Abstract:Delaminations may greatly reduce the buckling load of the laminated structure. Cylinder including arbitrary delaminations in longitudinal and thickness and spaning the entire circumference was divided into multiple sublaminates shell whose longitude displacements were simulated with linear function of the thickness coordinate. The variational principle was applied to obtain the governing equations and boundary conditions. The state-space scheme was used to solve the problem. By comparing with classical theory, the usable range of each theory was pointed out. Three difference buckling modes of delaminated shell were considered. The influence of boundary condition, length and depth of delamination on buckling load was analyzed. Finally, the buckling analysis of delaminlated orthotropic shell was given.

Abstract:In the plane stress problem, the exact solution of stress in pure bending of beam acted by linear distributed external forces is obtained. The approximate solution of displacement is obtained by Euler method. When Poisson's ratio is zero, the exact solution of displacement is obtained.

Abstract:Using alternating direction implicit NND scheme, the TLNS equations were solved under the assumption of perfect gas, and the space grids of complex wing-shape were generated by solving parabolic partial differential equations. Finally, the numerical simulation results of liftbody-type were shown under the conditions: M_∞=8.0,α=20°.

Abstract:Interaction of plug nozzle jets with supersonic external flow was simulated numerically based on 3-D TLA NS equations with ENO scheme, then the structure of the flow field was analyzed. Calculations were performed under two-component model in which the external flow was air and the jet was fuel gas. Turbulence was taken into account with a k-ε turbulence model. The results agreed well with the reference.

Abstract:An new uncoupled method was introduced to simulate numerically nonequilibrium flow which had the stiffness problem. The flow phenomenon of H₂/O₂ combustion induced by shock was simulated with the method, based on N-S equations and NND2M scheme. The results indicated that the method was simple and efficient in the application to multi-component and multi-reaction flow.

Abstract:A kind of igniter has been designed for minute solid rocket motor. Many tests have been done to determine the ignition characteristics of minute solid rocket motor. A concept of initial ignition pressure has been introduced the principal principle which effected ignition delay time scatter has been found and determined the ignition scheme satisfying the demand for ignition performance of minute solid rocket motor determined.

Abstract:The crystal window of high-power laser can not work in gear because of the heat caused by absorption of high-power beam. The supersonic free-vortex segment is usually employed to seal low-pressure laser-cavity. In this article the procedures are described for determining free-vortex segment properties. Characteristics method is used to design nozzle which produces free-vortex segment.

Abstract:Two problems are dealt with in this paper: One is how to get the distance information in passive missile guidance with bearing-only measurements; the other is the target adaptive guidance. The adaptation includes the change of the guidance aim point from the point tracked by the seeker to a vulnerable point of the target. Simulation results indicate that the algorithm is efficient.

Abstract:Ni-P-SiC complex chemical platings were investigated by chemical co-deposition method. The composition and surface of the plate were analysized by XSP and SEM. The hardness and anti-corrosive abilities were also studied at the same time. The results showed that the plates' hardness increased with the increase of SiC concentration in the plating solutions. SiC concentration of plates were greatly influenced by plating solution concentration and its pH value. SiC concentration of plates got its top value, 16.81%, while SiC concentration in the plating solution was 7.5g/L and plating solution' pH value was 4. 7. However, the plates' surface became dim and rough, and the plates' anti-corrosive abilities decreased.

Abstract:The motion error of SAR will bring about phase error and affect the result of the pulse compression. In this paper, the motion error of ground rail UWB-SAR is analyzed, and the effect on azimuth pulse compression is investigated. A scheme of motion compensation is put forward in the end.

Abstract:Compared with usual SAR, the computational load of UWB-SAR system for imaging is larger, and the realization of real-time processing is more difficult. According to applying sub-aperture process to the BP algorithm, a practical real-time imaging algorithm (Local BP algorithm) is presented. For a SAR image area with N pixels each side, LBP algorithm can reduce the required operations, and it has a good parallel and pipelined architecture.

Abstract:Based on the optimal decoding algorithm and basic principle of iterative decoding for turbo code, the stop criterion for the iterative decoding is deduced under the condition of cross-entropy minimization and iteration convergence. A simplified algorithm that reduces calculation complexity and store space comparison to the original criterion is worked out. Finally, it is proved that the iterative stop criterion and its simplified algorithm are both valid by simulation.

Abstract:This paper introduces a new blind adaptive multiuser detection algorithm based on MMSE criterion, and its performance is analyzed. The algorithm has low complexity, and the method proposed here has better performance than MOE detector.

Abstract:The design method of a multi-mode modulation module based on PCI bus is presented and realized. Its foundation on which many types of middle-frequency modulated signal are produced is the theory of orthogonal modulation and digital-up-converting. Another abstractive feature is that it connects the base-band processing unit with PCI bus so that a flexible and powerful multi-mode modulator can be made by combined this module with the general computer or commercial DSP board.

