• Title/Summary/Keyword: 해무

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Sea-fog Dehazing Technique base on GPU for CCTV Monitoring and Controlling System (CCTV 관제시스템을 위한 GPU 기반 해무제거 기술)

  • Kim, eun-soo;Lee, youn-hyuk;Seo, young-ho;Choi, hyun-jun
    • Proceedings of the Korea Contents Association Conference
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    • 2017.05a
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    • pp.461-462
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    • 2017
  • 본 논문에서는 해양관제 시스템을 위한 해무(sea-fog) 제거 기술을 제안한다. 이 기술은 실시간 동작을 위해GPU(graphic processing unit)를 기반으로 운용이 된다. 구현에 사용된 GPU는 nVidia사의 GTX 680으로 두 대의 GPU를 사용하여 실시간 동작을 확인하였다.

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항로표지용 4채널 카메라 시스템을 이용한 해사 안전 서비스 알고리즘에 관한 연구

  • 박세용;황신혁;김승규;송영남;임태호
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2023.05a
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    • pp.282-283
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    • 2023
  • 항로표지 부이의 안전한 관리 및 해사 안전 서비스 제공을 위한 4채널 카메라 시스템 하드웨어를 구현하고, 항로표지 부이 근접 선박 감지, 해무 강도 측정, IMU 센서를 이용한 파고 측정 알고리즘을 구현하여 육상으로 전달하는 기능을 개발하였다

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A Study on Prediction System of Sea Fogs in the East Sea (동해의 해무 예측 시스템 연구)

  • 서장원;오희진;안중배;윤용훈
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.8 no.2
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    • pp.121-131
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    • 2003
  • We have found that the east coast of Korea has had few sea fogs on January, February, November and December for the past 20 years by the analysis of monthly fog frequency and duration time. These phenomena appear to relate to the topographical characteristics of which the Taebaek Mountains descends toward the east to bar the radiation fog. On the other hand, the cause of occurring the spring and summer fog which has 90% of the whole frequency is divided into three cases. The first is the steam fog caused by the advection of the northeast cold air current on the East Sea due to the extension of Okhotsk High. The second is the advection fog caused by cooling and saturation of warm airmass advected on cold sea surface. And the last is the frontal fog caused by the supply of enough vapor due to the movement of low-pressure system and the advection of cold air behind a cold front. While, we simulate the sea fog for the period of the case studies by implementing fog prediction system(DUT-METRI) that makes it possible to forecast the fog in the vertical section of neighborhood of the East Sea and to predict the sea surface wind, relative humidity, ceiling height, visibility etc. Finally we verified this result by satellite image.

Study on Detection Technique for Sea Fog by using CCTV Images and Convolutional Neural Network (CCTV 영상과 합성곱 신경망을 활용한 해무 탐지 기법 연구)

  • Kim, Na-Kyeong;Bak, Su-Ho;Jeong, Min-Ji;Hwang, Do-Hyun;Enkhjargal, Unuzaya;Park, Mi-So;Kim, Bo-Ram;Yoon, Hong-Joo
    • The Journal of the Korea institute of electronic communication sciences
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    • v.15 no.6
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    • pp.1081-1088
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    • 2020
  • In this paper, the method of detecting sea fog through CCTV image is proposed based on convolutional neural networks. The study data randomly extracted 1,0004 images, sea-fog and not sea-fog, from a total of 11 ports or beaches (Busan Port, Busan New Port, Pyeongtaek Port, Incheon Port, Gunsan Port, Daesan Port, Mokpo Port, Yeosu Gwangyang Port, Ulsan Port, Pohang Port, and Haeundae Beach) based on 1km of visibility. 80% of the total 1,0004 datasets were extracted and used for learning the convolutional neural network model. The model has 16 convolutional layers and 3 fully connected layers, and a convolutional neural network that performs Softmax classification in the last fully connected layer is used. Model accuracy evaluation was performed using the remaining 20%, and the accuracy evaluation result showed a classification accuracy of about 96%.

Study on sea fog detection near Korea peninsula by using GMS-5 Satellite Data (GMS-5 위성자료를 이용한 한반도 주변 해무탐지 연구)

  • 윤홍주
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.4 no.4
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    • pp.875-884
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    • 2000
  • Sea fog/stratus is very difficult to detect because of the characteristics of air-sea interaction and locality ,and the scantiness of the observed data from the oceans such as ships or ocean buoys. The aim of our study develops new algorism for sea fog detection by using Geostational Meteorological Satellite-5(GMS-5) and suggests the technics of its continuous detection. In this study, atmospheric synoptic patterns on sea fog day of May, 1999 are classified; cold air advection type(OOUTC, May 10, 1999) and warm air advection type(OOUTC, May 12, 1999), respectively, and we collected two case days in order to analyze variations of water vapor at Osan observation station during May 9-10, 1999.So as to detect daytime sea fog/stratus(OOUTC, May 10, 1999), composite image, visible accumulated histogram method and surface albedo method are used. The characteristic value during day showed A(min) .20% and DA < 10% when visible accumulated histogram method was applied. And the sea fog region which is detected is similar in composite image analysis and surface albedo method. Inland observation which visibility and relative humidity is beneath 1Km and 80%, respectively, at OOUTC, May 10,1999; Poryoung for visble accumulated histogram method and Poryoung, Mokp'o and Kangnung for surface albedo method. In case of nighttime sea fog(18UTC, May 10, 1999), IR accumulated histogram method and Maximum brightness temperature method are used, respectively. Maxium brightness temperature method dectected sea fog better than IR accumulated histogram method with the charateristic value that is T_max < T_max_trs, and then T_max is beneath 700hPa temperature of GDAPS(Global Data Assimilation and Prediction System). Sea fog region which is detected by Maxium brighness temperature method was similar to the result of National Oceanic and Atmosheric Administratio/Advanced Very High Resolution Radiometer (NOAA/AVHRR) DCD(Dual Channel Difference), but usually visibility and relative humidity are not agreed well in inland.

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Operation Measures of Sea Fog Observation Network for Inshore Route Marine Traffic Safety (연안항로 해상교통안전을 위한 해무관측망 운영방안에 관한 연구)

  • Joo-Young Lee;Kuk-Jin Kim;Yeong-Tae Son
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.29 no.2
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    • pp.188-196
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    • 2023
  • Among marine accidents caused by bad weather, visibility restrictions caused by sea fog occurrence cause accidents such as ship strand and ship bottom damage, and at the same time involve casualties caused by accidents, which continue to occur every year. In addition, low visibility at sea is emerging as a social problem such as causing considerable inconvenience to islanders in using transportation as passenger ships are collectively delayed and controlled even if there are local differences between regions. Moreover, such measures are becoming more problematic as they cannot objectively quantify them due to regional deviations or different criteria for judging observations from person to person. Currently, the VTS of each port controls the operation of the ship if the visibility distance is less than 1km, and in this case, there is a limit to the evaluation of objective data collection to the extent that the visibility of sea fog depends on the visibility meter or visual observation. The government is building a marine weather signal sign and sea fog observation networks for sea fog detection and prediction as part of solving these obstacles to marine traffic safety, but the system for observing locally occurring sea fog is in a very insufficient practical situation. Accordingly, this paper examines domestic and foreign policy trends to solve social problems caused by low visibility at sea and provides basic data on the need for government support to ensure maritime traffic safety due to sea fog by factually investigating and analyzing social problems. Also, this aims to establish a more stable maritime traffic operation system by blocking marine safety risks that may ultimately arise from sea fog in advance.