The problem of document replacement in web caches has received much attention in recent research, and it has been shown that the eviction rule “replace the least recently used document” performs poorly in web caches. Instead, it has been shown that using a combination of several criteria, such as the recentness and frequency of use, the size, and the cost of fetching a document, leads to a size...

With an ever increasing amount of data to store, hierarchical storage management (HSM) systems must still use tape for tertiary storage. A disk cache is used to reduce the access time to data stored on tapes in a robot device. Due to the sequential access to tape devices, some HSM systems will transfer whole files between disk cache and tape. In this case the disk cache is forced to handle stor...

In a large-scale information system such as a digital library or the web, a set of distributed caches can improve their eeectiveness by coordinating their data placement decisions. Using simulation, we examine three practical cooperative placement algorithms including one that is provably close to optimal, and we compare these algorithms to the optimal placement algorithm and several cooperativ...

a considerable problem in competitive trade world is choosing the best supply chain. as a result in much more serious circumstances of competitions looking for the best supplier for manufacturing, for preparing raw material, is very significant. meantime suppliers have different scenarios to be fulfilled, such as changing selection variables like lead-time, transportation cost and transportatio...