Results 241 to 250 of about 106,171 (271)

Projected spin wave theory. I. Diagrammatic evaluation of the kinematical interaction

Journal of Physics C: Solid State Physics, 1985
The evaluation at T=0 of the kinematical effects in the spin wave theory for S=1/2 Heisenberg ferro- and antiferromagnets has been achieved, projecting out the nonphysical magnonic contribution following Herbert's method. Moreover, the projected average value has been generalised to any operator and extended to any number of projection operators by ...
L M Floria, R Navarro
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Kinematic wave theory of bottlenecks of varying capacity

Mathematical Proceedings of the Cambridge Philosophical Society, 1956
ABSTRACTThis paper discusses a problem in traffic flow by the method of kinematic waves developed by Lighthill and Whitham(1,2). The theory of kinematic waves introduced by Lighthill and Whitham has been extended here to include the case when the flow q varies with the time, and it is seen that the expression for the wave velocity is of the same form ...
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Application of the theory of kinematic waves to the centrifugation of suspensions

Ingenieur-Archiv, 1983
The settling of solid particles in a liquid due to centrifugal force is described by using the equations of one-dimensional unsteady two-phase flow. By neglecting the acceleration terms the momentum equation can be reduced to a functional relationship between the dependant variables of the problem (volumetric concentration α of the solid particles and ...
G. Anestis, W. Schneider
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Kinematical theory of spiral waves in excitable media: Comparison with numerical simulations

Physica D: Nonlinear Phenomena, 1991
zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Mikhajlov, A. S., Zykov, V. S.
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On kinematic waves II. A theory of traffic flow on long crowded roads

Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences, 1955
This paper uses the method of kinematic waves, developed in part I, but may be read independently. A functional relationship between flow and concentration for traffic on crowded arterial roads has been postulated for some time, and has experimental backing (§2). From this a theory of the propagation of changes in traffic distribution along these roads
Lighthill, M. J., Whitham, G. B.
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A kinematic wave theory of multi-commodity network traffic flow

Transportation Research Part B: Methodological, 2012
Abstract A systematic understanding of traffic dynamics on road networks is crucial for many transportation studies and can help to develop more efficient ramp metering, evacuation, signal control, and other management and control strategies. In this study, we present a theory of multi-commodity network traffic flow based on the Lighthill–Whitham ...
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A simplified theory of kinematic waves in highway traffic, part I: General theory

Transportation Research Part B: Methodological, 1993
Abstract In the theory of “kinematic waves,” as described originally by Lighthill and Whitham in 1955, the evaluation of the shock path is typically rather tedious. Instead of using this theory to evaluate flows or densities, one can use it to evaluate the cumulative flow A ( x , t ) past any point x by time t .
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Macroscopic Modeling Framework Unifying Kinematic Wave Modeling and Three-Phase Traffic Theory

Transportation Research Record: Journal of the Transportation Research Board, 2008
Modeling breakdown probabilities or phase-transition probabilities is an important issue when assessing and predicting the reliability of traffic flow operations. Looking at empirical spatiotemporal patterns, these probabilities clearly are a function not only of the local prevailing traffic conditions (density, speed) but also of time and space.
Serge P. Hoogendoorn, Hans van Lint, Victor L. Knoop   +2 more
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The application of kinematic wave theory to wave trains and packets with small dissipation

The Physics of Fluids, 1982
The validity of kinematic wave theory for linear waves with small dissipation propagating through a homogeneous medium is examined with the aid of the higher-order theory of Chin. It is shown that both for nondissipative and weakly-dissipative waves the kinematic theory holds with errors of order ε2 for times of order ε−1 times the wave period, where ε
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A variational formulation of kinematic waves: basic theory and complex boundary conditions

Transportation Research Part B: Methodological, 2005
Abstract This paper proves that the solution of every well-posed kinematic wave (KW) traffic problem with a concave flow-density relation is a set of least-cost (shortest) paths in space-time with a special metric. The equi-cost contours are the vehicle trajectories. If the flow-density relation is strictly concave the set of shortest paths is unique
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