Markov Perturbations on Large Time Intervals

1998 ◽  
pp. 161-211
Author(s):  
M. I. Freidlin ◽  
A. D. Wentzell
Keyword(s):  
Large Time ◽  
Time Intervals

Atomistic Simulations and Interfacial Morphology of Graphene Grown on SiC(0001) and SiC(000-1) Substrates

2016 ◽  
Vol 858 ◽  
pp. 1121-1124
Author(s):  
Antonino La Magna ◽  
Ioannis Deretzis ◽  
Filippo Giannazzo ◽  
Giuseppe Nicotra ◽  
Fabrizio Roccaforte ◽  
...  
Keyword(s):  
Large Time ◽  
Kinetic Monte Carlo ◽  
Hexagonal Lattice ◽  
Honeycomb Structure ◽  
Atomistic Simulations ◽  
Initial Surface ◽  
Time Intervals ◽  
Large Systems ◽  
Temperature And Pressure ◽  
The Individual

A Kinetic Monte Carlo scheme is applied to simulate with atomic resolution the synthesis of mono (few) layer(s) graphene (Gr) from a silicon carbide (SiC) substrate by selective evaporation of silicon (Si) atoms. The simulation computes the individual dynamics of the residual carbon (C) atoms which diffuse and reconfigure starting from the positions occupied in the SiC hexagonal lattice to the final Gr honeycomb structure. During the transition they gradually modify hybridization (from sp3 to sp2) and bond partners (from Si-C to C-C). We demonstrate that our method is able to recover the complex evolution steps of the epitaxial Gr on SiC in large systems for large time intervals. Moreover, the simulation results can be validated directly by means of comparison with experimental data when varying the material (e.g. initial surface configuration or polarity) or process (e.g. temperature and pressure) conditions.

Optimal control problems over large time intervals

Automatica ◽  
1987 ◽  
Vol 23 (3) ◽  
pp. 355-363 ◽  
Author(s):  
Brian D.O. Anderson ◽  
Petar V. Kokotovic
Keyword(s):  
Optimal Control ◽  
Large Time ◽  
Optimal Control Problems ◽  
Control Problems ◽  
Time Intervals

scholarly journals Tropospheric Volcanic SO2 Mass and Flux Retrievals from Satellite. The Etna December 2018 Eruption

2021 ◽  
Vol 13 (11) ◽  
pp. 2225
Author(s):  
Stefano Corradini ◽  
Lorenzo Guerrieri ◽  
Hugues Brenot ◽  
Lieven Clarisse ◽  
Luca Merucci ◽  
...  
Keyword(s):  
Large Time ◽  
Risk Mitigation ◽  
Test Case ◽  
Satellite Measurements ◽  
Time Intervals ◽  
So2 Flux ◽  
Volcanic Monitoring ◽  
Terra Modis ◽  
Higher Sensitivity ◽  
Good Agreement

The presence of volcanic clouds in the atmosphere affects air quality, the environment, climate, human health and aviation safety. The importance of the detection and retrieval of volcanic SO2 lies with risk mitigation as well as with the possibility of providing insights into the mechanisms that cause eruptions. Due to their intrinsic characteristics, satellite measurements have become an essential tool for volcanic monitoring. In recent years, several sensors, with different spectral, spatial and temporal resolutions, have been launched into orbit, significantly increasing the effectiveness of the estimation of the various parameters related to the state of volcanic activity. In this work, the SO2 total masses and fluxes were obtained from several satellite sounders—the geostationary (GEO) MSG-SEVIRI and the polar (LEO) Aqua/Terra-MODIS, NPP/NOAA20-VIIRS, Sentinel5p-TROPOMI, MetopA/MetopB-IASI and Aqua-AIRS—and compared to one another. As a test case, the Christmas 2018 Etna eruption was considered. The characteristics of the eruption (tropospheric with low ash content), the large amount of (simultaneously) available data and the different instrument types and SO2 columnar abundance retrieval strategies make this cross-comparison particularly relevant. Results show the higher sensitivity of TROPOMI and IASI and a general good agreement between the SO2 total masses and fluxes obtained from all the satellite instruments. The differences found are either related to inherent instrumental sensitivity or the assumed and/or calculated SO2 cloud height considered as input for the satellite retrievals. Results indicate also that, despite their low revisit time, the LEO sensors are able to provide information on SO2 flux over large time intervals. Finally, a complete error assessment on SO2 flux retrievals using SEVIRI data was realized by considering uncertainties in wind speed and SO2 abundance.

