A cellular automaton for the determination of the mean velocity of moving objects and its VLSI implementation

1996 ◽  
Vol 29 (4) ◽  
pp. 689-699 ◽  
Author(s):  
I. Karafyllidis ◽  
I. Andreadis ◽  
P. Tzionas ◽  
Ph. Tsalides ◽  
A. Thanailakis
Keyword(s):  
Cellular Automaton ◽  
Moving Objects ◽  
Vlsi Implementation ◽  
Mean Velocity ◽  
The Mean

The flow of liquid in a stream from the standard turbine impeller

1979 ◽  
Vol 44 (3) ◽  
pp. 700-710 ◽  
Author(s):  
Ivan Fořt ◽  
Hans-Otto Möckel ◽  
Jan Drbohlav ◽  
Miroslav Hrach
Keyword(s):  
Reynolds Number ◽  
Kinematic Viscosity ◽  
Momentum Flux ◽  
Relative Size ◽  
Mean Velocity ◽  
Axial Profile ◽  
The Mean ◽  
Hot Film ◽  
Turbine Impeller

Profiles of the mean velocity have been analyzed in the stream streaking from the region of rotating standard six-blade disc turbine impeller. The profiles were obtained experimentally using a hot film thermoanemometer probe. The results of the analysis is the determination of the effect of relative size of the impeller and vessel and the kinematic viscosity of the charge on three parameters of the axial profile of the mean velocity in the examined stream. No significant change of the parameter of width of the examined stream and the momentum flux in the stream has been found in the range of parameters d/D ##m <0.25; 0.50> and the Reynolds number for mixing ReM ##m <2.90 . 101; 1 . 105>. However, a significant influence has been found of ReM (at negligible effect of d/D) on the size of the hypothetical source of motion - the radius of the tangential cylindrical jet - a. The proposed phenomenological model of the turbulent stream in region of turbine impeller has been found adequate for values of ReM exceeding 1.0 . 103.

Prediction of the Maximum Number of Repetitions and Repetitions in Reserve From Barbell Velocity

2018 ◽  
Vol 13 (3) ◽  
pp. 353-359 ◽  
Author(s):  
Amador García-Ramos ◽  
Alejandro Torrejón ◽  
Belén Feriche ◽  
Antonio J. Morales-Artacho ◽  
Alejandro Pérez-Castilla ◽  
...  
Keyword(s):  
Body Mass ◽  
General Equation ◽  
Bench Press ◽  
Body Height ◽  
Strong Relationship ◽  
Training Set ◽  
Mean Velocity ◽  
The Mean ◽  
Acceptable Reliability

Purpose: To provide 2 general equations to estimate the maximum possible number of repetitions (XRM) from the mean velocity (MV) of the barbell and the MV associated with a given number of repetitions in reserve, as well as to determine the between-sessions reliability of the MV associated with each XRM. Methods: After determination of the bench-press 1-repetition maximum (1RM; 1.15 ± 0.21 kg/kg body mass), 21 men (age 23.0 ± 2.7 y, body mass 72.7 ± 8.3 kg, body height 1.77 ± 0.07 m) completed 4 sets of as many repetitions as possible against relative loads of 60%1RM, 70%1RM, 80%1RM, and 90%1RM over 2 separate sessions. The different loads were tested in a randomized order with 10 min of rest between them. All repetitions were performed at the maximum intended velocity. Results: Both the general equation to predict the XRM from the fastest MV of the set (CV = 15.8–18.5%) and the general equation to predict MV associated with a given number of repetitions in reserve (CV = 14.6–28.8%) failed to provide data with acceptable between-subjects variability. However, a strong relationship (median r2 = .984) and acceptable reliability (CV < 10% and ICC > .85) were observed between the fastest MV of the set and the XRM when considering individual data. Conclusions: These results indicate that generalized group equations are not acceptable methods for estimating the XRM–MV relationship or the number of repetitions in reserve. When attempting to estimate the XRM–MV relationship, one must use individualized relationships to objectively estimate the exact number of repetitions that can be performed in a training set.

