66 research outputs found
Towards an artificial laboratory for speech procesing
It is our belief that speech recognition algorithms can best be handled
through the effective an efficient cooperation of multiple knowledge
sources . For the development of various types of such algorithms, also
called hybrid speech algorithms and, more generally, for speech processing,
we need some advanced architectures and speech processing environments
. There is also a need to manipulate speech knowledge, through the
use of abstract data structures, to process data bases, and to help the
modeling, simulation, and evaluation of automatic speech recognizers . To
tackle these problems, we propose the new concept of an artificial laboratory for speech processing . Such a system simulates a real laboratory
and allows analysis of data . It also provides a large range of computing
facilities which can be used with ease to perform modeling and simulation .
In this correspondence, the main concepts of the system are briefly
described.Le travail présenté dans cette correspondance s'appuie sur l'idée que le développement d'algorithmes pour la reconnaissance automatique de la parole nécessite des connaissances variées qui doivent coopérer. Afin d'aider au développement de tels algorithmes, appelés algorithmes hybrides, et de façon plus générale pour le traitement automatique de la parole, des architectures avancées et des environnements intégrés sont souhaitables. Il est aussi souvent nécessaire de représenter les connaissances du domaine parole étudié par l'intermédiaire de structures abstraites, de manipuler des bases de données importantes, et de modéliser, simuler et évaluer des systèmes de reconnaissance automatique de la parol
On the use of an auditory model and phonetic knowledge for automatic speech recognition
Including speech knowledge in automatic speech recognition (ASR)
systems is a good way to improve the performance of recognizers . In this
paper, we propose the ORION system which deals with speaker-independent
ASR for isolated-words . ORION is a two-pass hybrid system which
uses several types of knowledge . This knowledge applies to psychoacoustics,
physiology and phonetics . During the first pass an auditory model,
PLP (perceptually-based linear prediction analysis) combines static and
dynamic features to provide a set of parameters to the dynamic programming
algorithm . After this stage 98 % recognition accuracy was obtained
for a digit vocabulary and 12 templates per word . The introduction of phonetic knowledge in the second pass decreases the error rate by more
Chan 60 % (compared to the results of the first pass) for a confusable
vocabulary (E-SET) .L'introduction de connaissances dans les systèmes de reconnaissance de
parole (RAP) est un bon moyen d'améliorer les performances des
systèmes actuels . Dans cet article nous proposons le système ORION
dans le cadre d'une application de reconnaissance multilocuteur de mots
isolés . ORION est un système hybride à deux passes intégrant plusieurs
sources de connaissances : psychoacoustiques, physiologiques et phonétiques
. Pendant la première passe un modèle d'analyse acoustique
perceptivement fondé (PLP), combinant des caractéristiques instantanées
et des caractéristiques spectrales dynamiques, est utilisé pour fournir des
vecteurs de paramètres à un algorithme de programmation dynamique .
A l'issue de cette première passe plus de 98 % de mots ont été correctement reconnus pour un vocabulaire de chiffres et 12 références
par mot. L'introduction de connaissances phonétiques durant la
deuxième passe diminue l'erreur de reconnaissance de plus de 60 % (par
rapport aux résultats obtenus lors de la première passe) pour un
vocabulaire de mots acoustiquement similaires (E-SET)
A corpus of audio-visual Lombard speech with frontal and profile views
This paper presents a bi-view (front and side) audiovisual Lombard speech corpus, which is freely available for download. It contains 5400 utterances (2700 Lombard and 2700 plain reference utterances), produced by 54 talkers, with each utterance in the dataset following the same sentence format as the audiovisual “Grid” corpus [Cooke, Barker, Cunningham, and Shao (2006). J. Acoust. Soc. Am. 120(5), 2421–2424]. Analysis of this dataset confirms previous research, showing prominent acoustic, phonetic, and articulatory speech modifications in Lombard speech. In addition, gender differences are observed in the size of Lombard effect. Specifically, female talkers exhibit a greater increase in estimated vowel duration and a greater reduction in F2 frequency
Defining freshwater as a natural resource: a framework linking water use to the area of protection natural resources
© 2019, Springer-Verlag GmbH Germany, part of Springer Nature. Purpose: While many examples have shown unsustainable use of freshwater resources, existing LCIA methods for water use do not comprehensively address impacts to natural resources for future generations. This framework aims to (1) define freshwater resource as an item to protect within the Area of Protection (AoP) natural resources, (2) identify relevant impact pathways affecting freshwater resources, and (3) outline methodological choices for impact characterization model development. Methods: Considering the current scope of the AoP natural resources, the complex nature of freshwater resources and its important dimensions to safeguard safe future supply, a definition of freshwater resource is proposed, including water quality aspects. In order to clearly define what is to be protected, the freshwater resource is put in perspective through the lens of the three main safeguard subjects defined by Dewulf et al. (2015). In addition, an extensive literature review identifies a wide range of possible impact pathways to freshwater resources, establishing the link between different inventory elementary flows (water consumption, emissions, and land use) and their potential to cause long-term freshwater depletion or degradation. Results and discussion: Freshwater as a resource has a particular status in LCA resource assessment. First, it exists in the form of three types of resources: flow, fund, or stock. Then, in addition to being a resource for human economic activities (e.g., hydropower), it is above all a non-substitutable support for life that can be affected by both consumption (source function) and pollution (sink function). Therefore, both types of elementary flows (water consumption and emissions) should be linked to a damage indicator for freshwater as a resource. Land use is also identified as a potential stressor to freshwater resources by altering runoff, infiltration, and erosion processes as well as evapotranspiration. It is suggested to use the concept of recovery period to operationalize this framework: when the recovery period lasts longer than a given period of time, impacts are considered to be irreversible and fall into the concern of freshwater resources protection (i.e., affecting future generations), while short-term impacts effect the AoP ecosystem quality and human health directly. It is shown that it is relevant to include this concept in the impact assessment stage in order to discriminate the long-term from the short-term impacts, as some dynamic fate models already do. Conclusions: This framework provides a solid basis for the consistent development of future LCIA methods for freshwater resources, thereby capturing the potential long-term impacts that could warn decision makers about potential safe water supply issues in the future
Recherches biologiques et hystrophysiologiques sur un Solifuge saharien : <i>Othoes saharae panouse</i>
Optimization of microbial transglutaminase production using experimental designs
International audienceIn prokaryotes, transglutaminase (TGase) has been found only in actinomycetes from the genus Streptoverticillium. The role of this TGase, as well as the mechanism regulating the enzyme expression, are still unknown. In order to improve TGase production by Streptoverticillium cinnamoneum CBS 683.68 and simultaneously elucidate the relationship between growth and TGase activity, we decided to study these two responses using different designs of statistical analysis. Among the five factors tested, casein, glycerol, peptones, yeast extract and oligoelements, only oligoelements were found to have no effect either on growth or on TGase production in a complete factorial design. The two factors casein and glycerol were found to have a highly significant effect on both dry weights and TGase activity in a Box-Behnken design used to improve the model. Finally, the TGase activity was increased three times to reach 0.331 ± 0.038 U/ml with optimum concentrations of casein (38.4 g/l) and glycerol (31.2 g/l) calculated with the help of a composite design. In the course of these experiments, the two responses varied in the same way, demonstrating that growth and TGase production were tightly correlated under the conditions described. However, TGase was produced during the stationary phase of growth in optimized medium, indicating that the enzyme production could be induced
Les Araign\ue9es du Grand Erg occidental (Sahara alg\ue9rien)
Volume: 37Start Page: 966End Page: 97
- …