3,014 research outputs found
Study of annoyance due to urban automobile traffic
Continuous traffic noise measurements were carried out over 48 hour periods in front of a hundred buildings in different types of streets in Paris and its suburbs. Physical interpretation of the results provides a noise prediction formula for a traditional type of street. The noise at each point was characterized by a limited number of parameters by means of factor analysis, and their effect on the degree of disturbance by 700 individuals questioned near the measurement stations was studied. It was found that many additional factors affect disturbance besides noise, and that the dispersion of replies for any given noise situation is very wide. A disturbance index is proposed which takes into account the daylight level L(50), the position of rooms in the dwelling exposed to noise, and the individual degrees of satisfaction with the area
Sparse and Non-Negative BSS for Noisy Data
Non-negative blind source separation (BSS) has raised interest in various
fields of research, as testified by the wide literature on the topic of
non-negative matrix factorization (NMF). In this context, it is fundamental
that the sources to be estimated present some diversity in order to be
efficiently retrieved. Sparsity is known to enhance such contrast between the
sources while producing very robust approaches, especially to noise. In this
paper we introduce a new algorithm in order to tackle the blind separation of
non-negative sparse sources from noisy measurements. We first show that
sparsity and non-negativity constraints have to be carefully applied on the
sought-after solution. In fact, improperly constrained solutions are unlikely
to be stable and are therefore sub-optimal. The proposed algorithm, named nGMCA
(non-negative Generalized Morphological Component Analysis), makes use of
proximal calculus techniques to provide properly constrained solutions. The
performance of nGMCA compared to other state-of-the-art algorithms is
demonstrated by numerical experiments encompassing a wide variety of settings,
with negligible parameter tuning. In particular, nGMCA is shown to provide
robustness to noise and performs well on synthetic mixtures of real NMR
spectra.Comment: 13 pages, 18 figures, to be published in IEEE Transactions on Signal
Processin
Manifestations électrocardiographiques de l'hyperkaliémie modérée à sévère
L'hyperpotassémie est un désordre électrolytique, qui dans des situations extrêmes, peut conduire au décès. Les premières études effectuées montraient un lien entre la progression du taux de potassium et l'apparition de modifications électrocardiographiques. Certaines études, plus récentes, ont mis en doute cette hypothèse. Notre étude a pour but de chercher quels sont les facteurs associés à l'apparition d'un pattern électrocardiographique typique, en cas d'hyperpotassémie modérée à sévère (≥7mmol/l), dans une population adulte hospitalière, non sélectionnée. Le 2ème objectif est d'estimer la mortalité liée à ce degré d'hyperkaliémie. Etude au design rétrospectif, sélectionnant les patients adultes avec K : ≥ 7mmol/L, entre 2009 et 2010 au CHUV, ayant un électrocardiogramme à disposition entre -1h et +2h de la prise de sang. Recueil des valeurs de laboratoires et des comorbidités de ces patients et analyse des électrocardiogrammes : fréquence cardiaque, durée QRS, durée QTc, amplitudes ondes T et RS, présence d'un trouble de la conduction, d'une fibrillation ou d'un flutter, d'un rythme jonctionnel.
Résultats : Sur les 82 patients sélectionnés, l'analyse statistique a mis en évidence que le taux de potassium n'est corrélé ni à l'apparition de modifications électrocardiographiques typiques, ni à la mortalité. Le seul élément pouvant prédire, sur l'électrocardiogramme, l'apparition d'un pattern typique est le degré d'acidémie. Le risque de décès ou de présenter un arrêt cardiorespiratoire en cas d'hyperkaliémie modérée à sévère est principalement déterminé par la présence d'une acidose métabolique
Study of annoyance due to urban automobile traffic. Annex 5: Sociological study
The aim, method, description, and results of the study of the influence of traffic noise on the annoyance of persons living near points of measurement are discussed. A facsimile of the questionnaire used in the study is included. The essential themes were: the different dimensions of annoyance; the means of defense against noise; the criteria subjects use to describe the noise; attitudes regarding noise; and the functions of noises
Sparsity and adaptivity for the blind separation of partially correlated sources
Blind source separation (BSS) is a very popular technique to analyze
multichannel data. In this context, the data are modeled as the linear
combination of sources to be retrieved. For that purpose, standard BSS methods
all rely on some discrimination principle, whether it is statistical
independence or morphological diversity, to distinguish between the sources.
However, dealing with real-world data reveals that such assumptions are rarely
valid in practice: the signals of interest are more likely partially
correlated, which generally hampers the performances of standard BSS methods.
In this article, we introduce a novel sparsity-enforcing BSS method coined
Adaptive Morphological Component Analysis (AMCA), which is designed to retrieve
sparse and partially correlated sources. More precisely, it makes profit of an
adaptive re-weighting scheme to favor/penalize samples based on their level of
correlation. Extensive numerical experiments have been carried out which show
that the proposed method is robust to the partial correlation of sources while
standard BSS techniques fail. The AMCA algorithm is evaluated in the field of
astrophysics for the separation of physical components from microwave data.Comment: submitted to IEEE Transactions on signal processin
Study of annoyance due to urban automobile traffic. Annex 4: A catalog of the characteristics of noise at different measuring points
The characteristics of urban traffic were studied. Data synthesis of and data specifically for the city of Paris concerning noise due to automobile traffic were examined. Information on noise characteristics at different measuring locations is presented
An EMG study of the lip muscles during covert auditory verbal hallucinations in schizophrenia
Purpose: Auditory verbal hallucinations (AVHs) are speech perceptions in the
absence of a external stimulation. An influential theoretical account of AVHs
in schizophrenia claims that a deficit in inner speech monitoring would cause
the verbal thoughts of the patient to be perceived as external voices. The
account is based on a predictive control model, in which verbal self-monitoring
is implemented. The aim of this study was to examine lip muscle activity during
AVHs in schizophrenia patients, in order to check whether inner speech
occurred. Methods: Lip muscle activity was recorded during covert AVHs (without
articulation) and rest. Surface electromyography (EMG) was used on eleven
schizophrenia patients. Results: Our results show an increase in EMG activity
in the orbicularis oris inferior muscle, during covert AVHs relative to rest.
This increase is not due to general muscular tension since there was no
increase of muscular activity in the forearm muscle. Conclusion: This evidence
that AVHs might be self-generated inner speech is discussed in the framework of
a predictive control model. Further work is needed to better describe how the
inner speech monitoring dysfunction occurs and how inner speech is controlled
and monitored. This will help better understanding how AVHs occur
Enhancing Teaching Capability Through Thailand's Teacher TV Program
This paper aims to present and discuss on the implementation of the TeacherTelevision (TV) Program, one of important strategic approaches in developing teaching capability of approximate 500,000 Thai teachers during 2010 - 2012. It is deemed as a highly impact teacher development innovation in the Thai educational context. The study reveals that the Program significantly assists the teachers to enhance their motivation in self-directed learning and to inspire their creativity in teaching design that leads to any classroom innovations. In this paper, an evolution of the Thai Teacher TV Program and its objectives are firstly introduced. Then, some crucial empirical data collected during the implementation period are presented for exhibiting the impact of the Program on the teachers. Last, key success factors, barriers,managerial recommendations, and a strategic framework for the policy makers in any other educational contexts arediscussed and proposed
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