A high-speed self-similar ATM VBR traffic generator

2002 ◽  
Author(s):  
P. Droz ◽  
J.-Y. Le Boudec
Keyword(s):  
High Speed ◽  
Traffic Generator ◽  
Self Similar

An experimental investigation of incipient spilling breakers

2009 ◽  
Vol 633 ◽  
pp. 271-283 ◽  
Author(s):  
J. D. DIORIO ◽  
X. LIU ◽  
J. H. DUNCAN
Keyword(s):  
Wave Breaking ◽  
High Speed ◽  
Phase Speed ◽  
Breaking Waves ◽  
Front Face ◽  
Geometrical Parameters ◽  
Instability Mechanism ◽  
Scaling Relationships ◽  
Self Similar ◽  
Spilling Breakers

In the present paper, the profiles of incipient spilling breaking waves with wavelengths ranging from 10 to 120cm were studied experimentally in clean water. Short-wavelength breakers were generated by wind, while longer-wavelength breakers were generated by a mechanical wavemaker, using either a dispersive focusing or a sideband instability mechanism. The crest profiles of these waves were measured with a high-speed cinematic laser-induced fluorescence technique. For all the wave conditions reported herein, wave breaking was initiated with a capillary-ripple pattern as described in Duncan et al. (J. Fluid Mech., vol. 379, 1999, pp. 191–222). In the present paper, it is shown that at incipient breaking the crest shape is self-similar with two geometrical parameters that depend only on the slope of a particular point on the front face of the gravity wave. The scaling relationships appear to be universal for the range of wavelengths studied herein and hold for waves generated by mechanical wavemakers and by wind. The slope measure is found to be dependent on the wave phase speed and the rate of growth of the crest height prior to incipient breaking.

scholarly journals The Associative Multifractal Process: A Novel Model for Computer Network Traffic Flows

2021 ◽  
Author(s):  
Ginno Millán ◽  
Gastón Lefranc ◽  
Román Osorio-Comparán
Keyword(s):  
Mathematical Model ◽  
Time Series ◽  
High Speed ◽  
Computer Network ◽  
Traffic Flows ◽  
Multifractal Formalism ◽  
Proposed Model ◽  
Self Similar ◽  
Speed Computer ◽  
Novel Model

A novel constructive mathematical model based on the multifractal formalism in order to accurately characterizing the localized fluctuations present in the course of traffic flows today high-speed computer networks is presented. The proposed model has the target to analyze self-similar second-order time series representative of traffic flows in terms of their roughness and impulsivity.

scholarly journals A simple multifractal model for self-similar traffic flows in high-speed computer networks

2021 ◽  
Author(s):  
Ginno Millán
Keyword(s):  
High Speed ◽  
Process Models ◽  
Traffic Modeling ◽  
Traffic Flows ◽  
Markov Modulated Poisson Process ◽  
Traffic Trace ◽  
Self Similar ◽  
Markov Modulated ◽  
Speed Computer ◽  
Fitting Model

This paper presents a simple and fast technique of multifractal traffic modeling. It proposes a method of fitting model to a given traffic trace. A comparison of simulation results obtained for an exemplary trace, multifractal model and Markov Modulated Poisson Process models has been performed.

Coherent Structures and Correlation Fields in the Mixing Transition of a Turbulent Round Free Jet

2018 ◽  
Author(s):  
Benedikt Krohn ◽  
Sunming Qin ◽  
Victor Petrov ◽  
Annalisa Manera
Keyword(s):  
Coherent Structures ◽  
High Speed ◽  
Near Field ◽  
The Self ◽  
Turbulent Shear ◽  
Past Century ◽  
Self Similarity ◽  
Free Jet ◽  
Similar Region ◽  
Self Similar

Turbulent free jets attracted the focus of many scientists within the past century regarding the understanding of mass- and momentum transport in the turbulent shear field, especially in the near-field and the self-similar region. Recent investigations attempt to understand the intermediate fields, called the mixing transition or ‘the route to self-similarity’. An apparent gap is recognized in light of this mixing transition, with two main conjectures being put forth. Firstly the flow will always asymptotically reach a fully self-similar state if boundary conditions permit. The second proposes partial and local self-similarity within the mixing transition. We address the later with an experimental investigation of the intermediate field turbulence dynamics in a non-confined free jet with a nozzle diameter of 12.7 mm and an outer scale Reynolds number of 15,000. High speed Particle Image Velocimetry (PIV) is used to record the velocity fields with a final spatial resolution of 194 × 194 μm2. The analysis focuses on higher order moments and two-point correlations of velocity variances in space and time. We observed local self-similarity in the measured correlation fields. Coherent structures are present within the near-field where the turbulent energy spectrum cascades along a dissipative slope. Towards the transition region, the spectrum smoothly transforms to a viscous cascade, as it is commonly observed in the self-similar region.

