Abstract:The detection effectiveness of the airborne early warning radar refers to the degree to which the early warning radar accomplishes its mission of early warning and detection. The radar's detection effectiveness tends to be affected by its detection range as well as its detection probability. A method of evaluating airborne early warning radar's detection effectiveness is given based on probability analysis method. A mathematic model is first established between the radar detection probability and its maximum detection range. Then, the curve of detection probability with detection range is normalized and the probability density function of detection probability is calculated. After that, the probability distribution function is acquired through integrating the probability density function of detection probability, the function has actual physical meaning and it reflects the detection effectiveness of the early warning radar. Thus, the detection range is quantitatively converted into detection effectiveness, and the curve is drawn for the detection effectiveness that varies with the change in range. And finally, by taking E2C and E3B early warning radars for example, an analysis is done aimed at the targets of Swerling I and Swerling II through comparison to verify the validity of the proposed method.

Abstract:To investigate the creep properties of loess in highfill foundation under conditions of high stress and different depth, the CU triaxial creep tests of loess at Yan'an airport are carried out under conditions of different confining pressure. The creep curves of multistep constant load and the equaltime stressstrain curves are obtained by using "Chen method". The results indicate that the creep properties of the loess are obviously influenced by stress level. The stressstrain presents linear properties under conditions of lower stress, and shows nonlinear creep properties under conditions of higher stress. Taking the confining pressure 600 kPa for example, an empirical creep model is proposed in which the stressstrain is described by exponential function and the straintime is described by hyperbolic function. The result shows that the model proposed and the empirical data are high in fitting degree, simple in formality, few in parameters and easy in achievement, can further reflect and predict the creep properties of the loess at Yan'an airport engineering compared with SinghMitchell and Mesri models.

Abstract:A finite time convergent control algorithm on integrated missile guidance and control is proposed to meet the needs of intercepting maneuvering targets at high speed. Firstly, a finitetime convergent lineofsight rate model is derived based on total integrated missile guidance and control according to the traditional total integrated missile guidance and control model. Secondly, a nonlinear sliding mode switching function with compensating factor is construct, and a finite time convergent control algorithm of integrated missile guidance and control is designed based on finitetime convergent theory. Besides, an adaptive method is adopted to estimate the maximum value of the system's uncertainty, and the higherorder sliding mode differentiators are adopted to solve the higherorder derivatives of lineofsight rate and the distance between the missile and the target. Finally, the simulation results show that the proposed finite time convergent control algorithm can achieve the finite time convergence of the lineofsight rate, and has less miss distance and shorter intercepting time, compared to the general control algorithms.

Abstract:Aimed at the problems that evaluation of pavement damage area in current standards is not clear enough, a current asphalt pavement condition evaluation model is introduced. If the repair area width reaches the pavement width, this should not be involved in pavement damage condition evaluation. Conversion coefficient K of repairing damage area should be 0.7. A Matlab testing method based on Mandonte Carlo algorithm is put forward to examine the rationality of K being 0.7. The concrete conditions are as follows: First, input the known data to Matlab to fit, and then, derive the functions of elements obey affected pavement condition index, such as repair area, total crack length and other damage areas, etc., Last, calculate the corresponding PCI to get the result of pavement condition evaluation by using Monte Carlo algorithm. Through the comparison with the actual pavement conditions and the actual test, the rationality of K being 0.7 is verified.

Abstract:Aimed at the problem that the communication blackout usually happens when a hypersonic vehicle voyage closes to the space, a model of plasma sheath is established according to the data provided by radio attenuation measurement C (RAM C) voyage experiment. Through numerical calculation, the principle of interaction between plasma and terahertz wave is analyzed, and the properties of terahertz wave propagation in plasma sheath are obtained by changing the parameters of plasma including plasma thickness, plasma density, plasma collision frequency and terahertz wave incident angle. The simulation shows that taking the terahertz frequency band as communication frequency band in near space, this is advantageous to the solution of communication blackout problem in the value of attenuation less than 30 dB at the atmospheric window of 0.22 THz. The result can be used as reference for design of communication platform in the near space.

