scholarly journals Power laws and phase transitions in heterogenous car following with reaction times

2021 ◽  
Vol 103 (3) ◽  
Author(s):  
A. Sai Venkata Ramana ◽  
Saif Eddin Jabari
Keyword(s):  
Phase Transitions ◽  
Reaction Times ◽  
Power Laws ◽  
Car Following

scholarly journals CORTICAL PHASE TRANSITIONS, NONEQUILIBRIUM THERMODYNAMICS AND THE TIME-DEPENDENT GINZBURG–LANDAU EQUATION

2012 ◽  
Vol 26 (06) ◽  
pp. 1250035 ◽  
Author(s):  
WALTER J. FREEMAN ◽  
ROBERTO LIVI ◽  
MASASHI OBINATA ◽  
GIUSEPPE VITIELLO
Keyword(s):  
Phase Transitions ◽  
Landau Equation ◽  
Power Laws ◽  
Time Dependent ◽  
Many Body ◽  
Ginzburg Landau ◽  
Ginzburg Landau Equation ◽  
Characteristic Space ◽  
The Many ◽  
The Brain

The formation of amplitude modulated and phase modulated assemblies of neurons is observed in the brain functional activity. The study of the formation of such structures requires that the analysis has to be organized in hierarchical levels, microscopic, mesoscopic, macroscopic, each with its characteristic space-time scales and the various forms of energy, electric, chemical, thermal produced and used by the brain. In this paper, we discuss the microscopic dynamics underlying the mesoscopic and the macroscopic levels and focus our attention on the thermodynamics of the nonequilibrium phase transitions. We obtain the time-dependent Ginzburg–Landau equation for the nonstationary regime and consider the formation of topologically nontrivial structures such as the vortex solution. The power laws observed in functional activities of the brain is also discussed and related to coherent states characterizing the many-body dissipative model of brain.

Linear Acceleration Car-Following Model Development and Validation

1998 ◽  
Vol 1644 (1) ◽  
pp. 10-19 ◽  
Author(s):  
M.F. Aycin ◽  
R.F. Benekohal
Keyword(s):  
Intelligent Transportation Systems ◽  
Field Data ◽  
Statistical Tests ◽  
Reaction Times ◽  
Linear Acceleration ◽  
Transportation Systems ◽  
Cruise Control ◽  
Vehicle Simulation ◽  
Car Following ◽  
Car Following Model

A linear acceleration car-following model has been developed for realistic simulation of traffic flow in intelligent transportation systems (ITS) applications. The new model provides continuous acceleration profiles instead of the stepwise profiles that are currently used. The brake reaction times of the drivers are simulated effectively and are independent of the simulation time steps. Chain-reaction times of the drivers are also simulated and perception thresholds are incorporated in the model. The preferred time headways are utilized to determine the simulated drivers’ separation during car-following. The features of the model and the realistic vehicle simulation in car-following and in stop-and-go conditions make this model suitable to ITS, especially to autonomous intelligent cruise-control systems. The car-following algorithm is validated at microscopic and macroscopic levels by using field data. Simulated versus field trajectories and statistical tests show very strong agreement between simulation results and field data.

Car-Following Model for Motorway Traffic

2005 ◽  
Vol 1934 (1) ◽  
pp. 33-42 ◽  
Author(s):  
Jiao Wang ◽  
Ronghui Liu ◽  
Frank Montgomery
Keyword(s):  
Shock Wave ◽  
Wave Propagation ◽  
Flow Characteristics ◽  
Reaction Times ◽  
Shock Wave Propagation ◽  
Flow Density ◽  
Model Parameters ◽  
Simulation Experiments ◽  
Car Following ◽  
Car Following Model

This paper presents a new car-following model that aims to capture some of the key motorway flow characteristics, namely, traffic breakdown, hysteresis, and shock wave propagation, as well as close-following behavior. The model proposes three different driving states: nonalert, alert, and close following. Under the different driving states, drivers apply different reaction times and accelerations. This paper presents the formulation and algorithmic implementation of the model. The theoretical analysis of the macroscopic flow–density relationships of the model is discussed. Simulation experiments were conducted, and the results are examined at both the macroscopic level (speed breakdown and traffic hysteresis) and the microscopic level (gap distribution and shock wave propagation). The results show that the model is able to capture realistically the speed drop, traffic hysteresis, and shock wave propagation as well as close-following behavior. Further studies of the sensitivities of key model parameters suggest that the drivers’ reaction times have a significant effect on the modeled capacity and occupancy, while the effect of the speed threshold that distinguishes congested from noncongested traffic flow is less significant.

Electron Microscopy of Graphite Intercalation Compounds

1982 ◽  
Vol 40 ◽  
pp. 544-545
Author(s):  
G. Timp ◽  
L. Salamanca-Riba ◽  
L.W. Hobbs ◽  
G. Dresselhaus ◽  
M.S. Dresselhaus
Keyword(s):  
Electron Microscopy ◽  
Phase Transitions ◽  
Domain Wall ◽  
Intercalation Compounds ◽  
Lattice Plane ◽  
Wall Model ◽  
Graphite Intercalation Compounds ◽  
Fundamental Symmetry ◽  
Graphite Intercalation

Electron microscopy can be used to study structures and phase transitions occurring in graphite intercalations compounds. The fundamental symmetry in graphite intercalation compounds is the staging periodicity whereby each intercalate layer is separated by n graphite layers, n denoting the stage index. The currently accepted model for intercalation proposed by Herold and Daumas assumes that the sample contains equal amounts of intercalant between any two graphite layers and staged regions are confined to domains. Specifically, in a stage 2 compound, the Herold-Daumas domain wall model predicts a pleated lattice plane structure.

Ultrastructural identification of three types of sensory setae on copepod antennae

1995 ◽  
Vol 53 ◽  
pp. 956-957
Author(s):  
T. M. Weatherby ◽  
P.H. Lenz
Keyword(s):  
Phase Locking ◽  
Membrane Surface ◽  
Reaction Times ◽  
High Sensitivity ◽  
Structural Features ◽  
Calanoid Copepods ◽  
Marine Food Webs ◽  
Dendritic Membrane ◽  
Ultrastructural Characterization

Crustaceans, as well as other arthropods, are covered with sensory setae and hairs, including mechanoand chemosensory sensillae with a ciliary origin. Calanoid copepods are small planktonic crustaceans forming a major link in marine food webs. In conjunction with behavioral and physiological studies of the antennae of calanoids, we undertook the ultrastructural characterization of sensory setae on the antennae of Pleuromamma xiphias.Distal mechanoreceptive setae exhibit exceptional behavioral and physiological performance characteristics: high sensitivity (<10 nm displacements), fast reaction times (<1 msec latency) and phase locking to high frequencies (1-2 kHz). Unusual structural features of the mechanoreceptors are likely to be related to their physiological sensitivity. These features include a large number (up to 3000) of microtubules in each sensory cell dendrite, arising from or anchored to electron dense rods associated with the ciliary basal body microtubule doublets. The microtubules are arranged in a regular array, with bridges between and within rows. These bundles of microtubules extend far into each mechanoreceptive seta and terminate in a staggered fashion along the dendritic membrane, contacting a large membrane surface area and providing a large potential site of mechanotransduction.

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