Abstract:Float point genetic algorithm is used to solve the convergence problem of aero-engine nonlinear mathematical model numerical solution. Simulation shows that the operation efficiency is not high by using the genetic algorithm alone. But by mixing genetic algorithm with Broyden method, the deficiency of each method can be avoided effectively and the convergence is extended with the substantial stability of original efficiency of the model being maintained.

Abstract:The reliability endurance test is an important method of increasing and ameliorating equipment reliability. Using the method of accelerated test to assess reliability life span is a positive aspect at present. In view of the reliability fatigue life of the aircraft auxiliary fuel tank cone, this paper adopts the method of accelerated test to assess its life span. The result shows that the combination method of the accelerated test in workshop and the test-flight in airfield is an effective way of determining equipment reliability life span.

Abstract:Considering the characteristic of flight data's multimode, a new method for monitoring the trend of parameters aiming at aircraft health status evaluation is proposed. First, the filtering process, jump-point elimination and statistic analysis to the flight data are performed during the steady - working state and typical - flight period. Then, by using AR model the value of the parameters is predicted, and finally by using the threshold value comparison method the trend of parameters is monitored successfully. The result shows the accuracy and applicability of this method.

Abstract:The instrument landing system on decimeter wave band is first analyzed in a systematic way. The forming of its navigation information is researched deeply. The characteristics of the system are pointed out and the main technology terms are defined. At the same time, the realization means of the instrument landing system on decimeter wave band are presented. In the end, the technology scheme of producing navigation signal and building radiation pattern is given, which provides a theoretic reference for developing the instrument landing system on decimeter wave band independently.

Abstract:According to the standard of International Civil Aviation Organization (ICAO) about angle error in microwave landing system, a method of bilinear transformation is adopted in designing the digital filter. Then, by using MATLAB software the designed digital filter and the analog filter are simulated simultaneously, analysis and comparison are made for the results of the simulation.

Abstract:It has become one of the most difficult technical problems to solve the distortion of the integrated part caused by the residual stresses during the machining process. The residual stresses in the pre-stretched aluminum alloy plate 7075T7351 are measured by using the crack-compliance method, and the distribution regularity of the residual stresses is analyzed in detail. Furthermore, the measurement done shows that the maximum residual tensile stress of the aluminum alloy plate 40 mm thick is 18.3 Mpa in the direction of its length and its maximum residual compression stress is 17.9 Mpa.

Abstract:Passive DF and crossing location method is an important approach of the interference suppression technology for radar networks. In this paper, the theoretical basis and the algorithm of this method are presented, and the basic composition of the system is formed. By adopting this algorithm in passive DF and crossing location system of TVM guidance mode, a strong anti-jam ability and high precision of tracking can be obtained with the requirement of less information from the secondary station.

Abstract:It is easy to yield the analytical expression of the probability of false alarm with respect to the threshold, but hard to obtain the analytical expression of the threshold with respect to the probability of false alarm. By making use of the perfect properties of radial basis function (RBF) neural networks, such as approaching arbitrary non-linear mapping and quick convergence, a new scheme based modified RBF neural networks is proposed in obtaining threshold estimation. Simulation results show that the proposed scheme is of higher accuracy in threshold estimation.

Abstract:Of late years, steady performance of two sensor hierarchical fusion algorithm with non-full-rate communication was evaluated by Chang K.C., the result indicates that the performance of the algorithm with complete feedback is not so good as that of the algorithm with partial feedback and moreover, in the case of complete feedback, the increment of data rate does not improve the performance. In the research, more attention is paid to the effect of the number of sensors on the steady performance of the algorithm with different feedback mechanism. It shows that for the algorithm with complete feedback, in the case of process noise being relatively small, the increase in the number of sensors does not improve but worsens the performance. This conclusion is an extension and development of the work by Chang K. C.

Abstract:In laser guided bomb based on velocity principle guided usually a weathercock seeker is adopted to detect the laser energy reflected by the target, calculate the errors between the sight line and guided seeker body line and, then guide the bomb to impact the target. The core element of the laser guided bomb is whether the seeker can detect the laser spot or not. This paper builds up the laser guided mathematical model according to the construction and operating principle of the laser guided seeker, and simulates the process of the seeker receiving the laser spot.

Abstract:According to the high-tech weapons′influence on surface to air missile bastion, the paper presents three key points in target damage analysis: building up models according to the requirements of high-tech war; dividing special barracks of aerial defense position in a reasonable way; reflecting the comprehensive principle in the calculating process. It conducts the damage analyses of each single target and the target system separately, still it puts forward the concept of damage coefficient of weapon equivalent and draws the conclusion.

Abstract:A fuzzy system is a kind of system based on knowledge or rule. The development of fuzzy techniques in knowledge processing results in the emergence of extensions of fuzzy sets theory. In this paper, the generation and evolution of fuzzy sets theory, their applications in and effects on the area of AI and knowledge processing are first described. Then, the definitions and descriptions of extensions of fuzzy sets, such as intuitional fuzzy sets, L-fuzzy sets and L-IFS, interval - valued fuzzy sets and IVIFS, vague sets, etc., are exposed. Finally, a discussion is made with emphasis on the relations among the extensions of fuzzy sets theory and all - sets theory, which could probably result in a significant impact on the evolution of the theory, and a hypothesis is proposed on building the links among extensions of fuzzy sets by means of a kind of mapping or operators. The conclusion is that the IFS is one of the most important extensions of fuzzy sets theory.

