共查询到20条相似文献,搜索用时 46 毫秒
1.
Ramakanth Kavuluru 《Designs, Codes and Cryptography》2009,53(2):75-97
The linear complexity of sequences is an important measure of the cryptographic strength of key streams used in stream ciphers.
The instability of linear complexity caused by changing a few symbols of sequences can be measured using k-error linear complexity. In their SETA 2006 paper, Fu et al. (SETA, pp. 88–103, 2006) studied the linear complexity and the
1-error linear complexity of 2
n
-periodic binary sequences to characterize such sequences with fixed 1-error linear complexity. In this paper we study the
linear complexity and the k-error linear complexity of 2
n
-periodic binary sequences in a more general setting using a combination of algebraic, combinatorial, and algorithmic methods.
This approach allows us to characterize 2
n
-periodic binary sequences with fixed 2- or 3-error linear complexity. Using this characterization we obtain the counting
function for the number of 2
n
-periodic binary sequences with fixed k-error linear complexity for k = 2 and 3. 相似文献
2.
In the last years there has been some interest in studying mappings in the fractional Sobolev space W1/2(, S1), see e.g., [4] [3] [15] [12] and the paper [5]. Motivated by these papers, we characterize here in the framework of Cartesian currents, see [9], the class of weak limits of sequences of smooth mappings with values into S1 with equibounded W1/2 energies. 相似文献
3.
Recently the first author presented exact formulas for the number of 2
n
-periodic binary sequences with given 1-error linear complexity, and an exact formula for the expected 1-error linear complexity
and upper and lower bounds for the expected k-error linear complexity, k ≥ 2, of a random 2
n
-periodic binary sequence. A crucial role for the analysis played the Chan–Games algorithm. We use a more sophisticated generalization
of the Chan–Games algorithm by Ding et al. to obtain exact formulas for the counting function and the expected value for the
1-error linear complexity for p
n
-periodic sequences over prime. Additionally we discuss the calculation of lower and upper bounds on the k-error linear complexity of p
n
-periodic sequences over .
相似文献
4.
Patrick LaVictoire 《Journal d'Analyse Mathématique》2011,113(1):241-263
We present a modified version of Buczolich and Mauldin’s proof that the sequence of square numbers is universally L
1-bad. We extend this result to a large class of sequences, including the dth powers and the set of primes. Furthermore, we show that any subsequence of the averages taken along these sequences is
also universally L
1-bad. 相似文献
5.
In this paper we characterize the Liouvillian integrable orthogonal separable Hamiltonian systems on T
2 for a given metric, and prove that the Hamiltonian flow on any compact level hypersurface has zero topological entropy. Furthermore,
by examples we show that the integrable Hamiltonian systems on T
2 can have complicated dynamical phenomena. For instance they can have several families of invariant tori, each family is bounded
by the homoclinic-loop-like cylinders and heteroclinic-loop-like cylinders. As we know, it is the first concrete example to
present the families of invariant tori at the same time appearing in such a complicated way.
This work is partially supported by the National Natural Science Foundation of China (Grant Nos. 10671123, 10231020), “Dawn”
Program of Shanghai Education Comission of China (Grant No. 03SG10) and Program for New Century Excellent Tatents in University
of China (Grant No. 050391) 相似文献
6.
In this article we construct a new simply connected symplectic 4-manifold with b2+=1 and c12=2 which is homeomorphic, but not diffeomorphic, to a rational surface by using rational blow-down technique. As a corollary, we conclude that a rational surface
admits an exotic smooth structure. Mathematics Subject Classification (2000) 53D05, 14J26, 57R55, 57R57 相似文献
7.
WeiLi ZhouHaiyun 《高校应用数学学报(英文版)》2005,20(2):175-182
By using the perturbation results of sums of ranges of accretive mappings of Calvert and Gupta (1978),the abstract results on the existence of solutions of a family of nonlinear boundary value problems in L^2 (Ω) are studied. The equation discussed in this paper and the methods used here are extension and complement to the corresponding results of Wei Li and He Zhen‘s previous papers. Especially,some new techniques are used in this paper. 相似文献
8.
R. N. Karasev 《Discrete and Computational Geometry》2008,39(4):766-777
In this paper, we consider finite families of convex sets in ℝ
d
such that every d or fewer sets of the family have a common point. For some families of this type, we give upper bounds on the size of a finite
set intersecting all sets of the family.
This research was supported by the Russian Foundation for the Basic Research Grants No. 03-01-00801 and 06-01-00648, and by
the President of the Russian Federation Grant No. MK-5724.2006.1. 相似文献
9.
We consider an M X /M/c queue with catastrophes and state-dependent control at idle time. Properties of the queues which terminate when the servers become idle are first studied. Recurrence, equilibrium distribution, and equilibrium queue-size structure are studied for the case of resurrection and no catastrophes. All of these properties and the first effective catastrophe occurrence time are then investigated for the case of resurrection and catastrophes. In particular, we obtain the Laplace transform of the transition probability for the absorbing M X /M/c queue. 相似文献
10.
We investigate two classes of orthonormal bases for L^2([0, 1)^n). The exponential parts of those bases are multi-knot piecewise linear functions which are called spectral sequences. We characterize the multi-knot piecewise linear spectral sequences and give an application of the first class of piecewise linear spectral sequences. 相似文献
11.
