Abstract:The lunar probe requires accurate information on position and velocity when it runs on its close phase of orbit. Dynamical estimation with GPS can provide the accuracy needed. This paper presents a description of the conditions about choosing the GPS satellites and the numbers of the available GPS satellites on close phase of orbit, the solutions of dynamical method with GPS, and the influences with different sampling intervals and force models. The results show that the dynamical method with GPS can meet the precision requirement with reduced force models and 5s sampling interval.

Abstract:The simulation of satellite orbit magnetic field produced by two pairs of Helmholtz coils is studied. Firstly, the balance of the magnetic field is analyzed. Then the effect of the magnetic field which is caused by the deviation of a coil installation and shape is analyzed. And then how to simulate geomagnetic field is put forth. finally the simulate results and conclusions are given.

Abstract:Kalman filtering is affected by the gross error that is inevitable in the observation of satellite. First robust kalman filtering is derived and its robustness is analyzed, then the observations of Lageos is processed. It verifies that robust kalman filtering has the capability to resist the gross error.

Abstract:On the basis of application of GPS carrier phase measurements to determinate the carrier's attitude, focusing on its key technical problem—fast determination of carrier phase ambiguity,a method which makes full use of geometric constraints among GPS satellites and baseline to compress search space in order to acquire the correct double differential ambiguity quickly has been developed. A simulation experiment using the rude statistics received by ADUⅡ attitude determination receiver shows that it is a practical ambiguity resolution.

Abstract:A great number of guidance problems can be considered the problems of generalized two-point boundary-value in the field of aerospace. The paper discusses the methods to solve these problems with the help of neural network. The static two-point boundary-Value problems, such as offline guidance, are discussed in the paper. Based on the discussion, the dynamic two-point boundary-value problems, such as online guidance, are analyzed, and an effective method to solve them is presented.

Abstract:Damage rules, target structrue and damage trees are proposed first. Finite elements are utilized to partition the shape of target. A vulnerability model of missile with fragmentation warhead damaging the target is built. With the validity of the simulation algorithm, the vulnerability model of the missile-launching vehicle is researched into and its result is given. From the result of the simulation, the damaging course of the missile attaching the targets on the ground can be depicted.

Abstract:Based on the theory of reaction fluid dynamic, numerical simulate about the process that shock waves induce the combustible gas deflagrating in one-dimensional system with the chemical model of nine equation is successfully accomplished. The generation mechanism of the induced process and an important effect of shock waves extinguishing the forest fire are clearly interpreted by the density variety of CO and the variety of pressure and temperature in the field.

Abstract:In order to apply Coherent Anti-stokes Raman Spectroscopy(CARS)to combustion diagnosis, this paper studied correlation between theoretical CARS and temperature, correlation between theoretical CARS and concentration and correlation between theoretical CARS and pressure. Also, LPG/air flame temperature was measured with N₂ CARS

Abstract:The granule flow equations are deduced from the generalized BGK model. The generalized BGK equation is treated with the Chapman-Enskog method that is used in the classic molecular kinetics. The equations are easily generalized since the method is simple and the quantities in them have concise physical meaning.

Abstract:When a planar shock wave is sweeping a density layer, the deformation of the density interface and the wave configurations can occur. Numerical simulations about this process for high density layer is proposed. The result based on TVD scheme is checked using analytical simulations, It shows that the interaction of the shock wave with the high density layer can induce the wave reflection from the wall which is either a stationary regular reflection or a stationary Mach reflection.

Abstract:The influences of three common boundary conditions at low speed entrance on stability and convergence are present by solving 2-D compressible Euler equations that have been preconditioned. The test shows that by preconditioning the boundary condition based on the Riemann invariants at low Mach numbers is reflective boundary condition while the other two are unreflective boundary conditions.

Abstract:Dugdale-Barenblatt model is extended to analyse the problem of the crack on the interface between two viscoelastoplastic materials. After the governing equations are Fourier-transformed, the problem of boundary conditions with tangential jumps trans-formed into singular integral equations by using sectional definite-integral transformation. Following solving the integral equations are the formulation of the length of the plastic zone (LPZ) ahead of the crack tip and crack-tip opening displacement (COD), and the derivation of the strain energy release rate. Results reveal that the LPZ and COD are both determined by the minimum yielding stress of the two constituent materials, and the latter also rises at a gradually declining speed as time increases.

Abstract:Model organization and description are a basic problem in decision supporting systems. At the same time, they are also the preconditions in model management. After studying the integrated modeling and design and development of CS-DSSP（Client/Server based decision supporting systems platform）, an integrative framework for model organization, called IFMO is introduced, which includes component model description, model component framework, architecture of integrative framework etc. IFMO provides a method that implements a new modeling technique in DSS.

