• 선박안전
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• 통권21호
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• pp.51-65
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• 2006

The aim of this study is to supply the basic field data and precautionary measures that was obtained from analys of troubles and failures in the main engine and its accessories of fishing vessels. In this paper, we analyzed the accidents of main engines and their accessories in fishing vessels for five years from 2000 to 2004, according to engine system, type of fishing vessels and engine power. Finally, we propose the methods to reduces the accidents of main engines and rheir accessories in fishing vessels.

• Journal of Advanced Marine Engineering and Technology
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• 제40권7호
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• pp.574-579
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• 2016

기존의 연구에서 저항 성능을 정도 높게 추정하던 격자 시스템은 모형선의 길이 6-8m, 동적 트림 ${\pm}1^{\circ}$ 이하인 일반 대형 상선에 최적화되어 있다. 이러한 격자 시스템을 소형 어선과 같이 프루드 수 0.3~0.8, 동적 트림이 ${\pm}3^{\circ}$ 이상인 대상선에 적용할 경우 수치적 불안정성을 야기한다. 본 연구에서는 이러한 문제를 해결하기 위해 부심으로부터 입구 경계 조건의 길이를 줄이고, 자유수면의 각도에 따라 밀집된 격자 형태를 갖는 격자 시스템을 구성하였다. 상기 격자 시스템을 이용하여 설계 흘수와 밸러스트 흘수에서 다양한 선속에 대해 어선에 작용하는 저항을 수치 해석으로 계산하였으며, ITTC-1978 2차원 해석법을 이용하여 소형 어선의 유효마력을 추정하였다. 준추진효율 계수는 기존의 모형시험 자료를 활용하였으며, 설계 흘수에서 제동마력 추정을 통해 속도 성능을 평가하였다.

• 한국수산과학회지
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• 제41권6호
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• pp.485-492
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• 2008

To propose proper vessel characteristics for sustainable fisheries in Korean waters, we analyzed the fishing capacity, scale efficiency and utilization of large pair-trawl vessels based on the database of catch, effort and vessel characteristics (gross tonnage and engine power) in 1990 by applying data envelopment analysis (DEA). The input factors were gross tonnage, horse power and days operated; whereas the output factor was expected catch by vessel characteristics. The optimal vessel types, selected based on the input-oriented technical efficiency and gross tonnages, was 100 GT with engine power <600 HP. The output-oriented unbiased estimate of capacity utilization (CD) decreased with increasing vessel tonnage. For the same tonnage vessels, the CD decreased with increasing engine power.

• Ocean and Polar Research
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• 제28권4호
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• pp.439-449
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• 2006

This study was aimed at measuring the fishing capacity of Powered Anchovy Drag Net Fisheries (PADNF) in Korea using Peak-to-Peak(PTP) and Data Envelopment Analysis(DEA) methods recommended by FAO. In the analysis, both fishing capacities of total PADNF and individual PADNF vessels were measured with time series data and cross sectional data, respectively. In addition, the results of the DEA measurement were analyzed in order to determine reduction levels of fishing capacity. In case of total PADNF, the results by rn and DEA methods showed a similar rate of capacity utilization (79%), indicating the capacity was not utilized enough. In addition, the sensitivity analysis suggested that the number of vessels should be reduced by 20%, and the gross tonnage and the horse power should be reduced by 20% and 21%, respectively if the current catch is to stay at the 2004 level. The DEA results on individual PADNF vessels indicated the capacity utilization was 75% on average, showing some differences in capacity utilization among vessels (31%-100%). The results of the study would be useful for measuring production efficiency in PADNF. They would also provide good policy information for efficient use of resources and capacity reduction levels, which are useful far vessel buyback programs of coastal and offshore fisheries.

• 수산해양기술연구
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• 제59권1호
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• pp.74-84
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• 2023

This paper is the result of a comparative analysis of crew members' workloads using the EMG and OWAS methods according to the fishing process before and after the improvement of the operating system of the experimental vessel, with the aim of improving operational efficiency and safety work of coastal improved stow net fishing vessels. The target crew members were three people with at least five years of experience on board the same fishing vessel as the experimental vessel. After improving the operating system, such as installing a power block crane and two capstans, change the location of the ball-roller, the time required for setting and hauling work decreased (p < .01), and the evaluation results by OWAS showed that the overall workload for setting and hauling net work decreased. The results of muscle activity analysis showed a decrease in lashing anchor work (p < .01) in the case of hauling net and in anchor dropping work in the case of setting net (p < .001). It is judged that the use of ball rollers in net handling has been reduced; consequently, work safety has been improved.

