1,183 research outputs found
A Continuous Electrophoretic Separation of the Radioactive Mixture 115 Cd- 114ln
A continuous electrophoretic separation of the mixture med
-:114In in a 0.1 N solutim;i. of KI in 0.01 N HBr, at a rate of 108 mg.
of Cd -172 mg. of In, and 4000 mg. of Cd - 396 mg. of In in 24 h.
is described
The gauging of two-dimensional bosonic sigma models on world-sheets with defects
We extend our analysis of the gauging of rigid symmetries in bosonic
two-dimensional sigma models with Wess-Zumino terms in the action to the case
of world-sheets with defects. A structure that permits a non-anomalous coupling
of such sigma models to world-sheet gauge fields of arbitrary topology is
analysed, together with obstructions to its existence, and the classification
of its inequivalent choices.Comment: 94 pages, 1 figur
Analog Property Checkers: A Ddr2 Case Study
The formal specification component of verification can be exported to simulation through the idea of property checkers. The essence of this approach is the automatic construction of an observer from the specification in the form of a program that can be interfaced with a simulator and alert the user if the property is violated by a simulation trace. Although not complete, this lighter approach to formal verification has been effectively used in software and digital hardware to detect errors. Recently, the idea of property checkers has been extended to analog and mixed-signal systems.
In this paper, we apply the property-based checking methodology to an industrial and realistic example of a DDR2 memory interface. The properties describing the DDR2 analog behavior are expressed in the formal specification language stl/psl in form of assertions. The simulation traces generated from an actual DDR2 interface design are checked with respect to the stl/psl assertions using the amt tool. The focus of this paper is on the translation of the official (informal and descriptive) specification of two non-trivial DDR2 properties into stl/psl assertions. We study both the benefits and the current limits of such approach
Sublinear Estimation of Weighted Matchings in Dynamic Data Streams
This paper presents an algorithm for estimating the weight of a maximum
weighted matching by augmenting any estimation routine for the size of an
unweighted matching. The algorithm is implementable in any streaming model
including dynamic graph streams. We also give the first constant estimation for
the maximum matching size in a dynamic graph stream for planar graphs (or any
graph with bounded arboricity) using space which also
extends to weighted matching. Using previous results by Kapralov, Khanna, and
Sudan (2014) we obtain a approximation for general graphs
using space in random order streams, respectively. In
addition, we give a space lower bound of for any
randomized algorithm estimating the size of a maximum matching up to a
factor for adversarial streams
Maximum likelihood estimation of photon number distribution from homodyne statistics
We present a method for reconstructing the photon number distribution from
the homodyne statistics based on maximization of the likelihood function
derived from the exact statistical description of a homodyne experiment. This
method incorporates in a natural way the physical constraints on the
reconstructed quantities, and the compensation for the nonunit detection
efficiency.Comment: 3 pages REVTeX. Final version, to appear in Phys. Rev. A as a Brief
Repor
Light particle spectra from 35 MeV/nucleon 12C-induced reactions on 197Au
Energy spectra for p, d, t, 3He, 4He, and 6He from the reaction 12C+197Au at 35 MeV/nucleon are presented. A common intermediate rapidity source is identified using a moving source fit to the spectra that yields cross sections which are compared to analogous data at other bombarding energies and to several different models. The excitation function of the composite to proton ratios is compared with quantum statistical, hydrodynamic, and thermal models
Robust and Generalisable Segmentation of Subtle Epilepsy-causing Lesions: a Graph Convolutional Approach
Focal cortical dysplasia (FCD) is a leading cause of drug-resistant focal
epilepsy, which can be cured by surgery. These lesions are extremely subtle and
often missed even by expert neuroradiologists. "Ground truth" manual lesion
masks are therefore expensive, limited and have large inter-rater variability.
Existing FCD detection methods are limited by high numbers of false positive
predictions, primarily due to vertex- or patch-based approaches that lack
whole-brain context. Here, we propose to approach the problem as semantic
segmentation using graph convolutional networks (GCN), which allows our model
to learn spatial relationships between brain regions. To address the specific
challenges of FCD identification, our proposed model includes an auxiliary loss
to predict distance from the lesion to reduce false positives and a weak
supervision classification loss to facilitate learning from uncertain lesion
masks. On a multi-centre dataset of 1015 participants with surface-based
features and manual lesion masks from structural MRI data, the proposed GCN
achieved an AUC of 0.74, a significant improvement against a previously used
vertex-wise multi-layer perceptron (MLP) classifier (AUC 0.64). With
sensitivity thresholded at 67%, the GCN had a specificity of 71% in comparison
to 49% when using the MLP. This improvement in specificity is vital for
clinical integration of lesion-detection tools into the radiological workflow,
through increasing clinical confidence in the use of AI radiological adjuncts
and reducing the number of areas requiring expert review.Comment: accepted at MICCAI 202
Quantum homodyne tomography with a priori constraints
I present a novel algorithm for reconstructing the Wigner function from
homodyne statistics. The proposed method, based on maximum-likelihood
estimation, is capable of compensating for detection losses in a numerically
stable way.Comment: 4 pages, REVTeX, 2 figure
Entanglement dynamics of three-qubit states in noisy channels
We study entanglement dynamics of the three-qubit system which is initially
prepared in pure Greenberger-Horne- Zeilinger (GHZ) or W state and transmitted
through one of the Pauli channels or the
depolarizing channel. With the help of the lower bound for three-qubit
concurrence we show that the W state preserves more entanglement than the GHZ
state in transmission through the Pauli channel . For the Pauli
channels and the depolarizing channel, however, the
entanglement of the GHZ state is more resistant against decoherence than the
W-type entanglement. We also briefly discuss how the accuracy of the lower
bound approximation depends on the rank of the density matrix under
consideration.Comment: 2 figures, 32 reference
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