Pub Date : 2012-05-31DOI: 10.3796/KSFT.2012.48.2.155
D. Bae, Hag-Soo Kim, A. Zakki
The CSR rule was defined by IACS as the unified rule for a commercial ship like a bulk carrier and a tanker. It have been required more strict conditions for various parts like loading conditions, the local and girder strength, fatigue strength, FEM for the ship rule. It was changed in many parts of the ship rules. In this paper, the mid-parts of 17.5K DWT bulk carrier were optimized by the CSR rule. On the other hand, the modified artificial life algorithms with multi-object functions were developed for optimizing the scantling. It is possible to find multi-global optimum solutions in the multi-object functions. And it is faster and efficient than the artificial life algorithm. First, to be optimizing the scantling and the weight by CSR rule, that is calculated by the CSR rule. The next, the result is re-calculated by the modified artificial life algorithm with multi-object functions. The optimized results which are satisfied with the CSR rule like the minimum size and the thickness of stiffener and the minimum cost have been searched by the optimizing algorithm. And the results have been compared with the non-optimizing results.
{"title":"The optimum design for 75.5k DWT bulk carrier using the multi-object modified artificial life algorithm by CSR rule","authors":"D. Bae, Hag-Soo Kim, A. Zakki","doi":"10.3796/KSFT.2012.48.2.155","DOIUrl":"https://doi.org/10.3796/KSFT.2012.48.2.155","url":null,"abstract":"The CSR rule was defined by IACS as the unified rule for a commercial ship like a bulk carrier and a tanker. It have been required more strict conditions for various parts like loading conditions, the local and girder strength, fatigue strength, FEM for the ship rule. It was changed in many parts of the ship rules. In this paper, the mid-parts of 17.5K DWT bulk carrier were optimized by the CSR rule. On the other hand, the modified artificial life algorithms with multi-object functions were developed for optimizing the scantling. It is possible to find multi-global optimum solutions in the multi-object functions. And it is faster and efficient than the artificial life algorithm. First, to be optimizing the scantling and the weight by CSR rule, that is calculated by the CSR rule. The next, the result is re-calculated by the modified artificial life algorithm with multi-object functions. The optimized results which are satisfied with the CSR rule like the minimum size and the thickness of stiffener and the minimum cost have been searched by the optimizing algorithm. And the results have been compared with the non-optimizing results.","PeriodicalId":211073,"journal":{"name":"Bulletin of The Korean Society of Fisheries Technology","volume":"182 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123737854","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 : 2012-02-28DOI: 10.3796/KSFT.2012.48.1.051
Chin-Sung Yang, Suk-jong Kim
As abasic study to improve hooking ability of long line fishing gear, which is widely used around Jeju -docoast, the researcher performed hooking experiment of parrot fish by manufacturing and installing 7 kinds ofmodel long line fishing gears, whose thickness of branch line are different and 8 kinds of model long linefishing gear, whose length of branch line are different, in indoor circular aquarium , which is installed for themodel experiment of thickness and length of branch line that are various by fishing implement and improper.The hooking rate depending on thickness and length of branch line was calculated and the effect of thicknessand length of branch line on hooking rate was analyzed . Its results are as follows. When branch line was thinand long , high hooking rate appeared . In the scope of value setting , the relationship between thickness (
{"title":"The effect of hooking on thickness and length of branch line in fishing gear of long line at the coastal waters","authors":"Chin-Sung Yang, Suk-jong Kim","doi":"10.3796/KSFT.2012.48.1.051","DOIUrl":"https://doi.org/10.3796/KSFT.2012.48.1.051","url":null,"abstract":"As abasic study to improve hooking ability of long line fishing gear, which is widely used around Jeju -docoast, the researcher performed hooking experiment of parrot fish by manufacturing and installing 7 kinds ofmodel long line fishing gears, whose thickness of branch line are different and 8 kinds of model long linefishing gear, whose length of branch line are different, in indoor circular aquarium , which is installed for themodel experiment of thickness and length of branch line that are various by fishing implement and improper.The hooking rate depending on thickness and length of branch line was calculated and the effect of thicknessand length of branch line on hooking rate was analyzed . Its results are as follows. When branch line was thinand long , high hooking rate appeared . In the scope of value setting , the relationship between thickness (","PeriodicalId":211073,"journal":{"name":"Bulletin of The Korean Society of Fisheries Technology","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123596119","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 : 2012-02-28DOI: 10.3796/KSFT.2012.48.1.040
Gun-ho Lee, Bongjin Cha, Seong-Jae Jeong
This study aims to analyze the performance of a submersible fish cage which was designed for developing an economical cage system can be applied in korean aquaculture environment easily . To analyze the performance of the designed cage a model test was carried out . In the test , inclination changes of the upper frame and mooring tensions of model cage were measured during the submerging and surfacing motion in still water and wave condition (period : 2 s, wave height : 0.1, 0.2, 0.3 m). As a result , in the still water condition the model cage kept horizontal balance and inclination degree of the upper frame was about 1。 . In the wave condition , the model cage showed bilateral symmetric up-and-down motion but the average inclination degree of the upper frame was about 0 。 . When the model cage reached at a depth of 1m, the upand-down motion of the cage was decreased by 12% compared with that of at the surface (period 2s, height 0.3 m). In the same wave condition , the maximum and average line tension under the bottom position were about 8% and 11% respectively compared with that of at surface .
