1,060 research outputs found
Renormalization Group Evolution of Flavour Invariants
The fermion spectrum in the Standard Model (SM) exhibits hierarchical
structures between the eigenvalues of the Yukawa matrices which determine the
fermion masses, as well as certain hierarchical patterns in the mixing matrix
that describes weak transitions between different fermion generations. A
basis-independent description of the SM flavour structure can be given in terms
of a complete set of flavour invariants. In this paper, we construct a
convenient set of such invariants, and discuss the general form of the
renormalization-group equations. We also discuss the simplifications that arise
from exploiting hierarchies in Yukwawa couplings and mixings which are present
in the SM or its minimal-flavour violating extensions.Comment: 27 pages, 3 figure
Andreas Zeising: Radiokunstgeschichte: Bildende Kunst und Kunstvermittlung im frühen Rundfunk der 1920er bis 1940er Jahre
Improved Fourier Mellin Invariant for Robust Rotation Estimation with Omni-cameras
Spectral methods such as the improved Fourier Mellin Invariant (iFMI)
transform have proved faster, more robust and accurate than feature based
methods on image registration. However, iFMI is restricted to work only when
the camera moves in 2D space and has not been applied on omni-cameras images so
far. In this work, we extend the iFMI method and apply a motion model to
estimate an omni-camera's pose when it moves in 3D space. This is particularly
useful in field robotics applications to get a rapid and comprehensive view of
unstructured environments, and to estimate robustly the robot pose. In the
experiment section, we compared the extended iFMI method against ORB and AKAZE
feature based approaches on three datasets showing different type of
environments: office, lawn and urban scenery (MPI-omni dataset). The results
show that our method boosts the accuracy of the robot pose estimation two to
four times with respect to the feature registration techniques, while offering
lower processing times. Furthermore, the iFMI approach presents the best
performance against motion blur typically present in mobile robotics.Comment: 5 pages, 4 figures, 1 tabl
Chemische Triebkräfte : Von der Verbrennung zum Herzschlag
Was hat eine einfache chemische Verbrennung mit dem Herzschlag zu tun? Diese Frage soll im Rahmen einer physikalisch-chemischen Experimentalvorlesung beantwortet werden. Dabei fügen sich anscheinend weit voneinander entfernte Phänomene in ein klar strukturiertes Bild. Es wird deutlich, dass der menschliche Körper aus thermodynamischer Sicht eine biologische \u27Wärmekraftmaschine\u27 ist, deren Wirkungsgrad höher als der Wirkungsgrad mechanische Wärmekraftmaschinen (\u27Dampfmaschinen\u27). Spröde anmutende thermodynamische Sätze füllen sich mit Leben - die Begriffe \u27Energie, Wärme, Entropie\u27 werden anschaulich. Anhand einfacher Demonstrationsexperimente wird ein Bogen über 250 Jahre Forschung im Bereich der chemischen Energiewandlung gespannt
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