• 한국수산과학회지
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• 제48권6호
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• pp.960-968
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• 2015

This study examined the spatiotemporal distribution of demersal fish aggregations in the Northern East China Sea by conducting a trawl survey with hydroacoustic devices. A bottom trawl was used for this survey and fish density was determined from the catch data. Acoustic data were collected at frequencies of 38 and 200 kHz from November to December 2014 and converted into the nautical area scattering coefficient (NASC, $m^2/n{\cdot}mile^2$). In the catch data analysis, the range of catch per unit area by station was $26-8,055kg/km^2$ and for the acoustic data, that of the NASC was $0.45-34.80m^2/n{\cdot}mile^2$. The values were significantly correlated. The combined results of both surveys found that the density was highest at St. 5 ($33^{\circ}$ 10.3', $126^{\circ}$ 23.3') and lowest at St. 8 ($33^{\circ}$ 20.7', $127^{\circ}$ 36.3'). The application of hydroacoustic methods offers a new approach for estimating the biomass of demersal fish aggregations.

• 한국수산과학회지
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• 제44권5호
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• pp.499-505
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• 2011

The fishing grounds of Korean large-pair trawlers have shifted since exclusive economic zones (EEZs) were established in a fisheries agreement involving countries neighboring Korean waters. The distributions of marine ecosystems and fisheries resources have been changing with environmental changes such as global warming and with the shift in species targeted as a result of changes in fishing technology and fishing gear. This study analyzed variation in the species assemblages caught in Korean waters by large-pair trawlers as a result of these geopolitical and environmental changes. The data used in this study were obtained from the Fishery Production Statistics of Korea and the Port Sample Survey of the National Fisheries Research and Development Institute (NFRDI) from 1990 to 2007. Hierarchical clustering analysis (HCA) and correspondence analysis (CA) were used to explore the characteristics of the catch-species composition. The overall variation in the species composition of the catch of Korean large-pair trawlers showed that the proportions of croaker Johnius grypotus, small yellow croaker Larimichthys polyactis, eel Anguilla japonica, and blue crab Portunus trituberculatus decreased, whereas those of hairtail Trichiurus lepturus, Spanish mackerel Scomberomorus niphonius, anchovy Engraulis japonicus, and common squid Todarodes pacificus increased in Korean waters over the 18-year period. The results of the HCA of the annual catch data by species showed four different distributions of fish species according to year. Results of the CA showed that the species assemblages differed between the 1990s and 2000s.

• 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.

• 한국수산과학회지
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• 제43권6호
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• pp.740-746
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• 2010

This study standardized the catch per unit effort (CPUE) of bigeye tuna (Thunnus obesus) caught by the Korean longline fishery in the Pacific Ocean. The study used a general linear model (GLM) to standardize the CPUE using catch and effort data aggregated by year, month, and $5{\times}5$ degrees of latitude and longitude in the tropical Pacific Ocean from 1982 to 2008 (except for 1988 and 1989). Explanatory variables in the GLM analysis included year, month, subtropical area, and number of hooks between floats (HBF). The study area and HBF were subdivided into three subtropical areas and six classes, respectively. During the study period, the standardized CPUE was significantly related to the nominal CPUE. The standardized CPUE declined sharply, as compared to the nominal CPUE, after the mid 1990s. In particular, the decline in the standardized CPUE in all subtropical areas in the 2000s was clearer than that of the nominal CPUE.

