1,714 research outputs found
Radiated Immunity Testing of a Device with an External Wire: Repeatibility of Reverberation Chamber Results and Correlation with Anechoic Chamber Results
We present the experimental radiated immunity results of an electronic device with an external wire obtained in reverberation and anechoic chambers. Repeatability and reproducibility of reverberation chamber measurements are investigated by repeating the test in three reverberation chambers with different characteristics. We show how the current state of the art allows a statistical control of RC measurement repeatability within an industrial installation, and that a statistical correlation with AC results frequency by frequency is possible in particular cases relevant to automotive application
Hamiltonian flows on null curves
The local motion of a null curve in Minkowski 3-space induces an evolution
equation for its Lorentz invariant curvature. Special motions are constructed
whose induced evolution equations are the members of the KdV hierarchy. The
null curves which move under the KdV flow without changing shape are proven to
be the trajectories of a certain particle model on null curves described by a
Lagrangian linear in the curvature. In addition, it is shown that the curvature
of a null curve which evolves by similarities can be computed in terms of the
solutions of the second Painlev\'e equation.Comment: 14 pages, v2: final version; minor changes in the expositio
Binary trees, coproducts, and integrable systems
We provide a unified framework for the treatment of special integrable
systems which we propose to call "generalized mean field systems". Thereby
previous results on integrable classical and quantum systems are generalized.
Following Ballesteros and Ragnisco, the framework consists of a unital algebra
with brackets, a Casimir element, and a coproduct which can be lifted to higher
tensor products. The coupling scheme of the iterated tensor product is encoded
in a binary tree. The theory is exemplified by the case of a spin octahedron.Comment: 15 pages, 6 figures, v2: minor correction in theorem 1, two new
appendices adde
Classical Dynamical Systems from q-algebras:"cluster" variables and explicit solutions
A general procedure to get the explicit solution of the equations of motion
for N-body classical Hamiltonian systems equipped with coalgebra symmetry is
introduced by defining a set of appropriate collective variables which are
based on the iterations of the coproduct map on the generators of the algebra.
In this way several examples of N-body dynamical systems obtained from
q-Poisson algebras are explicitly solved: the q-deformed version of the sl(2)
Calogero-Gaudin system (q-CG), a q-Poincare' Gaudin system and a system of
Ruijsenaars type arising from the same (non co-boundary) q-deformation of the
(1+1) Poincare' algebra. Also, a unified interpretation of all these systems as
different Poisson-Lie dynamics on the same three dimensional solvable Lie group
is given.Comment: 19 Latex pages, No figure
Elementary Darboux transformations and factorization
A general theorem on factorization of matrices with polynomial entries is
proven and it is used to reduce polynomial Darboux matrices to linear ones.
Some new examples of linear Darboux matrices are discussed.Comment: 10 page
Non-coboundary Poisson-Lie structures on the book group
All possible Poisson-Lie (PL) structures on the 3D real Lie group generated
by a dilation and two commuting translations are obtained. Its classification
is fully performed by relating these PL groups with the corresponding Lie
bialgebra structures on the corresponding "book" Lie algebra. By construction,
all these Poisson structures are quadratic Poisson-Hopf algebras for which the
group multiplication is a Poisson map. In contrast to the case of simple Lie
groups, it turns out that most of the PL structures on the book group are
non-coboundary ones. Moreover, from the viewpoint of Poisson dynamics, the most
interesting PL book structures are just some of these non-coboundaries, which
are explicitly analysed. In particular, we show that the two different
q-deformed Poisson versions of the sl(2,R) algebra appear as two distinguished
cases in this classification, as well as the quadratic Poisson structure that
underlies the integrability of a large class of 3D Lotka-Volterra equations.
Finally, the quantization problem for these PL groups is sketched.Comment: 15 pages, revised version, some references adde
Exact Solution of the Quantum Calogero-Gaudin System and of its q-Deformation
A complete set of commuting observables for the Calogero-Gaudin system is
diagonalized, and the explicit form of the corresponding eigenvalues and
eigenfunctions is derived. We use a purely algebraic procedure exploiting the
co-algebra invariance of the model; with the proper technical modifications
this procedure can be applied to the deformed version of the model, which
is then also exactly solved.Comment: 20 pages Late
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