SETI 2020: The Pause That Refreshes? [Turnstile]

SETI home: Internet Distributed Computing for SETI

A luminescent molecular turnstile.

A molecular turnstile based on a hydroquinone luminescent hinge bearing two divergently oriented pyridyl units behaving as a rotor and equipped with a handle composed of a tridentate coordinating site considered as the stator was synthesized and its structure was studied in the solid state by X-ray diffraction on single crystal. Its dynamic behaviour in solution was investigated by 1- and 2-D N...

Maximum Matching in Turnstile Streams

We consider the unweighted bipartite maximum matching problem in the one-pass turnstile streaming model where the input stream consists of edge insertions and deletions. In the insertion-only model, a one-pass 2-approximation streaming algorithm can be easily obtained with space O(n logn), where n denotes the number of vertices of the input graph. We show that no such result is possible if edge...

A New Proposal for RSVP Refreshes

As a soft-state protocol, RSVP specifies that each RSVP node sends periodic control messages to maintain the state for active RSVP sessions. The protocol overhead due to such periodic messages grows linearly with the number of RSVP sessions. One may reduce the overhead by using a longer refresh period, which unfortunately leads to longer delays in re-synchronizing RSVP state. In this paper we i...

Quantifying SETI

It should come as no surprise to readers of QEX that the scientific Search for Extra-Terrestrial Intelligence (SETI, sometimes called the search for the ultimate DX) was initiated by, and is still largely conducted by, radio amateurs. The world’s hams instinctively understand the nature of electromagnetic communications, as well as the nature of the “free space” (or “aether”) that fills the voi...