DNSSEC protocol deployment has taken place in phases, beginning with protocol development and followed by the signing of top-level zones and early-adopter “leaf” zones. The next phase is to encourage wide-scale validation, as that will improve the overall DNS system and enable new applications. In order to quantify DNSSEC usage for audiences it is important to be able to measure how many zones ...

A theoretical investigation is made of the effect of finite pulse length on the multipactor breakdown condition for microwave signals. The analysis considers the case of multipactor between two parallel metallic plates, using the classical resonance theory. It is found that decreasing pulse length tends to successively eliminate higher order resonance zones and lead to a ”pulse hardening” of lo...

We consider a dynamical system that exhibits transition chains of invariant tori alternating with Birkhoff zones of instability in a 2-dimensional center manifold. It is known that there exist orbits that shadow the transition chains. It is also known that there exist orbits that cross the Birkhoff zones of instability. We describe a topological mechanism that allows one to join together the tw...