{"title":"Evaluation of shipboard wave estimation techniques through model-scale experiments","authors":"U. Nielsen, R. Galeazzi, Astrid H. Brodtkorb","doi":"10.1109/OCEANSAP.2016.7485701","DOIUrl":"https://doi.org/10.1109/OCEANSAP.2016.7485701","url":null,"abstract":"The paper continues a study on the wave buoy analogy that uses shipboard measurements to estimate sea states. In the present study, the wave buoy analogy is formulated directly in the time domain and relies only partly on wave-vessel response amplitude operators (RAOs), which is in contrast to all previous works that either are formulated in the frequency domain and/or depend entirely on RAOs. Specifically, the paper evaluates a novel concept for wave estimation based on combined techniques using a wave frequency estimator, not dependent on RAOs, to detect wave frequency and, respectively, nonlinear least squares fitting to estimate wave amplitude and phase. The concept has been previously tested with only numerical simulations but in this study the techniques are applied to model-scale experiments. It is shown that the techniques successfully can be used to estimate the wave parameters of a regular wave train.","PeriodicalId":382688,"journal":{"name":"OCEANS 2016 - Shanghai","volume":"65 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130312926","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jialun Dai, Ruchen Wang, Haiyong Zheng, Guangrong Ji, Xiaoyan Qiao
{"title":"ZooplanktoNet: Deep convolutional network for zooplankton classification","authors":"Jialun Dai, Ruchen Wang, Haiyong Zheng, Guangrong Ji, Xiaoyan Qiao","doi":"10.1109/OCEANSAP.2016.7485680","DOIUrl":"https://doi.org/10.1109/OCEANSAP.2016.7485680","url":null,"abstract":"Zooplankton are quite significant to the ocean ecosystem for stabilizing balance of the ecosystem and keeping the earth running normally. Considering the significance of zooplantkon, research about zooplankton has caught more and more attentions. And zooplankton recognition has shown great potential for science studies and mearsuring applications. However, manual recognition on zooplankton is labour-intensive and time-consuming, and requires professional knowledge and experiences, which can not scale to large-scale studies. Deep learning approach has achieved remarkable performance in a number of object recognition benchmarks, often achieveing the current best performance on detection or classification tasks and the method demonstrates very promising and plausible results in many applications. In this paper, we explore a deep learning architecture: ZooplanktoNet to classify zoolankton automatically and effectively. The deep network is characterized by capturing more general and representative features than previous predefined feature extraction algorithms in challenging classification. Also, we incorporate some data augmentation to aim at reducing the overfitting for lacking of zooplankton images. And we decide the zooplankton class according to the highest score in the final predictions of ZooplanktoNet. Experimental results demonstrate that ZooplanktoNet can solve the problem effectively with accuracy of 93.7% in zooplankton classification.","PeriodicalId":382688,"journal":{"name":"OCEANS 2016 - Shanghai","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130343045","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ruchen Wang, Jialun Dai, Haiyong Zheng, Guangrong Ji, Xiaoyan Qiao
{"title":"Multi features combination for automated zooplankton classification","authors":"Ruchen Wang, Jialun Dai, Haiyong Zheng, Guangrong Ji, Xiaoyan Qiao","doi":"10.1109/OCEANSAP.2016.7485675","DOIUrl":"https://doi.org/10.1109/OCEANSAP.2016.7485675","url":null,"abstract":"Zooplankton are the key components of marine food webs. The abundance of it influences the ocean ecological balance. To efficiently monitor species richness of zooplankton and protect marine environment, marine biologists and computer vision experts started to research automated zooplankton classification system with computer vision technologies. Most current research focuses on achieving high classification accuracy. In this paper, we propose a new system based on multi features combination to enhance the zooplankton classification performance. In our system, the geometric and grayscale features, Local Binary Patterns features, and Inner-distance Shape Context features are extracted as low-level features. According to the properties of machine learning algorithms, an appropriate algorithm is chosen to generate middle-level features by processing all kinds of low-level features. After that, we concatenate middle-level features and apply Support Vector Machine to get the final classifier. By combining different types of features, the system we proposed can capture richer biomorphic information than those with a few features. And the experimental results also show that our system