Abstract:The survivability of engine compressor is determined by the ability of enduring distortion. The distortion mainly includes total pressure, total temperature and combination of the two. Their numerical relation is of uncertainty, and can hardly be simulated by experiment on ground, especially the combined distortion. The effects of these distortions on single-rotor engine and double-rotor engine are varying. To simulate digitally the propagating processes of inlet combined distortion of total pressure and total temperature in a single-stage compressor with high loading, the paper establishes a three-dimensional compressor model, then simplifies and solves the three-dimensional Euler equations by an assumption of infinite rotors and stators and modeling the blades characteristic just by the body forces. The simulation results show that when the combined distortion is passing through the rotor, the intensities of the total pressure distortion and the total temperature distortion are increased by 13% and 13.5% respectively, and obviously higher than those of them before combination. The results also suggest that the circumferential distortion coverage vary very slightly under the condition of both distortion patterns, i.e. inlet total pressure distortion, total temperature distortion, and their combination.

Abstract:The analog controller of a certain turbofan engine generally exisits the defects, in practice, such as that it doesn't match the engine in life-span, is poor in monitoring faults, gives the wrong alarm and so on. In order to solve these problems, taking the Digital Electronic Controller (DEC) as a studying object, we designed the hardware and software structure of the DEC. And also we designed two hardware systems to enhance the reliability of the DEC. The two hardware systems worked at the same time and the backup system received the main system's information every moment, thus keeping the switch process stable. Finally the experiment result of the DEC is given. The result indicates that the research and argumentation for the design of the DEC is reliable and reasonable.

Abstract:In order to solve the strong coupling among control variables of aeroengine，a system of multivariable decoupling control based on fuzzy RBF network for aeroengine is presented.Multivariable decoupling controller of aeroengine based on fuzzy RBF network is designed. Parameters of PID controller and weight-value are adjusted online respectively by fuzzy RBF network and Delta rule to achieve the best control.The control system is simulated by computer in allusion to a nonlinear model of a certain aeroengine with unmodeling dynamics and random interferes such as noise, etc. Simulation results show that the system has satisfactory dynamic performance and decoupling speciality and the method is applied with no necessity to know the accurate model of aeroengine and has perfect self-adjusting capability to the nonlinearity and uncertainty of aeroengine.

Abstract:In order to deeply understand the heat transfer mechanism of the channel with side-outflow, a transient measurement technique of using narrow-band thermochromic liquid crystal is employed to determine heat transfer characteristics on the inner surfaces of trapezium channel with ejection through the suction holes. Experimental studies are carried out to investigate inner surface Nusselt numbers under various spaces between holes, Reynolds numbers and suction-holes-flow ratios. The result indicates that the increase of space between holes has weak influence on surface average Nusselt numbers, but makes the Nusselt numbers distribute more uniformly and the heat transfer intensity is enhanced with the increase in inlet Reynolds numbers. With the increase of the suction-holes-flow ratio, heat transfer are declined obviously in the same position along the main flow, and the surface average Nusselt number is also declined.

Abstract:In order to realize the auto control of ATC, it is necessary to discuss the scheduling and the time interval control of aircrafts' arrivals. This paper gives a detailed analysis of the process of aircrafts' arrivals and expounds the features of the mixed system integrated by CTDS and DEDS, which is composed of airspace, fairway, aircraft, ATC. And the analysis of the system dynamic performance is transformed into the Scheduling of DEDS and the integration of random dynamic system. The great algebra is adopted to schedule the aircrafts, and the minimum variance control is used to depress the intervals. The simulation result indicates that the integration of CTDS and DEDS is very effective, which becomes a new way of application in ATC.

Abstract:Automatic carrier landing system modeling is the key part of construction of simulation system. Firstly, the fundamental of automatic carrier landing system is expounded. Then, on the foundation of automatic carrier landing guidance and control structure, the wave and carrier deck motion equations, carrier air wake model, deck motion compensation model and aircraft induct model are established. Finally, the simulation modules are divided with the blocking design concept in terms of different functions, and, the input and output paths are defined. The design of carrier landing simulation system is accomplished by constructing the simulation program flow.

Abstract:Based on the analysis of the air strike made by a formation of UCAVs, the deployment optimization of the formation is discussed. Firstly, the attacking process is analyzed based on the real word scenario. Secondly, the Continuous Time Markov Chain theory is introduced to model the basic models and the probability transient models of the UCAV combat process. Thus the UCAV formation campaign result can be forecasted. The Multi-attribute method is used to integrate the data gained previously and the optimized deployment can be attained.

Abstract:In this paper, the calculation method of abort take-off decision velocity, when one engine failed during aircraft take-off running in military airfield is studied. An iteration searching algorithm of calculating the abort take-off decision velocity is put forward and the aircraft abort take-off decision velocity calculation is programmed. In order to test the above iteration searching algorithm, 2 kinds of abort take-off decision velocities of a certain aircraft are computed. Furthermore, the computed results are compared with the flight-test results. The computed values are respectively 71.8 m/s、76.6 m/s, and the corresponding results of flight-test are 73m/s、78 m/s. The relative errors between computed values and flight-test values are 1.6% 、1.8%. The results indicate that the iteration searching algorithm is precise and effective for the abort take-off decision velocity calculation.

