Numerical loading of a Maxwellian probability distribution function

2003 ◽  
Vol 81 (8) ◽  
pp. 989-996 ◽  
Author(s):  
J L.V Lewandowski
Keyword(s):  
Distribution Function ◽  
Probability Distribution ◽  
Nonlinear Equations ◽  
Probability Distribution Function ◽  
Low Noise ◽  
Electron Dynamics ◽  
Renormalization Procedure ◽  
Particle In Cell ◽  
Velocity Moments ◽  
52.35 Py

A renormalization procedure for the numerical loading of a Maxwellian probability distribution function (PDF) is formulated. The procedure, which involves the solution of three coupled nonlinear equations, yields a numerically loaded PDF with improved properties for higher velocity moments. This method is particularly useful for low-noise particle-in-cell simulations with electron dynamics. PACS Nos.: 52.35.Py, 52.30.Jb, 52.55.Fa

AN ANALYTICAL SOLUTION FOR THE STOCHASTIC MODEL OF A TURBULENT CASCADE

2006 ◽  
Vol 20 (20) ◽  
pp. 1247-1251 ◽  
Author(s):  
A. A. MASOUDI ◽  
P. AZIMI ANARAKI
Keyword(s):  
Distribution Function ◽  
Probability Distribution ◽  
Analytical Solution ◽  
Stochastic Model ◽  
Langevin Equation ◽  
Probability Distribution Function ◽  
Operator Method ◽  
Planck Equation ◽  
Velocity Moments ◽  
Turbulent Cascade

In this paper we are going to derive the Fokker–Planck equation (FPE) which is based on the Langevin equation for the stochastic model of a turbulent cascade and then we exactly solve the FPE for a certain case and find an explicit form of the probability distribution function (PDF) by the operator method. Finally, by using this PDF, we calculate the velocity moments for this system.

scholarly journals Position-dependent matter density probability distribution function

2020 ◽  
Vol 102 (12) ◽  
Author(s):  
Drew Jamieson ◽  
Marilena Loverde
Keyword(s):  
Distribution Function ◽  
Probability Distribution ◽  
Probability Distribution Function ◽  
Matter Density

scholarly journals An Online Application for ΔR Calculation

Radiocarbon ◽  
2016 ◽  
Vol 59 (5) ◽  
pp. 1623-1627 ◽  
Author(s):  
Ron W Reimer ◽  
Paula J Reimer
Keyword(s):  
Distribution Function ◽  
Probability Distribution ◽  
Calibration Curve ◽  
Probability Distribution Function ◽  
Museum Collections ◽  
Online Program ◽  
Online Application ◽  
Radiocarbon Calibration

AbstractA regional offset (ΔR) from the marine radiocarbon calibration curve is widely used in calibration software (e.g. CALIB, OxCal) but often is not calculated correctly. While relatively straightforward for known-age samples, such as mollusks from museum collections or annually banded corals, it is more difficult to calculate ΔR and the uncertainty in ΔR for 14C dates on paired marine and terrestrial samples. Previous researchers have often utilized classical intercept methods that do not account for the full calibrated probability distribution function (pdf). Recently, Soulet (2015) provided R code for calculating reservoir ages using the pdfs, but did not address ΔR and the uncertainty in ΔR. We have developed an online application for performing these calculations for known-age, paired marine and terrestrial 14C dates and U-Th dated corals. This article briefly discusses methods that have been used for calculating ΔR and the uncertainty and describes the online program deltar, which is available free of charge.

scholarly journals Optimal Taylor–Couette turbulence

2012 ◽  
Vol 706 ◽  
pp. 118-149 ◽  
Author(s):  
Dennis P. M. van Gils ◽  
Sander G. Huisman ◽  
Siegfried Grossmann ◽  
Chao Sun ◽  
Detlef Lohse
Keyword(s):  
Distribution Function ◽  
Probability Distribution ◽  
Angular Velocity ◽  
Probability Distribution Function ◽  
Neutral Line ◽  
Velocity Ratio ◽  
Outer Cylinder ◽  
Taylor Number ◽  
Counter Rotation ◽  
Taylor Couette

