A difference equation is presented to describe traffic flow on a highway. The difference equation model is derived from the optimal velocity models formulated in terms of the differential equations. It is compared with the differential equation models. We investigate phase transitions among the freely moving phase, the coexisting phase in which jams appear, and the uniform congested phase. The ...

The study on deflagration-to-detonation transition (DDT) is very important because this mechanism has relevance to safety issues in industries, where combustible premixed gases are in general use. However, the quantitative prediction of DDT is one of the major unsolved problems in combustion and detonation theory to date. In this paper, the DDT process is studied theoretically and the critical ...

This paper treats the stability of two superposed gravitating streams rotating about the axis transverse to the horizontal magnetic field. The critical wave number for instability is found to be affected by rotation for propagation perpendicular to the axis about which the system rotates. The critical wave number for instability is not affected by rotation when waves propagate along the axis of...

Anomalous velocity and porosity are often indicators of abnormal pore pressure. It is important, therefore, to be able to link velocity to porosity and rock texture in a rational, firstprinciple-based manner. The critical porosity concept allows for building such rock physics models. Critical porosity is the porosity above which the rock can exist only as a suspension. In sandstones the critica...

The response of rails to moving loads has been a topic of interest for over a century. A related issue, the critical velocity of moving loads is an important matter related to track design. Analytically, in undamped environment, downward as well as upward displacements tend to infinity when the load is moving over an infinite rail at the critical velocity. However, the classical formula predict...

In pipeline transportation of slurry, the existing calculation models of critical deposition velocity face the problem of different model forms only suitable for specific conditions. To address this problem, this paper uses improved “shuffled frog leaping algorithm” (SFLA) to optimize the parameters of the computational model in order to calculate critical deposition velocity. This has been fou...

in exploration seismology, migration refers to a multi-channel processing step that attempts to spatially re-position events and improve focusing. before migration, seismic data is usually displayed with traces plotted at the surface location of the receivers and with a vertical time axis. this means that dipping reflections are systematically mispositioned in the lateral coordinate and the ver...

Twist extrusion process is a rather new route to produce highly strained materials. In this process, severe plastic deformation is applied by large shear strains. In current article, required energy for twist extrusion by use of admissible velocity field together with the upper bound technique is predicted. The proposed model is capable of considering the effect of various parameters such as di...