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1.
Remco Duits Michael Felsberg Gösta Granlund Bart ter Haar Romeny 《International Journal of Computer Vision》2007,72(1):79-102
Inspired by the early visual system of many mammalians we consider the construction of-and reconstruction from- an orientation
score
as a local orientation representation of an image,
. The mapping
is a wavelet transform
corresponding to a reducible representation of the Euclidean motion group onto
and oriented wavelet
. This wavelet transform is a special case of a recently developed generalization of the standard wavelet theory and has the
practical advantage over the usual wavelet approaches in image analysis (constructed by irreducible representations of the
similitude group) that it allows a stable reconstruction from one (single scale) orientation score. Since our wavelet transform
is a unitary mapping with stable inverse, we directly relate operations on orientation scores to operations on images in a
robust manner.
Furthermore, by geometrical examination of the Euclidean motion group
, which is the domain of our orientation scores, we deduce that an operator Φ on orientation scores must be left invariant
to ensure that the corresponding operator
on images is Euclidean invariant. As an example we consider all linear second order left invariant evolutions on orientation
scores corresponding to stochastic processes on G. As an application we detect elongated structures in (medical) images and automatically close the gaps between them.
Finally, we consider robust orientation estimates by means of channel representations, where we combine robust orientation
estimation and learning of wavelets resulting in an auto-associative processing of orientation features. Here linear averaging
of the channel representation is equivalent to robust orientation estimation and an adaptation of the wavelet to the statistics
of the considered image class leads to an auto-associative behavior of the system.
The Netherlands Organization for Scientific Research is gratefully acknowledged for financial support. This work has been
supported by EC Grant IST-2003-004176 COSPAL. 相似文献
2.
3.
Agent Communication Languages (ACLs) have been developed to provide a way for agents to communicate with each other supporting
cooperation in Multi-Agent Systems (MAS). In the past few years many ACLs have been proposed for MAS and new standards are
emerging such as the ACL developed by the Foundation for Intelligent Physical Agents (FIPA). Despite these efforts, an important
issue in the research on ACLs is still open and concerns how these languages should deal with failures of agents in asynchronous MAS. The Fault Tolerant Agent Communication Language (
-
) presented in this paper addresses this issue dealing with crash failures of agents.
-
provides high-level communication primitives which support a fault-tolerant anonymous interaction protocol designed for open
MAS. We present a formal semantics for
-
and a formal specification of the underlying agent architecture. This formal framework allows us to prove that the ACL satisfies
a set of well defined knowledge-level programming requirements. To illustrate the language features we show how
-
can be effectively used to write high-level executable specifications of fault tolerant protocols, such as the Contract Net
one. 相似文献
4.
The Sum of D Small-Bias Generators Fools Polynomials of Degree D 总被引:1,自引:1,他引:0
Emanuele Viola 《Computational Complexity》2009,18(2):209-217
5.
6.
R. F. Streater 《Open Systems & Information Dynamics》2004,11(4):359-375
Let H0 be a selfadjoint operator such that Tr
is of trace class for some
, and let
denote the set of ε-bounded forms, i.e.,
for some
0 $$" align="middle" border="0">
. Let χ := Span
. Let
denote the underlying set of the quantum information manifold of states of the form
. We show that if Tr
,
Presented at the 36th Symposium on Mathematical Physics, ‘Open Systems & Quantum Information’, Toruń, Poland, June 9-12, 2004. 相似文献
1. | the map Φ,
| |
2. | The Orlicz space defined by Φ is the tangent space of at ρ0; its affine structure is defined by the (+1)-connection of Amari | |
3. | The subset of a ‘hood of ρ0, consisting of p-nearby states (those obeying for some 1$$" align="middle" border="0"> ) admits a flat affine connection known as the (-1) connection, and the span of this set is part of the cotangent space of | |
4. | These dual structures extend to the completions in the Luxemburg norms. |
7.
On Defining Integers And Proving Arithmetic Circuit Lower Bounds 总被引:1,自引:1,他引:0
Peter Bürgisser 《Computational Complexity》2009,18(1):81-103
8.
9.
Abstract We obtain a multivariate extension of a classical result of Schoenberg on cardinal spline interpolation. Specifically, we
prove the existence of a unique function in
, polyharmonic of order p on each strip
,
, and periodic in its last n variables, whose restriction to the parallel hyperplanes
,
, coincides with a prescribed sequence of n-variate periodic data functions satisfying a growth condition in
. The constructive proof is based on separation of variables and on Micchelli’s theory of univariate cardinal
-splines.
