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It is the purpose of the paper to stimulate a systematic investigation of the time-frequency methods used to extract the natural frequency of mechanical structures. In particular, we are interested in cantilever beams, which are simple structures in mechanics, and therefore most appropriate for detailed comparison. We will compare the refined time-frequency spectra for the short-time Fourier transform,...
This paper proposes a new updating technique for adaptive Volterra kernels employed as nonlinear models for the identification of unknown feedback paths in acoustic nonlinear echo cancellation tasks. Considering that nonlinear distortions are mainly introduced for high input levels, the effective step size is shaped according to the instantaneous envelope of the excitation signal. The loudspeaker-enclosure-microphone...
Fingerprints are one the oldest biometrics used in investigations. The fingerprint morphology is considered unique and immutable and it is routinely used to identify an individual from the mark found at the crime scene. The comparison is based solely on the ridges flow and on their discontinuities (i.e. the minutiae), without considering other information possibly embedded in the fingerprint itself...
Most elderly people monitoring systems include the detection of abnormal situations, in particular distress situations, as one of their main goals. In order to reach this objective, many solutions end up combining several modalities such as video tracking, fall detection and sound recognition, so as to increase the reliability of the system. In this work we focus on daily sound recognition as it is...
This paper describes a hands-free speech/sound recognition system developed and evaluated in the framework of the CompanionAble European Project. The system is intended to work continuously on a distant wireless microphone and detect not only vocal commands but also everyday life sounds. The proposed architecture and the description of each module are outlined. In order to have good recognition and...
In this paper, we approach the problem of audio summarization by saliency computation of audio streams, exploring the potential of a modulation model for the detection of perceptually important audio events based on saliency models, along with various fusion schemes for their combination. The fusion schemes include linear, adaptive and nonlinear methods. A machine learning approach, where training...
In this paper, we propose a novel method for the classification of the multi-sensor remote sensing imagery, which represents a vital and fairly unexplored classification problem. The proposed classifier is based on an explicit hierarchical graph-based model sufficiently flexible to deal with multi-source coregistered datasets at each level of the graph. The suggested supervised method relies on a...
In this paper, we consider the speech enhancement problem in a moving car through a blind source separation scheme involving two closely spaced microphones. We propose the use of a new double pseudo affine projection DPAP algorithm to estimate and suppress coherent noise components from speech. The proposed DPAP algorithm is applied to the forward blind source separation FBSS structure and combined...
In this paper, a new procedure for the design of a cascade of IIR Adaptive Notch Filters (ANFs) is presented. The cascade is composed by second-order sections of modified Nehorai Constrained ANFs, with coefficients modeled by a single polynomial of arbitrary order. This approach allows for a design with less parameters to control notch positions than the number of cascaded sections. The resulting...
This paper presents a method to study the distribution of the articulatory information on time-frequency representation calculated from the acoustic speech signal, whose parametrization is achieved using the wavelet packet transform. The main focus is on measuring the relevant acoustic information, in terms of statistical association, for the inference of critical articulator positions. The rank correlation...
In acoustic and network echo cancellation, the detection of doubletalk and echo path channel changes are important to the control of the echo canceller's adaptive filter. This paper investigates joint doubletalk and channel change detection from an M-hypotheses test perspective. Also, using a stationary Gaussian stochastic input signal model, we propose a doubletalk versus channel change detection...
A discrete version of the Ricci flow, applicable to images, is introduced and applied in image denoising and in single-image-based enhancement and super-resolution. This flow is unique among the geometric flows that have been applied in image processing, in that it is the only flow wherein the metric of an image evolves rather than the image itself as is the case in other geometric flows applicable...
A major challenge in designing MAC protocols for wireless sensor networks (WSN) is the uncertainty about the traffic offered by network, which usually forces conservative assumptions leading to a degradation in throughput and delay performance. Traffic estimation is discussed here in the context of the distributed detection WSNs (DD-WSNs). We approach this issue by first showing that the traffic has...
In this paper we propose a new concept of authentication. Beyond deciding whether a user is entitled to the resources he claims, the authentication process provides information about the state of the user and his capacity to responsibly handle the resources he has the right to access. We chose emotions as credentials because aside from being inextricably linked to the user, their variation over time...
Segmentation is an essential and crucial process in 2D-PAGE image analysis. Although several software packages and techniques have been developed and are broadly utilized in biology laboratories, none of them can optimally segment 2D-PAGE images. This paper presents an effective approach for 2D-PAGE image segmentation. This approach extends our previous work by improving the segmentation accuracy...
In this paper the earlier proposed short-time objective intelligibility predictor (STOI) is simplified such that it can be expressed as a weighted ℓ2 norm in the auditory domain. Due to the mathematical properties of a norm, STOI can now be used with the matching pursuit algorithm in the n-of-m channel selection technique as found in several cochlear implant (CI) coding strategies. With this technique...
We investigate the use of facial depth data of a speaking subject, captured by the Kinect device, as an additional speechinformative modality to incorporate to a traditional audiovisual automatic speech recognizer. We present our feature extraction algorithm for both visual and accompanying depth modalities, based on a discrete cosine transform of the mouth region-of-interest data, further transformed...
In this paper a new design method for a class of 2D IIR fantype filters based on spectral transformations is proposed. The design starts from an analog prototype filter with specified parameters and whose transfer function is factorized into biquads. Applying an appropriate frequency transformation to the 1D transfer function, the desired 2D filter is directly obtained in a factorized form as well...
As nowadays Direct Digital Frequency Synthesizers (DDFS) are used in a vast area of applications, the demand for simple and efficient hardware design and implementation methods is a highly important aspect. In this paper a new approach is introduced considering Automatic Nonuniform Piecewise linear function Approximation (ANPA). Automatic function generation is performed that enables quick HDL design...
In this work, a particle swarm optimization (PSO) algorithm is used to cooperatively estimate a monitored parameter by sensor nodes in an ad-hoc wireless sensor network (WSN). In the proposed algorithm, every sensor node of a wireless sensor network is equipped with a modified particle swarm optimization (MPSO) algorithm to estimate a parameter of interest. A diffusion scheme is used to cooperatively...
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