• 기술경영경제학회:학술대회논문집
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• 기술경영경제학회 2004년도 제24회 동계학술대회 논문집
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• pp.288-315
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• 2004

This paper has examined the leapfrogging thesis with the case of catch-up in digital TV by the Korean firms. Despite the disadvantages implied by the technological regime of digital TV and the risks facing early entrants in trajectory choice and initial market formation, the Korean firms had achieved a 'path-creating catch-up' in the sense they chose a different path from the Japanese forerunning firms. As they have been closely watching the technological trends and the standard setting process, there was less risk of choosing the right or wrong technological trajectory. Also, despite the lack of sufficient capability and core knowledge base, the Korean firms had some complementary asset, such as the experience of producing analogue TV, and were able to develop the prototype digital TV and the ASIC chips, given the accesses to the foreign knowledge via overseas R&D posts and acquisition of a foreign company. To secure the initial market size, the Korean targeted the US market from the beginning, and their sources for competitive advantages were the speedy setting up the production system for mass production of products at the initial stage. The initial failure of the Japanese firms and the success of the Korean firms do suggest that the period of paradigm shift, like this toward digital technology, can serve as a window of opportunity for late-comers while penalizing the forerunner.

• 수산해양기술연구
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• 제32권3호
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• pp.223-234
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• 1996

Distribution of Anchovy was analyzed from the experimental operations by the small anchovy drag net fishery in the coastal area of Yang yang - gun and Myongju - gun of Kangwon Province from October to December, 1994. Temperature ranged from $11.4^{\circ}C.$to $17.4^{\circ}C.$throughout the experimental period. Fishes caught by experimental operation vessels were composed of anchovy, Clupanodon Punctatus, Pleuronectidae, Tetraodantidae, Acanthopagrus Schlegeli etc., and the anchovy occupied more than 99.6% of the total catch. Anchovy was characterized by the most abundance of the catch for the individual less than 6cm and the gradual increase after October for those larger than 6cm. CPUE(catch per tow) of anchovy was 684kg in October, 784kg in November, 1,590kg in December and mean CPUE of 3 months from October to December was 1,066kg. Fishing grounds of anchovy were formed in coastal area, from $37^{\circ}$45'N to $38^{\circ}$04'N, off Kangwon Province. Distribution density of anchovy in Chumunjin - up, Kyohang - ri Sachon - myon, and Sachonjin - ri coasts was higher than the other areas. Anchovy caught in this surveyed area was recruited from July to September at the length class between 2cm and 3cm, and grew to the sizes between 4cm and Bem in October, between 5cm and tcm in November, between tcm and Bem in December. Recruitment of anchovy increased from July to September and suddenly decreased after September. Individual number of the population was the largest during the period from August to October and gradually decreased after October. Biomass continuously increased after August, and was the largest in December.

• 수산해양교육연구
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• 제28권4호
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• pp.1159-1170
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• 2016

This study examines the distribution and taxonomy of sea horses in South Korea, specifically sea horses that were caught in the Southern Sea, centering on Yeosu, South Korea. Specimen collection methods The samples were collected by set net, skimming nets, dragnets, and landing nets on a boat, as well as scuba diving. A total of 128 sea horses belonging to three species were collected. To investigate the exact distribution pattern, the catch per unit effort and the population density per $1,000m^2$ were calculated for each site in the Southern Sea. The result shows the highest catch by set nets was 29 sea horses a day in Site B at Dolsan-eup, Port Impo, and the highest catch by scuba diving was 8 sea horses a day in Site B at Gijang-gun, Busan. The highest population density was 61.2 sea horses in the coast of Gijang-gun, Busan. Genetic information analysis and morphological analysis were performed for determination of species. As a result, four Hippocampus trimaculatus, (flat-faced sea horses), 45 Hippocampus coronatus (Crowned sea horses), and 79 Hippocampus mohnikei (Japanese sea horses) were distinguished.

• 한국응용곤충학회지
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• 제45권2호
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• pp.161-167
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• 2006

