• 제목/요약/키워드: Otter

검색결과 147건 처리시간 0.02초

새바다호에서 사용하는 트로올그물의 유체저항에 관하여 (Hydrodynamic Resistance of Some Trawl Nets Being Used by M/S Saebada)

  • 김진건
    • 한국수산과학회지
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    • 제17권1호
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    • pp.1-8
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    • 1984
  • 어구의 전저항에서 전개판과 끌줄의 항력을 뺀 나머지를 트로올 그물의 유체저항이라 보고, 그물의 유체저항과 연계상의 요소 및 예망속도와의 관계를 R_N=k\frac{d}{l}abv^n 라고 표현할때, 새바다호에서 사용하고 있는 각종 그물에 대한 k와 n의 값을 구한 결과는 다음과 같다. 1. 6폭짜리 그물에 2가닥의 그물목줄을 쓰는 형(A형)과 8폭짜리 그물에 3가닥의 그물목줄을 쓰는 형(B형)은 예망속도가 1.8m/sec 이상일때 k는 11, n는 1.8이었다. 2. 10폭짜리 그물에 3가닥의 그물목줄을 쓰는 형(C형)은 예망속도가 1.8m/sec이하일 때는 k는 12, n는 1.3이며, 예망속도가 1.8m,/sec 이상일 때 k는9, n는 1.9이였다. 3. 10폭짜리 그물에 4가닥의 그물목줄을 쓰는 형(D형)은 예망속도가 1.8m/sec 이하일 때는 k는 16, n는 1.0이고, 예망속도가 1.8m/sec 이상일 때는 k는9, n는 1.9이었다.

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방조제 건설 중인 2001-2002년 새만금 하구역 어류 종조성의 계절 변동 (Seasonal Variation in Species Composition of Fish in the Estuary of Saemangeum Waters during the Construction of a Dike in 2001-2002)

  • 이태원;문형태;김광천
    • 한국수산과학회지
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    • 제36권3호
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    • pp.298-305
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    • 2003
  • Seasonal variation in species composition of fish in the estuary of Saemangeum water in the western coast of Korea was determined using seasonal samples collected by an otter trawl from April 2001 to February 2002. Species compositions did not differ significantly among the 4 stations (p>0.05, Wilcoxon signed-rank test). The cumulative number of species and species diversity (H') approached asymptote after four 30-min trawl hauls. Therefore 30-min trawl samples from each of the four stations were pooled to represent each season. A total of 45 species 2758 individuals and 30,346.8 g of fish were collected during the study period. Of the fish collected Leiognathus nuchalis, Synechogobius hasta, Neosalanx jordani, Konosirus punctatus and Chaeturichthys stigmatias predominated in abundance accounting for $68\%$ of the total number of individuals. Seasonal variation of fish abundance showed a similar trend to those of the other western coastal waters of Korea. The resident species were collected only in spring and autumn. Number of species and biomass were highest in summer due to the catch of many migrating species. In winter catch amount was low, and only 7 species were collected.. Brackish water fishes were more abundant in the study area, and Johnius grypotus and Cynoglossus joyneri were not premominated compared to the other coastal waters. This difference in species compositions may be related to the lower salinity in this estuarine habitat than in the other western coastal waters of Korea.

북태평양(北太平洋) 중층(中層)트롤그물의 발달(發達) (The Development of Midwater Trawl Net in North Pacific Ocean)

  • 권병국;장호영
    • 수산해양교육연구
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    • 제6권1호
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    • pp.11-19
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    • 1994
  • The North Pacific midwater trawling which is one of the important fishing methods for Korean fishing industry is working in the Bering Sea and the sea near Kamchaka Peninsula. The catch by Korean midwater trawlers had been recorded about 300 thousands $^{M/_T}$ a year. Six types of midwater trawl net-ordinary midwater trawl net, super-V trawl net, super mesh trawl net, rope trawl net, super plus trawl net and kite trawl net-have been widely used by large trawlers above 1,500gt in size since 1982. Regarding the fishing efficiency, the super plus trawl net and kite trawl net were acknowledged as higher than other nets. Maximum mesh size of super-plus trawl net and kite trawl net ranges about 20m, whereas the length of net about 150m, and high-tech polyethylene is used as the material of rope part. The problems involved in the North Pacific midwater trawl net may be summarized as follows ; (1) The dimension of fishing gear is too big compared with the towing power of trawler. (2) The mesh size of the rope part is too big compared with that of the common netting part. (3) The net is often torn out in the connecting position of the rope part and the netting part. (4) The net is not matched with the trawler and the otter board in many trawlers, so the shape of the trawl gear in the water is instable. (5) The fish school located near head rope, ground rope and side rope in the net recorder is not caught in practice because of the net instability.

