共查询到20条相似文献,搜索用时 31 毫秒
1.
In this paper, we study cyclic codes over the rings Z
2 + uZ
2 and Z
2 + uZ
2 + u
2
Z
2 . We find a set of generators for these codes. The rank, the dual, and the Hamming distance of these codes are studied as
well. Examples of cyclic codes of various lengths are also studied.
相似文献
2.
We establish uniqueness in the inverse conductivity problem for conductivities which have 3/2 derivatives in Lp, p > 2n. Our results are in dimensions three and higher. 相似文献
3.
Graham R. Brightwell 《Order》1989,5(4):369-380
A well-known conjecture of Fredman is that, for every finite partially ordered set (X, <) which is not a chain, there is a pair of elements x, y such that P(x, the proportion of linear extensions of (X, <) with x below y, lies between 1/3 and 2/3. In this paper, we prove the conjecture in the special case when (X, <) is a semiorder. A property we call 2-separation appears to be crucial, and we classify all locally finite 2-separated posets of bounded width. 相似文献
4.
For every integer m ≥ 3 and every integer c, let r(m, c) be the least integer, if it exists, such that for every 2-coloring of the set {1, 2, …, r(m, c)} there exists a monochromatic solution to the equation
The values of r(m, c) were previously known for all values of m and all nonnegative values of c. In this paper, exact values of r(m, c) are found for all values of m and all values of c such that − m + 2 < c < 0 or c < − (m − 1)(m − 2). Upper and lower bounds are given for the remaining values of c. 相似文献
5.
Jianqin Zhou 《Designs, Codes and Cryptography》2011,58(3):279-296
In this paper, we first optimize the structure of the Wei–Xiao–Chen algorithm for the linear complexity of sequences over GF(q) with period N = 2p
n
, where p and q are odd primes, and q is a primitive root modulo p
2. The second, an union cost is proposed, so that an efficient algorithm for computing the k-error linear complexity of a sequence with period 2p
n
over GF(q) is derived, where p and q are odd primes, and q is a primitive root modulo p
2. The third, we give a validity of the proposed algorithm, and also prove that there exists an error sequence e
N
, where the Hamming weight of e
N
is not greater than k, such that the linear complexity of (s + e)
N
reaches the k-error linear complexity c. We also present a numerical example to illustrate the algorithm. Finally, we present the minimum value k for which the k-error linear complexity is strictly less than the linear complexity. 相似文献
6.
The matrix least squares (LS) problem minx ||AXB^T--T||F is trivial and its solution can be simply formulated in terms of the generalized inverse of A and B. Its generalized problem minx1,x2 ||A1X1B1^T + A2X2B2^T - T||F can also be regarded as the constrained LS problem minx=diag(x1,x2) ||AXB^T -T||F with A = [A1, A2] and B = [B1, B2]. The authors transform T to T such that min x1,x2 ||A1X1B1^T+A2X2B2^T -T||F is equivalent to min x=diag(x1 ,x2) ||AXB^T - T||F whose solutions are included in the solution set of unconstrained problem minx ||AXB^T - T||F. So the general solutions of min x1,x2 ||A1X1B^T + A2X2B2^T -T||F are reconstructed by selecting the parameter matrix in that of minx ||AXB^T - T||F. 相似文献
7.
R. Kemp 《Discrete Mathematics》1982,40(2-3)
Let S be the set of all palindromes over Σ*. It is well known, that the language S2 is an ultralinear, inherently ambiguous context-free language. In this paper we derive an explicit expression for the number of words of length n in S2. Furthermore, we show, that for card(Σ) > 1 the asymptotical density of the language S2 is zero and that, in the average, each word w of length n in S2 has exactly one factorization into two palindromes for large n; the variance is zero for large n. Finally, we compute an expression for the structure-generating- function T(S2;z) of the language S2; it remains the open problem, if T(S2;z) is a transcendental or an algebraic function. 相似文献
8.
We show that any embedding of the level k diamond graph of
Newman and Rabinovich [NR] into Lp, 1 < p 2, requires distortion at
least
. An immediate corollary is that there exist arbitrarily
large n-point sets
such that any D-embedding of X into
requires
. This gives a simple proof of a recent result of Brinkman
and Charikar [BrC] which settles the long standing question of whether
there is an L1 analogue of the Johnson-Lindenstrauss dimension reduction
lemma [JL]. 相似文献
9.
In this paper a method for the resolution of the differential equation of the Jacobi vector fields in the manifold V
1 = Sp(2)/SU(2) is exposed. These results are applied to determine areas and volumes of geodesic spheres and balls. 相似文献
10.
