Abstract:The compressor blades from class 4 to class 6 in a certain type of engine are taken as the objects of study. Based on the standard ground atmosphere and the aerodynamic parameters such as the pressure, the temperature and the velocity calculated under the condition of the design rotating velocity and with the blade twist law being unknown, the aerodynamic loads borne by the rotating blades are calculated approximately. During the calculation, the energy conversion relations in the course of compressor pressurizing and the expression of stage compression work are used, the fact that the loads borne by the rotating blades are far greater than those borne by the static blades and simultaneously the fact that the breakdown rates of the rotating blades are much greater than those of the static blades are all taken into consideration. In this paper the changes of the aerodynamic loads of blades class 4 to class 6 with the blade height under the condition of the designed rotating speed of the engine are calculated approximately, thus an approximate calculating method for calculating blade aerodynamic load is found, which lays the foundation for the strength checking and the vibration analysis.

Abstract:A distortion generator with a moveable sliding board generates a distorted flow field. The inlet total pressure distortion tests are completed on a dual - spool turbofan engine. Based on multiple segment parallel compressor model, the numerical simulation of the aerodynamic stability and performance of turbofan engine are conducted. The results show that the distortion makes the steady operation range of the turbofan reduce, the engine's thrust decrease, and the specific fuel consumption increase.

Abstract:The fatigue load of an aircraft plays a very important role in determining the service life of the aircraft. A method of calculating aircraft fatigue load is given in this paper, which is applied to a certain type of aircraft and effective in practice. The fatigue load finally used for designing is achieved first by integrating the numerical value simulation results or the pressure measuring test results to obtain the load distribution over and the acting point of load on each part of an aircraft body, and then performing load balance correction according to the equation of motion balance of aircraft.

Abstract:In order to keep the mechanical performance of wings in an aircraft, the strengthened part is analyzed by means of FEM, and the maximum stress at this part is gained. On the other hand, a real structure of the modified part is intersected from an aircraft to serve as the test structure. The result indicates that the calculation coincides with the tested result and the load-bearing performance of the modified spar can meet the requirements.

Abstract:The use of multi-sensor in the radar net and the existence of various kinds of jamming make the state parameters of the target in air very complicated. Based on the character of data, the grey incidence and grey model GM (1,1) are used in processing the measurement data. By adopting this method, the data processing speed is improved.

Abstract:In this paper, a calculation method of the jet engine inlet on radar cross section (RCS) is introduced by means of mode superposition on the basis of the traditional waveguide mode theory. The key of this method is to separate a complex terminal into some simple terminals, and to calculate separately the waveguide mode reflectance and polarization scattering matrix of each simple terminal. Then, RCS of a complex inlet can be calculated by the mode superposition of reflectance and polarization scattering matrixes. The advantage of the method is that a complex mode can be easily piled up by many simple modes and various inlet modes can be superposed conveniently.

Abstract:In the power system of plane, the work point of the carbon-pile voltage regulator is often drifted, so it needs testing and adjusting regularly. A design of a general - purpose carbon-pile voltage regulator automatic adjusting - testing system is presented which improves the original adjusting method. The mathematical model of the system is built up; both the software and the hardware of the adjusting-testing system are designed, simultaneously the result and error of the system are analyzed.

Abstract:Situation assessment is the basis of subsidiary decision-making in anti-air fight. In view of the problem in situation assessment, this paper establishes a model based on IDC of SPA and correlative analysis, and then makes an approach to the problem. The practical calculation and analysis show that the model is feasible and effective in the assessment of battlefield situation.

Abstract:In view of the problem of intercepting TBM in the future air defense war, this paper establishes two queuing models of the intelligence forecasting system and the interception system, in this way, the intercepting efficiency can be calculated. At the same time some methods of enhancing the intercepting efficiency are discussed.

Abstract:In order to improve the reusability and interoperability of air-raid and air-defense simulation system, this paper analyzes the model components in detail, presents an integrated modeling method based on UML and HLA, which is an effective development method for the construction of the large scale complex simulation system with reusability and interoperability.

Abstract:A new mobile mode for ground - to - air missile battalion that adapts to modern antiaircraft battle is presented, in which several important factors influencing the efficiency of antiaircraft weapon--missile in the process of missile battalion mobile transferring are analyzed. And also a mathematic model is built to describe the efficiency of the antiaircraft weapon systems during the transferring. Furthermore, the feasibility of it is verified by solving and analyzing the mathematic model.

Abstract:The advice integration is one of the most important methods for the multi-agent system (MAS) to model and simulate the dynamic complex system. The advice is modeled based on CBR (Case-Based Reasoning System), and a support to the advice integration is added to the traditional agent's structure. Finally, an instance of ASA (Air Support Agents) simulation approach is analyzed and the generality of the model is verified in the process.

