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1.
We give a constructive proof of the existence of a completely integrable Pfaff system with infinitely differentiable bounded coefficient matrices and with an arbitrary disconnected lower characteristic set of positive Lebesgue m-measure. 相似文献
2.
For any positive integers n ≥ 1 and m ≥ 2, we give a constructive proof of the existence of linear n-dimensional Pfaff systems with m-dimensional time and with infinitely differentiable coefficient matrices such that the characteristic and lower characteristic sets of these systems are given sets that are the graphs of a concave continuous function and a convex continuous function, respectively, defined and monotone decreasing on simply connected closed bounded convex domains of the space ?m?1. 相似文献
3.
A normal subgroup N of a finite group G is called n-decomposable in G if N is the union of n distinct G-conjugacy classes. We study the structure of nonperfect groups in which every proper nontrivial normal subgroup is m-decomposable, m+1-decomposable, or m+2-decomposable for some positive integer m. Furthermore, we give classification for the soluble case. 相似文献
4.
We generalize Green’s lemma and Green’s theorem for usual binary semigroups to (n,m)-semigroups, define and describe the regularity for an element of an (n,m)-semigroup, give some criteria for an element of an (n,m)-semigroup to be invertible, and further apply the invertibility for (n,m)-semigroups to (n,m)-groups and give some equivalent characterizations for (n,m)-groups. We establish Hosszú-Gluskin theorems for (n,m)-semigroups in two cases, as generalizations of the corresponding theorems for n-groups. 相似文献
5.
Jan De Beule Patrick Govaerts Anja Hallez Leo Storme 《Designs, Codes and Cryptography》2009,50(2):187-201
Minihypers are substructures of projective spaces introduced to study linear codes meeting the Griesmer bound. Recently, many
results in finite geometry were obtained by applying characterization results on minihypers (De Beule et al. 16:342–349, 2008;
Govaerts and Storme 4:279–286, 2004; Govaerts et al. 28:659–672, 2002). In this paper, using characterization results on certain
minihypers, we present new results on tight sets in classical finite polar spaces and weighted m-covers, and on weighted m-ovoids of classical finite generalized quadrangles. The link with minihypers gives us characterization results of i-tight sets in terms of generators and Baer subgeometries contained in the Hermitian and symplectic polar spaces, and in terms
of generators for the quadratic polar spaces. We also present extendability results on partial weighted m-ovoids and partial weighted m-covers, having small deficiency, to weighted m-covers and weighted m-ovoids of classical finite generalized quadrangles. As a particular application, we prove in an alternative way the extendability
of 53-, 54-, and 55-caps of PG(5,3), contained in a non-singular elliptic quadric Q−(5,3), to 56-caps contained in this elliptic quadric Q−(5,3).
相似文献
6.
The purpose of this paper is to investigate central elements in distribution algebras D i s t(G) of general linear supergroups G = G L(m|n). As an application, we compute explicitly the center of D i s t(G L(1|1)) and its image under Harish-Chandra homomorphism. 相似文献
7.
Michael I. Ganzburg 《Journal d'Analyse Mathématique》2018,135(2):389-411
Let μ be a measurewith a k-concave density W on an open convex set V in Rm, that is, W is an integrable weight satisfying the condition for all x ∈ V, y ∈ V, and α ∈ [0, 1]. In this paper, we first show that the Fradelizi μ-distributional inequalities for polynomials P of m variables are sharp for each m and k ∈ (?1/m,∞]. Classes of extremal sets V, weights W, and polynomials P for these inequalities are presented. Sharpness of the Bobkov-Nazarov-Fradelizi dilation-type inequalities is established as well. Second, we find efficient conditions for k-concavity of a weight W and obtain new sharp polynomial inequalities.
相似文献
$$W(ax + (1 - a)y) \geqslant {(a{W^K}(x) + (1 - a){W^K}(y))^{1/k}},k \in ( - 1/m,\infty ]$$
8.
