No abstract

The owners of three restaurants requested help with the pay of waitpersons who were paid by the hour. The waitpersons asked for raises which the owners said they could not afford. This research changed the method of compensating waitpersons by making their pay contingent on dollars of food sold. Increased productivity and increased earnings per hour of work for all of the waitpersons followed the beginning of the performance-contingent pay. Most of the waitpersons also earned increased take-home pay when the performance-contingent pay began. There was little improvement in labor costs per dollar of food sold, a measure of benefit to the owners. The fact that benefits to workers occurred without benefits to owners is contrary to common views about the effects of performance-contingent pay.

In software defined radio (SDR), sharp filters of different bandwidth are required to fine tune the desired channel. This requires different computational resources and large number of filter coefficients. This paper proposes a continuously variable bandwidth sharp finite impulse response (FIR) filter with low distortion and low complexity. For this, a fixed length FIR filter is used with two arbitrary sampling rate converters. This system can be used for both the continuous increase as well as decrease of the effective bandwidth of a filter. The low complexity and sharpness are achieved by using the frequency-response masking (FRM) approach for the design of the fixed length FIR filter. The sharp transition width leads to maximum rejection to channel interference in SDR

No abstract

Variable bandwidth filters (VBFs) which are widely used in applications such as SDR channelisers, require online tuning of the frequency characteristics, re-configurability and low complexity. Conventional methods require some mathematical computation to obtain the new filter coefficients for each desired bandwidth. Harris (2009) has proposed a new design method for a variable bandwidth filter without change in the filter coefficient values. But this can be used only for bandwidth reduction. George and Elias (2012) have proposed a design method for bandwidth reduction as well as enhancement. This paper proposes an optimal and totally multiplier-less implementation of a VBF. A frequency response masking filter with continuous coefficients is designed and synthesised in the canonic signed digit (CSD) format. Metaheuristic optimisation algorithms such as differential evolution and harmony search are deployed to determine the optimised filter coefficient values and the system performances in the bandwidth reduction and enhancement cases are evaluated.