Abstract:Considering that a fighter carrying miniature air-launched decoy（MALD） is in the process of one-to-one medium range air combat as a scenario, a coordination attacking strategy model for MALD and fighter based on receding horizon control (RHC) is established to solve the complicated problem. Dynamical models of MALD, fighter and target are built. Based on the analysis of the MALD bam function and coordinated function, the decision-making objective function is build. A method of coordination attacking strategy of MALD and fighter based on particle swarm optimization (PSO) and RHC is proposed. Simulation results show that the use of this algorithm can bam the target and improve the probability of our fighter's survival and combat effectiveness in the process of attack.

Abstract:In order to guarantee the rationality of the high-speed exit settings, the problem how to set the high-speed exit is studied systematically from the point of increasing the utilization ratio of airfield high-speed exit。 Through the analysis of the characteristics of aircraft landing running distance, the rule is found that the main factors impacting on the high-speed exit location are of normal distribution. Aimed at the high-speed exit used by single type and multi-type of airplanes concepts of utilization ratio and comprehensive utilization are constructed, and optimization models of high-speed exit location are built based on the concepts of both the utilization ratio and the comprehensive utilization. Based on the optimization models, the high-speed exits location for a typical combination of airplanes are optimized, and the steps how to determine the location of high-speed exits based on utilization ratio are summarized. The method proposed in the paper is of an important reference value to the setting of high-speed exit in military airfields.

Abstract:To solve the manned-unmanned combat agents coalition formation problem in task enforcement, a method of the coalition formation strategy of task grouping first and the agents-group matching is adopted. The concept of task distance is introduced in order to make best use of the correlation transitivity between tasks. Then the tasks grouping strategy of coincident task requirement is designed and the grouping solution-finding method based on reachable matrix transform is presented. Considering the match degree priority and agent capability utilization efficiency in combat agents and task groups, the combat agent and task group match strategy based on auction mechanism is designed. A task coalition formation project under a given scenario is achieved by calculating, the resource redundancy of the formed task coalition is analyzed, which shows that the proposed coalition formation strategy and method are effective.

Abstract:The inter-coordinate transformation relation between target body coordinate and ground-based radar coordinate is defined and derived, the azimuth and the elevation of line of the sight of radar in target body coordinate are obtained in this paper. All-airspace static RCS value can be available by establishing typical stealth aircraft models, including F-22, in software FEKO and the RCS characteristic variation of the dynamic target is simulated and analyzed by using Matlab. The simulation results show that different altitudes and route shortcuts all can influence the RCS series of maneuver target, and the RCS value is lower when the target takes some proper pitch movement. Also the simulation can provide a foundation for the design of flight track for stealth aircraft in simulating active attack.

Abstract:Exact prediction of unsteady aerodynamics is of great importance to the design and study of advanced combat aircraft. In response to the problem of complex calculating and lack of considerable factors in handling normal state-space model, a new flow separation model and a new state-space aerodynamics model are put forward in this paper. Compared with normal state-space model, complex calculation of differential equations is avoided and simultaneously a new influence factor -pitching angular velocity is introduced in the new state-space model which makes the physical meaning of the new state-space model proposed in the paper become clearer and more definite. At the same time, the static and dynamic proceedings are combined into one equation by the flow separation model proposed in the paper. At last, the large amplitude oscillation wind tunnel data are used for testing, the result suggests that the unsteady aerodynamic model proposed in this paper can describe the time-delay characteristics of the aerodynamic force and fit well with the wind tunnel test data.

Abstract:MHD acceleration technology is of great hope in application. In this paper, with a MHD experimental system based on shock tunnel being used, the supersonic nozzle and test section (segmented Faraday accelerator) are designed as well as reasonable electric field and magnetic field facilities. Experiments under different magnetic induction are carried out. Under the conditions of 1.1 MPa driver pressure, 500Pa driven pressure and 400 V capacitance voltage, some results are obtained as follows: With the increase of the magnetic field, the voltage at electrode pair #10 rises, while the current is decreased, the input power and the load factor are decreased. When magnetic inductions are differently as 0.5 T, 1 T and 1.5 T, the conductivities of supersonic airflow are about 181 S/m, 81 S/m and 50 S/m respectively, and the increasing rates of outlet speed are estimated to be 16.1%, 14.7% and 14.3% by evaluation method of using open circuit voltage at electrode pair #20. The conductivity of supersonic airflow has an important effect on acceleration, and both the enhancements in electric conductivity and in efficiency are simultaneously needed to improve MHD acceleration.

Abstract:For studying the aerodynamic characteristics of rocket in the process of the rocket separating from the plane internally carried air-launched launch vehicle, especially when the rocket is at high angle of attack, CFD is applied to the simulation of rocket aerodynamic characteristics. Based on the improvement of rocket shape, the rocket aerodynamic characteristics with Mach number and angle of attack can be obtained. The analysis of the aerodynamic characteristics of the improved rocket model shows that the rocket tail improved into a convergent nozzle is of great benefit to the attitude adjustment. These analyses provide a theoretical foundation for the further research on rocket attitude stabilization and track design.

