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Zhang W.,Wuhan Naval University of Engineering | Cheng J.,Wuhan Naval University of Engineering | Jiang W.,Science and Technology on Underwater Acoustic Antagonizing Laboratory
Wuhan Ligong Daxue Xuebao (Jiaotong Kexue Yu Gongcheng Ban)/Journal of Wuhan University of Technology (Transportation Science and Engineering) | Year: 2013

In order to solve the problems that MUSIC algorithm DOA estimation performance in the background of non-stationary noise is degradation and it detection signal number limited by array element. Spatial Time-Frequency Distribution is used to designe a single vector hydrophone WVD-MUSIC algorithm, which select the time-frequency point to construct time-frequency correlation matrix, instead of the correlation matrix in the MUSIC algorithm. New method in the noise suppression, spatial distinguishing and multi-objective distinguishing capability superior than the original method is verified by simulation. Source


Fan W.,Science and Technology on Underwater Acoustic Antagonizing Laboratory | Fan W.,Shanghai Marine Electronic Equipment Research Institute | Liu L.,Shanghai Marine Electronic Equipment Research Institute
Proceedings - 5th International Conference on Instrumentation and Measurement, Computer, Communication, and Control, IMCCC 2015 | Year: 2015

This paper briefly describe an experimental work which aims at using an acoustic parametric source to detect buried objects. A broadband (150∼250 kHz) transducer is used as a parametric source and transmitting primary frequency signals with CW and LFM envelope at various pulse lengths and bandwidths. Scattering measurements from a buried metal disk of 15cm diameter is implemented in a test tank of size 1m×0.7m×1m. The results show that the acoustic response between the watersediment interface and the buried disk can be distinguished clearly in the time domain by transmitting a broadband (5∼35 kHz) difference frequency LFM signal without envelope correction, and the reverberation signal is weak due to narrow beam of the parametric source. © 2015 IEEE. Source


Chen Q.,Xiamen University | Sun H.,Xiamen University | Qi J.,Xiamen University | Gu Y.,CAS Beijing Institute of Acoustics | Wang H.,Science and Technology on Underwater Acoustic Antagonizing Laboratory
Harbin Gongye Daxue Xuebao/Journal of Harbin Institute of Technology | Year: 2016

To improve the robustness of the communication system in complex underwater acoustic environment, the hybrid carrier system based on WFRFT was put forward. To obtain the optimal transformation order, the hybrid carrier system is designed with the lowest bit error rate as optimization goal. Simulation results show that BER performance of hybrid carrier system is between the traditional single/multi carrier systems in multipath channels. However, system performances with the optimal order are superior to single/multi carrier systems under the doubly selective fading channels. It has the excellent characteristics of the single/multi carrier systems and it is thus prospective in improving the robustness of the communication system. © 2016, Editorial Board of Journal of Harbin Institute of Technology. All right reserved. Source


Chen Y.,Science and Technology on Underwater Acoustic Antagonizing Laboratory | Wen W.,Xiangtan University
2012 International Conference on Wireless Communications, Networking and Mobile Computing, WiCOM 2012 | Year: 2012

Without mutation and crossover operators, Particle Optimization Algorithm (PSO) is more liable to converge on a local minimum than genetic algorithm. Therefore, a distributed PSO based on multi agent system is proposed to overcome this shortcoming by importing mutation operators in genetic algorithm. In the evolution process, the agent swarms with different mutation operators run independently. Client agent swarms inform their individuals with highest fitness to the host agent swarm so as to replace its worst after certain generations of evolution. Therefore, the whole particle swarm enjoys a higher probability of finding the global optimum. Numerical results show the proposed method can find better solutions than other methods. Distributive in nature, it can run concurrently on many platforms scattered over local area network and even Internet for large-scale combinatorial combination problems. © 2012 IEEE. Source


He X.,Science and Technology on Underwater Acoustic Antagonizing Laboratory | He X.,Shanghai Marine Electronic Equipment Research Institute
AIP Conference Proceedings | Year: 2012

The interior acoustic field of a dome is focused as a column below the domes when the source is located at half of the radius of the dome. This paper investigates the sound field reflected by a concave spherical surface from a source which on the axis of the spherical surface. The formula for calculating the field have been given, which the sound beam constrict to a point which locate at the centre of the concave when θmax=90°, and There would be a sound beam while the θmax<90°, but it works nearly. © 2012 American Institute of Physics. Source

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