383 research outputs found
Binary Classifier Calibration using an Ensemble of Near Isotonic Regression Models
Learning accurate probabilistic models from data is crucial in many practical
tasks in data mining. In this paper we present a new non-parametric calibration
method called \textit{ensemble of near isotonic regression} (ENIR). The method
can be considered as an extension of BBQ, a recently proposed calibration
method, as well as the commonly used calibration method based on isotonic
regression. ENIR is designed to address the key limitation of isotonic
regression which is the monotonicity assumption of the predictions. Similar to
BBQ, the method post-processes the output of a binary classifier to obtain
calibrated probabilities. Thus it can be combined with many existing
classification models. We demonstrate the performance of ENIR on synthetic and
real datasets for the commonly used binary classification models. Experimental
results show that the method outperforms several common binary classifier
calibration methods. In particular on the real data, ENIR commonly performs
statistically significantly better than the other methods, and never worse. It
is able to improve the calibration power of classifiers, while retaining their
discrimination power. The method is also computationally tractable for large
scale datasets, as it is time, where is the number of
samples
Optomechanical circuits for nanomechanical continuous variable quantum state processing
We propose and analyze a nanomechanical architecture where light is used to
perform linear quantum operations on a set of many vibrational modes. Suitable
amplitude modulation of a single laser beam is shown to generate squeezing,
entanglement, and state-transfer between modes that are selected according to
their mechanical oscillation frequency. Current optomechanical devices based on
photonic crystals may provide a platform for realizing this scheme.Comment: 11 pages, 5 figure
Continuous mode cooling and phonon routers for phononic quantum networks
We study the implementation of quantum state transfer protocols in phonon
networks, where in analogy to optical networks, quantum information is
transmitted through propagating phonons in extended mechanical resonator arrays
or phonon waveguides. We describe how the problem of a non-vanishing thermal
occupation of the phononic quantum channel can be overcome by implementing
optomechanical multi- and continuous mode cooling schemes to create a 'cold'
frequency window for transmitting quantum states. In addition, we discuss the
implementation of phonon circulators and switchable phonon routers, which rely
on strong coherent optomechanical interactions only, and do not require strong
magnetic fields or specific materials. Both techniques can be applied and
adapted to various physical implementations, where phonons coupled to spin or
charge based qubits are used for on-chip networking applications.Comment: 33 pages, 8 figures. Final version, a few minor changes and updated
reference
Therapeutic Effect of Sodium Selenite and Zinc Sulphate as Supplementary with Meglumine Antimoniate( Glucantime®) Against Cutaneous Leishmaniasis In BALB/C Mice
Background: Successful therapy of leishmaniasis depends on effective cellular immune response. We evaluated the effectiveness of sodium selenite and zinc sulphate as known immunomodulator materials, in combination with Glucantime® in treatment of cutaneous leishmaniasis lesions resulting from Leishmania major in susceptible animal model.Methods: Thirty three female mice weighing 18-20 g at the age of 7-8 week infected with L. major were randomly divided into 3 groups: group1: treated by sodium selenite (0.35 mg/kg for 30 days), group2: treated by zinc sulphate (2 mg/kg for 30 days) and group3: treated by distilled water (0.01 ml/gr body weight for 30 days) as control. All groups received Glucantime® as a standard anti- leishmanial agent (60 mg/kg, ip) for 14 days. To assess the results of treatment measurement of lesions size and parasitological tests were done weekly.Results: The lesion sizes increased continuously in sodium selenite group .Although, in zinc group did not increase compared to baseline But with considering the time- group interaction there was no significant difference between zinc and control group during this study. There was no difference between lesion sizes and Leishmanial loads in the interventional and control groups, respectively.Conclusion: Sodium selenite and zinc sulphate at mentioned doses and duration of treatment did not show any treatment effect on cutaneous leishmaniasis caused by L. major in BALB/c mice. Increasing the dose of supplements and considering the follow up period after treatment can help more certain conclusion
Coherent optical wavelength conversion via cavity-optomechanics
We theoretically propose and experimentally demonstrate coherent wavelength
conversion of optical photons using photon-phonon translation in a
cavity-optomechanical system. For an engineered silicon optomechanical crystal
nanocavity supporting a 4 GHz localized phonon mode, optical signals in a 1.5
MHz bandwidth are coherently converted over a 11.2 THz frequency span between
one cavity mode at wavelength 1460 nm and a second cavity mode at 1545 nm with
a 93% internal (2% external) peak efficiency. The thermal and quantum limiting
noise involved in the conversion process is also analyzed, and in terms of an
equivalent photon number signal level are found to correspond to an internal
noise level of only 6 and 4x10-3 quanta, respectively.Comment: 11 pages, 7 figures, appendi
Cavity optomechanics with Si3N4 membranes at cryogenic temperatures
We describe a cryogenic cavity-optomechanical system that combines Si3N4
membranes with a mechanically-rigid Fabry-Perot cavity. The extremely high
quality-factor frequency products of the membranes allow us to cool a MHz
mechanical mode to a phonon occupation of less than 10, starting at a bath
temperature of 5 kelvin. We show that even at cold temperatures
thermally-occupied mechanical modes of the cavity elements can be a limitation,
and we discuss methods to reduce these effects sufficiently to achieve ground
state cooling. This promising new platform should have versatile uses for
hybrid devices and searches for radiation pressure shot noise.Comment: 19 pages, 5 figures, submitted to New Journal of Physic
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