Accelerating Radio Wave Propagation Algorithms by Implementation on Graphics Hardware

Radio wave propagation prediction is a fundamental prerequisite for planning, analysis and optimization of radio networks. For instance coverage analysis, interference estimation or channel and power allocation all rely on propagation predictions. In wireless communication networks optimal antenna sites are determined by either conducting a serie

Dark Matter Disc Enhanced Neutrino Fluxes from the Sun and Earth

As disc galaxies form in a hierarchical cosmology, massive merging satellites are preferentially dragged towards the disc plane. The material accreted from these satellites forms a dark matter disc that contributes 0.25 - 1.5 times the non-rotating halo density at the solar position. Here, we show the importance of the dark disc for indirect dark matter detection in neutrino telescopes. Previous predictions of the neutrino flux from WIMP annihilation in the Earth and the Sun have assumed that Galactic dark matter is spherically distributed with a Gaussian velocity distribution, the standard halo model. Although the dark disc has a local density comparable to the dark halo, its higher phase space density at low velocities greatly enhances capture rates in the Sun and Earth. For typical dark disc properties, the resulting muon flux from the Earth is increased by three orders of magnitude over the SHM, while for the Sun the increase is an order of magnitude. This significantly increases the sensitivity of neutrino telescopes to fix or constrain parameters in WIMP models. The flux from the Earth is extremely sensitive to the detailed properties of the dark disc, while the flux from the Sun is more robust. The enhancement of the muon flux from the dark disc puts the search for WIMP annihilation in the Earth on the same level as the Sun for WIMP masses < 100 GeV.Comment: 7 pages, 4 figures, added a short paragraph to the discussion section, conclusions unchanged, published versio

An Evaluation of Open Source Physics Engines for Use in Virtual Reality Assembly Simulations

We present a comparison of five freely available physics engines with specific focus on robotic assembly simulation in virtual reality (VR) environments. The aim was to evaluate the engines with generic settings and minimum parameter tweaking. Our benchmarks consider the minimum collision detection time for a large number of objects, restitution characteristics, as well as constraint reliability and body inter-penetration. A further benchmark tests the simulation of a screw and nut mechanism made of rigid-bodies only, without any analytic approximation. Our results show large deviations across the tested engines and reveal benefits and disadvantages that help in selecting the appropriate physics engine for assembly simulations in VR