Abstract: A projectile and stabilizer therefor are provided. The sliding stabilizer is used instead of fixed or glued tail feathers, vanes or other fletching as a means for stabilizing projectile flight. The invention improves current projectile technology with reduced assembly labor cost, the elimination of bow clearance issues, improved accuracy with the consistent production of the sliding stabilizer, easy replacement of the stabilizer in the field, and improved projectile storage. A sliding stabilizer is designed to slide along the shaft of a projectile and comprises a circumferentially extending wing and a plurality of fins. In use, the stabilizer is positioned at the front of the projectile prior to launch, and the projectile slides quickly through the stabilizer until secured at a stop position at or near the trailing end of the projectile. An annular arrow fletch and arrow stabilizer are also provided.

Abstract: A protocol for implementing ACID transactions that provides snapshot isolation in a distributed setting that does not require synchronized clocks is described. The protocol ensures at commit time that transactions touching common objects do not commit out of order. The protocol can be used in the context of a distributed data lake built on an object store in which clients can transactionally add or remove objects from logical tables.

Abstract: A projectile and stabilizer therefor are provided. The sliding stabilizer is used instead of fixed or glued tail feathers, vanes or other fletching as a means for stabilizing projectile flight. The invention improves current projectile technology with reduced assembly labor cost, the elimination of bow clearance issues, improved accuracy with the consistent production of the sliding stabilizer, easy replacement of the stabilizer in the field, and improved projectile storage. A sliding stabilizer is designed to slide along the shaft of a projectile and comprises a circumferentially extending wing and a plurality of fins. In use, the stabilizer is positioned at the front of the projectile prior to launch, and the projectile slides quickly through the stabilizer until secured at a stop position at or near the trailing end of the projectile. An annular arrow fletch and arrow stabilizer are also provided.

Abstract: A locking system that has an opening in a door adapted and arranged for receiving a lock bolt and a lock fixed in a wall for actuating a lock bolt adapting and arranged for being received by the opening in the door when the door is closed. Alternatively, the locking system is mounted on the exterior of the detention cell door and the adjacent exterior cell wall. The locking system further comprises a blocking strip protruding from a door jamb, the strip coupled to the door jamb, the strip coupled to the door jamb and positioned adjacent the lock bolt for blocking access to the lock bolt between the door and the doorjamb. The locking system further comprises a system for monitoring and reporting the status of a detention cell door, the lock bolt, and the roller bolt.

Abstract: Techniques for using tree data structures to maintain a transactionally consistent set with support for time-travel queries are described. When a transaction commits, a new version of the tree data structure is created using a copy-on-write based method such that the tree shares internal nodes with previous trees to save space. This approach may be used in the implementation of a transactional data catalog in which the files that make up a table are stored in a transactional set.

Abstract: Techniques for implementing systems using transactional version sets are described. Transactional version sets or t-sets include a collection of elements, each having a collection of metadata. A t-set is transactional in that a sequence of updates to one or more t-sets are made within an atomic transaction. A t-set is versioned since each committed transaction that updates it produces a new timestamped version that can be accessed via time-travel queries.

Abstract: A distributed database system maintains data for a logical table by storing, on a plurality of storage nodes, a collection of key-item pairs. An operation to delete a range of these items is processed by first storing, on each of the plurality of storage nodes, a tombstone record indicative of the items to be deleted. The tombstones are committed once each of the plurality of nodes has stored the tombstone. Items within the range are treated as deleted. A cleanup operation deletes items within the range and updates the tombstone.

Abstract: Transaction requests may be ordered in a distributed database according to an independently assigned sequence. Different distributed system nodes, such as a transaction coordinator and a storage node may independently assign sequence numbers to requests to access a distributed database. A storage node may receive the request from a transaction coordinator with an assigned sequence number and another request to which the storage node may assign a sequence number. The storage node can then order performance of the requests based on the sequence numbers.

Abstract: A heated chuck for an ion implantation system selectively clamps a workpiece to a carrier plate having heaters to selectively heat a clamping surface. A gap between a base plate and carrier plate of the heated chuck contains a heat transfer media. A cooling fluid source is coupled to cooling channels in the base plate. A controller operates the heated chuck in a first mode and second mode. In the first mode, the controller does not activate the heaters and flows the cooling fluid through the cooling channel, where heat is transferred through the heat transfer media and to the cooling fluid. In the second mode, the controller activates the heaters and optionally purges the cooling fluid from the cooling channel or otherwise alters its cooling capacity. A gas can be selectively provided in the gap to further control heat transfer in the first and second modes.

Abstract: A projectile and stabilizer therefor are provided. The sliding stabilizer is used instead of fixed or glued tail feathers, vanes or other fletching as a means for stabilizing projectile flight. The invention improves current projectile technology with reduced assembly labor cost, the elimination of bow clearance issues, improved accuracy with the consistent production of the sliding stabilizer, easy replacement of the stabilizer in the field, and improved projectile storage. A sliding stabilizer is designed to slide along the shaft of a projectile and comprises a circumferentially extending wing and a plurality of fins. In use, the stabilizer is positioned at the front of the projectile prior to launch, and the projectile slides quickly through the stabilizer until secured at a stop position at or near the trailing end of the projectile. An annular arrow fletch and arrow stabilizer are also provided.

