• Title/Summary/Keyword: coastal-offshore

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Wave Prediction in a Harbour using Deep Learning with Offshore Data (딥러닝을 이용한 외해 해양기상자료로부터의 항내파고 예측)

  • Lee, Geun Se;Jeong, Dong Hyeon;Moon, Yong Ho;Park, Won Kyung;Chae, Jang Won
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.33 no.6
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    • pp.367-373
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    • 2021
  • In this study, deep learning model was set up to predict the wave heights inside a harbour. Various machine learning techniques were applied to the model in consideration of the transformation characteristics of offshore waves while propagating into the harbour. Pohang New Port was selected for model application, which had a serious problem of unloading due to swell and has lots of available wave data. Wave height, wave period, and wave direction at offshore sites and wave heights inside the harbour were used for the model input and output, respectively, and then the model was trained using deep learning method. By considering the correlation between the time series wave data of offshore and inside the harbour, the data set was separated into prevailing wave directions as a pre-processing method. As a result, It was confirmed that accuracy and stability of the model prediction are considerably increased.

Analysis of Wave Characteristics near Wangdeungdo through Southwest Sea Wave Hindcasting (서남해 파랑 후측모의 실험을 통한 왕등도 인근 파랑 특성 분석)

  • Young Ju Noh;Min Young Sun
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.36 no.2
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    • pp.61-69
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    • 2024
  • Wave conditions are crucial for offshore wind farm design, particularly in determining structural loads and layout. However, there is limited wave hindcasting research for the Wangdeungdo Island area, a potential offshore wind site. This study used the MIKE21 model for a year-long wave hindcast around Wangdeungdo in 2021. Validation showed high reproducibility for significant wave heights with RMSE values of 0.177 and 0.225 and Pearson correlations of 0.971 and 0.970 at Sangwangdeungdo and Buan buoys. Subsequent analysis of the wave characteristics near Wangdeungdo indicated significant seasonal variations and differences in maximum significant wave heights across locations, which are expected to significantly impact the design loads for offshore wind structures.

2-D Experiments of On-Offshore Sediment Transport (해빈단면변형에 관한 2차원 이동상 수리실험)

  • 이종섭;박일흠
    • Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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    • 1992.08a
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    • pp.173-178
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    • 1992
  • 연안역에서 해저지형의 변화를 예측하는 것은 해빈침식제어, 하구폐색, 항로매몰문제, 방파제 및 증ㆍ양식장과 같은 연안시설물의 설치에 있어서 고려하지 않으면 안될 중요한 연구과제의 하나이다. 이러한 해저지형의 변화를 예측하기 위하여는 수평이차원의 국지역에서 순표사량의 정량적인 평가가 필요하다.(중략)

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Dynamic Analysis of Tension Leg Platform Using 3D-Curved Surface Boundary Element Method

  • Pil, Jang-Seung;Park, Jeong-Il;Kim, Jae-Gwan
    • Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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    • 1992.08a
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    • pp.140-145
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    • 1992
  • The design of large offshore structures and their operations depend critically upon the wave-induced loads and motions. Thus, over the last two decades, substantial efforts have been devoted to the development of various principles and methods which can provide these predictions in a reliable and efficient manner.(omitted)

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Target Detection Algorithm of Sidescan Sonar imagery based on GLCM(Gray Level Co-occurrence Matrix) (GLCM을 기반으로 한 사이드 스캔 소나 영상의 목표물 탐색 알고리즘)

  • 조영건;박요섭;김학일
    • Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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    • 2002.08a
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    • pp.308-315
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    • 2002
  • 해양구조물 설치(Offshore Engineering)에 대한 수요가 급증함에 따라 보다 정확한 설계와 시공을 위한 해저지형 및 지질환경에 대한 탐사(Geophysical Survey)수요가 급격히 증가하고 있다. 전자기파의 감쇄가 심한 해수로 덮여 있는 해저에 대한원격탐사 매체로는 SONAR(SOund Navigation And Ranging)시스템이 일반적으로 이용되고 있다. (중략)

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Derivation of Nonlinear Mild-Slope Equation and Numerical Simulation (비선형 완경사 방정식의 유도 및 수치모의)

  • Lee, Jung-Lyul;Park, Chan-Sung
    • Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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    • 2000.09a
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    • pp.103-112
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    • 2000
  • Early efforts to model wave transformation from offshore to inshore were based on the ray theory which accounts for wave refraction due to changes in bathymetry and the diffraction effects were ignored. Prediction of nearshore waves with the combined effects of refraction and diffraction as well as reflection has taken a new dimension with the use of the mild-slope equation and the Boussinesq equation. (omitted)

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Oil Spill Spreading of Continuous Spills