Two Fracture Dynamics Problems of Fiber Reinforced Ceramics

2012 ◽  
Vol 512-515 ◽  
pp. 955-958
Author(s):  
Nian Chun Lü ◽  
Yun Hong Cheng ◽  
Jin Li Ji
Keyword(s):  
High Speed ◽  
Fiber Reinforced ◽  
Dynamic Stress Intensity Factors ◽  
Fracture Dynamics ◽  
Self Similar ◽  
Bridging Fibers ◽  
Concrete Solution ◽  
Dynamics Problems ◽  
Fracture Dynamics Problems ◽  
Superposition Theorem

After fiber reinforced ceramics occur a crack, its bridging fibers must engender, moreover the crack usually runs in the format of similarity. In order to analyze easily dynamic problems of fiber reinforced ceramics, bridging fiber segment is substituted for loads. When a crack moves at high speed, its fibers will break continuously. By application of the built dynamic model and the ways of self-similar functions, analytical solutions of the displacements, stresses and dynamic stress intensity factors under the action of a running increasing force Px2/t2 and a motive unit step load, respectively, can be gained, and it is also used to attain the concrete solution by means of superposition theorem.

Meandering due to large eddies and the statistically self-similar dynamics of quasi-two-dimensional jets

2012 ◽  
Vol 692 ◽  
pp. 347-368 ◽  
Author(s):  
Julien R. Landel ◽  
C. P. Caulfield ◽  
Andrew W. Woods
Keyword(s):  
Vertical Velocity ◽  
High Speed ◽  
Turbulent Jets ◽  
Theoretical Models ◽  
Maximum Speed ◽  
Two Dimensional ◽  
The Core ◽  
Self Similar ◽  
The Mean ◽  
Large Eddies

AbstractWe investigate experimentally the structure of quasi-two-dimensional plane turbulent jets discharged vertically from a slot of width $d$ into a fluid confined between two relatively close rigid boundaries with gap $W\ensuremath{\sim} O(d)$. At large vertical distances $z\gg W$ the jet structure consists of a meandering core with large counter-rotating eddies, which develop on alternate sides of the core. Using particle image velocimetry, we observe an inverse cascade typical of quasi-two-dimensional turbulence where both the core and the eddies grow linearly with $z$ and travel at an average speed proportional to ${z}^{\ensuremath{-} 1/ 2} $. However, although the present study concerns quasi-two-dimensional confined jets, the jets are self-similar and the mean properties are consistent with both experimental results and theoretical models of the time-averaged properties of fully unconfined planar two-dimensional jets. We believe that the dynamics of the interacting core and large eddies accounts for the Gaussian profile of the mean vertical velocity as shown by the spatial statistical distribution of the core and eddy structure. The lateral excursions (caused by the propagating eddies) of this high-speed central core produce a Gaussian distribution for the time-averaged vertical velocity. In addition, we find that approximately 75 % of the total momentum flux of the jet is contained within the core. The eddies travel substantially slower (at approximately 25 % of the maximum speed of the core) at each height and their growth is primarily attributed to entrainment of ambient fluid. The frequency of occurrence of the eddies decreases in a stepwise manner due to merging, with a well-defined minimum value of the corresponding Strouhal number $\mathit{St}\geq 0. 07$.

scholarly journals A Simple Multifractal Model for Self-Similar Traffic Flows in High-Speed Computer Networks

2021 ◽  
Author(s):  
Ginno Millán
Keyword(s):  
High Speed ◽  
Process Models ◽  
Traffic Modeling ◽  
Traffic Flows ◽  
Markov Modulated Poisson Process ◽  
Traffic Trace ◽  
Self Similar ◽  
Markov Modulated ◽  
Speed Computer ◽  
Fitting Model

This paper presents a simple and fast technique of multifractal traffic modeling. It proposes a method of fitting model to a given traffic trace. A comparison of simulation results obtained for an exemplary trace, multifractal model and Markov Modulated Poisson Process models has been performed.

Sign in / Sign up

Export Citation Format

Share Document