• Title/Summary/Keyword: By-catch

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MODEL EXPERIMENT OF STOW NET (안강망어구의 모형실험)

  • KO Kwan Soh;KIM Yong Hae
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.12 no.4
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    • pp.201-207
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    • 1979
  • The stow net now used in the Yellow Sea, are traditional bag net with the opening held by a lighter upper and a weighted lower beams standing against the current. Such bag net anchored at the bottom are known in many countries, particularly in the estuaries of large rivers, but more rarely in sea fisheries, because they are too much affected by the weather, moreover a permanent strong current is necessary. Some scientists intended to improve this fishing gear, using the shearing devices instead of a lighter upper and a weighted lower beams in order to widen mouth of the stow net however they are unsuccessful. One-fortieth scale model net of the stow net was tested in a circular water tank with an effective volume of $5.67m\times1.76m\times1.00m$ of observing the configuration and tension of the net. Experiments were carried out under the various combination including water velocity, spherical floats and elevating floats with the shearing hoods instead of the upper beam. We found those devices offered a very low resistance per net area to current compared with the spherical floats or upper beam, and had a fairly good shearing power at any velocity and direction of the current. The total resistance (R) of the model net to which shearing hoods and floats are attached can be induced by the following formula under the condition of 0.25m/sec to 0.5m/sec, $$R(kg)=3.11V^{1.54}$$ The height (h) of the improved model net (m-B) is higher than traditional model net(m-A) with upper and lower beams, m-A: h(cm)=89.22-2.42(V-15). $V\geqq15,\;cm/sec$ m-B: h(cm)=89.20-0.78V (V:cm/sec) The catch efficiency of improved model net is 1.5 times traditional model net.

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Seasonal variation in species composition of catch by a coastal beam trawl in Jinhae Bay and Jinju Bay, Korea (진해만과 진주만에서 새우조망으로 어획된 수산자원의 계절변동)

  • Song, Mi-Young;Kim, Joo Il;Kim, Sung Tae;Lee, Jong Hee;Lee, Jae Bong
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.48 no.4
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    • pp.428-444
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    • 2012
  • The species composition and seasonal variation of fisheries resources in Jinhae bay and Jinju bay, were studied using shrimp beam trawl through a year of 2010. During the study period, a total of 117 species were collected in Jinhae bay. Species included were 63 species in Pisces and 24 in Crustacea. And a total of 106 species were collected in Jinju bay. Species included were 57 species in Pisces and 31 in Crustacea. The dominant species were Zoarces gilli, Crangon hakodatei and Oratosquilla oratoria in Jinhae bay, and Crangon hakodatei, Leiognathus nuchalis and Charybdis bimaculata in Jinju bay. The samples were mainly grouped according to the location and season on the SOM. Group 1 with sample sites in Jinju bay, was characterized by high values of Parapenaeopsis tenella, Leiognathus nuchalis and Hexagrammos otakii. Group 2 with sample sites in April, were dominant Crangon hakodatei and Luidia quinaria. The samples in Group 3 were high values of Charybdis bimaculata and Pleuronichthys cornutus. Group 4 with sample sites in Jinhae bay, was characterized by high densities of Zoarces gilli and Pholis fangi. The dominant species, Crangon hakodatei, were catched egg-bearing females until June. Zoarces gilli and Leiognathus nuchalis were presented small size individuals during study period. It represented that study area is an important role in spawning and nursery ground for fisheries resources.

Fluctuation of Bag-net Catches off Wando, Korea and the Effect of Sea Water Temperature (한국 완도해역 낭장망 어업의 어획량 변동과 수온의 영향)

  • Kim Jin Koo;Choi Ok In;Chang Dae Soo;Kim Joo Il
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.35 no.5
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    • pp.497-503
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    • 2002
  • Fluctuation of the yield of anchovy, Engraulis japonicus and species composition of by-catch were examined to clarify the effect of sea water temperature using samples by bag net off Wando, west southern of Korea from 1999 to 2001. In 1999 and 2001, sea water temperature were higher than 20$^{\circ}C$ from July to October, However that of 2000 was higher than 20$^{\circ}C$ from August to September owing to the strong tidal front formed in south western area of Korea from late spring to summer. Fish captured by bag net off Wando was composed of approximately 73 species which belonging to the juveniles and young stages. Among them, Gymnapogon urospilotus, Lagocephalus sp., Omobranchus elegans, Platycephalus indicus and Konosirus punctatus did not appeared in 2000 when tidal front were developed stronger than in 1999 and 2001. Yield of anchovy landed at fishery of Wando were 1,000 M/T in 1999, 620 M/T in 2000, 1,056 M/T in 2001 respectively and have a tendency to increase from July to August and reach to maximum from August to October.