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친환경적 설계인자를 적용한 생태복원공사의 시공성 평가 - 거제시 구천천 생태하천 조성공사를 중심으로 - (The Constructability Evaluation of Ecological Restoration Construction Using Environment-friendly Design Factor - In the case of Construction of Gucheon Eco-River in Geoge City -)

  • 안병철
    • 한국환경복원기술학회지
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    • 제16권4호
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    • pp.99-114
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    • 2013
  • In this study, constructability of ecologocal stream restoration process was evaluated and improved approaches for habitat were suggested. The study site is Gucheon River in Geoje city where conducted ecologocal restoration work within maintaining its flood control function. Application of ecological design factors and constructability in the process from planning to construction was analyzed and its results are as follows: In the process of planning and designing, it was focused more on the naturality of Gucheon River rather than the human convinience and ecological design factors were applied within the ecological capacity of the site. First, the indexes for constructability evaluation is selected. It was classified into three major categories as construction quality, design quality and construction administration system. Each index has details, so there are twenty sub indexes for contractibility evaluation. Second, the evaluation results shows that the index most in need of improvement was plumbing construction, followed by Stone construction and pavement construction. design concept was evaluated as appropriate in entire categories. Finally it is suggested that it can be improved in both process of design to enhance the technology and process of construction to enhance the quality management. The constructability of ecological stream needs adaptive management and it must be discussed with its designing which is at the stage before construction. Also it needs discussion with its designer constantly and feed-back process.

한(韓).중(中).일(日)의 식생활문화(食生活文化) 비교연구(比較硏究) (II) - $14{\sim}19$세기, 일상식품(日常食品)을 중심(中心)으로- (A Study on the Comparison Among Korea, China and Japan Food Cultures (II) - From 14C to 19C, on the Daily foods -)

  • 안명수
    • 한국식생활문화학회지
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    • 제12권3호
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    • pp.353-364
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    • 1997
  • A study was carried out to compare the daily foods which were eaten during $14{\sim}19$ century among Korea (Chosun dynasty), China (Ming, thing dynasty), and Japan (Muromachi, Edo era). Specially, in Ming, Ching dynasty, Noodles and dumpling were cooked very often and in Muromachi, Edo era, many kinds of beans were used so much, and there were many kinds of steamed rice to compare with Korea and China. Also, in Japan at these era Woodong, Morisoba, and Somyen were used as favorite foods harbitually. 1. The crops were used as staple foods in three countries such as steamed rice, gruel, noodle, dumpling, rice cake etc. commonly. 2. In Chosun, a roe deer, deer, antelope, and wild boar were more favoite dishes than cow, chicken, and dog, generally people enjoyed to eat pork and chicken. In Ming Ching, pork, chicken, goose, dove, lamb, ass, and duck were used as food materials, also wild animals such as deer, rabbit, and monkey etc. were used. In Muromach era, wild animal as racoon dog, otter, deer, antelope, bear, were used as food materials, in early Edo era (Yayoi and Momoyama), beef and pork were used as daily foods but they were eaten decreasingly in Edo era. So in Japan at those era, the dishes prepared of fishes were more than those of meats. For example, Sushi was made from that time, people all over the world are enjoying to have Sushi at present time. 3. Also in these era, many kinds of vegetables and fruits were used in three countries, and new kinds of vegetables and fruits were introduced from foreign countries, for example, red pepper, pumpkin, sweet potato, potato in Korea, corn, sweet potato, red pepper in China, and water melon, pumpkin, corn, red pepper, marmellow, sweet potato, sugar beet in Japan.

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동해구중형트롤어업의 어구어법 및 제도 개선에 관한 연구 (Fishing gear and method and improvement of regulation of the middle sized trawl fishery in the East Sea of Korea)

  • 장충식;송원상;강명희;조윤형;김보연;안영수
    • 수산해양기술연구
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    • 제52권2호
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    • pp.162-168
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    • 2016
  • This study attempted to help determine Korean fishery policies by proposing improvement plans after examining the current regulations, fishing vessels, fishing gear and fishing methods of the middle sized trawl fishery in the East Sea for targeting only squid. In general, the size, engine horse power, and net length of the middle sized trawlers are between 50 and 60 GT, 1,200 and 1,600 PS, and approximately 165 m with four seamed trawl nets, respectively. While a jigging vessel attracted squids using lights, the trawler approached a jigging vessel. The trawler let the jigging vessel know its decision for fishing, and then jigging vessel rolled up jigs. The net of the trawler was casted at 45 degrees between the bow and the stern of the jigging vessel. Once the trawler towed close to the stern of the jigging vessel upon its passing of the jigging vessel, the bow of the trawler turned 45 degrees left again. Then, squid aggregations were entered into the net. When the cod end was passed a light vessel, the trawler hoisted the net up to the otter board. Then the trawler turned 180 degrees. It repeated three to five times of fishing operations as the previous method. We recommend that the regulations allow nineteen side trawlers to catch like stern trawler, as well as the cooperative trawler and jigging vessel operations.

