160,285 research outputs found
Diffusion multi-rate LMS algorithm for acoustic sensor networks
In this paper, we present a diffusion multi-rate least-mean-square (LMS)
algorithm, named DMLMS, which is an effective solution for distributed
estimation when two or more observation sequences are available with different
sampling rates. Then, we focus on a more practical application in the wireless
acoustic sensor networks (ASN). The filtered-x LMS (FxLMS) algorithm is
extended to the distributed multi-rate system and it introduces collaboration
between nodes following a diffusion strategy. Simulation results show that the
effectiveness of the proposed algorithms
Frozen Gaussian approximation for general linear strictly hyperbolic system: formulation and Eulerian methods
The frozen Gaussian approximation, proposed in [Lu and Yang, [15]], is an
efficient computational tool for high frequency wave propagation. We continue
in this paper the development of frozen Gaussian approximation. The frozen
Gaussian approximation is extended to general linear strictly hyperbolic
systems. Eulerian methods based on frozen Gaussian approximation are developed
to overcome the divergence problem of Lagrangian methods. The proposed Eulerian
methods can also be used for the Herman-Kluk propagator in quantum mechanics.
Numerical examples verify the performance of the proposed methods
Hardy-Sobolev-Maz'ya inequalities for higher order derivatives on half spaces
By using, among other things, the Fourier analysis techniques on hyperbolic
and symmetric spaces, we establish the Hardy-Sobolev-Maz'ya inequalities for
higher order derivatives on half spaces. The proof relies on a
Hardy-Littlewood-Sobolev inequality on hyperbolic spaces which is of its
independent interest. We also give an alternative proof of Benguria, Frank and
Loss' work concerning the sharp constant in the Hardy-Sobolev-Maz'ya inequality
in the three dimensional upper half space. Finally, we show the sharp constant
in the Hardy-Sobolev-Maz'ya inequality for bi-Laplacian in the upper half space
of dimension five coincides with the Sobolev constant.Comment: 32 page
The electromagnetic form factors of hyperon in
We study the electromagnetic form factors of hyperon in the
timelike region using the recent experimental data in the exclusive production
of pair in electron-position annihilation. We present a
pQCD inspired parametrization of and with only two
parameters, and we consider a suppression mechanism of the electric form factor
compared to the magnetic form factor . The parameters are
determined through fitting our parametrization to the effective form factor
data in the reaction . Except the
threshold region, our parametrization can reproduce satisfactorily the known
behavior of the existing data from the BarBar, DM2 and BESIII Collaborations.
We also predict the double spin polarization observables , and
in .Comment: 5 pages, 3 figure
Phase Space Sketching for Crystal Image Analysis based on Synchrosqueezed Transforms
Recent developments of imaging techniques enable researchers to visualize
materials at the atomic resolution to better understand the microscopic
structures of materials. This paper aims at automatic and quantitative
characterization of potentially complicated microscopic crystal images,
providing feedback to tweak theories and improve synthesis in materials
science. As such, an efficient phase-space sketching method is proposed to
encode microscopic crystal images in a translation, rotation, illumination, and
scale invariant representation, which is also stable with respect to small
deformations. Based on the phase-space sketching, we generalize our previous
analysis framework for crystal images with simple structures to those with
complicated geometry
Analytic Constructions of General n-Qubit Controlled Gates
In this Letter, we present two analytic expressions that most generally
simulate -qubit controlled- gates with standard one-qubit gates and CNOT
gates using exponential and polynomial complexity respectively. Explicit
circuits and general expressions of decomposition are derived. The exact
numbers of basic operations in these two schemes are given using gate counting
technique.Comment: 4 pages 7 figure
A sharp Trudinger-Moser inequality on any bounded and convex planar domain
Wang and Ye conjectured in [22]:
Let be a regular, bounded and convex domain in .
There exists a finite constant such that where
and .}
The main purpose of this paper is to confirm that this conjecture indeed
holds for any bounded and convex domain in via the Riemann
mapping theorem (the smoothness of the boundary of the domain is thus
irrelevant).
We also give a rearrangement-free argument for the following Trudinger-Moser
inequality on the hyperbolic space
: by using the method
employed earlier by Lam and the first author [9, 10], where
denotes the closure of with respect to the norm
Using this
strengthened Trudinger-Moser inequality, we also give a simpler proof of the
Hardy-Moser-Trudinger inequality obtained by Wang and Ye [22]
Distributed economic control of dynamically coupled networks
This paper investigates the synthesis of distributed economic control
algorithms under which dynamically coupled physical systems are regulated to a
variational equilibrium of a constrained convex game. We study two
complementary cases: (i) each subsystem is linear and controllable; and (ii)
each subsystem is nonlinear and in the strict-feedback form. The convergence of
the proposed algorithms is guaranteed using Lyapunov analysis. Their
performance is verified by two case studies on a multi-zone building
temperature regulation problem and an optimal power flow problem, respectively.Comment: 14 pages, 4 figures, journa
SL(n,R)-Toda Black Holes
We consider D-dimensional Einstein gravity coupled to (n-1) U(1) vector
fields and (n-2) dilatonic scalars. We find that for some appropriate
exponential dilaton couplings of the field strengths, the equations of motion
for the static charged ansatz can be reduced to a set of one-dimensional
SL(n,R) Toda equations. This allows us to obtain a general class of explicit
black holes with mass and (n-1) independent charges. The near-horizon geometry
in the extremal limit is AdS_2 x S^{D-2}. The n=2 case gives the
Reissner-Nordstrom solution, and the n=3 example includes the Kaluza-Klein
dyon. We study the global structure and the black hole thermodynamics and
obtain the universal entropy product formula. We also discuss the
characteristics of extremal multi-charge black holes that have positive, zero
or negative binding energies.Comment: Latex, 20 page
Green's functions of Paneitz and GJMS operators on hyperbolic spaces and sharp Hardy-Sobolev-Maz'ya inequalities on half spaces
Using the Fourier analysis techniques on hyperbolic spaces and Green's
function estimates, we confirm in this paper the conjecture given by the same
authors in [43]. Namely, we prove that the sharp constant in the
-th order Hardy-Sobolev-Maz'ya inequality in the upper half
space of dimension coincides with the best -th order Sobolev
constant when is odd and (See Theorem 1.6). We will also establish
a lower bound of the coefficient of the Hardy term for the th order
Hardy-Sobolev-Maz'ya inequality in upper half space in the remaining cases of
dimension and -th order derivatives (see Theorem 1.7). Precise
expressions and optimal bounds for Green's functions of the operator on the hyperbolic space
and operators of the product form are given, where
is the spectral gap for the Laplacian
on . Finally, we give the precise
expression and optimal pointwise bound of Green's function of the Paneitz and
GJMS operators on hyperbolic space, which are of their independent interest
(see Theorem 1.10).Comment: 33 page
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