Browsing NTNU Open by Author "Dong, Hefeng"

Now showing items 41-49 of 49

    • Study on backscattering from fish school near pump intake 

      Liu, Ling Fei (Master thesis, 2013)
      In this master project, acoustic method was applied for estimating the gradually changed fish density during the crowding near the pump intake in salmon plant. The purpose was to detect if the sensitivity of the echo sounder ...

    • Subsurface resistivity estimation by seismic-guided inversion of marine controlled-source electromagnetic data 

      Guo, Zhenwei (Doctoral theses at NTNU;2016:289, Doctoral thesis, 2016)
      Marine controlled-source electromagnetic (CSEM) has been in commercial use for offshore hydrocarbon exploration for fifteen years. It is significant for geologists and geophysicists to design and interpret a marine EM ...

    • Survey on Communication and Networks for Autonomous Marine Systems 

      Zolich, Artur Piotr; Palma, David; Kansanen, Kimmo; Fjørtoft, Kay Endre; Sousa, João; Johansson, Karl H.; Jiang, Yuming; Dong, Hefeng; Johansen, Tor Arne (Journal article; Peer reviewed, 2018)
      The rapid development of autonomous systems and Information and Communications Technologies (ICT) create new opportunities for maritime activities. Existing autonomous systems are becoming more powerful and utilise the ...

    • Time Diversity Passive Time Reversal for Underwater Acoustic Communications 

      Siddiqui, Salman Ijaz; Dong, Hefeng (Journal article; Peer reviewed, 2019)
      Underwater acoustic signal propagation is greatly affected by source-receiver motion, surface variations, and water column variabilities, which make the underwater acoustic communications very challenging. A passive time ...

    • Time-Frequency Fused Underwater Acoustic Source Localization Based on Contrastive Predictive Coding 

      Zhu, Xiaoyu; Dong, Hefeng; Salvo Rossi, Pierluigi; Landrø, Martin (Peer reviewed; Journal article, 2022)
      We propose a time-frequency fused underwater acoustic source localization method based on self-supervised learning with contrastive predictive coding. Firstly, two feature extractors are trained to solve the pretext task ...

    • Touch Localization by Estimating the Direction of Arrivals of Plate Edge Reflections 

      Strømsnes, Niklas (Master thesis, 2023)
      Dette prosjektet utforsker muligheten for berøringslokalisering ved bruk av metoder for estimering av ankomstvinkler (direction-of-arrival (DOA)) på Lamb-bølger som reflekteres fra kantene på en plate. Det foreslås en ...

    • Ultrasonic focusing through a steel layer for acoustic imaging 

      Talberg, Andreas Sørbrøden; Dong, Hefeng; Johansen, Tonni Franke; Måsøy, Svein-Erik; Brekke, Svein; Rommetveit, Tarjei (Journal article; Peer reviewed, 2018)
      Ultrasonic tools are being used for imaging in a large variety of fields, spanning from medical applications in a hospital to applications deep down in oil and gas wells. When applying ultrasonic imaging techniques to image ...

    • Understanding ocean acoustics by eigenray analysis 

      Hovem, Jens Martin; Dong, Hefeng (Journal article; Peer reviewed, 2019)
      Acoustics is important for all underwater systems for object detection, classification, surveillance systems, and communication. However, underwater acoustics is often difficult to understand, and even the most carefully ...

    • Underwater Source Localization and Geoacoustic Inversion based on Machine Learning 

      Zhu, Xiaoyu (Doctoral theses at NTNU;2023:246, Doctoral thesis, 2023)
      Marine environmental information is vital for marine engineering applications. Underwater acoustic remote sensing is a common approach to obtaining marine environmental information by acoustic waves. With the development ...