• 한국수산과학회지
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• 제38권4호
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• pp.245-250
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• 2005

The maturity and spawning of Pacific cod, Gadus macrocephalus, was studied using samples caught by gillnets in the East Sea from January to December 2003. Monthly changes of maturity observed with the naked eyes for females showed that maturing Pacific cod appeared from August, and their numbers increased to $83\%\;and\;100\%$ in November and December, respectively. In January, mature and spawning Pacific cod were observed for the first time and composed over $40\%$ of the population. In February, the proportion of spawning individuals increased to over $50\%$, however, the mature individuals decreased to less than $10\%$. In March, mature fish were not found, and all were in an immature (spent) or spawning state. From April to July all fish remained in immature condition. The males maintained this trend with the females, whereas, mature males appeared from November to March. Monthly changes in the gonadosomatic index (GSI) of females and males showed higher values both in January and February and declined sharply in March. The lower value remained until October and then began to increase from November for the female population. For the males, however, this value remained lower until August, and then began to increase from September, and showed higher values in October through December than in January and February. These results indicated that the spawning season of Pacific cod was from December to March, and the main spawning season was from January to February, and the period of the spawning season was longer for males than the females. The diameter of the matured oocytes was 0.80-1.10 mm with a single mode of 0.95 mm. Fecundity was 1,300,000-9,400,000 in total length of 65-95 cm and the relationship between the total length (TL, cm) and fecundity (Fc) was Fc= $180,248\timesTL-10,883,638$. The total length at first maturity was observed at 57 cm for females and 47 cm for males. The size at $50\%$ group maturity was estimated to be 63.9 cm for females and 56.0 cm for males.

• 한국해양학회지:바다
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• 제26권4호
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• pp.307-326
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• 2021

상시 관측되는 조위관측소 해수위 자료는 결측값과 오측값을 포함하고 있으며, 그 중 오측 값은 이상값으로 분류되는 전처리 대상이다. 이러한 오측을 제거하기 위해 대표적으로 3𝜎 (three standard deviations) 규칙이 적용되어왔으나, 기상이변 등에 의한 극값이 존재하거나 3𝜎 범위 안에서도 오측이 존재하는 해수위 자료에는 그 적용이 어렵다. 본 연구에서 설계된 모델은 오측에 대한 사전 정보가 필요하지 않은 비주석 학습으로 구성되며, 재귀신경망과 앙상블 기법을 이용함으로써 실시간으로 수집되는 해수위 자료가 오측일 가능성을 발생한지 20분 이내로 제시한다. 검증이 완료된 모델은 평시 및 기상이변시의 정상값과 오측값을 잘 분리하며, 학습이 이뤄지지 않은 연도의 해수위 자료에서도 이상값 탐지가 가능함을 확인하였다. 본 연구의 관측 이상치 탐지 알고리즘은 조위관측소 해수위에 국한되지 않고 다양한 해양 및 대기자료의 이상치 탐지 인공신경망 모델에 확장 적용할 수 있다.

• 한국항만경제학회지
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• 제22권3호
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• pp.189-207
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• 2006

동북아 물류허브의 건설이 국가전략으로 들어서면서 물류분야에 대한 관심이 제고되자, 환황해권을 배경으로 한 해공복합운송에 대한 관심도 고조되고 있다. 해공복합운송은 항공운송의 신속성과 해상운송의 저렴성을 결합한 틈새시장으로서의 성격을 갖는 것이다. 따라서 현재 진행되고 있는 해공복합운송의 향후 가능성을 확인하는 것은 중요한 연구과제 중 하나이다. 본 연구는 이러한 문제의식 하에서 환황해권 해상복합운송의 향후 발전 가능성을 경쟁력 측면, 장래수요 측면, 그리고 기술조건 및 수송환경의 변화 측면에서 검토하였다. 그 결과, 경쟁력 측면에서는 시간이나 비용 등 모두에서 현재 상태에서는 충분한 경쟁력이 있고, 장래수요 측면에서도 지속성의 여지는 있으나, 기술조건의 변화나 수송환경의 변화측면에서 안정성은 높지 않은 것을 확인하였다. 특히 항공기술의 발전에 따른 중소도시직항형태의 항공환경 변화, 중국 항공사를 겨냥한 국제 항공사들의 전략적 제휴 등은 해공복합운송의 향후 발전에 중요한 위협요인이 될 것으로 분석하였다. 이에 본 연구는 향후 해공복합운송의 발전을 위해 현재 진행되고 있는 환적화물 중심의 해공복합운송이 부가가치창출형 해공복합운송으로 발전되어 수요의 안정성을 높이고, 또 더 나아가 동북아 SCM 허브형 해공복합운송을 지향함으로써 수요창조형으로의 비전을 가져야 함을 향후 대안으로 제시하였다.