A Model for Evaluating Eco-friendly Demolition Works for Remodeling in the Pre-construction Stage (친환경 리모델링 철거공사 수행을 위한 사전검토 모델 개발)

  • Chae, Seong-Hyun;Kim, Kyung-Rai;Shin, Dong-Woo;Cha, Hee-Sung
    • Korean Journal of Construction Engineering and Management
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    • v.13 no.1
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    • pp.14-23
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    • 2012
  • Due to the increase of aged housing demolition in preparation for the rapid growth of the market, Eco-friendly remodeling demolition work which can minimize environmental destruction have been studied. However, the owner or contractor to apply for eco-friendly remodeling demolition work does not reflect the characteristics of the site can not have a potential for many variables. In addition, There is no standard which can find effective part and catch a problem by performing eco-friendly remodeling demolition. Therefore, the project owner and construction company executives in the Pre-construction stage to the implementation of eco-friendly remodeling demolition construction by providing a model for the pre-evaluating the project. In this paper, the performance of eco-friendly remodeling of demolitions is proposed for the pre-evaluating model. After the eight items were drawn affecting the performances which are influence to accomplishment of the eco-friendly remodeling demolition, evaluation criteria was suggested for each item. Also By classifying and assessing the evaluation items, It will be able to identify the problems and supplements for eco-friendly remodeling demolition. Through the final evaluation sheet, The works of the appropriacy and supplement will be checked for the eco-friendly remodeling demolition. Finally The preinvestigation model is helpful for making the plan of systematic demolition, futhermore It is contribute to the expansion of the eco-friendly remodeling demolition.

The Exploitation of World Fishery Resources for 10 Years under the New Regime in the Sea (신해양질서 10년후 세계어업자원 이용동향)

  • 이장욱;허영희
    • The Journal of Fisheries Business Administration
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    • v.23 no.1
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    • pp.43-87
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    • 1992
  • In this paper, state of exploitation of world fishery resources after 10 years under the new regime in the sea, called the era of exclusive economic zone (EEZ) expending up to a 200 nautical miles from coastal line, was reviewed to determine effect from establishing EEZ in the world fishery production and its export/import volume based on the fishery statistics annually published by the Food and Agriculture Organization (FAO) of United Nation. The world total production from marine living resources had a trend showing a waned increase during 1970's when most of coastal states were translated into the reality of EEZ. From mid-1980's onwards, it increased rapidly, reaching about 85 million tons . Such increase in production was basically from the Pacific Ocean, accounting for more than 60% of the world total production. Fishing areas where showed increase in the production after the new regime in the sea were the southwestern Atlantic (FAO area 41) , the eastern Indian (FAO area 57) and the whole fishing areas in the Pacific except the eastern central Pacific (FAO area 77). Increase in the production from distant-water fishing countries came from the regions of the southwest Atlantic (FAO area 41) and the southwest Pacific (FAO area 81) . The production from coastal states was up from the regions of the eastern Indian (FAO area 57) , the northwest and northeast Pacific (FAO areas 61 and 67) and the southeast Pacific (FAO area 87) . It was likely that the exploitation of the fishable stocks was well monitored in the areas of the northwest Atlantic (FAO area 21) , the eastern central Atlantic (FAO area 34) and the northeast Pacific (FAO area 67) through appropriate management measures such as annual harvest level, establishment of total allowable catch etc. The marine fisheries resources that have made contribution to the world production, despite expansion of 200 EEZ by coastal states, were sardinellas, Atlantic cod, blue whiting and squids in the Atlantic Ocean : tunas which mainly include skipjack, yellowfin and bigeye tuna, croakers and pony fishes in the Indian Ocean : and sardine, Chilean pilchard, Alaska pollock, tunas (skipjack and yellowfin tuna) , blue grenadier and blue whiting including anchoveta in the Pacific Ocean. It was identified that both fishery production and its export since introduction of the new regime in the sea were dominated by such coastal states as USA, Canada, Indonesia, Thailand, Mexico, South Africa and Newzealand. But difficulties have been experienced in the European countries including Norway, Spain, Japan and Rep. of Korea. Therefore, majority of coastal states are unlikely to have yet undertaken proper utilization as well as rational management of marine living resources in their jurisdiction during the last two decades. The main target species groups which led the world fishery production to go up were Alaska pollock, cods, tunas, sardinellas, chub and jack mackerel and anchoveta. These stocks are largely expected to continue to contribute to the production. The fisheries resources which are unexploited, underexploited and/or lightly exploited at present and which will be contributed to the world production in future are identified with cephalopods, Pacific jack mackerel and Atlantic mackerel, silver hake including anchovies. These resources mainly distribute in the Pacific regions, especially FAO statistical fishing areas 67, 77 and 87. It was likely to premature to conclude that the new regime in the sea was only in favour of coastal states in fishey production.

