• 수산해양교육연구
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• 제19권2호
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• pp.180-196
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• 2007

This study aims at analyzing the potential of leports-fishing for improving fishing household income. Leports-fishing is a composite concept which is combined with those of leisure, sports and fishing. Korean on-shore resources have also a composite characteristic. The properties of the east, west and south coastal waters are quite different in geography, biology and ecology. There is a array of leports-fishing development potentials of utilizing their characteristics. At present, angling forms a main activity of leports-fishing, but coastal seas would be an emerging space for the public. In order for them to be a ground of fun, enjoyment and festivals, it would be necessary to supply a wide range of activities and facilities including angling, scuba diving, fish barbecue, ecological experience, fishing experience, cruise, and so forth. As seen in the survey results, the participants have strong desire for fun and enjoyment through leports-fishing activities. The proportion of people participating in one or two times a year amounts to 40 percent. Most coastal places visited are close to medium/large cities and two-days leports-fishing/tourism accounts for some 77 percent. However, it turned out that conflicts between leports-fishing participants and fishermen are not serious. The results of expenditure function estimation appear that the elasticity of per capita income is very high with 1.2660 and that there are negative relationships between leports-fishing expenditure and transportation/food/lodging costs. Assuming the annual national economic growth rate of 4 percent, it is anticipated that Korean leports-fishing population will increase to 3.18 million in 2010 and 4.07 million in 2015. Korean leports-fishing market potential in 2015, which is calculated based on per capita expenditure on leports-fishing, appears to amount to 1,400 billion won~1,600 billion won. The contribution of such market potential to the fishing households is expected to be 62.3~74.2 percent(934.5 billion won~111.3 billion won).

• Ocean and Polar Research
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• 제33권1호
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• pp.69-76
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• 2011

A test miner named MineRo was constructed for the purpose of shallow water test of mining performance. In June of 2009, the performance test was conducted in depth of 100 m, 5 km away from Hupo-port (Korean East Sea), to assess if the developed system is able to collect and lift manganese nodules from seafloor. In August of 2010, in-situ test of automatic path tracking control of MineRo was performed in depth of 120 m at the same site. For path tracking control, a localization algorithm determining MineRo's position on seabed is prerequisite. This study proposes an improved underwater navigation algorithm through estimation of MineRo's kinematic parameters. In general, the kinematic parameters such as track slips and slip angle are indirectly calculated using the position data from USBL (Ultra-Short Base Line) system and heading data from gyro sensors. However, the obtained data values are likely to be different from the real values, primarily due to the random noise of position data. The aim of this study is to enhance the reliability of the algorithm by measuring kinematic parameters, track slips and slip angle.

• Ocean and Polar Research
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• 제24권4호
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• pp.407-417
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• 2002

Species composition and abundance of zooplankton were investigated around Dokdo in the East/Japan Sea in autumn 1999 and spring 2000. Vertical and horizontal hauls of a bongo net ($300{\mu}m$ mesh size, 60cm diameter) were made to collect zooplankton sample. Surface temperature and salinity ranged from $24.2^{\circ}C\;to\;25.1^{\circ}C$, and from 32.9psu to 33.2psu in September 1999, respectively. In May 2000, surface temperatures were $13.9^{\circ}C\;and\;14.2^{\circ}C$ at stations of A1 and A8, and salinity was 34.5psu at both stations. Zooplankton community was dominated by copepods which comprised 61% (September) and 60% (May) of total numerical abundance, respectively. The next dominant groups were appendicularians (11%) and chaetognaths (9%) in September 1999, and other crustaceans (27%) and appendicularians (4%) in May 2000. The 15.7% (September) and 23.2% (May) of copepods were in the juvenile stage of copepodites. The most dominant copepods were Oncaea media (10.4%) and Clausocalanus sp. (8.2%) which preferred warm water in September. In contrast, cold-water copepods such as Pseudocalanus minutus (9.4%) and Metridia pacifica (8.0%) were dominant in May. The results of cluster analysis based on Bray-Curtis index showed that zooplankton community were classified into two groups which represented different water mass. The average abundance of zooplankton in September was 2.1 times higher than that in May, and species number of them in September outnumbered that in May by 29 species. Zooplankton community varied in associated with a characteristic of warm waters which affected marine ecosystem differently in the study area depending on seasons.

