• 제목/요약/키워드: Sea&Air

검색결과 1,158건 처리시간 0.029초

New idea about realizing automatic collision avoidance on the sea

  • Yao, Jie;Wu, Zhaolin
    • 한국항해항만학회:학술대회논문집
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    • 한국항해항만학회 2001년도 Proceeding of KIN-CIN Joint Symposium 2001 on Satellite Navigation/AIS, lntelligence , Computer Based Marine Simulation System and VDR
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    • pp.65-74
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    • 2001
  • The rapid development of computer technology and widely application of artificial intelligent provide technology support for realizing navigation automation on the sea. which has achieved great success in shipping advanced countries like japan, England, America, Germany and also in the developing country, China. However, it still remains in the studying Period up to now in aspects of collision avoidance decision-making mathematical model and reasoning mechanism. In this paper, approaches are proposed to establish the collision avoidance automation system. One of them is based on the former studies to realize automation system by make use of finite state machine theory and following the International regulations for Preventing Collision at Sea, 1972. The others are to establish the new idea about automatic collision avoidance system by taking advantage of the free flight idea, hybrid system, game theory used in air traffic management studies in recent years and the common characteristics in both air and sea traffic management.

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ESTIMATES OF NET AIR-SEA FLUXES FOR THE TROPICAL AND SUBTROPICAL ATLANTIC BASED ON SATELLITE DATA

  • Katsaros, Kristina B.;Pinker, Rachel T.;Bentamy, Abderrahim;Carton, James A.;Drennan, William M.;Mestas-Nunez, Alberto M.
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume II
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    • pp.997-1000
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    • 2006
  • We estimate the net heat flux in the tropical and subtropical Atlantic Ocean using satellite data. These fluxes are related to changes in sea surface temperature (SST). This variable influences atmospheric circulations and is indicative of surface and subsurface oceanic circulations. We employ data from the geostationary METEOSAT-7 and 8 satellites and from the Special Sensor Microwave/Imager (SSM/I) for the shortwave and long-wave radiative fluxes, and for estimates of SST. For turbulent flux calculations, we use the bulk aerodynamic method with satellite estimates for wind speed and atmospheric humidity and temperature.

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Vertical Temperature Profile in the Yellow Sea according to the Variations of Air Temperature

  • CHO Kyu-Dae;CHO Kwang-Woo
    • 한국수산과학회지
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    • 제21권1호
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    • pp.1-10
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    • 1988
  • The vertical temperature profiles of the Yellow Sea in summer are investigated by means of the nine air temperature (AT) patterns which are classified with the AT of winter and summer. The sea surface temperature (SST) is high when the AT of summer is high, and vice versa. The gradient of thermocline in the offshore region is higher than that in the coastal region and is not always favorable with the AT patterns. The relation between sea bottom temperature (SBT) and the AT of winter is favorable when the SBT is averaged in the coastal and offshore stations. In addition, the SST of coastal stations is higher than that of offshore stations because of the strong mixing by the tidal current in the coastal region. The correlation between the AT and the SST of August is favorable (r=0.44-0.69), while the correlation between the AT of February and the SBT of August is not favorable except the stations, A2 (r=0.57) and B2 (r=0.61).

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한국서해의 해양과 대기간 에너지의 효과 (Sea-air Energy Exchange in the Eastern Yellow Sea)

  • 이동영;장선덕
    • 수산해양기술연구
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    • 제12권2호
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    • pp.37-42
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    • 1976
  • Each term of heat badget equation in the eastern Yellow Sea was calculated and the variation in relation to meteorological condition was shown for the period from September 1973 to February 1974, At Mal-do near Gunsan the maximum heat exchange occurred at the last ten days of December (--522 1y/day), while at Sunmi-do near Incheon it occurred at the middle ten days of November (--665 1y /day), The contribution of the sensible heat to total heat exchange increased rapidly, while the effect of cloudiness decreased to be negligible in winter. The values of the heat exchange fluctuated considerably with the periodic occurrence of the cold Siberiaa air mass. The mean evaporation heat estimated indirectly from the aerological data was 32 ly/day at the northern part and 269 ly/dlY at the southern part of the Yellow Sea in December 1973.

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라그랑지안 입자확산모델을 이용한 광양만 권역에서의 공기괴 재순환현상 수치모의 (Numerical Simulation for Recirculation of Air Mass in the Coastal Region Using Lagrangian Particle Dispersion Model)

  • 이화운;이현미;이순환;최현정
    • 한국환경과학회지
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    • 제19권2호
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    • pp.157-170
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    • 2010
  • Air mass recirculation is a common characteristic in the coastal area as a result of the land-sea breeze circulation. This study simulates the recirculation of air mass over the Gwangyang Bay using WRF-FLEXPART and offers a basic information about the effective domain size that can reflect recirculation. For this purpose, WRF is set up four nested domains and three cases are selected. Subsequently FLEXPART is operated on the basis of WRF output. During the clear summer days with weak wind speed, particles that emitted from Yeosu national industrial complex and Gwangyang iron works flow into emission sources because of the land-sea breeze. When land-sea breeze is strengthen, the recirculation phenomena appears clearly. However particles aren't recirculated under weak synoptic condition. Also plume trajectory is analyzed and as a consequence, the smallest domain area have to be multiplied by 1.3 to understand recirculated dispersion pattern of particles.

