• Title/Summary/Keyword: fishing conditions

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Comparison of Mechanical Characteristics of Fiber-Reinforced Lightweight Soils (섬유보강 혼합경량토의 역학적 특성 비교)

  • Kim, Yun-Tae;Han, Woo-Jong
    • Journal of Ocean Engineering and Technology
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    • v.22 no.4
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    • pp.51-58
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    • 2008
  • The objective of this study was to investigate the mechanical characteristics of fiber-reinforced lightweight soil using waste fishing net or monofilament for recycling both dredged soils and bottom ash. Reinforced lightweight soil consists of dredged soil, cement, air foam, and bottom ash. Waste fishing net or monoiament was added the mixture in order to increase the shear strength of the lightweight soil. Test specimens were fabricated with various mixing conditions, including waste fishing net content and monofilament content. Several series of unconfined compression tests and direct shear tests were carried out. From the experimental results, it was found that the unconfined compressive strength, as well as the stress-strain behavior of reinforced lightweight soil was strongly influenced by mixing conditions. In this study, the maximum increase in shear strength was obtained with either a 0.5% content of monofilament or 0.25% waste fishing net. The unconfined compressive strength of reinforced lightweight soil with monofilament was greater than that of reinforced lightweight soil with waste fishing net.

Evaluating the Application Feasibility of Lithium-Battery Electric Propulsion for Fishing Boats

  • Haiyang Zhang;Jaewon Jang;Maydison;Daekyun Oh;Zhiqiang Han
    • Journal of the Society of Naval Architects of Korea
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    • v.60 no.3
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    • pp.175-185
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    • 2023
  • Many small vessels such as fishing boats operate in the world's oceans; accordingly, interest in these small vessels' exhaust-gas problem is increasing. Research on the application of electric-propulsion technology has been steadily conducted; however, the subject is limited to research ships or leisure boats, while research on application efficiency remains insufficient. This study attempts to apply lithium-battery electric-propulsion technology to small ships. A gross tonnage of 9.77, a representative fishing boat, is to be redesigned as a fully electrified ship. Without changing the main cabin's dimensions and fuel tanks, the ship's propulsion system is redesigned based on a lithium-battery electric-propulsion system. In addition, the redesigned system is compared with the original sample ship's diesel-propulsion system for application-effect analysis. The results indicate that under controlled sailing conditions, the weight and volume of the electric-propulsion system are 9.5 and 10.5 times those of the diesel-propulsion system, respectively. These values indicate that the system cannot meet fishing boats' high endurance requirements. Therefore, under the existing technical conditions, applying the full lithium-battery electric-propulsion system to solve the problem of high emissions from fishing boats shows limited feasibility.

A Study on Success Factors of Coastal Fisheries in Busan Region (부산시 연안 어선어업 경영체의 성공요인에 관한 연구)

  • KWON, Hyeok-Seung;SONG, Jung-Hun
    • The Journal of Fisheries Business Administration
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    • v.46 no.2
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    • pp.1-11
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    • 2015
  • Due to the environmental changes such as decreasing and aging fishing population and increasing imported marine products, improvement of fishing business competitiveness has become one of important issues. This study aimed to analyze the coastal fishing business units in Busan region and compare their business performances in order to find out success factors. The logistic regression analysis between 4 determination factors of competitiveness and business performances showed that the ship tonnage in the factor conditions, catch of species of fishing types'kg per price in the demand conditions, cooperative sales ratio in the related & supporting industries, and net per cost in the firm strategy, and structure & rivalry had the positive(+) impacts on business performances.

Stability Characteristics based on Crane Weight of Small Fishing Vessels Under Standard Loading Conditions: Investigation Report of the Capsize Accident at Goseong Port (크레인 교체에 따른 표준재화 상태에서의 소형 어선의 복원성 특성 - 고성항 전복 사고 재결서 중심 -)

