scholarly journals Step Bunches, Nanowires and Other Vicinal “Creatures”—Ehrlich–Schwoebel Effect by Cellular Automata

Crystals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1135
Author(s):  
Magdalena Załuska-Kotur ◽  
Hristina Popova ◽  
Vesselin Tonchev
Keyword(s):  
Crystal Growth ◽  
Cellular Automata ◽  
Cellular Automaton ◽  
Cellular Automaton Model ◽  
Proper Selection ◽  
Step Bunching ◽  
Surface Steps ◽  
Lower Terrace ◽  
Selection Of

Different patterns can be created on the surface of growing crystals, among which the step bunches and/or step meanders are two of the most studied. The Ehrlich–Schwoebel effect at the surface steps is considered one of the “usual suspects” of such patterning. A direct step barrier is when it is easier to attach a particle to the step from the lower terrace than from the upper terrace. Thus, during the process of crystal growth leads to the formation of meanders, while an inverse barrier leads to step bunching. Based on our vicinal Cellular Automaton model, but this time in (2 + 1)D, we show that the combination of a direct and inverse step barrier and the proper selection of the potential of the well between them leads to the formation of bunched step structures. Following this is the formation of anti-bands. In addition, changing the height of the direct step barrier leads to the growth of nanocolumns, nanowires, and nanopyramids or meanders, in the same system.

A Simple Three-States Cellular Automaton for Modelling Excitable Media

1998 ◽  
Vol 12 (05) ◽  
pp. 601-607 ◽  
Author(s):  
M. Andrecut
Keyword(s):  
Wave Propagation ◽  
Partial Differential Equations ◽  
Cellular Automata ◽  
Differential Equations ◽  
Cellular Automaton ◽  
Cellular Automaton Model ◽  
Excitable Media ◽  
Self Organization ◽  
Partial Differential ◽  
Bz Reaction

Wave propagation in excitable media provides an important example of spatiotemporal self-organization. The Belousov–Zhabotinsky (BZ) reaction and the impulse propagation along nerve axons are two well-known examples of this phenomenon. Excitable media have been modelled by continuous partial differential equations and by discrete cellular automata. Here we describe a simple three-states cellular automaton model based on the properties of excitation and recovery that are essential to excitable media. Our model is able to reproduce the dynamics of patterns observed in excitable media.

An Improved Cellular Automaton Model of Traffic Regulations and the Effect of Deceleration Probability

2014 ◽  
Vol 721 ◽  
pp. 62-65 ◽  
Author(s):  
Lu Chao Han
Keyword(s):  
Mathematical Model ◽  
Cellular Automata ◽  
Cellular Automaton ◽  
Traffic Flow ◽  
Cellular Automaton Model ◽  
Psychological State ◽  
Transportation Safety ◽  
Mathematical Form ◽  
Lane Changes ◽  
Traffic Rule

In order to evaluate the keep-right-except-to-pass traffic rule, which is in effect in most countries, a suitable mathematical model is necessary. With the help the following model, analysts can objectively evaluate the effects and benefits of various driving regulations and rules. We formalize the situation in which automobiles are being driven on a multi-lane freeway as a process of cellular automata (CA). Following the methods used in the studies of Kerner and Barlovic and using the NaSch model, we formalize the keep-right-except-to-pass rule into mathematical form. We set the driving strategy by adopting the Velocity-Dependent-Randomization (VDR) model, considering the driver’s psychological state with respect to his desire to slow down behind, or to pass, another automobile. Adding stochastic factors during the analysis of the driving process, we examined mathematically the effects of traffic flow, the utilization of lanes, and transportation safety which mostly depends on the frequency of lane changes, to evaluate the keep-right rule.

scholarly journals Simulation and Optimization of Ground Traffic on Airports using Cellular Automata

2018 ◽  
Vol 3 ◽  
Author(s):  
Florian Mazur ◽  
Michael Schreckenberg
Keyword(s):  
Cellular Automata ◽  
Cellular Automaton ◽  
Cellular Automaton Model ◽  
Simulation And Optimization ◽  
International Airport ◽  
Limited Space ◽  
Capacity Limit ◽  
Airport Ground Operations

Due to increasing numbers of airplane operations on international airports in Germany, the efficiency of airport-ground operations becomes more and more important. Some airports, such as the international airport of Duesseldorf, have reached their capacity limit and need major improvements in order to handle the continuously growing number of airplanes and passengers. Further expansion of the airport is not possible because of limited space. To improve airport-ground operations, simulations are useful for evaluating suggestions in advance and for avoiding poor planning. Therefore the CAMAT-Model was developed (Cellular Automaton Model for Airport Traffic), seeking to simulate the dynamics of all airplanes as realistically as possible. Improvements on the current layout can be simulated as well as new taxiways and new taxiing routes. In this paper, we present the new CAMAT-Model and give examples of possible improvements at the airport of Duesseldorf and their influence on average rolling times of airplanes.

