Stabilization of Traffic Flow by Speed Limit Adaptation

Instability of traffic flow on high-ways leads to non-linear development of jams with detrimental consequences. In order to avoid them we try to formulate an optimal control law by which the flow could be stabilized. For this purpose we describe the influence of speed limit on the stable regime by a new fundamental law that is formulated based upon experimental data of traffic flow. The corresponding non-linear relation indicates how the speed limit has to be adapted to the traffic density in order to provide conditions for a stable flow

Stabilization of Traffic Flow by Speed Limit Adaptation

Instability of traffic flow on high-ways leads to non-linear development of jams with detrimental consequences. In order to avoid them we try to formulate an optimal control law by which the flow could be stabilized. For this purpose we describe the influence of speed limit on the stable regime by a new fundamental law that is formulated based upon experimental data of traffic flow. The corresponding non-linear relation indicates how the speed limit has to be adapted to the traffic density in order to provide conditions for a stable flow

Electrochromic performances of nonstoichiometric NiO thin films

Electrochromic (EC) performances of Ni3 + containing NiO thin films, called modified NiO thin films, prepared either by pulsed laser deposition or by chemical route are reported. When cycled in lithium based electrolyte, the comparison of the EC behavior of nonstoichiometric NiO thin films points out a larger optical contrast for the films synthesized by chemical route with the absence of an activation period on early electrochemical cycling due in particular to a larger porosity. Herein we demonstrate faster kinetics for modified NiO thin films cycled in lithium ion free electrolyte. Finally, X-ray absorption spectroscopy is used for a preliminary understanding of the mechanism involved in this original EC behavior linked to the film characteristics including their disorder character, the presence of Ni3 + and their porous morphology