Abstract: A safety system is provided that provides a progressive series of notifications to wirelessly tethered devices based on distance and/or elapsed time criteria when one of the devices physically moves outside of comfort zone set by the other device.

Abstract: A method for replacing disk memory blocks in a cache when a cache miss occurs. A weighting factor is accumulated for each disk memory block which is representative of the number of hits the disk memory block receives. To improve access time, the cache is divided into three buffer segments. The information resides in these buffers based on frequency of access. Upon a cache miss, new data is inserted at the top position of the first buffer, extra data from the bottom of the first buffer is migrated to the top position of the second buffer and extra data from the bottom position of the second buffer is migrated to the top position of the third buffer. The extra data in the third buffer is evicted based on both recentness and frequency of usage. For a cache hit, the weighting factor is augmented and the disk memory block is moved to the top position of the first buffer.