5,432 research outputs found
Analysis of a fractal boundary: the graph of the Knopp function
A usual classification tool to study a fractal interface is the computation
of its fractal dimension. But a recent method developed by Y. Heurteaux and S.
Jaffard proposes to compute either weak and strong accessibility exponents or
local Lp regularity exponents (the so-called p-exponent). These exponents
describe locally the behavior of the interface. We apply this method to the
graph of the Knopp function. The Knopp function itself has everywhere the same
p-exponent. Nevertheless, using the characterization of the maxima and minima
done by B. Dubuc and S. Dubuc, we will compute the p-exponent of the
characteristic function of domain under the graph of F at each point (x,F(x))
and show that p-exponents, weak and strong accessibility exponents change from
point to point. Furthermore we will derive a characterization of the local
extrema of the function according to the values of these exponents
Seamless Infrastructure independent Multi Homed NEMO Handoff Using Effective and Timely IEEE 802.21 MIH triggers
Handoff performance of NEMO BS protocol with existent improvement proposals
is still not sufficient for real time and QoS-sensitive applications and
further optimizations are needed. When dealing with single homed NEMO, handoff
latency and packet loss become irreducible all optimizations included, so that
it is impossible to meet requirements of the above applications. Then, How to
combine the different Fast handoff approaches remains an open research issue
and needs more investigation. In this paper, we propose a new Infrastructure
independent handoff approach combining multihoming and intelligent
Make-Before-Break Handoff. Based on required Handoff time estimation, L2 and L3
handoffs are initiated using effective and timely MIH triggers, reducing so the
anticipation time and increasing the probability of prediction. We extend MIH
services to provide tunnel establishment and switching before link break. Thus,
the handoff is performed in background with no latency and no packet loss while
pingpong scenario is almost avoided. In addition, our proposal saves cost and
power consumption by optimizing the time of simultaneous use of multiple
interfaces. We provide also NS2 simulation experiments identifying suitable
parameter values used for estimation and validating the proposed mode
Relativistic Spectrum of Hydrogen Atom in Space-Time Non-Commutativity
We study space-time non-commutativity applied to the hydrogen atom via the
Seiberg-Witten map and its phenomenological effects. We find that it modifies
the Coulomb potential in the Hamiltonian and add an r-3 part. By calculating
the energies from Dirac equation using perturbation theory, we study the
modifications to the hydrogen spectrum. We find that it removes the degeneracy
with respect to the total angular momentum quantum number and acts like a Lamb
shift. Comparing the results with experimental values from spectroscopy, we get
a new bound for the space-time non-commutative parameter. N.B: In precedent
works (arXiv:0907.1904, arXiv:1003.5732 and arXiv:1006.4590), we have used the
Bopp Shift formulation of non-commutativity but here use it \`a la
Seiberg-Witten in the Relativistic case.Comment: 5 pages, 1 table, ICPTP 2011 Constantine, Algeri
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