{"title":"Analysis of submerging characteristics and stability of the model submersible fish cage operated by buoyancy control","authors":"Gun-ho Lee, Bongjin Cha, Seong-Jae Jeong","doi":"10.3796/KSFT.2012.48.1.040","DOIUrl":"https://doi.org/10.3796/KSFT.2012.48.1.040","url":null,"abstract":"This study aims to analyze the performance of a submersible fish cage which was designed for developing an economical cage system can be applied in korean aquaculture environment easily . To analyze the performance of the designed cage a model test was carried out . In the test , inclination changes of the upper frame and mooring tensions of model cage were measured during the submerging and surfacing motion in still water and wave condition (period : 2 s, wave height : 0.1, 0.2, 0.3 m). As a result , in the still water condition the model cage kept horizontal balance and inclination degree of the upper frame was about 1。 . In the wave condition , the model cage showed bilateral symmetric up-and-down motion but the average inclination degree of the upper frame was about 0 。 . When the model cage reached at a depth of 1m, the upand-down motion of the cage was decreased by 12% compared with that of at the surface (period 2s, height 0.3 m). In the same wave condition , the maximum and average line tension under the bottom position were about 8% and 11% respectively compared with that of at surface .","PeriodicalId":211073,"journal":{"name":"Bulletin of The Korean Society of Fisheries Technology","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127186369","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 : 2012-02-28DOI: 10.3796/KSFT.2012.48.1.010
S. Kim, Seong-wook Park, Kyounghoon Lee, Yongsu Yang
참조기는 우리나라에서 오래 전부터 고급으로취급하고 있는 대표적인 어종 중의 하나로 우리나라 남서해 연안과 동중국해 등의 해역에서주로 어획되고 있다 . 최근 참조기 자원량은 증감을반복하고 있으나 전반적으로 감소 추세에 있다. 이와 더불어 주요 어장인 동중국해에서는 어획노력량이 과다하게 투입되고 있고 중국 어선들과 경쟁조업 등으로 유자망어업의 경우 어장사고가 빈번히 발생하고 있다 . 특히 생태적인 측면에서는 자원 감소로 인하여 개체의 성장과 성숙이 매우 빨라짐에 따라 성숙개체의 체장이 소형화되고 있다 . 이러한 관점에서 우리나라에서는남서해안 참조기를 자원 회복 대상어종으로
{"title":"The estimation of the optimum mesh size selectivity of a drift net for yellow croaker (Larimichthys polyactis ) using by the SELECT model","authors":"S. Kim, Seong-wook Park, Kyounghoon Lee, Yongsu Yang","doi":"10.3796/KSFT.2012.48.1.010","DOIUrl":"https://doi.org/10.3796/KSFT.2012.48.1.010","url":null,"abstract":"참조기는 우리나라에서 오래 전부터 고급으로취급하고 있는 대표적인 어종 중의 하나로 우리나라 남서해 연안과 동중국해 등의 해역에서주로 어획되고 있다 . 최근 참조기 자원량은 증감을반복하고 있으나 전반적으로 감소 추세에 있다. 이와 더불어 주요 어장인 동중국해에서는 어획노력량이 과다하게 투입되고 있고 중국 어선들과 경쟁조업 등으로 유자망어업의 경우 어장사고가 빈번히 발생하고 있다 . 특히 생태적인 측면에서는 자원 감소로 인하여 개체의 성장과 성숙이 매우 빨라짐에 따라 성숙개체의 체장이 소형화되고 있다 . 이러한 관점에서 우리나라에서는남서해안 참조기를 자원 회복 대상어종으로","PeriodicalId":211073,"journal":{"name":"Bulletin of The Korean Society of Fisheries Technology","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124385827","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 : 2012-02-28DOI: 10.3796/KSFT.2012.48.1.059
Gyu-Hyong Lee
In order to elucidate the mechanism of fishing condition variation of anchovy in the set net fisheries of Anggang Bay, the monthly catch of anchovy was analyzed and examined based on the data acquired from 2006 to 2010 in 13 different fishing grounds. Anchovy consistently appeared from April to December and reached the production of 840 to 1,424 t (average : 1,228 t), with a big annual variation. However, anchovy production in this area accounts for approximately 75% of the production by set net in Anggang Bay whereas it holds 6.8% of the nationwide production (
{"title":"Characteristics of fishing condition variation of anchovy in the set net fishing ground of Anggang bay, korea","authors":"Gyu-Hyong Lee","doi":"10.3796/KSFT.2012.48.1.059","DOIUrl":"https://doi.org/10.3796/KSFT.2012.48.1.059","url":null,"abstract":"In order to elucidate the mechanism of fishing condition variation of anchovy in the set net fisheries of Anggang Bay, the monthly catch of anchovy was analyzed and examined based on the data acquired from 2006 to 2010 in 13 different fishing grounds. Anchovy consistently appeared from April to December and reached the production of 840 to 1,424 t (average : 1,228 t), with a big annual variation. However, anchovy production in this area accounts for approximately 75% of the production by set net in Anggang Bay whereas it holds 6.8% of the nationwide production (","PeriodicalId":211073,"journal":{"name":"Bulletin of The Korean Society of Fisheries Technology","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132472472","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 : 2012-02-28DOI: 10.3796/KSFT.2012.48.1.072