Keywords: cardinal
-splines, polyharmonic functions, multivariable interpolation
Mathematics Subject Classification (2000): 41A05, 41A15, 41A63 相似文献
10.
Any given n×n matrix A is shown to be a restriction, to the A-invariant subspace, of a nonnegative N×N matrix B of spectral radius (B) arbitrarily close to (A). A difference inclusion
, where
is a compact set of matrices, is asymptotically stable if and only if
can be extended to a set
of nonnegative matrices B with
or
. Similar results are derived for differential inclusions. 相似文献
11.
12.
We construct a linear interval system Ax = b with a 4 × 4 interval matrix whose all proper interval coefficients (there are also some noninterval ones) are of the form [–, ]. It is proved that for each > 0, the interval hull
and interval hull of the midpoint preconditioned system
satisfy
and
, hence midpoint preconditioning produces a 100% overestimation of
independently of in this case. The example was obtained as a result of an extensive MATLAB search. 相似文献
14.
15.
Towards proving strong direct product theorems 总被引:1,自引:1,他引:0
Ronen Shaltiel 《Computational Complexity》2003,12(1-2):1-22
A fundamental question of complexity theory is the direct
product question. A famous example is Yaos XOR-lemma, in which one
assumes that some function f is hard on average for small circuits (meaning
that every circuit of some fixed size s which attempts to compute f
is wrong on a non-negligible fraction of the inputs) and concludes that
every circuit of size s
only has a small advantage over guessing randomly
when computing
on independently chosen
. All known proofs of this lemma have the property
that
s < s
. In words, the circuit which attempts to compute
is smaller than the circuit which attempts to compute f on a single input!
This paper addresses the issue of proving strong direct product assertions,
that is, ones in which
and is in particular larger than s.
We study the question of proving strong direct product question for decision trees and communication protocols. 相似文献
16.
17.
Coupling and self-stabilization 总被引:1,自引:0,他引:1
A randomized self-stabilizing algorithm
is an algorithm that, whatever the initial configuration is, reaches a set
of М legal configurations} in finite time with probability 1. The proof of convergence towards
is generally done by exhibiting a potential function
, which measures the “vertical” distance of any configuration to
, such that
decreases with non-null probability at each step of
. We propose here a method, based on the notion of coupling, which makes use of a “horizontal” distance
between any pair of configurations, such that
decreases in expectation at each step of
. In contrast with classical methods, our coupling method does not require the knowledge of
. In addition to the proof of convergence, the method allows us to assess the convergence rate according to two different
measures. Proofs produced by the method are often simpler or give better upper bounds than their classical counterparts, as
examplified here on Herman's mutual exclusion and Iterated Prisoner's Dilemma algorithms in the case of cyclic graphs. 相似文献
18.
The generalized Zakharov system (ZS) couples a dispersive field E (scalar or vectorial) and
nondispersive fields
with a propagating speed of
. In this paper, we extend our one-dimensional time-splitting spectral method (TSSP) for the generalized ZS into higher dimension.
A main new idea is to reformulate the multi-dimensional wave equations for the nondispersive fields into a first-order system
using a change of variable defined in the Fourier space. The proposed scheme TSSP is unconditionally stable, second-order
in time and spectrally accurate in space. Moreover, in the subsonic regime, it allows numerical capturing of the subsonic
limit without resolving the small parameters
. Numerical examples confirm these properties of this method 相似文献
19.
I. V. Gaishun 《Automation and Remote Control》2002,63(11):1717-1723
A class of two-parameter discrete systems defined on the ring
of class of residues of integers
modulo m is studied. All solutions are shown to be periodic, stability conditions (equality of solutions to zero, beginning from a certain instant) and a controllability condition are formulated. Controllability is shown to guarantee stabilizability. 相似文献
20.
Let
be a finite field withq elements and
a rational function over
. No polynomial-time deterministic algorithm is known for the problem of deciding whetherf induces a permutation on
. The problem has been shown to be in co-R
co-NP, and in this paper we prove that it is inR
NP and hence inZPP, and it is deterministic polynomial-time reducible to the problem of factoring univariate polynomials over
. Besides the problem of recognizing prime numbers, it seems to be the only natural decision problem inZPP unknown to be inP. A deterministic test and a simple probabilistic test for permutation functions are also presented. 相似文献