We describe and evaluate an algorithm for determining decision-feedback equalizer (DFE) coefficient placements from an estimated channel response. Efficient tap placement is desirable to minimize equalizer computation in multichannel, underwater acoustic environments due to long, potentially sparse channel responses lasting hundreds of symbols or more. Although our algorithm relies on heuristic...

This paper addresses the problem of finding a subset of the acoustic feature space that best represents the phoneme set used in a speech recognition system. A maximum mutual information approach is presented for selecting acoustic features to be combined together to represent the distinctions among the phonemes. The overall phoneme recognition accuracy is slightly increased for the same length ...

The motivation of our work is to detect different terrain types traversed by a robot based on acoustic data from the robot-terrain interaction. Different acoustic features and classifiers were investigated, such as Mel-frequency cepstral coefficient and Gamma-tone frequency cepstral coefficient for the feature extraction, and Gaussian mixture model and Feed forward neural network for the classi...

Advances in nanotechnology have provided acoustic researchers with a number of new materials with nano-fibres and nano-pores that can potentially be implemented as an acoustic porous absorber. This paper investigates the acoustic absorption behaviour of carbon nanotube (CNT) arrays, in order to quantify the acoustic characteristics and absorption performance of nanoscopic fibres in comparison w...

This paper experimentally investigates the acoustic behavior of a homogeneous porous material with a rigid frame (metallic foam) under grazing flow. The transmission coefficient shows an unusual oscillation over a particular range of frequencies which reports the presence of an unstable hydrodynamic wave that can exchange energy with the acoustic waves. This coupling of acoustic and hydrodynami...

End tidal carbon dioxide measurement with an electro acoustic sensor has recently been demonstrated. The sensor consists of an acoustic resonator coupled to a low cost electro acoustic element. The aim of this study was to verify if ambient temperature variation would affect the measurements. By simultaneous measurements with a reference sensor, the electro acoustic capnograph was tested on sub...

Since the measurement of mechanical sealing film thickness and just-lift-off time is very difficult, the sealing film condition monitoring method based on acoustic emission signal is proposed. The mechanical seal acoustic emission signal present obvious characteristics of time-varying nonlinear and pulsating. In this paper, the acoustic emission signal is used to monitor the seal end faces just...

Unruh [1] demonstrated that black holes have an analogy in acoustics. Under this analogy the acoustic event horizon is defined by the set of points in which the local background flow exceeds the local sound speed. In past work [2], we demonstrated that under a white noise source, the acoustic event horizon will radiate at a thermal spectrum via a classical tunneling process. In this work, I sum...

The present research studied the acoustic properties of 40 oak timber samples (Quercus castaneifolia): the acoustic coefficient (K) and acoustic conversion efficiency (ACE) in free vibration mode, using the free-free bar method with different planes of vibration, i.e., tangential (LT) and radial (LR). These acoustic parameters were considered for both primary virgin wooden beams and modified be...