Abstract: Methods of conducting database transactions. One such method comprises receiving data to be written to a database; identifying a set of shard replicas corresponding to the database to which the data is to be written; transmitting, to each of the replicas in the set, a request to write the data thereto; receiving votes back from the replicas in the set, each vote representing whether the respective replica commits to a writing of the data thereto; determining whether to commit to the writing of the data to the database according to whether a majority of the replicas of every shard having replicas in the set has transmitted a vote committing to the writing of the data thereto; and transmitting an outcome of the determining to each of the replicas in the set.

Abstract: A method and apparatus for partitioning a graph database that includes nodes connected to one another is presented. The method entails determining a node type indicating a type of node that is to be used as mapped nodes, and upon receiving a new node, placing the new node in a partition according to one or more property values associated with the new node if it is a mapped node, and placing the new node in a partition according to its connections to other nodes if it is not a mapped node. The apparatus includes modules containing computer-executable instructions to perform the above method.

Abstract: A Q-switch modulator for a high power laser having a randomly polarized output beam and large divergence angle employs a cascaded arrangement of longitudinal mode acousto-optic modulators, each of which has a Raman Nath or near Raman Nath interaction length. The modulators are optically cascaded such that the distance the randomly polarized laser beam travels through the modulators is effectively confined to the sum of the non coherent interaction lengths thereof. Due to the substantial power level of the laser output, there is heating of the bulk material, which usually results in a shift in the Bragg angle. This has minimal if any effect on the shorter interaction length of the Q-switch modulator of the invention. Also, heating of the bulk material is countered by the incorporation of cooling fluid channels in a heat sink support block coupled in thermal communication with the bulk material.

Abstract: A dual solenoid-based linear motion actuator has a single input for supplying both electrical power and positioning signals for a pair of solenoid coils. A binary control signal alternates between first and second voltage levels, one of which is used for powering the dual solenoid actuator and its control electronics, and also for controllably displacing a movable element to a first of a pair of spaced apart positions terminated by electrically conductive stops. The moveable element is electrically coupled to the second voltage level so that contact with either of the stops will apply the second electrical voltage level to control logic circuitry. The actuator's input terminal is coupled to an electrical energy storage circuit, such as a battery and/or capacitor in parallel with the battery, that serves as the power supply for the actuator, extracting and storing power necessary for operating the control circuitry and energizing the solenoid coils.

Abstract: An M×N optical switching system has a plurality of M optical input ports, each of which is directs a respectively associated optical input beam along one of M spaced apart coplanar parallel input optical paths intersecting an optical coupling path. N optical output ports are installed of the input ports at spaced apart locations of the optical coupling path. Each optical output ports receives a respective optical signal along one of N spaced apart coplanar output optical paths that intersect the optical coupling path apart. M+N mirrors are alignable with a normal bisecting a common angle at a respective intersection of the M input optical paths and the N output optical paths with the optical coupling path. A plurality of actuators controllably move selected mirrors into and out of the optical coupling path, so as to cause an optical signal incident at a selected one of the M optical input ports to be coupled to a selected one of the N optical output ports.

Abstract: A dual solenoid-based linear motion actuator has a single input for supplying both electrical power and positioning signals for a pair of solenoid coils. A binary control signal alternates between first and second voltage levels, one of which is used for powering the dual solenoid actuator and its control electronics, and also for controllably displacing a movable element to a first of a pair of spaced apart positions terminated by electrically conductive stops. The moveable element is electrically coupled to the second voltage level so that contact with either of the stops will apply the second electrical voltage level to control logic circuitry. The actuator's input terminal is coupled to an electrical energy storage circuit, such as a battery and/or capacitor in parallel with the battery, that serves as the power supply for the actuator, extracting and storing power necessary for operating the control circuitry and energizing the solenoid coils.

Abstract: A polarization-independent polychromatic light modulator applies one or more pairs of predetermined RF drive frequencies to an acousto-optic transducer of an acousto-optic modulator body upon which a single beam of randomly polarized or unpolarized polychromatic input light is incident. No precursor polarization separation elements are employed. For each optical wavelength to be extracted from the incident beam, two RF drive frequencies are employed. The acoustic waves launched into the acousto-optic medium by the application of the two frequencies of a given RF drive frequency pair produce respective +1 and -1 order output beam components of the selected output wavelength (as well as a zeroth order beam for that wavelength).

Abstract: An M.times.N optical switching system has a plurality of M optical input ports, each of which is directs a respectively associated optical input beam along one of M spaced apart coplanar parallel input optical paths intersecting an optical coupling path. N optical output ports are installed of the input ports at spaced apart locations of the optical coupling path. Each optical output ports receives a respective optical signal along one of N spaced apart coplanar output optical paths that intersect the optical coupling path apart. M+N mirrors are alignable with a normal bisecting a common angle at a respective intersection of the M input optical paths and the N output optical paths with the optical coupling path. A plurality of actuators controllably move selected mirrors into and out of the optical coupling path, so as to cause an optical signal incident at a selected one of the M optical input ports to be coupled to a selected one of the N optical output ports.

Abstract: An M.times.N optical switching system has a plurality of M optical input ports, each of which is directs a respectively associated optical input beam along one of M spaced apart coplanar parallel input optical paths intersecting an optical coupling path. N optical output ports are installed of the input ports at spaced apart locations of the optical coupling path. Each optical output ports receives a respective optical signal along one of N spaced apart coplanar output optical paths that intersect the optical coupling path apart. M+N mirrors are alignable with a normal bisecting a common angle at a respective intersection of the M input optical paths and the N output optical paths with the optical coupling path. A plurality of actuators controllably move selected mirrors into and out of the optical coupling path, so as to cause an optical signal incident at a selected one of the M optical input ports to be coupled to a selected one of the N optical output ports.

Abstract: An apparatus for rapidly varying the spot size of a scanned imaging laser beam comprises a focusing device (e.g. focussing and collimating lens arrangement) and a beam displacement control device (e.g. a rotary actuator scanner mirror or linear actuator). The beam displacement control device is operative to cause relative displacement between the laser beam and a selected one of a plurality of reflector element positions. Respective ones of the plurality of reflector positions are located at respectively different separation distances from the focusing device. As a result, in the course of traveling along an laser beam path, the laser beam is incident upon the focusing device and the reflector element, so as to be directed to a given spatial location along the path, whereby the laser beam has a resultant beam width that is dependent upon the separation distance between the selected reflector element position and the focusing device.

Abstract: A process for the production of an alkali dispersion includes charging a mixing vessel with a solid alkali metal, a liquid which is inert to the alkali metal and a grinding media. The vessel is connected to a vibrating driver which is vibrated until the alkali metal is ground by the media finely enough to form a dispersion in the liquid. Preferably the driver is a resonant driver which is vibrated at the resonant frequency of the driver. Mineral oils or other liquids containing organohalides such as PCBs can be used as a liquid which is treated during the grinding by the organohalide reacting with the alkali metal.