共查询到20条相似文献,搜索用时 15 毫秒
1.
L. Yu. Kolotilina 《Journal of Mathematical Sciences》1997,86(4):2803-2827
In the symmetric positive definite case, two-sided eigenvalue bounds for block Jacobi scaled matrices and upper eigenvalue
bounds for matrices preconditioned with an incomplete block factorization are derived. A quantitative characterization of
block matrix partitionings is also suggested, which can be used when analyzing various block preconditioning methods. Bibliography:
13 titles.
Translated fromZapiski Nauchnykh Seminarov POMI, Vol. 219, 1994, pp. 5–41. 相似文献
2.
Two classes of SSOR-type incomplete block factorization methods are proposed for preconditioning of linear algebraic systems
of equations with block banded matrices of complex structure. Correctness conditions are derived for these methods in application
to M-matrices and their efficiency is demonstrated by numerical experiments with linear algebraic systems obtained by discretization
of the three-dimensional Poisson equation using quadratic and cubic serendipity finite elements.
Translated from Zapiski Nauchnykh Seminarov Leningradskogo Otdeleniya Matematicheskogo Instituta im. V. A. Steklova AN SSSR,
Vol. 159, pp. 5–22, 1987. 相似文献
3.
Sanpei Kageyama 《Annals of the Institute of Statistical Mathematics》1987,39(1):661-669
Summary This paper investigates locally resistant balanced incomplete block (LRBIB) designs of degree one. A new necessary condition
for the existence of such an LRBIB design is presented. This condition yields a complete characterization of affine α-resolvable
LRBIB designs of degree one. Furthermore, regarding construction methods of LRBIB designs of degree one, it is shown that
Shah and Gujarathi's method (1977,Sankhy?, B39, 406–408) yields the same parameters as Hedayat and John's method (1974,Ann. Statist.,2, 148–158), but their block structures are different and interesting.
Partially supported by Grants 59540043 (C) and 60530014 (C). 相似文献
4.
M. N. Yakovlev 《Journal of Mathematical Sciences》2000,101(4):3365-3371
Existence theorems are proved for an incomplete set of upper and lower functions. Bibliography: 1 title.
Translated fromZapiski Nauchnykh Seminarov POMI, Vol. 248, 1998, pp. 231–241.
Translated by L. Yu. Kolotilina. 相似文献
5.
L. Yu. Kolotilina 《Journal of Mathematical Sciences》1996,79(3):1043-1047
The paper presents upper bounds for the largest eigenvalue of a block Jacobi scaled symmetric positive-definite matrix which
depend only on such parameters as the block semibandwidth of a matrix and its block size. From these bounds we also derive
upper bounds for the smallest eigenvalue of a symmetric matrix with identity diagonal blocks. Bibliography: 4 titles.
Translated by L. Yu. Kolotilina.
Translated fromZapiski Nauchnykh Seminarov POMI, Vol. 202, 1992, pp. 18–25. 相似文献
6.
A. A. Karatsuba 《Mathematical Notes》1999,66(5):565-569
In this paper estimates of incomplete Kloosterman double sums with weights are obtained.
Translated fromMatematicheskie Zametki, Vol. 66, No. 5, pp. 682–687, November, 1999. 相似文献
7.
If π is a set of primes, a finite group G is block π-separated if for every two distinct irreducible complex characters α, β ∈ Irr(G) there exists a prime p ∈ π such that α and β lie in different Brauer p-blocks. A group G is block separated if it is separated by the set of prime divisors of |G|. Given a set π with n different primes, we construct an example of a solvable π-group G which is block separated but it is not separated by every proper subset of π.
Received: 22 December 2004 相似文献
8.
