Sea ice is a significant factor in ship navigation, and accurately identifying its thickness is crucial for timely decision-making to ensure ship structural integrity and personnel safety. However, current methods for...
Sea ice is a significant factor in ship navigation, and accurately identifying its thickness is crucial for timely decision-making to ensure ship structural integrity and personnel safety. However, current methods for sea ice thickness measurement, such as shipborne imaging devices and synthetic aperture radar altimeters, have limitations such as high costs, difficulties in data acquisition, and poor timeliness. In this article, we present an approach to detect sea ice thickness using a combination of sensors and machine learning techniques. Vibration signals from ship-ice collisions are collected using acceleration vibration sensors, undergo data preprocessing and time-domain alignment, and the true value of sea ice thickness is obtained through field measurements and a sea ice image information identification system. Time-frequency domain features are extracted, and feature quantity optimization is performed, followed by machine learning regression algorithms to predict sea ice thickness. Experimental results show that excellent regression results can be obtained using a single node for thickness prediction, with an R2 value of 0.908 and an RMSE of 1.374 cm. Our findings demonstrate that analyzing vibration signals generated by ship-ice collisions during vessel navigation can effectively identify sea ice thickness. this approach provides a practical and cost-effective alternative for sea ice thickness measurement and identification in the field.
In the distributed memory multicomputer,we use FSIN and TRGE to simulate the *** using the congestion control of LBR and IPR,the passing packet is authorized to the priority,which reduces the network *** the simulator...
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In the distributed memory multicomputer,we use FSIN and TRGE to simulate the *** using the congestion control of LBR and IPR,the passing packet is authorized to the priority,which reduces the network *** the simulators have different simulate *** order to coordinate the computing model and IN model,we use the synchronization to coordinate the models work *** the synchronization mechanisms are limited by the slice,which caused the message passing *** the emphasis of simulator is to find out the duration of slice,which makes the simulation speed and accuracy have a reasonable value.
the thyristor control unit (TCU) is the core component of the electric-controlled converter valve control and protection system. It is of great significance to explore the monitoring signal rules of the TCU in depth f...
the thyristor control unit (TCU) is the core component of the electric-controlled converter valve control and protection system. It is of great significance to explore the monitoring signal rules of the TCU in depth for real-time monitoring and evaluation of the operation status of the converter valve. Based on the analysis of the working principle of the TCU for the thyristor level of the converter valve and the timing characteristics of the monitoring feedback signal, this article combines the I-V curve characteristics of the thyristor in the converter valve measured on-site. Using MATLAB/Simulink, a six-pulse converter valve simulation model considering multistage thyristor series connection is established. In view of the typical statistical distribution of degradation of series devices, the influence of degradation parameters such as damping capacitors and equivalent insulation resistances of thyristor on the voltage waveform and monitoring signal timing distribution characteristics of each thyristor level in the TCU is studied, and a simulation test verification platform was built.. the results show that when the circuit parameters of the thyristor deteriorate, its feedback signal will appear ahead of the healthy thyristor, and the timing difference will increase withthe degree of deterioration. In addition, compared withthe deterioration of the damping capacitance parameter, the timing of the feedback signal is more sensitive to the insulation deterioration of the thyristor. When the insulation of the thyristor deteriorates, the healthy thyristors will bear a higher voltage compared to the deteriorated thyristor, and the voltage borne by the thyristor with a deteriorated damping capacitance will increase. Finally, the relevant conclusions obtained from the simulation were verified through experiments. this research can provide support for further real-time online evaluation of the health status of key components of the valve based on TCU unit monitoring sign
To achieve the carbon peak and neutrality target in China, the future electricity system will face the challenge of a high level of intermittent renewable energy, in which the energy storage will become the bottleneck...
To achieve the carbon peak and neutrality target in China, the future electricity system will face the challenge of a high level of intermittent renewable energy, in which the energy storage will become the bottleneck. Vehicle-to-grid (V2G) is one of the most promising technologies to provide large-scale short-term energy storage with low cost. However, there is ‘trade-off’ between the global optimality and computational burden to schedule massive distributed vehicles. Additionally, the concern on battery degradation has become a critical obstacle for electric vehicle (EV) owners to participate in the vehicle-grid integration services, which is often ignored in existing scheduling methods. therefore, a hierarchical framework is proposed in this work, using global optimization to allocate the energy consumption and supply boundaries at the upper level, and ‘self-organization’ by peer-to-peer energy trading among prosumers with blockchain to execute instant transactions at the regional lower level. the evolutionary game and double auction are applied for iteration. the characteristics of EV charging and travel are generated with real-world statistics, and the battery degradation is included in the social welfare function. the simulation example has verified the effectiveness of the proposed method, achieving 13.8% and 15.7% increase of the overall utility compared withthe method without blockchain and disregarding battery degradation, respectively.
In order to solve the contradiction between wireless communication service demand and spectrum resource shortage and enhance the utilization rate of spectrum, Cognitive Radio technology is necessary. Firstly, this pap...
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In order to solve the contradiction between wireless communication service demand and spectrum resource shortage and enhance the utilization rate of spectrum, Cognitive Radio technology is necessary. Firstly, this paper presents a cognitive engine framework structure, and then the concept of bio-inspired and its application in CR computing were emphatically introduced. Finally, in order to solve spectrum parameters problem, this paper proposed based on autonomously search algorithm. Based on population evolution,ASA algorithm employs the foraging, reproduction, selection and mutation operators, and was tested under the multicarrier simulation environment. the experiment results show that ASA algorithm can better adjust each subcarrier communication parameters according to the requirement of cognitive engine parameters optimization, which include transmitted power,modulation mode, and bit-error-rate and so on, and finally satisfy the channel condition and the dynamic changes of the user service.
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