Search results for "Probability"

A Study of the Influence of Shadowing on the Statistical Properties of the Capacity of Mobile Radio Channels

2008

Article from the journal: Wireless Personal Communications The original publication is available at www.springerlink.com : http://dx.doi.org/10.1007/s11277-008-9545-7 This paper studies the influence of shadowing on the statistical properties of the channel capacity. The problem is addressed by using a Suzuki process as an appropriate statistical channel model for land mobile terrestrial channels. Using this model, exact solutions for the probability density function (PDF), cumulative distribution function (CDF), level-crossing rate (LCR), and average duration of fades (ADF) of the channel capacity are derived. The results are studied for different levels of shadowing, corresponding to diff…

Adaptive Tracking Control of Nonlinear Time-Varying Systems with Unknown Control Coefficients and Unknown Time-Varying Parameters

2019

This paper investigates the tracking control of a class of strict-feedback uncertain nonlinear systems in the presence of unknown signs of control coefficients and unknown time-varying parameters as well as unknown disturbances. A robust adaptive controller and a new decoupled backstepping approach to stability analysis are developed by constructing a new compensation scheme. By introducing a Nussbaum function and a new type of hyperbolic tangent function, the effects of unknown time-varying parameters and unknown control coefficients are effectively compensated. By using the decoupled backstepping technique, it is proved that under the proposed control, all closed-loop states are uniform u…

Josephson Traveling Wave Parametric Amplifiers as Non-Classical Light Source for Microwave Quantum Illumination

2021

Abstract Detection of low-reflectivity objects can be enriched via the so-called quantum illumination procedure. In order that this quantum procedure outperforms classical detection protocols, entangled states of microwave radiation are initially required. In this paper, we discuss the role of Josephson Traveling Wave Parametric Amplifiers (JTWPAs), based on circuit-QED components, as suitable sources of a two-mode squeezed vacuum state, a special signal-idler entangled state. The obtained wide bandwidth makes the JTWPA an ideal candidate for generating quantum radiation in quantum metrology and information processing applications.

Nonstationary response envelope probability densities of nonlinear oscillators

2006

The nonstationary random response of a class of lightly damped nonlinear oscillators subjected to Gaussian white noise is considered. An approximate analytical method for determining the response envelope statistics is presented. Within the framework of stochastic averaging, the procedure relies on the Markovian modeling of the response envelope process through the definition of an equivalent linear system with response-dependent parameters. An approximate solution of the associated Fokker-Planck equation is derived by resorting to a Galerkin scheme. Specifically, the nonstationary probability density function of the response envelope is expressed as the sum of a time-dependent Rayleigh dis…

Markova impulsu dinamiskās sistēmās bazētu kociklu robežteorēmas un stabilitāte

1998

Statistical Dependence and Independence

2005

Statistical dependence is a type of relation between different characteristics measured on the same units. At one extreme is deterministic dependence; at the other is statistical independence, where the distribution of one variable is the same for all levels of the other. With more than two variables, an important distinction is between marginal and conditional dependence. In many contexts, the degree of dependence may be summarized by a suitable measure of association, perhaps as part of a general model. Reference is made to graphical models. Keywords: association; correlation; marginal; conditional; exponential family; graphical Markov models

Evaluation of the effect of chance correlations on variable selection using Partial Least Squares -Discriminant Analysis

2013

Variable subset selection is often mandatory in high throughput metabolomics and proteomics. However, depending on the variable to sample ratio there is a significant susceptibility of variable selection towards chance correlations. The evaluation of the predictive capabilities of PLSDA models estimated by cross-validation after feature selection provides overly optimistic results if the selection is performed on the entire set and no external validation set is available. In this work, a simulation of the statistical null hypothesis is proposed to test whether the discrimination capability of a PLSDA model after variable selection estimated by cross-validation is statistically higher than t…

Soft variable structure controller design for singular systems

2015

Abstract A novel soft variable structure control (SVSC) scheme is addressed for a class of singular systems under I-controllable in this paper. The structural features of SVSC with differential equations are investigated. The stability of singular systems based on SVSC scheme is guaranteed by an equivalent characterization theory, and then a soft variable structure controller is designed. The concrete algorithm of SVSC with differential equations is proposed. The developed SVSC law for singular systems is carried out for the purpose of achieving rapid regulative rate, and shortening arrival time. Moreover, system chattering can be attenuated in the process of approaching to the equilibrium …

QSPR/QSAR Studies of 2-Furylethylenes Using Bond-Level Quadratic Indices and Comparison with Other Computational Approaches

2017

The recently introduced, non-stochastic and stochastic quadratic indices (Marrero-Ponce <em>et al. J. Comp. Aided Mol. Des.</em> 2006, 20, 685-701) were applied to QSAR/QSPR studies of heteroatomic molecules. These novel bond-based molecular descriptors (MDs) were used for the prediction of the partition coefficient (log P), and the antibacterial activity of 34 derivatives of 2-furylethylenes. Two statistically significant QSPR models using non-stochastic and stochastic bond-based quadratic indices were obtained (R<sup>2</sup> = 0.971, s = 0.137 and R<sup>2</sup> = 0.986, s = 0.096). These models showed good stability to data variation in leave-one-out (L…

The Potsdam Open Source Radio Interferometry Tool (PORT)

2021

The Potsdam Open Source Radio Interferometry Tool (PORT) is the very long baseline interferometry (VLBI) analysis software developed and maintained at the GFZ German Research Centre for Geosciences. Chiefly, PORT is tasked with the timely processing of VLBI sessions and post-processing activities supporting the generation of celestial and terrestrial reference frames. In addition, it serves as a framework for research and development within the GFZ's VLBI working group and is part of the tool set employed in educating young researchers. Starting out from VLBI group delays, PORT estimates station and radio sources positions, as well as Earth orientation parameters, tropospheric parameters, a…