Abstract:Based on the introduction of the concept of aircraft structural life envelope (ASLE), the basic approach and practical engineering method of determining ASLE by experiments under the baseline operational conditions are presented, as well as the basic approach and practical engineering method of determining ASLE by experiments under non-baseline operational conditions. The determination of ASLE will pave the way for Service Life (i.e. fatigue life and calendar life ) Supervision for Individual Aircraft Structural System.

Abstract:In the use of pulse detonation engine (PDE), using high-energy ignition device, as compared with the traditional methods, is favorable to the reduction in delay time, rise time and deflagration to detonation distance. The experiment shows reduction in delay to ignition by factors of typically 3 in quiescence to more than 4 in a flowing PDE, and other enhancements in performance. And the further experiment shows that if the equivalent ratio of reactants is appropriate, there will be an optimum ignition energy that can make the DDT the shortest.

Abstract:The paper analyzes the infrared radiation characters of the infrared countermeasure bomb and the target aircraft. Based on the characters, the energy equivalent center of the infrared radiation is researched. The method of calculating the radiation strength and the trace of the energy equivalent center are presented, and the method proved to be feasible and available through simulation.

Abstract:The paper mainly introduces the characters of active-disturbance rejection controller (ADRC). The ADRC doesn't rely on the accurate math mode of controlled object and it can compensate the system's inner and outer disturbances. According to the characters of ADRC, the paper provides a new method in UAV's longitudinal channel control. The closed loop system can make the pitching angle accurately tracked and controlled without changing its controller's parameters in different flight states. The ADRC also realizes the velocity loop and the pitching angle loop's decoupling control. The result of the simulation shows that the system is good in dynamic response and robustness.

Abstract:In order to study the form mechanism of Laser Supported Detonation (LSD) in Laser Propulsion, an experiment was made. YAG laser 2J/pulse with pulse - width of 5 nsec, focalized through the convex lens and exploded around the focus. Using the Hi-spec processor and schlieren apparatus in the experiment the emission images of laser sustained plasma and schlieren images of disturbed air field were obtained, and then the duration time of plasma and other characteristic parameters were calculated. By changing the material parameters, the plasma wave's magnitude increased obviously, the duration time lengthened the threshold value of LSD fell distinctly.

Abstract:With regard to the characteristics of flight data, a new identification method of flight data model based on dynamic fuzzy neural network is presented. By on-line learning, the proposed DFNN is learned for a compact network with better generalization ability. The network structure is learned by means of adding or pruning a new neuron, furthermore, the linear parameters as network weights are gained based on the recursive least squares algorithm. Through a great number of observations in a certain sortie, the DFNN method is applied to the identification of the association model of flight data. The test results show that the method is of faster constringency and better generalization.

Abstract:In this paper, a radiant pattern of an airborne monopole antenna is obtained, by comparison with the antenna's patterns in free space, the effect of the aircraft on the antenna's radiation characteristics is analyzed. Based on the result, the variation of the EM fields of the airborne antenna to a fixed position in space is calculated when the aircraft is flying circlewise. In the example given, the variation is 6.5 dB.

Abstract:A simulation - based space entity collision predicting method applicable to all situations is presented. In order to avoid failing in reporting collision and improve computing efficiency, a method that adjusts simulation step self-adaptively is brought forth, and its algorithms are presented in detail. Through giving a typical example, the validity of the algorithms is verified.

Abstract:First, a numerical simulation of the fluid field is performed in the opposite direction of the airplane by using CFD software - FLUENT, so the distribute situation of the temperature is attained. Then, a model of the radiation from the nozzle of the turbojet engine and exhaust gases of the airplane is built. The total radiance and that in the above IR band are obtained by FLUENT, which provides a basis for the IR guidance air-defense weapon system design and application.

Abstract:In view of the phenomenon that the common pavement concrete is prone to crack upon its construction, analyses are made of the causes for such cracking, a new type of pavement concrete is developed by mixing the common concrete with fly ash and polypropylene fiber, and a test with plate specimen is adopted to fulfill the comparative test of crack - proof properties. The results of the test suggest that the common concrete, if mixed in proportion with either fly ash or polypropylene fiber, can improve its crack - proof property but the new-type concrete, mixed in proportion with both fly ash and polypropylene fiber at the same time, can more effectively prevent itself from cracking, thereby greatly prolonging the service life of the pavement.

Abstract:Based on the instruction of the multi-path effect of the approaching landing system, the construction of the scatter model database for the complex environment on the airports was completely demonstrated. According to the principle of electromagnetic scattering algorithm, different scatters select different models. On the other hand, the aircraft diffraction and reflection are simulated correctly. The result indicates that the calculation coincides with the measured result, and the proposal in system simulations is feasible.

Abstract:This paper presents an adaptive neural networks-fuzzy reasoning information fusion system, which is employed to decrease the influence of the uncertainty of sensor state on fusion performance under complex environment. The model consists of confidence estimator and weighted fusion, which is applied to information fusion of multi-mode composite guidance with perfect result and high reliability.

Abstract:To enhance the information from different sensors and improve the analytic and extracting ability of images, an algorithm of image fusion based on the wavelet packet transform is proposed after studying the wavelet packet analysis method. Although the analyzing method based on the wavelet packet is more accurate than that based on the multi-resolution wavelet, with the former method, computing complexity is exponentially increased with the growth of image size. After analyzing the efficiency of image fusion algorithm based on the wavelet packet on the single computer, the inherent complexity and the parallelism of the above fusion algorithm, a parallel image fusion based on wavelet packet in the MPI (message passing interface) framework is proposed. In addition, the efficiency of parallel computing is studied under different conditions as different image size and different cluster size. The experimental result shows that the efficiency of parallel computing is obviously improved and this paves the way for the future design of highly efficient and real-time fusion algorithms.

