On Conical Roller Expander

On expander codes

Expander codes count among the numerous applications of expander graphs. The term was first coined by Sipser and Spielman when they showed how expander graphs can be used to devise error-correcting codes with large blocklengths that can correct efficiently a constant fraction of errors. This approach has since proved to be a fertile avenue of research that provides insight both into modern iter...

On Expander Codes

Vertex Percolation on Expander Graphs

We say that a graph G = (V,E) on n vertices is a β-expander for some constant β > 0 if every U ⊆ V of cardinality |U | ≤ n 2 satisfies |NG(U)| ≥ β|U | where NG(U) denotes the neighborhood of U . We explore the process of uniformly at random deleting vertices of a β-expander with probability n for some constant α > 0. Our main result implies that as n tends to infinity, the deletion process perf...

Expander Graphs

This paper will introduce expander graphs. Kolmogorov and Barzdin’s proof on the three dimensional realization of networks will be discussed as one of the first examples of expander graphs. The last section will discuss error correcting code as an application of expander graphs to computer science.

The Rolling Resistances of Roller Skis and Their Effects on Human Performance during Treadmill Roller Skiing

Modern ski-treadmills allow cross-country skiers, biathletes and ski-orienteers to test their physical performance in a laboratory environment using classical and freestyle techniques on roller skis. For elite athletes the differences in performance between test occasions are quite small, thus emphasising the importance of knowing the roller skis’ rolling resistance coefficient, μR, in order to...