Abstract:By an inserted board airflow inlet distortion test, the flow will be reduced to a point with raising the inserted board. The section average total pressure and the average total pressure in the circumferential low-pressure areas are in linear relationship with the air inlet flow. Then, the circumferential distortion exponent can be estimated. The circumferential angle in the low- pressure area just is in linear relationship to the inserted board height. The section steady distortion pressure distribution can be divided into high pressure area, mixing pressure area and low pressure area, each has its own characteristic in distortion and their boundaries are obvious.

Abstract:In view of the maze composite cooling structure tile of combustor, a three-dimensional numerical simulation program is adopted to gain the distribution law of temperature field, displacement field and stress field. The research shows that the numerical simulation method adopted has better veracity and can reflect the tile's thermal-stress coupled field factually. The calculation result shows that the design of this cooling structure is reasonable, the structural strength can accord with the demands under the condition of simulation experiment environment and meet the experiment's demands.

Abstract:Estimating the object threat degree is the key of multi-object attack decision making. In this paper air-combat situation and air combat ability are chosen as the threat indexes. Based on the sum of squares of deviations, an optimal combination weights method is proposed in order to calculate each index's weight, which is contained in many kinds of determining weights methods. Finally, an application example is given, and the result shows that the method is effective in multi-object attack decision- making.

Abstract:A method based on SEA for effectiveness analysis of AWACS for low altitude early- warning is proposed. The fundamental principle of SEA is first introduced, and the problem of effectiveness analysis of AWACS, while performing the mission of low altitude early-warning, is described, with the proposition of effectiveness model of AWACS for low altitude early-warning and the emphasis on investigating the calculation methods of effective early-warning for low altitude which describe how to get the measure of performance from system mapping and mission mapping. The validity of the method is illustrated by an example. This will be beneficial to the following research on integrated system effectiveness analysis of AWAC.

Abstract:Aiming at the problem of evaluating the maneuverability of aircraft which is useful for detection and aviation against submarine, this paper establishes the evaluation indexes collection of the aircraft and the index matrix of samples to be sorted, and uses the first principal component value of samples for constructing an evaluation index of multi-index system and sorts the samples with this method. In an illustrative example, the synthetic maneuverability of different kinds of aircraft is sorted by using the method proposed in this paper. The result obtained is consistent with the real situation. The example shows that the method is effective and objective thus can be used to evaluate the synthetic maneuverability of aircraft objectively.

Abstract:This paper searches the nearest training data set as the training data sub-set in fault characteristics data space, and applies the steepest descent method (back-propagation) to optimizing the parameters of the fuzzy rules in the local model. Then though simulation on Fisher's iris data set and comparison with adaptive neural fuzzy inference system (ANFIS) the average test error is reduced by 15% and the operation speed is increased by about 30%. After a fault characteristics data set from actual aeronautic engine test is put in this fault detection model system, the model system can accurately identify the three kinds of fault states existing in the engine, and the result shows that the fault diagnostic strategy is efficient and available for some fault diagnosis problems.

Abstract:A terminal guidance law based on the terminal sliding mode technology is proposed for the precise interception of exo-atmospheric kinetic interceptor. Firstly, the longitudinal and lateral equations of relative motion are built without considering the kinetic interceptor's attitude motion. Then the nonlinear terms are introduced into the mode designing of terminal guidance law, so this terminal guidance law doesn't have the switch terms that exist in the traditional variable structure guidance law and can ensure the global speediness of guidance system. The simulation results show that the method used in the terminal guidance of kinetic interceptor is effective and it's better than the proportional navigation and traditional variable structure guidance law in robustness and precision when intercepting the maneuvering targets.

Abstract:Based on the study of impulse correction force, this paper establishes both the motion equation of center of mass and the rotation equation of the guided rockets using impulse correction, and demonstrates the feasibility of the model through computer simulation. (1) The correction distance increases as the force increases, and the correction distance is the maximum when the force is 5 000 N. (2) The correction distance increases as the distance between the force point and the center of mass increases, and the correction distance is the maximum when the distance between them is 0.5m.

Abstract:Inverted pendulum system is a complicated and absolutely unstable nonlinear system. This paper provides a dynamic model of it, and gives the control methods based on the State-feedback and Variable Structure Control (VSC) respectively; the comparison based on digital simulation shows that the Variable Structure Control is more effective and robust.

Abstract:At present, the major of the information fusion method is closely related with prior knowledge, that can not always be satisfied in real application scenario. To effectively solve this problem, the concept of support degree is proposed on the basis of exponential attenuation function. Then, two kinds of support degree based information fusion algorithms that do not require any prior knowledge are presented. Finally, the proposed algorithms are adopted to process the measurement values of three radars. The experimental result indicates that the algorithm is good in fusion result. Meanwhile, the algorithm is simple in implementation.

Abstract:In order to resolve the shortcomings of the traditional Kalman filtering, a new method is presented in which the fuzzy reasoning system is combined with the traditional Kalman technology. By monitoring the covariance between abstract residual and actual residual, this algorithm modifies recursively the gain coefficient of the filter so as to adaptively control the Kalman filter. Finally the optimal estimate is achieved. The computer simulation results of the INS / GPS integrated navigation system indicate that the algorithm is effective and practical.

Abstract:A tracking control method is proposed for continuous chaotic system based on the Lyapunov stability theory. Using this method can make the controlled system approach to any reference signal. The structure of the designed controller is independent of that of the chaotic system. The numerical simulations of Chua's circuit, Lorenz system and Rossler system are given to illustrate the effectiveness of the proposed method.

