Calculation of distribution function of ringing power in telephoneexchange

An exact calculation of the minimum required power of a ringing signal generator in a telephone exchange is presented. The problem of power calculation is treated as a traffic problem. As can be seen, the required ringing power is a function of the traffic parameters of subscribers, the electrical characteristics of the telephone lines and sets, and the allowed overload time     

Wrapping Effect and Wrapping Function

We study the wrapping effect associated with validated interval methods for numerical solution of the initial value problem for ordinary differential equations by introducing a new concept of wrapping function. The wrapping function is proved to be the limit of the enclosures of the solution produced by methods of certain type. There is no wrapping effect if and only if the wrapping function equals the optimal interval enclosure of the solution.