Abstract:Aimed at the problem of fatigue test to prolong life for aging aircraft, the method of determining fatigue test period to prolong fatigue(durability) life for old aircraft is put forward. The three different conditions were analyzed for choosing the fatigue test loadings; Based on the actual flying hours, the total equivalent flying hours were calculated by damage equivalency principle for service aircraft; The fatigue scatter factor of residual fatigue life was analyzed by numerical simulation based on fatigue life distribution, and the fatigue test period for aging aircraft was determined; Finally, this method was illuminated by a calculation example.

Abstract:This paper analyzes lading procedure of planes in plateau. In view of taking the converted friction coefficient as its model being not suited for calculating a plane slipping length in plateau airfield by the existing standard method, the paper establishes a mathematic model on a plane landing at plateau airfield under the condition of the influence of break performance and the location, and puts forward a calculation method for friction coefficient based on relationship between the velocity and the friction coefficient in breaking, And the paper writes a plane slipping length progress in language Visual C++. Through on-site test in plateau, maximum absolute error of test length and the computed length measured practically by type-I aircraft does not exceed by 48 m, and its maximum relative error does not exceed by 2.7%; the maximum absolute error of test length and the computed length measured practically by type-II aircraft does not exceed by 100 m, and the maximum relative error does not exceed by 4.2%. The result shows that the calculation model can be used for calculating slipping length in plateau airfield, and the model is high in precision and is wide in calculation scope.

Abstract:Aiming at the problem of multiple UAVs confliction resolution, a scheme based on modified artificial bee colony (MABC) algorithm was proposed. On the basis of the artificial bee colony (ABC) algorithm, the probability function and searching mechanism for the onlooker bees are modified to make the best solution play the role of guidance to enhance the exploitation capability and improve the convergence performance. The abilities for exploration and jumping out from local optimum are kept. Both of heading change resolution and speed change resolution are utilized to solve the confliction. The results demonstrate good performance for the convergence speed, running speed and the fitness value of best solution when compared with genetic algorithm.

Abstract:Based on nonlinear dynamics theory, this paper analyzes the stable field and roads led to chaos of aircraft vertical maneuvering at high angles of attack, analyzes flight stability of aircraft at the high angle state and puts forward the stable field of vertical maneuvering under various matching parameter on the basis of aircraft vertical maneuvering equation. Regarding rudder angle and quality as variable parameters, the chaos movement is analyzed by developing the heteroclinic orbit based on Melnikov method. This provides a theory foundation for the control of aircraft vertical maneuvering at high angles of attack under various conditions.

Abstract:Compared to the traditional passive chaff jamming, the radiating on chaff compound jamming can enhance ability of self-defense and survival capability of fighters in battlefield. In order to study the jamming effectiveness and strategy of radiating on chaff compound jamming in countering active radar AAM, by using a typical air battle situation model, this paper, based on velocity deception condition, analyzes the advantages of compound jamming over the traditional passive chaff jamming in countering active radar AAM in frequency. The paper proposes a method of frequency modulation in cooperation with fighter's motion to greatly enhance the efficiency of compound jamming velocity deception on active radar seeker. The simulation results show that this method is efficient in velocity deception jamming, the effectiveness of this method is verified, and has a guiding role in practical air battle.

Abstract:In view of traditional data-centric radar warning technology failure in building up a model of Multi-function Radar at dynamic state and analyzing signals effectively, a mathematical model is established by utilizing stochastic context free grammar(SCFG) to signal production mechanism of MFR, and on this basis SCFG production rules and MFR′s state transition matrix are estimated by EM algorithm, MFR′s operation state is estimated by Viterbi algorithm. The paper also studies the effect of grammar initial values on the algorithm. The simulation results show that the use of the method can effectively estimate MFR system parameters under condition of giving a proper initial value, and the correct probability of the state estimation can come to about 92%.

Abstract:In order to realize the miniaturization of filter, a complementary split ring resonator (CSRRs) is loaded on the upper- surface of substrate integrated waveguide (SIW) and half-mode substrate integrated waveguide (HMSIW) to reduce the original cutoff frequency. This paper analyzes the influence of parameter variation and element number of CSRR on the transmition performance so as to design novel miniature filters of SIW and HMSIW integrated CSRRs. The measurements show that the relative bandwidth of HMSIW filter is more than three times as wide as that of CSRR-SIW filter, i.e. about 10.24%, and the effective circuit area of it is only 31.8×11.3mm2, i.e. about half of that of CSRR-SIW filter. The result shows that the designed filters are effective,and these two kinds of filters can be widely used in microwave and millimeter-wave systems.

Abstract:Aimed at the insufficiency of the traditional trajectory prediction, an improved method of trajectory prediction based on subsection is given. First, the general method of trajectory prediction in free phase is introduced, the causes of trajectory prediction error are analyzed. Then an idea of subsection is put forward, which turns the prediction end point of the former part to the prediction start point of the next part for the purpose of reducing the accumulation of prediction error, in this way, the improved method of trajectory prediction is obtained. Finally, the relevant algorithms and processes are simulated and analyzed, the results show that this method is reasonable and effective in reducing the error of trajectory prediction.