• 한국수산과학회지
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• 제54권6호
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• pp.1030-1035
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• 2021

Diving fishermen are demanding permission to use an inspirator that can efficiently catch Manila clam; however, coastal fishermenargue that the use of inspirator devastates the seabed and depletes fishery resources. Therefore, the aim of this study was to evaluate the fishing power of diving gears and its effect on coastal fishing grounds. The average time taken to fish in the seabed (4 m²) with a rake, water gun, and an inspirator was 11.17 min, 13.33 min and 7.81 min, respectivelyThe values of catch per unit time with a rake, water gun, and an inspirator were 3.35 kg/min, 2.26 kg/min, and 3.83 kg/min, respectively. Suspended sediments were observed the most in the water gun fishing area, and were observed more in April when fishing was not carried out than in February when fishing was carried out. However, the difference in the amount of sediment deposited in the fishing area using the three-fishing gears was very small. For an accurate analysis of the impact of the fishing gears on the seabed, supplementary tests such as grain size analysis and changes in benthic organisms need to be conducted.

• 한국수산과학회지
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• 제41권6호
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• pp.511-517
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• 2008

The radiation characteristics and economic efficiency of high - luminance light - emitting diodes (LEDs), a metal halide lamp, and a halogen lamp were studied to evaluate their potential as an energy-saving light source for fishing lamps. The wavelengths at which irradiance was maximum were 709, 613, 473, 501, 525, 465, 578, and 973 nm for red, orange, blue, peacock blue, green, and white LEDs, the metal halide lamp, and the halogen lamp, respectively. If the irradiance characteristics at 300-1,100 nm wavelengths are set as 100%, the irradiance rates at 381-780 nm were 99-78%, 82%, and 24% for the LEDs, metal halide lamp, and halogen lamp, respectively. The economic efficiency was superior in the order metal halide lamp, halogen lamp, peacock blue LED, and blue LED at 381-780 nm and metal halide lamp, peacock blue LED, blue LED, and halogen lamp at 480-520 nm. Based on the radiation characteristics and economic efficiency evaluated at 480-520 nm, the blue and peacock blue LED light sources can be used as energy-saving light sources for fishing lamps.

• 대한조선학회논문집
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• 제46권2호
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• pp.127-135
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• 2009

The performance of the waterjet system of 180 ton class fishing guard ship has been experimentally studied. A waterjet propulsion system has many advantages in comparison with a conventional screw propeller especially for high speed craft because of its good cavitation performance. Recently waterjet system has been applied to fishing boats and fishing guard ship because of avoiding a net problem although their speeds are not so high. This paper describes experimental procedure and analysis method of resistance and self-propulsion tests with a 1/14.46-scale model. Experimental results were analyzed according to ITTC 96 standard method. The full-scale effective power and delivered power of the ship were also analyzed and the full-scale speed predicted from the model test results shows a good agreement with the full-scale result from the sea trial tests.

• International Journal of Naval Architecture and Ocean Engineering
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• 제13권1호
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• pp.858-876
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• 2021

Although widely used, the design of the bulbous bow for ships has been difficult due to the complex interference between the wave system generated by the bulb and the wave system of the ship hull. Until now, a bulbous bow has been often designed using Kracht charts, which were established based on model test data, but these charts apply only to ships with a block coefficient C_B = 0.56-0.82, Froude number Fn = 0.20-0.40, and the obtained bulb sizes are only close to optimal. This paper presents a new method for the optimal design of bulbous bow, starting from the design of an initial bulb using Kracht charts for ships with any block coefficient or Froude number, then resizing this initial bulb to define the optimal bulb sizes based on a multi-objective function of the required power reduction, and a combined solution of Computation Fluid Dynamics (CFD) analysis and surrogate models. This study was applied to a fishing vessel FAO 75, which has been model tested and used to design steel fishing vessels in Vietnam recently. The obtained quantitative results showed the same trend as the theory and practice, with a reduction of the ship's required power by about 14%.

• 수산해양기술연구
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• 제46권4호
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• pp.292-301
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• 2010

For an effective management of fisheries resources, it is very important that to make clean inhabitation environment and to preserve fisheries resources. The material which is mainly used as fishing gear in modern times, is polyethylene, polypropylene, polyamide, etc., chemical fiber. And lost fishing gears which are make of these, occur ghost fishing and ocean pollution. To solve these problem, we development biodegradable fishing trap using the polybutylene succinate (PBS). Developed traps are for red snow crab (Chionoecetes japonicus) and shrimp, major traps in the East Sea, and we carried out fishing research using two kind traps in the coastal sea of Ayajin-port (Goseong) to analysis fishing efficiency of PE trap and PBS trap. As a result for fishing experiment (year 2005-2006) of red snow crab trap, two kind traps were almost the same in catches and length composition. During a experiment, parts of meshes, used for over 1 year, were cut by biodegradation. As a result for fishing experiment (year 2007) of shrimp trap, northern shrimp (Pandalus eous), coonstripe shrimp (Pandalus hypsinotus) and morotoge shrimp (Pandalopsis japonica) were catched, and the almost is northern shrimp. Two kind traps were almost the same in catches and length composition. In accordance with these result, it is recommended that the developed traps are have to commercialized because the fishing powers of PE traps and PBS traps were same. But biodegradation speed is have to controled in consideration of ocean microorganism volume and traps life.