Abstract:As the sole supporter of anti-TBM operation, the operational effectiveness of ballistic missile defense (BMD) system attracts more and more attention. The operation simulation by using the theory of System Dynamics (SD) is a feasible study method for the anti-TBM operational effectiveness of the ballistic missile defense (BMD) system. The SD model structure of the anti-TBM operational efficiency assessment is given,and the influence relations among the factors are analyzed. The SD model of the anti-TBM operation is built,the model simulation experiment is executed. And the simulation result is analyzed. The modeling example shows that SD for the anti-TBM operational study is feasible and effective.

Abstract:The paper puts forward a new thinking of anti-main-lobe jamming based on multi-static coherent radar. Firstly, the paper analyzes of the feasibility of the anti-main-lobe jamming based on multi-static coherent radar; secondly, proposes the improved two-steps adaptive algorithm. Through the comparison between the simulations of five different algorithms, the result shows that the NVFF-RLS adaptive algorithm proposed in this paper is better than other four algorithms in both the convergence speed and the effect of target signal separation which improve SINR about 30 dB to 36 dB. Simultaneously the cancellation effect states the advantages and the important military value of the anti-main-lobe jamming based on multi-static coherent radar.

Abstract:This paper analyses the PDA algorithm, which is commonly used in plot-track association. Aimed at the problem of bug tracking when it works in dense targets environment, an improved algorithm is proposed and the concept of subjection degree is introduced. After determining the subjection degrees between all the effective measurements and the corresponding targets by calculating statistical distance, intersecting trace windows are split, then PDA algorithm is applied to associating plots with tracks in independent track windows, and Kalman filter is applied to estimating real states of targets. In the simulation, the algorithm proposed in this paper is compared with JPDA algorithm, and the results show the proposed algorithm is slightly decreased in correct association rate, and substantially decreased in calculation.

Abstract:In order to get the key parameters of the Projectile Point of the sub-warheads, the external trajectory equation of bullets is constructed and the rule of the cluster warhead's fall point is analyzed based on a model of warhead with sub-warheads and the structure of excessive segments arrangement. This paper proceeds from the operational effectiveness, elects a search algorithm based on the shape and area of target. After simulation investigation, the use of this algorithm can ensure that the warheads effectively cover the whole area of the target, and the maximum error is only 2.5%. Therefore, the algorithm is efficient in improving the operational effectiveness of the shrapnel, and also can provide a new thought for the use and the development of the shrapnel.

Abstract:A novel dual-composite right/left-handed transmission line is proposed in this paper based on the reference ［8~9］, and its electromagnetic characteristics are investigated. The dispersion curve of the proposed structure has been derived by using Bloch-Floquet theory and simulator, and the D-CRLH is proved. The equivalent circuit model is given, and the extractive parameters of the model are extracted. The influences of the change of the structure parameters on its electromagnetic characteristics are analyzed by Ansoft HFSS10. Compared with the structure in reference ［8~9］, the proposed structure is simpler,and is easy to adjust in its parameters. What is more, the proposed structure is of symmetrization, and can be used in the design of microstrip antenna.

Abstract:A novel S-shaped electromagnetic band gap (EBG) ultra-wideband band-pass filter based on substrate integrated waveguide (SIW) is proposed. The filter is designed based on the band-stop characteristics of EBG and can obtain ultra-wideband by etching different dimensional S-shaped on the surface of substrate integrated waveguide .The designed band-pass filter with a center frequency as 9.03 GHz and relative fractional bandwidth 26.14% shows good band-pass characteristics with the frequency band between 7.85~10.21 GHz while the insertion loss is less than 1.54 dB and still the designed filter has the advantage of narrow band-pass, low insertion loss, compacted and good selectivity etc. that's better than the results in the referrence［8~10］.the good agreement between the measured results and the simulated results demonstrates that the design of this proposed filter is effective.

Abstract:In order to detect the increasingly serious distributed denial of service (DDoS) attack on the internet, an algorithm for detecting DDoS attack based on multi-dimensional information entropy is proposed. First of all, according to the property of DDoS attack, the multi-dimensional detecting vector which is capable of distinguishing attack from normal traffic is constructed based on conditional entropy and discrepant entropy. Then the sliding multi-dimensional non-parameter CUSUM algorithm with the capability of amplifying the discrepancy between normal and abnormal network traffic is adopted to detect DDoS attack. The experiments over actual and composite network attack traffic show that the proposed algorithm can detect all the DDoS attacks in both traces. Meantime, the proposed algorithm is capable of detecting DDoS attack quickly and it can be applied in the high backbone network.

Abstract:According to the vulnerability of the optical network from the Geography Distribution, this paper gives a method of constructing the model of geographical disaster and researching the vulnerability of optical network. The paper also proposes a spatial probabilistic model to simulate the disaster of real-world scenarios and correlated link failures and simultaneously analyzes the correlation among the disasters. According to correlated link failures of geographical disaster, the four scenarios of disaster of the two classes those are of inhibition and clustering are analyzed by choosing the variance, radial and probability density. By computing the reliability of the four scenarios of disaster, the conclusion is obtained that the most effective range is 200 km and the type of the attack is of clustering disaster. Then the most effective attack is adopted to simulate in the actual network topology, the result shows that the use of this scheme can capture the vulnerable region and reduce the time complexity of algorithm.

