• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 1998.10b
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• pp.11-25
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• 1998

Many Countries have made efforts to assist ships navigate accurately , safely and expeditiously for the safety control against increasing marine traffic , in their coastal waters. However, they are exposed in spite of these efforts,to risks of casulaties and marine polluation caused by traffic congestion when ships are navigating through waterways approaches to ports or harbors and in narrow fairways. Therefore, efficient control of VTS in Port is necessary nowadays to provide ships with necessary service , which interacts with shipping and organize the flow of traffic so as to maximize the efficiency of the port or harbor while minimizing the risk of accident and environmental pollution. Even though the navigation condition of ships is very inferior compared to other ports in Korea, such as the big difference between the ebb and flood tide, the frequent fog, the narrow fairway , the density of navigation traffic in Inchon Port is high and transportation quantity of dangerous cargoe increases gradually. In cosideration of the characteristics of natural circumstance and traffic circumstance the VTS established newly in Inchon port have to operate efficiently. The purpose of this study is to help efficient operation of VTS in Inchon port by accomplishing both the literature research and questionnaire survey. Questionnaire survey was read to the VTS personnel in Inchon Port and customer familiar to Inchon Port such as ship navigators, pilots, shipping companies and so on. Most of ship navigators who occupy half of the respondents are Korean Officer who had responded while they were calling at Inchon port. The conclusions and recommendations includes ; First, the service area should be extended over Designated area to provide the vessel with navigational assistance service regarding the information of traffic congestion area, fishing boat and small ship's activities. Second, the types of information service to be offered are ship's movement and weather condition inthe vicinity of the port and state of fairway in the approaching channel to thte fairway. Third, VTS personnel should be upgraded by the on-the-job training and continuous simulation training as well as supplement of the qualified personnel for VTS operation. Fourth , the Harbor Master System to be introduced for safe navigation and efficient port operation.

• Journal of Microbiology and Biotechnology
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• v.14 no.5
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• pp.959-966
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• 2004

Twenty-three cultures of harmful algal bloom (HAB)-(causing dinoflagellates were isolated from the coastal waters of Korea. For each of the 14 morphospecies, the nuclearencoded small subunit (SSU) rDNA was analyzed to determine the phylogenetic relatedness of the species. Despite temporal and spatial isolation, 3-4 clonal cultures of Alexandrium catenella, Cochlodinium polykrikoides, and Gymnodinium catenatum had 100% identical SSU rDNA sequences. In contrast, heterogeneities in the SSU rDNA sequences were observed in Akashiwo sanguinea and Lingulodinium polyedrum strains. Extreme sequence polymorphism was shown within the SSU rRNA genes of an Al. tamarense clonal culture. A homology search in GenBank revealed that 11 dinoflagellate species were located in clusters corresponding to their morphological classification. The SSU rDNA sequences of C. polykrikoides, Gyrodinium instriatum, and Pheopolykrikos hartmannii, which were determined for the first time in this study, showed the following phylogenetic relationships: C. polykrikoides formed an independent branch separated from other dinoflagellates; Gyr. instriatum was placed in a monophyletic group with Gyr. dorsum and Gyr. uncatenum; and Ph. hartmanii, which forms a distinct two-celled pseudocolony, belonged to Gymnodinium sensu Hansen and Moestrup.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.15 no.2
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• pp.83-94
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• 1979

It is more than half a century since anchovy boat seine has been introduced in Korean fishery to catch anchovies, but the study on it was began in 1970's by the authors. In 1971, the authors carried out an experiment about the net formation of the traditional gear in tow by using model net, and in 1978, about the patti net gear, commercially used in Japan. Now, the authors investigated the new model net, model 79, expecting to be suitable for commercial fishery in Korea, with the strong point of those two gears kept and the weak point of them corrected. The experimental gear was constructed attached the long net pendants to the fore end of extension wing by shortening its length in two-third of the traditional gear. Inside wing was improved so as to show high opening in tow. Rubber bobbins and hanging rings are used to prevent the heavy friction of bosom ground rope against the sea bed. The gear was used to catch anchovies in the commercial fishing ground in the south-eastern coastal waters of Korea, from May to October in 1979. From the experiment, the following results are found. 1. In opening height, the experimented gear was 30 percent greater than the traditional one. 2. It took 3 to 5 minutes for the bosom ground rope to sink from the surface to the sea bed, while 10 to 15 minutes for the traditional gear to do. 3. Ground rope never scooped mud, even in the muddy sea bed. 4. The gear showed better catchability than the traditional gear.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.45 no.2
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• pp.77-84
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• 2009

