Wideband powerline positioning for indoor localization

Fingerprinting techniques for indoor localization have been widely explored. A particular approach by Patel et al. sug-gested leveraging of the residential powerline as the signal-ing mechanism for a domestic location capability. In this pa-per, we critically examine that initial work, called powerline positioning (PLP). We find the proposed technique lacking in temporal stability, requiring frequent and undesired re-calibration in some environments. We also determine that there is no a priori method to determine a pair of signal-ing frequencies that will reliably work in any space. We propose a wideband approach to PLP (WPLP) that injects up to 44 different frequencies into the powerline. We show that this WPLP approach improves upon overall positioning accuracy, demonstrates greatly improved temporal stability and has the added advantage of working in commercial in-door spaces

Quantification of rhythm problems in disordered speech : a re-evaluation

Disordered speech can present with rhythmic problems, impacting on an individual’s ability to communicate. Effective treatment relies on the availability of sensitive methods to characterise the problem. Rhythm metrics based on segmental durations originally designed for crosslinguistic research have the potential to provide such information. However, these measures may be associated with problems that impact on their clinical usefulness. This paper aims to address the perceptual validity of crosslinguistic metrics as indicators of rhythmic disorder. Speakers with dysarthria and matched healthy participants performed a range of tasks, including syllable and sentence repetition tasks and a spontaneous monologue. A range of rhythm metrics as well as clinical measures were applied. Results showed that none of the metrics could differentiate disordered from healthy speakers, despite clear perceptual differences, suggesting that factors beyond segment duration impacted on rhythm perception. The investigation also highlighted a number of areas where caution needs to be exercised in the application of rhythm metrics to disordered speech. The paper concludes that the underlying speech impairment leading to the perceptual and acoustic characterisation of rhythmic problems needs to be established through detailed analysis of speech characteristics in order to construct effective treatment plans for individuals with speech disorders