Abstract:During the research on Solid Ducted Rocket (SDR), it is an important link for the design and experiment of SDR that a suitable mathematical model is built to simulate its internal working process. The turbulent reacting model presented in this paper was based on a 3 D ducted rocket. Then the numerical simulation of the model was given and some conclusions were obtained. The conclusions are useful for the design and experiment of the ducted rocket.

Abstract:Optimization and dynamic reliability analysis of the structural system are combined. A methodology of optimum design based total failure probability of the structural system with multi-degree freedom under stationary stochastic excitation is presented when minimum weight of the structure determined by design parameters is the objective function. According to the spectrum analysis theory, the statistical property of the response of structural system under stationary random excitation is analyzed. At the same time, Possion process model based on first passage failure is used to calculate the reliability of the structure, and the optimum design parameters are finally obtained through Hestenes-Powell (HP) method. The result of evaluated examples demonstrates that the method presented in this paper is effective.

Abstract:Based on the constitutive relationship of viscoelastic material using the Burgers model and the corresponding viscoelastic finite element method, the finite computational models are established to value the effects of solid rocket motor material parameters on the structure integrity. They include the three-dimension model and the plane strain model. In the case of thermal loading, the three dimension model is necessary, but the plane strain model is accurate enough in the case of internal pressure. Then, the effects of solid rocket motor material parameters on its structure integrity are respectively compared and analyzed under internal pressure and thermal loading by the use of MSC/NASTRAN software system. Under thermal loading, the main factors affecting the motor structure integrity are the propellant Poission's ratio and thermal expansion coefficient. Under the internal pressure, the main factors are the motor liner Poission's ratio, propellant initial elastic modulus and Poission's ratio. These conclusions would be useful for to the design of solid rocket motors.

Abstract:The traditional calibration method is always imprecise, unstable and computed costly because of the nonlinear effect lead by lens distortion. A new camera calibration method of varying effective focal length by neural network model is presented. Both calibration result and 3D measurement result show that the new method achieves more precision and stable result than classical method does.

Abstract:The technology of the real-time communication between the Galaxy Simulation Workstation (GSW) and the shared-memory real-time network is first researched. Then the application program interface (API) of the real-time communication between them is introduced. And an example of real-time network communication, which is implemented in YHSIM simulation program, is described. Finally, the experimental result is given, which proves this technology can be effectively used for semi-physical simulation of large scale complex systems.

Abstract:The evaluation technology of the Attack Effect of computer networks is an important and challenging subject of security evaluation in information systems. Nowadays, corresponding theory is not mature and correlative research reports are few. In this paper several currently primary evaluation techniques of information security are concisely analyzed. Then three evaluation models, i.e., the evaluation technique based on network information entropy, the security evaluation framework based on analytical hierarchy and the synthetical evaluation technique based on analytical indexes, are presented in order to conveniently measure and estimate the attack effect. Finally, some problems which must be paid attention to in practice are pointed out.

Abstract:The method of implementing the network survivability design using the diversity dynamic drifting techniques is proposed here. The influence of this techniques on network security and survivability is analyzed. And an architecture skeleton of this technique is then presented. It is pointed out that the research has the features of prevision, completeness and realit

Abstract:Anti-line target terminal-sensitive cluster warhead is a new kind of bomb.It has good shooting efficiency.Based on the analysis of the scattering and flying properties of the terminal-sensitive cluster warheads，an approximate simulation method for the end points is introduced. Analysis is simple and the result is acceptable. It provides a good referential tool for the analysis of terminal correction cluster warhead system's shooting efficiency.

Abstract:This paper introduces the concept of the critical points stability of the mapping theory into the singularity analysis of parallel manipulator and proposes the concept of stable singularity and unstable singularity. Some low degree-of-freedom parallel manipulators are researched into and the results verify that the classification of singularities according to their stability is reasonable. The proposed method can provide theoretic foundation for the structure design and control of parallel manipulators.

Abstract:We propose a kind of dynamic reliability growth model. Firstly, by using the middle rank in statistical field and the data gathered in the practical tests, we can find the failure rate of different growth periods. And this technique can solve the small sample problems. At the same time, this technique embodies the dynamic modeling thoughts, so it can well describe the practical condition of the running system. Secondly, this model inherits the merits that is simple, direct, easy to value the references of traditional Duane model, on the other hand, it can be used in the multi-period or multi-environmental tests in which traditional Duane model can not be applied. Thus, this model can be widely used in engineering. Finally we give a simulating example in order to demonstrate how to use this model and test the correctness of the model.

Abstract:Aiming at the time-consuming problem of clusters testing in boundary scan testing of circuit boards, an application scheme of clusters testing-the overlapped application scheme is proposed based on “parallel testing”. Theoretical analysis and experiments show that this scheme is the best testing application scheme and can reduce the clusters testing time greatly.

Abstract:Methods of software design based on COM are used to modularize the CNC systems and the crux is communication. “Event” and “Event slot ” are used to realize the communication between different client component modules and between client and sever. It provides a new software method of the solution to the communication problem of open CNC system.

