This year marks a significant change in the recent history of hard disk drive development. During the final years of the last century and for the last two years the areal density of magnetic recording had been increasing at rates close to or exceeding 100% per year. That meant that each generation of hard disk drive had a digital data capacity that was close to twice that of the previous genera...

Uncertainty enters into human reasoning and inference in at least two ways. It is reasonable to suppose that there will be roles for these distinct uses of uncertainty also in automated reasoning.

In this note we show how to construct two distinct bipartite graphs which are cospectral for both the adjacency and normalized Laplacian matrices by “unfolding” a base bipartite graph in two different ways.