Xu Mingchun 《中国科学A辑(英文版)》2006,49(9):1158-1164
In this paper the author has solved a problem of Abe and liyori for the finite simple groups 2
F
4(q) and 2
F
4(2)′. 相似文献
11.
M. R. DARAFSHEH 《数学学报(英文版)》2008,24(7):1117-1126
The author will prove that the group ^2Dp(3) can be uniquely determined by its order components, where p ≠ 2^m + 1 is a prime number, p ≥ 5. More precisely, if OC(G) denotes the set of order components of G, we will prove OC(G) = OC(^2Dp(3)) if and only if G is isomorphic to ^2Dp(3). A main consequence of our result is the validity of Thompson's conjecture for the groups under consideration. 相似文献
12.
Let 0<p<∞ and 0α<β2π. We prove that for n1 and trigonometric polynomials sn of degree n, we have
cnp ∫βα |sn(θ)|p dθ, where c is independent of α, β, n, sn. The essential feature is the uniformity in [α,β] of the estimate and the fact that as [α,β] approaches [0,2π], we recover the Lp Markov inequality. The result may be viewed as the complete Lp form of Videnskii's inequalities, improving earlier work of the second author. 相似文献
Full-size image
13.
V. Chernousov 《Mathematische Annalen》2003,326(2):297-330
We prove that for a simple simply connected quasi-split group of type 3,6
D
4
,E
6
,E
7
defined over a perfect field F of characteristic ≠=2,3 the Rost invariant has trivial kernel. In certain cases we give a formula for the Rost invariant.
It follows immediately from the result above that if cd F≤2 (resp. vcd F≤2) then Serre's Conjecture II (resp. the Hasse principle) holds for such a group. For a (C
2
)-field, in particular ℂ(x,y), we prove the stronger result that Serre's Conjecture II holds for all (not necessary quasi-split) exceptional groups of
type 3,6
D
4
,E
6
,E
7
.
Received: 27 March 2002 /
Published online: 28 March 2003
The author gratefully acknowledge the support of TMR ERB FMRX CT-97-0107 and Forschungsinstitut für Mathematik, ETH in Zürich 相似文献
14.
We give a construction of a family of CAP representations of the exceptional group G
2, whose existence is predicted by Arthur’s conjecture. These are constructed by lifting certain cuspidal representations of
PGS
p6. To show that the lifting is non-zero, we establish a Rankin-Selberg integral for the degree 8 Spin L-function of these cuspidal representations of PGS
p6. 相似文献
15.
Alexander Nenashev 《K-Theory》2005,34(3):219-232
We interpret the Steinberg symbols xi,j(a) as homotopies contracting the elementary matrices ei,j(a), the latters being represented by certain arcs in a simplicial model of the K-theory. We further prove the Steinberg relations for these homotopies. This provides an explicit map from K2 of a ring, defined classically as ker(St(R) → GL(R)), to π2 of the G-construction assigned to R. Though the two groups are known to be isomorphic, a certain work is to be done to prove that this explicit map is an isomorphism.
Mathematics Subject Classification 1991: Primary 19B99, 19D99; secondary 18E10, 18F25. 相似文献
16.
Algebraic K-Theory and the Conjectural Leibniz K-Theory 总被引:1,自引:0,他引:1
Jean-Louis Loday 《K-Theory》2003,30(2):105-127
The analogy between algebraic K-theory and cyclic homology is used to build a program aiming at understanding the algebraic K-theory of fields and the periodicity phenomena in algebraic K-theory. In particular, we conjecture the existence of a Leibniz K-theory which would play the role of Hochschild homology. We propose a motivated presentation for the Leibniz K
2-group ofa field. 相似文献
17.
Mao Hua LE 《数学学报(英文版)》2008,24(6):917-924
Let a, b and c be fixed coprime positive integers. In this paper we prove that if a^2 + b^2 = c^3 and b is an odd prime, then the equation a^x + b^y = c^z has only the positive integer solution (x, y, z) = (2,2,3). 相似文献
18.
We provide generalizations of two of Euler’s classical transformation formulas for the Gauss hypergeometric function extended
to the case of the generalized hypergeometric function
r+2
F
r+1(x) when there are additional numeratorial and denominatorial parameters differing by unity. The method employed to deduce the
latter is also implemented to obtain a Kummer-type transformation formula for
r+1
F
r+1 (x) that was recently derived in a different way. 相似文献
19.
20.
We obtain the exact convergence rate of the stationary distribution (K) of the embedded Markov chain in GI/M/c/K queue to the stationary distribution of the embedded Markov chain in GI/M/c queue as K. Similar result for the time-stationary distributions of queue size is also included. These generalize Choi and Kim's results of the case c=1 by nontrivial ways. Our results also strengthen the Simonot's results [5]. 相似文献