Abstract:The modeling of the system is discussed on Stochastic Petri net (SPN) with the transition subjected to Markov process. The determination of state space, expectation probability and duration of each state, the reliability of the system and the working intensity of maintainers are analyzed through examples. Compared with traditional modeling methods, in the course of analyzing the state space and logic relation among the states and the dynamic process of the system, SPN is discovered to be more effective than and superior to the traditional methods.

Abstract:In order to calculate electromagnetic characteristic of target's DXF models, the model's data format is analyzed, the reading and analysis methods are studied. A sort of simpler quality factor, which is defined as the length ratio between the shortest and the longest edges, is proposed. The real DXF model's quality is analyzed according to the factor and the gained result is as good as in References 1 and 2, the correctness and validity of the factor are proved. Through analyzing, the better meshes generating quality of DXF model is proved.

Abstract:The asymmetric plasma actuator can engender uneven electric field. The plasma moves in the action of electric field force, thus inducing the neutral gas flow through the charge exchange collision between plasma and neutral particle. This paper imitates the paraelectric acceleration process in electromagnetic field with FDTD, analyzes the paraelectric acceleration mechanism and provides a method of improving the paraelectric acceleration and optimizing the asymmetry plasma actuator configuration.

Abstract:A novel approach named adaptive modified template waveform (AMRTW) is proposed in this paper, i.e. an adaptive frequency estimator is used to give the values of the interference frequency and interference band. Based on these values, the adaptive template signal resolving unit gives the rational signal constitutions for receiving template signal. And the UWB receiver modifies the receiving template signal with removing the interference signal component from the receiving template signal. The simulation results show that this new method is more efficient than MRTW method in interference mitigation for UWB pulse radio.

Abstract:A modified state-space equation model is presented, based on a model with double-scroll-like dynamics, which is appropriate for the realization of log-domain circuits. By simulating studies, the result shows that the model has a positive Lyapunov exponent, which verifies the existence of chaos. A chaotic oscillator with the log-domain circuits is also given.

Abstract:A novel spherical helical antenna with wideband, low profile and circular polarized characteristics is studied in this paper. The VSWR, circular polarization and radiation patterns are analyzed by the method of moment, in which the antenna wire is partitioned with helical segments, the subsection triangle function is chosen as a basic function and the pulse basic function as a test function. The analysis results indicate that the number of the unknown matrix to calculate is much reduced and the computing time is much saved, too. Compared with the traditional spherical and hemispherical helical antenna, this novel antenna has better radiation characteristics, which show that it is of great potential value in the field of satellite communications.

Abstract:In this paper, a kind of cylindrical EBG structures applied to base station cylindrical conformal dipole array antennas is studied. The research results show that the directivity of base station antennas is significantly increased, a narrower beam-width is realized in E-plane and a wider beam-width is held in H-plane, which completely conform to the performance requirement for base station antennas.

Abstract:To study the modulation classification problem for M-ary quadrature amplitude modulation (QAM) signals traveled slowly over Rayleigh and Rician fading channels, a new algorithm based on equal gain combining is proposed in the paper. The equal gain diversity model for modulation classification is given in which equal gain combining is used to combine the signals received by multiple antennas. The normalized fourth-order cumulents of the signal at the output of the combiner are estimated, which can be used as modulation classification features. The theoretical values of the normalized fourth-order cumulents of the signal at the output of the combiner for various constellations are derived as the classification criterions. The computational complexity of the developed algorithm is order N, where N is the number of the complex base-band data samples. The theoretical arguments and the practicability of the algorithm are verified via extensive simulations and comparisons with the existing approaches.

Abstract:This paper presents a new web services capability matchmaking method based on constraint conditions, which integrates rule system and semantic matchmaking. The constraint conditions are categorized into two kinds: status -conditions and number-conditions. Two matchmaking methods are proposed separately according to these two kinds constraint conditions. This paper also proposes the software architecture of the prototype and examples to show that the proposed approach is practical and effective.

Abstract:The difference equation for interaction between wild and transgenic mosquitoes is established. The necessary and sufficient conditions that those two types of mosquitoes extinct respectively or coexist with each other are obtained, and the changing tendency of ratio between their numbers is found by means of qualitative theory of difference equations.

Abstract:The key techniques in design and implementation of security attribute service are researched based on CORBA specification in this paper. The implementation framework of security attribute service is proposed and the security attributive service is implemented on the platform StarBus 5.0, and the algorithm of construction and verification of security attribute context is also described. Finally the design and implementation of the scheme proposed in this paper are verified through some cases.

Abstract:The generalized system function, associated with the radiated or scattered fields is presented in this paper, which is constructed by applying a windowed interpolation model-based parameter estimation technique. By analyzing the characteristics of poles of this system function in the operational frequency band, the resonant frequency and Q-value of the antenna and scattering systems are determined. Compared with the generalized MBPE procedure, this windowed scheme can reduce Pade function to only four orders, which effectively alleviates the problem such as ill-condition, low calculation efficiency etc. caused by high-order matrix.

Abstract:Based on the application of OPNET in the modification of a network, the vexed problems and their countermeasures of network simulation application are explored, and the method of simulation modeling and analyzing is also discussed in this paper.

Abstract:SVG (Scalable Vector Graphics) is introduced to the network topology management module, and a SVG based model of network topology display system is presented. The specific module design and realization method are given respectively with regard to data analysis and graphical display. By this method, the network management system software can be used to greatly enhance graphical user interface, which facilitates the integration of other modules.

Abstract:For the peculiarity of the concrete mechanical performance and high-speed impaction, this work chooses the parameters rationally, e.g. material model and contact arithmetic, uses LS-DYNA3D to simulate the penetration. Compared with the experimental results, the whole penetration process and the simulation results are reasonable and accurate.