Abstract: An echo canceler has an adaptive filter that generates an echo replica signal from a far-end signal. The filter coefficients of the adaptive filter are updated according to a residual error signal, which is obtained by subtracting the echo replica signal from a near-end signal to cancel echo. A background noise estimator estimates the near-end background noise power level from the residual error signal. A step size calculator uses the estimated near-end background noise power in determining the step size of the adaptive updating of the filter coefficients. When the estimated near-end background noise level is high, a small step size is used, which improves echo cancellation under these conditions. When the estimated near-end background noise level is low, a larger step size is used to permit rapid convergence of the filter coefficients.

Abstract: A redundancy gateway system that can avoid short interruption of data communication caused by system switching in gateway units configured in a multiplex manner for a plurality of systems, and that can maintain the communication state prior to the system switching and avoid degradation of communication quality. A duplicate of a received packet is generated, thereby supplying the packet of the same content to a configuration of gateway units. For each packet, a common write pointer corresponding to identification information appended to the packet is generated. Each gateway unit writes the packet to its own jitter buffer in accordance with the common write pointer corresponding to each supplied packet, sequentially reads out the written packet from the jitter buffer, and generates a TDM signal. One of the gateway units is selectively switched and only the TDM signal generated by the one gateway unit is supplied to a TDM network.

Abstract: An echo canceler has an adaptive filter that generates an echo replica signal from a far-end signal. The filter coefficients of the adaptive filter are updated according to a residual error signal, which is obtained by subtracting the echo replica signal from a near-end signal to cancel echo. A background noise estimator estimates the near-end background noise power level from the residual error signal. A step size calculator uses the estimated near-end background noise power in determining the step size of the adaptive updating of the filter coefficients. When the estimated near-end background noise level is high, a small step size is used, which improves echo cancellation under these conditions. When the estimated near-end background noise level is low, a larger step size is used to permit rapid convergence of the filter coefficients.

Abstract: A redundancy gateway system that can avoid, to the maximum extent, short interruption of data communication caused by system switching in gateway units configured in a multiplex manner for a plurality of systems, and that can maintain the communication state prior to the system switching and avoid degradation of communication quality. A duplicate of a received packet is generated, thereby supplying the packet of the same content to a plurality of gateway units. For each packet, a common write pointer corresponding to identification information appended to the packet is generated. Each of the plurality of gateway units writes the packet to its own jitter buffer in accordance with the common write pointer corresponding to each supplied packet, sequentially reads out the written packet from the jitter buffer, and generates a TDM signal. One of the plurality of gateway units is selectively switched and only the TDM signal generated by the one gateway unit is supplied to a TDM network.

Abstract: This invention aims to shorten cycle time by allowing a robot to be operated with speed capability regardless of the shape of moldings. An extrusion molding apparatus has an extrusion molding machine which delivers an extrusion material which becomes a frame-shaped molding through a nozzle fore end, and a robot which holds a workpiece on which the molding is formed and whose working speed is set so as to make travel speed of workpiece rectilinear portions with respect to the nozzle fore end higher than travel speed of workpiece corner portions with respect to the nozzle fore end. Thus, changes in workpiece travel speed with respect to the nozzle fore end are allowed, and robot working speed is not restricted by the shape of moldings.