No abstract

Most speech processing algorithms analyze speech signals frame by frame with a fixed frame rate. Fixed-rate analysis is inconsistent with human speech perception and effectively assigns the same importance or 'weight' to all equiduration frames. In [1], we proposed a variable frame rate (VFR) analysis technique that is based on a Euclidian distance measure. In this paper, we propose another approach for VFR based on the entropy of the signal. We compare entropy and Euclidian distance measures for VFR in ASR experiments using the Aurora2 and TI46 databases. Better performance is observed for the entropy-based VFR over our earlier VFR approach and over the fixed-rate system.

Flexible electronic devices are developing rapidly, especially in medical applications. This paper reports an arrayed flexible piezoelectric micromachined ultrasonic transducer (FPMUT) with a sandwich structure for adjuvant treatment of bone injury. To make the device conformable and stretchable for attaching to the skin surface, the flexible substrate of polydimethylsiloxane (PDMS) was combined with the flexible metal line interconnection between the bulk lead zirconate titanate (PZT) arrays. Simulations and experiments were carried out to verify the resonant frequency and tensile property of the reported FPMUT device. The device had a resonant frequency of 321.15 KHz and a maximum sound pressure level (SPL) of 180.19 dB at the distance of 5 cm in water. In addition, detailed experiments were carried out to test its acoustic performance with different pork tissues, and the results indicated good ultrasound penetration. These findings confirm that the FPMUT shows unique advantages for adjuvant treatment of bone injury.

No abstract