In this paper we lay the groundwork for gauging the level of safety of any type of traffic flow on a freeway, based on data from single loop detectors; the procedure can be implemented wherever such data are monitored or simulated. Our analyses are based on loop detector data for each of the freeway lanes for a short period of time preceding teach of over 1700 accidents in our case study. This ...

Accurate freeway travel time estimates are critical for transportation management and traveler information—both infrastructure-based and in-vehicle. Infrastructure managers are interested in estimating optimal freeway sensor density for new construction and retrofits. This paper describes a concept developed from first principles of traffic flow for establishing optimal sensor density based on ...

Explosive volcanic super-eruptions of several hundred cubic kilometres or more generate long run-out pyroclastic density currents the dynamics of which are poorly understood and controversial. Deposits of one such event in the southwestern USA, the 18.8 Ma Peach Spring Tuff, were formed by pyroclastic flows that travelled >170 km from the eruptive centre and entrained blocks up to ∼ 70-90 cm di...

The governing equations of a transversely isotropic dissipative medium are solved analytically to obtain the surface wave solutions. The appropriate solutions satisfy the required boundary conditions at the stress-free surface to obtain the frequency equation of Rayleigh wave. The numerical values of the non-dimensional speed of Rayleigh wave speed are computed for different values of frequency...

Unsteady simulations of stagnation point flames are conducted in order to study flame turbulence interactions in a relatively simple flow environment. Flame propagation is represented using a flamelet model called the G equation. Two subgrid models are used to close the filtered G equation. The effects of significant heat release on the turbulent flow and the effect of varying turbulence intens...

This paper investigates differentiated design standards as a source of capacity additions that are more affordable and have smaller aesthetic and environmental impacts than modern expressways. We consider several tradeoffs, including narrow versus wide lanes and shoulders on an expressway of a given total width, and high-speed expressway versus lower-speed arterial. We quantify the situations i...

in this study, the effects of linear and rotational speed of the friction stir welding tool was investigated on the heat generation and distribution at surface and inside of workpiece, material flow and geometry of the welding area of poly methyl methacrylate (pmma) workpiece. the commercial cfd fluent 6.4 software was used to simulation of the process with computational fluid dynamic technique...

Extensive two-dimensional Langevin dynamics simulations are used to determine the effect of steady shear flows on the crystal nucleation kinetics of charge stabilized colloids and colloids whose pair potential possess an attractive shallow well of a few k_{B}T 's (attractive colloids). Results show that in both types of systems small amounts of shear speeds up the crystallization process and en...

We have recently reported that the head systematically deviates toward the future direction of the trajectory about 500 ms before attaining a turning point of 90 degrees corner trajectories both in light and in darkness. Here, we investigated how this anticipatory strategy is modified whilst varying visual conditions (Experiment 1) and walking speed (Experiment 2). Exp. 1 showed similar anticip...

We examined the vection in depth induced when simulated random self-accelerations (jitter) and periodic self-accelerations (oscillation) were added to radial expanding optic flow (simulating constant-velocity forward self-motion). Contrary to the predictions of sensory-conflict theory frontal-plane jitter and oscillation were both found to significantly decrease the onsets and increase the spee...