12,251 research outputs found
Real-time image streaming over a low-bandwidth wireless camera network
In this paper we describe the recent development of a low-bandwidth wireless camera sensor network. We propose a simple, yet effective, network architecture which allows multiple cameras to be connected to the network and synchronize their communication schedules. Image compression of greater than 90% is performed at each node running on a local DSP coprocessor, resulting in nodes using 1/8th the energy compared to streaming uncompressed images. We briefly introduce the Fleck wireless node and the DSP/camera sensor, and then outline the network architecture and compression algorithm. The system is able to stream color QVGA images over the network to a base station at up to 2 frames per second. Ă© 2007 IEEE
Mn induced modifications of Ga 3d photoemission from (Ga, Mn)As: evidence for long range effects
Using synchrotron based photoemission, we have investigated the Mn-induced
changes in Ga 3d core level spectra from as-grown . Although Mn is located in Ga substitutional sites, and does
therefore not have any Ga nearest neighbours, the impact of Mn on the Ga core
level spectra is pronounced even at Mn concentrations in the range of 0.5%. The
analysis shows that each Mn atom affects a volume corresponding to a sphere
with around 1.4 nm diameter.Comment: Submitted to Physical Review B, Brief Repor
Dynamical oscillations in nonlinear optical media
The spatial dynamics of pulses in Kerr media with parabolic index profile are
examined. It is found that when diffraction and graded-index have opposite
signs propagating pulses exhibit an oscillatory pattern, similar to a breathing
behavior. Furthermore, if the pulse and the index profile are not aligned the
pulse oscillates around the index origin with frequency that depends on the
values of the diffraction and index of refraction. These oscillations are not
observed when diffraction and graded-index share the same sign
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