order to solve the twists and entangling on the mainline happened during operating test, the resistance board was suspended at the end of the main line at sea. Asthe result, there were no problems of tangling and so on due to up and down moving of a main line.According to the control of a fixed angle of guide roller, it was possible to prevent the main line to beseparated from a side roller and a guide roller. In addition, PVC tube between a guide roller and a side rollerenabled a main line to be moved smoothly without any entanglement.Key words : Continuous type hand line, Side roller, Guide roller, Guide tube, Resistance board","PeriodicalId":211073,"journal":{"name":"Bulletin of The Korean Society of Fisheries Technology","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124978512","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-03-31DOI: 10.3796/KSFT.2008.45.1.001
Choong-sik Jang, Youngwan Cho, Chae-Rok Lim, Bo-Yeon Kim, Young-Su An
Experimental fishing operation by the shrimp beam trawl was carried out to investigate the bycatch in order to develop the selective fishing gear of the shrimp beam trawl fishery. The experimental trawling was performed by the prototype fishing gear in coast sea of Boryeong, Buan, Kangjin, Tongyeong and Geoje from 30 April to 13 November 2005. Bycatches of the experimental trawling were analyzed species composition, total length composition. The results obtained can be summarized as follows; Target fishes caught by the shrimp beam trawl were Palaemon gravieri, Crangon Hakodatei, Trachysalambria curvirostris, Parapenaeopsis tenellus, Rhynchocinetes uritai and Matapenaeus joyneri. And their fishing rate and total length range were 50.0%, 46.0%, 2.6%, 0.4%, 0.3%, 0.3% and 40-80mm, 40-80mm, 120-150mm, 60-80mm, 60-80mm, 60-120mm respectively. Bycatches caught by the shrimp beam trawl consisted of fishes of 30 kinds, 6 kinds of mollusk, 5 kinds of shellfishes and 3 kinds of crabs. The main fish was Engraulis japonicus, Platycephalus indicus, Paralichthys olivaceus, Leiognathus nuchalis and Conger myriaster, their occupied rate were 47.0%, 16.6%, 13.6%, 5.5%, 2.7% respectively, and their total length range were 60-150mm, 80-410mm, 80-600mm, 30-80mm and 150-460mm respectively. A number bycatch rates of shrimp beam trawl fishery were 99.7% in Buan, 60.0% in Kangjin, 14.6% in Boryeong, 10.6% in Tongyeong and 2.7% in Geoje, The weight bycatch rate were 99.9% in Buan, 75.1% in Kangjin, 57.1% in Tongyeong, 47.4% in Boryeong and 15.4% in Geoje.
{"title":"An analysis on catch of the shrimp beam trawl fishery in Korea coastal sea","authors":"Choong-sik Jang, Youngwan Cho, Chae-Rok Lim, Bo-Yeon Kim, Young-Su An","doi":"10.3796/KSFT.2008.45.1.001","DOIUrl":"https://doi.org/10.3796/KSFT.2008.45.1.001","url":null,"abstract":"Experimental fishing operation by the shrimp beam trawl was carried out to investigate the bycatch in order to develop the selective fishing gear of the shrimp beam trawl fishery. The experimental trawling was performed by the prototype fishing gear in coast sea of Boryeong, Buan, Kangjin, Tongyeong and Geoje from 30 April to 13 November 2005. Bycatches of the experimental trawling were analyzed species composition, total length composition. The results obtained can be summarized as follows; Target fishes caught by the shrimp beam trawl were Palaemon gravieri, Crangon Hakodatei, Trachysalambria curvirostris, Parapenaeopsis tenellus, Rhynchocinetes uritai and Matapenaeus joyneri. And their fishing rate and total length range were 50.0%, 46.0%, 2.6%, 0.4%, 0.3%, 0.3% and 40-80mm, 40-80mm, 120-150mm, 60-80mm, 60-80mm, 60-120mm respectively. Bycatches caught by the shrimp beam trawl consisted of fishes of 30 kinds, 6 kinds of mollusk, 5 kinds of shellfishes and 3 kinds of crabs. The main fish was Engraulis japonicus, Platycephalus indicus, Paralichthys olivaceus, Leiognathus nuchalis and Conger myriaster, their occupied rate were 47.0%, 16.6%, 13.6%, 5.5%, 2.7% respectively, and their total length range were 60-150mm, 80-410mm, 80-600mm, 30-80mm and 150-460mm respectively. A number bycatch rates of shrimp beam trawl fishery were 99.7% in Buan, 60.0% in Kangjin, 14.6% in Boryeong, 10.6% in Tongyeong and 2.7% in Geoje, The weight bycatch rate were 99.9% in Buan, 75.1% in Kangjin, 57.1% in Tongyeong, 47.4% in Boryeong and 15.4% in Geoje.","PeriodicalId":211073,"journal":{"name":"Bulletin of The Korean Society of Fisheries Technology","volume":"56 11","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114020842","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-03-31DOI: 10.3796/KSFT.2008.45.1.022
Youjung Kwon, D. An, D. Moon, Seon-Jae Hwang, Jae Bong Lee, Distant Water
