End-to-end (E2E) automatic speech recognition (ASR) systems directly map acoustics to words using a unified model. Previous works mostly focus on E2E training a single model which integrates acoustic and language model into a whole. Although E2E training benefits from sequence modeling and simplified decoding pipelines, large amount of transcribed acoustic data is usually required, and traditio...

Intelligent fault diagnosis of complex machinery is crucial for industries to reduce the maintenance cost and to improve fault prediction performance. Acoustic signal is an ideal source for diagnosis because of its inherent characteristics in terms of being non-directional and insensitive to structural resonances. However, there are also two main drawbacks of acoustic signal, one of which is th...

INTRODUCTION Surface relief structures at micro and nanoscales are currently focused in different engineering areas. These structures enable special optical, mechanical or chemical properties of the workpiece surfaces. One example is the riblet surface, on which microgrooves are distributed in flow direction. Compared to smooth surfaces ideal riblet structures have been proven to reduce skin fr...

Underwater acoustic networks in a rapidly growing area of research as it finds different applications for monitoring and collecting data for environmental studies and military surveillance. The need for creating a new set of protocols optimized acoustic communication arises from the major differences in the underwater acoustic communication and terrestrial radio communication. Energy efficiency...

Wireless distributed systems as used in sensor networks, Internet-of-Things and cyber-physical systems, impose high requirements on resource efficiency. Advanced preprocessing and classification of data at the network edge can help to decrease the communication demand and to reduce the amount of data to be processed centrally. In the area of distributed acoustic sensing, the combination of algo...

Faculty of Mathematical and Physical Sciences Department of Mathematics Doctor of Philosophy Numerical computation of resonances and pseudospectra in acoustic scattering by Jacopo Lanzoni Acoustic scattering is a well-known physical phenomenon which arises in a wide range of fields: when acoustic waves propagating in a medium impinge on a localised non-uniformity, such as a density fluctuation ...

Parallel connection of inverter modules is a solution to increase reliability, efficiency and redundancy of inverters in Micro-Grid system. Proper load sharing among parallel inverters is a key point. The circulating current among the inverters can greatly reduce the efficiency or even cause instability of the system. In this paper, a control strategy for improving the load sharing performance ...