Abstract:A method of designing a compact circularly polarized (CP) patch antenna is proposed based on a composite right/left-handed (CRLH) transmission line (TL) unit-cell. The CRLH TL unit-cell includes a complementary split ring resonator (CSRR) nicked at antenna floor for realizing inductance in parallel and a gap slotted at the center of a sticked plate for realizeing serial capacitance. The CSRR can decrease the TM10 mode resonance frequency, thus reducing the size of the proposed antenna. Simultaneously, the asymmetry of the CSRR brings about a parasitical mode which crosses the +1st-order mode orthogonally by changing the slot radius. The combination of these two orthogonal modes with 90° phase shift makes the proposed antenna form a CP property. The experimental results show that the size of the proposed antenna is 0.389λg×0.389λg, and the impedance bandwidth and the axial ratio bandwidth are of 16.08% and 1.52% respectively. Moreover, the proposed antenna is designed without impedance transformer, 90° phase shift and ground via, and is easy to design and process.

Abstract:To make full use of the operations capability of anti-missile system, this paper discusses multi-dimensional attributes match problems between tasks and multi-resource, and describes multi tasks assignment problem focused on task. Considering the resource application in anti-missile operations, the paper analyzes the multi-dimensional attributes of operations tasks and resource. By introducing resource capability load coefficient, the paper defines a vector distance between the task requirement and the resource capability. Taking the resource redundancy and the cooperative load minimization as an optimization principle, the paper establishes a task assignment mathematic model. Based on improving the multi-dimensional dynamic list scheduling algorithm, the paper designs detail calculation steps and determines the task priority about selecting resource. By way of analysis and verification, the method is feasible and provides a new train of thought for the study of task assignment problems.

Abstract:A novel resonant-type composite right/left-handed transmission line and its correlative lumped-element equivalent circuit model are presented based on regular hexagon complementary single split ring resonator pair. The effective mechanism of its transmission lines is further defined, the control of the resonance frequency and that of the transmission band are realized through analysis of the structure parameters. A perfect balanced condition at 4 GHz is accomplished for the novel CRLH TL, and its impedance bandwidth comes to 1.85 GHz (3.61~5.46 GHz), and the relative bandwidth comes to 40.8%. The circuit model is analyzsed in depth by adopting transfer parameter matrix and Bloch-Floquet theory. A high coincidence of parameters' results of the circuit model and the electromagnetic simulation proves the correctness and efficiency of the circuit model. And a balanced condition is extracted. The negative refractive index and the backward wave propagation are demonstrated by the effective electromagnetic parameter retrieval.

Abstract:A novel monolayer frequency selective surface with dual-stop-band is presented, and this new structure is composed of circular aperture element and overlapping Y loop element to obtain these dual-stop-band characteristics by utilizing the coupling of the two elements . The spectrum domain approach and the electromagnetic simulation software are used to analyze the characteristics of the structure. The results show that the structure FSS forms two transmission prohibited bands with -5 dB within a lower stop band (between 13.4 GHz and 16.3 GHz) and a higher stop band (between 19.3 GHz and 28.4 GHz) respectively, and the new structure is good in angle stability and polarization stability. The novel FSS structure has a great application potential in the antenna multiplexer of different-frequency, radar anti-jamming and the realization of stealth of the antenna radome.

Abstract:By using transient EM scattering theory and electromagnetic wave superposition principle, and pulling-in radar fuze transfer function under dynamic effect based on the mode of multi-point scattering, this paper analyzes the target scattering properties of the ultra wide band radar fuze under the dynamic effect, builds up the target IRF, analyzes the relationships between the target's direction of electromagnetic radiation and the pulse width in simulation , and obtains how the synthetic pulse wave formed through undergoing one-dimensional UWB array radiation by Gaussian monocycle to select appropriate array beam parameters . The research is of some significant value to the design of UWB radar fuze.

Abstract:Rotor inter-turn short circuit fault is hard to be diagnosed because mathematical morphology filter process stator current is not ideal. The method of PSO-adaptive mathematical morphology filtering is used to wipe out the noise interference. Firstly, the best weight coefficient of open-close and close-open operation is found by using PSO, and the best de-noise mathematical morphology filtering is built. Secondly, a fault diagnosis method of taking the wavelet packet entropy as a fault character is proposed combined with wavelet packet analysis and information entropy . Finally, the filtering effectiveness of the de-noise result of PSO-ADMMF and that of the conventional mathematical morphology are compared, and the wavelet entropy after de-noise is figured out. The result shows that the method is useful and effective.

Abstract:On the basis of analyzing the difficulties of RFEC used in detecting non-magnetic plate, the remote field effectiveness is formed on an object of flat geometry by using a type-U component. The principles of optimization design are obtained through analysis of the influence of materials of the UTC, the length of the UTC and the thickness of the UTC. The research of this paper is of some important theoretical meaning and practical value for promoting the application of the RFEC technique and to the detection of the nonmagnetic metal plate.

