• Title/Summary/Keyword: Fishing condition

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Long-term variation in catch of Spanish mackerel (Scomberomorus niphonius) related to environmental change in Korean waters (환경변화에 따른 한국 연근해 삼치 (Scomberomorus niphonius) 어획량의 장기변동)

  • Lee, Seung-Jong;Kim, Byung-Yeob;Chang, Dae-Soo
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.47 no.2
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    • pp.99-107
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    • 2011
  • The relationships among long-term variation in catches of Spanish mackerel (Scomberomorus niphonius) and main food organism such as common mackerel (Scomber japonicus), anchovy (Engraulis japonicus), and oceanic condition in Korean waters were analyzed using 40 years of time-series data from 1971-2010. In the 1990s, oceanic conditions around the Korean peninsula shifted to a warmer regime with higher SST (sea surface temperature). The total catch of Spanish mackerel in Korean waters increased dramatically since the early 2000s, and main fishing ground form into South Sea in winter season from December to January. From the results of correlation analysis, we found a significant relationship between the Spanish mackerel catch and environmental factor such as SST, common mackerel and anchovy catch in Korean waters.

A Study on Transverse Stability of Ships in Following Seas (추파중에서 항행하는 선박의 복원성능에 관한 연구)

  • K.H.,Son;S.D.,Yun
    • Bulletin of the Society of Naval Architects of Korea
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    • v.26 no.1
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    • pp.1-10
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    • 1989
  • When a ship is travelling in following seas, the encounter frequency is reduced to be very low. n that case surf-riding, broaching-to and capsizing phenomena are most likely to occur. In the present paper, the emphasis is laid upon the transverse stability of ships in following seas, which is related to capsizing phenomenon. The authors intend to clarify the mechanism of the stability variation in following seas. In order to predict that variation, the theoretical calculation method and computer programming are developed. The theoretical calculation is based on Froude-Krylov Hypothesis and static equilibrium condition in waves. Through the application of present calculation method to cargo vessel and fishing boat, it is verified that the transverse stability in following seas with crest amidships can be reduced to a half extent in comparison with calm water stability. On the other hand, the present calculation results are compared with existing experimental data.

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A Study on the Estimation of Remaining Fisheries Damages Considering the Recovery Periods of Fisheries Resource after the Completion of Undertaking Yeongsan River Project (영산강 살리기 사업 이후의 자원회복기간을 고려한 잔존어업피해추정에 관한 연구)

  • Choo, Hyun-Gi;Jo, Mun-Kwan;Kim, Ki-Soo
    • The Journal of Fisheries Business Administration
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    • v.51 no.4
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    • pp.1-18
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    • 2020
  • The paper aims to explore existence and degree of remaining fisheries damages after the completion of undertaking the Four Major Rivers Project focusing on the case of Yeongsan river. The paper seeks to show the necessity of consideration of periods of fishery resources recovery in the estimation of ex-post fisheries damages of the project by inferring the analysis of the annual variation of environmental indicators in the river. Therefore, the paper suggests three years of remaining periods of fisheries damages of the project utilizing the variation trend of ex-ante and ex-post annual output data of inland fisheries in Jeonnam province and individual catch of fisheries. In the measurement of the annual degree of fisheries damages during periods of fishery resources recovery, the paper attempts to suggest the method of comparision of day catch data per vessel between ex-ante and ex-post periods of the project, which were investigated by the same institute. Here the paper tries to make correction of ex-post catch data for holding the same catching condition as ex-ante situation by adopting the concept of competitive intensity of catching which was derived from the decreasing rate of number of fishing households in the area of Yeongsan river.

