9,365 research outputs found
Fast Monte-Carlo Localization on Aerial Vehicles using Approximate Continuous Belief Representations
Size, weight, and power constrained platforms impose constraints on
computational resources that introduce unique challenges in implementing
localization algorithms. We present a framework to perform fast localization on
such platforms enabled by the compressive capabilities of Gaussian Mixture
Model representations of point cloud data. Given raw structural data from a
depth sensor and pitch and roll estimates from an on-board attitude reference
system, a multi-hypothesis particle filter localizes the vehicle by exploiting
the likelihood of the data originating from the mixture model. We demonstrate
analysis of this likelihood in the vicinity of the ground truth pose and detail
its utilization in a particle filter-based vehicle localization strategy, and
later present results of real-time implementations on a desktop system and an
off-the-shelf embedded platform that outperform localization results from
running a state-of-the-art algorithm on the same environment
High-efficiency broad-bandwidth sub-wavelength grating based fibre-chip coupler in SOI
We report a comprehensive study on the performance of uniform and non-uniform
based subwavelength grating couplers in Silicon-on-Insulator. The two
performance metrics, coupling efficiency and bandwidth enhancement and
trade-offs is presented. We also present, design parameters to achieve
high-efficiency and broadband operation based on the detailed study of various
loss mechanisms in the grating. Based on the detailed analysis subwavelength
grating coupler designs with efficiency as high as 84 % with a 1 dB bandwidth
of 50 nm and 98 % with a 44 nm 1 dB bandwidth is presented
Noise-induced quantum transport
We analyze the problem of directed quantum transport induced by external
exponentially correlated telegraphic noise. In addition to quantum nature of
the heat bath, nonlinearity of the periodic system potential brings in quantum
contribution. We observe that quantization, in general, enhances classical
current at low temperature, while the differences become insignificant at
higher temperature. Interplay of quantum diffusion and quantum correction to
system potential is analyzed for various ranges of temperature, correlation
time and strength of external noise and asymmetry parameters. A possible
experimental realization of the observed quantum effects in a superionic
conductor placed in a random asymmetric dichotomous electric field has been
suggested.Comment: 23 pages and 5 figures. To be published in Physical Review
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