Abstract: Methods to pattern substrates with dense periodic nanostructures that combine top-down lithographic tools and self-assembling block copolymer materials are provided. According to various embodiments, the methods involve chemically patterning a substrate, depositing a block copolymer film on the chemically patterned imaging layer, and allowing the block copolymer to self-assemble in the presence of the chemically patterned substrate, thereby producing a pattern in the block copolymer film that is improved over the substrate pattern in terms feature size, shape, and uniformity, as well as regular spacing between arrays of features and between the features within each array compared to the substrate pattern. In certain embodiments, the density and total number of pattern features in the block copolymer film is also increased. High density and quality nanoimprint templates and other nanopatterned structures are also provided.

Abstract: Multiple objects in a multi-tiered storage system are classified according to multiple metadata fields. Access histories of the classified objects are tracked. Tracked access histories for objects having given values for given metadata fields are amalgamated. Access probability distributions are determined for objects having given values for given metadata fields, based on the amalgamated access histories. Responsive to a new object being added to the system, the new object is classified according to multiple metadata fields. For each specific one of the multiple metadata fields according to which the new object is classified, the determined access probability distribution for objects having the same metadata classification value as the new object is retrieved. The predicted access probability distribution for the new object is determined, by combining the retrieved access probability distributions.

Abstract: A method of manufacturing a disk drive is disclosed. After installing at least one disk into a base, a media cover is coupled to the base, wherein the media cover covers at least a portion of the disk. After coupling the media cover to the base, a head coupled to an actuator arm and a voice coil motor for rotating the actuator arm about a pivot is installed into the base. After installing into the base the head coupled to the actuator arm and the voice coil motor, the media cover is removed from the base. After removing the media cover from the base, a HDA cover is coupled to the base to form a head disk assembly (HDA).