An Analysis of Disposal Site about an Airport useing ICAO and GIS (ICAO 기준과 지리정보를 이용한 공항입지선정에 관한 연구)

  • Choi Hyun
    • Spatial Information Research
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    • v.13 no.3 s.34
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    • pp.323-333
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    • 2005
  • This paper shows disposal site about an airport using ICAO(International Civil Aviation Organization)and GIS(Geographic Information System). In Korea, mountains occupy above $70\%$ of the whole country centering around Baek-Du mountain range and a physical distribution system doesn't go on smoothly between east and west region. At present, disposal site about an airport follows the standard of ICAO and FAA(Federal Aviation Administration). So, it's desperately necessary to make the new standard suitable for the condition of Korea. This study analyzes major customers in the aerospace and transportation sector by considering the present condition of location of geography, atmospheric phenomena, population and transportation about Ul-Jin airport on the standard of ICAO and FAA. As the results, Gi-Sung site proposed for the airport using the existing a runway in air force has a locality road connecting a fishing and agrarian villages and is shown better than the others.

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Stability of the offshore large purseiner in Korea (한국 근해 대형 선망 어선의 복원성)

  • Ham, Sang-Jun;Kang, Il-Kwon;Kim, Hyung-Seok;Jo, Hyo-Jae;Kim, Jung-Chang
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.47 no.3
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    • pp.241-247
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    • 2011
  • Marine casualties of vessel are said to be in most case caused by human error, but it would be valid for the assumption that the ship is built with high quality and then should be acceptable to the safety standards. It means that the inherent characteristics of a ship should be the first consideration on the safety of ship. Therefore it is basically necessary for navigator to grasp the inherent stability of his ship and ensure that the ship complies with the minimum statutory standards of stability. This study is to realize the stability of the Korean offshore large purseiner varying with loading conditions by the inclining data and some calculations. The author compared the stability of the ship with IMO criteria and domestic rule, and proposed some improvement for the safety of the ship. The results are summarized as follows ; The values of GM of the ship according to the loading condition in navigation satisfy both of the IMO criteria and the domestic rule, but in case of the area under the GZ curves between the heel angles of $30^{\circ}$ and $40^{\circ}$, and the heel angle occuring the maximum righting lever not satisfy the IMO rule at the fishing ground departure and arrival conditions in the haul in net situation. The initial metacentric height of the ship is very large, but the range of stability and the occurring angle of the maximum GZ are very small, so even small inclining can bring about the beam end. The best method of improvement for that is to increase the freeboard of the model among the variables.

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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A Study on the Characteristic and Types of Spatio-functional Differentiation by Industrial Structure in Korean Island Areas (읍·면급 섬지역의 산업구조에 의한 공간기능 분화 유형별 특성)

  • Cho, Eun Jung;Choi, Soo Myoung;Park, Yong Jin
    • Journal of Korean Society of Rural Planning
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    • v.21 no.1
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    • pp.129-141
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    • 2015
  • This study classifies the types of spatio-functional differentiation in Korean island areas and analyses typical characters and suggests the development directions by each type. Eup/Myeon-level island areas are classified as six types by the factor analysis and the cluster analysis. First type is the traditional rural center. This type puts emphasis on maintaining phase as the central space and has to maximize development potential of the whole of settlement zone. Second type is the specialized region in manufacturing industry and the qualitative mutual growth of regional industries is able to be suggested. Third type is the specialized region in the neighborhood service provision. This type needs to devise the plan for utilizing potential customers actively and developing into the region specialized in tourism industry. Fourth type is the specialized region in tourism-support service functions. This type has to promote differentiated policies for maintaining amenity infra or value of countryside capital and preservation and utilization of resources by regional features. Fifth type is the fishing industry-dominated region. This type has to promote sustainable fishery development through the policy reflecting regional features and condition. Finally, sixth type is the sluggish region dominated with the traditional agriculture and fishery. This type is needed to aim at developing into the new food production base having the advantage of clean environment by strengthening support in specialized agro-fishery products. The existing researches on spatio-functional differentiation were mostly discussed with respect to land development, but this study highlights the difference in deal with the island areas distinguished from the condition of industry.

