Speaker age estimation for elderly speech recognition in European Portuguese

Phone-like acoustic models (AMs) used in large-vocabulary automatic speech recognition (ASR) systems are usually trained with speech collected from young adult speakers. Using such models, ASR performance may decrease by about 10% absolute when transcribing elderly speech. Ageing is known to alter speech production in ways that require ASR systems to be adapted, in particular at the level of acoustic modeling. In this study, we investigated automatic age estimation in order to select age-specific adapted AMs. A large corpus of read speech from European Portuguese speakers aged 60 or over was used. Age estimation (AE) based on i-vectors and support vector regression achieved mean error rates of about 4.2 and 4.5 years for males and females, respectively. Compared with a baseline ASR system with AMs trained using young adult speech and a WER of 13.9%, the selection of five-year-range adapted AMs, based on the estimated age of the speakers, led to a decrease in WER of about 9.3% relative (1.3% absolute). Comparable gains in ASR performance were observed when considering two larger age ranges (60-75 and 76-90) instead of six five-year ranges, suggesting that it would be sufficient to use the two large ranges only.info:eu-repo/semantics/acceptedVersio

Magnetoencephalography—theory, instrumentation, and applications to noninvasive studies of the working human brain

Magnetoencephalography (MEG) is a noninvasive technique for investigating neuronal activity in the living human brain. The time resolution of the method is better than 1 ms and the spatial discrimination is, under favorable circumstances, 2-3 mm for sources in the cerebral cortex. In MEG studies, the weak 10 fT-1 pT magnetic fields produced by electric currents flowing in neurons are measured with multichannel SQUID (superconducting quantum interference device) gradiometers. The sites in the cerebral cortex that are activated by a stimulus can be found from the detected magnetic-field distribution, provided that appropriate assumptions about the source render the solution of the inverse problem unique. Many interesting properties of the working human brain can be studied, including spontaneous activity and signal processing following external stimuli. For clinical purposes, determination of the locations of epileptic foci is of interest. The authors begin with a general introduction and a short discussion of the neural basis of MEG. The mathematical theory of the method is then explained in detail, followed by a thorough description of MEG instrumentation, data analysis, and practical construction of multi-SQUID devices. Finally, several MEG experiments performed in the authors' laboratory are described, covering studies of evoked responses and of spontaneous activity in both healthy and diseased brains. Many MEG studies by other groups are discussed briefly as well.Peer reviewe

Lukiolaisten ja ammatillista perustutkintoa suorittavien elämäntilanne ja toimeentulo