  • Kang, Dae Kon;Lee, Gun Gyung;Lee, Jun Ho;Han, Seung Hun
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.26 no.1
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    • pp.22-30
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    • 2020
  • In March 2016, a 6.67-ton fishing boat capsized owing to the loss of stability during crane operations. Capsizing occurs when a boat or ship is flipped over (or turned upside down) for reason other than accidents caused by collisions, contact, stranding, fire or explosion. Over the past nine years (2010-2018), capsize accidents have accounted for 2.34 % of all marine accidents and are gradually increasing. The loss of stability from improper shipping is the main cause of most capsizes, especially for small fishing vessels weighing 10 tons. According to the Fishing Vessel Act, small fishing vessels weighing less than a ton are exempted from inspections on stability and load cranes. This study analyzes the issue cited as the reason for the capsizing of the small fishing boat in Goseong, namely, the reduction of restoring moment due to increased weight of the crane. Fishing boats with similar loading conditions were modeled on the basis of re-determination, and their stability before and after the accident was assumed. The fishing boats with heavier cranes were found to be at higher risk of capsizing owing to the reduction of the restoring moment and the angle of deck immersion. Under standard loading conditions, the stability moments of fishing vessels are lesser during fishing, compared to when they depart from or arrive at the port.

A Historical Consideration on the Evolution of Competition in Offshore Fisheries (근해저인망류어업에 있어서 업종별 경합관계 형성에 관한 사적고찰)

  • 김병호
    • The Journal of Fisheries Business Administration
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    • v.35 no.1
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    • pp.23-56
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    • 2004
  • The offshore trawl fishery is seeking its survival way to overcome current management conditions in red, resulted from the bilateral agreement with China and Japan. However, this movement magnifies conflicts between fisheries on the contrary and it is thought to be impossible to get over current situations. For all that, this study is aimed at investigating how this current situations have occurred. The management freedom as response to the change in fishing conditions of a certain fishery, in case of Korea, is affected by institutional regulations. The example of this is controls on fishing gears, fishing vessels, and fishing grounds. The most exposure of this control is a segmentation of institutional fisheries. The initial segmentation of the offshore trawl fishery in Korea was occurred in the period of Japan's colonization when the degree of use of fishing grounds was limited geographically. At that time, fisheries were divided by fishing areas, but it did not divide the fishery itself. The large - sized fishing vessels were developed politically to be more competative to Japanese fishing vessels since 1950s. During this time, the trawl fishery was merged into current Eastern trawl fishery and South - Western trawl fishery. It was also inevitable to divide into the pair trawl and single trawl fishery as a result of the physical mergency between Western trawl and Southern trawl fishery. In order to develop the trawl fishery, new licenses were issued on the shrimp trawl fishery, through which it was expected to boost the trawl fishery. As opposed, the shrimp trawl fishery was changed into the mid - sized trawl fishery, targeting on the eastern fishing areas and the large - sized trawl fishery was developed since the late of 1970s with the development of filefish processing industry. The large trawl fishery that led in development of offshore trawl fishery since the late of 1950s was started to divide into a pair trawl and single trawl according to the fishing method and capital power. It finally became an institutionally independent fishery in 1980s, respectively. Looking into these historical process, the segmentation of the trawl fishery is thought as a result of the lack of long - term perspective and as a production of trial and error resulted by unprepared policy. As a result, these segmentation of fisheries roles as critical obstacles in harmonization of fisheries and in overcoming of current situations. Therefore, the review of this institutional segmentation of the offshore trawl fishery should be taken for an optimal redistribution of fishing grounds suits with business and fishing technology. For this, the fishery must be divided into large capitalized fishery and small - mid fishery with consideration of capital, fishing method, and the condition of use of fishing grounds. In addition to this, by limiting outline of fishing ground that the large fishery can harvest, it must allow for the small - mid fishery to catch with its own boundary. Furthermore, by launching buyback programs on the trawl, eastern trawl, pair trawl, it can provide broader fishing grounds where the fishery can harvest with management freedom.

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The disposal process for scrapped FRP fishing vessels (감척으로 인한 FRP 어선의 처리방안)

  • Song, Jung-Hun
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.44 no.1
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    • pp.75-80
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    • 2008
  • A scrapped fiber-reinforced plastic(FRP) fishing vessel causes many environmental problems, because technology development for recycling FRP vessel has not been adequately addressed. FRP is a main material for constructing a small coastal fishing vessel that is an object of reduction policy. Therefore, the FRP wastes derived a scrapped fishing vessel are increasing. In this study, I investigated an effective disposal process for FRP through the analysis of the actual conditions of scrapped FRP fishing vessel. The treatment processes of scrapped FRP fishing vessel are carried out with oil-removing, dismantling, intermediated processing(crushing), and then reclaiming follows burning in the final processing in Korea. However, in Japan, several recycling methods have been developed, for example, the incineration including thermal recovery, the use of cement-reclamation, and the use of asphalt concrete aggregate, because the method of reclaiming after incinerating which is generally used in Korea produces a toxic by-product such as dioxin.

