Abstract: In one aspect, a system is described. The system may include a rotor, a plurality of magnets positioned adjacent to the rotor, and a stator defining a plurality of sections. Each of the plurality of sections of the stator may include a plurality of teeth. The system may also include a plurality of winding wires wound around the plurality of teeth of each of the plurality of sections of the stator. The plurality of winding wires wound around the plurality of teeth may define a plurality of single-phase sub-motors. The plurality of single-phase sub-motors have a magnetic design such that at least one of the plurality of single-phase sub-motors are rotationally offset from an adjacent single-phase sub-motor, which may improve motor performance and voltage isolation. The system may also include a plurality of inverters coupled to the plurality of winding wires.

Abstract: A method may involve winding a stator of a motor having m phases, wherein the stator includes n teeth. The method may include winding a wire around a first tooth of the stator and winding the wire around a second tooth of the stator, wherein the second tooth is ( n 2 ? m - 1 ) teeth from the first tooth. The method may also include winding the wire around a third tooth of the stator, wherein the third tooth is [ ( m - 1 ) * ( n 2 ? m ) ] + 1 teeth from the second tooth. The method may also include winding the wire around a fourth tooth of the stator, wherein the fourth tooth is ( n 2 ? m - 1 ) teeth from the third tooth. The method may also include winding the wire around a fifth tooth of the stator, wherein the fifth tooth is [ ( m - 1 ) * ( n 2 ? m ) ] + 2 teeth from the fourth tooth.

Abstract: A method by which a disk-based distributed data storage system is organized for protecting historical records of stored data entities. The method comprises recording distinct states of an entity, corresponding to different moments of time, as separate entity versions coexisting within the distributed data storage system, and assigning expiration times to the entity versions independently within each of a plurality of storage sites according to a shared set of rules, before which times deletion is prohibited.

Abstract: A method by which a disk-based distributed data storage system is organized for protecting historical records of stored data entities. The method comprises recording distinct states of an entity, corresponding to different moments of time, as separate entity versions coexisting within the distributed data storage system, and assigning expiration times to the entity versions independently within each of a plurality of storage sites according to a shared set of rules, before which times deletion is prohibited.

Abstract: A method by which a disk-based distributed data storage system is organized for protecting historical records of stored data entities. The method comprises recording distinct states of an entity, corresponding to different moments of time, as separate entity versions coexisting within the distributed data storage system, and assigning expiration times to the entity versions independently within each of a plurality of storage sites according to a shared set of rules, before which times deletion is prohibited.

Abstract: A method for keeping track, in an electronic data processing system, of when references made to an element that is stored in memory have all been removed, the method being designed to deal with failures in a manner that does not falsely conclude there are no references.

Abstract: In general, the invention features methods by which more than one client program connected to a network stores the same data item on a storage device of a data repository connected to the network. In one aspect, the method comprises encrypting the data item using a key derived from the content of the data item, determining a digital fingerprint of the data item, and storing the data item on the storage device at a location or locations associated with the digital fingerprint. In a second aspect, the method comprises determining a digital fingerprint of the data item, testing for whether the data item is already stored in the repository by comparing the digital fingerprint of the data item to the digital fingerprints of data items already in storage in the repository, and challenging a client that is attempting to deposit a data item already stored in the repository, to ascertain that the client has the full data item.

Abstract: A method by which a disk-based distributed data storage system is organized for protecting historical records of stored data entities. The method comprises recording distinct states of an entity, corresponding to different moments of time, as separate entity versions coexisting within the distributed data storage system, and assigning expiration times to the entity versions independently within each of a plurality of storage sites according to a shared set of rules, before which times deletion is prohibited.

Abstract: A method for turning variable-length file path names into fixed-length object identifiers in a data repository, the method comprising, assigning a fixed-value identifier to a file system in the data repository, computing a first deterministic pseudo-random function that combines a first component of a plurality of file system pathname components associated with a file with the fixed-value identifier, computing a second deterministic pseudo-random function that combines a second component of the plurality of file system pathname components with the result of the first function, and using at least one of the computed deterministic pseudo-random functions to produce a fixed-length object identifier for the file.

Abstract: In general, the invention features methods by which more than one client program connected to a network stores the same data item on a storage device of a data repository connected to the network. In one aspect, the method comprises encrypting the data item using a key derived from the content of the data item, determining a digital fingerprint of the data item, and storing the data item on the storage device at a location or locations associated with the digital fingerprint. In a second aspect, the method comprises determining a digital fingerprint of the data item, testing for whether the data item is already stored in the repository by comparing the digital fingerprint of the data item to the digital fingerprints of data items already in storage in the repository, and challenging a client that is attempting to deposit a data item already stored in the repository, to ascertain that the client has the full data item.

Abstract: A method by which a disk-based distributed data storage system is organized for protecting historical records of stored data entities. The method comprises recording distinct states of an entity, corresponding to different moments of time, as separate entity versions coexisting within the distributed data storage system, and assigning expiration times to the entity versions independently within each of a plurality of storage sites according to a shared set of rules, before which times deletion is prohibited.

Abstract: In general, the invention features methods by which more than one client program connected to a network stores the same data item on a storage device of a data repository connected to the network. In one aspect, the method comprises encrypting the data item using a key derived from the content of the data item, determining a digital fingerprint of the data item, and storing the data item on the storage device at a location or locations associated with the digital fingerprint. In a second aspect, the method comprises determining a digital fingerprint of the data item, testing for whether the data item is already stored in the repository by comparing the digital fingerprint of the data item to the digital fingerprints of data items already in storage in the repository, and challenging a client that is attempting to deposit a data item already stored in the repository, to ascertain that the client has the full data item.

Abstract: A method for providing naming and access control of data items in a data repository, the method comprising having a first client program deposit a data item in the data repository, the depositing including determining a digital fingerprint from the data item, and storing the data item in the data repository at a location or locations associated with the fingerprint, having the first client program specify an object name for an object that comprises a set of data items, storing in the repository an association between the name and the set of data items, and allowing the client program to retrieve a data item from the set of data items by specifying the object name and without providing the digital fingerprint of any data item or composite of data items.

Abstract: A method by which a disk-based distributed data storage system is organized for protecting historical records of stored data entities. The method comprises recording distinct states of an entity, corresponding to different moments of time, as separate entity versions coexisting within the distributed data storage system, and assigning expiration times to the entity versions independently within each of a plurality of storage sites according to a shared set of rules, before which times deletion is prohibited.