8,401 research outputs found
A renormalization approach for the 2D Anderson model at the band edge: Scaling of the localization volume
We study the localization volumes (participation ratio) of electronic
wave functions in the 2d-Anderson model with diagonal disorder. Using a
renormalization procedure, we show that at the band edges, i.e. for energies
, is inversely proportional to the variance \var of the
site potentials. Using scaling arguments, we show that in the neighborhood of
, scales as V=\var^{-1}g((4-\ve E\ve)/\var) with the scaling
function . Numerical simulations confirm this scaling ansatz
Pushbroom Stereo for High-Speed Navigation in Cluttered Environments
We present a novel stereo vision algorithm that is capable of obstacle
detection on a mobile-CPU processor at 120 frames per second. Our system
performs a subset of standard block-matching stereo processing, searching only
for obstacles at a single depth. By using an onboard IMU and state-estimator,
we can recover the position of obstacles at all other depths, building and
updating a full depth-map at framerate.
Here, we describe both the algorithm and our implementation on a high-speed,
small UAV, flying at over 20 MPH (9 m/s) close to obstacles. The system
requires no external sensing or computation and is, to the best of our
knowledge, the first high-framerate stereo detection system running onboard a
small UAV
Pore opening effects and transport diffusion in the Knudsen regime in comparison to self- (or tracer-) diffusion
We study molecular diffusion in linear nanopores with different types of
roughness in the so-called Knudsen regime. Knudsen diffusion represents the
limiting case of molecular diffusion in pores, where mutual encounters of the
molecules within the free pore space may be neglected and the time of flight
between subsequent collisions with the pore walls significantly exceeds the
interaction time between the pore wall and the molecules. We present an
extension of a commonly used procedure to calculate transport diffusion
coefficients. Our results show that using this extension, the coefficients of
self- and transport diffusion in the Knudsen regime are equal for all regarded
systems, which improves previous literature data.Comment: 5 pages, 7 figure
Electron muon identification by atmospheric shower and electron beam in a new concept of an EAS detector
We present results demonstrating the time resolution and /e separation
capabilities with a new concept of an EAS detector capable for measurements of
cosmic rays arriving with large zenith angles. This kind of detector has been
designed to be a part of a large area (several square kilometers) surface array
designed to measure Ultra High Energy (10-200 PeV) neutrinos using the
Earth-skimming technique. A criteria to identify electron-gammas is also shown
and the particle identification capability is tested by measurements in
coincidence with the KASKADE-GRANDE experiment in Karlsruhe, Germany.Comment: accepted by Astrophysical Journal on January 12 2015, 16 pages 3
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