The Existence of LHMTS(<Emphasis Type="Italic">m</Emphasis><Superscript><Emphasis Type="Italic">v</Emphasis></Superscript>) and LHDTS(<Emphasis Type="Italic">m</Emphasis><Superscript><Emphasis Type="Italic">v</Emphasis></Superscript>) 下载免费PDF全文
In this article, we establish the existence of an LHMTS(mv) for v ≡ 2 (mod 6) and m≡ 3 (mod 6). Thus there exists an LHMTS(mv) if and only if v(v-1)m2 ≡ 0 (mod 3) except possibly for v=6, m≡ 1, 5 (mod 6) and m≠1. In the similar way, the existence of LHDTS(mv) is completely determined, i.e., there exists an LHDTS(mv) if and only if v(v-1)m2 ≡ 0 (mod 3). 相似文献
9.
For X, Y ∈ Mn,m it is said that X is gut-majorized by Y, and we write X ?gutY, if there exists an n-by-n upper triangular g-row stochastic matrix R such that X = RY. Define the relation ~gut as follows. X ~gutY if X is gut-majorized by Y and Y is gut-majorized by X. The (strong) linear preservers of ?gut on ?n and strong linear preservers of this relation on Mn,m have been characterized before. This paper characterizes all (strong) linear preservers and strong linear preservers of ~gut on ?n and Mn,m. 相似文献
10.
The concept of a tight set of points of a generalised quadrangle was introduced by S. E. Payne in 1987, and that of an m-ovoid of a generalised quadrangle was introduced by J. A. Thas in 1989, and we unify these two concepts by defining intriguing sets of points. We prove that every intriguing set of points in a generalised quadrangle is an m-ovoid or a tight set, and we state an intersection result concerning these objects. In the classical generalised quadrangles,
we construct new m-ovoids and tight sets. In particular, we construct m-ovoids of W(3,q), q odd, for all even m; we construct (q+1)/2-ovoids of W(3,q) for q odd; and we give a lower bound on m for m-ovoids of H(4,q
2). 相似文献
11.
The theory of overpartitions is applied to determine formulas for the number of partitions of n where (1) the mth largest part is k and (2) the mth smallest part is k. 相似文献
12.
Philipp Hoffmann Michael Mackey Mícheál Ó Searcóid 《Integral Equations and Operator Theory》2011,71(3):389-405
A bounded linear operator T on a Banach space X is called an (m, p)-isometry if it satisfies the equation \({\sum_{k=0}^{m}(-1)^{k} {m \choose k}\|T^{k}x\|^{p}=0}\) , for all \({x \in X}\) . In this paper we study the structure which underlies the second parameter of (m, p)-isometric operators. We concentrate on determining when an (m, p)-isometry is a (μ, q)-isometry for some pair (μ, q). We also extend the definition of (m, p)-isometry, to include p = ∞ and study basic properties of these (m, ∞)-isometries. 相似文献
13.
BATOOL ZAREI JALAL ABADI HOSEIN FAZAELI MOGHIMI 《Proceedings Mathematical Sciences》2017,127(2):251-261
Let R be a commutative ring with 1 ≠ 0 and U(R) be the set of all unit elements of R. Let m, n be positive integers such that m > n. In this article, we study a generalization of n-absorbing ideals. A proper ideal I of R is called an (m, n)-absorbing ideal if whenever a 1?a m ∈I for a 1,…, a m ∈R?U(R), then there are n of the a i ’s whose product is in I. We investigate the stability of (m, n)-absorbing ideals with respect to various ring theoretic constructions and study (m, n)-absorbing ideals in several commutative rings. For example, in a Bézout ring or a Boolean ring, an ideal is an (m, n)-absorbing ideal if and only if it is an n-absorbing ideal, and in an almost Dedekind domain every (m, n)-absorbing ideal is a product of at most m ? 1 maximal ideals. 相似文献
14.
In this paper, we are interested in a generalization of the notion of sum-free sets. We address a conjecture rst made in the 90s by Chung and Goldwasser. Recently, after some computer checks, this conjecture was formulated again by Matolcsi and Ruzsa, who made a rst signicant step towards it. Here, we prove the full conjecture by giving an optimal upper bound for the Lebesgue measure of a 3-sum-free subset A of [0; 1], that is, a set containing no solution to the equation x+y=3z where x, y and z are restricted to belong to A. We then address the inverse problem and characterize precisely, among all sets with that property, those attaining the maximal possible measure. 相似文献
15.