L. A. Molotkov 《Journal of Mathematical Sciences》2006,132(1):83-90
The propagation of seismic waves in block two- and three-dimensional media is investigated. These media are composed of identical
cells in which there are several fluid blocks and one elastic block. For these media, effective models, which are anisotropic
fluids, are established. Formulas for the velocities of propagation in these fluids are derived and investigated. A special
investigation is carried out in the cases where the elastic block occupies almost the entire cell or where the relative volume
of the elastic block is very small. Bibliography: 9 titles.
Dedicated to P. V. Krauklis on the occasion of his seventieth birthday
__________
Translated from Zapiski Nauchnykh Seminarov POMI, Vol. 308, 2004, pp. 147–160. 相似文献
9.
M. T. Bystrytskyi 《Journal of Mathematical Sciences》2000,102(1):3733-3739
We propose an algorithm for calculating solutions of a difference Dirichlet problem for the Poisson equation on a seven-point
nonorthogonal pattern of a rectangular grid. The algorithm is based on the incomplete reduction method. Bibliography: 4 titles.
Translated fromObchyslyuval'na ta Prykladna Matematyka, No. 81, 1997, pp. 15–22. 相似文献
10.
W. D. Wallis 《Israel Journal of Mathematics》1971,10(4):457-464
Recent work on integral equivalence of Hadamard matrices and block designs is generalized in two directions. We first determine
the two greatest invariants under integral equivalence of the incidence matrix of a symmetric balanced incomplete block design.
This enables us to write down all the invariants in the case wherek −λ is square-fre. Some other results on the sequence of invariants are presented. Secondly we consider the existence of inequivalent
Hadamard matrices under integral equivalence. We show that if there is a skew-Hadamard matrix of order 8m then there are two inequivalent Hadamard matrices of order 16m, that and there are precisely eleven inequivalent Hadamard matrices of order 32. 相似文献
11.
E. M. Vechtomov 《Mathematical Notes》1997,62(5):575-580
The latticeA(X) of all possible subalgebras of the ring of all continuous ℝ-valued functions defined on an ℝ-separated spaceX is considered. A topological space is said to be a Hewitt space if it is homeomorphic to a closed subspace of a Tychonoff
power of the real line ℝ. The main achievement of the paper is the proof of the fact that any Hewitt spaceX is determined by the latticeA(X). An original technique of minimal and maximal subalgebras is applied. It is shown that the latticeA(X) is regular if and only ifX contains at most two points.
Translated fromMatematicheskie Zametki, Vol. 62, No. 5, pp. 687–693, November, 1997.
Translated by A. I. Shtern 相似文献
12.
L. A. Molotkov 《Journal of Mathematical Sciences》1997,86(3):2721-2734
The system under consideration consists of equal rectangular blocks. Each block contains four homogeneous elastic isotropic
media with slide contacts on the interfaces between the media. For this system an effective four-phase model is deduced. By
analyzing the equations of the effective model, the fronts and velocities along axes are determined. Bibliography: 7 titles.
Translated fromZapiski Nauchnykh Seminarov POMI, Vol. 218, 1994, pp. 96–117.
This work was supported by the Russian Foundation of Fundamental Research (Grant 93-011-16148).
Translated by L. A. Molotkov. 相似文献
13.
An (α,n)-arc in a 2-design is a set ofn points of the design such that any block intersects it in at most α points. For such an arc,n is bounded by 1+(r(α−1)/λ), with equality if and only if every block meets the arc in either 0 or α points. An (α,n) arc with equality in above is said to be maximal.
A maximal block arc can be dually defined. This generalizes the notion of an oval (α=2) in a symmetric design due to Asmus
and van Lint. The aim of this paper is to study the infinite family of possibly extendable symmetric designs other than the
Hadamard design family and their related designs using maximal arcs. It is shown that the extendability corresponds to the
existence of a proper family of maximal arcs. A natural duality between point and block arcs is established, which among other
things implies a result of Cameron and van Lint that extendability of a given design in this family is equivalent to extendability
of its dual. Similar results are proved for other related designs. 相似文献
14.