봄철 서해안 해무의 수치예보 (Numerical forecasting of sea fog at West sea in spring)

  • 한경근;김영철
    • 한국항공운항학회지
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    • 제14권4호
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    • pp.94-100
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    • 2006
  • The purpose of this case study is to determine the possibility of Numerical Forecasting of sea fog at West Sea in spring time. For practical method of analyzing the data collected from 24th to 26th March 2003, Numerical Weather Prediction model MM5(Mesoscale Model Version 5) and synoptic field study using synoptic chart, upper level chart, and sea surface temperature were employed. The results of synoptic field analysis summarized that sea fog at West sea in spring is intensified by the inflow of the warm flow from west or southwest, low sea surface temperature to increase the temperature difference between air and sea surface, and inversion layer to disturb the disperse. It appears that the possibility of sea fog forecasting by MM5, in view of the result that the MM5 output is similar to the synoptic fields analysis.

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대기오염물질의 장거리 수송과 열적저기압의 관계 (Relationship between Thermal Low and Long-Range Transport of Air Pollutants)

  • 이화운;김유근;김해동;정우식;현명숙
    • 한국환경과학회지
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    • 제10권2호
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    • pp.143-151
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    • 2001
  • The atmospheric conditions and the transport mechanism of long-range transport of air pollutants from coastal area to inland area were investigated using regular meteorological data and air pollution data obtatined from the southeastern area of Korea. Daytime temperature over the inland area(Taegu) was higher than that over the coastal area(Pusan) and the temperature difference of about 5~6$^{\circ}C$ when the thermal low most fully developed and the sea level pressure over Taegu was lower than that over Pusan by about 4~5hPa at that time. Therefore this low pressure appeared to the thermally induced low. Air mass polluted from the coastal area during the morning period was transported inland area, at first by the sea breeze and by the large scale wind system toward the thermal low generated in the mountainous inland region. This was explained by the fact that the concentration of air pollutants over Taegu increased throughtout the late afternoon.

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미세 격자 대기 확산 모델링을 통한 안산지역 PM10 고농도 사례 분석 (An Analysis of the Case related with High PM10 Concentrations Using a Fine Grid Air Dispersion Modeling in Ansan Area)

  • 송동웅;송창근
    • 한국환경과학회지
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    • 제12권9호
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    • pp.977-986
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    • 2003
  • In this study, the scenario for a numerical modeling of the fine grid scale air dispersion phenomena was proposed and an analysis of the special event which was occurred on September 3, 2002 was performed using by a coarse grid prognostic meteorological model, a fine grid diagnostic meteorological model and a fine grid air dispersion model. Based on the results, we found that the local circulations, like as land-sea breeze, should be seriously considered for evaluating the high PM10 concentration event and for making the reduction policy of the major air pollutant emissions in Ansan area.

Improved Free-air Gravity Anomalies by Satellite Altimetry

  • Kim, Jeong-Woo;Roman, Daniel-R.
    • 대한원격탐사학회지
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    • 제17권4호
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    • pp.297-305
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    • 2001
  • Ocean satellite altimetry-implied free-air gravity anomalies have had the shortest wavelengths removed during the processing to generate the optimal solution between multiple radar altimeter missions. ERS-1 168day mission altimetry was residualized to a reference geoid surface generated by integrating Anderson & Knudsen’s free-air gravity anomalies for the Barents Sea. The altimetry tracks were reduced and filtered to extract the shortest wavelengths (between 4 and 111 km) from both ascending and descending tracks, respectively. These data were recombined using existing quadrant-swapping techniques in the wavenumber domain to generate a correlated, high frequency gravity field related to the local geologic sources. This added-value surface adjusted the reference free-air gravity anomalies to better reflect features in the gravity field at a wavelength related to the distance between altimetry ground tracks.

남극반도의 최근 온난화와 관련된 지역적 대기순환의 변화 (Change of Regional Atmospheric Circulation Related with Recent Warming in the Antarctic Peninsula)

  • 이정순;권태영;이방용;윤호일;김정우
    • Ocean and Polar Research
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    • 제25권4호
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    • pp.503-518
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    • 2003
  • This study examines the relationship among temperature, wind, and sea level pressure to understand recent warming in the vicinity of the Antarctic Peninsula. To do this, the surface air temperature, NCEP/NCAR reanalysis wind data and sea level pressure data for the period of 40 years are analyzed. The 40-year surface air temperature data in the Antarctic Peninsula reveals relatively the larger warming trends for autumn and winter than other seasons. The variability of the surface air temperature in this region is compared with that of the regional atmospheric circulation. The surface air temperature is positively correlated with frequency of northwesterlies and negatively correlated with frequency of southeasterlies. This relation is more evident in the northern tip of the Antarctic Peninsula for autumn and winter. The trend analysis of wind frequency in the study area shows increasing and decreasing trends in the frequency of northwesterlies and southeasterlies, respectively, in the northwestern part of the Weddell Sea for autumn and winter. And also it is found that these winds are closely related with decreasing of sea level pressure in the southeastern region of the Antarctic Peninsula. Furthermore from the seasonal variation of sea level pressure in this area, it may be presumed that decreasing of sea level pressure in the southeastern region of the Antarctic Peninsula is related with warming in the vicinity of the Antarctic Peninsula for autumn and winter. Therefore it can be explained that recent warming in the vicinity of the Antarctic Peninsula is caused by positive feedback mechanism, that is, the process that warming in the vicinity of the Antarctic Peninsula can lead to the decrease of sea level pressure in the southeastern region of the Antarctic Peninsula and these pressure decrease in turn lead to the variation of wind direction in northwestern part of Weddell Sea, again the variation of wind direction enhances the warming in the Antarctic Peninsula.