Showing papers on "Crossover published in 1971"

Constant-Voltage Crossover Network Design

Abstract: Consideration of the electroacoustic behavior of common loudspeaker drivers leads to the general crossover network design requirement of constant total voltage transfer. Conventional passive networks satisfy this requirement only if the cutoff slopes are limited to 6 dB per octave. Active crossover networks with steeper cutoff slopes can also be designed to meet this requirement, but these networks do not provide a rapid transition between drivers. Regardless of the network chosen, the drivers used must have useful frequency ranges which overlap by about four octaves.

Fuel burner crossover arrangement

Abstract: An elongated burner body having a series of fuel ports extending along the axis of the burner body is provided with a crossover fuel aperture adjacent the fuel inlet end of the burner. A crossover body comprising a hollow transversely extending member is provided with a crossover fuel inlet aperture from the downstream edge of which extends a depending scoop element. The crossover body is assembled on the burner body so that the crossover fuel apertures are in registration with each other. The scoop serves as a means for locating the crossover body with respect to the burner body and to direct fuel from the burner into the crossover. The scoop element is provided with an opening which allows a portion of the fuel mixture to pass through the opening to directly supply gas to the burner fuel ports most closely adjacent to the crossover and thereby to provide a dependable source of fuel for smooth ignition by the crossover.

Decision-directed decoder for a binary symmetric channel with unknown crossover probability

Abstract: We consider a suboptimum decision-directed block decoder for a binary symmetric channel that makes use of past decoding decisions to update its estimate of the channel's initially unknown crossover probability. The decoder has a threshold list decoding rule that uses the current estimated crossover probability. The estimate is updated by means of a stochastic approximation algorithm. It is shown to converge toward the true crossover probability with a bias that decreases exponentially with the code's block length, provided it never "runs away" toward zero after dropping below a certain critical value. The probability that this runaway phenomenon ever occurs is bounded by an expression that is exponentially decreasing in the code's block length and in the weight assigned to the initial estimate.