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971.
Jean Bertoin 《Probability Theory and Related Fields》1999,114(1):97-121
We investigate the nature of the intersection of two independent regenerative sets. The approach combines Bochners subordination
and potential theory for a pair of Markov processes in duality.
Received: 21 November 1997 / Revised version: 31 August 1998 相似文献
972.
Jean-François Delmas 《Probability Theory and Related Fields》1999,114(4):505-547
We consider a super-Brownian motion X. Its canonical measures can be studied through the path-valued process called the Brownian snake. We obtain the limiting
behavior of the volume of the ɛ-neighborhood for the range of the Brownian snake, and as a consequence we derive the analogous
result for the range of super-Brownian motion and for the support of the integrated super-Brownian excursion. Then we prove
the support of X
t
is capacity-equivalent to [0, 1]2 in ℝd, d≥ 3, and the range of X, as well as the support of the integrated super-Brownian excursion are capacity-equivalent to [0, 1]4 in ℝd, d≥ 5.
Received: 7 April 1998 / Revised version: 2 October 1998 相似文献
973.
We investigate the limiting fluctuations of the order parameter in the Hopfield model of spin glasses and neural networks
with finitely many patterns at the critical temperature 1/β
c
= 1. At the critical temperature, the measure-valued random variables given by the distribution of the appropriately scaled
order parameter under the Gibbs measure converge weakly towards a random measure which is non-Gaussian in the sense that it
is not given by a Dirac measure concentrated in a Gaussian distribution. This remains true in the case of β = β
N
→β
c
= 1 as N→∞ provided β
N
converges to β
c
= 1 fast enough, i.e., at speed ?(1/). The limiting distribution is explicitly given by its (random) density.
Received: 12 May 1998 / Revised version: 14 October 1998 相似文献
974.
J. Müller 《Constructive Approximation》1999,15(4):523-536
Taylor sections S
n
(f) of an entire function f often provide easy computable polynomial approximants of f . However, while the rate of convergence of (S
n
(f))
n
is nearly optimal on circles around the origin, this is no longer true for other plane sets as, for example, real compact
intervals. The aim of this paper is to construct for certain families of (entire) functions sequences of polynomial approximants
which are computable with essentially the same effort as Taylor sections and which have a better rate of convergence on some
parts of the plane. The resulting method may be applied, for example, to (modified) Bessel functions, to confluent hypergeometric
functions, or to parabolic cylinder functions.
October 2, 1997. Date revised: March 12, 1998. Date accepted: April 28, 1998. 相似文献
975.
Superpolynomial Lower Bounds for Monotone Span Programs 总被引:2,自引:0,他引:2
monotone span programs computing explicit functions. The best previous lower bound was by Beimel, Gál, Paterson [7]; our proof exploits a general combinatorial lower bound criterion from that paper. Our lower
bounds are based on an analysis of Paley-type bipartite graphs via Weil's character sum estimates. We prove an lower bound for the size of monotone span programs for the clique problem. Our results give the first superpolynomial lower
bounds for linear secret sharing schemes.
We demonstrate the surprising power of monotone span programs by exhibiting a function computable in this model in linear
size while requiring superpolynomial size monotone circuits and exponential size monotone formulae. We also show that the
perfect matching function can be computed by polynomial size (non-monotone) span programs over arbitrary fields.
Received: August 1, 1996 相似文献
976.
Friedrich Eisenbrand 《Combinatorica》1999,19(2):297-300
A , an integral vector b and some rational vector , decide whether is outside the elementary closure , is NP-complete. This result is achieved by an extension of a result by Caprara and Fischetti.
Received: November 11, 1998 相似文献
977.
O (c+d) steps using constant-size queues, where c is the congestion of the paths in the network, and d is the length of the longest path. The proof, however, used the Lovász Local Lemma and was not constructive. In this paper,
we show how to find such a schedule in time, with probability , for any positive constant β, where is the sum of the lengths of the paths taken by the packets in the network, and m is the number of edges used by some packet in the network. We also show how to parallelize the algorithm so that it runs
in NC. The method that we use to construct the schedules is based on the algorithmic form of the Lovász Local Lemma discovered
by Beck.
Received: July 8, 1996 相似文献
978.
Soojin Cho 《Combinatorica》1999,19(4):589-595
t -designs of the lattice of subspaces of a vector space over a finite field. The lower bound we find gives the tight bound
for many important posets including the Boolean algebra, the lattice of subspaces of a vector space over a finite field, whereas
the idea of the proofs of the main theorems makes it possible to prove that the lower bounds in the main theorems are not
tight for some posets.
Received: November 7, 1995 相似文献
979.
n -vertex edge coloured graphs with multiplicity of Jordan blocks bounded by k can be done in time .
Received: November 29, 1994 相似文献
980.
Toru Tsujishita 《Archive for Mathematical Logic》1999,38(1):1-18
Knowledge modal formulas are interpreted by a universal modal world in the hypersets universe [A]. This remedies the limitation
of the interpretation of knowledge formulas by a tower of modal worlds in the well founded universe [F], where each world
can interpret only a portion of knowledge modal formulas.
Received: 21 August 1995 相似文献