In this paper we show that uniformly global asymptotic stability for a family of ordinary differential equations is equivalent to uniformly global exponential stability under a suitable nonlinear change of variables. The same is shown for input-to-state stability and input-to-state exponential stability, and for input-to-state exponential stability and a nonlinear H∞ estimate.

We compare the cost of generating electricity with coal and wind in Chile’s Central Interconnected System (SIC). Our estimates include the cost of marginal damages caused by coal plant emissions. On average, we estimate that the levelized cost of coal, including externalities, is $84/MWh. It is efficient to abate emissions of air pollutants (SOx, NOx and PM2.5) but not of CO2. Then the cost wro...

Surveys by the Addiction Research Foundation of Ontario have produced annual estimates on smoking prevalence since 1991. This report describes the three series of telephone surveys from which these data are drawn as well as future plans to monitor tobacco use in Ontario. In addition to provision of updated descriptive results, the methodology and limitations of the data are discussed. Prevalenc...

Most approaches to visual prostheses have focused on the retina, and for good reasons. The earlier that one introduces signals into the visual system, the more one can take advantage of its prodigious computational abilities. For methods that make use of microelectrodes to introduce electrical signals, however, the limited density and volume occupying nature of the electrodes place severe limit...

Using two UV-sensitive visual pigments and the UV-filtering properties of four mycosporine-like amino acids, mantis shrimp create six spectrally distinct UV receptors. This is yet another example of the unique ways in which mantis shrimp have adapted to extract information from their visual world.