• Title/Summary/Keyword: ocean

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Performance Analysis of Ocean Thermal Energy Conversion on Working Fluid Classification (작동유체에 따른 온도차발전사이클의 성능 해석)

  • Lee, Ho-Saeng;Moon, Jung-Hyun;Kim, Hyeon-Ju
    • Journal of Power System Engineering
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    • v.20 no.2
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    • pp.79-84
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    • 2016
  • The thermodynamic performance of ocean thermal energy conversion with 1 kg/s geothermal water flow rate as a heat source was evaluated to obtain the basic data for the optimal design of cycle with respect to the classification of the working fluid. The basic thermodynamic model for cycle is rankine cycle and the geothermal water and deep seawater were adapted for the heat source of evaporator and condenser, respectively. R245fa, R134a are better to use as a working fluid than others in view of the use of geothermal water. It is important to select the proper working fluid to operate the ocean thermal energy conversion. So, this paper can be used as the basic data for the design of ocean thermal energy conversion with geothermal water and deep seawater.

Determination of Ocean Tidal components by GPS Observations (GPS관측 데이터를 이용한 해양의 조석성분 결정)

  • 윤홍식;이동하
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2003.04a
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    • pp.45-54
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    • 2003
  • This paper deal with the GPS performance for determining the ocean tidal loading components(M$_2$, N$_2$, S$_2$, K$_2$) and the availability of permanent GPS stations(CHJU, KANR) established in Korea. We determined the ocean tidal loading components from GPS observation by spectrum analysis and compared to that from global ocean tidal models(GOT00.2, FES99, CRS4.0, NAO99). Through this study, we have a sense that amplitude and phase lags of ocean tidal loading components from observed GPS data was almost equal to value calculated in ocean tide models. The diurnal ocean tide loading constituents are not considered, because unmodeled troposhere effects increase the noise level near the diurnal frequency band and prevent us from obtaining significant results.

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Evaluation of Turbidity Generated by Cutter Suction and Grab Dredgers

  • Jin, Jae-Youll;Song, Won-Oh;Park, Jin-Soon;Kim, Sung-En;Oh, Young-Min;Yum, Ki-Dai;Oh, Jae-Kyung
    • Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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    • 2003.08a
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    • pp.179-184
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    • 2003
  • It is inevitable for dredging to increase the suspended sediment concentration (SSC) of the ambient waters in some degree, which has the potential to affect the coastal ecosystem in various manners. Thus, quantitative under- standing of dredging-induced sediment loss is essential fur the reliable environmental impacts assessment. (omitted)

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Estimation of the Efficiency of a Silt Screen using a Vessel-mounted ADCP

  • Jin, Jae-Youll;Park, Jin-Soon;Song, Won-Oh;Kim, Sung-En;Lee, Kwang-Soo;Yum, Ki-Dai;Oh, Jae-Kyung
    • Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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    • 2003.08a
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    • pp.353-358
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    • 2003
  • As fur quantitative evaluation of the amount of sediments released into the ambient waters by various works fur coastal development, the instrument and method of the measurement of suspended sediment concentration (SSC) are critical for estimating the efficiency of a silt screen to reduce the spreading of sediment plumes generated by coastal works. (omitted)

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A Study on Development of a Pyrolysis Characteristics for Combustible Ocean waste (가연성 해양폐기물 열분해 특성에 대한 연구)

  • 김용섭;김도영;황기연
    • Journal of Ocean Engineering and Technology
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    • v.15 no.2
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    • pp.130-134
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    • 2001
  • Recently environmental pollution at sea becomes serious, so every governmental organization makes its effort to solve this problem. Combustible ocean wastes as of ropes, fishing nets, and tires are usually highly polymerized compound materials. The problem of ocean waste treatment can be solved by using the pyrolysis method. Pyrolysis characteristics of ocean waste was examined to get the basic data for the production system of fuel from the ocean waste. Thermogravimetric experiment showed that residual mass rate decreases as the velocity of temperature-rising becomes lower. The pyrolysis of waste rope and fishing net occurs at 300~450$^{\circ}C $ and the waste tire does at 350~450$^{\circ}C $. Pyrolysis time is estimated about 15 to 20 minutes in the temperature range when lively act of pyrolysis temperature reached.

