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Quay mooring status of a ship has been studied by using the mooring analysis software AQWA. The anti-typhoon mooring computation under the combined wind wave and current loads was analyzed with a time domain computation method. The influence of the mooring line material and mooring layout has also been studied on mooring system tensions. According to the research, the mooring layout plan that complies...
Operational ocean observing system (OOOS) can meet the needs of marine disaster prevention and reduction, safeguard socio-economic development in coastal zones, and promote marine resource exploitation. As a solid foundation for the establishment of the OOOS, operational ocean observing equipment (OOOE) is attached great significance across the world. Three kinds of OOOEs in China are introduced and...
In this paper, we propose a novel approach for SSS registration based on modified phase correlation, which is capable of handling low resolution and noise. The modified phase correlation combines threshold segmentation with phase correlation to carry out side-scan sonar (SSS) image registration. Image registration aims to transform images obtained from different views to the same coordinate. Underwater...
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...
As an economical and easy deployment wave energy converter (WEC), oscillating bodies WEC is gained more and more attention, and it has great significance of research, especially on supplying power for buoy observation and underwater sensor network. Hybrid wave energy converter, it also named combined mode wave energy converter, can capture the kinetic energy of multiple degrees of freedom of an oscillating...
Accompanied with the evolution of sea floor exploration technologies, marine samples and corresponding geochemical data increased dramatically. These distributed data interconnected together within complex and evolving relationship. Heterogeneity of format, syntax and semantic becomes obstacle to knowledge integration, transmission and sharing. In order to collect and integrate these fragmented piece...
The Gulf Stream off North Carolina (NC), USA has current velocities that approach 2 ms−1 and average volume transports of 90 Sv (1 Sv= 106 m3s−1) off of Cape Hatteras, making it the most abundant MHK (Marine Hydrokinetic Energy) resource for the state. Resource availability at a specified location depends primarily on the variability in Gulf Stream position, which is least offshore of Cape Hatteras...
Cylindrical shell transducers are widely used in underwater acoustic engineering. For example, free-flooded ring transducers are often used as transmitters in underwater acoustic communication devices. However, there are few papers about the transient sound field generated by cylindrical shell transducers in a shallow ocean. In this study, the problem of the transient sound generated by a cylindrical...
Considerable interests in recent years have been directed towards the study of various mechanical devices to draw up deep ocean water (DOW), particularly the air-lift artificial upwelling devices. However, one of the obstacles which limit their application in open ocean mariculture is the difficulty in estimating the flow rate in the upwelling pipe. Conventionally, the water flow rate in the upwelling...
Underwater object detection and segmentation has been attracting a lot of interest, and recently various systems have been designed. In this paper, we introduce a novel technique to automatically detect and segment objects from underwater images via saliency-based region merging. The method is composed of three main steps. Firstly, a salient object detection model is used to detect the position of...
Along with the development of ocean technology, the development of ocean detection, monitoring and exploitation has been made. Ocean observation network is a mature, all-weather fixed observation platform, which can achieve real-time and long term monitoring of its observation range. With the forming of mobile observation network, the underwater helicopter as an important part of mobile observation...
A hybrid underwater glider(HDUG) is developed based on a folding propeller. The blades of the propeller can fold and unfold according to the motor work or not. When it stop spinning, the blades will come to a rest position. The hydrodynamic performance will vary with the position of the blades, thus the transit efficiency of the HDUG will also vary. So there must be an optimal transit efficiency for...
The sonar system of JiaoLong human occupied vehicle(HOV) consists of nine kinds, sixteen sonars for communication, navigation, positioning, and detection. There is a ultra-short baseline(USBL) and a long baseline(LBL) for positioning. USBL is used to localize JiaoLong. Through it, the mothership can get HOV position in real-time. By Acoustic Communication System, HOV can get its own position every...
Turbulence plays a crucial role in ocean dynamics and global biogeochemical cycles through redistributing heat, salt and nutrients across isodensity surfaces. Conventionally, most of microstructure measurements were conducted with vertical freefall profilers. In order to provide both a very high resolution vertical distribution of turbulent quantities and the long term series, a novel instrument MRVP...
Conformation optimization and achieve resonation with wave are two key parts of designing pendulum wave energy converters. The object of this paper is to study hydrodynamics of a novel floating type pendulum wave energy converter and make optimization through full 3-D simulations. We will also conduct experiment in a wave tank to verify our simulations.
The last decade can be considered an embryonic period for seafloor networks with the introduction of sizeable networks off the West Coast of Canada, off the West Coast of the United States and in the Mediterranean Sea, as well as smaller networks spread throughout the world's oceans. The amount of data currently available is expected to pale in comparison to future prospects as the infrastructure...
Research on the influence of specific hydrological environment change on current velocity and water exchange has a long history in oceanography; however, the majority of previous work has been based on traditional ocean models such as POM and FVCOM. This paper presents a stable joint method that combines a support vector machine with a hydrological model to predict current velocity in different hydrological...
Marine survey is one of the most important methods for oceanic research. During the marine survey process, some collected samples will be distributed in-situ to scientists. In order to effectively manage the sample data, corresponding relations of sample type should be established between the actual distributed sample records and the prior sample applications. This matching result can provide the...
Phytoplankton are photosynthesizing microscopic organisms that inhabit the upper sunlit layer of almost all oceans and bodies of fresh water. Its abundance and taxonomic composition have impact on marine ecosystem dynamic and global environment change. Therefore, many researchers pay attention to effectively monitoring phytoplankton quantity and species composition. In order to realize this purpose,...
A formula is developed in this paper to calculate array gain when the plane-wave assumption is not applied. The formula is developped based on the assumption that the noise in the deep water is Gassian white and isotropic. The performance of a vertical linear is analyzed in the range-independent ocean, and also in a weak range-dependent ocean perturbed by random internal waves. Simulation results...
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