227 research outputs found
Resolution-enhanced Mapping Spectrometer
A familiar mapping spectrometer implementation utilizes two dimensional detector arrays with spectral dispersion along one direction and spatial along the other. Spectral images are formed by spatially scanning across the scene (i.e., push-broom scanning). For imaging grating and prism spectrometers, the slit is perpendicular to the spatial scan direction. For spectrometers utilizing linearly variable focal-plane-mounted filters the spatial scan direction is perpendicular to the direction of spectral variation. These spectrometers share the common limitation that the number of spectral resolution elements is given by the number of pixels along the spectral (or dispersive) direction. Resolution enhancement by first passing the light input to the spectrometer through a scanned etalon or Michelson is discussed. Thus, while a detector element is scanned through a spatial resolution element of the scene, it is also temporally sampled. The analysis for all the pixels in the dispersive direction is addressed. Several specific examples are discussed. The alternate use of a Michelson for the same enhancement purpose is also discussed. Suitable for weight constrained deep space missions, hardware systems were developed including actuators, sensor, and electronics such that low-resolution etalons with performance required for implementation would weigh less than one pound
Non-additivity of Renyi entropy and Dvoretzky's Theorem
The goal of this note is to show that the analysis of the minimum output
p-Renyi entropy of a typical quantum channel essentially amounts to applying
Milman's version of Dvoretzky's Theorem about almost Euclidean sections of
high-dimensional convex bodies. This conceptually simplifies the
(nonconstructive) argument by Hayden-Winter disproving the additivity
conjecture for the minimal output p-Renyi entropy (for p>1).Comment: 8 pages, LaTeX; v2: added and updated references, minor editorial
changes, no content change
Decision with Bayesian network in the concurrent faults event
The purpose of this article is to present a new method for process diagnosis with Bayesian network. The interest of this method is to propose a new structure of Bayesian network allowing to diagnose a system with the model-based framework or with the data-driven framework. A particular interest of the proposed approach is the use of continuous nodes in the network in order to evaluate the status of the process. The effectiveness and performances of the method are illustrated on a heating water process corrupted by various faults
Using Bayesian networks for decision in the simultaneous faults case
The purpose of this article is to present a new method for process diagnosis with Bayesian network. The interest of this method is to propose a new structure of Bayesian network allowing to diagnose a system with the model-based framework or with the data-driven framework. A particular interest of the proposed approach is the use of continuous nodes in the network in order to evaluate the status of the process. The effectiveness and performances of the method are illustrated on a heating water process corrupted by various faults
How often is a random quantum state k-entangled?
The set of trace preserving, positive maps acting on density matrices of size
d forms a convex body. We investigate its nested subsets consisting of
k-positive maps, where k=2,...,d. Working with the measure induced by the
Hilbert-Schmidt distance we derive asymptotically tight bounds for the volumes
of these sets. Our results strongly suggest that the inner set of
(k+1)-positive maps forms a small fraction of the outer set of k-positive maps.
These results are related to analogous bounds for the relative volume of the
sets of k-entangled states describing a bipartite d X d system.Comment: 19 pages in latex, 1 figure include
Weak multiplicativity for random quantum channels
It is known that random quantum channels exhibit significant violations of
multiplicativity of maximum output p-norms for any p>1. In this work, we show
that a weaker variant of multiplicativity nevertheless holds for these
channels. For any constant p>1, given a random quantum channel N (i.e. a
channel whose Stinespring representation corresponds to a random subspace S),
we show that with high probability the maximum output p-norm of n copies of N
decays exponentially with n. The proof is based on relaxing the maximum output
infinity-norm of N to the operator norm of the partial transpose of the
projector onto S, then calculating upper bounds on this quantity using ideas
from random matrix theory.Comment: 21 pages; v2: corrections and additional remark
Multicentre, prospective, double-blind, randomised controlled clinical trial comparing different non-opioid analgesic combinations with morphine for postoperative analgesia: the OCTOPUS study
BACKGROUND: Head-to-head comparisons of combinations of more than one non-opioid analgesic (NOA) with morphine alone, for postoperative analgesia, are lacking. The objective of this multicentre, randomised, double-blind controlled trial was to compare the morphine-sparing effects of different combinations of three NOAs-paracetamol (P), nefopam (N), and ketoprofen (K)-for postoperative analgesia.
METHODS: Patients from 10 hospitals were randomised to one of eight groups: control (C) received saline as placebo, P, N, K, PN, PK, NK, and PNK. Treatments were given intravenously four times a day during the first 48 h after surgery, and morphine patient-controlled analgesia was used as rescue analgesia. The outcome measures were morphine consumption, pain scores, and morphine-related side-effects evaluated 24 and 48 h after surgery.
RESULTS: Two hundred and thirty-seven patients undergoing a major surgical procedure were included between July 2013 and November 2016. Despite a failure to reach a calculated sample size, 24 h morphine consumption [median (inter-quartile range)] was significantly reduced in the PNK group [5 (1-11) mg] compared with either the C group [27 (11-42) mg; P<0.05] or the N group [21 (12-29) mg; P<0.05]. Results were similar 48 h after surgery. Patients experienced less pain in the PNK group compared with the C, N, and P groups. No difference was observed in the incidence of morphine-related side-effects.
CONCLUSIONS: Combining three NOAs with morphine allows a significant morphine sparing for 48 h after surgery associated with superior analgesia the first 24 h when compared with morphine alone.
CLINICAL TRIAL REGISTRATION: EudraCT: 2012-004219-30; NCT01882530
Improved Unsteady RANS Models Applied to Jet Transverse to a Pipe Flow
An unsteady RANS model is developed in order to simulate the complex situations involving both free and bounded flows. This model tuned to catch coherent flow structures is developed both in the k-ε and k-l approaches. The full 3D geometry of a round jet exiting from a reservoir into a pipe has been computed. Periodic conditions are applied in order to compare with an experiments consisting of eight jets exiting in a cross pipe flow. Improvement has been obtained with this URANS turbulence model compared to RANS and good agreement compared with experiments has been obtained. Unsteady phenomena are reproduced by the model and provide more insight into the physical properties of the flow and of the transport of a passive scalar
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