Abstract:Because of some disturbances, all experimental data are to some extent contaminated by noise, which will affect and abate the efficiency of chaos time series analysis. So studying noise reduction of time series is very important. The spectral content of nonlinear time series contains strong broadband contributions, therefore, linear filtering in the Fourier domain fails in many cases, e.g. it cannot restrain noises, on the contrary, may lead to signal distortion. This paper introduces a nonlinear state space projection technique developed for noise reduction in chaotic signals, and applies this technique to the analysis of ship radiated signal. The experiment results reveal that the method is feasible and effective.

Abstract:A robust algorithm for beam-forming (SESB) is presented in this paper, which is based on the Eigen-space - Based algorithm for adaptive beam-forming. By expanding the signal subspace obtained with the eigen-structure of the correlation matrix, the novel algorithm can avoid the adapted pattern distortion in the ESB algorithm. Computer simulation and analysis demonstrate that the performance of the proposed algorithm is better than that of the conventional ESB algorithms.

Abstract:Based on the analysis of functions, characteristics and programming methods of Loadable Kernel Module of Linux system, this paper presents some ways to enhance system security by utilizing LKM's characteristics and to keep a lookout for the hachers taking advantage of LKM to intrude into the system.

Abstract:A comparison between Certificate Verification Tree and Certificate Revocation List shows that both of them have the same performance as a whole. An extended scheme of Certificate Verification Tree, which is completely comparable to the former two schemes, is proposed by issuing more short validity certificates to a signer at a time. And this scheme also inherits most of the advantages of the original Certificate Verification Tree. It is demonstrated that the computation time, storage requirements, and communication complexity can be allocated properly according to the specific applications in the design of PKI.

Abstract:Alarm management system is the core of a network management system. The research is mainly made on the design and test of the two modules, alarm management and alarm reception in the alarm system. Through repeated tests, a better method of the test and design of the alarm management system is achieved. Some problems to be solved in the design and test are analyzed.

Abstract:At first, the hidden node parameters of RBF are obtained by the classical clustering method; then those parameters are studied again by the method of steepest descent. The simulation shows that the method can reinforce the RBF approximation quality obviously.

Abstract:In this paper an approach to object extraction in textured images is proposed based on a mask stochastic method in object edge extraction, and its aim is to detect the object hidden in texture. The experimental result demonstrates that the approach is effective in detecting the object hidden in textured image.

Abstract:Analysis and calculation are given to a type of polarizing modulation glass ring optical current transducer. Some factors affecting the measurement are discussed. The calculation and experimentation show that the processing error of glass ring plane and the assembly error of optical element have a direct effect on the sensibility and the measuring precision of the detector (optical current transducer).

Abstract:A conventional local calibration device used in computer is developed for calibrating thermo resistors' dynamical characteristics. The relationship between the temperature response of the surrounding temperature step changes and that of the loop current step heating is proved. Then, a data processing method is found in obtaining the response time constant. In lubrication oil and wind tunnel the LCSR and the surrounding temperature step changes are tested and compared. The result shows that the error of the time constant obtained by using this method is less than 5%. And the time constants of thermo resistor and its shell obtained respectively can be further used to determine the main factors affecting the response speed.

Abstract:On the basis of the unified model, the multi-frequency averaging method is presented and applied to the analysis of the switched converters working on the discontinuous conduct mode. Using the presented method, not only the base wave in a steady state, but also the size of each harmonic can be obtained. The practical simulation indicates that the method is better in logicality, easy in programming and of great precision in computing, furthermore, it is applicable to the steady state solution and the analysis of ripples in the open loop and various kinds of closed loop systems.

Abstract:The piezoelectric ceramics (PNW - PMS - PZT) are prepared by the traditional ceramics process, the phase structure of powders calcined at 850°C is analyzed. The influences of sintering temperature and different components on apparent density ρ, relative dielectric constant εr, dielectric loss tanδ, Curie temperature Tc and piezoelectric constant d33 at room temperature are studied. The results show that at room temperature with the increase of the amount of PZT solid solution in system, εr , Tc and d33 are gradually increased, tanδ is gradually decreased; with the increase of the sintering temperature, ρ is increased in general, εr and d33 are increased, tanδ is gradually decreased but the change of Tc is not obvious. At last, the piezoelectric material with εr＝2200, tanδ＝0.0062, Tc＝235°C, d33＝390pC／N is obtained.

Abstract:In consideration of the factor that the energy of the induced current on a scattering object excited by a plane wave with a Gaussian pulse almost all concentrates on a finite time and frequency-domain, by expanding the response in time with Laguerre function, a corresponding frequency-domain response is attained by using Fourier transform. According to the characters of Fourier transform, the low-frequency and high-frequency responses determine the late-time and early-time responses respectively. In this paper, the early-time and low-frequency responses are generated through the use of a time-and-frequency hybrid method including MOT and MOM and they are mutually complementary and contain all the necessary information. So the whole response can be attained by simultaneous extrapolation in time and frequency domains. The electromagnetic scattering responses in the time and frequency domains of the ideal metal conductors are calculated and analyzed by using this method.

Abstract:This paper uses the basic theory of observation process for analyzing the posterior distribution, approaches the situation when two threshold observers get shrinking, and gives the error estimation of A/D transformer.