  • Lee, Jung-Lyul;Chu, Jin-Kyu
    • Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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    • 1998.09a
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    • pp.40-44
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    • 1998
  • Since oil spills discharged by offshore oil production platforms, ship accidents etc., cause many environmental problems, forecasts of drift and spreading of the spilled oil are requested as a basis for oil spill combat management. The numerical approach has been thought as the most effective methods of such forecast. In general, the oil spill model takes into account the trajectory and fate of oil, including drifting, spreading, evaporation, dispersion, emulsification, shoreline standing, and so on. (omitted)

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Legal Issues Relating to Artificial Islands, Installations and Structures in the Exclusive Economic Zone or on the Continental Shelf and Korea's Practice (국제해양법상 인공섬, 시설 및 구조물 제도의 쟁점과 우리나라의 입법태도에 관한 고찰 -배타적 경제수역 및 대륙붕을 중심으로)

  • Lee, Yong Hee
    • Ocean and Polar Research
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    • v.36 no.4
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    • pp.353-365
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    • 2014
  • Artificial islands, installations and structures have been used as a major means for ocean development and management since the early 20th century. The International legal regime to regulate the man-made offshore structures also have evolved and the UN Convention on the Law of the Sea (UNCLOS) acts as a basic international instrument for that purpose. Although the Convention includes more detailed provisions on man-made offshore structures, there are some legal issues regarding jurisdiction of coastal State on the man-made offshore structures in the Exclusive Economic Zone (EEZ) or on the Continental shelf. For this reason, this article begins by reviewing the 1958 Convention on the Continental shelf and the UNCLOS by focusing on the EEZ and the Continental shelf regime governing the man-made offshore structures. It next examines some controversial international legal issues that have emerged from the regulation of man-made offshore structures in the EEZ or on the Continental shelf. This is followed by a review of the Korean domestic laws regulating artificial islands, installations and structures in the EEZ or on the continental shelf. Finally, it closes by summarizing the findings of the above examinations, and suggests some recommendations for future works.

Distribution of Anchovy Eggs and Larvae off the Western and Southern Coasts of Korea (한국남해 및 서해 연안해역에서의 멸치난치어의 분포)

  • KIM Jin Yeong
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.16 no.4
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    • pp.401-409
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    • 1983
  • The distribution of anchovy eggs and larvae was studied using the ichthyoplankton samples and oceanographic data collected in the western and southern waters of Korea over the period of April through June in 1981 and 1982. Three water masses, the Tsushima Warm Current, the South Korean Coatal Water and the Yellow Sea Bottom Cold Water, are found to exert extensive influences of the distribution of anchovy eggs and larvae. The Tsushima Warm Current contacts with the South Korean Coastal Water to produce a coastal front between Cheju Island and Tsushima Island in the southern waters of Korea. Off the west coast of Korea, a coastal front is also formed running parallel with the western coast-line of Korea in the area between the Yellow Sea Bottom Cold Water and the extended part of the South Korean Coastal Water. In the southern waters of Korea anchovy eggs were found chiefly in the coastal waters inside the front, and larvae appeared to both sides on the front. The distribution of anchovy eggs and larvae off the west coast of Korea, however, was limited largely to the coastal waters of more than $12^{\circ}C$ in temperature. In the southern waters of Korea prelarvae appeared in the coastal area, and postlarvae in the offshore area. While in the western waters of Korea prelarvae were found in the southern part of the waters, and postlarvae in the northern part. Anchovy eggs and larvae were distributed in the considerably limited area of the coastal waters off the south coast of Korea in 1981 when the temperature gradient of the coastal front was sharper than in 1982.

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Estimation of Wave Power in Korean Coastal Waters (파랑에너지 해석 및 가용량 평가 연구)

  • 김현주;최학선;김선경
    • Journal of Ocean Engineering and Technology
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    • v.12 no.1
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    • pp.107-112
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    • 1998
  • The purpose of this study is to analyze the amount of available wave power and its characteristics related to the development of apractical system for ocean wave energy conversion in Korean coastal waters. The analysis method of wave power was established through comparison between theory and numerical simulation of deep sea wave by Inverse Fourier Transform with random phase method. Based on the results of comparison, wave power was estimated by use of data set from observed offshore and coastal waves and hindasted deep sea waves around the Korean peninsula. Annual mean wave power is estimated as about 1.8 ~ 7.0 kW for every metre of wave frontage at East sea, 1.5~5.3 kW at South sea and 1.0 ~ 4.1 kW at West sea, respectively. Mean wave power along deep sea front of coastal waters of Korea amounts to about 4.7 GW. Regional distribution and seasonal variation of wave power were discussed to develop practical utilization system of wave power of not so high grade of available wave power.

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