Abstract:Microwave landing navigation system is used for UAV reducing the number of phased array scanning antenna to improve its maneuverability, by so doing, this makes scanning beam wide and main-beam's symmetry worse. The phenomenon can reduce the scanning beam pointing accuracy and robustness of original phasing methods, and consequently weaken the navigation ability. Aimed at the problem, a new method of the combined circlephase method with the improved genetic algorithm is proposed to improve the scanning beam pointing accuracy. At every scanning pointing, whenever a circlephase constant is added, the genetic algorithm is improved to optimize, determine the final phase shifters' input values and quantization manners, and overcome the shortage of circlephase method and basic genetic algorithm in using alone. The simulation shows that the beam pointing accuracy produced by the combination method is superior to the beam pointing accuracy produced by random phasing methods and basic genetic algorithm.

Abstract:A study of the fault prediction problem of permanent magnet faulttolerant motor equipped in the aircraft actuation system is advantageous to monitoring aircraft health status accurately, and providing decision support for aircraft maintenance. For a permanent magnet faulttolerant motor system in case of a hit from the outside, the traditional grey model is not high prediction accuracy. A new improved forecast method based on grey theory is proposed in the paper. The permanent magnet faulttolerant motor is a complex system belonging to high order, nonlinear and strong coupling. The paper adopts a strengthening buffer operator to deal with data sequence, restore data, eliminate the interference of shock, and forecast the failure energy data sequence through the establishment of the basic model. The results show that the original sequence is processed by strengthening buffer operator, the prediction accuracy is increased to  96.3% above, the relative prediction error is reduced by 43.06% on average compared to the primitive sequence basic model, and the fault prediction of the behavior is improved effectively.

Abstract:To evaluate the performance of 1394b bus being unmatchable at node transmission rate, the reliability of the typical stacktree topology is studied and analyzed, and an asynchronous communication model of 1394b bus is put forward in OPNET environment. First, hierarchical model of the node of 1394b is designed，and then, bus initialization, treeidentification and selfidentification are performed to complete the bus configuration by the processing module of application layer. Media access control layer is responsible for asynchronous arbitration and the process of inflow/outflow message. Finally, the utilization rate of the 1394b bus, the number of asynchronous arbitration and the endtoend timedelay characteristic can be achieved through simulation on OPNET. The experimental results show that the natural priority whose nodes are higher than the others can take the lead in using the bus, and at the same time, the ETE average delay is increased with the increase of topological distance increases between nodes.

Abstract:In order to meet the needs of the rapid development of domestic military planes，and in the light of the main problems existing in current airborne navigation display system, a navigation display system is designed based on the Vxworks and ARM S3C2440. This paper discusses the system design in two aspects i.e. hardware and software. In hardware, the working principle of the overall structure is discussed. And then the working principle of each module of the system hardware and circuit of every module connection are argued. At last, the working principle of the hardware system is analyzed. In the aspect of software, discussion is focused on the technical difficulties of WindML hunan machine interface programming. Optimizing the program code makes the screen more smoothly, and makes the amount of calculation easily, and more realtime. The results show that the Human Machine Interface of display console is simple and intuitive, userfriendly in operation. And this system is low in cost and is wide in application.

Abstract:Aimed at the problems that the drawbacks of traditional methods are lack of scientific and standardized decisionmaking process, and can hardly configure the optimal test resource, a quick and efficient method based on the grey theory and multiattributes decisionmaking theory is proposed in this paper. Firstly, the grey situation decisionmaking model is built up with overall consideration of influence factors and test attributes affected the selection and configuration of test resource. Then the model is solved through multiobjectives' weighted synthesis, and the attribute weights are used to execute the second decisionmaking. The optimal scheme of selection and configuration is finally obtained. The analysis of the practical engineering example shows that the method is of high operability and reliable and scientific. And this can effectively solve the resource selection and configuration issues in automatic test system hardware integration.