Abstract:The timing logic problem of gate-level information flow is investigated based on basic GLIFT theory, the implementation of four typical triggers is given when the system clock is trusted.The gate-level information flow tracking logic area, time delay and power consumption are evaluated for the test vectors of the IWLS set using Synopsys compiler to generate 90 nm standard library files. Compared with the original GLIFT code, the average area of the circuit is reduces more than 50%, time delay is reduces about 13% when timing logic is introduced. The obtained area and time delay information reflect the complexity of fine-grained control of information flow; the simulation results of power consumption comparison show that the power consumption of the tracking logic reaches about 5 to 20 times the original logic, the power consumption issues need further research and optimization.

Abstract:Based on the analysis of pulsed remote field eddy current principle,this article applied the pulsed remote field eddy current technology in the detection of nonmagnetic aviation metal plate components with using U-type component,simulated and designed hollow model,assembled magnetic model, connected magnetic circuit model,compared the distance of the three models' transition zone,the defects detection sensitivity, and the detection capability of the three models for different thickness plates.The simulation results show that, with connected magnetic circuit of the sensor model can not only narrow the distance between the excitation and detection coil from 20 mm to 10 mm,but also can improve the sensitivity of defects detection,while it has a stronger detection capability for more than 11 mm thickness plates.

Abstract:To meet the needs of wireless sensor network with MIMO technology, the cooperative MIMO system is built based on cluster and the transmission process is analyzed. To resolve the problem of error propagation caused by the transmission between the head node and the cooperative node in the same cluster, the cooperative MIMO system concatenated LDPC coding is designed and the realization process of layered decoding algorithm is analyzed in detail. The error performance under the same signal-to-noise ratio with different antenna number and the error performance of the different signal-to-noise ratio with same antenna number between the cluster head node and cooperative nodes are simulated. Besides, the performances of the cooperative MIMO system concatenated LDPC coding with two transmitters and one receiver, and with two transmitters and two receivers are simulated, which can be extended to system with multiple transmitters and multiple receivers. The simulation results show that the cascaded LDPC coding cooperative MIMO system can effectively solve the problem of error propagation in cooperative MIMO system. Meanwhile the LDPC layered decoding algorithm is used at the receiving end, compared with conventional BP decoding, in the same simulation conditions, convergence is faster and error correction performance is better.

Abstract:Researches on Transform Domain Communication System (TDCS) are almost confined to theoretical simulation and corroboration, and rarely involve hardware platform. In this paper, firstly, the fundamental and key techniques of TDCS are analyzed, the working principle of USRP2 is introduced; and then a dynamic platform of TDCS based on USRP2 is designed, the dynamic simulation module library of TDCS is compiled by Level-2 Matlab S-Function. Finally, the communication system is set up in the environment of Matlab/Simulink. Signal transmission and reception in actual wireless channel are tested through two USRP2. The results indicate that the TDCS system designed in this paper based on USRP2 can accurately realized signal transmission and reception in actual wireless channel, and has better data transmission error rate. This paper is of a certain value to the practical application of Cognitive Radio technology.

Abstract:Using conventional solid-phase sintering technique combined with a special atmosphere controlling technique, KNN-based lead-free transparent ceramics, x Ba(Sc0.5Nb0.5)O3-(1-x) (K0.5N0.5)NbO3 (xBSN-(1-x) KNN in simplified form), are prepared and investigated. The XRD, micro-structure, dielectric performance and optical transparency are investigated. The results show that such ceramics are of pseudocubic-Perovskite structure without any other impure phase. The grain size is comparable to the light wavelength and the grains are highly condensed without evident crystal borders. When x=0.05, d33 can reach up to 110 pC/N maximally. Such ceramics are of excellent transparency and the optical transparency reaches about 47 % in the visible light range,and the optical transparency is near 70 % at the near-infrared wavelength 2 500 nm. Such ceramics are a type of environment-friendly lead-free transparent ceramics which is promising in replacing lead-based transparent ceramics.

Abstract:Na1.5Bi2.5Nb3O12 powders which are high crystallinity and perfect fine-grains are prepared by hydrothermal method using Nb2O5, Bi2O3, NaOH as aw materials, and KOH serves as a mineralizer with the addition of ethylene glycol. The influence of the reaction temperature and the reaction time on the phase structure is analyzed by means of X-ray diffraction (XRD). The morphology of Na1.5Bi2.5Nb3O12 is analyzed by scanning electron microscopy (SEM). The results show that pure Na1.5Bi2.5Nb3O12 plates-layered structure powders with the average thickness of 50nm and diameter of 200 nm are synthesized at the reaction temperature of 160 ℃ and the reaction time of 18 h.