• 환경영향평가
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• 제12권5호
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• pp.369-382
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• 2003

Natural resources managers have considered the landscape without detailed consideration of aesthetic values of the landscape and geomorphological significance of unique landforms. Since EIA system was introduced in 1981, values associated with landscape protection have been neglected at best compared with those values traditionally attributed to environmental protection, including clean air, water quality and species protection. Black top highways are being built without consideration of harmful effects to the sea cliffs. Sea walls and tetrapod are being installed to protect the coastal towns and fish markets for tourist. However, beach itself are experiencing accelerated erosion due to the shortage of proper coastal engineering expertise. Hotels and condominiums are under construction on a massive scale around the national parks, which substitute the scenic ridges with concrete profiles. To protect the scenic beauty of national parks, their design and construction material should be more harmonious with the surroundings. Therefore, visual impact assessment should be applied both within the national park boundary and beyond to enhance the aesthetic values of national parks.

• Journal of Astronomy and Space Sciences
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• 제17권2호
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• pp.295-308
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• 2000

OSMI(Ocean Scanning Multi-Spectral Imager) raw image data(Level 0) were acquired and radiometrically corrected. We have applied two methods, using solar & dark calibration data from OSMI sensor and comparing with the SeaWiFS data, to the radiometric correction of OSMI raw image data. First, we could get the values of the gain and the offset for each pixel and each band from comparing the solar & dark calibration data with the solar input radiance values, calculated from the transmittance, BRDF (Bidirectional Reflectance Distribution Function) and the solar incidence angle($\beta$, $\theta$) of OSMI sensor. Applying this calibration data to OSMI raw image data, we got the two odd results, the lower value of the radiometric corrected image data than the expected value, and the Venetian Blind Effect in the radiometric corrected image data. Second, we could get the reasonable results from comparing OSMI raw image data with the SeaWiFS data, and get a new problem of OSMI sensor.

• 한국농공학회논문집
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• 제55권2호
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• pp.1-8
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• 2013

This study was performed for the purpose of analyzing the effect of tide on the stress-strain behavior in the boundary surface of sea dike embankment. Tide is a dynamic condition, but there are not suitable numerical models to solve the dynamic embankment condition caused by tide. So the analysis was simplified to quasi dynamic as follow. First, seepage by tide was analyzed according to elapsed time, and the results of the analysis at every hour during one periodic cycle time of 12 hours were applied to the pore water pressure conditions of stress-strain analysis with hyperbolic model by Duncan and Chang. The place at which maximum shear strain took place in the analysis result moved up and down repeatedly along the boundary of the dredged sand fill section and the crashed stone filter section. The value of maximum shear strain was large at high water level of tide. This result means that contraction and relaxation occur in turn repeatedly at every specific position along the boundary, and the repeated action compact loose position with sand moved down from the upper position by gravity. The experiment with the small sea dike model showed the result consistent with the numerical analysis. The surface of sea side on the dike collapsed at high water level after a couple of repetition of the rising and falling of water.

