A Statistical Optimization of Search Time in an Information Retrieval System

摘要

The Magnacard system is used to store large files of inventory information. It consists of a bank of filing cabinet drawers containing oxide coatedcards, each one inch by three inches, which can be read from and written onto by magnetic heads similar to those found in tape recorders. Access to the stored information is provided through a mechanism which can remove a drawer from the bank, read from or write onto the cards in that drawer, and return the drawer to the bank. Consideration is given to the organization of the inventory file within the drawers, in order to optimize the retrieval time for a given number of interrogations a of the file. For a given size f and a given number of interrogations a, in a time period T, there is a value d which will minimize the average time to satisfy the a requests. (Author)