A corpus contains information including text from books and metadata about the books. The tile includes at least one locating rod embedded within said tile and an internal mechanism for laterally extending said at least one locating rod out of said tile and into a gap in an adjoining structure which may be another tile. The source router receives a reply from the destination router that is transmitted in response to receiving the Ethernet connectivity check request frame and determines a round trip time between the source router and the destination router based on a time of receipt of the reply and the transmission timestamp. Accordingly, carriers generated near the rear surface of the semiconductor substrate are reliably captured by the second depleted layers. After the warm-up period of the current wake up period, a current state value is provided from a state controller to the communication subsystem for use in operating the communication subsystem during the wake up period. Clickstream data generated from the seed URL and additional URLs are analyzed to determine whether the additional URLs belong to the category.