Abstract:A novel method of microstrip line-fed excitation source is presented in this paper to analyze microstrip problems by the finite-difference time-domain method (FDTD). Unlike previous excitation treatment, which can only be used to calculate Gaussian pulse incident wave, this method can be used to calculate Gaussian pulse incident wave and harmonica incident wave. It is not necessary to switch the source wall to absorbing boundary condition in the iterative process. Because of field zone division, reflected fields naturally separated from total fields.

Abstract:An optimal overlapping boundaries model is presented, aiming at the explicit difference schemes on distributed memory parallel computing, in accordance with the architecture of distributed memory multiprocessors. This model has been successfully utilized in the optimization of distributed parallel computing of the third generation ocean general circulation model of the Chinese Academy of Science.

Abstract:Based on the features of ORDM(Object-Relational Data Model) and the query language, a new reference based on join algorithm Sort-Loop is represented. Reference is not only one of the important modeling mechanism, but also beneficial to the design and implementation of joining algorithms, such as Hash-Loops. By overcoming the shortcomings of the Hash-Loops in the data access manner and the use of the main memory, Sort-Loop is of high performance. This is validated by the analysis in the paper.

Abstract:This paper presents the nonlinear analysis and processing of signals based on chaos aspects. Chaotic invariants are described, including Lyapunov exponents and fractal dimensions. The problems of applying Takens' Embedding Theorem to phase space reconstruction are discussed, including those of embedding dimension and time delay. Then RBF neural network used in nonlinear processing of chaotic signals is presented.

Abstract:The finishing of turbine blisks, a critical technology determining the final geometric accuracy of blisks, can be implemented efficiently with the electrical discharge machining ( EDM). Upon the basis of the design of the electrode for blisk EDM finishing, the searching of an interference-free path for feeding an electrode through twist channels of a rimed blisk is carried out, in which the kernel problem is the determination of the electrode kinematic constraints. An implementation of the path-searching algorithm is illustrated with an example at the end of the paper.

Abstract:This paper is aimed at analyzing the identification precision of the finite impulse response (FIR) function models of discrete-time control systems under the pseudo-random invert-repeated m-sequences stimulation1 An explicit formula of the correlation identification precision is given in the face of colored noises. Two simulation examples are cited to support the analyses.

Abstract:A parameter estimation method is proposed for Dynamic Tuned Gyro (DTG) fault diagnosis based on kinetics model of rotor. Fault simulation and diagnosis experiments are carried out on the DTG of a strapdown inertial navigation system. The results show that the parameter estimation method is very efficient and practical, providing a new approach and idea for the gyro fault diagonsis.

Abstract:There are a great number of Chinese character annotation with different size in topographic map. Extracting the Chinese character annotation in scanned topographic map image is the key condition and foundation. The advantage and shortcoming of interactive extracting method and automatic extracting method is analyzed briefly. An intelligent extracting method based on the active knowledge base is presented and realized, combining the advantages of both. The algorithm is efficient.

Abstract:The MFTA software provides a computer-aided tool for the reliability engineers to analyze multi-state system. Designed on the platform of Windows 95, it has friendly interface. The software used TreeView component to input the logic tree, used StringGrid component to input the judgment table directly. What is more, it can fulfil the conversion of logic models from typical structure function to judgment table automatically. Based on Standard Template Library of C+ + Builder, the library of cube class, upon which the Cube Theory-based MFTA algorithms and analysis methods are implemented, has been developed. The software can be used successfully in the multi-state system reliability analysis.

Abstract:Shot clustering is an important aspect of video content analysis. The basic task of shot clustering is to classify shots based on their low-level features. This paper describes a novel shot-clustering technique. Beginning with an initial classification of the shot set, our algorithm proceeds with merging and splitting iteration alternatively to reduce the errors in the initial results. The main advantage of this algorithm is that it does not need any experiential parameters or thresholds, nor does it need any manual interaction. In this way, our algorithm overcomes shortcomings of tradi tional clustering algorithm and works well in practical systems.

Abstract:Based on the generalized bottom boundary condition proposed by Cheng, Cheng derived an analytical solution with compli-cated form and we need to solve two transcend equations in order to get the analytical solution. In this paper, we analyse the difficulties in the analytical solution calculation.We reduce the searching regions for finding roots of the transcend equations easily. On the other hand, according to the numerical results,we found that the constructed difference schemes with scheme parameter 0.48≤Θ≤1 are stable and identify with the analytical solution.

Abstract:The Free-Lagrangian Method Based on Taylor’s Expansion is developed. A one-dimensional hydrodynamic code is written according to this method. Both examples of the shock tube and impact of flyer on the target are simulated by this code. The results are in good accordance with that obtained by traditional Lagrangian difference code.