首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 60 毫秒
1.
This article improves results of Hamada, Helleseth and Maekawa on minihypers in projective spaces and linear codes meeting the Griesmer bound.In [10,12],it was shown that any -minihyper, with , where , is the disjoint union of points, lines,..., -dimensional subspaces. For q large, we improve on this result by increasing the upper bound on non-square, to non-square, square, , and (4) for square, p prime, p<3, to . In the case q non-square, the conclusion is the same as written above; the minihyper is the disjoint union of subspaces. When q is square however, the minihyper is either the disjoint union of subspaces, or the disjoint union of subspaces and one subgeometry . For the coding-theoretical problem, our results classify the corresponding codes meeting the Griesmer bound.  相似文献   

2.
The paper deals with the system
where and are -matrix functions; is a boundary control; is the solution. The singularities of the fundamental solution corresponding to the controls ( is the Dirac -function) are under investigation. In the case of , the singularities of the fundamental solution are described in terms of the standard scale . In the presence of points an interesting effect occurs: singularities of intermediate (fractional) orders appear. Bibliography: 1 title.  相似文献   

3.
We study the complexity of a noninterior path-following method for the linear complementarity problem. The method is based on the Chen–Harker–Kanzow–Smale smoothing function. It is assumed that the matrix M is either a P-matrix or symmetric and positive definite. When M is a P-matrix, it is shown that the algorithm finds a solution satisfying the conditions Mx-y+q=0 and in at most
Newton iterations; here, and µ0 depend on the initial point, l(M) depends on M, and > 0. When Mis symmetric and positive definite, the complexity bound is
where
and are the smallest and largest eigenvalues of M.  相似文献   

4.
Pekarskii  A. A. 《Mathematical Notes》2002,72(1-2):230-236
In the open disk of the complex plane, we consider the following spaces of functions: the Bloch space ; the Hardy--Sobolev space ; and the Hardy--Besov space . It is shown that if all the poles of the rational function R of degree n, , lie in the domain , then , where and depends only on . The second of these inequalities for the case of the half-plane was obtained by Semmes in 1984. The proof given by Semmes was based on the use of Hankel operators, while our proof uses the special integral representation of rational functions.  相似文献   

5.
Let h(d) be the class number of the field and let be the Lévy constant. A connection between these constants is studied. It is proved that if d is large, then the value h(d) increases, roughly speaking, at the rate as grows. A similar result is obtained in the case where the value is close to , i.e., to the least possible value. In addition, it is shown that the interval contains no values of for prime p such that p 3 (mod 4). As a corollary, a new criterion for the equality h(d)=1 is obtained. Bibliography: 14 titles.  相似文献   

6.
Bakhvalov  A. N. 《Mathematical Notes》2002,72(3-4):454-465
In this paper, we consider the behavior of rectangular partial sums of the Fourier series of continuous functions of several variables with respect to the trigonometric system. The Fourier series is called -convergent if the limit of rectangular partial sums over all indices for which for all j and k exists. In the space of arbitrary even dimension 2m we construct an example of a continuous function with an estimate of the modulus of continuity such that its Fourier series is -divergent everywhere for any .  相似文献   

7.
Let be the Hecke eigenbasis of the space of -cusp forms of weight 2. Let p be a prime. Let be the Hecke L-series of form . The following statements are proved:
and
We also give a correct proof of a previous author's theorem on automorphic L-functions. Bibliography: 12 titles.  相似文献   

8.
Horst Alzer 《Acta Appl Math》1995,38(3):305-354
In this survey paper, we present refinements, extensions, and variants of the inequality
  相似文献   

9.
The following classes of functions analytic in the unit disk are considered:
and
where is the Nevanlinna characteristic and is a properly changing positive function on (0,1]. Necessary and sufficient conditions on are established under which the classes and are invariant under the operators of differentiation and integration. Bibliography: 7 titles.  相似文献   

10.
The paper deals with the problem of recovering the parameters (functions) and of the Maxwell dynamical system
(tan is the tangent component; is a solution) by the response operator ( is the normal). The parameters determine the velocity , the c-metric , and the time . It is shown that for any fixed , the operator determines and in uniquely. Bibliography: 15 titles.  相似文献   

11.
We compute the joint entropy ofd commuting automorphisms of a compact metrizable group. LetR d = [u 1 ±1 ,...,[d 1 ±1 ] be the ring of Laurent polynomials ind commuting variables, andM be anR d -module. Then the dual groupX M ofM is compact, and multiplication onM by each of thed variables corresponds to an action M of d by automorphisms ofX M . Every action of d by automorphisms of a compact abelian group arises this way. IffR d , our main formula shows that the topological entropy of is given by
  相似文献   

