• 제목/요약/키워드: Fishing Characteristics

검색결과 522건 처리시간 0.021초

기후변화에 대한 어업인 인식의 특성 분석 (An Analysis of Fishermen's Perception to Climate Change in Korea)

  • 김봉태;이상건;정명생
    • 수산경영론집
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    • 제45권3호
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    • pp.71-84
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    • 2014
  • This study indicates that 84.5% of fishermen have perceived climate change and 74.9% of fishermen have responded that frequency and intensity of the impacts of climate change are increasing. The results of regression analysis have shown that the level of fishermen experiencing the impacts of climate change differs according to individual's characteristics including age, length of experience, sea area (fishing area) and types of fisheries. About half of the respondents have shown that they are not taking any actions against the effects of climate change. The main reasons are that they either have lack of knowledge on how to respond to the impacts of climate change or have the perception that climate change is irresistible. The majority of respondents have responded that they are not aware of the government's climate change policy and emphasized that it is necessary to have effective countermeasures strengthening the provision of information about climate change policy. The result of perception survey have highlighted that it is essential for the government and the fishermen to share relevant information and to consider method of cooperation.

유리섬유 보강재의 적층구성, 제작공법과 수지종류에 따른 구조강도 특성에 관한 연구 (A Study of the Mechanical Properties of Fiberglass Reinforcements with Constitution of Lay-up, Manufacturing Method, and Resins)

  • 송하철;염재선
    • 한국해양공학회지
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    • 제24권5호
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    • pp.75-80
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    • 2010
  • Fiberglass-Reinforced Plastic (FRP) composites have been used for small fishing boats and leisure boats for many years. These composites have different physical characteristics, depending on the constitution of lay-up and manufacturing method. Recently, new manufacturing methods, such as vacuum infusion, have been used to make the composites lighter and stronger. In this research, the mechanical properties of fiberglass reinforcements with constitution of lay-up, manufacturing method, and two different resins were investigated experimentally. It was found that the mechanical properties of FRP composites increased with increasing thickness, with the use of vacuum infusion method, and with the use of vinyl ester resin. The mechanical properties of diverse FRP composites can be used as a practical guide for selecting appropriate materials for specific applications.

조석(潮汐)의 영향(影響)이 있는 연안(沿岸)해역(海域)에서의 해안과정(海岸過程)의 변화(變化) (The Change of Beach Processes at the Coastal Zone with the Impact of Tide)

  • 김상호;이중우
    • 한국해양공학회:학술대회논문집
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    • 한국해양공학회 2002년도 춘계학술대회 논문집
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    • pp.257-262
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    • 2002
  • Numerical model introduced in this study combines wave refraction-diffraction, breaking, bottom friction, lateral mixing, and critical shear stress and three sub-models for simulating waves, currents, and bottom change were briefly discussed. Simulations of beach processes and harbor sedimentation were also described at the coast neighboring Bangpo Harbor, Anmyundo, Chungnam, where the area has suffered from accumulation of drifting sand in a small fishing harbor with a wide tidal range. We also made model test for the case of a narrow tidal range at Nakdong river's estuary area to understand the effect of water level variation on the littoral drift. Simulations are conducted in terms of incident wave direction and tidal level. Characteristics of wave transformation, nearshore current, sediment transport, and bottom change are shown and analyzed. We found from the simulation that the tidal level impact to the sediment transport is very important and we should apply the numerical model with different water level to analyze sediment transport mechanism correctly. Although the model study gave reasonable description of beach processes and harbor sedimentation mechanism, it is necessary to collect lots of field observation data, including waves, tides and bottom materials, etc. for better prediction.

