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Mao C.,Wuhan Naval University of Engineering | Liu Z.,Wuhan Naval University of Engineering | Qiu Z.-M.,Navy Academy of Armament | Lu F.-X.,Wuhan Naval University of Engineering
Dandao Xuebao/Journal of Ballistics | Year: 2012

To improve the operational effectiveness of electromagnetic pulse bomb(EMPB) with cascaded flux compression, the characteristics of fuse and warhead matching were analyzed based on the directed radiation property, and the coordination system of EMPB was built. Based on the coordination system, the numerical method for the optimal detonation time of the fuse was proposed. By numerical optimization, the effect of parameters of bomb encountering target on registration precision of active antenna was obtained. The calculation figures show that the pitching angle is the principal factor affecting the registration precision. The numerical simulation results offer theoretic basis for setting attack parameters and tactical use of EMPB.

Yang W.,Navy Academy of Armament
2014 6th International Conference on Wireless Communications and Signal Processing, WCSP 2014 | Year: 2014

In cognitive radio sensor networks, one of the fundamental tasks is cooperative spectrum sensing by multiple cognitive radio (CR) sensors to improve the spectrum detection performance. However, during each cooperative sensing process, extra energy is consumed by the selected sensors through local sensing, data reporting, and data fusion activities. Thus, cooperative sensing processes call for energy efficiency. This paper investigates two practical optimization problems related to energy efficient cooperative sensing issue. One focuses on the sensors selection in a single process, with the objective to minimize the total energy consumption meanwhile the expected sensing performances are achieved. The other is an online problem, which schedules participant sensors for each process with the aim to enable the network to perform as many as cooperative sensing processes, therefore increasing the network lifetime. Due to the NP-hardness of the proposed problems, we propose heuristic algorithms for them respectively. Extensive experiments by simulations demonstrate the effectiveness of the proposed algorithms. Using the proposed algorithms, more cooperative sensing processes can be realized and the network lifetime can be extended significantly. © 2014 IEEE.

Wang L.,Yantai University | Li G.,Yantai University | Liu J.,Navy Academy of Armament | Mao W.,Yantai University
Xi'an Dianzi Keji Daxue Xuebao/Journal of Xidian University | Year: 2013

The performance of classical two dimensional (2-D) Direction-Of-Arrival (DOA) estimation algorithms degrade substantially in the presence of coherent environment. A new DOA matrix method-DOA matrix method based on data matrix reconstruction (DMR-DOAM) is proposed for 2-D DOA estimation in the coherent source environment. The proposed algorithm reconstructs two Toeplitz equivalent covariance matrices by using cross-correlation information among receiving data from arrays. Decorrelation and 2-D DOA estimation can be realized via the eigen-decomposition of the new DOA matrix. The algorithm can retain the advantages of the traditional DOA matrix method, such as automatical parameter alignment and no need of 2-D search spectrum peak. The equivalent covariance matrices only use the middle column of classical covariance matrices, so the calculation amount is reduced, and the algorithm can be realized easily. Furthermore, the paper analyzes the estimation performance and influencing factors of the proposed algorithm. Theoretical analyses and simulation results both show that the proposed algorithm is effective.

Li B.,Tsinghua University | Li B.,Navy Academy of Armament | Mu C.,Tsinghua University | Bai T.,Navy Academy of Armament | Liu Z.,Aerospace System Engineering Shanghai
Hangkong Xuebao/Acta Aeronautica et Astronautica Sinica | Year: 2014

Different from the traditional object tracking technology, extended object tracking (EOT) doesn't ignore the target's physical extension. Instead, EOT simultaneously estimates both the centroid's kinematical state and the physical extension of the target. A random matrix based EOT approach characterizes the physical extension with a random symmetrical positive definite matrix, i.e. the ellipse/ellipsoid, and establishes a measurement model which is suitable for EOT. In order to improve the tracking performance when the target maneuvers, an ellipse/ellipsoid fitting based EOT approach is proposed based on the relationship between the ellipse/ellipsoid and the symmetrical positive definite matrix. Furthermore, a hybrid approach for EOT is presented to combine the advantages of the abovementioned two EOT approaches. Simulation results show that the hybrid approach can appropriately decide whether the target is maneuvering and choose a better approach. The physical extension estimation error of the hybrid approach is lower than the other approaches, and the estimation performance of the centroid's kinematical state is also better.

Song G.-M.,Navy Academy of Armament | Zhang S.,China Shipbuilding Industry Corporation | Zhou F.,Navy Academy of Armament
Binggong Xuebao/Acta Armamentarii | Year: 2015

Routing protocol is a network layer protocol for data transmission in underwater acoustic sensor networks (UASN), and is the foundation to achieve underwater network data transmission. UASNS rely on underwater acoustic communications. The particularity of underwater acoustic communication brings challenges to the research on the routing protocols. The application background of UASNS and the necessity of underwater routing protocols are introduced, and the design challenges of routing protocols for UASNS are discussed. The design goals of underwater routing protocols are proposed, the existing routing protocols for UASNS are studied, and the routing protocols are compared and analyzed. And the key issues of routing protocols for UASNS and the future research directions are given. © 2015, China Ordnance Society. All right reserved.

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