Automatic syllabification using segmental conditional random fields

In this paper we present a statistical approach for the automatic syllabification of phonetic word transcriptions. A syllable bigram language model forms the core of the system. Given the large number of syllables in non-syllabic languages, sparsity is the main issue, especially since the available syllabified corpora tend to be small. Traditional back-off mechanisms only give a partial solution to the sparsity problem. In this work we use a set of features for back-off purposes: on the one hand probabilities such as consonant cluster probabilities, and on the other hand a set of rules based on generic syllabification principles such as legality, sonority and maximal onset. For the combination of these highly correlated features with the baseline bigram feature we employ segmental conditional random fields (SCRFs) as statistical framework. The resulting method is very versatile and can be used for any amount of data of any language. The method was tested on various datasets in English and Dutch with dictionary sizes varying between 1 and 60 thousand words. We obtained a 97.96% word accuracy for supervised syllabification and a 91.22% word accuracy for unsupervised syllabification for English. When including the top-2 generated syllabifications for a small fraction of the words, virtual perfect syllabification is obtained in supervised mode

A crude model to study radio frequency induced density modification close to launchers

The interplay between radio frequency (RF) waves and the density is discussed by adopting the general framework of a 2-time-scale multi-fluid treatment, allowing to separate the dynamics on the RF time scale from that on the time scale on which macroscopic density and flows vary as a result of the presence of electromagnetic and/or electrostatic fields. The focus is on regions close to launchers where charge neutrality is incomplete and waves are commonly evanescent. The fast time scale dynamics influences the slow time scale behavior via quasilinear terms (the Ponderomotive force for the case of the equation of motion). Electrons and ions are treated on the same footing. Also, both fast and slow waves are retained in the wave description. Although this work is meant as a subtopic of a large study-the wave induced "convective cell" physics at hand is of a 2- or 3-dimensional nature while this paper limits itself to a single dimension-a few tentative examples are presented

STAT2 signaling restricts viral dissemination but drives severe pneumonia in SARS-CoV-2 infected hamsters

Emergence of SARS-CoV-2 causing COVID-19 has resulted in hundreds of thousands of deaths. In search for key targets of effective therapeutics, robust animal models mimicking COVID-19 in humans are urgently needed. Here, we show that Syrian hamsters, in contrast to mice, are highly permissive to SARS-CoV-2 and develop bronchopneumonia and strong inflammatory responses in the lungs with neutrophil infiltration and edema, further confirmed as consolidations visualized by micro-CT alike in clinical practice. Moreover, we identify an exuberant innate immune response as key player in pathogenesis, in which STAT2 signaling plays a dual role, driving severe lung injury on the one hand, yet restricting systemic virus dissemination on the other. Our results reveal the importance of STAT2-dependent interferon responses in the pathogenesis and virus control during SARS-CoV-2 infection and may help rationalizing new strategies for the treatment of COVID-19 patients. SARS-CoV-2 infection can result in severe lung inflammation and pathology, but host response remains incompletely understood. Here the authors show in Syrian hamsters that STAT2 signaling restricts systemic virus dissemination but also drives severe lung injury, playing a dual role in SARS-CoV-2 infection

Speech technology for accent identification and determination of origin

Van Compernolle D., ''Speech technology for accent identification and determination of origin'', Language and origin - the role of language in European asylum procedures: linguistic and legal perspectives, pp. 99-109, Karin Zwaan, Maaike Verrips and Pieter Muysken eds., 2010 (Proceedings ESF exploratory workshop on language and origin: the role of language in European asylum procedures, April 21-24, 2010, Wassenaar, The Netherlands).status: publishe

Development of a Computational Auditory Model

This report is a summary of the work which I performed on cochlear modeling within the framework of a 2 year cooperation between ESAT-KULeuven and IPO-Eindhoven. This report gives a detailed overview of the development of a computational auditory model and of the obstacles that one can expect on the road towards it. For the casual reader some of the mathematics in it will be painful, but I thought it necessary to include as much detail as possible so that this work can serve as a good technical reference for further development. This report should be considered as a writeup on work in progress. Nevertheless the chapters on cochlear filterbanks and adaptation have reached a more or less finished form, while on the other hand the chapter on data representation and post processing leaves many questions unanswered. I hope to be able to continue work on this topic and present a more conclusive report at some point in the futur

Adaptive filter structures for enhancing cocktail party speech from multiple microphone recordings

Pour améliorer la qualité de signaux de parole, on propose un filtre adaptative efficace, avec structure Griffiths-Jim. Les différentes sections du filtre sont adaptées indépendentes selon un critère de détection du signal désirée. Les délais sont dérivés à base de computation de corrélations et pour les filtres adaptatives on emploie un algorithme du type LMS. Des expériments avec quatre micros ont étés conduits dans un local avec acoustic réverbérant, dans lesquelles on a obtenu une amélioration de 6 à 10 dB SNR

Speech processing strategies for a multichannel cochlear prosthesis

Van Compernolle D., ''Speech processing strategies for a multichannel cochlear prosthesis'', Ph.D. dissertation and technical report G906-7, Stanford University, July 1985, Stanford, California, USA.status: publishe