Forward and Backward Running Waves in the Arteries: Analysis Using the Method of Characteristics

1990 ◽  
Vol 112 (3) ◽  
pp. 322-326 ◽  
Author(s):  
K. H. Parker ◽  
C. J. H. Jones
Keyword(s):  
Transient Flow ◽  
Impedance Analysis ◽  
Time Domain Analysis ◽  
Mean Velocity ◽  
One Dimensional ◽  
Acceleration And Deceleration ◽  
The Mean ◽  
The One ◽  
Made In

The one-dimensional equations of flow in the elastic arteries are hyperbolic and admit nonlinear, wavelike solutions for the mean velocity, U, and the pressure, P. Neglecting dissipation, the solutions can be written in terms of wavelets defined as differences of the Riemann invariants across characteristics. This analysis shows that the product, dUdP, is positive definite for forward running wavelets and negative definite for backward running wavelets allowing the determination of the net magnitude and direction of propagating wavelets from pressure and velocity measured at a point in the artery. With the linearizing assumption that intersecting wavelets are additive, the forward and backward running wavelets can be separately calculated. This analysis, applied to measurements made in the ascending aorta of man, shows that forward running wavelets dominate during both the acceleration and deceleration phases of blood flow in the aorta. The forward and backward running waves calculated using the linearized analysis are similar to the results of an impedance analysis of the data. Unlike the impedance analysis, however, this is a time domain analysis which can be applied to nonperiodic or transient flow.

scholarly journals Determination of the coefficient of inter-diffusion of gases and the velocity of ions under an electric force, in terms of mean free paths

1912 ◽  
Vol 86 (586) ◽  
pp. 197-206 ◽  
Keyword(s):  
Free Path ◽  
Equations Of Motion ◽  
Mean Free Path ◽  
Electric Force ◽  
Mean Velocity ◽  
The Mean ◽  
Definition Of ◽  
Good Agreement ◽  
Diffusion Of Gases

1. The properties of gases which depend on the velocity of agitation of molecules and the lengths of their free paths may easily be expressed in terms of the mean velocity of agitation and the mean free path when certain assumptions are made in order to simplify the investigations. The expressions thus found on the principles of the kinetic theory are in good agreement with the experimental results in most cases, but the formulæ that have been obtained for the coefficient of inter-diffusion of gases and the velocity of particles acted on by an external force are not so satisfactory. The equations of motion of two inter-diffusing gases have been given by Maxwell, and it may be shown from these that the exact value of the ratio of the coefficient of diffusion of ions to the velocity under unit electric force is N e /II, where N is the number of molecules per cubic centimetre of a gas at pressure II, and e the charge on an ion. The method adopted by Maxwell is perfectly general, there are no assumptions made as to the distribution of the velocities of agitation, and no particular definition of a collision of a free path is involved, so that there can be little doubt as to the accuracy of the result.

scholarly journals Biases in the estimation of velocity dispersions and dynamical masses for galaxy clusters

2020 ◽  
Vol 228 ◽  
pp. 00011
Author(s):  
A. Ferragamo ◽  
J.A. Rubiño-Martín ◽  
J. Betancort-Rijo ◽  
E. Munari ◽  
B. Sartoris ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Galaxy Clusters ◽  
Velocity Dispersion ◽  
Mean Velocity ◽  
Dynamical Mass ◽  
Unbiased Estimators ◽  
The Mean ◽  
Velocity Dispersions ◽  
Dynamical Masses

Using a set of 73 numerically simulated galaxy clusters, we have characterised the statistical and physical biases for three velocity dispersion and mass estimators, namely biweight, gapper and standard deviation, in the small number of galaxies regime (Ngal ≤ 75), both for the determination of the velocity dispersion and the dynamical mass of the clusters via the σ–M relation. These results are used to define a new set of unbiased estimators, that are able to correct for those statistical biases. By applying these new estimators to a subset of simulated observations, we show that they can retrieve bias-corrected values for both the mean velocity dispersion and the mean mass.