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A Political-Economic Study on Cooperative Squid Fishing East to the $E128^{\circ}$ (동경 128도 이동 오징어 공조조업에 관한 정치경제학적 연구)

  • Park Seong-Kwae
    • The Journal of Fisheries Business Administration
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    • v.35 no.2
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    • pp.91-115
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    • 2004
  • The main purpose of this study is to analyze the cooperative squid fisheries problems surrounding the $E128^{\circ}$, established by the 1965 Korea - Japan Fisheries Agreement which banned Korean large trawlers' fishing east to the $E128^{\circ}$ In fact, the moratorium was put on by Japans request. However, such issue did not occur until the filefish stock in the southern Korean sea, which was a major target fish species of the large trawl fisheries, The filefish stock collapsed completely around 1991 and at the same time most of bottom fish stocks in the East China Sea began to show a symptom of over - exploitation. Thus, the off - shore large trawlers learned to have a little opportunity of finding out alternative fish stocks as well as fishing grounds. Fortunately, at that time squid resource stock and consumption were on the increasing trend. The large trawl fisheries were able to economically exploit squid stock east to the $E128^{\circ}$ through cooperative fishing with squid angling light boats in the East and East - South Sea, even though such cooperative fishing activities violate the existing fishery laws apparently. Some important reasons that the large trawlers have continued the cooperative fishing seem to be because (ⅰ) squid resource stock has been on the increasing state over time, (ⅱ) the trawl fisheries have made a significant contribution to meeting domestic and export demands and stabilizing squid prices, and (ⅲ) they have kept domestic squid market from foreign competition. However, the new Korea - Japan fisheries agreement in 1998 provided a momentum of questioning the effectiveness of the $E128^{\circ}$ by the squid - related fisheries other than the squid angling. Serious conflicts between squid - related fisheries began to emerge and to be much intensified. Squid angling industries in the East opposed to large trawlers's efforts to formalize such illegal cooperative squid fishing activities. Their main argument was that such formalizing would definitely make the East coast squid prices lower and in turn their business performance would be worse off. The results of quantitative analysis suggest that the trawlers' massive landing may have a significant influence on lowering the east coast squid prices. Now, an important issue that the squid - related fisheries and the government are facing is to solve such complex squid fishing problems through a multi - participatory negotiation process, including price stabilization, total allowable catch level and its operation schemes, $E128^{\circ}$ rearrangement, and so on.

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Research on the measles experience of A primary school children in the Epidemic area (홍역이환지역 일 초등학교 학생의 홍역경험 조사연구)

  • 김이순;정은순;송미경
    • Korean Journal of Health Education and Promotion
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    • v.19 no.2
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    • pp.115-125
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    • 2002
  • This study is a investigation research to examine total 123 children's thought, perception and coping method about measles, with 62 children who had experienced the measles and 61 good health children in the school, which had spread to a primary school in kyoungsang-bukdo province. The data collection was done from December 6 to December 8. The analysis of data was SPSS(10.0) for descriptive statistics. The data were collected from total 123 children, 62 of them who had diagnosed measles on October, 2000, when the measles had ended, were used a purposive sampling, the others who had a good health were used a convenience sampling. From three to six grade students made out directly the questionaire in the way of self-questionaire, and from one to two grade students, made out answering the question which the researcher had read the items. The researchers call back the students to complement the contents about the items inadequate answers, so they raised the reliability. The results were as follows. 1. The results of observe carefully the measles infection degree by a sex, the boys(27.4%) were sick severely compared with girls(9.7%)were sick weakly compared with the boys(27.4%)(p〈0.01). 2. The 62.9 percents of infected children by measles thought that they were infected at school, regarded the doctors as a first judge, and had caught the measles because of their fault. The results of observe carefully, 33.8 percents children of infected by measles had have a secondary vaccination. To the question whether they go to institute or not while suffering from the measles, 35.5% children didn't go there since they had heard the fact they infected the measles. 3. To a question of asking if close mend caught the measles, what will they do, 65.1% children of caught the measles answer ‘I can't meet my friend'(p〈0.001). It was significant that infected children have more interests than didn't infected children. The 22% children of didn't catch the measles take great interested in health compare with the 12.2% children of infected the measles(p〈0.05). To the question if they listen the preservation of health broadcasting, 63.4% children answer ‘I listen well’. It was significant between the infected group and didn't infect group(p〈0.05). To the question if they delivery to the written information at home, it was significant between the infected group and didn't infect group(p〈0.05). 4. The infected group of 69.1% children think the health is most important in their life school than any other they like study.