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SPH Modeling of Hydraulics and Erosion of HPTRM Levee

  • Li, Lin;Rao, Xin;Amini, Farshad;Tang, Hongwu
    • Journal of Advanced Research in Ocean Engineering
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    • 제1권1호
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    • pp.1-13
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    • 2015
  • Post-Katrina investigations revealed that most earthen levee damage occurred on the levee crest and landward-side slope as a result of either wave overtopping, storm surge overflow, or a combination of both. In this paper, combined wave overtopping and storm surge overflow of a levee embankment strengthened with high performance turf reinforcement mat (HPTRM) system was studied in a purely Lagrangian and meshless approach, two-dimensional smoothed particle hydrodynamics (SPH) model. After the SPH model is calibrated with full-scale overtopping test results, the overtopping discharge, flow thickness, flow velocity, average overtopping velocity, shear stress, and soil erosion rate are calculated. New equations are developed for average overtopping discharge. The shear stresses on landward-side slope are calculated and the characteristics of soil loss are given. Equations are also provided to estimate soil loss rate. The range of the application of these equations is discussed.

A Study on Diesel Engine NOx and Soot Emission Characteristics using Different Fuel Oils

  • Nam, Jeong-Gil;Kang, Dae-Sun
    • Journal of Advanced Marine Engineering and Technology
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    • 제32권7호
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    • pp.1080-1088
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    • 2008
  • This paper addresses some concerns faced by the shipping industry nowadays. Initially, the environmental issues were resolved and stricter regulations are now being implemented with regards to the exhaust gas, specifically nitrogen oxides (NOx) and sulfur oxides (SOx), emitted from ships. Secondly, with the increasing and unstable cost of fuel oils in the world market, it has become almost a necessity to explore on a new alternative fuel. Hence, this study was conducted. An experiment was carried-out on a fishing survey vessel with the main engine (M/E) and generator engine (G/E) operated on expensive marine gas oil (MGO). During the experiment, two pre-refinery systems were installed and different fuel oil samples were employed for the M/E and the G/E. Furthermore, the NOx emission and soot concentration were monitored and verified. The results confirmed the compatibility of some fuel oil types to the engines and meeting the emission standards. MDO, MF15 and Bunker A can be used in place of MGO for the engines(M/E, G/E).

여수 연안 승망 어장에서 어획된 어업생물의 계절별 분포특성 (Seasonal distribution characteristics of fishery creatures caught in funnel net fishing ground of the Yeosu coastal sea)

  • 주찬순;박진형;박주삼
    • 수산해양기술연구
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    • 제42권3호
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    • pp.158-168
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    • 2006
  • A study on the species composition and seasonal variations of fishery creatures caught by a funnel net was carried out in the coastal water off Dolsan Island, Yeosu from 2002 to 2003. During the study period, a total of 23 fishery creatures species were caught. Seabream(Acanthopagrus schlegeli), sea bass(Lateolabrax japonicus), mullet(Mugil cephalus), puffer(Takifugu niphobles) and rockfish(Sebastes inermis) predominated. These five species accounted for 85.1% of the total number of fishery creatures caught. Seasonal peaks of number of species occurred in summer, while those of number of individuals occurred in autumn. The lowest number of species and individuals were observed in winter. The large annual variation of diversity indices were observed from May to August. These large annual variation of diversity indices were mainly due to predominance of seabream, sea bass and mullet which accounted for most of all fishery creatures caught. The seasonal variations of fishery creatures showed that sea bass and mullet were caught mainly from spring to summer, seabream and puffer were caught mainly in autumn, and rockfish and brotula(Hoplobrotula armata) were caught mainly in winter.

생분해성 청어 (Clupea pallasii) 자망의 어획성능 (Catching efficiency of the biodegradable gill net for Pacific herring (Clupea pallasii))

  • 안희춘;김성훈;임지현;배재현
    • 수산해양기술연구
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    • 제49권4호
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    • pp.341-351
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    • 2013
  • Physical characteristics of PA (Polyamide) gill net and biodegradable gill net made by PBS (Polybutylene succinate) (mesh size 63mm, mesh thickness number 2, 2.5, 3) were analyzed to investigate catching efficiency of the biodegradable gill net for Pacific herring. Total 11 numbers of catching efficiency tests were carried out using commercial fishing vessel at Imwon port in Kangwon province from May to June 2013. The amount of catches were 1,535.7kg (18 species) through the catching efficiency tests and it is expected that the practicalization of biodegradable gillnet is possible because there is no difference for catches between PA gillnet and PBS gillnet. Catches of herring according to the thickness of net twine was the highest at No.2 and the thicker net twine tends to decrease the catches.

