428 research outputs found
SEGCloud: Semantic Segmentation of 3D Point Clouds
3D semantic scene labeling is fundamental to agents operating in the real
world. In particular, labeling raw 3D point sets from sensors provides
fine-grained semantics. Recent works leverage the capabilities of Neural
Networks (NNs), but are limited to coarse voxel predictions and do not
explicitly enforce global consistency. We present SEGCloud, an end-to-end
framework to obtain 3D point-level segmentation that combines the advantages of
NNs, trilinear interpolation(TI) and fully connected Conditional Random Fields
(FC-CRF). Coarse voxel predictions from a 3D Fully Convolutional NN are
transferred back to the raw 3D points via trilinear interpolation. Then the
FC-CRF enforces global consistency and provides fine-grained semantics on the
points. We implement the latter as a differentiable Recurrent NN to allow joint
optimization. We evaluate the framework on two indoor and two outdoor 3D
datasets (NYU V2, S3DIS, KITTI, Semantic3D.net), and show performance
comparable or superior to the state-of-the-art on all datasets.Comment: Accepted as a spotlight at the International Conference of 3D Vision
(3DV 2017
Evolution of electromagnetic and Dirac perturbations around a black hole in Horava gravity
The evolution of electromagnetic and Dirac perturbations in the spacetime
geometry of Kehagias-Sfetsos(KS) black hole in the deformed Horava-Lifshitz(HL)
gravity is investigated and the associated quasinormal modes are evaluated
using time domain integration and WKB methods. We find a considerable deviation
in the nature of field evolution in HL theory from that in the Schwarzschild
spacetime and QNMs region extends over a longer time in HL theory before the
power-law tail decay begins. The dependence of the field evolution on the HL
parameter are studied. In the time domain picture we find that the
length of QNM region increases with . But the late time decay of field
follows the same power-law tail behavior as in the case of Schwarzschild black
hole.Comment: The article was fully rewritten, references added, to appear in MPL
Particle Probe of Horava-Lifshitz Gravity
Kehagias-Sfetsos black hole in Ho\v{r}ava-Lifshitz gravity is probed through
particle geodesics. Gravitational force of KS black hole becomes weaker than
that of Schwarzschild around horizon and interior space. Particles can be
always scattered or trapped in new closed orbits, unlike those falling forever
in Schwarzschild black. The properties of null and timelike geodesics are
classified with values of coupling constants. The precession rates of the
orbits are evaluated. The time trajectories are also classified under different
values of coupling constants for both null and timelike geodesics. Physical
phenomena that may be observable are discussed.Comment: 10 pages, 8 figure
Production and optical properties of liquid scintillator for the JSNS experiment
The JSNS (J-PARC Sterile Neutrino Search at J-PARC Spallation Neutron
Source) experiment will search for neutrino oscillations over a 24 m short
baseline at J-PARC. The JSNS inner detector will be filled with 17 tons
of gadolinium-loaded liquid scintillator (LS) with an additional 31 tons of
unloaded LS in the intermediate -catcher and outer veto volumes.
JSNS has chosen Linear Alkyl Benzene (LAB) as an organic solvent because
of its chemical properties. The unloaded LS was produced at a refurbished
facility, originally used for scintillator production by the RENO experiment.
JSNS plans to use ISO tanks for the storage and transportation of the LS.
In this paper, we describe the LS production, and present measurements of its
optical properties and long term stability. Our measurements show that storing
the LS in ISO tanks does not result in degradation of its optical properties.Comment: 7 pages, 4 figures
Towards a Holographic Model of the QCD Phase Diagram
We describe the temperature-chemical potential phase diagrams of holographic
models of a range of strongly coupled gauge theories that display chiral
symmetry breaking/restoration transitions. The models are based on the
D3/probe-D7 system but with a phenomenologically chosen running
coupling/dilaton profile. We realize chiral phase transitions with either
temperature or density that are first or second order by changing the dilaton
profile. Although the models are only caricatures of QCD they show that
holographic models can capture many aspects of the QCD phase diagram and hint
at the dependence on the running coupling.Comment: 11 pages, 9 figures, v2: minor corrections, Invited contribution to
an AdS/CFT edition of Journal of Physics
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