Kangseok Hwang, J. Choi, T. Oh
Using artificial neural network (ANN) technique, auction prices for common mackerel were forecasted with the daily total sale and auction price data at the Busan Cooperative Fish Market before introducing Total Allowable Catch (TAC) system, when catch data had no limit in Korea. Virtual input data produced from actual data were used to improve the accuracy of prediction and the suitable neural network was induced for the prediction. We tested 35 networks to be retained 10, and found good performance network with regression ratio of 0.904 and determination coefficient of 0.695. There were significant variations between training and verification errors in this network. Ideally, it should require more training cases to avoid over-learning, which leads to improve performance and makes the results more reliable. And the precision of prediction was improved when environmental factors including physical and biological variables were added. This network for prediction of price and catch was considered to be applicable for other fishes.
{"title":"Forecasting common mackerel auction price by artificial neural network in Busan Cooperative Fish Market before introducing TAC system in Korea","authors":"Kangseok Hwang, J. Choi, T. Oh","doi":"10.3796/KSFT.2012.48.1.072","DOIUrl":"https://doi.org/10.3796/KSFT.2012.48.1.072","url":null,"abstract":"Using artificial neural network (ANN) technique, auction prices for common mackerel were forecasted with the daily total sale and auction price data at the Busan Cooperative Fish Market before introducing Total Allowable Catch (TAC) system, when catch data had no limit in Korea. Virtual input data produced from actual data were used to improve the accuracy of prediction and the suitable neural network was induced for the prediction. We tested 35 networks to be retained 10, and found good performance network with regression ratio of 0.904 and determination coefficient of 0.695. There were significant variations between training and verification errors in this network. Ideally, it should require more training cases to avoid over-learning, which leads to improve performance and makes the results more reliable. And the precision of prediction was improved when environmental factors including physical and biological variables were added. This network for prediction of price and catch was considered to be applicable for other fishes.","PeriodicalId":211073,"journal":{"name":"Bulletin of The Korean Society of Fisheries Technology","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114218273","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 : 2012-02-28DOI: 10.3796/KSFT.2012.48.1.082
K. Han
Four different buildings having various wall construction are analyzed for the effect of wall mass on the thermal performance and inside building air and wall temperature transient and also for calculating the energy consumption load . This analytical study was motivated by the experimental work of Burch et al . An analytical solution of one -dimensional , linear , partial differential equations is obtained using the Laplace transform method , Bromwich and modified Bromwich contour method . A simple dynamic model using steady state analysis as simplified methods is developed and results of energy consumption loads are compared with results obtained using the analytical solution . Typical Meteorological Year data are processed to yield hourly average monthly values . This study is conducted using weather data from two different locations in Korea : Daegu having severe weather in summer and winter and Jeju having mild weather almost all year round . There is a significant wall mass effect on the thermal performance of a building in mild weather condition . Buildings of heavyweight construction with insulation show the highest comfort level in mild weather condition . A proportional controller provides the higher comfort level in comparison with buildings using on -off controller . The steady state analysis gives an accurate estimate of energy load for all types of construction . Finally , it appears that both mass and wall insulation are important factors in the thermal performance of buildings , but their relative merits should be decided in each building by a strict analysis of the building layout , weather conditions and site condition .