일점오양분선택모형을 이용한 청주·청원 지역의 수달 서식지 보호의 비시장적 가치추정 (Using One and One-Half Bounded Dichotomous Choice Contingent Valuation Methods to Estimate Non-market Value of Otters in Cheongju·Cheongwon Area)

  • 유진채;김정은
    • 자원ㆍ환경경제연구
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    • 제17권2호
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    • pp.349-379
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    • 2008
  • 수달은 준멸종위기 야생동물이자, 생태적으로 건강한 하천의 지표종이다. 본 연구의 목적은 청주시와 청원군의 수달 서식지 보호의 비시장적 가치를 측정하는 것이다. 응답자의 지불의사를 추정하기 위하여 일점오양분선택형 조건부가치측정법을 적용하였다. 청주 청원 지역 거주민 311명의 표본을 대상으로 수달 서식지 보호를 위한 지불의사를 물었다. 청주 청원 지역 거주민들이 부여한 수달 서식지 보호치 지불의사는 일점오양분선택형 선형로짓모형의 중앙값을 대표값으로 선정하면, 가구당 매월 5,904원으로 산출되었다. 2005년 현재 청주 청원 지역내의 총 가구수가 255,750가구임을 감안하면 총 가치는 매월 12억~17억 원으로 추정된다. 본 연구의 결과는 공익적 편익을 제공하는 수달 서식지 보호정책의 필요성을 시사한다.

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고리 주변 해역 새우류의 종조성과 계절 변동 (Species Composition and Seasonal Variation of Shrimp Assemblage in the Coastal Waters of Kori, Korea)

  • 허성회;안용락
    • 한국수산과학회지
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    • 제32권6호
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    • pp.784-790
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    • 1999
  • 고리 주변 해역에 서식하는 새우류의 종조성과 계절 변동을 알아보기 위해 1996년 1월부터 12월까지 소형 otter trawl을 이용하여 새우류를 매월 소조기에 채집하였다. 조사기간 동안 채집된 새우는 6과 11종이 었으며, 자주새우 (Crangon affinis)가 매우 높은 점유율로 연중 우점하였다. 출현량의 계절 변동을 살펴보면, 6$\~$7월과 11월에 높은 값을 보였으며 겨울과 초가을에 낮은 간을 보였다. 출현종수는 다른 계절에 비해 겨울과 봄에 많았다. 종다양도지수는 1월$\~$3월에 높은 값을 보였고, 7$\~$8월과 11월에 낮은 값을 보였는데, 이 시기의 낮은 값은 자주새우의 극우점에 의해 초래되었다. 본 연구 해역에서 채집된 새우류는 출현 양상에 따라 주거종과 계절종으로 나눌 수 있었다.

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어류가 대량으로 입강했을 때의 선미 trawl의 warp 장력 (THE INFLUENCE OF CATCH VOLUME ON TRAWLER WARP TENSION)

  • 김차돌
    • 한국수산과학회지
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    • 제2권2호
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    • pp.173-178
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    • 1969
  • (1) 1968년 6월 18일부터 7월 16일 사이에 일본수산청 어업조사선 Kaiyo-Maru에 승선 New Zealand 근해에서 trawl 실험을 행하였다. (2) 대형선미 trawl에 있어 예강초와 양강직전의 warp 장력간의 차는 입강어의 다과와는 상관이 없는 것 같다.

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어구에서 발생되는 소음 -트로올 어구- (UNDERWATER NOISE GENERATED BY FISHING GEAR -Stern trawl net-)

  • 윤갑동
    • 한국수산과학회지
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    • 제12권4호
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    • pp.217-224
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    • 1979
  • 조업중의 어선이나 어구로부터 발생되는 수중소음의 음향특성을 구하기 위하여 특별히 고안된 수중녹음장치를 이용하여 트로올어구의 수중소음을 녹음분석한 결과는 다음과 같다. 1. 조업중인 트로올어구에서 측정수 소음에는 어선이 발하는 소음의 영향을 극히 적다. 2. 소음의 주파수분포는 $DC\~6,300\;Hz$이고 그 중 우세한 주파수대는 $100Hz\~6,300Hz$이며 최대음압은 $137db(re\;1:{\mu}Pa$이었다. 3. 뜸줄부보다 발줄부에서 음압준위가 높고 자루부분에서의 음압준위가 가장 낮았다. 4. 예망중일 때보다 양망중일 때가 음압준위가 높고 투망중의 음압준위가 가장 낮았다. 5. 예망중의 트롤어구에서 발생되는 수중소음의 주된 음원은 어구의 ground rope와 해저의 마찰음 및 otter board와 해저와의 마찰음이라고 추정할 수 있다.

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