12.
In this paper the set of minimal periods of periodic points of 1-norm nonexpansive maps is studied. This set is denoted by R(n). The main goal is to present a characterization of R(n) by arithmetical and combinatorial constraints. More precisely, it is shown that , where denotes the set of periods of restricted admissible arrays on 2n symbols. The important point of this equality is that is determined by arithmetical and combinatorial constraints only, and that it can be computed in finite time. By using this equality the set R(n) is computed for . Furthermore it is shown that the largest element of R(n) satisfies:   相似文献   

13.
For a positive real parameter t, real numbers , , and , we consider sums , where is the rounding error function, i.e.\ . Generalizing and improving the main result of Part I of the paper we show that there exists an absolute constant such that for all , and all . Further, we give applications concerning the circle problem with linear, polynomial, and general weight.  相似文献   

14.
Let be i.i.d. random variables and let, for each and . It is shown that a.s. whenever the sequence of self-normalized sums S n /V n is stochastically bounded, and that this limsup is a.s. positive if, in addition, X is in the Feller class. It is also shown that, for X in the Feller class, the sequence of self-normalized sums is stochastically bounded if and only if   相似文献   

15.
Let log . We prove that there exist non-denumerably many pairwise not equivalent irrational numbers such that and where qn() denotes the denominator of the nth convergent of .  相似文献   

16.
Let h(d) be the class number of properly equivalent primitive binary quadratic forms ax2+bxy+cy2 with discriminant d=b2-4ac. The behavior of h(5p2), where p runs over primes, is studied. It is easy to show that there are few discriminants of the form 5p2 with large class numbers. In fact, one has the estimate
x^{1 - \delta } \} \ll x^{2\delta } ,$$ " align="middle" vspace="20%" border="0">
where is an arbitrary constant number in (0;1/2). Assume that (x) is a positive function monotonically increasing for x and (x). If
, then (assuming the validity of the extended Riemann hypothesis for certain Dedekind zeta-functions) it is proved that
\alpha (x)} \right\} \asymp \frac{{\pi (x)}}{{\alpha (x)}}.$$ " align="middle" vspace="20%" border="0">
It is also proved that for an infinite set of p with one has the inequality
where log k p is the k-fold iterated logarithm (k is an arbitrary integer, k3). Results on mean values of h(5p 2 ) are also obtained. Similar facts are true for the residual indices of an integer a2 modulo p:
where o(a,p) is the order of a modulo p. Bibliography: 13 titles.  相似文献   

17.
We apply a variant of the method of the extremal metric to some problems concerning extremal decompositions and related problems. Let be a system of distinct points on and let be the family of all systems of nonoverlapping simply connected domains on such that . Let
where is the reduced module of the domain with respect to the point . At present, the problem concerning the value was solved completely for . In this work, we continue the previous author's investigations and consider the case . In addition, we consider the problem concerning the maximum of the sum
in the family introduced above, where , are arbitrary points of the circle , and is a positive number. We prove that if , then the maximum is attained only for systems of equidistant points of the circle . For , this result was obtained earlier by Dubinin who applied the method of symmetrization. It is shown that if , where is an even number, then equidistant points of the circle do not realize the indicated maximum. Bibliography: 11 titles.  相似文献   

18.
Brightwell  Graham R.  Tetali  Prasad 《Order》2003,20(4):333-345
Let L(Q t ) denote the number of linear extensions of the t-dimensional Boolean lattice Q t . We use the entropy method of Kahn to show that
where the logarithms are base 2. We also find the exact maximum number of linear extensions of a d-regular bipartite order on n elements, in the case when n is a multiple of 2d.  相似文献   

19.
In this paper we consider the weakly coupled elliptic system with critical growth
where a, b, c, d are C 1-functions defined in a bounded regular domain of N . Here we construct families of solutions which blow-up and concentrate at some points in as the positive parameter goes to zero.*The authors are supported by M.I.U.R., project Metodi variazionali e topologici nello studio di fenomeni non lineari.  相似文献   

20.
We study the inhomogeneous semilinear wave equations on with initial values and ,where is a noncompact, complete manifold. We founda new critical behavior in the following sense. There exists ap* > 0. When 1 < p p*, the above problem hasno global solution for any nonnegative not identicallyzero and for any and ; when the problem has a global solution for some and some and . If , which is equipped with the Euclideanmetric, then . If we show that belongs to the blow upcase. Although homogeneous semilinear wave equations are known to exhibit acritical behavior for a long time, this seems to be the first result oninhomogeneous ones.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号