3D Medical Image Segmentation Using Region-Growing Based Tracking (영역 확장 기반 추적을 이용한 3차원 의료 영상 분할 기법)

  • Ko S.;Yi J.;Lim J.;Ra J. B.
    • Journal of Biomedical Engineering Research
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    • v.21 no.3 s.61
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    • pp.239-246
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    • 2000
  • In this paper. we propose a semi-automatic segmentation algorithm to extract organ in 3D medical data by using a manually segmentation result in a sing1e slice. Generally region glowing based tracking method consists of 3 steps object projection. seed extraction and boundary decision by region growing. But because the boundary between organs in medical data is vague, improper seeds make the boundary dig into the organ or extend to the false region. In the proposed algorithm seeds are carefully extracted to find suitable boundaries between organs after region growing. And the jagged boundary at low gradient region after region growing is corrected by post-processing using Fourier descriptor. Also two-path tracking make it possible to catch up newly appeared areas. The proposed algorithm provides satisfactory results in segmenting 1 mm distance kidneys from X-rav CT body image set of 82 slices.

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A Study on the effect of Spectrum difference between Cellular and PCS from Mobile Telecommunication Customer's perspective

  • Youn, Young-Seog;Cho, Byung-Sun;Ha, Young-Wook
    • Journal of Korea Technology Innovation Society
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    • v.9 no.4
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    • pp.627-653
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    • 2006
  • The purpose of this study lies in understanding how the spectrum assigned for each mobile operator affects the consumers of mobile service. For this purpose, we have observed the change of path coefficient in the structural equation, using control variables. However, the structure of the mobile service market in Korea has become fixed. Considering this tendency and the conclusion of this study, the 'lock-in effect' occurs seriously in the mobile service market in Korea. It can be explained by the fact that CS(Customer Satisfaction) of the cellular subscribers little affects customer loyalty but the market dominance of the cellular service in the actual market has continued for a long time. In this study, we figured out a strong prejudice about call quality, which is caused by spectrum difference among competitors. Cellular subscribers tends to believe that call quality of their cellular service is better than that of PCS. In addition, we found that PCS operators can catch customer's retention by investment into network in order to increase call quality.

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Long-term variation of zooplankton around Dokdo in the East Sea (독도 인근해역 동물플랑크톤 장기간 특성)

  • Kang, Jung-Hoon;Kim, Woong-Seo;Kwon, Oh Youn;Cho, Kyuhee
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.9
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    • pp.422-430
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    • 2016
  • We investigated the abundance and composition of the zooplankton community around Dokdo in the East Sea from 2006 to 2015. Zooplankton samples were collected in the surface mixed layer by vertical hauls using a standard type net at the monitoring stations. There were no clear long-term trends in the average temperature and salinity, but relatively low salinity was recorded in the summer of 2013 and 2015. The average abundances of zooplankton in the summer increased by two orders of magnitude from $317inds./m^3$ in 2008 to $10,242inds./m^3$ in 2015. This long-term increase was accompanied by a slight increase in the chlorophyll-a concentration and a decrease in the catch of potential crucial predators (anchovy, mackerel pike, squid, herring and horse mackerel) in the study area. The dominant zooplankton, accounting for most of the long-term increase, consisted of appendicularian (Oikopleura spp.), which showed a steady increase since 2012, summer species such as Noctiluca scintillans and the cladoceran Penilia avirostris, which showed an abrupt increase, and the copepod Paracalanus parvus s.l., which showed a rapid increase after its first occurrence in summer 2010. These results suggest that the long-term increase of zooplankton could be related to the increase in the concentration of prey and the decrease in the predation pressure of potential predators around Dokdo in the study area.