In this paper, congestion dynamics along crowded freeway corridors are modeled as a conservation law with a source term that is continuous in space. The source term represents the net inflow from ramps, postulated here as a location-dependent function of the demand for entering and exiting the corridor. Demands are assumed time-independent, which is appropriate for understanding the onset of co...

We present results on the modeling of onand off-ramps in cellular automata for traffic flow, especially the Nagel-Schreckenberg model. We study two different types of onramps that cause qualitatively the same effects. In a certain density regime ρlow < ρ < ρhigh one observes plateau formation in the fundamental diagram. The plateau value depends on the input-rate of cars at the on-ramp. The on-...

Stimulation of Escherichia coli by exponential ramps of chemoattractants generates step changes in the concentration of the response regulator, CheY-P. Because flagellar motors are ultrasensitive, this should change the fraction of time that motors spin clockwise, the CWbias. However, early work failed to show changes in CWbias when ramps were shallow. This was explained by a model for motor re...

In this paper, congestion dynamics along crowded freeway corridors are modeled as a conservation law with a source term that is continuous in space. The source term represents the net inflow from ramps, postulated here as a location-dependent function of the demand for entering and exiting the corridor. Demands are assumed time-independent, which is appropriate for understanding the onset of co...

We have previously demonstrated a significant inverse correlation between circulating thrombopoietin (TPO) levels and peripheral platelet (PLT) counts in patients with thrombocytopenia secondary to megakaryocytic hypoplasia but not in patients with immune thrombocytopenic purpura (ITP; Chang et al, Blood 88:3354, 1996). To test the hypothesis that the differences in the circulating TPO levels i...

PURPOSE Detecting and recognizing steps and ramps is an important component of the visual accessibility of public spaces for people with impaired vision. The present study, which is part of a larger program of research on visual accessibility, investigated the impact of two factors that may facilitate the recognition of steps and ramps during low-acuity viewing. Visual texture on the ground pla...

We have previously demonstrated a significant inverse correlation between circulating thrombopoietin (TPO) levels and peripheral platelet (PLT) counts in patients with thrombocytopenia secondary to megakaryocytic hypoplasia but not in patients with immune thrombocytopenic purpura (ITP; Chang et al, Blood 88:3354, 1996). To test the hypothesis that the differences in the circulating TPO levels i...

Simplified theory of kinematic waves was proposed by Newell and uses cumulative arrival and departure counts to describe kinematic waves of freeway traffic. The original paper deals only with traffic on freeway mainline. It is of great interest, at least practically, to investigate whether the simplified theory can be used to simulate freeway traffic merging and diverging behavior. In his paper...