54 research outputs found
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
ΠΠ»ΠΈΡΠ½ΠΈΠ΅ ΠΏΡΠΈΠΌΠ΅ΡΠ΅ΠΉ Π½Π° Π²ΠΎΠ·Π±ΡΠΆΠ΄Π΅Π½ΠΈΠ΅ ΠΈ ΡΠ°Π·Π²ΠΈΡΠΈΠ΅ Π΄Π΅ΡΠΎΠ½Π°ΡΠΈΠΈ Π² Π½Π΅ΠΊΠΎΡΠΎΡΡΡ Π½Π΅ΠΎΡΠ³Π°Π½ΠΈΡΠ΅ΡΠΊΠΈΡ ΠΈΠ½ΠΈΡΠΈΠΈΡΡΡΡΠΈΡ Π°Π·ΠΈΠ΄Π°Ρ
ΠΠΎΡΠ²Π΅Π½Π½ΠΎΠ΅ ΠΎΠΏΡΠ΅Π΄Π΅Π»Π΅Π½ΠΈΠ΅ Ρ ΡΠΎΠΌΠ° (III) ΠΌΠ΅ΡΠΎΠ΄ΠΎΠΌ ΠΏΠΎΠ»ΡΡΠΎΠ³ΡΠ°ΡΠΈΠΈ Ρ Π½Π°ΠΊΠΎΠΏΠ»Π΅Π½ΠΈΠ΅ΠΌ Π½Π° Π³ΡΠ°ΡΠΈΡΠΎΠ²ΠΎΠΌ ΡΠ»Π΅ΠΊΡΡΠΎΠ΄Π΅
ΠΠΎΠ±ΠΈΠ»ΡΠ½ΡΠΉ ΡΡΠ°Π½ΡΠΏΠΎΡΡΠ½ΡΠΉ ΠΊΠΎΠΌΠΏΠ»Π΅ΠΊΡ Π΄Π»Ρ Π°ΡΡ Π΅ΠΎΠ»ΠΎΠ³ΠΈΡΠ΅ΡΠΊΠΈΡ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΠΉ
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
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