한국연안해역에서의 효과적인 유류오염방제 모델에 관한 연구 (On the Effective Oil Spill Response Model along the Coastal Waters in Korea - Evaluation of the Regional Response Capabilities at the Port of Ulsan -)

  • Yun, Jong-Hwui
    • 해양환경안전학회지
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    • 제5권2호
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    • pp.1-14
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    • 1999
  • To find characteristics and areas of greater risk of oil spill at the coastal waters in Korea, some of risk factors were analyzed with historical data of oil spill and marine traffic. As a result, it is characterized that frequency of oil spill is increasing year by year and greatest percentage of spill source is fishing boat. It is proposed that the ports of Ulsan, Yeosu, Incheon and Pusan will be designated as primary area of risk as they have a higher risk of oil spills and its response authority is required to maintain appropriate regional response capability for prompt and effective response to a future spill incident. In addition, the regional response equipments at Ulsan are examined under a assumption of a medium size spill and it is found that the use of chemical dispersant can be an alternative when mechanical containment and recovery is not feasible in this area, and the existing response equipments may be appropriate to address that size of spill. However, the response authority is required to maintain more numbers of stronger boom for unsheltered waters and more quantity of concentrate dispersant to disperse all spilled oils on the water, furthermore the response authority should be prepared for a possible future catastrophic spill with sufficient equipments.

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댐호수의 특성별 휴양가치 분석 (Measuring Recreation Benefits of Dam Reservoirs in Korea - A Mixed Logit Approach -)

  • 권오상;김원희;이혜진;허정회;박두호
    • 자원ㆍ환경경제연구
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    • 제14권4호
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    • pp.867-891
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    • 2005
  • 댐건설 관련 합리적 의사결정을 위해서는 댐건설로 인해 발생하는 편익과 비용을 적절히 평가하여 비교하는 것이 필요하다. 댐건설 관련 많은 비시장적 편익과 비용이 현재로서는 의사결정에 적절히 반영되지 못하고 있는데, 본고는 비시장적 편익 가운데서도 댐이 건설될 경우 생성되는 인공호수가 제공하는 휴양가치를 분석한다. 방문객수가 많은 10개 댐호수에서 963명의 방문객을 조사하여 각 방문객이 이용 가능한 댐호수 가운데 한 군데를 선택하는 행위를 분석하였고, 이들의 선택행위를 혼합로짓모형(mixed logit model) 흑은 확률파라미터 로짓모형(random parameters logit model)을 추정하여 분석하였다. 모형추정을 통해 호수의 저수량, 낚시행위의 가능 여부, 유람선 이용 가능 여부, 수변 음식점이 이용 가능한지의 여부 등 댐호수의 특성별 경제적 가치와 호수별 전체 휴양가치의 분포를 도출하였다.

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패각의 소성 특성 및 지속성 담지체 제조에 관한 연구 (A study on the Calcination Characteristics and Supporter for Durability using waste shell such as Crassostrea gigas)

  • 김용렬;윤철훈
    • 한국응용과학기술학회지
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    • 제26권2호
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    • pp.143-150
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    • 2009
  • Today, wastes of much quantity by fast industrialization and increase in population, population concentration etc. of modem society are increasing. Much oyster shell is breeding by character and conduct of oyster-industry for a long time among them. Oyster shell which breed by-product in oyster cultivating industry that specific gravity of domestic seashore cultivating industry is high is causing environmental problem by problem and so on hindrance, nature spectacle's waste and health hygiene on administration if it is pollution of district along the coast fishing ground, number of public ownership being stored in open area in seashore. About new material just-in-time through recycling and he of oyster shell by these problem wide that study. Go forward more and investigate special quality that is oyster shell's physical chemistry red in this research and oyster shell oyster shell which cause several environmental problems developing ability agricultural chemicals that use this encapsulating micro by ability carrier that is environmentally application possibility examine wish to.