Abstract:Radar high range resolution profile (HRRP) contains target structure information, and RATR based on HRRP has become a hotly researched topic. As high dimension of HRRP, the method of independent component analysis (ICA) is proposed to extract some features of HRRP, which is decomposed in the field of "base signals", and the coefficients are extracted to form vectors as the target's feature vectors. The Back-Propagation Network (BP) is employed as the classifier. As the classifier may classify the non- depository target sample, the output of BP network is encoded and the refuse-recognition threshold is proposed in this paper, a new classifier is born when the refuse-recognition threshold is adopted. The classifier can refuse the non- depository target samples and put the depository target samples into its class correctly. The simulation of some targets echoes is done by finite difference time domain (FDTD). The experiment results show that the method proposed performs well.

Abstract:The research for coplanar-waveguide transmission line has become an important project recently due to its advantages such as low profile, light weight and low cost. Meanwhile, along with the requirement of developing the communication equipment into a mult-functional and miniaturized one, dual-band antenna also attracts more attention. In this paper, a CPW-fed dual-band antenna is proposed, and the working principle of it is analyzed, consequently, the relation between working frequency and geometry sizes is obtained. And then, some key techniques and notes about FDTD are introduced, such as the setting of source, modified technique of near-field to far-field and setting of radiation boundary. Compared to traditional setting source, adopting mode match method can decrease the computation time. Finally, the computed results by FDTD and measured results are given, both of which have a good agreement at the working band. It has guidance meaning to design this kind of dual-band antenna, according to dual-band mechanism proved by electric field distribution. At the same time, the working mechanism of the dual-band is demonstrated by electric field distribution, which shows a guidance meaning to the parameter selection in the design of this kind of dual-band antenna.

Abstract:It is very difficult to make trajectory correction for high-speed rotating projectile because of rotating characteristic, which can not be solved by adopting the traditional correction projects. Aimed at this technology nodus, a new type of trajectory correction technology project is presented based on piezoelectricity pottery intelligent material. According to the idea that the warhead can act, the warhead correction mechanism is designed. The adding electricity mode of piezoelectricity pottery pole is regulated by detecting rotating frequency of warhead. Consequently, the flexions of the relevant pottery poles are controlled to ensure that the warhead should keep fixed directional deflection in rotating condition. Thus the rotating problem is solved. The system composition and work principle of correction projectile are also discussed amply. Simultaneously, the exterior trajectory mathematic model of correction projectile in ideal condition is founded, and the trajectory curve and detailed data are gained by simulation and calculation. The result shows that the correction project is effective and feasible.

Abstract:Spare parts are the important material basis of the usage and implement of equipment, and the estimation of the spare parts consumption is the core question in formulating the support plan, which will directly affect the performance of the follow-up work including the raising, the assignment, the storage and the appropriation. According to the history consume and the source of navigation equipment maintenance spare parts characteristic, using simple move in average to correct the historical data, adopting the season exponent to forecast the maintenance consumption of spare parts, and testing the forecasting accuracy with the model of GM (1,1).As a result, the certain navigation equipment consumption numbers of spare parts in 2008 are respectively 209 and 214. The two forecast results differ within 3%.Through the comparison between the two forecast methods, different use conditions are generalized, which can guide the further research of the forecast of spare parts.

Abstract:Aiming at the fact that the dependence of modern high-tech warfare on the command and control system is increasing, and that the command and different control system itself characteristics and the different mission requirements make the evaluation effectiveness unstable, a dynamic evaluation model with the matching degree of system space and mission as the target is presented, in combination with the Air-based command control system function, characteristic and application research, on the basis of command control system flight-test data illustrating the broad applicability and real-time effectiveness of the warfare with the Lanchester Equation. By using this method, the operation and the mission of the system are combined together to calculate the relation between the trajectory of the system property space and the mission -required trajectory according to the numeric area of the system in certain circumstance, and finally the whole measurement of the Air-based command control system is given. The method makes up the evaluation difference caused by the unreasonable choice of mission property. The simulation results verify the validity and rationality of the method.

Abstract:For stealth aircrafts and tanks, the discontinuous characters such as gaps are important for RCS(Radar Cross Section) reduction and control. Basing on CFIE (Combined Field Integral Equation), a program using MLFMA (Multilevel Fast Multi-pole Algorithm) is developed. The bistatic RCS of metal sphere by Mie series solution and the experimental curves of a multi-gap plate are compared with computational curves to validate the correctness of this program which shows that the program can be used in investigating the scattering from discontinuous characters in aircraft surface. The relation of single-gap, three-gap and incoming frequency is researched by MLFMA. When the incoming frequency is greater, numerical results show that the electromagnetic scattering enhances and the RCS arithmetic average increases for single-gap and multi-gap; when the incoming angle is small, the average value increases fast, for single-gap plate, the curves are similar for different frequencies and the second crest of curve moves far away from the major crest, scattering from multi-gap has coupling performance and the curves change sharply beside the characteristic of single-gap plate. The coupling performance is gained by the superposition of different phases of three single-gaps, when frequency increases, the position of scattering superposition changes, at the same time, the effects of couple and surge will be obvious. This conclusion can find its application in the design of reducing the RCS of scattering from the gaps in aircraft surface and thus improve the stealth performance of aircraft.