{"title":"A study on the analytical method for calculating the inside air temperature transient and energy consumption load of the building using two different controllers","authors":"K. Han","doi":"10.3796/KSFT.2012.48.1.082","DOIUrl":"https://doi.org/10.3796/KSFT.2012.48.1.082","url":null,"abstract":"Four different buildings having various wall construction are analyzed for the effect of wall mass on the thermal performance and inside building air and wall temperature transient and also for calculating the energy consumption load . This analytical study was motivated by the experimental work of Burch et al . An analytical solution of one -dimensional , linear , partial differential equations is obtained using the Laplace transform method , Bromwich and modified Bromwich contour method . A simple dynamic model using steady state analysis as simplified methods is developed and results of energy consumption loads are compared with results obtained using the analytical solution . Typical Meteorological Year data are processed to yield hourly average monthly values . This study is conducted using weather data from two different locations in Korea : Daegu having severe weather in summer and winter and Jeju having mild weather almost all year round . There is a significant wall mass effect on the thermal performance of a building in mild weather condition . Buildings of heavyweight construction with insulation show the highest comfort level in mild weather condition . A proportional controller provides the higher comfort level in comparison with buildings using on -off controller . The steady state analysis gives an accurate estimate of energy load for all types of construction . Finally , it appears that both mass and wall insulation are important factors in the thermal performance of buildings , but their relative merits should be decided in each building by a strict analysis of the building layout , weather conditions and site condition .","PeriodicalId":211073,"journal":{"name":"Bulletin of The Korean Society of Fisheries Technology","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122600148","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 : 2012-02-28DOI: 10.3796/KSFT.2012.48.1.020
Seong-wook Park, S. Kim
The monofilament with 0.304mm of diameter was produced using a polybutylene succinate (PBS) resin, and a gill net was made by it. We investigated the impact of heat setting temperature on the mechanical properties, knot state and height of gill net. Heat treatment was carried out using the high pressure steam machine for 20 minutes at temperature of , , and . Before heat treatment, the strength and elongation of PBS monofilament were estimated to be , 23.8% at unknot, , 18.8% at single knot, , 22.9% at double knot in dry condition, respectively. The strength and elongation of PBS monofilament with double knot were decreased as heat setting temperature increased, and the decreasing rate of strength was showed to be higher than that of elongation. It was not found any differences in strength and elongation of PBS monofilament yarn with double knot at the and of heat setting temperature by 5% significance of T-test, but there was a significant difference at the and of heat setting temperature. The net`s height and length from leg to leg appeared no differences at the and of heat setting temperature. In results, it was investigated that the PBS monofilament gill net with the maximized physical properties could be manufactured at of heat setting temperature using a high pressure steam machine for 20 minutes.
{"title":"Effects of heat setting temperature conditions on the mechanical properties of Polybutylene succinate (PBS ) monofilament yarn after net -making","authors":"Seong-wook Park, S. Kim","doi":"10.3796/KSFT.2012.48.1.020","DOIUrl":"https://doi.org/10.3796/KSFT.2012.48.1.020","url":null,"abstract":"The monofilament with 0.304mm of diameter was produced using a polybutylene succinate (PBS) resin, and a gill net was made by it. We investigated the impact of heat setting temperature on the mechanical properties, knot state and height of gill net. Heat treatment was carried out using the high pressure steam machine for 20 minutes at temperature of , , and . Before heat treatment, the strength and elongation of PBS monofilament were estimated to be , 23.8% at unknot, , 18.8% at single knot, , 22.9% at double knot in dry condition, respectively. The strength and elongation of PBS monofilament with double knot were decreased as heat setting temperature increased, and the decreasing rate of strength was showed to be higher than that of elongation. It was not found any differences in strength and elongation of PBS monofilament yarn with double knot at the and of heat setting temperature by 5% significance of T-test, but there was a significant difference at the and of heat setting temperature. The net`s height and length from leg to leg appeared no differences at the and of heat setting temperature. In results, it was investigated that the PBS monofilament gill net with the maximized physical properties could be manufactured at of heat setting temperature using a high pressure steam machine for 20 minutes.","PeriodicalId":211073,"journal":{"name":"Bulletin of The Korean Society of Fisheries Technology","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124011644","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 : 2012-02-28DOI: 10.3796/KSFT.2012.48.1.029
