• Korean Journal of Remote Sensing
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• v.39 no.5_1
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• pp.695-713
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• 2023

In coastal waters, phytoplankton,suspended particulate matter, and dissolved organic matter intricately and nonlinearly alter the reflectivity of seawater. Neural network technology, which has been rapidly advancing recently, offers the advantage of effectively representing complex nonlinear relationships. In previous studies, a three-stage neural network was constructed to extract the inherent optical properties of each component. However, this study proposes an algorithm that directly employs a deep neural network. The dataset used in this study consists of synthetic data provided by the International Ocean Color Coordination Group, with the input data comprising above-surface remote-sensing reflectance at nine different wavelengths. We derived inherent optical properties using this dataset based on a deep neural network. To evaluate performance, we compared it with a quasi-analytical algorithm and analyzed the impact of log transformation on the performance of the deep neural network algorithm in relation to data distribution. As a result, we found that the deep neural network algorithm accurately estimated the inherent optical properties except for the absorption coefficient of suspended particulate matter (R² greater than or equal to 0.9) and successfully separated the sum of the absorption coefficient of suspended particulate matter and dissolved organic matter into the absorption coefficient of suspended particulate matter and dissolved organic matter, respectively. We also observed that the algorithm, when directly applied without log transformation of the data, showed little difference in performance. To effectively apply the findings of this study to ocean color data processing, further research is needed to perform learning using field data and additional datasets from various marine regions, compare and analyze empirical and semi-analytical methods, and appropriately assess the strengths and weaknesses of each algorithm.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2004.11a
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• pp.13-16
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• 2004

Deep sea water has mid temperature, abundant nutrients and minerals, and good tooter quality. For the purpose of drawing up deep sea water without pump pit construction, tile authors are considering to use air-lift pump. This report describes fundamental experimental investigation for air-lift pump characteristic and improvement in efficiency.

• Proceedings of KOSOMES biannual meeting
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• 2017.04a
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• pp.273-274
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• 2017

선원의 다국적화가 이루어짐에 따라서 해기사들의 외국인 선원관리에 대한 리더십이 날로 중요시 되고 있다. 효과적인 리더와 리더십은 교육을 통해 양성되고 향상될 수 있다. 본 연구는 선원의 다국적화가 증가되고 있는 현실을 감안하여 해기사 양성 대학의 리더십 교육체계 정립을 위한 기초연구로서, 학생들이 실습시 경험한 자료를 토대로 설문 분석을 하였다. 향후 확대된 자료의 수집과 심층분석을 통해 지속적으로 심층 연구를 하고자 한다.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.2
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• pp.235-244
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• 2011

The physicochemical properties and quality changes in salted and dried brown croaker products using deep seawater salt were investigated for preparation with different pretreatment, salting and drying conditions. Optimum salt concentration, salting time and drying time for product were 20% of body weight, 12 hrs at room temperature ($25{\pm}2^{\circ}C$), and 24 hrs at $30{\pm}2^{\circ}C$, respectively. The volatile basic nitrogen (VBN), peroxide value (POV), viable cell count and acid value (AV) of viscera and blade removed products were 18.9~22.4 mg%, 21.0~32.5 meq/L, and 2.3~4.4 mg/mL, $2.0\sim3.5{\times}10^3$ CFU/g, respectively and only viscera removed products were 31.2~38.1 mg%, 40~55.2 meq/L, 7.0~11.5 mg/mL, $4.1\sim5.5{\times}10^3$ CFU/g, respectively. Changes in quality of salted and dried brown croaker products were investigated during storage at room temperature and $5{\pm}2^{\circ}C$. The POV, AV and viable cell counts of salted and dried brown croaker products increased in commercial salt used and only viscera removed products compared with deep seawater salt used and viscera and blade removed products during storage time. Results in this study showed that the deep seawater salt was very effective for quality control of salted and dried brown croaker products and pretreatment method was a very important factor for preparation products. The optimum conditions for preparation of salted and dried brown croaker product were 20% of body weight for salt concentration, 12 hrs at $25{\pm}2^{\circ}C$ for salting time, and 24 hrs at $30{\pm}2^{\circ}C$ for drying time. Optimum storage time for quality maintenance was 14 days at $5{\pm}2^{\circ}C$.

• Journal of the Korean Solar Energy Society
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• v.29 no.2
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• pp.14-21
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• 2009

Recently, alternative energy resources have emerged considerably due to the high oil prices and environment problems. Deep sea water that is one of the natural energy sources can be one of the attractive solutions to reduce the environment problems, and there are already a few examples in some developed countries. In this study, cooling system of deep sea water using heat exchangers of two hotels, located in near Haeundae Bay in Busan, have been analyzed on the quantity of electricity and gas use comparison between existing cooling system and deep seawater cooling system by using E-Quest simulation program. The results of the study showed that the Hotel A approximately saves 370 millions won per year, and the Hotel B saves 248 millions won per year. It means that the cooling system by using deep sea water has great worth to reduce the ratio of fuel sources.

