6,714 research outputs found
Evaluation of bistable systems versus matched filters in detecting bipolar pulse signals
This paper presents a thorough evaluation of a bistable system versus a
matched filter in detecting bipolar pulse signals. The detectability of the
bistable system can be optimized by adding noise, i.e. the stochastic resonance
(SR) phenomenon. This SR effect is also demonstrated by approximate statistical
detection theory of the bistable system and corresponding numerical
simulations. Furthermore, the performance comparison results between the
bistable system and the matched filter show that (a) the bistable system is
more robust than the matched filter in detecting signals with disturbed pulse
rates, and (b) the bistable system approaches the performance of the matched
filter in detecting unknown arrival times of received signals, with an
especially better computational efficiency. These significant results verify
the potential applicability of the bistable system in signal detection field.Comment: 15 pages, 9 figures, MikTex v2.
Noise-Enhanced Information Systems
Noise, traditionally defined as an unwanted signal or disturbance, has been shown to play an important constructive role in many information processing systems and algorithms. This noise enhancement has been observed and employed in many physical, biological, and engineered systems. Indeed stochastic facilitation (SF) has been found critical for certain biological information functions such as detection of weak, subthreshold stimuli or suprathreshold signals through both experimental verification and analytical model simulations. In this paper, we present a systematic noise-enhanced information processing framework to analyze and optimize the performance of engineered systems. System performance is evaluated not only in terms of signal-to-noise ratio but also in terms of other more relevant metrics such as probability of error for signal detection or mean square error for parameter estimation. As an important new instance of SF, we also discuss the constructive effect of noise in associative memory recall. Potential enhancement of image processing systems via the addition of noise is discussed with important applications in biomedical image enhancement, image denoising, and classification
Survival of orbiting in Ne (7 - 10 MeV/nucleon) + C reactions
The inclusive energy distributions of fragments with Z 3 emitted from
the bombardment of C by Ne beams with incident energies between
145 and 200 MeV have been measured in the angular range
10 - 50. Damped fragment yields in all cases have been found to
be characteristic of emission from fully energy equilibrated composites; for B,
C fragments, average Q-values, , were independent of the centre of mass
emission angle (), and the angular distributions followed
1/sin like variation, signifying long life times of the
emitting di-nuclear systems. Total yields of these fragments have been found to
be much larger compared to the standard statistical model predictions of the
same. This may be indicative of the survival of orbiting like process in
C + Ne system at these energies.Comment: 7 pages, 5 figures, accepted for publication in Phys. Rev. C (Rapid
Communication
The stochastic dynamics of nanoscale mechanical oscillators immersed in a viscous fluid
The stochastic response of nanoscale oscillators of arbitrary geometry
immersed in a viscous fluid is studied. Using the fluctuation-dissipation
theorem it is shown that deterministic calculations of the governing fluid and
solid equations can be used in a straightforward manner to directly calculate
the stochastic response that would be measured in experiment. We use this
approach to investigate the fluid coupled motion of single and multiple
cantilevers with experimentally motivated geometries.Comment: 5 pages, 5 figure
Quark Matter and Nuclear Collisions: A Brief History of Strong Interaction Thermodynamics
The past fifty years have seen the emergence of a new field of research in
physics, the study of matter at extreme temperatures and densities. The theory
of strong interactions, quantum chromodynamics (QCD), predicts that in this
limit, matter will become a plasma of deconfined quarks and gluons -- the
medium which made up the early universe in the first 10 microseconds after the
big bang. High energy nuclear collisions are expected to produce short-lived
bubbles of such a medium in the laboratory. I survey the merger of statistical
QCD and nuclear collision studies for the analysis of strongly interacting
matter in theory and experiment.Comment: 24 pages, 14 figures Opening Talk at the 5th Berkeley School on
Collective Dynamics in High Energy Collisions, LBNL Berkeley/California, May
14 - 18, 201
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