Unsteady drag measurementsw ere conducted in a low speed wind tunnel to investigate the drag of the circular disk which was normal to the flow. The circular disk was interfered by an upstream two-dimensional rod in the horizontal symmetry plane of the disk in the Reynolds number range from 0.44×10⁵ to 2.74×10⁵ based on the disk diameter. The results indicate that the mean drag coefficient of the circular disk does not depend on the Reynolds number which was tested in present study, no matter there is an interference rod upstream of the circular disk or not Meanwhile, the interference rod leads to decrease of the mean drag coefficient and increase of the drag fluctuation of the circular disk. The increment value of the drag fluctuation increases rapidly, when the Reynolds number is beyond 1.84×10⁵. By the frequency analysis, the dominate frequency of the disk drag without the interference rod corresponds to the antisymmetric fluctuation frequency induced by the helical vortex structure(the Strouhal number is 0.135).

Aiming at the problems in the modeling design of general purpose automatic test equipment(ATE) and in order to satisfy the requirement of the model of ATE , a integrated ATE model was presented based on signal. The ATE hardware and unit under test(UUT) are both made models. A basal signal model was established based on test foundation framework(TFF).The device driver model based on signal was proposed. The UUT model was proposed based on the thought of integrating test and diagnosis. The route model was pointed out based on the thought of sharing information between models and the thought of describing route with logic switch. This model gave direction to the resource allocation, instrument-s interchangeability, the automatic generation of test program set(TPS) and fault diagnosis. So the use of the model can quicken the design process greatly and reduce the cost greatly.

A novel multichannel reservation multiple access (MRMA) protocol was presented for efficient channel sharing in mobile ad hoc networks. It employed request-to-send (RTS) and clear-to-send (CTS) dialogue on a common channel and flexibly selected conflict-free traffic channel to accomplish the transmission of data packet based on a novel channel selection scheme. The acknowledgment (ACK) packet for the data packet transmission was replied to the sender over another common channel, which effectively eliminated the influence of exposed terminal problem, and the spatial reuse of the same channel was extended to communication pairs even within 2-hops. In addition, the influence of hidden terminal problem was greatly reduced because most of possible packet collisions on a single channel were avoided due to traffic load balance on multiple channels. Finally, performance comparison of the proposed protocol with the IEEE 802.11 RTS/CTS protocol was provided, and simulation results show that it outperforms the IEEE 802.11 RTS/CTS protocol on total channel utilization and average packet delay.

In contrast to the most existing unmanned aerial vehicle (UAV) cooperative trajectory planners that are suitable for stationary targets, a novel decentralized cooperative trajectory planning method for UAV towards moving target aground was proposed. The decentralized cooperative trajectory planning scheme was given and the time advancing mechanism by alternation of self-planning and synchronized-planning was adopted to match the constraints of information transfer interval. The heuristic information function suitable for moving target aground was constructed to enhance the UAV trajectory feasibility. The heuristic search algorithm was used to generate the trajectory segments, which make UAV reacting to target movement aground. The decentralized computing method for cooperative variable was designed to reduce the cooperative computing. The simulation results show that the method could generate the real time three-dimensional cooperative trajectory for UAV towards moving target aground via information transfer and decentralized computing, which meets the real time application requirement.