scholarly journals TOWARDS A FRAMEWORK FOR INTUITIVE PROGRAMMING OF CELLULAR AUTOMATA

2009 ◽  
Vol 19 (01) ◽  
pp. 73-83 ◽  
Author(s):  
SAMI TORBEY
Keyword(s):  
Cellular Automata ◽  
Genetic Programming ◽  
Cellular Automaton ◽  
Parallel Computation ◽  
Automated Design ◽  
Cellular Automaton Model ◽  
Massively Parallel ◽  
Local Processing ◽  
Processing Elements ◽  
Global Behaviour

The ability to obtain complex global behaviour from simple local rules makes cellular automata an interesting platform for massively parallel computation. However, manually designing a cellular automaton to perform a given computation can be extremely difficult, and automated design techniques such as genetic programming have their limitations because of the absence of human intuition. In this paper, we propose elements of a framework whose goal is to make the manual synthesis of cellular automata rules exhibiting desired global characteristics more programmer-friendly, while maintaining the simplicity of local processing elements. Although many of the framework elements that we describe here are not new, we group them into a consistent framework and show that they can all be implemented on a traditional cellular automaton, which means that they are merely more human-friendly ways of describing simple cellular automata rules, and not foreign structures that require changing the traditional cellular automaton model.

A Study of the Keep-Right-Except-to-Pass Traffic Rule on Cellular Automata

2014 ◽  
Vol 989-994 ◽  
pp. 2470-2473
Author(s):  
Wen Bin Cao
Keyword(s):  
Cellular Automata ◽  
Cellular Automaton ◽  
Traffic Flow ◽  
Large Scale ◽  
Cellular Automaton Model ◽  
Driving Safety ◽  
Average Speed ◽  
Object A ◽  
Flow Through ◽  
Traffic Rule

Traffic rule is set to enable the safety and efficiency of the traffic. This paper takes the keep-right-except-to-pass rule as the research object. A three-lane cellular automaton model is proposed to simulate traffic flow. Through computer simulating, we analyze the relationships among traffic flow, overtaking ratio, average speed and density. The result shows that the rule although can increase the traffic flow and the average speed, the effect is not very evident, while this rule instead can increase driving safety in a large scale.

EVACUATION MODEL FOR EMERGENCY VEHICLES IN HIGHWAYS

2009 ◽  
Vol 20 (01) ◽  
pp. 59-69 ◽  
Author(s):  
NAJEM MOUSSA
Keyword(s):  
Cellular Automata ◽  
Cellular Automaton ◽  
Traffic Flow ◽  
Cellular Automaton Model ◽  
Emergency Vehicle ◽  
Lane Changing ◽  
Cellular Automata Model ◽  
Emergency Vehicles ◽  
Evacuation Model

In this paper, we propose a cellular automaton model for the evacuation of an emergency vehicle (EV) in highways. To facilitate the evacuation of the EV, some additional lane-changing rules (pull over of ordinary vehicles) are introduced in a two-lane cellular automata model for traffic flow in highway. We find that this pulling over of ordinary vehicles promotes a faster moving of the EV in traffic flow and minimize the EV's impact on the overall traffic.

A Study on Overtaking Taffic Rules in Two-Lane System Based on Cellular Automaton Model

2014 ◽  
Vol 644-650 ◽  
pp. 2479-2483
Author(s):  
Shuai Lu
Keyword(s):  
Cellular Automata ◽  
Cellular Automaton ◽  
Road Traffic ◽  
Highway Safety ◽  
Cellular Automaton Model ◽  
Highway Traffic ◽  
Traffic Capacity ◽  
Simulation Results ◽  
The Right ◽  
Traffic Rules

This paper studied three traffic rules under the situation of highway straight using the idea of cellular automata, and established the cellular automaton model of two-lane highway (situation of highway straight) for running but not allowing overtaking, the cellular automaton model of two-lane highway (situation of highway straight) for running on the right side and overtaking from the left side, and cellular automaton model of two-lane highway (situation of highway straight) for running on both sides and freely overtaking. This paper defines the concepts such as congestion probability, free passage probability, vehicles entering the highway probability, etc, in which, the congestion density is used to characterize the security of road traffic (the greater the congestion probability is, the less safety); free passage probability is used to evaluate the highway traffic capacity (the greater is the free passage probability, the better is the highway traffic capacity). Based on the simulation results, we can know about the two-lane freely overtaking rules have some effect in improving highway safety and traffic capacity.

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