• 대기
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• 제27권4호
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• pp.455-466
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• 2017

In Korea, property and human damages occur annually due to heavy precipitation during the summer. On August 8, 2015, heavy rainfall occurred in the Seoul metropolitan area due to an outflow boundary, and $77mmhr^{-1}$ rainfall was recorded in Gwangju, Gyeonggi Province. In this study, the simulation of the WRF numerical model is performed to understand the cause and characteristics of heavy rainfall using the Conditional Instability of the Second Kind (CISK), potential vorticity (PV), frontogenesis function, and convective available potential energy (CAPE) analyses, etc. Convective cells initiated over the Shandong Peninsula and located on the downwind side of an upper level trough. Large amounts of water vapor were supplied to the Shandong Peninsula along the southwestern edge of a high pressure system, and from the remnants of typhoon Soudelor. The mesoscale convective system (MCS) developed through CISK process and moved over to the Yellow Sea. The outflow boundary from the MCS progressed east and pushed cold pool eastward. The warm and humid air over the Korean Peninsula further enhanced convective development. As a result, a new MCS developed rapidly over land. Because of the latent heat release due to convection and precipitation, strong potential vorticity was generated in the lower atmosphere. The rapid development of MCS and the heavy rainfall occurred in an area where the CAPE value was greater than $1300Jkg^{-1}$ and the fronto-genesis function value of 1.5 or greater coincided. The analysis result shows that the MCS driven by an outflow boundary can be identified using CISK process.

• 생명과학회지
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• 제18권6호
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• pp.897-901
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• 2008

해양심층수(deep seawater, DSW)는 청정성과 무기물질의 풍부함 때문에 여러 분야에 응용하기 위하여 최근 많은 관심을 받고있다. 본 연구에서는 동해 양양 부근의 해저 1,100 m에서 취수하여 역삼투압 시스템으로 탈염과 농축을 한 심층수가 배양한 흰쥐해마신경세포의 형태적 분화에 미치는 영향을 조사하였다. 10%(v/v) fetal bovine serum이 첨가된 MEM 배지에서 키운 세포와 비교할 때 25%(v/v) DSW이 포함될 경우 배양 17시간째에는 차이가 없었다. 그러나 DIV3, 7, 14, 및 17에 관찰하면 경도 0 및 200의 DSW가 포함된 배지에서 자란 신경세포는 가지돌기의 수가 현저히 줄었다. 반면에 경도 600의 DSW에서 자란 신경세포는 그 가지돌기의 수가 대조군과 비슷하였으며, 경도 1000의 경우는 대조군에 비하여 거의 2배 증가하였다. 이 결과는 적당한 경도의 DSW는 신경세포의 성장 및 건강을 돕는 것으로 해석된다.

• 수산해양기술연구
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• 제49권2호
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• pp.116-125
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• 2013

Jigging and angling fishery is prevalent in the East Sea of Korea and this fishery needs many lamps to attract the fish. And the fishing boat uses 24~47 ballasts by the vessel's tonnage to turn on the fishing lamp. A 3.5kW magnetic-type ballast being currently used at many fishing boats can drive two 1.5kW metal-halide lamps. Meanwhile, this ballast has large weight (25kg) and volume. Therefore it is one of reason for the over-consumption of energy and the fire, resulted from overheat and electrical short, occurs occasionally because the ballast is installed at narrow and hot engine room. In addition, most of magnetic ballast has several problems such as periodic condenser replacement, low energy efficiency and making lamp short life, etc. So it is necessary to improve or develop newly the electronic ballast, which has to be smaller, lighter and more efficient. An electronic ballast was designed for the fishing boat by considering duration and electromagnetic interference in the study. Its weight and volume are respectably 40% and 66% compared to current ballast on the basis of PCB. The metal-halide lamp's spectrum of the designed ballast was nearly same to that of the current ballast in the test of lighting. In particular, the light stability was improved and there isn't any radio interference. As mentioned above, it is expected that the developed electronic ballast can replace current magnetic ballast because of many advantages related to energy-saving.

• 한국수산과학회지
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• 제39권5호
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• pp.419-426
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• 2006

This study investigated the ecology and growth of Monostroma nitidum Wittrock in both its natural habitat and the laboratory. The maximum length, width, and weight of M. nitidum in March were 9.0$\pm$4.7 cm, 9.6$\pm$3.6 cm, and 1.52$\pm$1.13 g, respectively. Yellowish-green or yellowish-brown reproductive thalli began to appear in January, and over 80% of the thalli matured by March. The male and female spores were ca. 6 $\mu$m long, and elongate and ovoid in shape. The spores had two flagella and one-eye spot, and tended to swim toward light. Maximum number of spores released from matured thalli was 236 cells/mL after 70 minutes at a light intensity of 100 $\mu$mol/m$^2$/s. The zygote diameter ranged from 3.4-6.0 $\mu$m (mean 4.2 $$m) and increased to 69.8 $\mu$m 14 weeks after culture. The mass release of zoospores was observed from thalli in the dark (3 to 12 days), after 30 min under dry conditions in the shade, at 25$^{\circ}C$, and a light intensity of 100 $\mu$mol/m$^2$/s. The maximum number of zoospores released was 109.8 cells/mL after 60 min of induction. M. nitidum fronds on the net increased to 6.8-7.2 cm in length, and 6.6-8.9 cm in width during the winter.