This paper is to investigate the effect of the immersion time in the traditional hairtail hand line for developing the fishing methods and the fishing gear in the coast of jeju. The operating of 32 times was made with each different immersion time of hairtail hand line, and the relations between the catch and the immersion time were examined. As the result, targeted species rate was over 98% of total catch. From about 800 seconds after casting, the hooking rate was decreased and the bite loss rate was increased, it seems to be made by the decreasing factors of predators including the cutting of branch lines etc. In addition, it was supposed that the hooking rate and the bait loss rate had a deep connection with feeding time zone. The level of the correlation coefficient of the bait loss rate according to the immersion time was 0.54 at $p{\leq}0.01$, in the case of the hooking rate, 0.59 was chosen after about 800 seconds. The hooking rate and the bait loss rate according to the hook number were not irrelevant to the fish school layer. Additionally, it was assumed that the bait loss rate was related to the depth of water.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.45 no.3
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• pp.151-156
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• 2009

This study shows that the distribution density of snow crab, Chionoecetes opilio, was estimated using an underwater video monitoring system attached on the towing sledge. The field experiments were carried out at the coastal waters around Chuksan, East Sea, where ranged from 110 to 130m depth during September and October 2007. The sledge was towed for 40 minutes and the towing speed was controlled between 1.5 to 1.7 knot and each research areas were calculated to multiply towed distance by the detection width of the video monitoring system(1.2m), and then, distribution density of snow crab in each observations were estimated as a counted number of crab per 1,000$m^2$. The result shows that their survey, taken between two months, reflected similar results during survey period, and the maximum and mean distribution densities in September estimated to be 77.0(number/1,000$m^2$) and 19.9, respectively, and those of October were 36.0 and 21.8, respectively.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.45 no.2
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• pp.122-127
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• 2009

A series of fishing experiments was carried out in the eastern coastal waters of Korea from January, 2002 to March, 2003, using gill nets of different mesh sizes (m 180, 210, 240, 270 and 300 mm) to determine the size selectivity of gill net for female snow crab, Chionoecetes opilio. The catch of experimental gears was mostly snow crab (97%), Chionoecetes opilio. The maximum carapace length (RL) of each female snow crab caught in the fishing experiments was measured. The master selection curve was estimated by applying the extended Kitahara s method. The selection curve showed that the gill nets of larger mesh size allowed more female crabs of small carapace size to escape. The optimum values of RL/m for 1.0 of retention probability was 0.563 and RL/m was estimated to be 0.249, 0.290, 0.319, 0.344 and 0.367 when the retention probability were 0.1, 0.2, 0.3, 0.4 and 0.5, respectively.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.49 no.4
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• pp.368-376
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• 2013

Fishing experiments were carried out in the adjacent sea of Yeongil Bay, the eastern cost of Korea from 2003 to 2004 using the dome-shaped pots with different five mesh sizes (17.1, 24.8, 35.3, 39.8, and 48.3mm) in order to determine the size selectivity of pots for the whelk, Buccinum opisthoplectum. The catch species were composed of Buccinum opisthoplectum (45.4%), Buccinum striatissimum (30.1%), Pandalopsis japonica (9.3%), Chionoecetes opilio (8.9%), and so on. The shell height (l) of Buccinum opisthoplectum caught in the experimental fishing pots was measured. The SELECT (Share Each Length's Catch Total) analysis method was applied with fishing data to obtain master selection curve. The model with the estimated split parameter was found to fit the catch data best. The master selection curve was estimated to be s (R)〓exp (7.833R-10.871)/[1 + exp (7.833R-10.871], where R is the ratio of shell height to mesh size. The relative shell length for 50% retention was 1.388, and the selection range was 0.281. It means that the pots of larger mesh size allow more whelks of small size to escape.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.49 no.4
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• pp.352-359
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• 2013

