2,473 research outputs found
Inter-meson Potentials in Dual Ginzburg-Landau Theory
We calculate inter-meson potentials numerically by solving classical
equations of motion derived from Dual Ginzburg-Landau (DGL) Theory. Inter-meson
potentials in DGL theory are shown to be similar to those of the string-flip
model and well reproduce behaviors of the short-range interaction at the
classical level. We also compare our results with those from lattice QCD Monte
carlo calculations.Comment: 18 pages, latex, 8 figure
Non-commutative hypergroup of order five
We prove that all hypergroups of order four are commutative and that there
exists a non-comutative hypergroup of order five. These facts imply that the
minimum order of non-commutative hypergroups is five even though the minimum
order of non-commutative groups is six
Non-commutative hypergroup of order five
We prove that all hypergroups of order four are commutative and that there exists a non-comutative hypergroup of order five. These facts imply that the minimum order of non-commutative hypergroups is five, even though the minimum order of non-commutative groups is six.ArticleJournal of Algebra and Its Applications.16(7):1750127(2016)journal articl
Consistent map building in petrochemical complexes for firefighter robots using SLAM based on GPS and LIDAR
The objective of this study was to achieve simultaneous localization and mapping (SLAM) of firefighter robots for petrochemical complexes. Consistency of the SLAM map is important because human operators compare the map with aerial images and identify target positions on the map. The global positioning system (GPS) enables increased consistency. Therefore, this paper describes two Rao-Blackwellized particle filters (RBPFs) based on GPS and light detection and ranging (LIDAR) as SLAM solutions. Fast-SLAM 1.0 and Fast-SLAM 2.0 were used in grid maps for RBPFs in this study. We herein propose the use of Fast-SLAM to combine GPS and LIDAR. The difference between the original Fast-SLAM and the proposed method is the use of the log-likelihood function of GPS; the proposed combination method is implemented using a probabilistic mathematics formulation. The proposed methods were evaluated using sensor data measured in a real petrochemical complex in Japan ranging in size from 550–380 m. RTK-GPS data was used for the GPS measurement and had an availability of 56%. Our results showed that Fast-SLAM 2.0 based on GPS and LIDAR in a dense grid map produced the best results. There was significant improvement in alignment to aerial data, and the mean square root error was 0.65 m. To evaluate the mapping consistency, accurate 3D point cloud data measured by Faro Focus 3D (± 3 mm) was used as the ground truth. Building sizes were compared; the minimum mean errors were 0.17 and 0.08 m for the oil refinery and management building area and the area of a sparse building layout with large oil tanks, respectively. Consequently, a consistent map, which was also consistent with an aerial map (from Google Maps), was built by Fast-SLAM 1.0 and 2.0 based on GPS and LIDAR. Our method reproduced map consistency results for ten runs with a variance of ± 0.3 m. Our method reproduced map consistency results with a global accuracy of 0.52 m in a low RTK-Fix-GPS environment, which was a factory with a building layout similar to petrochemical complexes with 20.9% of RTK-Fix-GPS data availability
Hydrogen patterning of Ga1-xMnxAs for planar spintronics
We demonstrate two patterning techniques based on hydrogen passivation of
Ga1-xMnxAs to produce isolated ferromagnetically active regions embedded
uniformly in a paramagnetic, insulating host. The first method consists of
selective hydrogenation of Ga1-xMnxAs by lithographic masking. Magnetotransport
measurements of Hall-bars made in this manner display the characteristic
properties of the hole-mediated ferromagnetic phase, which result from good
pattern isolation. Arrays of Ga1-xMnxAs dots as small as 250 nm across have
been realized by this process. The second process consists of blanket
hydrogenation of Ga1-xMnxAs followed by local reactivation using confined
low-power pulsed-laser annealing. Conductance imaging reveals local electrical
reactivation of micrometer-sized regions that accompanies the restoration of
ferromagnetism. The spatial resolution achievable with this method can
potentially reach <100 nm by employing near-field laser processing. The high
spatial resolution attainable by hydrogenation patterning enables the
development of systems with novel functionalities such as lateral
spin-injection as well as the exploration of magnetization dynamics in
individual and coupled structures made from this novel class of semiconductors.Comment: ICDS-24, July 2007. 8 pages with 4 figure
Spin Injection into a Graphene Thin Film at Room Temperature
We demonstrate spin injection into a graphene thin film with high reliability
by using non-local magnetoresistance (MR) measurements, in which the electric
current path is completely separated from the spin current path. Using these
non-local measurements, an obvious MR effect was observed at room temperature;
and the MR effect was ascribed to magnetization reversal of ferromagnetic
electrodes. This result is a direct demonstration of spin injection into a
graphene thin film. Furthermore, this is the first report of spin injection
into molecules at room temperature.Comment: 12 pages, 3 figure
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