• Proceeding of EDISON Challenge
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• 2016.03a
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• pp.576-581
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• 2016

해양환경에서 큰문제가 되고 있는 아주 작은 크기의 플라스틱 입자인 미세플라스틱(Microplastic)은 잔류성이 크고 생물축적성이 있는 잔류성 유기오염 물질(POP)을 잘흡착하여 해양환경과 먹이사슬에 지대한 피해를 끼친다. 본 연구에서는 해양에 존재하는 대표적인 미세플라스틱 uPVC와 입자상의 잔류성 유기오염 물질 PAH를 원형 실린더로 가정하여 해양 환경에서 침강하고 있는 미세플라스틱이 잔류성 유기오염 물질에 의해 오염될 가능성을 알아보았다 이를 위해 표층및 심층수 환경에서 반지름에 따른 충돌효율과 접촉 시간을 구하여 두 실린더가 접촉할 시간의 기댓값인 기대 접촉시간을 계산하였다.

• Proceedings of KOSOMES biannual meeting
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• 2004.11a
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• pp.117-122
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• 2004

In order to investigate the initial stage of deep water formation between Vladivostok and the subpolar front in the East Sea, the factors, temperature, salinity, dissolved oxygen, measured by multi-ship surveys in 1969 have been used Deep water formation in the East Sea occurs in essentially two different forms: near continent and open ocean formation the position of eddy derived from potential vorticity matches well with that of deep water formation. The vertical and horizontal distributions of potential vorticity, geostrophic current, temperature, salinity and dissolved oxygen give clues for the preconditioning phase of open ocean formation like a doming of isotherm, associated with a cyclonic circulation

• Journal of the Korean Society for Marine Environment & Energy
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• v.15 no.1
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• pp.9-18
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• 2012

Annual power consumption of our country is positioned in the upper percentile in the world, and because the proportion of fossil power generation is high, which ranks the 10th $CO_2$ emission country. In this regard, government has established and is implementing the National Energy Basic Plan to realize to get out of fossilization in energy supply while focusing on securing the technology for renewable energy as well as its commercialization in order to reduce greenhouse gas. Resource recovery technology for deep seawater thermal energy which is one of renewable energies is newly getting attention domestically as well as in overseas for securing resources and environmental improvement as a core technology for multilateral use of marine resources for low carbon and green growth. Economic feasibility analysis was conducted for the research and development as follows on the use of ocean thermal energy conversion and seawater air conditioning. First, in the case of power generation using deep seawater and warm discharge water from ocean thermal energy conversion plant of 1MW level, it is judged that the economic feasibility is insufficient but the feasibility will be significantly improved if we consider not only power generation but also drinking water and certified emission reduction by developing the power plant to the size for commercialization. Second, the economic feasibility for the use of deep seawater as air conditioning for the power plant of 1,000RT level turned out to be very good. Especially, when we consider certified emission reduction, it will be possible to secure sufficient economic feasibility. When we use it in connection with ocean thermal energy conversion, water conversion and agricultural and fishery use, it is judged that economic ripple effect will be significant and therefore it will be necessary to conduct research and development for early commercialization, distribution and diffusion of deep seawater energy.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.27 no.2
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• pp.113-117
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• 2015

This study presents a 3-dimensional flow-structure interaction analysis of subsea risers in water flows. Two structural connectors (flat and circular couplers) were intentionally devised and numerically tested using ANSYS CFX to investigate how these couplers behave under the water flows. In the flow analysis, the water field was constructed with an inlet, outlet, and symmetric boundary conditions. As a result, the responses (drag coefficients and pressure fields) were obtained and the pressure fields were applied for the structural analysis. Finally, the structural responses (displacements and equivalent stresses) of the risers were measured to demonstrate the efficiency of the riser connectors.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.1279-1284
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• 2008

The alternative energy has lately attracted considerable attention due to the high oil price and environment problem. Deep sea water that is one of the natural energy sources should be getting popular continually to reduce the environment problem. In this study, cooling system of deep sea water using heat exchangers of two hotels where is located in near Hae-undae Bay has been analyzed on the quantity of electricity comparison between existing cooling system and deep seawater cooling system. As shortly, the results of study showed that the first building approximately saves 370 millions won per year, also the second building saves 248 millions won per year. It means that the cooling system by using deep sea water has great worth to reduce the ratio of fossil fuel.