Tutkimuksessa tarkastellaan toisen asteen opiskelijoiden elämäntilannetta ja toimeentuloa. Ikä ja asumismuoto ovat keskeisimmät heidän toimeentuloonsa vaikuttavat tekijät. Lukiolaisista noin 93 prosenttia ja samanikäisistä ammatillista perustutkintoa suorittavista nuorista noin 70 prosenttia asuu vanhempiensa taloudessa. Yli 20-vuotiaista ammatillista perustutkintoa suorittavista joka viides asuu vanhempiensa kanssa. Lukiolaisista suurin osa (80 prosenttia) kokee pienistä tuloistaan huolimatta taloudellisen asemansa vähintään kohtalaiseksi, mikä heijastelee lähinnä heidän taloudellisesti hyvin epäitsenäistä asemaansa. Huonoksi tai hyvin huonoksi oman taloudellisen asemansa kokee joka viides lukiolainen. Ammatillista tutkintoa suorittavien kokemus omasta taloudellisesta asemasta on huomattavasti negatiivisempi: 45 prosenttia ilmoittaa taloudellisen tilanteensa olevan huono tai hyvin huono. Eroa kokemuksissa eri oppilaitoksissa opiskelevien välillä selittävät ikä, itsenäisempi asuminen ja vanhempien pienemmät tulot. Toisen asteen opiskelijoiden mielestä opintotuki on riittämätön ja järjestelmä epäoikeudenmukainen. Kriittisimpiä ovat opintotukea saaneet. Toisen asteen opintotukeen liittyy olennaisesti kysymys vanhempien, yksilön itsensä ja yhteiskunnan vastuusta opintojen aikaisen toimeentulon rahoittamisessa. Alle 20-vuotiailla, asuivatpa he vanhempiensa taloudessa tai itsenäisesti, opintotukeen vaikuttaa vanhempien tuloja koskeva tiukka tarveharkinta. Lukiolaisista vain 18 prosenttia ja ammatillista perustutkintoa suorittavista noin puolet sai opintorahaa keväällä 2006. Ammatillista tutkintoa suorittavista suurempi osa kuin lukiolaisista on yli 20-vuotiaita ja saa näin ollen opintorahaa. Opintorahan saantiin vaikuttaa heillä myös vanhempien pienemmät tulot sekä yksinhuoltajavanhempien suurempi osuus. 18–19-vuotiaiden opiskelijoiden toimeentulotukiasiakkuudet ovat lisääntyneet merkittävästi 1990-luvun alun jälkeen, minkä taustalla voi olla opintorahan reaaliarvon lasku sekä toisen asteen opintotukeen oikeutettujen osuuden lasku. Heikoimmassa taloudellisessa asemassa ovat itsenäisesti asuvat, etenkin toisella paikkakunnalla opiskelevat nuoret. Itsenäisesti asuvat 16–25-vuotiaat ammatillista perustutkintoa suorittavat ilmoittavat nettokuukausituloikseen 384 euroa kuukaudessa. Itsenäisesti asuvista yli 90 prosenttia ilmoittaa vanhempiensa avustavan säännöllisesti tai satunnaisesti suoraan rahallisesti tai maksamalla asumiskuluja ja laskuja. Kokonaan ilman vanhempien taloudellista tukea on itsenäisesti asuvista alle 20-vuotiaista kahdeksan prosenttia ja noin joka viidennellä tuki on satunnaista. Vuonna 2006 korotettiin vanhempien tulorajoja 15 prosenttia ja vuonna 2007 korotetaan 30 prosenttia. Nykyistä useampi pääsee taas opintorahan piiriin ja osalla tukeen oikeutetuista tuen määrä nousee merkittävästi. Kahden elättäjän lapsiperheissä tulorajojen muutos tuo etuuden saajien joukkoon nuoria verraten läheltä mediaanituloisten ryhmää ja yksinhuoltajien lapsista vain ylimpään tulokymmenykseen kuuluvat lapset tulevat jäämään järjestelmän ulkopuolelle. Tulorajojen indeksijärjestelmä tai säännölliset tulorajojen tarkistukset estäisivät tällaiset vaivihkaa tapahtuvat tuen saatavuuden ja tuen tason laskun.9,00 euro

K -shell diagram and hypersatellite spectra of 4d transition elements

The K-shell diagram (K alpha(1,2) and K beta(1,3)) and hypersatellite (HS) (K-h alpha(1,2)) spectra of Y, Zr, Mo, and Pd have been measured with high energy-resolution using photoexcitation by 90 keV synchrotron radiation. Comparison of the measured and ab initio calculated HS spectra demonstrates the importance of quantum electrodynamical (QED) effects for the HS spectra. Phenomenological fits of the measured spectra by Voigt functions yield accurate values for the shift of the HS from the diagram lines, the splitting of the HS lines, and their intensity ratio. Good agreement with theory was found for all quantities except for the intensity ratio, which is dominated by the intermediacy of the coupling of the angular momenta. The observed deviations imply that our current understanding of the variation of the coupling scheme from LS to jj across the periodic table may require some revision.The K-shell diagram (K alpha(1,2) and K beta(1,3)) and hypersatellite (HS) (K-h alpha(1,2)) spectra of Y, Zr, Mo, and Pd have been measured with high energy-resolution using photoexcitation by 90 keV synchrotron radiation. Comparison of the measured and ab initio calculated HS spectra demonstrates the importance of quantum electrodynamical (QED) effects for the HS spectra. Phenomenological fits of the measured spectra by Voigt functions yield accurate values for the shift of the HS from the diagram lines, the splitting of the HS lines, and their intensity ratio. Good agreement with theory was found for all quantities except for the intensity ratio, which is dominated by the intermediacy of the coupling of the angular momenta. The observed deviations imply that our current understanding of the variation of the coupling scheme from LS to jj across the periodic table may require some revision.The K-shell diagram (K alpha(1,2) and K beta(1,3)) and hypersatellite (HS) (K-h alpha(1,2)) spectra of Y, Zr, Mo, and Pd have been measured with high energy-resolution using photoexcitation by 90 keV synchrotron radiation. Comparison of the measured and ab initio calculated HS spectra demonstrates the importance of quantum electrodynamical (QED) effects for the HS spectra. Phenomenological fits of the measured spectra by Voigt functions yield accurate values for the shift of the HS from the diagram lines, the splitting of the HS lines, and their intensity ratio. Good agreement with theory was found for all quantities except for the intensity ratio, which is dominated by the intermediacy of the coupling of the angular momenta. The observed deviations imply that our current understanding of the variation of the coupling scheme from LS to jj across the periodic table may require some revision.Peer reviewe

