1,283 research outputs found
CHEMISTRY OF VIRAL INFECTED CELLS *
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73699/1/j.1749-6632.1960.tb20121.x.pd
Critical Fidelity
Using a Wigner Lorentzian Random Matrix ensemble, we study the fidelity,
, of systems at the Anderson metal-insulator transition, subject to small
perturbations that preserve the criticality. We find that there are three decay
regimes as perturbation strength increases: the first two are associated with a
gaussian and an exponential decay respectively and can be described using
Linear Response Theory. For stronger perturbations decays algebraically
as , where is the correlation dimension of the
critical eigenstates.Comment: 4 pages, 3 figures. Revised and published in Phys. Rev. Let
Sensor-based activity recognition with dynamically added context
An activity recognition system essentially processes raw sensor data and maps them into latent activity classes. Most of the previous systems are built with supervised learning techniques and pre-defined data sources, and result in static models. However, in realistic and dynamic environments, original data sources may fail and new data sources become available, a robust activity recognition system should be able to perform evolution automatically with dynamic sensor availability in dynamic environments. In this paper, we propose methods that automatically incorporate dynamically available data sources to adapt and refine the recognition system at run-time. The system is built upon ensemble classifiers which can automatically choose the features with the most discriminative power. Extensive experimental results with publicly available datasets demonstrate the effectiveness of our methods
Electrically pumped semiconductor laser with low spatial coherence and directional emission
We design and fabricate an on-chip laser source that produces a directional
beam with low spatial coherence. The lasing modes are based on the axial orbit
in a stable cavity and have good directionality. To reduce the spatial
coherence of emission, the number of transverse lasing modes is maximized by
fine-tuning the cavity geometry. Decoherence is reached in a few nanoseconds.
Such rapid decoherence will facilitate applications in ultrafast speckle-free
full-field imaging
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