10,544 research outputs found
A Method to Separate Stochastic and Deterministic Information from Electrocardiograms
In this work we present a new idea to develop a method to separate stochastic
and deterministic information contained in an electrocardiogram, ECG, which may
provide new sources of information with diagnostic purposes. We assume that the
ECG has information corresponding to many different processes related with the
cardiac activity as well as contamination from different sources related with
the measurement procedure and the nature of the observed system itself. The
method starts with the application of an improuved archetypal analysis to
separate the mentioned stochastic and deterministic information. From the
stochastic point of view we analyze Renyi entropies, and with respect to the
deterministic perspective we calculate the autocorrelation function and the
corresponding correlation time. We show that healthy and pathologic information
may be stochastic and/or deterministic, can be identified by different measures
and located in different parts of the ECG.Comment: 4 pages, 6 figure
Synchronization of interconnected networks: the role of connector nodes
In this Letter we identify the general rules that determine the
synchronization properties of interconnected networks. We study analytically,
numerically and experimentally how the degree of the nodes through which two
networks are connected influences the ability of the whole system to
synchronize. We show that connecting the high-degree (low-degree) nodes of each
network turns out to be the most (least) effective strategy to achieve
synchronization. We find the functional relation between synchronizability and
size for a given network-of-networks, and report the existence of the optimal
connector link weights for the different interconnection strategies. Finally,
we perform an electronic experiment with two coupled star networks and conclude
that the analytical results are indeed valid in the presence of noise and
parameter mismatches.Comment: Accepted for publication in Physical Review Letters. Main text: 5
pages, 4 figures. Supplemental material: 8 pages, 3 figure
Observation of a parity oscillation in the conductance of atomic wires
Using a scanning tunnel microscope or mechanically controlled break
junctions, atomic contacts of Au, Pt and Ir are pulled to form chains of atoms.
We have recorded traces of conductance during the pulling process and averaged
these for a large amount of contacts. An oscillatory evolution of conductance
is observed during the formation of the monoatomic chain suggesting a
dependence on even or odd numbers of atoms forming the chain. This behaviour is
not only present in the monovalent metal Au, as it has been previously
predicted, but is also found in the other metals which form chains suggesting
it to be a universal feature of atomic wires
D-LITE: Database of Light-Interacting Technologies for Architectural Envelopes
On-line catalogue on light-control technologies and their architectural implementation (cases studies + construction details + model
COSMOSOMAS Observations of the CMB and Galactic Foregrounds at 11 GHz: Evidence for anomalous microwave emission at high Galactic Latitude
We present observations with the new 11 GHz radiometer of the COSMOSOMAS
experiment at the Teide Observatory (Tenerife). The sky region between 0 deg <=
RA <= 360 deg and 26 deg <= DEC 49 deg (ca. 6500 square degrees) was observed
with an angular resolution of 0.9 deg. Two orthogonal independent channels in
the receiving system measured total power signals from linear polarizations
with a 2 GHz bandwidth. Maps with an average sensitivity of 50 microK per beam
have been obtained for each channel. At high Galactic latitude (|b|>30deg) the
11 GHz data are found to contain the expected cosmic microwave background as
well as extragalactic radiosources, galactic synchrotron and free-free
emission, and a dust-correlated component which is very likely of galactic
origin. At the angular scales allowed by the window function of the experiment,
the dust-correlated component presents an amplitude \Delta T aprox. 9-13 microK
while the CMB signal is of order 27 microK. The spectral behaviour of the
dust-correlated signal is examined in the light of previous COSMOSOMAS data at
13-17 GHz and WMAP data at 22-94 GHz in the same sky region. We detect a
flattening in the spectral index of this signal below 20 GHz which rules out
synchrotron radiation as being responsible for the emission. This anomalous
dust emission can be described by a combination of free-free emission and
spinning dust models with a flux density peaking around 20 GHz.Comment: 17 pages, 10 tables, 20 figures. Details on the COSMOSOMAS experiment
can be found at http://www.iac.es/project/cmb/cosmosomas
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