Several mechanisms may heat the solar chromosphere: acoustic waves, magnetoacoustic waves (slow, fast, and Alfvén waves), and small-scale magnetic reconnections. Based on observations in the Ca II 854.2 nm line, the contribution of acoustic waves to the heating of quiet and plage regions in the chromosphere is discussed. The energy released by radiative losses is compared with the energy deposi...

We consider the problem of learning a linear transformation of acoustic feature vectors for phonetic frame classification, in a setting where articulatory measurements are available at training time. We use the acoustic and articulatory data together in a multi-view learning approach, in particular using canonical correlation analysis to learn linear transformations of the acoustic features tha...

How natural communication sounds are spatially represented across the inferior colliculus, the main center of convergence for auditory information in the midbrain, is not known. The neural representation of the acoustic stimuli results from the interplay of locally differing input and the organization of spectral and temporal neural preferences that change gradually across the nucleus. This rai...

Comparison of brain imaging data requires the exact matching of data sets from different individuals. Warping methods, used to optimize matching of data sets, can exploit either local gray value distribution or identifiable reference points within the images to be compared. Gray value-based warping, which is more comfortable, cannot be used if gray values include functional information that sho...

An efficient finite volume approach has been used to develop a three dimensional Helmholtz acoustic solver for complex geometries. This acoustic solver was utilized to obtain characteristic mode shapes and frequencies of a baffled combustion chamber. An experimental setup, including stationary and moving sensors, has also been used to measure these quantities for the same model combustion chamb...

The stress on a test specimen during tensile testing is generally measured by a strain gauge. This method has some problems in that it would influence the measurement conditions of the tensile test and can evaluate only the position at which the strain gauge is attached. The acoustoelastic method is proposed as a method replacing the strain gauge method. However, an ultrasonic sensor with a pie...

Phase aberration due to tissues with inhomogeneous acoustic speeds is a major source for image degradation in medical ultrasound. In most phased array pulse-echo ultrasound systems, the delay used to steer and focus the beams are calculated assuming constant speed. In practice, however, the acoustic speed varies for different types of tissue. In this paper, we present a method to estimate the p...

Doppler scale estimation is one critical step needed by the resampling operation in acoustic communication receivers. In this paper, we compare different Doppler scale estimation methods using either cyclic-prefixed (CP) or zero-padded (ZP) orthogonal-frequency division-multiplexing (OFDM) waveforms. For a CP-OFDM preamble, a self-correlation method allows for blind Doppler scale estimation bas...

To locate an acoustic source in a room, the relative delay between microphone pairs must be determined efficiently and accurately. However, most traditional time delay estimation (TDE) algorithms fail in reverberant environments. In this paper, a new approach is proposed that takes into account the reverberation of the room. A realtime PC-based TDE system running under Microsoft Windows system ...