• Title/Summary/Keyword: Fishing operation

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Property of fish school and vertical temperature profile of Tuna Purse Seine in the Western Pacific Ocean (서부태평양해역에서의 다랑어 선망어업의 어군성상과 연직수온)

  • 김형석
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.35 no.3
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    • pp.237-241
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    • 1999
  • It was investigated that the condition of fishing ground gave what kind of effect school type in relation to the property for the target school after the vertical temperature profile and school type were observed when tuna purse seiner for tuna purse seine was operated in the western pacific Ocean around the equator between December 12, 1993 and January 26, 1994. The results are as follows;1. This study divided fish schools associated with drift objects, a one targeted-operation, and the pelagic migrating fish schools that are another one for the property. The total of 23 operations were complected including 6 that targeted fish schools associated with drift objects and 17 that targeted pelagic migrating fish schools. It was known that the main operation was conducted on pelagic migrating fish school.2. Average and standard deviation of the depth of the surface mixing layer was 86.0m and 13.8m for fish schools associated with drift objects. 61.6m and 13.0m for pelagic migrating fish schools, respectively. The average depth of the surface mixing layer of the pelagic migrating fish schools was lower when compared to the fish schools associated with drift objects however the concentration of standard deviation was higher than those fish schools associated with drifted objects. Accordingly, it was assumed that the effect of vertical temperature profile for pelagic migrating fish school was higher than the fish schools associated with drift objects.

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Principal Component Analysis on Marine Casualties (해난사고의 주성분분석)

  • Kim, Yeong-Sik;Yoon, Suck-Hun;Koh, Dae-Kwon
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.26 no.3
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    • pp.303-307
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    • 1990
  • In this paper, the factors of 1680 marine casualties occurred during 1986-1988 are analysed by the Principal Component Analysis. The main results are as follows: 1. Most of marine casualties result from the human factors such as careless operation and insufficient engine maintenance. Engine trouble is main part of accidents and great number of accidents is rated for fishing vessels. 2. Accidents are serious in case of cargo ships, passenger ships and tankers from the point of view of the damage of human life and properties. On the other hand, those are not so serious matter in case of fissing vessels and governmental vessels. 3. Grounding, collision and capsizal mainly result from careless operation, however material defect result in flooding

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A Study on the Efficient Operation of VTS in Inchon (인천항 VTS의 효율적인 운영방안에 관한 연구)

  • 김상환;박진수
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 1998.10b
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    • pp.11-25
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    • 1998
  • Many Countries have made efforts to assist ships navigate accurately , safely and expeditiously for the safety control against increasing marine traffic , in their coastal waters. However, they are exposed in spite of these efforts,to risks of casulaties and marine polluation caused by traffic congestion when ships are navigating through waterways approaches to ports or harbors and in narrow fairways. Therefore, efficient control of VTS in Port is necessary nowadays to provide ships with necessary service , which interacts with shipping and organize the flow of traffic so as to maximize the efficiency of the port or harbor while minimizing the risk of accident and environmental pollution. Even though the navigation condition of ships is very inferior compared to other ports in Korea, such as the big difference between the ebb and flood tide, the frequent fog, the narrow fairway , the density of navigation traffic in Inchon Port is high and transportation quantity of dangerous cargoe increases gradually. In cosideration of the characteristics of natural circumstance and traffic circumstance the VTS established newly in Inchon port have to operate efficiently. The purpose of this study is to help efficient operation of VTS in Inchon port by accomplishing both the literature research and questionnaire survey. Questionnaire survey was read to the VTS personnel in Inchon Port and customer familiar to Inchon Port such as ship navigators, pilots, shipping companies and so on. Most of ship navigators who occupy half of the respondents are Korean Officer who had responded while they were calling at Inchon port. The conclusions and recommendations includes ; First, the service area should be extended over Designated area to provide the vessel with navigational assistance service regarding the information of traffic congestion area, fishing boat and small ship's activities. Second, the types of information service to be offered are ship's movement and weather condition inthe vicinity of the port and state of fairway in the approaching channel to thte fairway. Third, VTS personnel should be upgraded by the on-the-job training and continuous simulation training as well as supplement of the qualified personnel for VTS operation. Fourth , the Harbor Master System to be introduced for safe navigation and efficient port operation.

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Comparison of catch rate by operation time of Korean tuna purse seine fishery in the Western and Central Pacific Ocean (중서부태평양 수역 우리나라 다랑어 선망어업의 시간대별 어획률 비교)

  • Young Shin, HA;Youjung, KWON;Mi Kyung, LEE;Sung Il, LEE
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.58 no.4
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    • pp.317-325
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    • 2022
  • Korean tuna purse seine fishery in the Western and Central Pacific Ocean (WCPO) began to operate in earnest in the early 1980s. Since then, the total catch has shown an increasing trend and the target species are skipjack tuna (Katsuwonus pelamis), yellowfin tuna (Thunnus albacare) and bigeye tuna (Thunnus obesus). Based on the operational data of Korean tuna purse seine fishery from 2016 to 2020, the catch rates of target species (skipjack and yellowfin tunas) were analyzed by operation time for set types (free school and FAD sets). In the case of the free school sets, they were usually made from sunrise to sunset, and the catch rate was high before and after sunrise for skipjack tuna and before sunset for yellowfin tuna. On the other hand, for the FAD sets, more than 90% of them were made just before sunrise, and there were few operations during the daytime. The purpose of this study is to examine whether there are differences in the catch rate of skipjack and yellowfin tunas by operation time and by school type for Korean tuna purse seine fishery in the WCPO, which could be helpful in understanding its fishing characteristics and providing useful information for developing the stock indices of the target species.