Abstract:In this paper, a laser induced air plasma channel antenna (PCA) for high power microwave weapon is presented, and the dispersive characteristic for normal modes of PCA is analyzed. An approximate electromagnetic model of PCA is created. Starting from the wave equations for the longitudinal components in generalized cylindrical coordinate, the relations between the transverse components and the longitudinal ones of the electromagnetic fields are given. The strict characteristic equation of PCA is deduced by applying the boundary conditions of electromagnetic fields. In the limit cases, the results obtained in this paper are consistent with those given in the literature through comparison, which shows that the results of this paper are correct and effective. Finally, the dispersive curves of PCA are calculated, particularly the variations of their propagation properties with plasma parameters, channel radius and velocity of movement are discussed, which has set up a solid foundation for the development of the antenna.

Abstract:The Information Grid (IG) presented in this article is aimed at providing different units in the multiple virtual organizations (VO) with uniform information safely and rapidly, accurately and reliably. Its security frame takes up the designing idea and implementation of GSI, especially in communication protection, authentication and agency certification mechanisms. Yet the GSI authorization is not suitable for information grid stream as it is too simple and its supplement of the authorization mechanism CAS is too centralized. According to the Role-based Access Control (RBAC), the VO authorization service strategy (VOAS) is presented, by which the problems of the delicate authorization and extensibility of globus are solved. The result of simulations shows that the VOAS strategy will not affect the efficiency of the system, and instead, the complexity of the accessing control is reduced.

Abstract:Aimed at the questions in face recognition by using single classifier, such as the time consuming of single classifier detection, and the significant of face image extracting after detection etc, this paper proposes a method based on Adaboost algorithm to handle it. The classifiers based on the facade and the eyes. First, we screen out the most probably facial area by the Cascade algorithm, then, we detect the facial area with the classifiers, finally，we will perform the precise positioning to the face image with the help of detected distance of eyes and angles, and as the facial pose side effect to the face recognition rate. We correct this problem according to the eyes positions. As the results of experiments indicate the proposed algorithm could detect the face image accurately from the whole image without sacrificing the algorithm running time, and it has practical definitely.

Abstract:When the adaptive centroid tracking algorithm is used to track an extended target, object missing may appear. For this reason, a synthesis predictor which consists of a three-point linear predictor and a five-point square predictor is proposed and added to the adaptive centroid tracking algorithm to predict the location parameters of the tracked target. And the histogram distribution function is computed by estimating the proportion of background in the object window. Then, target pixels can be separated from background image by employing Bayias decision to classify target pixels and background pixels of image in the window, and the centroid coordinate values can be obtained. The improved algorithm can be used to realize the tracking from the small target to the extended target availably with high stability, reliability and precision, which will not be affected basically by the target changing of scale and rotation. The experiments also show that by using the improved algorithm, the problem of target missing that appears when using the original algorithm to track an extended target can be overcome, thus the availability range of the adaptive centroid tracking algorithm is extended, and its tracking precision is improved. The algorithm can provides a useful reference for improving attacking precision of missile guiding at last stage.

Abstract:First, the operating principles of TDCS transmitter and receiver are analyzed based on the basic idea that the system can avoid interference by cooperative sense of transceiver. The Average Bit Error Probability of system in Interference Suppression with MPSK modulation is derived mathematically after the transmitting and receiving mathematical model with symmetrical spectrum was given out. Then, the mechanism of Interference Suppression in TDCS is analyzed and it is found that the system performance will suffer from loss in two aspects: transmitting power loss and receiving additional white noise and interference power. Finally, based on MATLAB, the performance of interference suppression is simulated under conditions of fundamental functions mismatch, single tone, multi-tone and partial spectrum band interfering. The results of simulation and the theoretical results are identical, and the performance of TDCS are better than Direct Sequence Spread Spectrum system in single tone, multi-tone and partial spectrum band interfering.

Abstract:In Pawlak rough set model, an element is in a set, or not in the set, or possibly in the set. A subset of objects, possibly in the set is called boundary of the set. In the research on Pawlak rough set model, less is paid to the research of the boundary issue. In this paper, two objects with a few minor differences in the degree of membership in a set are viewed in the same level. From this view a partition of the boundary of a rough set is obtained and the concepts of band rough set and band distribution reduction and maximum distribution reduction are presented. The judgment theorems, discernibility matrices, equivalence condition of core attribute association with band distribution reduction and band maximum distribution reduction are given .Band rough set model is a generalization of the Pawlak rough set and of the variable precision rough set model.