Abstract:When checking a third fighter aircraft which is in service with the standard of 1797, it is thought that it is more reasonable to get time domain indices such as ratio of peak values uprising time etc. with time response curve obtaining through transferring function of high order system. A method to determine neal - smith criteria with optimization technique is put forward in this paper and the method works very well. By comparing the results calculated out with the actual flying qualities of an aircraft, it shows that some of criteria in 1797 on the short period flying quality of an aircraft are too strict to be met, so when they are applied to evaluating the flying qualities of an aircraft, a reasonable adjustment should be done according to the actual application and some guidelines should be given in detail, in this way, some un-compatible results can be explained very well.

Abstract:A flight simulator is successfully designed in order to solve the problem that the integrate navigation system's core navigation computer couldn't perform system dynamic trial in static state. The simulator based on USB interface is realized by using CPLD and USB interface chip with MCU. The simulator plays an important role in the research of domestic design of the navigation computer.

Abstract:In the process of engine starting, the airflow of every section is in subcritical condition. It's hard to construct a model by using the traditional thermodynamics method. A dynamic identification model is set up in this paper based on Radial Basis Function network, using the flight data records of aeroengine parameter in the process of engine starting as learning samples. The simulation results show that the model has a good dynamic performance and high accuracy, which opens a new way to build the model of engine in low speed.

Abstract:In this paper, a layout of a multi-static radar system is taken for an example to go deep into analyzing the relationship between the modes of localization and the precisions of localization. The precisions of localization of the three modes of localization: distance sum, distance difference and azimuth angle are calculated and analyzed by formulas, and some universal valuable conclusions are gained after simulation by computer.

Abstract:In this paper, an improved ILS receiver based on array processing concepts is proposed for safer automatic landing procedures. The new approach is based on Direction of Arrival (DOA) estimation performed by the UN - MUSIC algorithm. The superior performance of the proposed system with respect to currently employed techniques in the presence of unwanted interferences has been tested in extensive computer simulations.

Abstract:In theory the waveform matching algorithm is deduced in detail. Then, feature extraction and classified distinguishing are achieved for UWB radar returns, and besides, this algorithm is simulated via computer. The result of simulation shows that this radar target recognition method is good in effect, and simultaneously can be easily realized.

Abstract:Based on the modern combat environment and air attack mode that confronted the ground-air missile weapon system, combined with the fire theory of the ground-air missile firepower unit, the queuing model of the combat effectiveness analysis is established, and the statistical equilibrium of the model is analyzed emphatically.

Abstract:Based on the analysis of the national and international development of aimed warhead and the conclusion of its developing direction, this paper establishes a model of missile meeting with target, then gives the analytic expression of optimum detonating delay time, and finally analyzes the result of imitation. It is of a certain reference value to the design of aimed warhead.

Abstract:This paper investigates a search question of a moving target. In the process of the search, the searcher distributes search resources over a search space in order to detect the target at a finite number of time points. The target selects the path from some options in order to evade the searcher. Then the problem is formulated as a two-person zero-sum game, and the method of the problem's solution is given.

Abstract:The model of the active blanket jamming is an important part of environment model library in the radar system simulation. The active blanking jamming is analyzed theoretically, and the model of it is established based on SPW, the advantages and disadvantages are presented based on the simulation results, all of this would be a basis for the radar simulation under the environment with jamming.

Abstract:This paper discusses SNR threshold behavior, the reasons for it's formation, and proposes some methods of reducing the SNR threshold. The advantage of these methods is that the increase in the amount of calculation is not great with the degradation of SNR threshold. The computer simulation results are included to demonstrate the performance of these methods.

Abstract:M- ary spread spectrum technique has been used in many communication systems, including the satellite communication system. Its spread and despread spectrum process is complex, and needs more orthogonal PN codes and more complicated computation. A new M- ary spread spectrum scheme is proposed in this paper. At the transmitter, M PN codes of each user are generated by circularly shifting the prototype spreading code. The proposed receiver can realize despreading with a time-frequency transform domain matched -filter, which reduces computation and PN codes selection difficulty of M- ary spread spectrum system. The performances of the proposed system are discussed and analyzed.

Abstract:The influence of multi-band interference on ultra-wideband (UWB) communication is analyzed in this paper. The closed form of the JR expression is derived based on the Gaussian pulse waveform. The direct sequence spread spectrum communication (DS - SS) and frequency hoping spread spectrum communication (FH - SS) are respectively compared with UWB communication in performance and analyzed in the presence of multi-band interference. According to common variable of the above three communication models, the JR performance curves can be simulated respectively. A comparison based on JR parameter between the multi-band interference suppression capabilities of above three communication models is carried out, which shows that in most cases, the multi-band interference suppression of UWB is superior to that of DS - SS and FH - SS.

Abstract:The modified Chau's circuit is built by actual electric elements, which then is used in the chaos mask communication. The simulation results and the experimental results of the chaotic mask communication based on this modified Chau's circuit are presented respectively, and these results are analyzed simultaneously.

