• Korean Journal of Ichthyology
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• v.20 no.4
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• pp.303-312
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• 2008

Seasonal variation in species composition and abundance of fishes was determined using monthly samples collected by a fyke net in coastal waters off Namhae Island in 2006. The sampling gear, both-side fyke net, is a widely used commercial fishing gear in shallow waters of the region. A total of 89 fish species was collected, the dominant species were Konosirus punctatus, Mugil cephalus, Lateolabrax japonicus, Acanthopagrus schlegeli, Sebastes inermis, Nibea mitsukurii, Clupeapallasii, Pampus echinogaster, Sebastes schlegeli and Limanda yokohamae. They accounted for 61.1% of the total number of individuals and 80.3% of the biomass. The dominant species were primarily composed of small individuals or juveniles of large-sized fishes. Abundance in the number of individuals and biomass showed peaks in April, May and September, and was lowest in January. Temporal change in fish abundance was related to the temperature and related factors.

• Korean Journal of Ichthyology
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• v.20 no.4
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• pp.291-302
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• 2008

Seasonal variation of species composition in the coastal waters off Wangdol-cho were investigated using the catches by gill net and trammel net from 2002 to 2004. A total of 58 species was collected and classified into 15 orders and 34 families. Of the 58 species identified, Scorpaeniformes and Perciformes accounted for 62.1% of the species. 35 species in 11 orders and 22 families were collected by gill net and 51 species in 15 orders and 30 families were collected by trammel net. The number of species was high in summer and autumn and lowest in winter. Catches were correlated with sea water temperature. The numbers of individuals and their biomass were 5,295 inds. and 1,890 kg, with the highest values achieved in summer and the lowest in spring. The most dominant species were Pleurogrammus azonus and Gadus macrocephalus. The seasonal species community showed a high similarity between summer and autumn.

• Journal of Fisheries and Marine Sciences Education
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• v.12 no.1
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• pp.11-21
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• 2000

Most of artificial reefs in the examined areas were normally established except for some lower parts demersed slightly, and some to function. 1) Twenty species of fish were captured by fishing gear, and 10 species were observed by scuba in the examined areas. 2) Five algal and five fisheries animal species were observed as fouling organism. 3) C.P.U.E of trap, long liner and gill netter in the examined areas was respectively 2.12, 10.23, and 4.93, where as that in contral was established as 1.41, 4.43 and 2.86. 4) Species composition by the fishing gear the trap, long liner and gill netter in the examind areas was respectively 94, 85 and 118, where as that in control was established as 58, 37 and 62. Accordingly, The fishing effects in the artificial reefs installation sector was two times higher than comparative sector.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.39 no.2
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• pp.87-91
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• 2003

Experimental fishing was carried out to investigate the survival rate of fishes discarded after hauling from the trawl and to develop the fishing gear and method for fisheries management which can improve the survival rate of young fishes escaped from the trawl codend in offshore korean southern sea and off Cheju Island of Korea. The young fishes were bred in fish cage on the board to measure the sustainable survival time for fishes escaped from grid panel and codend. The obtained results are summarized as follows' 1. Japanese flying squid(Todarodes pacjficus), mitra squid(Loligo chinesis), hair-tail( Trichiurus lepturus), john dory(Zeus japonicus), spanish mackerel(Scomberomorus niphonius), redlip croaker (Pseudosciaena polyactis) and blackthroat seaperch(Doederliinia berycoides) were dead instantly after hauling. 2. Survival rate of tiger shark(Galeocerdo cuvier), conger eel (Conger myriaster), red skate (Dasyatis akajei), black scraper(Navodon modestus) and japanese fan lobster(Ibacus ciliatus) might be high after discarding because they survived for long hours in fish cage. 3. Blotched eelpout(Zoarces gili) escaped from the escapement device(grid) was dead within 6 hours in the water tank installed on the board but 97% of tiger shark and 72% of conger eel survived over 72 hours. 4. Red skate escaped from trawl codend was dead within 60 hours in the water tank installed on the board but sustainable survival time of 25% of octopus(Paroctopus dofleini) and 100% of black scraper was over 72 hours. 5. Compared with the survival rate of rosefish(Helicolenus higendorfi) escaped from the escapement device(grid) and trawl codend, all of the rosefish escaped from the grid was dead within 7.2 hours but 8.3% of the rosefish escaped from the codend survived over 72 hours. 6. In comparison with the survival rate of japanese fan lobster survived over 72 hours, survival rate of japanese fan lobster escaped the codend was much higher as 75% than 33% of japanese fan lobster escaped from the grid.

• Korean Journal of Ichthyology
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• v.24 no.2
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• pp.84-93
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• 2012

Fish species composition and abundance in the waters of nearby Nakdong River estuary were investigated non-continuously and seasonally by shrimp beam trawl in summer 2007, winter 2009, and from spring 2010 to autumn 2010. During the study period, total fish species were collected 92 species, 36 families in study area. Shannon index was 1.893~2.962, and evenness was 0.050~0.231. Fish species composition was shown interannually and seasonally variations in the waters of nearby Nakdong River estuary. We carryed out cluster analysis to contain the data in previous and current study. Fish species composition was divided 3 groups which were 1987~1988 and 1998, 2001~2002, and 2007~2008 and 2009~2010. Average and minimum length in this study was longer than its in previous studies, and length range in this study was wider than its in previous studies, too. Dominant fish increased individuals and weight per unit area in this study. Especially Lophius litulon, Raja kenojei, Eopsetta grigorjewi, and Zeus faber were much better than past 2002. Liparis tanakai, Repomucenus valenciennei and Leiognathus nuchalis were dominant fish in previous study, but those decreased individuals and weight per unit area in this study.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.24 no.1
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• pp.18-29
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• 2019

