共查询到20条相似文献,搜索用时 10 毫秒
1.
《Discrete Mathematics》2020,343(5):111795
Pairs of complementary sequences such as Golay pairs have zero sum autocorrelation at all non-trivial phases. Several generalizations are known where conditions on either the autocorrelation function, or the entries of the sequences are altered. We aim to unify most of these ideas by introducing autocorrelation functions that apply to any sequences with entries in a set equipped with a ring-like structure which is closed under multiplication and contains multiplicative inverses. Depending on the elements of the chosen set, the resulting complementary pairs may be used to construct a variety of combinatorial structures such as Hadamard matrices, complex generalized weighing matrices, and signed group weighing matrices. We may also construct quasi-cyclic and quasi-constacyclic linear codes which over finite fields of order less than 5 are also Hermitian self-orthogonal. As the literature on binary and ternary Golay sequences is already quite deep, one intention of this paper is to survey and assimilate work on more general pairs of complementary sequences and related constructions of combinatorial objects, and to combine the ideas into a single theoretical framework. 相似文献
2.
We argue that a Golay complementary sequence is naturally viewed as a projection of a multi-dimensional Golay array. We present a three-stage process for constructing and enumerating Golay array and sequence pairs:
- 1.
- construct suitable Golay array pairs from lower-dimensional Golay array pairs;
- 2.
- apply transformations to these Golay array pairs to generate a larger set of Golay array pairs; and
- 3.
- take projections of the resulting Golay array pairs to lower dimensions.
3.
Let H0 (respectively H∞) denote the class of commuting pairs of subnormal operators on Hilbert space (respectively subnormal pairs), and for an integer k?1 let Hk denote the class of k-hyponormal pairs in H0. We study the hyponormality and subnormality of powers of pairs in Hk. We first show that if (T1,T2)∈H1, the pair may fail to be in H1. Conversely, we find a pair (T1,T2)∈H0 such that but (T1,T2)∉H1. Next, we show that there exists a pair (T1,T2)∈H1 such that is subnormal (for all m,n?1), but (T1,T2) is not in H∞; this further stretches the gap between the classes H1 and H∞. Finally, we prove that there exists a large class of 2-variable weighted shifts (T1,T2) (namely those pairs in H0 whose cores are of tensor form (cf. Definition 3.4)), for which the subnormality of and does imply the subnormality of (T1,T2). 相似文献
4.
In this paper we develop the notion of contact orders for pairs of continuous self-maps (f, g) from ℝn, showing that the set Con(f, g) of all possible contact orders between f and g is a topological invariant (we remark that Con(f, id) = Per(f)). As an interesting application of this concept, we give sufficient conditions for the graphs of two continuous self-maps
from ℝ intersect each other. We also determine the ordering of the sets Con(f, 0) and Con(f, h), for h ∈ Hom(ℝ) such that f ∘ h = h ∘ f. For this latter set we obtain a generalization of Sharkovsky’s theorem. 相似文献
5.
The discrete Ablowitz-Ladik hierarchy with four potentials and the Hamiltonian structures are derived. Under a constraint between the potentials and eigenfunctions, the nonlinearization of the Lax pairs associated with the discrete Ablowitz-Ladik hierarchy leads to a new symplectic map and a class of finite-dimensional Hamiltonian systems. The generating function of the integrals of motion is presented, by which the symplectic map and these finite-dimensional Hamiltonian systems are further proved to be completely integrable in the Liouville sense. Each member in the discrete Ablowitz-Ladik hierarchy is decomposed into a Hamiltonian system of ordinary differential equations plus the discrete flow generated by the symplectic map. 相似文献
6.
Chong Zhang 《Journal of Number Theory》2013,133(9):3057-3064
Following Roberts? work in the case of orthogonal-symplectic similitude dual pairs, we study the local theta correspondence for unitary similitude dual pairs over a p-adic field. 相似文献
7.
蒋光洁 《纯粹数学与应用数学》2010,26(5):745-750
研究Banach空间中L-Lipschitzian映射对的公共不动点逼近问题.设E表示实Banach空间,K是E中的非空闭凸子集,T,S:K→K是L-Lipschitzian映射,{xn].是带平均误差项的迭代序列,我们给出了{xn)强收敛于T和S的一个公共不动点的充分必要条件,这一结果推广了Banach空间不动点逼近定理. 相似文献
8.
