IIIF provides researchers rich metadata and media viewing options for comparison of works across cultural heritage collections. Visit the IIIF page to learn more. In the mid-twentieth century, ...

Let X be a complex Banach spcce, and denote by T a strongly continuous semigroup of linear operators denned on X and C by a cosine function of operators with associated sine function S defined on X.

We introduce the cosine-type approximation processes in abstract Banach space setting. The historical roots of these processes go back to W. W. Rogosinski in 1926. The given new definitions use a ...