Barry M. G. Cheetham

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Delivering electronic goods over the Internet is one of the e-commerce applications that will proliferate in the coming years. Certified e-goods delivery is a process where valuable e-goods are exchanged for an acknowledgement of their reception. This paper proposes an efficient security protocol for certified e-goods delivery with the following features:(More)
Sinusoidal transform coding (STC) techniques model speech as the sum of sine-waves whose frequencies, amplitudes and phases are specified at regular intervals. To achieve a low-bit rate representation, only the spectral envelope is encoded and the phases are regenerated according to a minimum phase assumption. In this paper, the inaccuracy of the minimum(More)
Wheeze is a classic sign of airflow obstruction but relatively little is known of its mechanism of production or its relationship to the development of airflow obstruction. We studied eight asthmatic subjects age (mean +/- 5D) 42 +/- 5 yr, FEV1 2.46 +/- 0.36 L during an extended, symptom-limited methacholine challenge test. Breath sounds were detected by a(More)
Many types of parameters have been proposed for the evaluation of vocal cord abnormalities by speech waveform analysis. However, none of them taken separately allows a reliable assessment of the presence and the degree of abnormality. In this study we proposed to combine three different parameters which take into account different consequences of the(More)
Many low bit-rate speech coders represent the spectral envelope by an all-pole digital filter whose coefficients are calculated by a form of linear prediction (LP) analysis. The lower the bit-rate, the more critical will be the accuracy of the spectral analysis for achieving good quality speech. This paper compares four known techniques: a technique based(More)
The objective measurement of hoarseness by measuring 'jitter' (the average percentage pitch-period variation between consecutive pitch-cycles) using an inverse filtering technique is described. Twenty-five patients with a variety of causes of hoarseness were studied, together with five individuals who had mild hoarseness induced by histamine challenge and(More)