Computational Auditory Scene Analysis by using statistics of high-dimensional speech dynamics and sound source direction

A main task for computational auditory scene analysis (CASA) is to separate several concurrent speech sources. From psychoacoustics it is known that common onsets, common amplitude modulation and sound source direction are among the important cues which allow the separation for the human auditory system. A new algorithm is presented here, that performs statistical estimation of different sources by a state-space approach which integrates temporal and frequency-specific features of speech. It is based on a Sequential Monte Carlo (SMC) scheme and tracks magnitude spectra and direction on a frame-by-frame basis. First results for estimating sound source direction and separating the envelopes of two voices are shown. The results indicate that the algorithm is able to localize two superimposed sound sources in a time scale of 50 ms. This is achieved by integrating measured high-dimensional statistics of speech. Also, the algorithm is able to track the short-time envelope and the short-time magnitude spectra of both voices on a time scale of 10-40ms. The algorithm presented in this paper is developed for but not restricted to use in binaural hearing aid applications, as it is based on two head-mounted microphone signals as input. It is conceptionally able to separate more than two voices and integrate additional cues. 1

The performance of dual-energy CT in the classification criteria of gout: a prospective study in subjects with unclassified arthritis

OBJECTIVE: To establish the performance of (subsets of) the 2015 ACR/EULAR gout classification criteria in patients with unclassified arthritis, and to determine the value of dual-energy CT (DECT) herein. Reference was the MSU crystal detection result in SF at polarization microscopy. METHODS: We included subjects with acute, unclassified mono or oligoarthritis, who underwent SF analysis and DECT. Performance was assessed by calculating area under the receiver operating characteristic curve of (i) the clinical criteria subset, (ii) the clinical+serum urate subset and (iii) the full set (including DECT). RESULTS: Of the 89 subjects enrolled, 40 met the clinical+serum urate subset criteria, and 49 (55%) subjects did not. Of these 49, 30 had a negative microscopy result, of whom 15 had positive DECT; of these 15, 14 met the full set criteria only after adding the positive DECT result. For the clinical-only subset, the areas under the curves (AUCs) were 0.68 and 0.69 without and with DECT result, respectively, and for the clinical+serum urate subset without and with DECT, AUCs were 0.81 and 0.81, respectively (results not significant). CONCLUSION: Adding the serum urate results to the clinical subset improves the performance, but adding the DECT result does not, neither does adding the DECT results to the clinical+serum urate subset. However, DECT seems to have an additive value in gout classification, especially when microscopy of SF is negative; 14/89 of patients (16%) only met the classification criteria with the use of DECT. TRIAL REGISTRATION: ClinicalTrials.gov, http://clinicaltrials.gov, NCT03038386

Shape Modification of Germanium Nanowires during Ion Irradiation and Subsequent Solid-Phase Epitaxial Growth

During ion irradiation which is often used for the purposes of bandgap engineering, nanostructures can experience a phenomenon known as ion‐induced bending (IIB). The mechanisms behind this permanent deformation are the subject of debate. In this work, germanium nanowires are irradiated with 30 or 70 keV xenon ions to induce bending either away from or toward the ion beam. By comparing experimental results with Monte Carlo calculations, the direction of the bending is found to depend on the damage profile over the cross section of the nanowire. After irradiation, the nanowires are annealed at temperatures up to 440 \ub0C triggering solid‐phase epitaxial growth (SPEG) causing further modification to the deformed nanowires. After IIB, it is observed that nanowires which had bent away from the ion beam then straighten during SPEG while those which had bent toward the ion beam bend even more. This is attributed to differences in the mechanisms responsible for the ion‐beam‐induced bending in opposite directions. Thus, the results reported here give insights into the mechanisms causing the IIB of nanowires and demonstrate how to predict the evolution of nanowires under irradiation and annealing. Finally, they show that, under certain conditions, the bending can even be removed via SPEG