Ecological risk assessment(ERA), developed in Australia, can be used to estimate the risk of target, bycatch and protected species from the effects of fishing using limited data for stock assessment. In this study, we employed the ERA approach to estimate risks to tunas, billfishes, sharks, sea turtles and other species by the Korean tuna longline fishery in the Western and Central Pacific Ocean using productivity and susceptibility analyses of the ERA based on low( 1.84). Albacore, bigeye, yellowfin, skipjack and bluefin tunas were generally evaluated in the medium risk. The susceptibility of tuna species, however, had higher risks than the productivity. Billfishes were also at medium risk, while sharks were at high risk by the tuna longline fishery. The risk of productivity was generally high, because most sharks caught by the tuna longline fishery have high longevities, i.e., over 10 years, including ovoviviparous species. Susceptibility, which is related with the selection of fishing gear, was also high, because the longline fishery has no gear modifications to prevent bycatch of protected species. Not only target tuna species were influenced by the tuna longline fishery in the Western and Central Pacific Ocean, but also non- target species, such as pomfret, mackerels rays, sea turtle were done. Ecosystem-based fishery assessment
{"title":"An ecological risk assessment for the effect of the Korean tuna longline fishery in the Western and Central Pacific Ocean","authors":"Youjung Kwon, D. An, D. Moon, Seon-Jae Hwang, Jae Bong Lee, Distant Water","doi":"10.3796/KSFT.2008.45.1.022","DOIUrl":"https://doi.org/10.3796/KSFT.2008.45.1.022","url":null,"abstract":"Ecological risk assessment(ERA), developed in Australia, can be used to estimate the risk of target, bycatch and protected species from the effects of fishing using limited data for stock assessment. In this study, we employed the ERA approach to estimate risks to tunas, billfishes, sharks, sea turtles and other species by the Korean tuna longline fishery in the Western and Central Pacific Ocean using productivity and susceptibility analyses of the ERA based on low( 1.84). Albacore, bigeye, yellowfin, skipjack and bluefin tunas were generally evaluated in the medium risk. The susceptibility of tuna species, however, had higher risks than the productivity. Billfishes were also at medium risk, while sharks were at high risk by the tuna longline fishery. The risk of productivity was generally high, because most sharks caught by the tuna longline fishery have high longevities, i.e., over 10 years, including ovoviviparous species. Susceptibility, which is related with the selection of fishing gear, was also high, because the longline fishery has no gear modifications to prevent bycatch of protected species. Not only target tuna species were influenced by the tuna longline fishery in the Western and Central Pacific Ocean, but also non- target species, such as pomfret, mackerels rays, sea turtle were done. Ecosystem-based fishery assessment","PeriodicalId":211073,"journal":{"name":"Bulletin of The Korean Society of Fisheries Technology","volume":"61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124834845","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-03-31DOI: 10.3796/KSFT.2008.45.1.034
Dae-Ho Song, Chun-woo Lee
In this study, the hydrodynamic coefficients were measured using various nettings to analyze the change of drag coefficients and lift coefficients as a basic study for deriving hydrodynamic coefficients. The data on hydrodynamic force obtained from the flume tank tests were used to compare and analyze the hydrodynamic coefficients based on Reynolds number. Standardized hydrodynamic coefficients were then assumed during the analysis procedures. The hydrodynamic coefficients were measured using the 9 kinds of nettings in which had the same total projected area with different diameters and mesh-grouping ratio. These different netting systems : mesh-grouping ratio. The results of the test of nettings were as follows; First, the drag coefficients of nettings increased when the higher attack angles applied, and decreased with the increased flow speed and netting twine diameter. Second, the lift coefficients of nettings showed the increased values until the attack angle 30 degree, but decreased for the attack angle over 40 degree. Third, the hydrodynamic coefficients of netting decreased as the Reynolds number increased, and reach at slightly states in the highest numbers. Fourth, the hydrodynamic coefficients were derived from a functional formula considering attack angles and Reynolds number, and presented in the three dimensional space.
