32,109 research outputs found
Humanoid Motion Description Language
In this paper we propose a description language for specifying motions for humanoid robots and for allowing humanoid robots to acquire motor skills. Locomotion greatly increases our ability to interact with our environments, which in turn increases our mental abilities. This principle also applies to humanoid robots. However, there are great difficulties to specify humanoid motions and to represent motor skills, which in most cases require four-dimensional space representations. We propose a representation framework that includes the following attributes: motion description layers, egocentric reference system, progressive quantized refinement, and automatic constraint satisfaction. We also outline strategies for acquiring new motor skills by learning from trial and error, macro approach, and programming. Then, we outline the development of a new humanoid motion description language called Cybele
Parametric high resolution techniques for radio astronomical imaging
The increased sensitivity of future radio telescopes will result in
requirements for higher dynamic range within the image as well as better
resolution and immunity to interference. In this paper we propose a new matrix
formulation of the imaging equation in the cases of non co-planar arrays and
polarimetric measurements. Then we improve our parametric imaging techniques in
terms of resolution and estimation accuracy. This is done by enhancing both the
MVDR parametric imaging, introducing alternative dirty images and by
introducing better power estimates based on least squares, with positive
semi-definite constraints. We also discuss the use of robust Capon beamforming
and semi-definite programming for solving the self-calibration problem.
Additionally we provide statistical analysis of the bias of the MVDR beamformer
for the case of moving array, which serves as a first step in analyzing
iterative approaches such as CLEAN and the techniques proposed in this paper.
Finally we demonstrate a full deconvolution process based on the parametric
imaging techniques and show its improved resolution and sensitivity compared to
the CLEAN method.Comment: To appear in IEEE Journal of Selected Topics in Signal Processing,
Special issue on Signal Processing for Astronomy and space research. 30 page
Sparsity and Parallel Acquisition: Optimal Uniform and Nonuniform Recovery Guarantees
The problem of multiple sensors simultaneously acquiring measurements of a
single object can be found in many applications. In this paper, we present the
optimal recovery guarantees for the recovery of compressible signals from
multi-sensor measurements using compressed sensing. In the first half of the
paper, we present both uniform and nonuniform recovery guarantees for the
conventional sparse signal model in a so-called distinct sensing scenario. In
the second half, using the so-called sparse and distributed signal model, we
present nonuniform recovery guarantees which effectively broaden the class of
sensing scenarios for which optimal recovery is possible, including to the
so-called identical sampling scenario. To verify our recovery guarantees we
provide several numerical results including phase transition curves and
numerically-computed bounds.Comment: 13 pages and 3 figure
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