Blind deconvolution of coloured signals based on higher-order cepstra and data fusion

1993 ◽  
Vol 140 (6) ◽  
pp. 356 ◽  
Author(s):  
A.P. Petropulu ◽  
C.L. Nikias
2019 ◽  
Vol 19 (1) ◽  
pp. 202-214 ◽  
Author(s):  
Brennan Dubuc ◽  
Arvin Ebrahimkhanlou ◽  
Salvatore Salamone

This article investigates a guided ultrasonic wave–based data fusion approach for nondestructively monitoring stress redistribution in strands under active corrosion. Within this approach, the stress dependence of velocity (i.e. the acoustoelastic effect) is leveraged for stress measurement, while targeting advantageous frequencies of higher-order modes. To accommodate practical scenarios, where artificial velocity shifts are introduced by sensor reattachment/replacement, a technique called modal modulation is also proposed. To demonstrate the approach, accelerated corrosion testing was carried out on a prestressed strand while measuring higher-order modes in the core wire. The strand was subjected to 29 cycles of accelerated corrosion, with the last cycle resulting in peripheral wire fracture. Data from several higher-order modes yielded multiple estimations of corrosion-induced stress change, which were processed into a single estimate using data fusion and outlier analysis. The data fusion estimate decreased uncertainty (quantified with Gaussian process regression) and showed good agreement with measured values, especially where a large stress increase due to fracture was identified. The results demonstrated that higher-order modes were well suited to data fusion and also confirmed the value of modal modulation.


2019 ◽  
Author(s):  
Evrim Acar ◽  
Carla Schenker ◽  
Yuri Levin-Schwartz ◽  
Vince Calhoun ◽  
Tülay Adalı

ABSTRACTFusing complementary information from different modalities can lead to the discovery of more accurate diagnostic biomarkers for psychiatric disorders. However, biomarker discovery through data fusion is challenging since it requires extracting interpretable and reproducible patterns from data sets, consisting of shared/unshared patterns and of different orders. For example, multi-channel electroencephalography (EEG) signals from multiple subjects can be represented as a third-order tensor with modes:subject,time, andchannel, while functional magnetic resonance imaging (fMRI) data may be in the form ofsubjectbyvoxelmatrices. Traditional data fusion methods rearrange higher-order tensors, such as EEG, as matrices to use matrix factorization-based approaches. In contrast, fusion methods based on coupled matrix and tensor factorizations (CMTF) exploit the potential multi-way structure of higher-order tensors. The CMTF approach has been shown to capture underlying patterns more accurately without imposing strong constraints on the latent neural patterns,i.e., biomarkers. In this paper, EEG, fMRI and structural MRI (sMRI) data collected during an auditory oddball task (AOD) from a group of subjects consisting of patients with schizophrenia and healthy controls, are arranged as matrices and higher-order tensors coupled along thesubjectmode, and jointly analyzed using structure-revealing CMTF methods (also known as advanced CMTF (ACMTF)) focusing on unique identification of underlying patterns in the presence of shared/unshared patterns. We demonstrate that joint analysis of the EEG tensor and fMRI matrix using ACMTF reveals significant and biologically meaningful components in terms of differentiating between patients with schizophrenia and healthy controls while also providing spatial patterns with high resolution and improving the clustering performance compared to the analysis of only the EEG tensor. We also show that these patterns are reproducible, and study reproducibility for different model parameters. In comparison to the joint independent component analysis (jICA) data fusion approach, ACMTF provides easier interpretation of EEG data by revealing a single summary map of the topography for each component. Furthermore, fusion of sMRI data with EEG and fMRI through an ACMTF model provides structural patterns; however, we also show that when fusing data sets from multiple modalities, hence of very different nature, preprocessing plays a crucial role.


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