• 대한지리학회지
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• 제37권3호
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• pp.222-236
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• 2002

태백산맥 동사면을 흘러 직접 동해로 유입하는 삼척 오십천의 중.하류부 하안단구는 기후단구와 해면변동단구로 구분된다. 기후단구는 5단이 확인되며, 해면변동단구는 해발고도 145-150m까지 7단의 지형면이 20-30m 간격으로 분포한다. 이와 같은 해면변동단구의 수직적 분포특징은 지반의 지속적인 융기와 기후변화에 의한 빙기와 간빙기의 해면승강작용의 결과이다. 해면변동단구 고고위면은 한반도에서 현재까지 보고된 가장 높은 해안단구보다 해발고도가 더 높다. 해발고도 40m에 분포하는 해면변동단구는 marine oxygen isotope stage 7, 해발고도 70m인 해면변동단구는 stage 9, 해발고도 90m인 해면변동단구는 stage 11, 해발고도 110m 지형면은 stage 13, 해발고도 150m 지형면은 stage 15의 간빙기에 형성된 것으로 추정된다. 중위면, 고위면과 고고위면에는 doline와 함께 uvala와 같은 카르스트지형이 발달하고 있으므로 토지이용과 지형경관이 특징적이다.

• ALGAE
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• 제23권4호
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• pp.327-334
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• 2008

Seaweed biomass was estimated using a nondestructive sampling method in the rocky intertidal and subtidal zone in Daejin on the mid-east coast of Korea from August 2006 to April 2008. Seasonal sampling were done at the depth of 0, 1, 5, 10 m using 50 x 50 cm quadrat. A total of 95 species, including 11 chlorophytes, 26 phaeophytes, 57 rhodophytes and one sea grass were identified. Mean biomass was comprised of 1,292 g wet wt m$^{-2}$ and the biomass values varied seasonally from 904 g to 1,945 g. Dominant species in biomass were Sargassum spp. (S. horneri, S. yezoense), Corallina pilulifera, Phyllospadix japonica, Symphyocladia latiuscula, Hizikia fusiformis, Codium arabicum and Chondrus ocellatus at Daejin. The vertical distribution of algae were characterized by Corallina pilulifera, Symphyocladia latiuscula, Sargassum spp. (S. confusum, S. yezoense), Hizikia fusiformis and Grateloupia elliptica at intertidal zone, Sargassum spp. (S. fulvellum, S. horneri, S. yezoense), Phyllospadix japonica, Codium arabicum, Undaria pinnatifida and Corallina pilulifera at 1 m depth, Sargassum spp. (S. horneri, S. micracanthum, S. yezoense), Phyllospadix japonica, Grateloupia elliptica, Gelidium amansii and Codium arabicum at 5 m depth and Phyllospadix japonica, Codium arabicum, Sargassum spp. (S. horneri, S. micracanthum, S. yezoense) and Undaria pinnatifida at 10 m depth.

• 한국수산과학회지
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• 제51권6호
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• pp.704-713
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• 2018

Globally, the survival of many marine mammals is threatened by entanglement in fishing gear and there is also a high bycatch in Korea. This study analyzed the bycatch data of most cetacean species for Korean waters from 2011 to 2017, including the narrow-ridged finless porpoise Neophocaena asiaeorientalis, common dolphin Delphinus delphis, common minke whale Balaenoptera acutorostrata, and Pacific white-sided dolphin Lagenorhynchus obliquidens. A total of 12,262 cetaceans were captured as bycatch. In the Yellow and South Seas, the main species affected was the narrow-ridged finless porpoise, with 82.9% caught in stow nets and 11.5% captured in trawls. In the East Sea, the common minke whale, common dolphin, and Pacific white-sided dolphin were reported. The main common minke whale bycatch (43.5%) was in set nets, while common dolphins (49.0%) and Pacific white-sided dolphins (91.4%) were mainly caught in gill nets. The narrow-ridged finless porpoise, common dolphin, and common minke whale were most commonly reported in March, April, and May, while the Pacific white-sided dolphin was most frequently captured as bycatch in January and December. Each of these factors (season and gear responsible for bycatch) depended on the characteristics of the cetacean species. To conserve cetaceans, it is necessary to reduce the bycatch.