ROV surveys were conducted using 500 meter mini class ROV with HD video camera, 2 LED lights, a simple manipulator and 8 thrusters near the Dokdo and Simheungtaek seamount. Total six dives have been conducted using the ROV "V8 SII" from Sweden and ROV's support ship, "KOSAL V" at 4 stations between 45 and 370 meters with diving time ranged from 30 to 120 minutes. Dense communities of sea anemone (Actinostolidae sp.) and ophiuroids (Ophiuridae sp.) on the surface of rocky bottom and snow crab on the soft bottom with muddy-sand were observed at northwestern part of Simheungtaek seamount. We obtained the following results 1) habitats information for snow crab, one of the major fisheries resources, and deep-sea fauna, 2) observation on the specific topography and sediment conditions, 3) observation of the seabed surface covered with the discarded fishing gears. This study represents the first report of in situ visual observation of deep-sea organisms and their habitats near the Dokdo slopes and flat top of the Simheungtaek seamount in the East Sea. These results indicated that immediate oceanographic survey using the mini class ROV is available in the East Sea.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.33 no.4
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• pp.298-310
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• 1997

The aim of this research was to evaluate the biotic environments based upon the community pattern of demersal fishes in the Masan bay which is heavily polluted area in the southern part of Korea. The baited traps or bottom gillnet sampled bottom fishes at four sites totally 14 tunes from March 1994 to December 1996 with 2~3 months interval. The baited trap caught 0~ 10 species which were mainly starfish, crabs, conger eel, rockfish, or blenny with 0~50 individuals per a trap. Small crab(Atergatis sp.) was significantly dominant in the S1 site, most heavily polluted area, and starfish(Asterias sp. and/or Asterina sp.) in the other three sites. There was no animals at the S1 site in the March and July in 1994 and August in 1996. The gillnets caught 0~7 species which were mainly mantis shrimp, jellyfish, flounder, starfish, crabs, or sea weeds with 0~30 individuals per a pannel of bottom gillnet. Jellyfish was significantly dominant in the S1 site and mantis shrimp in the all four sites. There was no animals in the July 1994 at S1 site and in the August and December 1996 at S4 site. But at the August in 1995 or 1996 in the S1 site, the bottom gillnets caught mackerel, anchovy, gizzard-shad or mullet which was dead all. The species diversity index of samlings by trap or gillnet showed less than 1.0 in the 80% of the totally 56 samplings. This means that the stability of demersal fishes' community is very low owing to the poor biotic environments. But most of fishes living at Masan bay appeared well fitting with the heavily polluted environments. And some fishes, like mackerel, anchovy, gizzard-shad or mullet migrated into polluted Masan bay with the seasonal or annual fluctuation.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.31 no.1
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• pp.1-7
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• 1995

The fish behavior survey in the main-net of a large scale-net was carried out in relation to the catching function of the set-net. at Kishihata set-net in Japan during the period from January 29th to February 22th 1992. The results obtained are summarized as follows; 1. The greatest number of schools observation in the main-net occurred between 17 : 00hrs and 18 : 00hrs. after which the schools suddenly disappeared. This result show that the schools did not stay in the main-net. but immediately moved through into the bag-net or left the main-net. 2. The course of movement of the small schools of sardine in the main-net was in a straight line to the slope-net. However. upon arrived at the slope-net the school turned around. away from the slope-net and went directly towards the playground. 3. The majority of small schools of sardine in the main-net were estimated to move with the mode velocity 25cm/sec. however the maximum velocity were recorded 80cm/sec.

• Journal of the Korean Society for information Management
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• v.30 no.3
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• pp.23-48
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• 2013

This study compared and analyzed 15 CBMR (Content-based Music Retrieval) systems accessible on the web in terms of DB size and type, query type, access point, input and output type, and search functions, with reviewing features of music information and techniques used for transforming or transcribing of music sources, extracting and segmenting melodies, extracting and indexing features of music, and matching algorithms for CBMR systems. Application of text information retrieval techniques such as inverted indexing, N-gram indexing, Boolean search, truncation, keyword and phrase search, normalization, filtering, browsing, exact matching, similarity measure using edit distance, sorting, etc. to enhancing the CBMR; effort for increasing DB size and usability; and problems in extracting melodies, deleting stop notes in queries, and using solfege as pitch information were found as the results of analysis.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.47 no.1
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• pp.1-9
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• 2011

In order to investigate the cause and magnitude of scale effect occurring in the model experiments of fishing nets, five pairs of Nylon pyramid nets and one pair of PE ones in which all the two nets paired were equal each other in the factors determining their flow resistance, i. e., the ratio d/l of diameter d to length l of bars, the angle f between two adjacent bars, the attack angle q of nettings to the water flow, and the wall area S of nets, and different in the values of d and l were prepared. Then, the nets were attached to the circular steel frame alternately and their flow resistances with shapes in water were measured on the sea ascribing no turbulent flows by using the tension meter made of a block bearing for the experiment. All the Nylon nets were spreads out easily in water to form a circular cone at relatively low velocity of water and showed the resistance smaller a little in the nets with larger d and l than them with smaller d and l, because the filtration of water through meshes become easier in nets especially with larger l. But PE nettings were not spread out sufficiently on account of their small flexibility and showed higher resistance especially in them with thicker twines. Therefore, the difference in bar length or mesh size and flexibility of nettings between prototype and model nets are regarded to become factors ascribing scale effect. Especially the influence of the difference in mesh size may become large significantly in actual model experiments because the mesh size of model nets is decided at much larger value than that given by scale ratio and so the difference of mesh size between the two nets become much larger than that between nets used in this experiment.