Erik A. van Doorn 《TOP》2011,19(2):336-350
We consider the M/M/N/N+R service system, characterized by N servers, R waiting positions, Poisson arrivals and exponential service times. We discuss representations and bounds for the rate of
convergence to stationarity of the number of customers in the system, and study its behaviour as a function of R, N and the arrival rate λ, allowing λ to be a function of N. 相似文献
16.
In this paper we consider n-poised planar node sets, as well as more special ones, called G C n sets. For the latter sets each n-fundamental polynomial is a product of n linear factors as it always holds in the univariate case. A line ? is called k-node line for a node set \(\mathcal X\) if it passes through exactly k nodes. An (n + 1)-node line is called maximal line. In 1982 M. Gasca and J. I. Maeztu conjectured that every G C n set possesses necessarily a maximal line. Till now the conjecture is confirmed to be true for n ≤ 5. It is well-known that any maximal line M of \(\mathcal X\) is used by each node in \(\mathcal X\setminus M, \)meaning that it is a factor of the fundamental polynomial. In this paper we prove, in particular, that if the Gasca-Maeztu conjecture is true then any n-node line of G C n set \(\mathcal {X}\) is used either by exactly \(\binom {n}{2}\) nodes or by exactly \(\binom {n-1}{2}\) nodes. We prove also similar statements concerning n-node or (n ? 1)-node lines in more general n-poised sets. This is a new phenomenon in n-poised and G C n sets. At the end we present a conjecture concerning any k-node line. 相似文献
17.
(t,m,s)-Nets were defined by Niederreiter [Monatshefte fur Mathematik, Vol. 104 (1987) pp. 273–337], based on earlier work by Sobol’ [Zh. Vychisl Mat. i mat. Fiz, Vol. 7 (1967) pp. 784–802], in the context of quasi-Monte Carlo methods of numerical integration. Formulated in combinatorial/coding theoretic terms a binary linear (m−k,m,s)2-net is a family of ks vectors in F2m satisfying certain linear independence conditions (s is the length, m the dimension and k the strength: certain subsets of k vectors must be linearly independent). Helleseth et al. [5] recently constructed (2r−3,2r+2,2r−1)2-nets for every r. In this paper, we give a direct and elementary construction for (2r−3,2r+2,2r+1)2-nets based on a family of binary linear codes of minimum distance 6.Communicated by: T. Helleseth 相似文献
18.
We prove the existence of a completely integrable Pfaff system ∂x/∂t
i
= A
i
(t)x, x ∈ R
n
, t = (t
1, t
2, t
3) ∈ R
+3, i = 1, 2, 3, with infinitely differentiable bounded coefficient matrices and with lower characteristic set being the union
of countably many segments in the space R
3. 相似文献
19.
Dieter Fiems Stijn De Vuyst Sabine Wittevrongel Herwig Bruneel 《Annals of Operations Research》2009,170(1):113-131
In this contribution we investigate higher-order loss characteristics for M/G/1/N queueing systems. We focus on the lengths of the loss and non-loss periods as well as on the number of arrivals during these
periods. For the analysis, we extend the Markovian state of the queueing system with the time and number of admitted arrivals
since the instant where the last loss occurred. By combining transform and matrix techniques, expressions for the various
moments of these loss characteristics are found. The approach also yields expressions for the loss probability and the conditional
loss probability. Some numerical examples then illustrate our results. 相似文献
20.
In this paper, we give the eigenvalues of the manifold Sp(n)/U(n). We prove that an eigenvalue λ
s
(f
2, f
2, …, f
n
) of the Lie group Sp(n), corresponding to the representation with label (f
1, f
2, ..., f
n
), is an eigenvalue of the manifold Sp(n)/U(n), if and only if f
1, f
2, …, f
n
are all even. 相似文献