• Title/Summary/Keyword: Sea-and-air

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New idea about realizing automatic collision avoidance on the sea

  • Yao, Jie;Wu, Zhaolin
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2001.10a
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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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Influences of Climate Factors and Water Temperature in Squid Spawning Grounds on Japanese Common Squid (Todarodes pacificus) Catches in the East (Japan) Sea

  • Lee, Chung-Il
    • Fisheries and Aquatic Sciences
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    • v.10 no.3
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    • pp.150-158
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    • 2007
  • Data on squid catches, water temperature, and climatic factors collected for the Northwest and subtropical North Pacific were analyzed to examine the influence of oceanic and climatic conditions in spawning grounds on catches of Japanese common squid, Todarodes pacificus, in the East (Japan) Sea. The main spawning ground was divided into four sub-areas: the South Sea of Korea (R1), the southern waters off Jeju, Korea (R2), the southwestern part of Kyushu, Japan (R3), and the northern part of Okinawa, Japan (R4). Interannual and decadal fluctuations in water temperatures correlated well with squid catches in the East/Japan Sea. In particular, water temperatures at a depth of 50 to 100 m in sub-areas R3 and R4 showed higher correlation coefficients (0.54 to 0.59, p<0.01) in relation to squid catches in the East/Japan Sea than for R1 and R2, which had correlation coefficients of 0.40 or less (p>0.05). Air temperature and wind velocity fluctuations in each sub-area are correlated with water temperature fluctuations and were closely connected with variations in the surface mixed layers. Water, air temperatures and wind velocities at the main spawning grounds are linked to the Southern Oscillation Index (SOI) with higher signals in the ca. 2-4-year band. Strong changes in a specific band and phase occurred around 1976/77 and 1986/87, coincident with changes in squid catches.

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

  • Han, Kyoung-Keun;Kim, Young-Chul
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.14 no.4
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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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A Relationship between Oceanic Conditions and Meteorological Factors in the Western Sea of Korea in Winter (동계 서해의 해황과 기상인자와의 관계)

  • Go Woo-Jin;Kim Sang-Woo;Kim Dong-Sun
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.12 no.1 s.24
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    • pp.23-32
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    • 2006
  • This study was conducted to find out the effects of meterological factors on oceanic conditions when cold and dry continental air mass passes through the western sea of Korea The change of ocean conditions during the winter season were more obvious in coastal area than open sea And sea surface temperature (SST) during February is lower by $3^{\circ}C$ than December but in coastal area SST dropped by $3^{\circ}C$. As for the salinity, there was not much difference between areas except southern area of Mokpo. In the coastal regions, air temperature(AT) and SST showed a positive correlation; as the air temperature goes up with the increase of SST and when the former goes down the latter decrease. SST of open sea seems to be changed by latent (Qe) and sensible heat (Qs), when the open sea lose its heat by Qe and Qs then SST goes down And when they get the heat then the SST goes up. 1here was a positive correlation between the AT of the coastal region and sea surface salinity (SSS), when the AT goes up then SSS increase and when the former goes down the latter decrease. Precipitation during the summer seasons (June$\sim$September) appeared to the more closely related with salinity of February of the following year than those of October and December.

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

  • 이화운;김유근;김해동;정우식;현명숙
    • Journal of Environmental Science International
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    • v.10 no.2
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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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Change of Regional Atmospheric Circulation Related with Recent Warming in the Antarctic Peninsula (남극반도의 최근 온난화와 관련된 지역적 대기순환의 변화)

  • Lee, Jeong-Soon;Kwon, Tae-Yong;Lee, Bang-Yong;Yoon, Ho-Il;Kim, Jeong-Woo
    • Ocean and Polar Research
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    • v.25 no.4
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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.

Surface Heat Flux and Oceanic Heat Advection in Sendai Bay

  • Yang Chan-Su;Hanawa Kimio
    • Korean Journal of Remote Sensing
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    • v.22 no.1
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    • pp.11-24
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    • 2006
  • Coastal sea surface temperature (CSST) and meteorological data from January through December 1995 are used to estimate the net surface heat flux and heat content for Sendai Bay. The average annual surface heat flux in the area north of the bay is estimated to be $+35Wm^{-2}$, whereas the southwestern area is estimated to be $+56Wm^{-2}$. Therefore, the net surface heat flux shows a net gain of heat over the whole bay. The largest heat gain occurs near Matsukawaura, where the strong Kuroshio/Oyashio interaction produces anomalously cold SST and wind is more moderate than in other regions of Sendai Bay over most of the year. The lowest heat gain occurs around Tashiro Island, where the temperature difference between air and sea surface is lower and wind is stronger. The heat budget shows that both surface forcing and horizontal advection are potentially important contributors to the seasonal evolution of CSST in the bay. From the A VHRR and SeaWiFS data, it is found that offshore conditions between the bay and Eno Island are different due to the presence of the Ojika Peninsula. It is also shown that the temporal behaviors of SSTs in the bay are closely connected with the air-sea heat flux and offshore conditions.

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

  • Lee, Dong-Young;Chang, Sun-Duck
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.12 no.2
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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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Application of a Large Ocean Observation Buoy in the Middle Area of the Yellow Sea (황해중부해역에서의 대형 해양관측부이의 운용)

  • Shim, Jae-Seol;Lee, Dong-Young;Kim, Sun-Jeong;Min, In-Ki;Jeong, Jin-Yong
    • Ocean and Polar Research
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    • v.31 no.4
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    • pp.401-414
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    • 2009
  • Yellow Sea Buoy (YSB) was moored in the center of the Yellow Sea at 35$^{\circ}$51'36"N, 124$^{\circ}$34'42"E, on 12 September 2007. YSB is a large buoy of 10 m diameter, and as such is more durable against collision by ships and less likely to be lost or removed by fishing nets compared to small ordinary buoys of 2.3 m diameter. YSB is equipped with 12 kinds of oceanic and meteorologic instruments, and transfers its realtime observation data to KORDI through ORBCOMM system every 1 hour. Data on ocean winds, air temperature, air pressure, and sea temperature appear to be accurate, while water property sensors (AAQ1183), which are sensitive to fouling, are producing errors. YSB (2007), Ieodo ocean research station (2003), and Gageocho ocean research station, which was completed in October 2009, will establish the 2 degrees interval by latitude in the Yellow Sea, and they will contribute though the 'Operational Oceanography System' as the important realtime observation network.

Improved Free-air Gravity Anomalies by Satellite Altimetry

  • Kim, Jeong-Woo;Roman, Daniel-R.
    • Korean Journal of Remote Sensing
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    • v.17 no.4
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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.