1,172 research outputs found
Online change detection for energy-efficient mobilec crowdsensing
Mobile crowdsensing is power hungry since it requires continuously and simultaneously sensing, processing and uploading fused data from various sensor types including motion sensors and environment sensors. Realizing that being able to pinpoint change points of contexts enables energy-efficient mobile crowdsensing, we modify histogram-based techniques to efficiently detect changes, which has less computational complexity and performs better than the conventional techniques. To evaluate our proposed technique, we conducted experiments on real audio databases comprising 200 sound tracks. We also compare our change detection with multivariate normal distribution and one-class support vector machine. The results show that our proposed technique is more practical for mobile crowdsensing. For example, we show that it is possible to save 80% resource compared to standard continuous sensing while remaining detection sensitivity above 95%. This work enables energy-efficient mobile crowdsensing applications by adapting to contexts
Defect and anisotropic gap induced quasi-one-dimensional modulation of local density of states in YBaCuO
Motivated by recent angle-resolved photoemission spectroscopy (ARPES)
measurement that superconducting YBaCuO (YBCO) exhibits a
-symmetry gap, we show possible quasi-one-dimensional
modulations of local density of states in YBCO. These aniostropic gap and
defect induced stripe structures are most conspicuous at higher biases and
arise due to the nesting effect associated with a Fermi liquid. Observation of
these spectra by scanning tunneling microscopy (STM) would unify the picture
among STM, ARPES, and inelastic neutron scattering for YBCO.Comment: 4 pages, 4 figure
Detecting Current Noise with a Josephson Junction in the Macroscopic Quantum Tunneling Regime
We discuss the use of a hysteretic Josephson junction to detect current
fluctuations with frequencies below the plasma frequency of the junction. These
adiabatic fluctuations are probed by switching measurements observing the
noise-affected average rate of macroscopic quantum tunneling of the detector
junction out of its zero-voltage state. In a proposed experimental scheme,
frequencies of the noise are limited by an on-chip filtering circuit. The third
cumulant of current fluctuations at the detector is related to an asymmetry of
the switching rates.Comment: 26 pages, 10 figures. To appear in Journal of Low Temperature Physics
in the proceedings of the ULTI conference organized in Lammi, Finland (2006
Doping dependence of the resonance peak and incommensuration in high- superconductors
The doping and frequency evolutions of the incommensurate spin response and
the resonance mode are studied based on the scenario of the Fermi surface
topology. We use the slave-boson mean-field approach to the
model and including the antiferromagnetic fluctuation correction in the
random-phase approximation. We find that the equality between the
incommensurability and the hole concentration is reproduced at low frequencies
in the underdoped regime. This equality observed in experiments was explained
{\it only} based on the stripe model before. We also obtain the downward
dispersion for the spin response and predict its doping dependence for further
experimental testing, as well as a proportionality between the low-energy
incommensurability and the resonance energy. Our results suggest a common
origin for the incommensuration and the resonance peak based on the Fermi
surface topology and the d-wave symmetry.Comment: 5 pages, 4 PS figure
Nanofabrication by magnetic focusing of supersonic beams
We present a new method for nanoscale atom lithography. We propose the use of
a supersonic atomic beam, which provides an extremely high-brightness and cold
source of fast atoms. The atoms are to be focused onto a substrate using a thin
magnetic film, into which apertures with widths on the order of 100 nm have
been etched. Focused spot sizes near or below 10 nm, with focal lengths on the
order of 10 microns, are predicted. This scheme is applicable both to precision
patterning of surfaces with metastable atomic beams and to direct deposition of
material.Comment: 4 pages, 3 figure
Numerical analysis of the radio-frequency single-electron transistor operation
We have analyzed numerically the response and noise-limited charge
sensitivity of a radio-frequency single-electron transistor (RF-SET) in a
non-superconducting state using the orthodox theory. In particular, we have
studied the performance dependence on the quality factor Q of the tank circuit
for Q both below and above the value corresponding to the impedance matching
between the coaxial cable and SET.Comment: 14 page
Confirmation of a pi_1^0 Exotic Meson in the \eta \pi^0 System
The exclusive reaction , at 18 GeV has been studied with a partial wave analysis on a sample
of 23~492 events from BNL experiment E852. A mass-dependent fit
is consistent with a resonant hypothesis for the wave, thus providing
evidence for a neutral exotic meson with , a mass of MeV, and a width of MeV. New
interpretations of the meson exotics in neutral system observed in
E852 and Crystal Barrel experiments are discussed.Comment: p3, rewording the paragraph (at the bottom) about the phase
variations. p4, rewording paragrath "The second method ..." . p4, at the
bottom of paragrath "The third method ..." added consistent with the results
of methods 1 and 2
Exotic Meson Production in the System observed in the Reaction at 18 GeV/c
This letter reports results from the partial wave analysis of the
final state in collisions at 18GeV/c.
Strong evidence is observed for production of two mesons with exotic quantum
numbers of spin, parity and charge conjugation, in the decay
channel . The mass MeV/c^2 and
width MeV/c^2 of the first state are consistent
with the parameters of the previously observed . The second
resonance with mass MeV/c^2 and width MeV/c^2 agrees very well with predictions from theoretical
models. In addition, the presence of is confirmed with mass MeV/c^2 and width MeV/c^2
and a new state, , is observed with mass
MeV/c^2 and width MeV/c^2. The decay properties of
these last two states are consistent with flux tube model predictions for
hybrid mesons with non-exotic quantum numbers
Knowledge-based energy functions for computational studies of proteins
This chapter discusses theoretical framework and methods for developing
knowledge-based potential functions essential for protein structure prediction,
protein-protein interaction, and protein sequence design. We discuss in some
details about the Miyazawa-Jernigan contact statistical potential,
distance-dependent statistical potentials, as well as geometric statistical
potentials. We also describe a geometric model for developing both linear and
non-linear potential functions by optimization. Applications of knowledge-based
potential functions in protein-decoy discrimination, in protein-protein
interactions, and in protein design are then described. Several issues of
knowledge-based potential functions are finally discussed.Comment: 57 pages, 6 figures. To be published in a book by Springe
Observation of Pseudoscalar and Axial Vector Resonances in pi- p -> K+ K- pi0 n at 18 GeV
A new measurement of the reaction pi- p -> K+ K- pi0 n has been made at a
beam energy of 18 GeV. A partial wave analysis of the K+ K- pi0 system shows
evidence for three pseudoscalar resonances, eta(1295), eta(1416), and
eta(1485), as well as two axial vectors, f1(1285), and f1(1420). Their observed
masses, widths and decay properties are reported. No signal was observed for
C(1480), an IG J{PC} = 1+ 1{--} state previously reported in phi pi0 decay.Comment: 7 pages, 6 figs, to be submitted to Phys. Let
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