共查询到20条相似文献,搜索用时 625 毫秒
1.
D. I. Kovalevskaya 《Problems of Information Transmission》2011,47(1):15-27
A code C in the n-dimensional metric space $
\mathbb{F}_q^n
$
\mathbb{F}_q^n
over the Galois field GF(q) is said to be metrically rigid if any isometry I: C → $
\mathbb{F}_q^n
$
\mathbb{F}_q^n
can be extended to an isometry (automorphism) of $
\mathbb{F}_q^n
$
\mathbb{F}_q^n
. We prove metric rigidity for some classes of codes, including certain classes of equidistant codes and codes corresponding
to one class of affine resolvable designs. 相似文献
2.
V. R. Fatalov 《Problems of Information Transmission》2010,46(2):160-183
Let {ξ
k
}
k=0∞ be a sequence of i.i.d. real-valued random variables, and let g(x) be a continuous positive function. Under rather general conditions, we prove results on sharp asymptotics of the probabilities
$
P\left\{ {\frac{1}
{n}\sum\limits_{k = 0}^{n - 1} {g\left( {\xi _k } \right) < d} } \right\}
$
P\left\{ {\frac{1}
{n}\sum\limits_{k = 0}^{n - 1} {g\left( {\xi _k } \right) < d} } \right\}
, n → ∞, and also of their conditional versions. The results are obtained using a new method developed in the paper, namely,
the Laplace method for sojourn times of discrete-time Markov chains. We consider two examples: standard Gaussian random variables
with g(x) = |x|
p
, p > 0, and exponential random variables with g(x) = x for x ≥ 0. 相似文献
3.
Maxim A. Babenko 《Theory of Computing Systems》2010,46(1):59-79
Let G be an undirected graph and $\mathcal{T}=\{T_{1},\ldots,T_{k}\}Let G be an undirected graph and
T={T1,?,Tk}\mathcal{T}=\{T_{1},\ldots,T_{k}\}
be a collection of disjoint subsets of nodes. Nodes in T
1∪⋅⋅⋅∪T
k
are called terminals, other nodes are called inner. By a
T\mathcal{T}
-path we mean a path P such that P connects terminals from distinct sets in
T\mathcal{T}
and all internal nodes of P are inner. We study the problem of finding a maximum cardinality collection ℘ of
T\mathcal{T}
-paths such that at most two paths in ℘ pass through any node. Our algorithm is purely combinatorial and has the time complexity
O(mn
2), where n and m denote the numbers of nodes and edges in G, respectively. 相似文献
4.
V. R. Fatalov 《Problems of Information Transmission》2010,46(1):62-85
Let w(t) be a standard Wiener process, w(0) = 0, and let η
a
(t) = w(t + a) − w(t), t ≥ 0, be increments of the Wiener process, a > 0. Let Z
a
(t), t ∈ [0, 2a], be a zeromean Gaussian stationary a.s. continuous process with a covariance function of the form E
Z
a
(t)Z
a
(s) = 1/2[a − |t − s|], t, s ∈ [0, 2a]. For 0 < p < ∞, we prove results on sharp asymptotics as ɛ → 0 of the probabilities
$
P\left\{ {\int\limits_0^T {\left| {\eta _a \left( t \right)} \right|^p dt \leqslant \varepsilon ^p } } \right\} for T \leqslant a, P\left\{ {\int\limits_0^T {\left| {Z_a \left( t \right)} \right|^p dt \leqslant \varepsilon ^p } } \right\} for T < 2a
$
P\left\{ {\int\limits_0^T {\left| {\eta _a \left( t \right)} \right|^p dt \leqslant \varepsilon ^p } } \right\} for T \leqslant a, P\left\{ {\int\limits_0^T {\left| {Z_a \left( t \right)} \right|^p dt \leqslant \varepsilon ^p } } \right\} for T < 2a
相似文献
5.
Rahul Tripathi 《Theory of Computing Systems》2010,46(2):193-221
The 1-versus-2 queries problem, which has been extensively studied in computational complexity theory, asks in its generality whether every efficient
algorithm that makes at most 2 queries to a Σ
k
p
-complete language L
k
has an efficient simulation that makes at most 1 query to L
k
. We obtain solutions to this problem for hypotheses weaker than previously considered. We prove that:
6.
CAO FeiLong ZHANG YongQuan & XU ZongBen College of Science China Jiliang University Hangzhou China Institute of Information System Sciences Xi’an Jiaotong University Xi’an 《中国科学F辑(英文版)》2009,52(8):1321-1327
Let SFd and Πψ,n,d = { nj=1bjψ(ωj·x+θj) :bj,θj∈R,ωj∈Rd} be the set of periodic and Lebesgue’s square-integrable functions and the set of feedforward neural network (FNN) functions, respectively. Denote by dist (SF d, Πψ,n,d) the deviation of the set SF d from the set Πψ,n,d. A main purpose of this paper is to estimate the deviation. In particular, based on the Fourier transforms and the theory of approximation, a lower estimation for dist (SFd, Πψ,n,d) is proved. That is, dist(SF d, Πψ,n,d) (nlogC2n)1/2 . T... 相似文献
7.
Mohammad Ali Abam Mark de Berg Mohammad Farshi Joachim Gudmundsson Michiel Smid 《Algorithmica》2011,61(1):207-225
Let (S,d) be a finite metric space, where each element p∈S has a non-negative weight w (p). We study spanners for the set S with respect to the following weighted distance function:
|