achieves better classification performance.","PeriodicalId":382688,"journal":{"name":"OCEANS 2016 - Shanghai","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115329597","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Underwater moving source detection based on bearing estimation variance","authors":"Shao-hua Chen","doi":"10.1109/OCEANSAP.2016.7485556","DOIUrl":"https://doi.org/10.1109/OCEANSAP.2016.7485556","url":null,"abstract":"By taking advantage of the difference in spatial distribution between underwater sound source and ocean ambient noise, a detector based on bearing estimation variance is proposed. The time delay estimation method is adopted to estimate the bearing of the source, and the test statistics is deduced to evaluate the performance of the detector. The results show that its performance is far superior to the widely used broadband energy detector. Data processing results in sea trials show that the proposed detector can detect a sound source much earlier than the energy detector.","PeriodicalId":382688,"journal":{"name":"OCEANS 2016 - Shanghai","volume":"74 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114699601","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Vibration and radiation from underwater structure in shallow water","authors":"Wei Li, Y. Chai, Qifan Zhang, Renchao Ji","doi":"10.1109/OCEANSAP.2016.7485682","DOIUrl":"https://doi.org/10.1109/OCEANSAP.2016.7485682","url":null,"abstract":"Prediction of vibration and radiation from large underwater structures is one of the most important research contents in engineering. The cylindrical shell structure is most common structure in engineering, and it is the main component of submarine at the same time. Shells with structural similarity have similar properties due to the similarity principle. Free vibration of the simple cylindrical shell in shallow waters with proper structure mesh and flow field gird is firstly carried out with the usage of finite element method (FEM). The comparison between the FEM result, analytical solution and experimental results gets a satisfactory agreement, indicating the accuracy of FEM approach when used in the fluid-structure interaction problem. A stiffened cylindrical shell structure in shallow waters, taking consideration of the surface and bottom of the waters, is also studied. The natural frequency data and radiation results provide assessment of the influences of water depth, free surface and rigid boundary occurring in the fluid-structure interaction process. The acoustic response in infinite water domain is calculated in parallel. The result shows that the impact of surface, bottom and depth in water on the structure vibration response and the acoustic radiation cannot be ignored, which could provide experimental and numerical introduction in underwater vibration and radiation prediction or measurement.","PeriodicalId":382688,"journal":{"name":"OCEANS 2016 - Shanghai","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114873914","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Meshing impact on numerical simulation of marine systems performance","authors":"Lihong Wu, Yiping Li, Huichen Zhang, Xisheng Feng","doi":"10.1109/OCEANSAP.2016.7485363","DOIUrl":"https://doi.org/10.1109/OCEANSAP.2016.7485363","url":null,"abstract":"In this paper, meshing impact on numerical simulation of marine systems is investigated. Different mesh topologies, meshing spacing, meshing refining area are discussed. Different shaped bodies such as ball, AUV and complicated motion such as propeller rotating are simulated with compared meshes in the paper. And its converging time, solution accuracy, and local domain flow characters are compared in detail. The research results of mesh refining area showed that a mesh refining area near the stern is more important than that near the bow, although there are large pressure gradients at both areas. In regards to the necessary of boundary layer mesh, we find out that for a translational motion of a marine system such as surge, sway and heave, the near wall prismatic layer mesh is necessary. And the sensitivity of numerical accuracy to the spacing of the first grid point away from the wall and numbers of layers of the near wall are discussed. While for a rotational motion, such as propeller motion, numerical calculation showed that there is not necessary to construct a boundary layer mesh in the near wall.","PeriodicalId":382688,"journal":{"name":"OCEANS 2016 - Shanghai","volume":"150 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117311690","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wen Hai-bing, Zhang Kehan, Yan Zhengchao, Song Bao-wei
