Abstract: A hardware and software facility for classifying media content units using keywords from a structured vocabulary. Metadata associated with each media content unit is segmented into a series of descriptive phrases. The descriptive phrases are mapped to keywords in a structured vocabulary, and the identified keywords associated with the media content units. Descriptive phrases that are not found in the structured vocabulary are tracked as candidate phrases for later addition to the structured vocabulary. A keyword index to the media content units may be constructed. The index is used to identify specific media content units that are responsive to search queries in a reliable and accurate fashion.

Abstract: Spurious frequencies are suppressed in a transmitter by an RF pulse fall time controller circuit comprising a quadrature hybrid matched attenuator located between a predriver and the first stage of class "C" driver amplifiers. The circuit linearly attenuates RF pulses and slows pulse fall time. Operation of the circuit is initiated when the rising edge of a pretrigger starts a pretrigger generator which then triggers the application of current bias to the attenuator circuit. After a controlled period of time, the circuit decreases the forward current bias of PIN diodes in the attenuator thereby increasing the diodes' series resistance and increasing the attenuation of the RF pulses. This creates a slow pulse fall time thereby suppressing spurious emissions caused by parasitic ringing of the cascaded Class C common base transistor amplifiers in the transmitter.

Abstract: A telescoping door closer or strut is disclosed wherein a sliding rod is automatically held at any desired position of extension or retraction with respect to an associated housing. An automatic brake and hold mechanism for retaining the rod in the desired position includes an annular disk-like brake mounted on the rod and pivotable from a transverse position where the rod slides freely therethrough and an oblique position where the rod is cramped and retained by the brake. One edge or side of the brake is restrained to cause it to pivot into the oblique position upon movement of the rod in a first direction. A stop attached to the housing engages the opposite side of brake to keep it in the transverse position upon movement of the rod in the opposite direction.

Abstract: Spurious frequencies are suppressed in a transmitter by an RF pulse fall time controller circuit comprising a quadrature hybrid matched attenuator located between a predriver and the first stage of class "C" driver amplifiers. The circuit linearly attenuates RF pulses and slows pulse fall time. Operation of the circuit is initiated when the rising edge of a pretrigger starts a pretrigger generator which then triggers the application of current bias to the attenuator circuit. After a controlled period of time, the circuit decreases the forward current bias of PIN diodes in the attenuator thereby increasing the diodes' series resistance and increasing the attenuation of the RF pulses. This creates a slow pulse fall time thereby suppressing spurious emissions caused by parasitic ringing of the cascaded Class C common base transistor amplifiers in the transmitter.