Analysis of Demands and Actual Status of Fishing Village People to Keep Young Fishermen for Fishery (젊은 어민인력 유치를 위한 어촌주민의 생활실태와 요구분석)

  • Lee, Kyung-June
    • Journal of Fisheries and Marine Sciences Education
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    • v.6 no.1
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    • pp.1-10
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    • 1994
  • This study attempted to investigate the demands of fishing village people and the actual status of their living, to diagnose the problems in fishing villages and to present some basic data for fishing village development. The major findings of this study were as follows ; 1) The problems in fishing village of Korea included fishing village, household debt, big fluctuation of fish prices, children's education, cultural and welfare facilities need to investment for equipment, marriage and health. 2) The respondents said that fishing village household debt was mainly caused by lack of income from fishery(37%), educational expenses(28.5%), excessive fishery expenses(20%), excessive fishery equipment(15%), and government policy(12%). 3) The outlook of fishery development is considered bright by the respondents. They said that fishery would be a prospective industry if the appropriate conditions are given. Considerable research efforts for government policies will be needed to develop the fishery industry.

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Schooling Behavior and Estimation of the Fish School in Set Net by Fish Finder (어군탐지기에 의한 정치망내의 어군의 행동과 어군량 추정)

  • 신형일
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.22 no.1
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    • pp.11-18
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    • 1986
  • Schooling behavier to a fishing gear and estimation of the volume of fish school in set net have ~ been studied by making use of such techniques as visual observations, underwater cameras, under- water televison. However, all of these observation techniques are subject to restrictions caused by illumination, underwater visibility, underwater transparent and sea conditions. For the above mentioned reasoa, one of the most effective method by this time become generally known a method using fish finder. In this paper, in order to control the fishing ground of set net effectively and to develope the telemetric fish finder, the experiments for the target strength, underwater shape of fishing gear, schooling behavier and volume of fish school with fish finder were performed at Galgott fishing ground of set net located Keouje Island, 15th-24th July and 18th-20th October in 1985. The results of these experiment showed that a method using fish finder in fishing grOlllld of set net is available for estimating distribution and school size, fish behavier in relation to a fishing gear and underwater shape of fishing gears.

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Analysis and Modeling of Fishing Boat's Power Network for using Renewable Energy Source (신재생 에너지원 활용을 위한 어선 전력계통 분석 및 모델링)

  • Lee, Sang-Jung;Lee, Dong-Gil;Jung, Jee-Hoon
    • The Transactions of the Korean Institute of Power Electronics
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    • v.21 no.2
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    • pp.182-189
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    • 2016
  • A modeling method of electric power network inside a fishing boat less than 5 tons is proposed for its high-energy efficiency with renewable energy sources. The power network inside the fishing boat consists of a diesel engine, a starter motor, an alternator, battery packs, and electric loads, which are connected in parallel. To obtain proper power network model, the voltage -current characteristics of the electric components are considered to develop elaborate electrical models under several load conditions. Measured data of the battery and alternator current include noise. By using an average method, the AC components from the power network of the fishing boat can be reduced, which is verified by KCL rule. Using the proposed power network model, the power generation of the alternator and the reduction of diesel consumption in the boat's engine are predictable under various operating conditions. The validity of the proposed methodology is verified by comparing simulation results with experimental measurements using statistical inferences.

The Effect of Person-Specific Factors on Coastal Vessel Fishing Catch in Korea (우리나라 연안어업생산에 있어서 인적요소의 영향분석)

  • 김기수;강용주
    • The Journal of Fisheries Business Administration
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    • v.30 no.2
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    • pp.79-89
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    • 1999
  • This study is conducted to apply the insight of Johnson and Libecap(1982) to Korea's coastal vessel fishing. According to Johnson and Libecap(1982) the differences in fishing ability are largely attributed to acquired knowledge and innate skills. Since those skills are unlikely to be readily transferable assets, economic rents exist in the fishery, even under open access conditions. Therefore the paper tries to examine whether the acquired information from fishing experience and innate skill could also have an effect on catch variation of coastal vessel fishing in Kyung-Nam province. To do so, the paper is performing the analysis by establishing econometric model. Results show us that the acquired information from fishing experience have a significant effect on catch variation, but the innate skill does not.

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