PARALLEL ALGORITHMS FOR A LARGE SPARSE SYSTEM OF LINEAR EQUATIONS

ABS algorithms new agorithm is introduced with the discussions of the sparse structuere of the projection matrixes and the reorder methods of equations. To apply ABS algorithm on qarallel computer, the parallel ABSalgorithu is also discussed with numerical examples and the time need for the computation.     

A MIMD PARALLEL ALGORITHM TO SOLVE TRIDIAGONAL TOEPLITZ LINEAR EQUATIONS

The rank one updating formula and the parallel eliminating algorithm for linear recurrence systems ane combined fo form a MTMD parallel algorithm fo solve tridiagonal Toeplitz Cinear equations. This algorithm has a simple strictire and requires onlty a few storages as well as in-terprocessor communications. There is no special demand on the number of processors in the parallel system. The speedup can come dose to p12 comparing with the LU decomposition method (p is the number of processors). It is worth pointing out that it is proposed algcmthn that considels and organizes the parallel arithmetic in the first order linear ricurrence systems with constant coefficients.     

TWO MIMD PARALLEL ALGOITHMS FOR SOLVING ALL PAIRS SHORTEST PATHS

Based on multiprocessor Mpscu, two parallel algorithms are proposed to solve the shortest path problems in N vertex graph within time O(N3/k)with K processors.     

THE REANALYSIS THEORY OF COUHLED METHOD OF FINITE ELEMENT AND BOUNDARY ELEMENT METHOD WITH VARIATION OF BOUNDARY

The coupled element of finite element and boundary element theory has been used to carry out the reanalysis of structures with geomeotric variation based on the varitional principle. It will not only reduce the amount of analyser' work,save the memory of computer,but also enhance the accuracy of reanalysis. So it will effectively make the reanalysis of large structures easy.     

A FAST ALGORITHM FOR DIGITAL SIMULATTON OF HVDC SYSTEMS

After considering the features of the differential equations which have described the dynamic behaviours of HVDC systems, a fast algori -thm is presented for these equations. Compared with the fourth Runge-Kutta Method,this method has less amount of calculation with the same precision, numerical stability and other properties. Therefore, the use of the method has greatly increased the speed of the digital simulation of HVDC systems.In this paper an example of calculation is given, and the results obtained hv using this example are compared with the results obtained by calculating with the fourth Runge-Kutta Method. The speed of simulation by using this method is about 1.8 timss as fast as that by using the fourth Runge-Kutta Method.     

AN IMPROVED MIXED FINITE ELEMENT METHOD OF ANALYZING THREE-DIMENSIONAL ELASTIC CONTACT PROBLEMS

This paper presents an improved mixed finite element method of analyzing elastic contact problems, in which a new numerical algorithm is developed to calculate the flexibility matrix of the contact region. With this method the contact problem of two teeth-engaging is initially solved as a three-dimensional elastic finite element analgsis, In comparison with mixed fimte element method, the improved mixed finite element method is much more efficiency in solving contact problems.     

ANALYSIS AND PROGRAM FOR CHUNK AND STIFFENED SHELL STRUCTURES BY FINITE ELEMENT METHOD

The improved isoparametric shell element and the biased Isoparametric beam element are applied to the composite structures which consist of cubic chunks and stiffened shells. A flexible and practical method is found for this type of composite structure. The example shows that the theory and program are efficient.     

A RELIABILITY PROCESSING ALGORITHM SUITABLE FOR STOCHASTIC AND SUDDENLY VARYING DATA

In regard to stochastic and suddenly varying data,a new kind of data processor algorithm based on adaptive prediction is presented.The algorithm describes the changing pattern of measured variables by means of time series models with slowly time-varying parameters,forms the criterion by use of the adaptive and its 95% belief limit,and processes the measured data so as to reject or restrain outliers mixed in them.The simulation example indicates that the algorithm surmounts difficulties which most current algorithms encounter when processing stochastic and suddenly varying data and that it is of obvious effects.     

求解粮食调运问题的两阶段优化算法

粮食调运优化问题过去已有研究,但是当问题较为复杂时,传统算法就要花费大量时间而且准确性也难以保证.针对这一缺陷,本文对已有的粮食调运模型进行改进,并基于该改进模型提出了一个解决粮食调运优化问题的两阶段求解方法,在第一阶段,由图搜索算法产生所有可行的运输路线,并根据约束条件对搜索树进行剪枝;在第二阶段,采用蚁群算法从第一阶段产生的可行路线集合中选取最佳路线,使总的运输成本最低.经过实例测试,该算法在粮食调运过程中具有较好的效果.     