V. A. Belonogov 《Algebra and Logic》2000,39(3):155-159
A character table X of a finite group is broken up into four squares: A, B, C, and D. We establish relations via which ranks
of the matrices inX are connected. In particular, ifX is an l × l-matrix, A is an s × t-matrix, and, moreover, the squares A and C are opposite, thenr(A)=r(C) + s + t − l; here.r(M) is the rank of a matrix M. Associated with such each block ofX is some integral nonnegative parameter m, and we have m=0 iff A, B, C, and D are active fragments ofX.
Supported by RFFR grant No. 96-01-00488.
Translated fromAlgebra i Logika, Vol. 39, No. 3, pp. 273–279, May–June, 2000. 相似文献
15.
Zhongxiao Jia 《BIT Numerical Mathematics》1995,35(4):516-539
The incomplete orthogonalization method (IOM) proposed by Saad for computing a few eigenpairs of large nonsymmetric matrices is generalized into a block incomplete orthogonalization method (BIOM). It is studied how the departure from symmetry A – A
H
affects the conditioning of the block basis vectors generated by BIOM, and some relationships are established between the approximate eigenpairs obtained by BIOM and Ritz pairs. It is proved that BIOM behaves much like generalized block Lanczos methods if the basis vectors of the block Krylov subspace generated by it are strongly linearly independent. However, it is shown that BIOM may generate a nearly linearly dependent basis for a general nonsymmetric matrix. Numerical experiments illustrate the convergence behavior of BIOM.This work was supported in part by the Graduiertenkolleg at the University of Bielefeld, Germany. 相似文献
16.
N. N. Ural'tseva 《Journal of Mathematical Sciences》2000,101(5):3570-3576
For the simplest elliptic obstacle problem, the behavior of the free boundary in the vicinity of the points where it meets
the prescribed boundary of a domain is studied. The previous result of the author on the C1 smoothness of the boundary ∂N of the noncoincidence set is improved. The Lipschitz condition on ∂N assumed earlier is shown to be superfluous. Bibliography: 4 titles.
Dedicated to O. A. Ladyzhenskaya on her jubilee
Translated fromZapiski Nauchnykh Seminarov POMI, Vol. 249, 1997, pp. 303–312.
Translated by I. Kostin. 相似文献
17.
A. Dey 《Annals of the Institute of Statistical Mathematics》1970,22(1):389-393
Summary A method of construction of balanced ternary designs using affine α-resolvable balanced incomplete block designs is presented. 相似文献
18.
Super-simple designs are useful in constructing codes and designs such as superimposed codes and perfect hash families. In
this article, we investigate the existence of a super-simple (ν, 5, 5) balanced incomplete block design and show that such
a design exists if and only if ν ≡ 1 (mod 4) and ν ≥ 17 except possibly when ν = 21. Applications of the results to optical orthogonal codes are also mentioned.
Research supported by NSERC grant 239135-01. 相似文献
19.
We propose a variant of parallel block incomplete factorization preconditioners for a symmetric block-tridiagonalH-matrix. Theoretical properties of these block preconditioners are compared with those of block incomplete factorization preconditioners
for the corresponding comparison matrix. Numerical results of the preconditioned CG(PCG) method using these block preconditioners
are compared with those of PCG using other types of block incomplete factorization preconditioners. Lastly, parallel computations
of the block incomplete factorization preconditioners are carried out on the Cray C90. 相似文献
20.
The problem of estimation of a nonobservable component θt for a two-dimensional process (θt, ξt) of random evolution (θ
t,ξt);xt, 0≤t≤T, is investigated on the basis of observations of ξs. s≤t, where x
t is a homogeneous Markov process with infinitesimal operator Q. Applications to stochastic models of a (B,S)-market of securities is described under conditions of incomplete market.
Translated from Ukrainskii Matematicheskii Zhurnal, Vol. 50, No. 12, pp. 1701–1705, December, 1998. 相似文献