Abstract:In the design process of some scatter communication antenna, the feed is simulated and devised with high frequency simulation software (HFSS). The far field property of feed is fitted and interpolated, and the directivity pattern of the whole antenna is calculated combining uniform geometrical theory of diffraction (UTD). Through measuring the practical antenna, the results are consistent well, which proves that the hybrid method is of great precise and high speed in the analysis of this kind of antenna. And the method shows a tremendous application space and prospect in the engineering design.

Abstract:A new method, based on the ULWM operator and ULHA operator, of multiple attribute group decision-making is studied in this paper, with uncertain linguistic information of the attribute weights and attribute values. Firstly, the concept of ULWM operator is defined. Some characters of ULWM operator are discussed. The synthesis attribute values of alternatives are concentrated through the ULWM operator. The group synthesis attribute values of alternatives are concentrated through the ULHA operator. Then, compared with the values of all alternatives by the probability formula, the probability matrix is gained. Finally, all alternatives are ranked by a formula to the fuzzy complementary judgment matrix. An example shows the effectiveness of this method.

Abstract:The group decision-making problems with different forms of preference information are investigated. Based on the translation formulas of four types of fuzzy preference information represented by means of real value, interval value, linguistic assessment term and intuitional fuzzy value, this paper firstly makes the information uniform, then the effective synthetic attribute weight is determined based on aggregation operators. Finally, a numerical analysis is given, and the result shows the approach is simple, effective and easy to implement.

Abstract:The relation between the performance of AdaBoost and that of component classifiers is analyzed, and the approach of improving the classification performance of RBFSVM is studied. There is an inconsistency between the accuracy and the diversity of component classifiers, and the inconsistency affects the generalization performance of the algorithm. A new variable ó - AdaBoostSVM is proposed by adjusting the kernel function parameter of the component classifier based on the distribution of training samples, and it improves the classification performance by making a balance between the accuracy and diversity of component classifiers. Experimental results indicate the effectiveness of the proposed algorithm.

Abstract:Cramer-Rao low bound of dissimilar multiple sensors filtering system with measurement origin uncertainties are derived, effects of various parameters on steady state CRLB are analyzed via simulation, and a mistake about these effects in a related foreign literature is pointed out.

Abstract:Spectral envelope conversion is an important content of voice conversion. Based on bilinear transform function, spectral envelope can be efficiently converted even with small training speech database. In this paper, based on LPC analysis and calculating the spectrum converted system unit impulse function, a method for calculating spectrum converted LPC coefficients is proposed, by which the spectral envelope is converted efficiently.

Abstract:By improvement of Zheng's authenticated key agreement protocol, an identity sign-cryptic technique-based authenticated key agreement protocol is proposed. This protocol has the advantage of sign-cryptic technique and achieves the two functions of authentication and encryption in a single logical step. Therefore, it is of high efficiency. Moreover, due to using ID-based public key system, the expense of building and managing public key infrastructure is decreased and the users need not store or transfer public keys and certificate. And again, in our proposed protocol the bilinear pairing on elliptic curve is employed to reach the equivalent security levels with short length key and small computation cost. As a result, the remarkable properties of our authenticated key agreement protocol are low computation cost, narrow bandwidth requirement, and high security level.

Abstract:Intrusion detection system is a newly emerging and promising security measure. Data mining methods have been used to build automatic intrusion detection systems based on anomaly detection. The goal is to characterize the normal system activities with a profile by applying mining algorithms to audit data so that abnormal intrusive activities can be detected by comparing the current activities with the profile. This paper provides a new Intrusion Detection method based on data mining technology and combines fuzzy logic with apriori mining method. By grouping the quantitative attributes in network traffic according to fuzzy set, and by using genetic algorithm to construct the membership functions that state the fuzzy set, the existing "sharp boundary" problem can be avoided if the classic set theory is adopted. The experiment result shows that this combining fuzzy logic data mining method is an effective anomaly detection way.

Abstract:Based on the study of decision content for materiel support and command aided support system, a modeling method for complex system is put forward. Firstly, the process of materiel support activity is described by using IDEF3 method and decision problem on materiel support activity is summarized. Secondly, the IDEFO function modeling for aided support system is established. Finally, the method of establishing information model and dynamic model is pointed out. The establishment of model becomes a stable foundation for the follow-up development.

Abstract:The effectiveness evaluation index system of maintenance support system is established. The multi-level extension evaluation method is used to study the effective evaluation of maintenance support system, by comparison with the results of AHP and the catastrophe evaluation method, the conclusions obtained are on the whole the same. This provides a new method for effective evaluation of maintenance support system and also provides a quantitative basis for decision-making.

Abstract:In order to overcome the shortcoming of the fuzzy numbers membership function in ranking fuzzy numbers in the air defense, the definition of relative membership degree is introduced, and then the relative membership degree deviation is defined. Moreover, a method of ranking fuzzy numbers based on relative membership degree is proposed. Thus, by using this method, the problem mentioned above can be solved.

Abstract:This paper introduces nonlinear Lipschitz-ɑ operators between two metric spaces and those between metric space and Banach space. The invertibility of these operators is discussed. Moreover, the perturbation theory of invertibility is proved.