Inelastic X-ray scattering in correlated (Mott) insulators

We calculate the inelastic light scattering from X-rays, which allows the photon to transfer both energy and momentum to the strongly correlated charge excitations. We find that the charge transfer peak and the low energy peak both broaden and disperse through the Brillouin zone similar to what is seen in experiments in materials like Ca_2 Cu O_2 Cl_2.Comment: 5 pages Revtex4, 6 figure

Inverse Modeling for MEG/EEG data

We provide an overview of the state-of-the-art for mathematical methods that are used to reconstruct brain activity from neurophysiological data. After a brief introduction on the mathematics of the forward problem, we discuss standard and recently proposed regularization methods, as well as Monte Carlo techniques for Bayesian inference. We classify the inverse methods based on the underlying source model, and discuss advantages and disadvantages. Finally we describe an application to the pre-surgical evaluation of epileptic patients.Comment: 15 pages, 1 figur

High resolution mapping of a novel late blight resistance gene Rpi-avll, from the wild Bolivian species Solanum avilesii

Both Mexico and South America are rich in Solanum species that might be valuable sources of resistance (R) genes to late blight (Phytophthora infestans). Here, we focus on an R gene present in the diploid Bolivian species S. avilesii. The genotype carrying the R gene was resistant to eight out of 10 Phytophthora isolates of various provenances. The identification of a resistant phenotype and the generation of a segregating population allowed the mapping of a single dominant R gene, Rpi-avl1, which is located in an R gene cluster on chromosome 11. This R gene cluster is considered as an R gene “hot spot”, containing R genes to at least five different pathogens. High resolution mapping of the Rpi-avl1 gene revealed a marker co-segregating in 3890 F1 individuals, which may be used for marker assisted selection in breeding programs and for further cloning of Rpi-avl

Quantum Monte Carlo calculation of Compton profiles of solid lithium

Recent high resolution Compton scattering experiments in lithium have shown significant discrepancies with conventional band theoretical results. We present a pseudopotential quantum Monte Carlo study of electron-electron and electron-ion correlation effects on the momentum distribution of lithium. We compute the correlation correction to the valence Compton profiles obtained within Kohn-Sham density functional theory in the local density approximation and determine that electronic correlation does not account for the discrepancy with the experimental results. Our calculations lead do different conclusions than recent GW studies and indicate that other effects (thermal disorder, core-valence separation etc.) must be invoked to explain the discrepancy with experiments.Comment: submitted to Phys. Rev.

A Novel 2D Folding Technique for Enhancing Fermi Surface Signatures in the Momentum Density: Application to Compton Scattering Data from an Al-3at%Li Disordered Alloy

We present a novel technique for enhancing Fermi surface (FS) signatures in the 2D distribution obtained after the 3D momentum density in a crystal is projected along a specific direction in momentum space. These results are useful for investigating fermiology via high resolution Compton scattering and positron annihilation spectroscopies. We focus on the particular case of the (110) projection in an fcc crystal where the standard approach based on the use of the Lock-Crisp-West (LCW) folding theorem fails to give a clear FS image due to the strong overlap with FS images obtained through projection from higher Brillouin zones. We show how these superposed FS images can be disentangled by using a selected set of reciprocal lattice vectors in the folding process. The applicability of our partial folding scheme is illustrated by considering Compton spectra from an Al-3at%Li disordered alloy single crystal. For this purpose, high resolution Compton profiles along nine directions in the (110) plane were measured. Corresponding highly accurate theoretical profiles in Al-3at%Li were computed within the local density approximation (LDA)-based Korringa-Kohn-Rostoker coherent potential approximation (KKR-CPA) first-principles framework. A good level of overall accord between theory and experiment is obtained, some expected discrepancies reflecting electron correlation effects notwithstanding, and the partial folding scheme is shown to yield a clear FS image in the (110) plane in Al-3%Li.Comment: 24 pages, 8 figures, to appear in Phys. Rev.

Multi-sensor system for simultaneous ultra-low-field MRI and MEG

Magnetoencephalography (MEG) and magnetic resonance imaging at ultra-low fields (ULF MRI) are two methods based on the ability of SQUID (superconducting quantum interference device) sensors to detect femtotesla magnetic fields. Combination of these methods will allow simultaneous functional (MEG) and structural (ULF MRI) imaging of the human brain. In this paper, we report the first implementation of a multi-sensor SQUID system designed for both MEG and ULF MRI. We present a multi-channel image of a human hand obtained at 46 microtesla field, as well as results of auditory MEG measurements with the new system.Comment: To appear in Proceedings of 15th International Conference on Biomagnetis