Abstract:In this paper，the inf1uence of MEPI is studied. The OC-function of testing statistical hypothesis and the numbers of launchs of reentry vehic1es are given. It shows that when one tries to compensate the risk of the dispersion assessment caused by MEPI，the numbers of launchs wil1 be increased. As for statistical estimation， the existence of MEPI wi11 reduce the confidence probability when confidence interval is maintained.

Abstract:Based on fandamental equations for two-phase f1ow in combustion chambers of solid propellant rocket motors，this paper derives calculation equations taking into accoant erosive burning and two-phase f1ow. A numerical solution to these equations is discussed in detail; the effect of variabi1ity of cross-sectional area of channel along the 1ength， which is caused by erosive burning，and two-phase f1ow on pressure-time curves and f1ow field in chambers is analysed. It is useful for predicting pressure-time curves accurately and calculating f1ow field in chambers thoretically.

Abstract:The radiative cooling thrust chamber loses a considerably large quantity of heat due to high temperature of the outside wall，causing specific impulse loss of the engine. Up to now，no calculating methods for this problem have been found yet. In this paper， formulae of the specific impulse loss for the inside and outside processes are estab1ished. These formulae are a part of formulae for the design calculation and the performance assessment.

Abstract:A complex mode synthesis method for the consideration of the effect of adjoint force is preserted here. First，the expression of component displacement vectors is derived by mode accelaration method. Then，the equations of motion in generalized coordinates are derived by virtual work principle. Thus，the number of independent coordinates is greatly decreased and only a few lower complex modes of component are required in synthesis.

Abstract:There are many methods to match the shock spectrum in the laboratory，one of which is optimization method. This paper modifies. Rountree's Model. The shock spectrum forms which can be matched are more than Rountree's ordinary method. In order to assure the app1icabi1ity of this modification，a test is made on the 300kg electrodynamic shaker which is control1ed by a TRS-80 micro-computer， and the accuracy is satisfactory.

Abstract:This paper presents, a new method for vibration modal parameter identification using experimental technique of multiple-point random exicitation. The method is defined as the combined frequency response function method (CFRFM) in this paper. Theoretical model and computational formulae are developed and examined by actual engineering examples. The method can be efficiently used to experimental modal-analysis of large and complex structures. It has the advantages for simplicity, convenience and high-accuracy. The method can analytically separate c1osely-spaced modes in a certain extent.

Abstract:After the production of a typical vessel used to store test，many cracks in the welding seam have been observed. According to probabilistic fracture mechanics，the reliability of the pressure vessel is given by R=1-∫^+∞_-∞?(a)da∫^a₀Φ(a_c)da_c Our analysis of data from 165 samples has shown that the fracture toughness K_cobeys the normal distribution and the second type of exponential distribution for the crack sizes is better applicable to fit the data of crack sizes in a welding seam. The reliability is calculated by using Monte Carlo method.

Abstract:This paper studies the application of the method of quadratic programming. By means of optimum design of integrally stiffened waffle shell and solution of dual prob1em of geometric programming using the method of quadratic programming，we have proposed the fol1owing methods: the variables substitution，the gradient travel mode for an improvement on initia1 expansion point，the restrieted step method and the modified Gauss elimination. Some simple and efficient methods are given for the utilization of the method for quadratic programming. The results obtained here Show that those approaches a1so have a good effect on convergence hastening and accuracy raising.

Abstract:In this paper，an overall analysis of advantages and disadvantages is given for three kind of composite revolving shell elements，namely the cone element，considering the continuity of the normal rotation and the isoparametric element with three nodes. Their compatibility condition and completness condition are discussed. The rate and accuracy of convergence and the computational time are compared in numerical examples， and the range of their use are given also.

Abstract:In this paper of adaptive array superresolution techniques，three methods of directional spectral estimation are presented: the Maximum-likelihood (ML) method，the Maximum-entropy (ME) method and the Eigenvector (EV) method. The spatial lattice filter algorithm is discussed，and the performances of the three methods are compared .

Abstract:This paper proposes two kinds of soft-decision decoding algorithm of block codes-Fast Hard-decision Error Trap Decoding (FHETD) and Fast Soft-decision Error Trap Decoding (FSETD). Some theoretical analyses and simulation results to the algorithms are given.

Abstract:In order to measure the speed of a projectile accurately and rapidly，a measuring speed radar is often used to process the signals produced by the projectile nose. It is a main method for measuring speed widely used in the world. In the aspeet-of signal data processing，the domestic measuring speed radar lacks some functions and has poor reliability and low speed. So we have developed some measuring speed radars in our shooting range with microcomputer. This paper illustrates how the microcomputer is used to process the radar signals so as to measure the speed of a flying projectile rapidly and accurately.

Abstract:The symbolic representations of the pictures are the basic procedure for the computer description of the visual pictures. In this paper，the various methods of the symbolic representations of the pictures are dcicussed，such as the pixel features，the shape features，the geometric structures and the syntactic relations etc. these features are divided into two groups: attribute and non-attribute，accordingly there are two types of the distances to measure the resemblauce of objects or subpictures also: the attribute distance and non-attrilute distance. The semantic net and relaxation laleling methods are discussed too. They resemble the human visual processings more.

Abstract:From the train marshalling problem， mathematicians autline a mathematics model. cal1ed as "the digit-grouped partition of sequence"，and give some results. In this paper. we get a recursion formula，by which the number of digit of a sequence is reduced step by step，and obtain a dynamic algorithm solving a number of the optimal digit-grouped partition of sequence.

Abstract:On the basis of the method of action-angle variables the conditions of closed orbits under the action of general power-type gravitation potential are discussed on this paper. By method it is unnecessary to assume that the initial orbit is near to a circular orbit. Form of gravitation potential can be extented to the inverse proportional force field and other power force field. The discrimination formula of the closed orbits is given. Finally，if the central force contains an r^-2 term and an r^-3 term，as provided by relativistic corrections，then the orbit is closed and is in the form of a precessing ellipse. Finally the precessing angular velocity of the ellipse is calculated.