We introduce a family of reductions for removing proper and homogeneous pairs of cliques from a graph G. This family generalizes some routines presented in the literature, mostly in the context of claw-free graphs. These reductions can be embedded in a simple algorithm that in at most |E(G)| steps builds a new graph G′ without proper and homogeneous pairs of cliques, and such that G and G′ agree on the value of some relevant invariant (or property). 相似文献
9.
Binary Golay sequence pairs exist for lengths 2, 10 and 26 and, by Turyn's product construction, for all lengths of the form 2a10b26c where a, b, c are non‐negative integers. Computer search has shown that all inequivalent binary Golay sequence pairs of length less than 100 can be constructed from five “seed” pairs, of length 2, 10, 10, 20 and 26. We give the first complete explanation of the origin of the length 26 binary Golay seed pair, involving a Barker sequence of length 13 and a related Barker sequence of length 11. This is the special case m=1 of a general construction for a length 16m+10 binary Golay pair from a related pair of Barker sequences of length 8m+5 and 8m+3, for integer m≥0. In the case m=0, we obtain an alternative explanation of the origin of one of the length 10 binary Golay seed pairs. The construction cannot produce binary Golay sequence pairs for m>1, having length greater than 26, because there are no Barker sequences of odd length greater than 13. © 2009 Wiley Periodicals, Inc. J Combin Designs 17: 478–491, 2009 相似文献
10.
11.
李效敏 《纯粹数学与应用数学》2002,18(2):109-115
研究了具有三个CM公共小函数对,一个IM公共小函数对的亚纯函数的惟一性,改进了李平与杨重骏,Brosch等人的有关结果,用例子说明本文的结果是最佳的. 相似文献
12.
Wei-Yann Tsai 《Statistics & probability letters》1985,3(5):281-286
Semi-Markov models are used in a study of censored, matched pairs. A partial likelihood function is obtained in the presence of univariate censoring for a class of semi-Markov models. A test statistics is derived for testing treatment effects of matched-pairs based on this partial likelihood function. Some directions for further generalization are also outlined. 相似文献
13.
14.
15.
John H. Clifford Michael G. Dabkowski 《Journal of Mathematical Analysis and Applications》2005,305(1):183-196
We find the singular values and corresponding Schmidt pairs of a compact composition operator Cφ induced by φ(z)=az+b, where |a|+|b|<1, on the classical Hardy space. We do so by solving a functional equation that is a generalization of Schröder's equation: find a function f, holomorphic on the open unit disc, and a complex number λ such that G(z)f(ψ(z))=λf(ψ(z)), where ψ is a holomorphic self-map of the open unit disc with an interior fixed point and G is a bounded holomorphic function on the open unit disc. In addition, we find the spectrum of the weighted composition operator MGCψ. 相似文献
16.
《Journal of Graph Theory》2018,89(3):266-287
The Erdős–Hajnal conjecture states that for every given undirected graph H there exists a constant such that every graph G that does not contain H as an induced subgraph contains a clique or a stable set of size at least . The conjecture is still open. Its equivalent directed version states that for every given tournament H there exists a constant such that every H‐free tournament T contains a transitive subtournament of order at least . In this article, we prove that for several pairs of tournaments, H1 and H2, there exists a constant such that every ‐free tournament T contains a transitive subtournament of size at least . In particular, we prove that for several tournaments H, there exists a constant such that every ‐free tournament T, where stands for the complement of H, has a transitive subtournament of size at least . To the best of our knowledge these are first nontrivial results of this type. 相似文献
17.
Dirar Rebah 《Journal of Mathematical Analysis and Applications》2006,317(1):14-27
This study proves an existence of a steady vortex pairs in two phase shear flow in plane domain. The method was used is a variational principle in which a functional related to the kinetic energy can be maximised over the set where the vorticity being a rearrangement of a prescribed function. 相似文献
18.
Jean-Michel Vallin 《Journal of Functional Analysis》2008,254(8):2040-2068
In this work we give a generalization of matched pairs of (finite) groups to describe a general class of depth two inclusions of factor von Neumann algebras and the C∗-quantum groupoids associated with, using double groupoids. 相似文献
19.
通过讨论矩的存在性与部分和尾概率级数收敛性的关系,给出了PA序列部分和的完全收敛性,获得了PA序列与独立序列类似的强极限性质. 相似文献