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Application of Wavelet Transform to Problems in Ocean Engineering

  • KWON SUN-HONG;LEE HEE-SUNG;PARK JUN-SOO
    • Journal of Ocean Engineering and Technology
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    • v.17 no.3 s.52
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    • pp.1-6
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    • 2003
  • This study presents the results of series of studies, which are mainly devoted to the application of wavelet transforms to various problems in ocean engineering. Both continuous and discrete wavelet transforms were used. These studies attempted to solve detection of wave directionality, detection of wave profile, and decoupling of the rolling component from free roll decay tests. The results of these analysis, using wavelet transform, demonstrated that the wavelet transform can be a useful tool in analyzing many problems in the filed of ocean engineering.

Design and Performance Analysis of a Small Circulating Water Channel for Ocean Engineering (해양공학용 소형 회류수조 설계 및 성능분석)

  • Yim, Young-Bae;Jeong, Uh-Cheul;Park, Chan-Won;Hong, Ki-Sup
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2003.05a
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    • pp.198-202
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    • 2003
  • A small circulating water channel (CWC) for experiments ocean engineering is designed and made through the co-work of a company, MESTEC, and a college, Inha Technical Research Institute. General function of the elements of CWC are explained. The velocities in the test section are measured and analysed to estimate the performance of the CWC. The result of the velocity distribution is acceptable for experiments of ocean engineering.

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An Implementation of Integrated Information and Communication Network of Oceanographic Research Vessels for Effective Ocean Investments (효율적 해양탐사를 위한 해양조사선의 종합정보 통신망 구현)

  • Park, Jong-Won;Choi, Young-Cheol;Kang, Jun-Sun;Lim, Yong-Kon;Kim, Sea-Moon
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2003.05a
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    • pp.330-335
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    • 2003
  • This paper deals with the network interface of research and observation instruments in the oceanographic research vessel with an establishment of related database for measured information. The system is implemented to integrated communication network system which allows to effective survey by using real time observation and GUI(Graphic User Interface). The system also consists of the LAN systems and serial interface to link chemical, physical, biological and environmental relations. And, other network service and vessel data service for data communication between vessel and earth station such as INMARSAT-B, WWW service, BBS, E-Mail etc., are needed for integrated communication network system.

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Simulation of Remote Sensing Reflectance and Ocean Color Algorithms for High Resolution Ocean Sensor

  • Ahn, Yu-Hwan;Shanmugam, P.;Moon, Jeong-Eon
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.103-106
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    • 2003
  • Retrieval of ocean color information from Multispectral Camera (MSC) on KOMPSAT-2 was investigated to study and characterize small-scale biophysical features in the coastal oceans. Prior to the derivation of such information from space-acquired ocean color imageries, the atmospheric effects largely from path and the air-sea interface should be removed from the total signal recorded at the top of the atmosphere (T$_{TOA}$). In this study, the 'path-extraction' is introduced and demonstrated on the TM and SeaWiFS imageries of highly turbid coastal waters of Korea. The algorithms for retrieval of ocean color information were explored from the remote reflectance (R$_{rs}$) in the visible wavebands of MSC. The determination of coefficient (R$^{2}$) for log-transformed data [ N = 500] was 0.90. Similarly, the R$^{2}$ value for log-transformed data [ N = 500] was found to be 0.93.

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Impacts of Albedo and Wind Stress Changes due to Phytoplankton on Ocean Temperature in a Coupled Global Ocean-biogeochemistry Model

  • Jung, Hyun-Chae;Moon, Byung-Kwon
    • Journal of the Korean earth science society
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    • v.40 no.4
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    • pp.392-405
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    • 2019
  • Biogeochemical processes play an important role in ocean environments and can affect the entire Earth's climate system. Using an ocean-biogeochemistry model (NEMO-TOPAZ), we investigated the effects of changes in albedo and wind stress caused by phytoplankton in the equatorial Pacific. The simulated ocean temperature showed a slight decrease when the solar reflectance of the regions where phytoplankton were present increased. Phytoplankton also decreased the El $Ni{\tilde{n}}o$-Southern Oscillation (ENSO) amplitude by decreasing the influence of trade winds due to their biological enhancement of upper-ocean turbulent viscosity. Consequently, the cold sea surface temperature bias in the equatorial Pacific and overestimation of the ENSO amplitude were slightly reduced in our model simulations. Further sensitivity tests suggested the necessity of improving the phytoplankton-related equation and optimal coefficients. Our results highlight the effects of altered albedo and wind stress due to phytoplankton on the climate system.