11,203 research outputs found
Direct control of the tunnel splitting in a one-electron double quantum dot
Quasi-static transport measurements are employed on a laterally defined
tunnel-coupled double quantum dot. A nearby quantum point contact allows us to
track the charge as added to the device. If charged with only up to one
electron, the low-energy spectrum of the double quantum dot is characterized by
its quantum mechanical interdot tunnel splitting. We directly measure its
magnitude by utilizing particular anticrossing features in the stability
diagram at finite source-drain bias. By modification of gate voltages defining
the confinement potential as well as by variation of a perpendicular magnetic
field we demonstrate the tunability of the coherent tunnel coupling.Comment: High resolution pdf file available at
http://www2.nano.physik.uni-muenchen.de/~huettel/research/anticrossing.pd
AIOps for a Cloud Object Storage Service
With the growing reliance on the ubiquitous availability of IT systems and
services, these systems become more global, scaled, and complex to operate. To
maintain business viability, IT service providers must put in place reliable
and cost efficient operations support. Artificial Intelligence for IT
Operations (AIOps) is a promising technology for alleviating operational
complexity of IT systems and services. AIOps platforms utilize big data,
machine learning and other advanced analytics technologies to enhance IT
operations with proactive actionable dynamic insight.
In this paper we share our experience applying the AIOps approach to a
production cloud object storage service to get actionable insights into
system's behavior and health. We describe a real-life production cloud scale
service and its operational data, present the AIOps platform we have created,
and show how it has helped us resolving operational pain points.Comment: 5 page
Rhythmic inhibition allows neural networks to search for maximally consistent states
Gamma-band rhythmic inhibition is a ubiquitous phenomenon in neural circuits
yet its computational role still remains elusive. We show that a model of
Gamma-band rhythmic inhibition allows networks of coupled cortical circuit
motifs to search for network configurations that best reconcile external inputs
with an internal consistency model encoded in the network connectivity. We show
that Hebbian plasticity allows the networks to learn the consistency model by
example. The search dynamics driven by rhythmic inhibition enable the described
networks to solve difficult constraint satisfaction problems without making
assumptions about the form of stochastic fluctuations in the network. We show
that the search dynamics are well approximated by a stochastic sampling
process. We use the described networks to reproduce perceptual multi-stability
phenomena with switching times that are a good match to experimental data and
show that they provide a general neural framework which can be used to model
other 'perceptual inference' phenomena
Entanglement verification for quantum key distribution systems with an underlying bipartite qubit-mode structure
We consider entanglement detection for quantum key distribution systems that
use two signal states and continuous variable measurements. This problem can be
formulated as a separability problem in a qubit-mode system. To verify
entanglement, we introduce an object that combines the covariance matrix of the
mode with the density matrix of the qubit. We derive necessary separability
criteria for this scenario. These criteria can be readily evaluated using
semidefinite programming and we apply them to the specific quantum key
distribution protocol.Comment: 6 pages, 2 figures, v2: final versio
Ricci Collineations of the Bianchi Type II, VIII, and IX Space-times
Ricci and contracted Ricci collineations of the Bianchi type II, VIII, and IX
space-times, associated with the vector fields of the form (i) one component of
is different from zero and (ii) two components of are
different from zero, for , are presented. In subcase (i.b), which
is , some known solutions are found, and in subcase
(i.d), which is , choosing ,
the Bianchi type II, VIII, and IX space-times is reduced to the
Robertson-Walker metric.Comment: 12 Pages, LaTeX, 1 Table, no figure
Sortenevaluierung in Deutschland zugelassener Wintergersten (Hordeum vulgare) hinsichtlich Flugbrand-Resistenz (Ustilago nuda) und Hartbrandresistenz (Ustilago hordei)
Dem Ökologischen Landbau stehen derzeit keine richtlinienkonformen Verfahren mit ausreichender Wirksamkeit und/oder arbeitstechnischer Effizienz zur Verfügung, um die gesetzlichen Auflagen in der Saatgut-Produktion einzuhalten. Schon mehr als drei bzw. fünf an Flug- und/oder Hartbrand erkrankte Ähren pro 150 qm in der Basis- bzw. Z-Saatguterzeugung führen zur Aberkennung der Vermehrungsbestände und somit zu beträchtlichen finanziellen Einbußen. Einen Ausweg böte der Anbau von resistenten Sorten. Hierzu wurden 2002-03 und 2004-05 die verfügbaren Handelssorten auf ihre Anfälligkeit gegenüber Hartbrand und seit 2000 insgesamt 274 Wintergerste-Genbankmuster bzw. Handelssorten gegenüber Gerstenflugbrand geprüft
Intensity interferometry of single x-ray pulses from a synchrotron storage ring
We report on measurements of second-order intensity correlations at the high
brilliance storage ring PETRA III using a prototype of the newly developed
Adaptive Gain Integrating Pixel Detector (AGIPD). The detector recorded
individual synchrotron radiation pulses with an x-ray photon energy of 14.4 keV
and repetition rate of about 5 MHz. The second-order intensity correlation
function was measured simultaneously at different spatial separations that
allowed to determine the transverse coherence length at these x-ray energies.
The measured values are in a good agreement with theoretical simulations based
on the Gaussian Schell-model.Comment: 16 pages, 6 figures, 42 reference
In Things We Trust? Towards trustability in the Internet of Things
This essay discusses the main privacy, security and trustability issues with
the Internet of Things
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