Abstract:For an AGWN channel, based on Log-MAP decoding algorithm, quantization and fixed-point number representation of all the data which are produced during the SISO iterative decoding of turbo codes are analyzed and studied systematically. According to data observation and anatomy of algorithm, with Monte Carlo simulation, this paper presents the fixed-point representations and quatization details of the data such as received information, extrinsic information, the channel reliability value, state metric, etc. By the quatization scheme determined in this paper a better tradeoff between the decoding performance and implementation complexity can be obtained, and the degradation of performance is not more than 0.15 dB.

Abstract:This paper proposes a data link layer protocol stack, FSP on the analysis of various kinds of classical techniques that support the integrated services in VSAT satellite communication network. The design and key technique of FSP are presented, which are simulated to compare FSP and other well-accepted technologies by OPNET, and the result shows that FSP is capable of performing better than the others.

Abstract:With the development of the communication network operation structure, the mobile agent - based network management has become a focus in the research of distributed network management. In this paper, a network management structure model based on mobile agent technology is put forward, and the management domain structure of network management structure model is designed; then the functions of the management domain are discussed in details.

Abstract:MPLS VPN is an important technique for the implement of VPN, which is capable of overcoming some vital shortcomings of IP network and attracts wide attention. Combining the advantages of IPSec with those of MPLS, a security solution is put forward. MPLS VPN is modeled as a discrete event system. Then a simulation platform of MPLS VPN is built with C ＋ ＋The security solution is verified and the result shows that it is feasible.

Abstract:This paper analyzes non-symmetrical RSA encrypting algorithm and PE file format, based on RSA fast key generating method of Derome, proposes a method of validating DIL by utilizing advanced language ASM to compile embedded RSA and encrypting PE executable file under Win32 platform by directly modifying PE file. This method is free from the time consuming Euclidean algorithm, can be implemented by parallel processing, and has a robust safety in practice.

Abstract:This paper proposes a standpoint of fusion development of support vector machines (SVM) and neural networks (NN), and argues that SVM and NN are equivalent in function but different in implementation algorithm. In term of cognitive model, it discusses the guidance effect of NN cognitive model on SVM counterpart development, and simultaneously investigates the concepts and development methods of SVM cognitive model in detail. Finally, it proposes a class of NN algorithm development from the angle of core idea of SVM algorithm.

Abstract:Based on the amendatory Prony method, an algorithm for estimating frequency quickly and accurately is proposed by making use of the noise's non-relativity at different times, and the algorithm is realized in hardware by using the FPGA technology.

Abstract:There is a common characteristic for fade-in, fade-out and dissolve, and it is a linear gradual process in shot change. It is important to detect the gradual shot change in order to improve the video background process and allow automatic parsing of the video for the purpose of editing and database indexing. In this paper, a data - drive method of gradual shot change recognition, such as fade-in, fade-out and dissolve, is given. A model is built for gradual shot change, and then a recognition algorithm based on frame - difference statistical characteristics is presented, finally, evaluations and experimental results are presented.

Abstract:In order to study the synthetic topographical characterization of surface created by abrasive water jet (AWJ) and carry out a detailed research for the process of the surface creating, this paper researches the surface signals obtained by both the contact profiler and a new developed optical instrument. Through wavelet decomposition and re-construction of surface signal, surface features, such as form error, waviness and roughness are separated rationally. Some fundamental issues, such as the selection of wavelet bases and the determination of wavelet decomposition level are discussed in detail. The results of a series of experiments show the efficiency of the wavelet-based method.

Abstract:The coupling between array elements can make the side-lobe higher, the angles of nulls float and most classical synthesis methods inoperative because of its effects on the current of elements. So the amplitudes and phases of the elements current must be adapted to those generating perfect patterns when synthesizing with coupling. Aiming at the element stimulate voltage, mending the current coefficient, and solving by the method of Moments, the nulls meeting certain depth requirement can be obtained. The required step and time are few in this method, and the results of the examples of several types arrays agree well with the corresponding emulation results simulated by Super NEC, which prove that the method is valid and accurate.

Abstract:Using Semi-Analytical Method of FEM to computer three-dimensional infilling wave shape system, this article constructs a counterforce matrix. According to the Semi-Analytical Method of FEM, the placement field is expressed as a combination of the placements in two directions: one is a displacement showed by function; another is a system of algebraic equations used to solve FEM. In the end, the result shows that the Semi-Analytical Method of FEM has the advantages of high precision, quick convergence and easy to program.

Abstract:In this paper, the Bistatic scattering coefficient from one - dimension Gaussian perfect conductor random rough surface is computed by the Moment method in Dirichlet boundary condition, and the basis function is taken as the pulse function and weighting function in the point matching method. A tapered incident wave is applied. By this method, two different spectrums in rough surface are analyzed. The results prove that the simulation of rough conducting surface with Gaussian surface is better in effect, which is a good method of modeling in electromagnetic environment.