2,543 research outputs found
Plan-view Trajectory Estimation with Dense Stereo Background Models
In a known environment, objects may be tracked in multiple views using a set of back-ground models. Stereo-based models can be illumination-invariant, but often have undefined values which inevitably lead to foreground classification errors. We derive dense stereo models for object tracking using long-term, extended dynamic-range imagery, and by detecting and interpolating uniform but unoccluded planar regions. Foreground points are detected quickly in new images using pruned disparity search. We adopt a 'late-segmentation' strategy, using an integrated plan-view density representation. Foreground points are segmented into object regions only when a trajectory is finally estimated, using a dynamic programming-based method. Object entry and exit are optimally determined and are not restricted to special spatial zones
High Energy Physics from High Performance Computing
We discuss Quantum Chromodynamics calculations using the lattice regulator.
The theory of the strong force is a cornerstone of the Standard Model of
particle physics. We present USQCD collaboration results obtained on Argonne
National Lab's Intrepid supercomputer that deepen our understanding of these
fundamental theories of Nature and provide critical support to frontier
particle physics experiments and phenomenology.Comment: Proceedings of invited plenary talk given at SciDAC 2009, San Diego,
June 14-18, 2009, on behalf of the USQCD collaboratio
Does the Cambridge Automated Neuropsychological Test Battery (CANTAB) Distinguish Between Cognitive Domains in Healthy Older Adults?
The Cambridge Neuropsychological Test Automated Battery (CANTAB) is a semiautomated computer interface for assessing cognitive function. We examined whether CANTAB tests measured specific cognitive functions, using established neuropsychological tests as a reference point. A sample of 500 healthy older (M = 60.28 years, SD = 6.75) participants in the Tasmanian Healthy Brain Project completed battery of CANTAB subtests and standard paper-based neuropsychological tests. Confirmatory factor analysis identified four factors: processing speed, verbal ability, episodic memory, and working memory. However, CANTAB tests did not consistently load onto the cognitive domain factors derived from traditional measures of the same function. These results indicate that five of the six CANTAB subtests examined did not load onto single cognitive functions. These CANTAB tests may lack the sensitivity to measure discrete cognitive functions in healthy populations or may measure other cognitive domains not included in the traditional neuropsychological battery
Further education improves cognitive reserve and triggers improvement in selective cognitive functions in older adults: The Tasmanian Healthy Brain Project
Introduction The strong link between early-life education and subsequent reduced risk of dementia suggests that education in later life could enhance cognitive function and may reduce age-related cognitive decline and protect against dementia. Methods Episodic memory, working memory, executive function, and language processing performances were assessed annually over 4 years in 359 healthy older adults who attended university for a minimum of 12 months (intervention) and were compared against 100 healthy adult controls. Results Multiple group latent growth curve modeling revealed a significant improvement in language processing capacity over time in the intervention group. No changes were detected for episodic memory, working memory, or executive function. Discussion These results suggest that complex mental stimulation resulting from late-life further education results in improved crystallized knowledge but no changes to fluid cognitive functions. © 2017 The Author
Photo- and Electron-Production of Mesons on Nucleons and Nuclei
In these lectures I will show some results obtained with the chiral unitary
approach applied to the photo and electroproduction of mesons. The results for
photoproduction of and , together with
related reactions will be shown, having with common denominator the excitation
of the resonance which is one of those dynamically generated in
the chiral unitary approach. Then I will show results obtained for the reaction which reproduce the bulk of the data except for a
pronounced peak, giving support to a new mesonic resonance, X(2175). Results
will also be shown for the electromagnetic form factors of the
resonance, also dynamically generated in this approach. Finally, I will show
some results on the photoproduction of the in nuclei, showing that
present experimental results claiming a shift of the mass in the
medium are tied to a particular choice of background and are not conclusive.
One the other hand, the same experimental results show unambiguously a huge
increase of the width in the nuclear medium.Comment: Lecture at the "International School of Nuclear Physics", 29th Course
Quarks in Hadrons and Nuclei, Erice, Italy, September 2007. Note added in
Proofs concerning the mixed events technique and other comments on omega
productio
D-Brane Chemistry
We study several different kinds of bound states built from D-branes and
orientifolds. These states are to atoms what branonium - the bound state of a
brane and its anti-brane - is to positronium, inasmuch as they typically
involve a light brane bound to a much heavier object with conserved charges
which forbid the system's decay. We find the fully relativistic motion of a
probe Dp'-brane in the presence of source Dp-branes is integrable by
quadratures. Keplerian conic sections are obtained for special choices for p
and p' and the systems are shown to be equivalent to nonrelativistic systems.
Their quantum behaviour is also equivalent to the corresponding
non-relativistic limit. In particular the p=6, p'=0 case is equivalent to a
non-relativistic dyon in a magnetic monopole background, with the trajectories
in the surface of a cone. We also show that the motion of the probe branes
about D6-branes in IIA theory is equivalent to the motion of the corresponding
probes in the uplift to M-theory in 11 dimensions, for which there are no
D6-branes but their fields are replaced by a particular Taub-NUT geometry. We
further discuss the interactions of D-branes and orientifold planes having the
same dimension. this system behaves at large distances as a brane-brane system
but at shorter distances it does not have the tachyon instability.Comment: ref. added and typos correcte
Hawking radiation and thermodynamics of dynamical black holes in phantom dominated universe
The thermodynamic properties of dark energy-dominated universe in the
presence of a black hole are investigated in the general case of a varying
equation-of-state-parameter . We show that all the thermodynamics
quantities are regular at the phantom divide crossing, and particularly the
temperature and the entropy of the dark fluid are always positive definite. We
also study the accretion process of a phantom fluid by black holes and the
conditions required for the validity of the generalized second law of
thermodynamics. As a results we obtain a strictly negative chemical potential
and an equation-of-state parameter Comment: 22 pages,3 figure
Recommended from our members
Executive functioning, motor difficulties and developmental coordination disorder
The current study assessed a comprehensive range of executive functions (EFs) in children with poor motor skills, comparing profiles of children with a diagnosis of developmental coordination disorder (DCD) and those identified with motor difficulties (MD). Children in both groups performed more poorly than typically-developing controls on nonverbal measures of working memory, inhibition, planning and fluency, but not on tests of switching. The similar patterns of strengths and weaknesses in children with MD and DCD have important implications for parents, teachers and clinicians, as children with MD may struggle with EF tasks even though their motor difficulties are not identified
- …