A Study on Reform Directions for Promotion of Fishermen's Labor Condition (어선선원(漁船船員)의 노동조건(勤勞條件) 개선방안(改善方案)에 관한 연구(硏究))

  • Lee, Zong-Keun;Im, Dnog-Cheul
    • Journal of Fisheries and Marine Sciences Education
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    • v.5 no.1
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    • pp.23-30
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    • 1993
  • The Korea Seaman's Act is providing that fishermen s salaries are exceptionally defined and working hours and paid leave are not defined at all. Significant problems of Fishermen's Labor Condition are, (1) It is hard to guarantee the basic right of fishermen as their wages are variable depending on the catch. (2) Excessive working hours would hamper the labor reproduction ability and increase the frequency of disaster. (3) Moreover, fishermen have to search for a new job following the lay off after working aboard during the period defined by contract. The possible implement of Seamen's Act are : (1) The wage system must be unified by regular wages. If it is hard to perish the lay system its relative importance should be diminished whereas the fixed minimum wages and the allowance depending on the position and working days should be paid. (2) This discrimination of the fishing vessels from merchant should be eliminated by removing the item on the Act which excludes the fishermen on the working hours. If it is hard to do so practically the lower regulations defining the maximum periods of duty and minimum periods of rest for fishermen must enact separately as in Japan and England. (3) The difference in the provisions of paid leave between the merchant seamen and fishermen must be abolished (4) It is the most desirable to improve the fishermen's labor conditions through the completion of the Act. However, before doing this, the employers and employees must try to solve the problems through the collective agreement by themselves.

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Effect of flagpole attached to buoy on tension of buoy rope of gillnet (자망어구 부이의 깃대가 부이줄 장력에 미치는 영향)

  • CHO, Sam-Kwang;LEE, Gun-Ho;CHA, Bong-Jin;JUNG, Seong-Jae;KIM, In-Ok
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.52 no.4
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    • pp.290-298
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    • 2016
  • This study aims to reduce the force exerted to the buoy of the gillnet by wave and current. Five buoy models were selected for experiments and their rope tensions under wave and current action were compared. Five models were EL (ellipsoid), EL-H (ellipsoid-hole), SL (streamlined body), SP (sphere) and CL (cylinder, traditional type). In the first experiment, the Five models were tested without any attachment. In the second experiment, a flagpole was attached to each model. As a result, in the condition without flagpole, the tensions of four models with the exception of the CL were about a half of that of the CL. In the condition with flagpole, the tension of all models was twice larger than that without flagpole. Thus, a new model was suggested to improve the problem, which has a combined body that of a flagpole and a buoy Three new models of CL-L (long and thin cylinder), LF (leaf shape) and LF-F (leaf shape with fin) were designed. Also a cylinder type (CLD) with a flagpole as a control was included in the experiment. As a result, the LF-F had the smallest tension and a half tension of the CLD. Therefore, it is supposed that the flagpole and buoy combined model could reduce the tension on buoy rope and contribute to improve the gillnet loss problem.

Difference of tension on mooring line by buoy type (부이 형상에 따른 부이줄 장력의 차이)

  • Lee, Gun-Ho;Kim, In-Ok;Cha, Bong-Jin;Jung, Seong-Jae
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.50 no.3
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    • pp.233-243
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    • 2014
  • The difference of mooring tension by type of buoy was investigated in the circulating water channel and the wave tank for deducting the most stable buoy from the current and the wave condition. 5 types of buoy made up of short cylinder laid vertically (CL-V), short cylinder laid horizontally (CL-H), capsule (CS), sphere (SP) and long cylinder (CL-L) were used for experiments. A mooring line and a weight were connected with each buoy. A tensile gauge was installed between a mooring line and a weight. All buoy's mooring tension was measured at the same time for the wave test with periods of 1.5~3.0 sec and wave heights of 0.1~0.3 m, and the current test with flow speeds of 0.2~1.0 m/sec. As a result, the order of tension value in the wave test was CL-H > CL-V > SP > CS > CL-L. In the current test CL-V and CL-H were recorded in the largest tension value, whereas SP has the smallest tension value. So it seems that SP buoy is the most effective in the location affected by fast current. CS is predicted to be suitable for a location that influence of wave is important more than that of current if practical use in the field is considered. And it was found that the difference of mooring tension among buoys in wave is related to the product of the cross sectional area and the drag coefficient for the buoy's bottom side in high wave height. The factor for the current condition was not found. But it was supposed to be related to complex factors like a dimension and a shape by buoy's posture to flow.