Abstract:Aimed at the differences of code for military aviation and civil aviation in design and construction of the dualuse airport, this paper proposes the several aspects as follows: Firstly,from the perspective of the structure characteristics of the pavement micro and macro, combined with the current specification, this paper respectively discusses the road surface friction coefficient, texture depth and flatness;Secondly,from the pavementtire friction system, combined with the regression formula of field data the paper analyzes road surface roughening mechanism, and combined with the field data contrast, water venting capacity and durability, the paper analyzes pavement groove mechanism. The regression formula is established between the fore groove and rear groove with pavement average texture depth and the friction coefficient. The conclusion is that the average texture depth compared with friction pendulum instrument is more suitable for the cement concrete road surface construction control. The paper proposes some design ideas and construction control index on the surface of the dualuse airport cement concrete pavement.

Abstract:This paper proposes a novel dual band magnetoelectric dipole antenna．Two groups of printed electric dipoles with different sizes excite two resonant bands and a pair of metal patches printed on a substrate，which are connected to the metal ground plane，to form the magnetic dipoles．A microstriptoparallelstripline balun is employed to transfer the unbalanced feed to balance feed so that the electric and magnetic dipoles could be excited simultaneously. The use of this feed method can make the antenna smaller，more compact and beneficial for the integration of the antenna and the feed structure．The results of measurement and simulation indicate that within operating bands 2.29～3.13 GHz and 4.70～5.85 GHz the antenna shows a good directivity, stable and symmetrical radiation pattern, and low cross polarization and low back radiation．

Abstract:The multidimensional assignment model is to utilize maximum likelihood estimation instead of the true target position for constructing the cost function without direct consideration of random error. In view of this problem, a data association algorithm is proposed based on the Renyi entropy. The algorithm is to utilize Renyi entropy to quantify difference of functions between the probability density function of pseudo measurements and the most posterior probability density function for constructing an association cost. The results show that the proposed algorithm can improve the correct association ratio and achieve a good performance as well.

Abstract:In order to solve the problem of how to determine the coupling strength in coupling synchronization method,a theorem of single coupling method between Lorenz systems is proposed. First, by reducing the number of state variables, an improved synchronization method named，i.e. single coupling method, is proposed on the basis of the unidirectional coupling synchronization Then, in accordance with stability theory and Routh-Hurwitz criterion, by detecting the signs of characteristic values reduced from the Jacobi matrix of error system, full conditions are derived for satisfying the coupling coefficient in error gradually stabilizing error at zero. Consequently, a sufficient condition of single coupling synchronization is supposed. Last, the simulation results verify the correctness and effectiveness of the sufficient conditions, and the anti-interference performance is good.

Abstract:The method of overthehorizon detection based on the small aperture array is used to overcome the quite large aperture of the traditional OTHR. Since the performance of signal processing is depressed by using the small aperture array，this paper presents an orthogonal frequency division multiplexing linear frequency modulation(OFDMLFM ) waveform design method. With the aid of the signal model, the range resolution of the coherencesynthetic is analyzed. In order to suppress range sidelobe, the convex optimization is proposed. The simulation shows that OFDMLFM signal can improve the performance of the range resolution. The peak sidelobe level is -26.28 dB and the average of pulse compression is less than -50 dB. According to the result，the capability of noise and interference cancelation are increased, and the target detection performance is improved too.