Ramification in complete discrete valuation fields is studied. For the case of a perfect residue field, there is a well-developed theory of ramification groups. Hyodo introduced the concept of ramification depth associated with the different of an extension and obtained an inequality that combines the concept of ramification depth in a degree p2 cyclotomic extension with the concept of ramification depth in a degree p subextension. The paper gives a detailed consideration of the structure of degree p2 extensions that can be obtained by a composite of two degree p extensions. In this case, it is not required that the residue field be perfect. Using the concepts of wild and ferocious extensions and the defect of the main unit, degree p2 extensions are classified and more accurate estimates for the ramification depth are obtained. In a number of cases, exact formulas for ramification depth are presented. 相似文献
12.
In this paper, geometric interpolation by G
1 cubic spline is studied. A wide class of sufficient conditions that admit a G
1 cubic spline interpolant is determined. In particular, convex data as well as data with inflection points are included. The
existence requirements are based upon geometric properties of data entirely, and can be easily verified in advance. The algorithm
that carries out the verification is added.
AMS subject classification (2000) 65D05, 65D07, 65D17 相似文献
13.
Romain Dujardin 《Mathematische Annalen》2003,325(4):745-765
In this paper we study laminar currents in ℙ2. Given a sequence of irreducible algebraic curves (C
n
) converging in the sense of currents to T, we find geometric conditions on the curves ensuring that the limit current T is laminar. This criterion is then applied to meromorphic dynamical systems in ℙ2, and laminarity of the dynamical ``Green' current is obtained for a wide class of meromorphic self maps of ℙ2, as well as for all bimeromorphic maps of projective surfaces.
Received: 24 September 2001 / Published online: 10 February 2003
Mathematics Subject Classification (2000): 32U40, 37Fxx, 32H50 相似文献
14.
David Brink Pieter Moree Robert Osburn 《Abhandlungen aus dem Mathematischen Seminar der Universit?t Hamburg》2011,81(2):129-139
In 1966, Shanks and Schmid investigated the asymptotic behavior of the number of positive integers less than or equal to x which are represented by the quadratic form X
2+nY
2. Based on some numerical computations, they observed that the constant occurring in the main term appears to be the largest
for n=2. In this paper, we prove that in fact this constant is unbounded as n runs through positive integers with a fixed number of prime divisors. 相似文献
15.
An undirected graph without isolated vertices is said to be semisymmetric if its full automorphism group acts transitively
on its edge set but not on its vertex set. In this paper, we inquire the existence of connected semisymmetric cubic graphs
of order 16p
2. It is shown that for every odd prime p, there exists a semisymmetric cubic graph of order 16p
2 and its structure is explicitly specified by giving the corresponding voltage rules generating the covering projections. 相似文献
16.
P. Mironescu 《Journal of Mathematical Sciences》2010,170(3):340-355
We describe the structure of the space
Ws,p( \mathbbSn;\mathbbS1 ) {W^{s,p}}\left( {{\mathbb{S}^n};{\mathbb{S}^1}} \right) , where 0 < s < ∞ and 1 ≤ p < ∞. According to the values of s, p, and n, maps in
Ws,p( \mathbbSn;\mathbbS1 ) {W^{s,p}}\left( {{\mathbb{S}^n};{\mathbb{S}^1}} \right) can either be characterised by their phases or by a couple (singular set, phase). 相似文献
17.
Enomoto, Weiner and the first author showed the rigidity of the Clifford torus amongst the class of embedded flat tori in
S
3. In the proof of that result, an estimate of extrinsic diameter of flat tori plays a crucial role. It is reasonable to expect
that the same rigidity holds in the class of immersed flat tori in S
3. In this paper, we give a new method for characterizing immersed flat tori in S
3 with extrinsic diameter π, which is a somewhat similar technique to the proof of the 6-vertex theorem for certain closed plane curves given by the
second author. As an application, we show that the Clifford torus is rigid in the class of immersed flat tori whose mean curvature
functions do not change sign. Recently, the global behaviour of flat surfaces in H
3 and R
3 regarded as wave fronts has been studied. We also give here a formulation of flat tori in S
3 as wave fronts. As an application, we shall exhibit a flat torus as a wave front whose extrinsic diameter is less than π. 相似文献
18.
Multipliers on Vector-valued <Emphasis Type="Italic">L</Emphasis><Superscript>1</Superscript>-spaces for Hypergroups
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In this article, we extend the well known Wendel’s theorem to the context of vector-valued L1-spaces on hypergroups. In this regard, various cases have been studied. 相似文献
19.
This note deals with the orthogonality between sequences of random variables. The main idea of the note is to apply the results
on equidistant systems of points in a Hilbert space to the case of the space L
2(Ω, F, ℙ) of real square integrable random variables. The main result gives a necessary and sufficient condition for a particular
sequence of random variables (elements of which are taken from sets of equidistant elements of L
2(Ω, F, ℙ) to be orthogonal to some other sequence in L
2(Ω, F, ℙ). The result obtained is interesting from the point of view of the time series analysis, since it can be applied to a
class of sequences random variables that exhibit a monotonically increasing variance. An application to ergodic theorem is
also provided. 相似文献
20.
Maria Joiţa 《Czechoslovak Mathematical Journal》2004,54(3):727-737
In this paper the tensor products of Hilbert modules over locally C
*-algebras are defined and their properties are studied. Thus we show that most of the basic properties of the tensor products of Hilbert C
*-modules are also valid in the context of Hilbert modules over locally C
*-algebras. 相似文献