Applied Mechanics and Materials Vols. 602-605

Abstract: Distributed underwater sensor network coverage is divided into two main categories: deterministic coverage and stochastic coverage. A strategy is put forward to deploy determinate area by using a triangular-grid method. When a coverage ratio is known, the distance between nodes can be adjusted to meet the coverage ratio in the monitored area, and the least number of sensor nodes can be calculated. Also a heuristic method is proposed for stochastic area deployment strategy. It is under the premise that the initial node location randomly deployed is given, using Voronoi diagram, the not easiest monitored path is searched, and the network coverage performance is improved by configuring the new nodes in the path. Finally it is proved that network performance is more improved by the simulation experiments, when one to four nodes are configured in the easiest breach path.

Abstract: The phase of vortical beams is very different from that of non-vortical beams. The phase of non-vortical and vortical beams in fractional Fourier transform system is investigated by selecting different parameters of the anomalous vortical beam. It is found that although the intensity distribution is similar except nearby the Fourier transform plane for the non-vortical and the vortical beams, the phase distribution is very different even the beam parameters are the same except the topological charge. The different phases bring different intensity distributions especially at the Fourier transform plane, i.e the center of non-vortical beams is a very strong intensity peaks, however the center of vortical beams is a dark region.

Abstract: Aiming at the feature representation problem of infrared video, this paper presents an approach for bag of visual words model by considering the spatial and the temporal relations among the visual features. In this approach, motion mask image was generated based on motion history image, optical flow vector is mapping to visual code book. By using motion history value and motion energy value calculating the weighting coefficient, the BOVW was constructed based on angle voting. Experiments have demonstrated improved performances on motion feature representation in the infrared video.

Abstract: To meet the growing requirement of multi-source data handling, this paper carries out the application and research of data fusion technique in network planning. The fundamental theory hierarchy of data fusion working for power system planning is established, basing on it this paper analyses the fusion model in power system planning, and then designs an application case to explain the concrete fusion process. It is proved that the application of multi-source data fusion helps to make a fuller and more effective use of the massive information resource of data systems, so that the planning decision is more reasonable.

Abstract: The accuracy of broadcast ephemeris is an important index of a satellite navigation system. The theory and method of precise ephemeris assessing broadcast ephemeris are introduced. The accuracy of GPS satellite broadcast ephemeris is assessed with the precise ones provided by IGS. The orbital coordinates of GPS broadcast ephemeris from 18th to 24th October 2013 are calculated. The analysis shows that during this time the GPS satellite broadcast ephemeris is reliable, accurate and safe as the whole, meanwhile the broadcast ephemeris accuracy is about 1 meter, better than nominal accuracy of 5 meters.

Abstract: This dissertation introduces the radar rectification principle of Neural network, and derivation of the radar errors registration algorithm based on regression neural network algorithm , the result of simulation shows that the algorithm can obtain higher effect by eliminating a variety of errors and improving precision of target.

Abstract: Due to wide frequency band, the long-distance communication is prone to be jammed by traditional radios. Furthermore, severe interference will lead to serious deterioration of performance. To solve this problem, the paper proposes energy-balance interference eliminated method and mixed communication algorithm, namely interference cancellation system model. The system elects a cluster head by utilizing the residual energy of nodes and the distance between cluster heads to balance the energy consumption and maximum the life cycle of the network. A Boolean vector corresponding to a random number defined is applied to this interference cancellation system. Experimental results show that under the premise of accurate channel estimation, systems using this technology to eliminate external interference in long-distance communication system have practical significance.

Abstract: With the development of the supply chain industry, the application environment has become increasingly complex, and the security demands in RFID communication are also increasing. This paper analyzes the problems and security requirements of node authentication, message accuracy and privacy protection, etc., proposes an RFID secure communication algorithm based on random numbers describing the algorithm for nodes query generation and node processing forwards. Experimental results show that the proposed algorithm has higher accuracy.

Abstract: Optimizationmethodfor noise filtering in long-distancecommunication process is researchedto improve thesignal to noise ratioof communication.Inlong-distancecommunication, thecommunication signalsare susceptible to noiseinterference, reducingthe SNRof communication.For this reason,optimization method for noise filtering of multiplicative noise anti-interference in​​long-distancecommunication is proposed.Noisecharacteristic parameterin long-distancecommunication is extracted, and direct at the abovecharacteristic parameter,noise filtering is performed. Experimentalresults show that theimproved algorithmfor noise filtering in the process of long distancecommunicationcan greatlyimprove the communicationefficiency and accuracyto meet theactual demandfor communication.

Abstract: The statistical model is used for analyzing the characteristic of the HAP-based communication channel, the structure and algorithm of LDPC encoding and decoding in DVB-S2 are studied, the LDPC BICM system over the HAP-based communication channel are established. Numerical results show the effects of different code length and coderate under different modulation methods.