Abstract:RSA cryptosystem is the best one of the public key cryptosystems, and its enciphering or deciphering speed depends on a powering algorithm. This paper proposes a powering algorithm based on disparting blocks. By analyzing its complexity and comparing the complexity with other powering algorithms, it is proved that this is the fastest powering algorithm in Z/nZ.

Abstract:Extended Kalman Filter(EKF) and converted measurement Kalman Filter(CMKF) have been widely used in radar target tracking. However ,when cross-range measurement errors of target position are serious, the performance of conventional EKF and CMKF degrades considerably. In this article debiased converted measurement Kalman Filter(DCMKF) is inferred with velocity measurement. Simulation results show that DCMKF has a higher accuracy than EKF and CMKF.

Abstract:Back-projection(BP)algorithm is a popular imaging algorithm for impulse SAR. The relation between BP's azimuth resolution and azimuth angle as well as signal's center frequency is discovered when the radar's transmitted signal is one kind of impulse signal based on the characteristic of the impulse SAR imaging.The simulation results prove the estimation formula's validity.

Abstract:This paper describes the general concept of the channel capacity, gives a detailed analysis of the channel capacity of the waveform channel, continuous channel and the discrete input continuous output memoryless channel, then derives their general formulae of the channel capacity respectively. Combined with several known m-ary multidimensional modulation techniques and their constellation analysis, Monte-Carlo simulation and the numerical integral simulation are given for their channel capacity. Finally the coding gain due to the signal sets expansion is analyzed.

Abstract:By employing the new measurement information—rate of phase difference measured by two-element antenna array (interferometer), a passive location systems can find the position of enemy emitters more quickly with higher precision. The accuracy of phase difference is critical to this passive location system. A digital method for measuring it is presented. Spectral analysis on the signals in the measuring system is given, and the signal to noise rate is calculated, then the theoretical accuracy of phase difference is derived. The accuracy is also verified by the simulation results given in the paper.

Abstract:The main circuit of three-phase bridge PWM rectifier is introduced, and the operational principle by which it realizes unit input power factor and does not pour harmonics into power network is analyzed. On the base of those, a new system configuration for high power three-phase PWM rectifier, whose main circuit consists of parallel two modules, is proposed, and its control approach and corresponding control system as well as the driving and protective circuit are discussed. Finally, the experiment for the prototype of capacity 100kW is investigated. The results show the good performance of the three-phase high power PWM rectifier presented.

Abstract:The computation of Green's function in spatial domain is the key difficulty in solving multilayer structure. According to the nonuniqueness of inverse problem, a novel method based on discrete complex image method(DCIM)—fixed real image method(FRIM) is put forward.According to this method, we use fixed images at real instead of complex locations to approximate the spectral Green's function, the images real locations are selected according to the classic image theory, and the complex amplitudes can be obtained using simple point match method. This method is simpler and faster than the complex image method for avoiding the fitting procedure of Prony or GPOF. A group of computation results are given and validated by DCIM.

Abstract:The bigger the undulation of gray-level in a neighborhood region, the bigger the sum square of the ratio of each gray-level to the total gray-level in the neighborhood is. Thus a method of detecting smallmoving targets based on the distribution of gray-level in the neighborhood is described. Considering the complex background, especially which involves a lot of edges and high-frequency motionless points, we brought forward improved methods for detecting possible targets.Finally, the neighborhood judging method is presented to pick out the moving targets. Simulation result indicates that this approach can reduce the number of possible targets and detect small moving IR targets in complex natural background with high efficiency and veracity. Furthermore, it can be used in real-time and multi-targets detection.

Abstract:A tank group may meet with the enemy's tank group in the tank warfare. Each tank will fire at the tank which greatly threatens itself, but the result may not be optimal as a whole. A method of the target selection in the tank warfare is proposed to minimize the enemy's whole threat. The result of the model may improve the combat effectiveness of the tank.

Abstract:Option contracts are probably stopped before expire dates and important events may cause jump of underlying assets price. The paper assumes that the two kinds of risks,caused by stochastic stopping and the jump of price, are nonsystematic. By means of no arbitrage capital asset pricing and Feynman-kac formula, it first studies stochastic lives exchange options pricing with the underlying assets obeying continuous diffusion processes and the underlying assets obeying jump-diffusion processes, and obtains corresponding pricing formulas. And then, it studies the stochastic life option pricing with the underlying asset obeying jump-diffusion process and interest rate being stochastic, and oblains corresponding pricing formula.

Abstract:The method of cell, based upon the effective stiffness theory, can be applied to construct the constitutive equations of materials with periodical structure, especially laminated materials, and simulate the propagation of stress wave. In this paper, two kinds of initial conditions are listed for the simulation of dynamic response of nonlinear elastic materials according to this method, and the oscillations of stress wave in laminated materials are researched.

Abstract:Based on the modified effective Hamiltonian for the system which the degenerate V-type three-level atom interacts with coherent state cavity field under far-off resonant condition, the wave function of the system is derived by means of matrix forms. A feasible scheme is presented for the teleportation of an unknown atomic state via far-off resonant interaction of a degenerate V-type three-level atom with coherent state cavity field.