Abstract: Transaction requests may be ordered in a distributed database according to an independently assigned sequence. Different distributed system nodes, such as a transaction coordinator and a storage node may independently assign sequence numbers to requests to access a distributed database. A storage node may receive the request from a transaction coordinator with an assigned sequence number and another request to which the storage node may assign a sequence number. The storage node can then order performance of the requests based on the sequence numbers.

Abstract: A data delivery service of a service provider may receive respective job specifications for different data transfer jobs between computing infrastructure collections (e.g., data centers). A job specification for a data transfer job may include an amount of data to be transferred for the data transfer job, one or more destinations of data transfers for the data transfer job, and/or one or more flexibility parameters for successful transfer of the data for the data transfer job (e.g., a deadline to transfer the data, available data delivery techniques). The data delivery service may determine a schedule for performing different data transfer jobs between two or more infrastructures based on an analysis of the amount of data to be transferred for each job, the destinations of the data transfer for each job, the flexibility parameters for each job (e.g., included in the respective job specifications), and the connectivity between computing infrastructure collections.

Abstract: A geographically distributed system using a hybrid, multi-master design is disclosed. The system may use global tables, for which both reads and writes may be performed locally, but with a single region serving as a master region. All strongly consistent reads and writes may be sent to the master region, whereas eventually consistent reads and writes may be performed in any region with a replica. The master region may not be statically assigned but may move from region to region. The master region may be assigned manually by client preference or may be assigned and updated automatically based on the time of day or workload characteristics.

Abstract: A locking system that has an opening in a door adapted and arranged for receiving a lock bolt and a lock fixed in a wall for actuating a lock bolt adapting and arranged for being received by the opening in the door when the door is closed. Alternatively, the locking system is mounted on the exterior of the detention cell door and the adjacent exterior cell wall. The locking system further comprises a blocking strip protruding from a door jamb, the strip coupled to the door jamb, the strip coupled to the door jamb and positioned adjacent the lock bolt for blocking access to the lock bolt between the door and the doorjamb. The locking system further comprises a system for monitoring and reporting the status of a detention cell door, the lock bolt, and the roller bolt.

Abstract: Updates performed as part of transaction requests to a data store may be included in a stream of updates. Updates to items in the data store that are included in transactions determined not to be committed to the data store may be excluded from the stream of updates. Records in the stream of updates may include an identifier for the transaction that included the update described by the record. The identifier for the transaction may be used to identify updates to other items in the data store that are included in the same transaction.

Abstract: A workpiece alignment system is provided has a light emission apparatus that directs a light beam at a plurality of wavelengths along a path at a shallow angle toward a first side of a workpiece plane at a peripheral region. A light receiver apparatus, receives the light beam on a second side opposite the first side. A rotation device selectively rotates a workpiece support. According controller determines a position of the workpiece based on an amount of the light beam received through the workpiece when the workpiece intersects the path. A sensitivity of the light receiver apparatus is controlled based on a transmissivity of the workpiece. A position of the workpiece is determined when the workpiece is rotated based on the rotational position, an amount of the light beam received, the transmissivity of the workpiece, detection of a workpiece edge, and the controlled sensitivity of the light receiver apparatus.

Abstract: Disclosed are systems and methods for generating consistent backups. A central coordinator informs each node storing a partition of the time to perform a backup. At the designated time, each node blocks updates for a corresponding time interval measured by its local clock. Each node performs the backup operation according to its own local clock. Consistent backups may be generated in spite of clock skew between the local clocks as long as the time interval is at least as long as a maximum local clock skew (among the nodes performing the backup). In some systems the maximum local clock skew may be reduced, by a round-trip update latency from a client, for example.

Abstract: Transaction requests may be ordered in a distributed database according to an independently assigned sequence. Different distributed system nodes, such as a transaction coordinator and a storage node may independently assign sequence numbers to requests to access a distributed database. A storage node may receive the request from a transaction coordinator with an assigned sequence number and another request to which the storage node may assign a sequence number. The storage node can then order performance of the requests based on the sequence numbers.

Abstract: A locking system that has an opening in a door adapted and arranged for receiving a lock bolt and a lock fixed in a wall for actuating a lock bolt adapting and arranged for being received by the opening in the door when the door is closed. Alternatively, the locking system is mounted on the exterior of the detention cell door and the adjacent exterior cell wall. The locking system further comprises a blocking strip protruding from a door jamb, the strip coupled to the door jamb, the strip coupled to the door jamb and positioned adjacent the lock bolt for blocking access to the lock bolt between the door and the door jamb. The locking system further comprises a system for monitoring and reporting the status of a detention cell door, the lock bolt, and the roller bolt.

Abstract: A geographically distributed system using a hybrid, multi-master design is disclosed. The system may use global tables, for which both reads and writes may be performed locally, but with a single region serving as a master region. All strongly consistent reads and writes may be sent to the master region, whereas eventually consistent reads and writes may be performed in any region with a replica. The master region may not be statically assigned but may move from region to region. The master region may be assigned manually by client preference or may be assigned and updated automatically based on the time of day or workload characteristics.