Search results for "signal processing"

Electron Emission of Pt: Experimental Study and Comparison With Models in the Multipactor Energy Range

2016

Experimental data of secondary emission yield (SEY) and electron emission spectra of Pt under electron irradiation for normal incidence and primary energies lower than 1 keV are presented. Several relevant magnitudes, as total SEY, elastic backscattering probability, secondary emission spectrum, and backscattering coefficient, are given for different primary energies. These magnitudes are compared with theoretical or semiempirical formulas commonly used in the related literature.

Self-Organizing Architectures for Digital Signal Processing

2013

A New SOM Initialization Algorithm for Nonvectorial Data

2008

Self Organizing Maps (SOMs) are widely used mapping and clustering algorithms family. It is also well known that the performances of the maps in terms of quality of result and learning speed are strongly dependent from the neuron weights initialization. This drawback is common to all the SOM algorithms, and critical for a new SOM algorithm, the Median SOM (M-SOM), developed in order to map datasets characterized by a dissimilarity matrix. In this paper an initialization technique of M-SOM is proposed and compared to the initialization techniques proposed in the original paper. The results show that the proposed initialization technique assures faster learning and better performance in terms…

Measurement of the forward-backward asymmetry of e(+)e(-)-]z-]b(b)over-bar using prompt leptons and a lifetime tag

1995

The forward-backward asymmetry of the process e+e-→Z→b {Mathematical expression} has been measured using events collected by the DELPHI experiment during the 1991 and 1992 LEP runs. This data sample corresponded to 884 000 hadronic Z decays at a centre-of-mass energy {Mathematical expression}. The tagging of b-quark events was performed using two approaches; the first was based on the semileptonic decay channels b→X+μ and b→X+e, the second used a lifetime tag with jet-charge reconstruction. The results of these two methods were combined to give {Mathematical expression} With the semileptonic sample, the forward-backward asymmetry of the process e+e-→Z→ {Mathematical expression} was also mea…

Improved Upper Limit on the Neutrino Mass from a Direct Kinematic Method by KATRIN

2019

We report on the neutrino mass measurement result from the first four-week science run of the Karlsruhe Tritium Neutrino experiment KATRIN in spring 2019. Beta-decay electrons from a high-purity gaseous molecular tritium source are energy analyzed by a high-resolution MAC-E filter. A fit of the integrated electron spectrum over a narrow interval around the kinematic end point at 18.57 keV gives an effective neutrino mass square value of (−1.0−1.1+0.9) eV2. From this, we derive an upper limit of 1.1 eV (90% confidence level) on the absolute mass scale of neutrinos. This value coincides with the KATRIN sensitivity. It improves upon previous mass limits from kinematic measurements by almost a …

Approximation Properties of the Modified Stancu Operators

2017

ABSTRACTIn this article we construct a sequence of Stancu-type operators that are based on a function τ. This function is any function on [0,1] continuously differentiable ∞ times, such that τ(0) =...

The expansion $\star$ mod $\bar{o}(\hbar^4)$ and computer-assisted proof schemes in the Kontsevich deformation quantization

2019

The Kontsevich deformation quantization combines Poisson dynamics, noncommutative geometry, number theory, and calculus of oriented graphs. To manage the algebra and differential calculus of series of weighted graphs, we present software modules: these allow generating the Kontsevich graphs, expanding the noncommutative & x22c6;-product by using a priori undetermined coefficients, and deriving linear relations between the weights of graphs. Throughout this text we illustrate the assembly of the Kontsevich & x22c6;-product up to order 4 in the deformation parameter Already at this stage, the & x22c6;-product involves hundreds of graphs; expressing all their coefficients via 149 w…

Experimental approach for testing the uncoupling between cardiovascular variability series

2002

In cardiovascular variability analysis, the significance of the coupling between two series is commonly assessed by defining a zero level on the magnitude-squared coherence (MSC). Although the use of the conventional value of 0.5 does not consider the dependence of MSC estimates on the analysis parameters, a theoretical threshold Tt is available only for the weighted covariance (WC) estimator. In this study, an experimental threshold for zero coherence Te was derived by a statistical test from the sampling distribution of MSC estimated on completely uncoupled time series. MSC was estimated by the WC method (Parzen window, spectral bandwidth B = 0.015, 0.02, 0.025, 0.03 Hz) and by the parame…

Gradient Scheduling Algorithm for Fair Delay Guarantee in Logarithmic Pricing Scenario

2008

In this paper we propose a packet scheduling scheme for ensuring delay as a Quality of Service (QoS) requirement. For customers, fair service is given while optimizing revenue of the network service provider. Gradient type algorithm for updating the weights of a packet scheduler is derived from a revenue-based optimization problem in the logarithmic pricing scenario. Algorithm is simple to implement. We compared algorithm with optimal brute-force method. The weight updating procedure is independent on the assumption of the connection's statistical behavior, and therefore it is robust against erroneous estimates of statistics.

A Simulation Analysis for Assessing the Reliability of AC/DC Hybrid Microgrids - Part I: Underground Station and Car Parking

2021

This paper reports the results of a simulation study with the aim of evaluating the capability of two portions of a hybrid AC/DC MV/LV network of maintaining their operation in off-grid mode during the loss of the main AC grid due to a failure. In particular, the study aims to verify, in the case of islanded operation of the two microgrids, the continuity of the electricity service by exploiting the local generation plants, Energy Storage Systems (ESSs), and other flexible resources managed by suitable algorithms in different energy scenarios. The analysis was carried out considering two microgrids: an underground station and a car parking with Electric Vehicles (EVs). For assessing the per…