But they had less results about the cover and avoidance properties and semi cover and avoidance properties and the .

Improvement to the coverage radius and forward-link capacity of the conventional cell system;

In terms of the present situation of Chinese railways in combination with the technology of the GSM-R network,we study forward the algorithm of the calculated cell coverage radius in GSM-R.

And compared with traditional honeycomb systems,it will cause more lower interruption rates and increases the coverage radius of the system.

The covering radius of codes over ring F_2+uF_2 for the Lee distance was studied.

The multicovering radii of a code are recent generalizations of the covering radius of a code .

This paper proposes a novel protocol named half overlay multicast routing that integrates IP layer .

A space is shrinking if and only if it is normal and there is a σ closed rifinement for its any increasing open cover.

If for any increasing open cover of a topology space there is a countable sub cover of it and it is countable meta compactness,it has Lindel o ¨f property.

The definitions of pointwise preimage entropies,preimage branch entropy,and preimage relation entropy for nonautonomous discrete dynamical systems given by a sequence of continuous selfmaps of a compact space are given by using open covers.