AbstractStrongly turbulent Taylor–Couette flow with independently rotating inner and outer cylinders with a radius ratio of $\eta = 0. 716$ is experimentally studied. From global torque measurements, we analyse the dimensionless angular velocity flux ${\mathit{Nu}}_{\omega } (\mathit{Ta}, a)$ as a function of the Taylor number $\mathit{Ta}$ and the angular velocity ratio $a= \ensuremath{-} {\omega }_{o} / {\omega }_{i} $ in the large-Taylor-number regime $1{0}^{11} \lesssim \mathit{Ta}\lesssim 1{0}^{13} $ and well off the inviscid stability borders (Rayleigh lines) $a= \ensuremath{-} {\eta }^{2} $ for co-rotation and $a= \infty $ for counter-rotation. We analyse the data with the common power-law ansatz for the dimensionless angular velocity transport flux ${\mathit{Nu}}_{\omega } (\mathit{Ta}, a)= f(a)\hspace{0.167em} {\mathit{Ta}}^{\gamma } $, with an amplitude $f(a)$ and an exponent $\gamma $. The data are consistent with one effective exponent $\gamma = 0. 39\pm 0. 03$ for all $a$, but we discuss a possible $a$ dependence in the co- and weakly counter-rotating regimes. The amplitude of the angular velocity flux $f(a)\equiv {\mathit{Nu}}_{\omega } (\mathit{Ta}, a)/ {\mathit{Ta}}^{0. 39} $ is measured to be maximal at slight counter-rotation, namely at an angular velocity ratio of ${a}_{\mathit{opt}} = 0. 33\pm 0. 04$, i.e. along the line ${\omega }_{o} = \ensuremath{-} 0. 33{\omega }_{i} $. This value is theoretically interpreted as the result of a competition between the destabilizing inner cylinder rotation and the stabilizing but shear-enhancing outer cylinder counter-rotation. With the help of laser Doppler anemometry, we provide angular velocity profiles and in particular identify the radial position ${r}_{n} $ of the neutral line, defined by $ \mathop{ \langle \omega ({r}_{n} )\rangle } \nolimits _{t} = 0$ for fixed height $z$. For these large $\mathit{Ta}$ values, the ratio $a\approx 0. 40$, which is close to ${a}_{\mathit{opt}} = 0. 33$, is distinguished by a zero angular velocity gradient $\partial \omega / \partial r= 0$ in the bulk. While for moderate counter-rotation $\ensuremath{-} 0. 40{\omega }_{i} \lesssim {\omega }_{o} \lt 0$, the neutral line still remains close to the outer cylinder and the probability distribution function of the bulk angular velocity is observed to be monomodal. For stronger counter-rotation the neutral line is pushed inwards towards the inner cylinder; in this regime the probability distribution function of the bulk angular velocity becomes bimodal, reflecting intermittent bursts of turbulent structures beyond the neutral line into the outer flow domain, which otherwise is stabilized by the counter-rotating outer cylinder. Finally, a hypothesis is offered allowing a unifying view and consistent interpretation for all these various results.

Calculation of APD impulse response using a space- and time-dependent ionization probability distribution function

2003 ◽  
Vol 21 (1) ◽  
pp. 155-159 ◽  
Author(s):  
C.H. Tan ◽  
P.J. Hambleton ◽  
J.P.R. David ◽  
R.C. Tozer ◽  
G.J. Rees
Keyword(s):  
Distribution Function ◽  
Probability Distribution ◽  
Impulse Response ◽  
Probability Distribution Function ◽  
Ionization Probability ◽  
Time Dependent ◽  
Space And Time

Audio feature extraction using probability distribution function

2015 ◽  
Author(s):  
Suhaib A. ◽  
Khairunizam Wan ◽  
Azri A. Aziz ◽  
D. Hazry ◽  
Zuradzman M. Razlan ◽  
...  
Keyword(s):  
Feature Extraction ◽  
Distribution Function ◽  
Probability Distribution ◽  
Probability Distribution Function ◽  
Audio Feature ◽  
Audio Feature Extraction

Estimation of joint trace length probability distribution function in igneous, sedimentary, and metamorphic rocks

2013 ◽  
Vol 7 (6) ◽  
pp. 2353-2361 ◽  
Author(s):  
Jamal Zadhesh ◽  
Seyed-Mohammad Esmaeil Jalali ◽  
Ahmad Ramezanzadeh
Keyword(s):  
Distribution Function ◽  
Probability Distribution ◽  
Probability Distribution Function ◽  
Metamorphic Rocks ◽  
Trace Length
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