Kyounghoon Lee, Pyungkwan Kim, Do-Hoon Kim, Heui–Chun An, Chun-woo Lee
Currently, environment-friendly and sustainable fisheries are one of the major issues among fisheries authorities. A variety of alternative management policies and projects are going on to enhance fisheries management systems and fishery resources such as a TAC management program and a VDS (Vessel Day Scheme) management scheme for distant water fishing nations in Western and Central Pacific Fisheries Commission (WCPFC) convention area. These kinds of efforts among fisheries management authorities are aimed at limiting fishing capacity or fishing power. In terms of fisheries management, Fishing capacity and fishing power have increased the importance of the impact on a fishery and level of the resources. Increased fishing capacity and fishing power have caused not only depletion of fisheries resource, but also additional fishing cost. therefore, there is a clear need for authorities to manage fishing capacity and fishing power. It is also help ensure the conservation and sustainability of the fishery resources. Because of lack of data, absolute fishing power is difficulty to measure. The notion of relative fishing power is frequently used. In this study, relative fishing power was assessed using Mastuda (1991) method for fishing power index. The raw data for assessment was based on fishermen`s logbook data from sampled fishing vessels in coastal snow crab gillnet fishery. Data Envelopment Analysis (DEA) method was used to assess fishing capacity. DEA is a linear programming methodology to measure the efficiency of a set of entities called Decision-Making Units (DMUs). It was recommended by FAO for assessing capacity in fisheries.
{"title":"Assessment of fishing power and fishing capacity of the snow crab (Chionoecetes opilio ) gillnet fishery in the East Sea","authors":"Kyounghoon Lee, Pyungkwan Kim, Do-Hoon Kim, Heui–Chun An, Chun-woo Lee","doi":"10.3796/KSFT.2012.48.1.029","DOIUrl":"https://doi.org/10.3796/KSFT.2012.48.1.029","url":null,"abstract":"Currently, environment-friendly and sustainable fisheries are one of the major issues among fisheries authorities. A variety of alternative management policies and projects are going on to enhance fisheries management systems and fishery resources such as a TAC management program and a VDS (Vessel Day Scheme) management scheme for distant water fishing nations in Western and Central Pacific Fisheries Commission (WCPFC) convention area. These kinds of efforts among fisheries management authorities are aimed at limiting fishing capacity or fishing power. In terms of fisheries management, Fishing capacity and fishing power have increased the importance of the impact on a fishery and level of the resources. Increased fishing capacity and fishing power have caused not only depletion of fisheries resource, but also additional fishing cost. therefore, there is a clear need for authorities to manage fishing capacity and fishing power. It is also help ensure the conservation and sustainability of the fishery resources. Because of lack of data, absolute fishing power is difficulty to measure. The notion of relative fishing power is frequently used. In this study, relative fishing power was assessed using Mastuda (1991) method for fishing power index. The raw data for assessment was based on fishermen`s logbook data from sampled fishing vessels in coastal snow crab gillnet fishery. Data Envelopment Analysis (DEA) method was used to assess fishing capacity. DEA is a linear programming methodology to measure the efficiency of a set of entities called Decision-Making Units (DMUs). It was recommended by FAO for assessing capacity in fisheries.","PeriodicalId":211073,"journal":{"name":"Bulletin of The Korean Society of Fisheries Technology","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133846532","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 : 2012-02-28DOI: 10.3796/KSFT.2012.48.1.001
S. Kim, Kyounghoon Lee, Hyung-seok Kim, Fisheries System
For the optimal design of a shrimp pot to control the catch size and to reduce catch the small size shrimp , tank experiments were carried out to study the pot stability under water . Tank experiments were carried out to measure the drag with 4 kinds of model pots that have 50% selection on the individual of 25 mm carapace length . The drag of each pot was measured every 10 times with changing the current speeds from 0.1 m/s to 0.7 m/s in 0.1 m/s intervals and the pot attack angle from 0。to 90 。in 15 。interval in a flume tank . The relation between the current speed and drag was presented . The stability of pot was estimated using the drag data and the friction data of Kim et al . (2008 b). The results showed that , the drag was shown lower as small as the projected area of pot depending on the current speeds and angles . The model pots were showed to slide on the seabed in case of rock at the current speeds 0.35 -0.38 m/s and the possibility of turn over at the current speeds 0.77 -0.89 m/s. In conclusion , the stability of a shrimp pot showed more stable as the pot of the lower the height and the smaller projected area on current .
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