Abstract:A miniaturized ultra-wideband antenna is designed in P band. The antenna is fed by a pentagon coupled feeding structure. An improved rectangular slot with saw-tooth edge is etched on the ground. The results of parameters show that the bandwidth of the designed antenna is 293.4~830.3 MHz with relative bandwidth 95% and the return loss is less than -10 dB. The size of the antenna is ( is the wavelength of the lowest frequency). The average gain is over 3dBi in the operating range and the antenna is a kind of omni antenna. The antenna is a planar construction and is simple in shape and easy in conformation. A sample antenna is fabricated and tested. The experimental results are in good agreement with the simulation results.

Abstract:In order to solve the problem of targets detection underground, an imaging algorithm is proposed based on the model of electric quadruple radiation. The lack of back-projection algorithm is analyzed qualitatively, a mathematical model of the underground target imaging, which proceeds from the effectiveness of underground targets imaging and delay characteristics of electromagnetic wave propagation, is built by improving the model of electric quadruple radiation, and the implementation process of the algorithm is given based on the derivation of time-delay compensation formula. MATLAB simulation verifies that the improved back-projection imaging algorithm is effective in detecting target underground and corrective in realizing the time-delay compensation. Then the algorithm is applied to the imaging of holes and landmines hided in the rock soil mass as well as to the urban pipeline underground, the effect of undulating ground and noise to imaging results is also analyzed.

Abstract:With the continuous expansion of network scale, evaluating the performance of IP network can help guide network design and provide support for improving the operation of the network. Aimed at the shortcomings of the fussy method and projection pursuit method, a new grey fussy evaluation method is put forward. Five key indexes to influencing the network performance are selected firstly, and the correlation degree of each evaluation index is obtained by using grey relational analysis, which is used as index weight set through normalizing. And the fussy relationship matrix of index set to the comments set is constructed after the fussy calculation is performed, finally the performance evaluation and the ranking of the seven networks are completed. Compared with grey correlation, TOPSIS and projection pursuit method, the result shows that the inner relationship of index is reflected in the results of evaluation, the algorithm is more objective in determining the weight and the specific value of network performance is given. The algorithm is simple, and provides a new idea for the network performance evaluation.

Abstract:Evanescent wave in total internal reflection has special characteristics and important applications. It is very necessary to research on the characteristics of the energy flow of evanescent wave. But the existing studies are simple or incomplete. In this paper, based on the theory of electromagnetic field, the mathematical expressions of electric field intensity, magnetic field intensity, energy flux density and average energy flux density(AEFD) of the evanescent wave are derived, as the incident light is linearly polarized. By numerical computation, the links between the modulus and direction of AEFD of evanescent wave to the incident angle and incident light vector direction, are analyzed. The conclusions include that the energy flow of evanescent wave is limited within a thin layer near the interface of media, the modulus of AEFD is influenced by incident angle, and there is an angle between the direction of AEFD and incident plane, as well; only as the incident light vector is parallel with or perpendicular to the incident plane, the direction of AEFD of evanescent wave is in the incident plane. These mathematical expressions of these physical quantities and conclusions are helpful for understanding the evanescent wave and doing the related studies.

Abstract:A novel logical-based similarity motion retrieval method is proposed for meeting content-based motion retrieval. Firstly, the self-organizing mapping (SOM) algorithm is used to find the best matching units (BMUs) in accordance with the order data specially designed for human body motion, and then, the encoding method is implemented to establish the motion sequences descriptor based on the symbolic aggregate approximation algorithm. Further more, the SAX-based descriptor is used to build the index mechanism and matching. Finally, the proposed method is used to retrieve motion data. The experiment results show that the proposed algorithm is effective.

Abstract:Optimization of meta-materials with the genetic algorithm is one of the most effective methods in the design of meta-materials in recent years. An integral system with interactive simulation of MATLAB and CST Microwave Studio is developed, and the main program of genetic algorithm is written in MATLAB with simulation and computation in CST to realize optimization of meta-materials by genetic algorithm with power of global optimization. Taking the compact second-order frequency selective surface optimization for example, the thinking of design is verified based on penalty function genetic algorithm, and a good effectiveness is obtained. Compared to the previous realizing way, this method is simple in programming operation，better in generality，and only needs a short circle design, simultaneously the method can be applied to other kinds of meta-materials.

Abstract:设H为无限维Hilbert空间，T为H中的有界线性算子，T~λ，T~λ(*)分别表示T的广义Aluthge变换和广义*-Aluthge变换，其中λ∈(0,1)。主要利用分块算子矩阵的方法研究了T~λ和T~λ(*)的Drazin逆及Moore-Penrose逆，证明了对任意复数μ有：①T~λ－μ Drazin可逆当且仅当T~λ(*)－μ Drazin可逆；②T~λ－μ Moore-Penrose可逆当且仅当T~λ(*)－μ Moore-Penrose可逆。同时给出了这2个算子Drazin逆及Moore-Penrose逆的相互关系的刻画。