229 research outputs found
On the Existence of a Kazantzis-Kravaris/Luenberger Observer
We state sufficient conditions for the existence, on a given open set, of the
extension, to nonlinear systems, of the Luenberger observer as it has been
proposed by Kazantzis and Kravaris. We prove it is sufficient to choose the
dimension of the system, giving the observer, less than or equal to 2 + twice
the dimension of the state to be observed. We show that it is sufficient to
know only an approximation of the solution of a PDE, needed for the
implementation. We establish a link with high gain observers. Finally we extend
our results to systems satisfying an unboundedness observability property
Ionisation by quantised electromagnetic fields: The photoelectric effect
In this paper we explain the photoelectric effect in a variant of the
standard model of non relativistic quantum electrodynamics, which is in some
aspects more closely related to the physical picture, than the one studied in
[BKZ]: Now we can apply our results to an electron with more than one bound
state and to a larger class of electron-photon interactions. We will specify a
situation, where ionisation probability in second order is a weighted sum of
single photon terms. Furthermore we will see, that Einstein's equality
for the maximal kinetic energy of
the electron, energy of the photon and ionisation gap
is the crucial condition for these single photon terms to be nonzero.Comment: 59 pages, LATEX2
Electrically and Magnetically Charged States and Particles in the 2+1-Dimensional Z_N-Higgs Gauge Model
Electrically as well as magnetically charged states are constructed in the
2+1-dimensional Euclidean Z_N-Higgs lattice gauge model, the former following
ideas of Fredenhagen and Marcu and the latter using duality transformations on
the algebra of observables. The existence of electrically and of magnetically
charged particles is also established. With this work we prepare the ground for
the constructive study of anyonic statistics of multiparticle scattering states
of electrically and magnetically charged particles in this model (work in
progress).Comment: 57 pages, Sfb 288 Preprint No. 109. To appear in Commun. Math. Phys.
About the file: This is a uuencoded, "gzip-ed" postscript file. It is about
300kB large. The original ps file is about 700kB large. All figures are
included. The LaTeX sources ou even hard copies can be required to the
authors at [email protected] or Freie Universitaet Berlin.
Institut fuer Theoretische Physik. Arnimallee 14. Berlin 14195 German
The relationship of interpersonal perception to effectiveness in basketball teams / report No. 3
Caption title."Study performed under Contract N6ori-07135 with the Office of Naval Research"--Cover.Includes bibliographical references (leaf 23
An Independent and Coordinated Criterion for Kinematic Aircraft Maneuvers
This paper proposes a mathematical definition of an aircraft-separation criterion for kinematic-based horizontal maneuvers. It has been formally proved that kinematic maneu- vers that satisfy the new criterion are independent and coordinated for repulsiveness, i.e., the distance at closest point of approach increases whether one or both aircraft maneuver according to the criterion. The proposed criterion is currently used in NASA's Airborne Coordinated Resolution and Detection (ACCoRD) set of tools for the design and analysis of separation assurance systems
Discrete radar ambiguity problems
In this paper, we pursue the study of the radar ambiguity problem started in
\cite{Ja,GJP}. More precisely, for a given function we ask for all
functions (called \emph{ambiguity partners}) such that the ambiguity
functions of and have same modulus. In some cases, may be given by
some elementary transformation of and is then called a \emph{trivial
partner} of otherwise we call it a \emph{strange partner}. Our focus here
is on two discrete versions of the problem. For the first one, we restrict the
problem to functions of the Hermite class, , thus
reducing it to an algebraic problem on polynomials. Up to some mild restriction
satisfied by quasi-all and almost-all polynomials, we show that such a function
has only trivial partners. The second discretization, restricting the problem
to pulse type signals, reduces to a combinatorial problem on matrices of a
special form. We then exploit this to obtain new examples of functions that
have only trivial partners. In particular, we show that most pulse type signals
have only trivial partners. Finally, we clarify the notion of \emph{trivial
partner}, showing that most previous counterexamples are still trivial in some
restricted sense
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