{"title":"Comparison of two electromagnetic couplers in an inductive power transfer system for Autonomous Underwater Vehicle docking application","authors":"Wen Hai-bing, Zhang Kehan, Yan Zhengchao, Song Bao-wei","doi":"10.1109/OCEANSAP.2016.7485443","DOIUrl":"https://doi.org/10.1109/OCEANSAP.2016.7485443","url":null,"abstract":"Inductive power transfer (IPT) technology provides a good solution to enlarge the working range of an Autonomous Underwater Vehicle(AUV), which plays an important role in ocean observatory. Electromagnetic coupler is the most crucial component of IPT system. In this paper, two novel electromagnetic couplers, PM coupler and reshaped EE coupler for AUV docking application were proposed. Firstly, the detail structure and fixed configuration was proposed. Secondly, the reluctance model and mutual-coupling circuit model were built. Finally, an underwater IPT prototype system was set up to verify and compare the power transfer characteristics of two different novel magnetic coupling actuators.","PeriodicalId":382688,"journal":{"name":"OCEANS 2016 - Shanghai","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116087271","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"On the sign of the waveguide invariant","authors":"D. Rouseff, L. Zurk","doi":"10.1109/OCEANSAP.2016.7485368","DOIUrl":"https://doi.org/10.1109/OCEANSAP.2016.7485368","url":null,"abstract":"Acoustic propagation in the ocean waveguide is characterized by mutual interference between the multiple ray paths connecting a source-receiver pair. In the Russian literature, these interference effects have been distilled mathematically into a single parameter, the so-called waveguide invariant defined as beta. The conventional wisdom is that the numerical value of beta is negative in deep water and positive in shallow water. In the present work, it is shown how the waveguide invariant can bifurcate and simultaneously have both positive and negative components. When bifurcation occurs, range-frequency mappings of acoustic intensity become fragmented. A method to separate the positive-beta components from the negative is sketched and applied to simulated data. Possible applications are discussed.","PeriodicalId":382688,"journal":{"name":"OCEANS 2016 - Shanghai","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115159739","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Fading characteristics of ship-to-land propagation channel at 5.2 GHz","authors":"Wei Wang, R. Raulefs, T. Jost","doi":"10.1109/OCEANSAP.2016.7485529","DOIUrl":"https://doi.org/10.1109/OCEANSAP.2016.7485529","url":null,"abstract":"To investigate into the broadband over water-wave propagation channel, the German Aerospace Center conducted channel sounder measurement where the transmit antenna was mounted on a ship and the receive antenna was located on land. Using this setup, measurements were performed at 5.2 GHz in C-band, with a broadband signal of 100 MHz bandwidth. To analyze the impact on practical communication systems, the measurement bandwidth is divided into 5 subbands, each 20 MHz wide. Small scale fading behavior is studied in this paper with respect to the signal at the first delay bin for each subband. The results show that the first tap experiences Rician fading. A normal distribution is proposed to characterize the Rician K-factor of the first tap. Although the K-factor shows a slight dependence on the frequency subbands, the K-factor significantly depends on the receive antenna altitude.","PeriodicalId":382688,"journal":{"name":"OCEANS 2016 - Shanghai","volume":"62 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124839613","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A modular designed dynamic positioning experiment system and its application on a ship model","authors":"Jian Wang, Jingyang Liu, H. Yi","doi":"10.1109/OCEANSAP.2016.7485681","DOIUrl":"https://doi.org/10.1109/OCEANSAP.2016.7485681","url":null,"abstract":"This paper presents a modular designed dynamic positioning (DP) experiment system. Three modules are designed for the DP experiment system, which are onboard computer module, position sensing module and onshore control computer module. The hardware system and software are introduced. A PC/104 computer is used as the main controller of the onboard computer system, and an ARM microcontroller is used to control the driver devices of the actuators of the subject. An inertial measurement unit (IMU) and two wind direction/speed sensors connected with the PC/104 computer are chosen to measure the subject's motion data and the wind data of the experiment environment. A wireless router offers Wireless Local Area Network (WLAN) for the DP experiment system. And a camera is used to get the position data of the subject. Several experiments are done using a DP ship model. The feasibility and effectiveness of the designed DP experiment system are demonstrated by the experiment results.","PeriodicalId":382688,"journal":{"name":"OCEANS 2016 - Shanghai","volume":"2673 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123655499","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}