• 수산해양기술연구
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• 제49권1호
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• pp.1-17
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• 2013

The investigation for species composition and catch in the Korean deep-water of the East Sea (also known as Sea of Japan) was carried out with trammel nets of 7 mesh sizes (6.1~24.2cm) offshore Donghae (2006) and Yangyang (2007) of Korea. The catches were 1,268kg and composed of 37 species between 200m and 1,200m in depth. The principal species caught were Taknka's snailfish, salmon snailfish, red snow crab, hunchback sculpin, snow crab, spinyhead sculpin, Tanaka's eelpout, Alaska cod and so on. Those were target fish for commercial value except salmon snailfish. The mesh sizes for the largest catch were 10.6cm and 15.2cm in the fishing ground of Donghae and Yangyang, respectively. The habitat of snow crab was shallower than that of red snow crab in both areas. Trammel net enabled to investigate fish in deep-water with small fishing vessel and rather cheap expenses in contrast to bottom trawl that required too much of it. With increasing inner mesh size of trammel net the mean size of some principal species such as Taknka's snailfish, spinyhead sculpin, hunchback sculpin, Pacific cod, snow crab, red snow crab and hybrid between snow crab and red snow crab tended to be large in certain range of mesh size.

• 대한조선학회논문집
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• 제29권1호
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• pp.113-122
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• 1992

선박소음을 예측하는 과정중에서 고체소음 전달해석은 직접적으로 예측결과의 정도에 영향을 미치고 있다. 이에 대한 계산 방법으로서 경험식이 그 간편성 때문에 자주 사용되고 있지만 자체의 한계성 때문에 이론적 해석방법(Wave guide theory, SEA등)들에 대한 연구가 선박음향학 분야에서 꾸준히 수행되어 왔다. 본 연구에서는 SEA를 이용하여 22개의 plate로 구성된 선체구조의 단순모델을 대상으로 고체소음 전달손실에 대한 이론적 계산 및 실험적 산정을 수행하였다. 계산치와 실험치의 비교결과는 3 dB이내의 좋은 일치를 보여 주었다.

• 무역상무연구
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• 제70권
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• pp.67-80
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• 2016

As China, the world's work shop was transformed into consumption market intermediary products and expensive consumer goods are more in highly demand recently. These will tend to diffuse especially to the west coastal cities of China. The economic growth of China needs to develop hub port facilities more and more in these days. We don't need to explain value of hub port in international trade. Furthermore If we are to retain access convenience of merchant vessel we really must maintain hub ports in Korea. This paper aims to vitalize Pyeongtaek port in times of the Pan Yellow Sea in readiness for an increase of trade between Korean, China, and Japan absorbing economic effects. The Rise of China leads to increase of trade of Korea that make necessary to develop a big and wide port to Pan Yellow Sea times. There is a lot of competition to be a hub port to become a center of international trade in the Pan Yellow Sea market. We need to improve the surrounding environment or facilities and industry clusters flexibly of Pyeongtaek port. It will guide to cost cutting and to raise business efficiency. Ultimately Pyeongtaek port should maintain and make advance its competitiveness especially in the Pan Yellow Sea times.

• 한국해양학회지
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• 제6권2호
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• pp.99-103
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• 1971

GEK(Geomagnetic Electrokinetograph)가 개발되고 그에 대한 취급의 간편, 측정의 용이, 정도의 우수성으로 GEK를 이용한 많은 관측이 수행되고 또 그들 자료를 바탕으로 많은 연구에 임하고 있어, 지금은 해양관측에 있어 필수의 기계로서 이것으로 해류조사를 행한다고 하는 것은 널리 알려진 바이다. 그러나 여기에서는 " 사쓰난"(살남) 해역 (일본 구주 남서방해역)과 같이 조석류와 복잡한 해저지형 및 대소다양한 도서의 분포 등으로 영향 받는 해역에서의 GEK 측정은 타해역 (일본 본주 남방의 흑조류역 등)에서 행하여지는 것 같이 쉽지 않다고 볼 수 있다. 여기에 일본 사쓰난해역에서 조사된 GEK의 측득치에 대하여 검토하였다.대하여 검토하였다.