A SELF-TUNING CONTROL FOR A PARALLEL AC/DC POWER SYSTEM

Based on a non-linear system model, an adaptive control methodology is presented for a parallel AC/DC power system by means of on-line recursive parameter identifications. Taking the advantage of rapid power regulatiing ability of the DC power system and combining with the generalized minimum variance self-tuning control principles, the dynamic qualities of the controlled system has been greatly improved. Using SISO form makes the control system very simple to implement. Through the design, simulation and analysis of the self-tuning control system for a practical example, it shows that the self-tuning control strategy is very promising for AC/DC power systems.     

DIGITAL SIMULATION OF HIGH VOLTAGE AC/DC PARALLEL SYSTEMS

The method of companion model is applied to the digital simulation of high voltage hybrid AC/DC systems for the first trme in this thesis.The mathematical model of the digital simulation of hybrid AC/DC systems is represented. This method can model the normal states, faults and games of faults of any hybrid AC/DC systems. The method has a series of advantages : saving the computation and the amounts of memory, high precision and fast calculation and it can be used with convenience. The simulation results of a hybrid AC/DC system arc in consistent with that of theoretical analysis. It shows that the mathematical model, the simulation method and the program in this thesis are correct.     

AUTOMATIC MESH GENERATION SCHEME IN FINITE ELEMENT CONTACT ANALYSIS OF MESHING GEARS

In this Paper, a new automatic mesh generation scheme is present, which combine the teeth contact analysis with the modelling of finite element cotact analysis. This procedure is different from the ordinary auto - mesh - generation scheme. The presentation of this new procedure makes it possible to analyze the elastic contact problem of meshing gears by a finite element method.     

THE APPLICATION OF FINITE - ELEMENT METHODS FOR THE ANALYSIS OF GALLBLADDER BILE FLOW IN VIVO

The transient flow fields of gallgladder bile in vivo are calculated by finite element methods. Computer tomograph, ultrasound B and contrast radiography are applied to determine the moving boundary conditions, The penalty formulation and moving triangle elements have been successfully adopted and be flow fields for axisymmetric Newtonian bile flow have been obtained. The results show that there exists obvions reverse flow at the cross section (Perpendicular to Center axis) and thus forms axisymmetric vartexes inside a contracting gallbladder in vivo,Which well agree with the previous prediction.     

A FINITE ELEMENT RESEARCH ON.A LINKAGE OF A COMPOSITE STRUCTURE OF SHELLS AND PLATES

In this paper,the penalty element stiffness matrix of linkage of plates and shells is deduced accrding to the principle of the penalty elementmethod.This stiffness matrix can be also used for a linkage between shells andsolids.It is of some practical value in the finite element calculations of engineeringstructure.     

A RELIABILTY CAPACITY OPTIMIZATION ALGORITHM FOR STOCHASTIC FLOW NETWORKS

A model and a heuristic algorithm for reliabilty op timi zation in generalized stochastic flow networks are proposed in this paper. The stochastic characteristic of the demands at terminal nodes is considered in the model. The algorithm proposed is powerful and can be applied to optimal planning of transmission capacity for large scale stochastic flow networks, because it can facilitate a fast location of optimal capacity expansion from the information obtained by the last iteration by making full use of the relationships of the k-weak link set and failure events set to the paramsters in generalized stochastic flow networks     

PROBABILISTIC STABILITY EVALUATION OF AC/DC POWER SYSTEMS WITH PARALLEL MONTE CARLO METHOD

This paper presents a new method for the probabilistic stability evaluation of AC/DC power systems. The transient stability model is described and the stochastic factors having effects on the stability behaviors are analysed and modeled. A theorem governing the probabilistic relations among the occurences of different types of disturbances is derived. A method of parallel computation is oresented, which is based on Monte Carlo simulation. An illustrative example is also given to show the application of the concepts and method presented in this paper.     

A BOUNDARY ELEMENT METHOD FOR SOLVING DIRICHLET PROBLEM OF THE HELMHOLTZ EQUATION IN R~2

This paper presents a boundary element method for solving Dirichlet bou-ndary value problem of the Helmholtz equation in R~2.First,the existence andthe uniqueness of an extended solution for the problem are obtained.Then,thesolution is expressed in terms of simple layer potentials,and this expression,which is suitable to the interior as well as the exterior problem,leads to aboundary integral equation of the first kind.Finally,a finite element approachis applied to solve a variational form which is equivalent to the boundaryintegral equation.     

A NEW ALGORITHM FOR REAL CIRCULAR CONVOLUTION AND THE COMPARASION WITH OTHERS

A new conolution algorithm is proposed and its real multiplication and additional requirements are N(loy2N - 1) + 2 and 3N(loy2N - 1) + 10 respectively to evaluate the real sequence circular convolution of N points. In comparasion with others, this algorithm is better in every aspect.