Abstract: A fluid pump control system for excavators enables fluid pumps to produce hydraulic flows of a quantity great enough to actuate hydraulic actuators for smooth composite operations. The system includes variable displacement fluid pumps, fluid quantity control mechanisms for controlling the discharge quantity of the respective fluid pumps, fluid quantity control signal lines respectively connected to the fluid quantity control mechanisms, signal pressure control lines for bringing the fluid quantity control signal lines into connection with a fluid tank to drop the fluid quantity control signal pressures within the fluid quantity control signal lines, and a plurality of cutoff valves attached to the signal pressure control lines in tandem and shiftable in concert with the shifting movement of spools of a control valve for increasing the fluid quantity control signal pressures within the signal pressure control lines in proportion to the shifting amounts of the cutoff valves.

Abstract: Provided are an apparatus and method for converting a pitch delay using linear prediction in speech transcoding. A linear interpolating portion linearly interpolates a closed-loop pitch delay decoded by a selected mode vocoder (SMV) speech decoder to make the closed-loop pitch delay fit in a search section for open-loop pitch delays of G.723.1 speech encoder, to obtain a changed closed-loop pitch delay of the SMV decoder. A predicted value calculating portion calculates a predicted pitch delay using linear prediction, based on past closed-loop pitch delays of the G.723.1 speech encoder. A difference calculating portion calculates a difference between the changed closed-loop pitch delay of the SMV speech decoder and the calculated predicted pitch delay. When the calculated difference is less than the predetermined threshold value, a pitch delay determining portion determines the changed closed-loop pitch delay of the SMV speech decoder to be an open-loop pitch delay of the G.723.1 speech encoder.