Abstract:A technical scheme of word data co-transmit in the air-ground tactical data link system is presented. This scheme is based on CS-ACELP speech compress algorithm. In the limited channel bandwidth, multi-channel speech signals can be transmitted at the same time of data transmitting. In the scheme implementation, the two - order end recursion method is utilized to do the search computing for adaptive codebook, and the run efficiency of algorithm is greatly raised. In addition, the peripheral resources characteristics of DSP chip are taken into consideration, and an effective design is made for the hardware interface.

Abstract:A support vector machine is a new machine learning technique developed on the basis of statistical learning theory, and it is the most successful realization of statistical learning theory. For machine learning tasks involving pattern classification, regression estimation, and function approximation, the support vector machine has increasingly become a popular tool. In this paper a survey of the recent new development on the research and application of the support vector machines is made. Some important issues to be investigated in application and the direction of research of the support vector machine have been pointed out simultaneously.

Abstract:A new precise time - integration method is introduced into the analysis of time domain response to switched power converters. By this direct integration scheme the mathematical model is transformed into discrete equations, then by adopting iterative method the exponent matrix is obtained. The method has the advantages of high accuracy and short simulation time, and simplifies the course of analysis. The simulation of example verifies the correctness of this method.

Abstract:A new method of rough measure of the preference degree between action pairs in MCDM is presented based on the Rough Sets theory. The preference degrees of reference action pairs are quantitatively represented by the sets of intervals derived from criteria value of reference action. The comprehensive preference relations of the reference action pairs are approximated respectively by the upper and the lower sets to derive the preference information potential in reference action set in terms of decision rules with no inconsistence found in LRES method. A computational study shows that this new method achieves significant improvement over the method based on the indiscernibility relation.

Abstract:As an important method, PCA has been widely used in many face bases recognition with a good result. To counter its limitations such as larger computation and lower identification, a new method using PCA on wavelet sub-band is presented in this paper, and PCA is applied to the low - frequency sub-band that contains most of the information of the original image. The experimental results show that this algorithm can reduce the computation load and get the higher identification compared with the traditional method.

Abstract:Knowledge mining and discovery is a new technology for decision support system beginning in the middle of 1990s. This is a combination of artificial intelligence, machine learning and database technology. To mine knowledge from large databases, the efficiency of leaning algorithms has to be considered. Applying rough set theory to data mining, the attributes relevant to the mining task can be drawn from databases, and simultaneously simple and concise knowledge can be found effectively. The theoretical basis of this application and the realization of the algorithm are presented and discussed.

Abstract:The effect of oxygenated additive on particle emission is investigated. Particle size distributions in exhausts from a diesel engine fueled by the blended fuel with different proportions of oxygenated additive are measured by a scanning mobility particle sizer and an aerodynamic particle sizer. Coupled with this, emissions of carbon monoxide, hydrocarbon and nitrogen oxide are also measured with an infrared analyzer, a flame ionization detector and a chemiluminescent analyzer respectively. Results show that there is an effect of oxygenated additive on the particle size distribution from diesel engine. Oxygenated additive can significantly reduce particle emission level and slightly modify emission concentrations of carbon monoxide , hydrocarbon and nitrogen oxide.

Abstract:The stability of discrete Hopfield neural networks not only has an important theoretical significance, but also is the foundation of the applications of the networks. In this paper, the dynamic behavior of asymmetric discrete Hopfield neural network is studied mainly in parallel updating mode, and some new stability conditions of the neural networks are given. The obtained results serve the function of further generalizing some existing conclusions.

Abstract:This paper presents a method of detecting various kinds of signals in data - exchange system, introduces a synthetic method of failure removal which can locate failures to specific blocks and simultaneously makes suggestions of improvement.

Abstract:The problem on composition motion of a point between two rigid bodies without restriction contact is interpreted as a sort of noticeable problem in this paper, and some common mistakes easily made in the interpretation, analysis and solution of this sort of problem are discussed.

Abstract:There are disadvantages of traditional vector space model in computational complexity, query efficiency and intelligence. Based on the traditional vector space model, an intelligent N - dimension vector space model (INDVSM) is proposed. INDVSM shows distinct improvement in the computational complexity of document vectors by using a refined algorithm based on local information, and it takes the user's clicks as feedback to tune the initial vectors of documents and queries. Meanwhile the tuning algorithm is also presented and these two models are compared theoretically.

Abstract:Based on the impulse response model of a point target of a side - looking SAR and by using the Tree-step method with directly processing the original echoes in their corresponding time - domain and frequency - domain, detail analysis and induction of the Fourier transform of azimuth in chirp - scaling algorithm are described with the finding of error source of the algorithm and with the providing of the expansion technique of the Tailor series. The paper has a significant effect on the steps analyzed next.

Abstract:The tests of thermal shock and static oxidation are done to C / C composite coating processed through soaking, coat brushing and solidifying. Then the coating's anti-oxidation and mechanism invalidity are discussed through the contrast and study by using SEM and TGM. The result shows that microcracks in the coating are the main cause for coating invalidity, so the thickness of C / C composite coated on the brake should be selected within 0.03 to 0.05 mm.