Abstract:Aimed at the problems that floating solution ambiguity is difficult precisely to deduce from realtime change of baseline parameters in dynamic to dynamic relative positioning， a method is proposed for dynamictodynamic integer ambiguity resolution based on Singular Value DecompositionRecursive Least Square (SVDPLS). In the method, the coefficient matrix of baseline vector is resolved by Singular Value Decomposition (SVD), double difference equation is transformed to eliminate baseline parameters， the floating solution and covariance matrix of double difference integer ambiguity are deduced in realtime by Recursive Least Square (RLS) method，and the ambiguity is searched and fixed by LAMBDA algorithm. The experiment result shows that the proposed algorithm can work out the single frequency integer ambiguity correctly in about 100 seconds, the baseline error within 1 centimeter, and is suitable for realtime solution to highprecision dynamictodynamic relative positioning.

Abstract:Taking GPS/SINS integrated navigation system as an application background in light of the problem that the conventional Kalman filter can easily diverge because of lack of prior knowledge and outliers, an improved adaptive Kalman filtering is proposed.The algorithm is based on the combination of Sage_Huse adaptive filter and fading memory filter which can suppress the filter divergence caused by lack of prior knowledge, and then a compression function which can effectively identify and deal with outliers is introduced,so the divergence problem caused by outliers can be solved.Simulation results indicate that the improved adaptive filtering algorithm can suppress the divergence caused by the inaccurate models and outliers,and simultaneously the filter accuracy of the horizontal positions is improved 6 times and 5.7 times, and the filter accuracy of the height position is improved 2.39 times compared to the traditional algorithms,at the same time it is better in adaptability and stability.

Abstract:In view of the disadvantages of sampling at a high rate and long time duration in the current methods of multiple targets imaging, a novel algorithm of chirp rate estimating and Inverse Synthetic Aperture Radar (ISAR) imaging of Multiple Targets is proposed, combined with Compressive Sensing theory based on sparse sampling. Firstly, a redundancy sparse dictionary is established according to the characteristic of echo signals, the echo signals are decomposed into the sparse dictionary by utilizing Gauss random measurement matrices and focal undetermined system solver (FOCUSS) method to recover the imaging, and estimate the chirp rate accurately. Secondly, the echo separation and the motion compensation are done with the chirp rate estimated. Finally, obtaining the image of each target based on sparse sampling. And the results show that the method is feasible and valid.

Abstract:A novel sparse linear array geometry, i.e. a new nested array, is proposed based on KhatriRao (K-R) subspace , which is capable of increasing the degrees of freedom (DOF) of arrays. The new nested array consists of two uniform linear arrays (ULA), where the spacing of larger ULA is determined by the array length of smaller one. Compared with a ULA providing DOF with sensors, a new nested array is able to increase the DOF to by obtaining a virtual ULA with sensors through KR product in K-R subspace, and thus the increased DOF makes it possible to resolve more sources. In addition, the new nested array is a sparse array, and has longer aperture than that of ULA in equal number of sensors to bring a good ability to resolve nearby targets. The new nested array is one of the arrays, which have the largest DOF increased by K-R product, and the performance of the new nested array is good even under the condition of low SNR and small snapshots.

Abstract:It is very important to build up a kind of complex signal environments by adopting a method of IF injection to improve and train operators under conditions of the complex electric warfare environments. This paper introduces a radar signal environment simulator. First, through analyzing target echoes, deception signals and jamming signals. an overall concept design and a modularization structure design plan for the simulator are proposed, and its performance is tested. The result shows that this simulator can generate echo, deception jamming , chirp jamming signal, barrage jamming, and interruptedspotting jamming signal in realtime, and can switch over them in signal channels. The simulator has a great value for matching the design requirement well, and has practical value.

Abstract:A relative superioritybased alternatives ranking method is proposed to solve the type of multiattribute risk decision making problem. The comparison between two alternatives derives from the jointly function of prospects' gains/losses and risk, so the information entropy and standard deviation are introduced and taken as the risk measurements for the prospect, then the concept of relative superiority based on the difference of expected utility and risk measurements between the two alternatives is proposed to depict the relative superiority degree. And the weight vector and preference rank of all the alternatives can surface from the matrix of comprehensively relative superiority. The cases show that the proposed method is effective.