{"title":"Study on the hydrodynamic coefficients of the nettings","authors":"Dae-Ho Song, Chun-woo Lee","doi":"10.3796/KSFT.2008.45.1.034","DOIUrl":"https://doi.org/10.3796/KSFT.2008.45.1.034","url":null,"abstract":"In this study, the hydrodynamic coefficients were measured using various nettings to analyze the change of drag coefficients and lift coefficients as a basic study for deriving hydrodynamic coefficients. The data on hydrodynamic force obtained from the flume tank tests were used to compare and analyze the hydrodynamic coefficients based on Reynolds number. Standardized hydrodynamic coefficients were then assumed during the analysis procedures. The hydrodynamic coefficients were measured using the 9 kinds of nettings in which had the same total projected area with different diameters and mesh-grouping ratio. These different netting systems : mesh-grouping ratio. The results of the test of nettings were as follows; First, the drag coefficients of nettings increased when the higher attack angles applied, and decreased with the increased flow speed and netting twine diameter. Second, the lift coefficients of nettings showed the increased values until the attack angle 30 degree, but decreased for the attack angle over 40 degree. Third, the hydrodynamic coefficients of netting decreased as the Reynolds number increased, and reach at slightly states in the highest numbers. Fourth, the hydrodynamic coefficients were derived from a functional formula considering attack angles and Reynolds number, and presented in the three dimensional space.","PeriodicalId":211073,"journal":{"name":"Bulletin of The Korean Society of Fisheries Technology","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130445024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-03-31DOI: 10.3796/KSFT.2008.45.1.046
Min Son Kim, H. Shin, M. S. Kim, J. Han
To compare and evaluate the suitability and comfort levels of the environment on board a stern trawltraining ship, KAYA(GT: 1737 tons, Pukyong National University), with the international standardizationguide ISO 6954:2000(E), measurements of the hull vibration on accommodation areas and working areas ofthe training ship from July 8 to July 10, 2008 were completed upon KAYAs linear sea route. The vibrationsalong the z-axis were measured with the use of a 3-axis vibration level meter, which included a marinevibration card. Results show accelerations of the vibrations on the passengers accommodation area to be42.0-115.8(average: 78.0, standard deviation(SD): 21.0) mm/s
{"title":"Boarding environment of training ship KAYA for the hull vibration","authors":"Min Son Kim, H. Shin, M. S. Kim, J. Han","doi":"10.3796/KSFT.2008.45.1.046","DOIUrl":"https://doi.org/10.3796/KSFT.2008.45.1.046","url":null,"abstract":"To compare and evaluate the suitability and comfort levels of the environment on board a stern trawltraining ship, KAYA(GT: 1737 tons, Pukyong National University), with the international standardizationguide ISO 6954:2000(E), measurements of the hull vibration on accommodation areas and working areas ofthe training ship from July 8 to July 10, 2008 were completed upon KAYAs linear sea route. The vibrationsalong the z-axis were measured with the use of a 3-axis vibration level meter, which included a marinevibration card. Results show accelerations of the vibrations on the passengers accommodation area to be42.0-115.8(average: 78.0, standard deviation(SD): 21.0) mm/s","PeriodicalId":211073,"journal":{"name":"Bulletin of The Korean Society of Fisheries Technology","volume":"359 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116683224","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-11-30DOI: 10.3796/KSFT.2008.44.4.304
Doo-Nam Kim, Young-Seung Kim
Patagonian toothfish(Dissostichus eleginoides) was investigated in the southeastern Atlantic Ocean during the period of 19 March to 7 July 2007 by commercial bottom longliners. The number of 116 hauls were carried out individually in this study area by two bottom longliners during 111 days. The total catches were 89,559kg(9.91kg/100hooks) and 66,758kg(7.38kg/100hooks), respectively. Most Patagonian toothfishes were caught on the 46-48 S, 6-11 E of southeastern Atlantic Ocean. Patagonian toothfish comprised 67.01- 92.49%(by weight) of the catches in the southeastern Atlantic Ocean. No Antarctic toothfish (Dissostichus mawsoni) was caught during the surveys. Patagonian toothfish was found throughout the experimental area, but the density was considerably greater in the layer of 1,300-1,900m, where 49.88% of the fishes were caught. Smaller fishes were generally distributed to the shallow waters and larger fish were more frequently caught with the depth. Mean size of Patagonian toothfish increased with depth of capture. Accordingly economically profitable fishing activities for the Patagonian toothfish fishery requires an understanding of the size distribution of the Patagonian toothfish by depth.
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