Evaluation of Debris Transport Augmentation by Turbulence During the Recirculation Cooling Phase of a LOCA

2012 ◽  
Author(s):  
Jong-Pil Park ◽  
Kyung Sik Choi ◽  
Ji Hwan Jeong ◽  
Jae Jun Jeong
Keyword(s):  
Considerable Increase ◽  
Cfd Analysis ◽  
Mean Velocity ◽  
Debris Transport ◽  
Turbulence Effect ◽  
Cooling Phase ◽  
The Mean ◽  
Cfd Analyses

The determination of the debris transport fraction during a LOCA of a PWR is very important in the sizing of the sump screen area. In this study, the debris transport fraction during the recirculation cooling phase is evaluated with and without consideration of turbulence effect. To do this, first experiments involving tumbling velocities measurements and supplementary CFD analyses are performed to verify the turbulence effect on debris transport. From these findings, the turbulence effect on the degree of debris tumbling augmentation was found to be represented by the algebraic sum of the mean velocity and the fluctuating velocity. Then, a CFD analysis of the flooding containment floor during the recirculation cooling phase of the OPR1000 plant is performed. Based on these studies, the debris transport fraction is evaluated for NUKON. The result shows a considerable increase in the debris transport fraction when a turbulence effect is implemented compared to when it is not. Increases of 5.55 and 2.06 times are observed for large NUKON and small/fine NUKON, respectively. This result implies that the turbulence effect should be considered in the debris transport quantification for conservatism.

Rapid Granular Flow Down Inclines

1994 ◽  
Vol 47 (6S) ◽  
pp. S240-S244 ◽  
Author(s):  
James T. Jenkins
Keyword(s):  
New York ◽  
Free Surface ◽  
Granular Flow ◽  
Academic Press ◽  
Mean Velocity ◽  
Fluctuation Velocity ◽  
Dense Flows ◽  
The Mean ◽  
Collisional Regime

As an example of the activity in the field of rapid granular flow, we sketch an analysis of a rapid granular flow of identical frictionless spheres that is driven by gravity down an incline. The flow is assumed to be dense, collisional, steady, and fully developed. Because we employ conditions at the base of the flow that are appropriate for a bumpy, frictionless boundary, the analysis is slightly more complicated than that of Savage (1983a, in Theory of Dispersed Multiphase Flow, RE Meyer (ed), Academic Press, New York, 339-358). Because we restrict our attention to dense flows, it is somewhat simpler than that of Richman and Marciniec (1990, J Appl Mech57, 1036-1043). It is essentially that of the dense collisional regime considered by Anderson and Jackson (1992, J Fluid Mech241, 145-168). We outline the determination of the profiles of the mean velocity, fluctuation velocity, and concentration through the depth of the flow and indicate how the boundary conditions provide relations between the depth of the flow, the angle of inclination, the fluctuation velocity at the base of the flow, and the mean velocity at the free surface.

RANS Predictions in an Idealized Lower-Plenum Model

2006 ◽  
Author(s):  
Joshua D. Hodson ◽  
Robert E. Spall ◽  
Barton L. Smith
Keyword(s):  
Stokes Equations ◽  
Turbulence Models ◽  
Navier Stokes ◽  
Mean Velocity ◽  
Navier Stokes Equations ◽  
Pressure Losses ◽  
Pressure Loss Coefficient ◽  
The Mean ◽  
Recirculation Length

The two-dimensional, unsteady, Reynolds-averaged Navier-Stokes equations have been solved for the flow across a row of confined cylinders with a pitch-to-diameter ratio of 1.7, a configuration which was designed to model a next generation nuclear plant lower-plenum. Four different turbulence models were used: k–ε, k–ω, v2–f, and differential Reynolds-stress transport. Comparisons with available experimental data were made for pressure losses, recirculation lengths, and mean velocity profiles. The results indicate that all models did a reasonable job of predicting the pressure loss coefficient. However, in terms of the mean velocities and recirculation length, the determination of which model performed best is not clear.

Determination of the mean velocity of a molecule

2003 ◽  
Vol 71 (3) ◽  
pp. 267-268
Author(s):  
Salvatore Ganci
Keyword(s):  
Mean Velocity ◽  
The Mean
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