Abstract:Considering the characteristics of conceptual design and the feature classification of virtual prototype, this paper presents a novel virtual prototype-based product model, V-desModel, and the description language, VPML, in conceptual design. It introduces virtual feature concept in the product's view models, and employs expandable 3D entity-constraint graph to describe the constraints between design objects. V-desModel and VPML language can effectively support the process of cooperative design and concurrent design, solve the insufficient information problems in constructing virtual prototype during the conceptual design of product. They provide coherent model description for cooperative design, concurrent design, and confederate simulation of multi-discipline systems.

Abstract:In the architecture design stage of super computer, it is indispensable to perform timing planning to judge the physical realizibility of architecture alternative and performance metrics as early as possible. This paper presents a performance-driven timing-planning method. A timing performance model which is suitable to describe component performance is adopted, and the path delay slack is distributed according to net weight. The algorithm has advantages of high efficiency and rational delay distribution.

Abstract:The principle of extended TDOA histogram method is discussed. An application of multistation TDOA position location based on extended TDOA histogram method is illustrated. A comparison between extended TDOA histogram method and traditional TDOA position location signal processing is listed. A way to approach the real time processing is pointed out.

Abstract:A digital GPS PN code acquisition circuit based on direct IF sampling is presented. Based on the mathematics model of this circuit, the relations between searching rate, probabilities of false-alarm, probabilities of detection and input carrier-to-noise density ratio(C/N₀) are analyzed. A digital system scheme based on the acquisition circuit is proposed. According to the result of the analysis the digital acquisition circuit can be adopted for improving acquiring performance and system reliability.

Abstract:This paper presents a symbol synchronization method in software radio system, which should be implemented with software on the view of software/hardware co-design theory. The new method is also based on signal interpolation theory in which the conventional polynomial filter is replaced by an optimal filter. To solve the high BER problem when transfer delay is half the symbol period, an energy-check algorithm is further introduced taking the advantage of a large number data nemory.

Abstract:A method for fast detection of texture faults in texture images is presented. Texture discrimination is implemented based on the K-S distance of the representative block of each site in the image and the texture prototype. The basic properties of the K-S distance are studied here. A texture prototype estimation method and a hierarchical efficient searching method are presented. The experimental results for both natural and synthetical images have proved the efficiency of this algorithm.

Abstract:MP3 music format which uses MPEG audio LayerⅢ compressing algorithm is popular for its high compression rate and CD-like quality. The fixed point programming of the MPEG audio LayerⅢ decoding algorithm is implemented after being simulated with C++ language, which can be used to realize the real time decoding of MPEG audio LayerⅢ based on digital signal processor.

Abstract:The finite-difference time-domain method (FDTD) is used to simulate propagation of Gaussian pulse in waveguide. According to the dispersive characteristics of waveguide, a new modulate pulse is presented for excitation source of waveguide, and the formulations of pulse width T and modulate frequency are also given. Applications of the technique are presented, and the numerical results are compared with experimental results, and the comparison shows excellent agreement over a wide frequency band.

Abstract:A 2-1/2D full electromagnetic particle-in-cell code ABLE2D is presented. The physical model and computational technology in cylindrical mesh, with r-and z-coordinate dependence, has been introduced in detail. Applying object-oriented technology to analyses the physical objects and their physical property, we have reasonably build up object models of solution space and successfully realized the computational function of Plasma simulation system.

Abstract:In this paper,the problem of nonresonant bifurcation in nonlinerar oscillation system is studied,the response equation of bifurcation of the system is derived and the stability of Limit cycle is analyzed respectively.

Abstract:To output a large magnetic torque with low batteries voltage for electric vehicle drive system, two modes of over modulation for space vector PWM are presented. Experimental results show that they are fit for electric vehicle drives with increasing magnetic torque and output voltage.

Abstract:Local linear prediction is often applied to predict nonlinear time series, which uses the ordinary least square(LS) method to estimate the parameters in the approximated linear models. If there exists noise in the process, the computational stability of the method is rather poor. This paper presents an improved method that uses the orthogonal least square (OLS) algorithm to estimate both the structure and the parameters in the linear models from linearizing locally the whole nonlinear space. The proposed method can solve the ill-posed numerical problem to some extent and increase the stability of prediction algorithm.

Abstract:During the recent decade, the active noise control technology has becoming a hotspot of the noise controlling field, which is the extend and intercross of several subjects. Its ability of eliminating low frequency noise, light weight and compactness have been fully understood Firstly this paper simply introduce its theory. Then the actuality and nodus of its theory research, implementation technique and product at home and abroad are elaborated in full. Finally some problem of its practicability are analyzed further and several major developing directions are presented.