Considerations for determining the time course of post-activation potentiation

2015 ◽  
Vol 40 (11) ◽  
pp. 1163-1170 ◽  
Author(s):  
Maria L. Nibali ◽  
Dale W. Chapman ◽  
Robert A. Robergs ◽  
Eric J. Drinkwater
Keyword(s):  
Effect Size ◽  
Continuous Time ◽  
Time Course ◽  
Large Time ◽  
Time Interval ◽  
Single Trial ◽  
Time Intervals ◽  
Small Individual ◽  
Temporal Profile ◽  
Back Squat

We sought to determine the efficacy of using a continuous time course trial to assess the temporal profile of post-activation potentiation and to determine the time course of potentiation of discrete jump squat kinetic and kinematic variables. Eight physically trained men performed jump squats before and 4, 8, and 12 min after a 5-repetition maximum back squat. Time intervals were assessed in 3 discontinuous trials (each time interval assessed in a separate trial) and in 1 continuous trial (all time intervals assessed in a single trial). Percentage differences between continuous and discontinuous trials at each time interval were mostly insubstantial. Discrete variables displayed a diverse time course (effect size: trivial to large); time to maximal values ranged between 5.00 ± 2.53 min (concentric peak force) and 9.50 ± 2.98 min (eccentric mean force). Eccentric variables (8.58 ± 3.56 min) took longer to peak than concentric variables (6.64 ± 2.93 min) (effect size: small). Individual subjects attained maximal values for kinetic and kinematic variables at different time intervals, yet the 4-min interval typically displayed the greatest magnitude and frequency of potentiation. We conclude that a continuous time course trial does not substantially influence performance of subsequent jumps and is appropriate for determining the temporal profile of potentiation, which is influenced by discrete jump squat kinetic and kinematic variables and individual differences.

scholarly journals Non parabolic interface motion for the 1-D Stefan problem: Dirichlet boundary conditions

2017 ◽  
Vol 21 (6 Part A) ◽  
pp. 2327-2336 ◽  
Author(s):  
Ernesto Hernandez ◽  
José Otero ◽  
Rubén Santiago ◽  
Raúl Martinez ◽  
Francisco Castillo ◽  
...  
Keyword(s):  
Finite Difference ◽  
Boundary Conditions ◽  
Difference Scheme ◽  
Finite Difference Scheme ◽  
Large Time ◽  
Dirichlet Boundary Conditions ◽  
Time Intervals ◽  
Interface Motion ◽  
Interface Position ◽  
The Heat Balance

Over a finite 1-D specimen containing two phases of a pure substance, it has been shown that the liquid-solid interface motion exhibits parabolic behavior at small time intervals. We study the interface behavior over a finite domain with homogeneous Dirichlet boundary conditions for large time intervals, where the interface motion is not parabolic due to finite size effects. Given the physical nature of the boundary conditions, we are able to predict exactly the interface position at large time values. These predictions, which to the best of our knowledge, are not found in the literature, were confirmed by using the heat balance integral method of Goodman and a non-classical finite difference scheme. Using heat transport theory, it is shown as well, that the temperature profile within the specimen is exactly linear and independent of the initial profile in the asymptotic time limit. The physics of heat transport provides a powerful tool that is used to fine tune the numerical methods. We also found that in order to capture the physical behavior of the interface, it was necessary to develop a new non-classical finite difference scheme that approaches asymptotically to the predicted interface position. We offer some numerical examples where the predicted effects are illustrated, and finally we test our predictions with the heat balance integral method and the non-classical finite difference scheme by studying the liquid-solid phase transition in aluminum.

The random record model

1977 ◽  
Vol 356 (1687) ◽  
pp. 529-547 ◽  
Keyword(s):  
Point Process ◽  
Large Time ◽  
Asymptotic Properties ◽  
Fixed Interval ◽  
Independent Point ◽  
Time Intervals ◽  
Record Times ◽  
Index Numbers ◽  
Independent And Identically Distributed

This paper contains a detailed study of the random record model, which is the process of successive upper records in a sequence of independent and identically distributed variates occurring at the points of an independent point process. Asymptotic properties of the record and inter-record times, and of the number of records in a fixed interval, are derived, for both large time intervals and large record index numbers. A generalization which permits some dependence between the variates and the point process is also discussed, with emphasis on explicit results.

scholarly journals THE THERMODYNAMICS OF SOCIAL PROCESSES: THE TEEN BIRTH PHENOMENON

Fractals ◽  
2001 ◽  
Vol 09 (02) ◽  
pp. 193-208 ◽  
Author(s):  
NICOLA SCAFETTA ◽  
PATTI HAMILTON ◽  
PAOLO GRIGOLINI
Keyword(s):  
Statistical Analysis ◽  
Diffusion Process ◽  
Intensity Ratio ◽  
Large Time ◽  
Social Process ◽  
Social Processes ◽  
Time Intervals ◽  
Teen Birth ◽  
Teen Births ◽  
Stationary Diffusion

We argue that a process of social interest is a balance of order and randomness, thereby producing a departure from a stationary diffusion process. The strength of this departure effect vanishes if the order to randomness intensity ratio vanishes, and this property allows us to reveal, although in an indirect way, the existence of a finite order to randomness intensity ratio. We aim at detecting this effect. We introduce a method of statistical analysis alternative to the compression procedures, with which the limitations of the traditional Kolmogorov-Sinai (KS) approach are bypassed. We prove that this method makes it possible for us to build up a memory detector, which signals the presence of even very weak memory, provided that this is persistent over large time intervals. We apply the analysis to the study of the teen birth phenomenon and we find that the unmarried teen births are a manifestation of a social process with a memory more intense than that of the married teens. We attempt to give a social interpretation of this effect.

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