To estimate the mesh selectivity of gillnet for ocellate spot skate (Okamejei kenojei), the field tests were carried out 12 times with six different mesh sizes (121.2mm, 137.7mm, 151.5mm, 168.3mm, 178.2mm, 189.4mm) in the coastal waters of Taean, Chungcheongnamdo of Korea, 2010~2011. In the field tests, the total number of species was 31, and that of catch was 1,410 and the total weight was 618,006g. The number and weight of ocellate spot skate which is main target in this study were 1,004 and 434,592g, respectively. The catch in number of ocellate spot skate occupied about 71.2% in total catch. The others of catch species were marbled sole (8.4%), sea raven (4.4%), japanese swimming crab (4.2%) and flatfish (4.1%) and so on. The range of body disk width (DW) of ocellate spot skates which were caught in this study was 15.2~35cm and the mode was 27~29cm. The estimation equation of mesh selectivity using the extended Kitahara's method was expressed as s $(R)=s(DW/m)={\exp}\{(-0.56R^3-1.80R^2+12.96R-9.99)-4.26\}$. The optimum value of DW/m for 1.0 of retention probability in this estimation equation was estimated 1.899 and DW/m was estimated to be 1.194, 1.314, 1.395, 1.461 and 1.520 when the retention probability were 0.1, 0.2, 0.3, 0.4 and 0.5, respectively. When applied to the retention probability of 0.5, the optimum mesh size was estimated to be 177.0mm on first maturity disk width 26.9cm of ocellate spot skate.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.53 no.1
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• pp.41-48
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• 2017

Encircling gill net fishery is a kind of gill net which is generally used in shallow coastal waters. After the fish have been encircled by the gill net, noise stimulus such as a stone or sound is used to force them to gill or entangle themselves in the netting surrounding them. Although the fishing by a stone is a traditional fishing method, it is considered as an illegal fishing method by physical stimulus such as explosives and mechanical vibrator. However, this illegal fishing method has raised some problems to the fishing boat of other fisheries or many anglers due to disturb aggregating fish schools. This study is aimed to provide scientific base data to verify whether to impact the ecosystem caused by this encircling gill net. This study exhibited that the impulse noise by concrete sphere in the encircling gill net was $159dB/{\mu}Pa$, the ambient noise from ship engine was $160dB/{\mu}Pa$, and the maximum noise from continuous artificial vibrator was $175dB/{\mu}Pa$. These may be stimulus to the escape of fish distributed in a wide area in its natural state; it is not likely the cause of death due to catastrophic stress. Therefore, it needs to prepare the consideration of standard limit on fishing stimulus in fishing methods of the fishery laws and regulations, prevent fishermen form using illegal fishing gear (i.e. explosive sound standards: $200{\sim}220dB/{\mu}Pa$ and provide them with countermeasures.

• Proceedings of KOSOMES biannual meeting
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• 2006.05a
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• pp.47-52
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• 2006

The cultural grounds of laver has been surveyed using SPOT-5 satellite images to calculate the facilities of laver cultivation area in the coastal waters of Korea 10m resolution multispectral images of SPOT-5 are adopted for the south area of Daebu Island, Hwaseong city to develop an automatic detection approach of laver nets that consists of the following: band difference technique, canny edge detector and morphological analysis. The satellite-based facilities number was relatively high as compared with the licensed number in 2005, 676,749 chaek and 572,745 chaek(柵, unit of measure for laver farm), respectively. The data could be applied to achieve a good harvest for laver seaweed growers and to control its national production keeping a stable market price for the government body.