귤굴나방, Phyllocnistis citrella Stainton은 운향과(Rutaceae) 특히 감귤류를 가해하는 해충으로 성페로몬 (Z,Z)-7,11-hexadecadienal (7Z,11Z-16:Al)에 대한 귤굴나방의 반응 특성을 조사하였다. 귤굴나방의 포획효율은 7Z,11Z-16:Al을 미끼로 한 끈끈이날개트랩을 이용했을 때 높았다. 귤굴나방이 유인되는 시간대는 일출과 일몰시간이 관여하고 있으며, 그 시간은 오전 2$\sim$6시로 일일 유인수의 93.1%를 차지하였다. 또한 이 시간대의 평균온도와 풍속, 강우가 귤굴나방 트랩 포획에 미치는 영향을 조사한 결과 풍속의 영향이 가장 높았다. 평균온도 13$^{\circ}C$이하에서는 유인수가 감소하였으나 그 이상의 온도에서는 별다른 영향이 없었다. 풍속은 2.0 m/sec 이상일 때에는 유인수가 급격히 줄어드는 경향이었으며, 강우는 별다른 영향이 없었다.

• 수산해양교육연구
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• 제15권2호
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• pp.166-175
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• 2003

In order to offer fundamental data for the standard of comfilation of the budget on the compensation money for the reduction of fishing baot and index of investigation for computation on the average earnings of reduction of fishing boat, the fluctuation of actual outputs, expenses, earnings and the difference by type of coastal and off-shore fishery was investigated and analyzed. The results are as follows : 1. The average ouput money by large powered purse seine fishery was much with about 3,510 million won, but the average output money by off-shore gill nets fishery was little with about 8.4 million won. 2. The average catch by large powered purse seine fishery was many with about 296,000 M/T, but the average catch by eastern sea danish seine fishery was few with 4,600 M/T. 3. The average expense by large powered purse seine fishery was much with about 3,360 million won, but the average expense by diving fishery was little with 6.3 million won. 4. The average earning by large powered purse seine fishery was much with about 240million won, the average earning by offshore long line fishery was little with 18 million won. 5. The average earning rate by diving fishery was much with 31.62%, but the average earning rate by large powered purse seine fishery was little with 7.30%.

• 수산해양기술연구
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• 제22권4호
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• pp.61-70
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• 1986

In accordance with a rapid growth of demani on aquatic animals, researches of the unused fishery resources On the deep sea b~d in the Korean Waters has been and will be required. The authors carried out a series of fishing experiments to investigate the available resources and to find the effective fishing method on the deep sea bed of the Korean East Sea. In the experiments, 19 kinds of traps which are different from each other in shape, mesh size and entrance diameter were used. The fishing experiments w~r;; carried out in four areas of 20Dm, 600.'11, 800m and 1000.'11 deep respectively, by the Pusan 402 (30:) GT) and the Pusan 403 (279GT), the training ships of National Fisheries University of Pusan, during August, 1986. The catc~ were analyzed with the size, the depth and the construction of traps. The results obtained can be summarized as follows: 1. Main species of the catch w~re pink shrimp, Pandalus bolelis, a kind of welks, Buccimum striatissimum and a kind of larg~ crabs. Chiono8cetes japonicus and the another species were few. 2. The CPUE value (expressed by the number of catch per trap in this paper) of pink shrimp was the highest in the depth of 20J-n around, and the value in the depth of 600.'11 or more decreased gradually with an increase of the depth. But, the value of Buccimum straitissimum was much higher in the depth of 6:J:)!1I or more than that in the depth of 200m around. On the other hand, the value of Chion:Jecetes japonjcus was very low in general. 3. The iniividual body size of the catch differed with the depth. Pink shrimps caught in the depth of 200m around were smaller than those in the depth of 600.'11 or more. In contrast with this, Baccimum striatissim:t.m caught in the depth of 200m around were larger than those in the depth of 600.'11 or more. 4. Depending on the selection curve in Ishida's method for the mesh size of trap webbing, the carapace length of pink shrimp and the shell length of Buccimum striatissimum which are equivalent to 100% relative catching efficiency can be estimated about 3.5cm and 6.5cm or so respectively. 5. The number of catch of pink shrimp and Buccimum striatissimum by the 60.'1'1.'11 entrance diameter of trap were less than that by the 90mm, 120mm and 150mm, even thogh the diffierence am~r, g 9:Jmm, 120.'11.'11 and 150:1'.'11 are not so large.