关键词： 超高压   远距离   双回路输电线系统   实时仿真   数学模型  

摘要： 该文对一个两边带理想电源的超高压、远距离、双回路输电线系统建立了一种适合实时仿真的频率相关参数的数学模型,并选择了合适的算法,作者应用所提出的模型和算法编制了仿真软件.软件模拟了系统在正常操作时出现的各种状态,如空载合闸、自动并网等,仿真了故障下系统保护装置反映后的各种状态的电磁过程,仿真软件在高速数字信号处理器TMS320C30构成的并行处理系统上能够实时实现.

关键词： interior-point methods   linear systems   Jordan algebras  

摘要： We discuss a possibility of the extension of a primal-dual interior-point algorithm suggested recently by Alizadeh et al. (1994). We consider optimization problems defined on the intersection of a symmetric cone and an affine subspace. The question of solvability of a linear system arising in the implementation of the primal-dual algorithm is analyzed. A nondegeneracy theory for the considered class of problems is developed. The Jordan algebra technique suggested by Faybusovich (1995) plays major role in the present paper.

关键词： .recursive algorithm   Cholesky   total area   partial pivoting   automatic variable   DPOTRF   Recursion leads   dense linear-algebra   LAPACK level   level codes   recursive codes   matrix operands   FLOPS   DGETRF   DLASWP  

摘要： We describe some modifications of the LAPACK dense linear-algebra algorithms using recursion. Recursion leads to automatic variable blocking. LAPACK's level-2 versions transform into level-3 codes by using recursion. The new recursive codes are written in FORTRAN 77, which does not support recursion as a language feature. Gaussian elimination with partial pivoting and Cholesky factorization are considered. Very clear algorithms emerge with the use of recursion. The recursive codes do exactly the same computation as the LAPACK codes, and a single recursive code replaces both the level-2 and level-3 versions of the corresponding LAPACK codes. We present an analysis of the recursive algorithm in terms of both FLOP count and storage usage. The matrix operands are more "squarish" using recursion. The total area of the submatrices used in the recursive algorithm is less than the total area used by the LAPACK level-3 right-/left-looking algorithms. We quantify the difference;we also quantify how the FLOPS are computed. Also, we show that the algorithms exhibit high performance on RISC-type processors. In fact, except for small matrices, the recursive version outperforms the level-3 LAPACK versions of DGETRF and DPOTRF on an RS/6000(TM) workstation. For the level-2 versions,the performance gain approaches a factor of 3. We also demonstrate that a change to the LAPACK DLASWP routine can improve the performance of both the recursive version and DGETRF by more than 15 percent.

ISBN: (纸本)7312009336

关键词： 组合数学   母函数   递归关系   置换群   区组设计   算法  

关键词： 船队加解驳   多目标规划   启发式算法   数学模型  

摘要： 文章对长江航线上推轮船队的加解驳问题进行了分析和过程抽象．建立了描述问题的数学规划模型．设计了一套启发式求解算法。

摘要： We present the results of investigations carried out at the Karpenko Physicomechanical institute of the Ukrainian Academy of Sciences and devoted to the development of the methods of nondestructive testing of multilayer dielectric objects with plane interfaces. These methods make it possible to determine the thicknesses of the layers, the depths and thicknesses of the interlayers, and their permittivities by analyzing the frequency dependence of the reflection coefficient of superhigh-frequency electromagnetic waves. The procedure of determination is based on the solution of direct and inverse problems of reflection from the tested objects. We describe and discuss some of these methods and algorithms.

关键词： computational methods for control   parallel algorithms   algebraic Riccati equations   matrix sign function  

摘要： Because of its suitability for parallel computation, the matrix sign function is a popular algorithm for solving the algebraic Riccati equation (ARE). The algorithm can be numerically unstable, however, even when combined with iterative refinement. This paper presents an enhanced algorithm which is shown to be backward stable under most circumstances. The method uses a combination of iterative refinement, scaling, and shifting, together with carefully chosen stopping criteria. An error analysis supports the algorithm modifications. Computational examples demonstrate the effectiveness of these techniques.

关键词： SU(2) theory   SU(3) theory   Lie algebras   vectors   LIE GROUPS   TENSORS   WAVE FUNCTIONS   CLEBSCH-GORDAN COEFFICIENTS   SU-3 GROUPS   COUPLING   ALGORITHMS   MULTIPLICITY   SU-2 GROUPS  

摘要： A recent paper gave an explicit construction for inducing shift tensors of a compact reductive Lie group from shift tensors of a suitably defined subgroup. The shift tensors were defined on model spaces of holomorphic vector-coherent-state wave functions. In this paper, we use these shift tensors to obtain an algorithm for computing Clebsch-Gordan coefficients. The approach reproduces the known analytical results for SU(2) and gives a simple algorithm for computing SU(3) coefficients. The algorithm is shown to yield analytical expressions for the multiplicity-free SU(3) couplings of type (lambda(2)0)x(lambda(1)0). (C) 1997 American Institute of Physics.