We compare and contrast concave and convex lenses by drawing ray diagrams. In this Closer Look segment on Lenses, we compare and contrast concave and convex lenses by drawing ray diagrams and ...

An important function which is neither concave nor convex often arises in production and inventory models. This function is herein called piecewise concave and can be considered to be a generalization ...

Several new classes of discrete stochastic orderings are introduced for comparing discrete random variables that are valued in an arbitrary ordered finite grid of nonnegative points. These order ...