6,974 research outputs found
A dynamic model for real-time tracking of hands in bimanual movements
The problem of hand tracking in the presence of occlusion is addressed. In bimanual movements the hands tend to be synchronised effortlessly. Different aspects of this synchronisation are the basis of our research to track the hands. The spatial synchronisation in bimanual movements is modelled by the position and the temporal synchronisation by the velocity and acceleration of each hand. Based on a dynamic model, we introduce algorithms for occlusion detection and hand tracking
Numerical modelling of heat transfer and experimental validation in Powder-Bed Fusion with the Virtual Domain Approximation
Among metal additive manufacturing technologies, powder-bed fusion features
very thin layers and rapid solidification rates, leading to long build jobs and
a highly localized process. Many efforts are being devoted to accelerate
simulation times for practical industrial applications. The new approach
suggested here, the virtual domain approximation, is a physics-based rationale
for spatial reduction of the domain in the thermal finite-element analysis at
the part scale. Computational experiments address, among others, validation
against a large physical experiment of 17.5 of deposited
volume in 647 layers. For fast and automatic parameter estimation at such level
of complexity, a high-performance computing framework is employed. It couples
FEMPAR-AM, a specialized parallel finite-element software, with Dakota, for the
parametric exploration. Compared to previous state-of-the-art, this formulation
provides higher accuracy at the same computational cost. This sets the path to
a fully virtualized model, considering an upwards-moving domain covering the
last printed layers
On the two-dimensional rotational body of maximal Newtonian resistance
We investigate, by means of computer simulations, shapes of nonconvex bodies
that maximize resistance to their motion through a rarefied medium, considering
that bodies are moving forward and at the same time slowly rotating. A
two-dimensional geometric shape that confers to the body a resistance very
close to the theoretical supremum value is obtained, improving previous
results.Comment: This is a preprint version of the paper published in J. Math. Sci.
(N. Y.), Vol. 161, no. 6, 2009, 811--819. DOI:10.1007/s10958-009-9602-
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