441 research outputs found
A Metric for Linear Temporal Logic
We propose a measure and a metric on the sets of infinite traces generated by
a set of atomic propositions. To compute these quantities, we first map
properties to subsets of the real numbers and then take the Lebesgue measure of
the resulting sets. We analyze how this measure is computed for Linear Temporal
Logic (LTL) formulas. An implementation for computing the measure of bounded
LTL properties is provided and explained. This implementation leverages SAT
model counting and effects independence checks on subexpressions to compute the
measure and metric compositionally
TOFTOF: Cold neutron time-of-flight spectrometer
TOFTOF, operated by the Technische Universität München, is a direct geometry disc-chopper time-of-flight spectrometer located in the Neutron Guide Hall West. It offers an excellent signal-to-background ratio, high energy resolution and high neutron flux. Adaptable for a wide range of sample environments, TOFTOF is ideal for investigations of fundamental concepts and challenges in physics and materials science
Effect of dislocations on charge carrier mobility-lifetime product in synthetic single crystal diamond
The authors report correlations between variations in charge transport of electrons and holes in synthetic single crystal diamond and the presence of nitrogen impurities and dislocations. The spatial distribution of these defects was imaged using their characteristic luminescence emission and compared with maps of carrier drift length measured by ion beam induced charge imaging. The images indicate a reduction of electron and hole mobility-lifetime product due to nitrogen impurities and dislocations. Very good charge transport is achieved in selected regions where the dislocation density is minimal
Mg-Ni-H films as selective coatings: tunable reflectance by layered hydrogenation
Unlike other switchable mirrors, Mg2NiHx films show large changes in
reflection that yield very low reflectance (high absorptance) at different
hydrogen contents, far before reaching the semiconducting state. The resulting
reflectance patterns are of interference origin, due to a self-organized
layered hydrogenation mechanism that starts at the substrate interface, and can
therefore be tuned by varying the film thickness. This tunability, together
with the high absorptance contrast observed between the solar and the thermal
energies, strongly suggests the use of these films in smart coatings for solar
applications.Comment: Three two-column pages with 3 figures embedded; RevTE
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