A proposal to build comprehensive maritime safety communication networks (해상 안전 종합통신망 구축 제안)

  • Yang, Gyu-Sik
    • Journal of Advanced Navigation Technology
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    • v.16 no.6
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    • pp.920-926
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    • 2012
  • In this paper, marine accidents recently happened in Korea and Japan for 5 years, especially through the analysis of accident characteristics for fishing vessels, including small vessels were analyzed. Also propose a new maritime safety communication network in the form of a comprehensive considering the wave propagation characteristics and operational characteristics of radio communication equipments should be installed in the vessel through comprehensive analysis of the regulation according to the radio equipment and the ship's location identification device installation and operation.

On the Total Length and Body Weight of the File File Fish , Navodos Modestus Caught in the Sonthern Sea Area of Komundo Is . During Summer (여름철 거문도 남부해역에서 어획된 말쥐치의 체장과 체중 조성)

  • 염말구
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.22 no.4
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    • pp.71-74
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    • 1986
  • The author tried to clarify the distribution of the total length and body weight of the file h, Navodos modcstus, caught by trawl net during July, 1984 in the southern sea korea. Among the catches of five times fishing operation, 1540 individuals were randomly sampled for the measurement. The results are summarized as follows; " The distribution of total length showed bimodal type, wbich was able to analyzed into two normal distributions N(17.46, 1. 02^2) and N(22.09, 1. 77^2). And smaller group was much than older one. The age of the sample estimated from the total length distribution of. smaller group was 1. 5 to 2, and the larger group 2. 5 to 4. The relationship between the total length and the body weight can be presented as following equation: $$W=0.01726 L^{2.8507}$$ ' or $$W= 0.01109 L^{3.0}$$ or $$W= 0.01109 L^{3.0}$$.

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A Analytic Study of Structural Factors in Saemanl Mini-Library (새마을문고의 구성요소에 대한 실태분석)

  • 전재봉
    • Journal of Korean Library and Information Science Society
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    • v.11
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    • pp.211-240
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    • 1984
  • The Saemaul Mini-Library system had to start as a purely voluntary grass-roots movement without a tax su n.0, pport. In other words, it had to depend on voluntary contributions in time and labor by the reading club members for its finance and daily maintenance and operation. The purpose of the study is to analyse the actual condition of a Saemaul Mini-Library, which is established in a rural and a fishing village. To meet this purpose, I will survey the function and the meaning of a Saemaul Mini-Library and the main tendency of it-now did it start and how did it develop and I will analyse the general condition of structural factors (establishment, materials, reading club) in a Saemaul Mini-Library.

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A Study on Automatic Separating System of the Sea Eel Pots from Main Line (통발 자동 분리기에 관한 연구)

  • Jung, Yong-Gil;Park, Young-Gil;Yoo, Keum-Bum
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.34 no.2
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    • pp.139-143
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    • 1998
  • In the fishing process on the sea eel pots, the most dangerous and difficult labor is manually separating process of several thousand pots from main line with high speed hauling operation. In this study, the automatic separating system of the pot from main line is developed. This system is composed with the clip connected to the pot by branch line, the keeper attached to the main line by pressing and the separator separating the clip and the keeper. In the experiment, static and dynamic characteristics of the system are investigated. From the considerations on the experimental results, it is ascertained that the automatic separating system of the pot from main line proposed in this study has good operating performance.

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Modelling of Swimming Ability Limits for Marine Fish

  • KIM Yong-Hae;WARDLE Clement S.
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.30 no.6
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    • pp.929-935
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    • 1997
  • The total energy of fish movement and the maximum burst swimming speed were estimated and formulated in accordance with body length and water temperature for several species in fisheries by empirical methods and also by using published results. Under the assumption of swimming energy reserve of a fish at the initial rest state, the swimming endurance of fish with different body lengths, swimming speeds and angular velocity was calculated using the relevant equations under similar conditions in tank experiments as well as natural conditions in field. Relative swimming energy efficiency or the transition swimming speed between red and white muscle for energy consumption was represented as a trigonometric function of swimming speed ratio. Therefore, this model does closely approach the actual swimming abilities and their limits especially in relation to the fishing gear operation and allow for the greater vitality of the wild fish in the fields.

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Optimization of Surface Roughness of STS 304 in a Turning Process (STS304합금의 선삭가공에서 표면거칠기의 최적화)

  • Choi, Man Sung
    • Journal of the Semiconductor & Display Technology
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    • v.16 no.1
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    • pp.59-64
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    • 2017
  • The general manufacturing problem can be described as the achievement of a predefined product quality with given equipment, cost and time constraints. Unfortunately, for some quality characteristics of a product such as surface roughness it is hard to ensure that these requirements will be met. Stainless steels STS 304 is frequently used as shaft materials in small fiber reinforced polymer(FRP) fishing boats. In this work, the dry turning parameters of STS 304 are optimized by using Taguchi method. The experiments were conducted at three different cutting speeds with three different feed and three different depth of cut. The cutting parameters are optimized using signal to noise ratio and the analysis of variance. The effects of cutting speed and feed on surface roughness was analyzed. The results revealed that the spindle speed is the more significant parameter influencing the surface roughness.

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