Academic literature on the topic 'Indice de qualité du signal'
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Journal articles on the topic "Indice de qualité du signal":
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To, Minh Chau, and Kodjovi Gakpo Assoé. "Performance et commission de souscription des fonds mutuels canadiens." Articles 71, no. 1 (February 13, 2009): 27–52. http://dx.doi.org/10.7202/602165ar.
Abstract:
RÉSUMÉ Les frais de commission exigés des investisseurs à l’achat des parts de fonds mutuels se situent entre 0 % et 9 % du montant de l’investissement initial. Ils sont souvent considérés comme un signal de qualité ou de performance. En utilisant des mesures traditionnelles de performance (indices de Jensen, de Sharpe et de Treynor), les tests de différences statistiques de Jobson et Korkie et les données mensuelles de 226 fonds mutuels canadiens couvrant la période janvier 1981 à septembre 1987, cette étude révèle qu'il n’y a aucune relation consistante et ferme entre l’exigence de frais de commission et la performance des fonds mutuels. L’efficience du marché des fonds mutuels est ainsi remise en question puisque les fonds mutuels ayant les frais de commission les plus élevés ne réalisent pas une performance significativement supérieure à celle des fonds sans frais.
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Mondet, F., J. H. Oddou, C. Boyer, L. Corsois, and D. Collomb. "Élaboration d’un indice de qualité anatomopathologique des biopsies prostatiques." Progrès en Urologie 19, no. 2 (February 2009): 107–11. http://dx.doi.org/10.1016/j.purol.2008.07.007.
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FOKA TAGNE, Alain Gilles. "Impact du comportement des auditeurs sur la qualité de services offerts dans le cadre de leur mission." Journal of Academic Finance 10, no. 2 (December 30, 2019): 2–27. http://dx.doi.org/10.59051/joaf.v10i2.160.
Abstract:
Cet article vise un double objectif. Le premier est de construire un indice qualité d’audit qui puisse discriminer les cabinets effectuant des audits de moindre qualité des audits de bonne qualité. Le second s’attèle à vérifier s’il existe une relation entre le comportement des producteurs d’opinion et l’indice qualité d’audit ainsi construit. Pour atteindre ces objectifs, nous avons collecté par questionnaire les données auprès de 60 cabinets d’audit au Cameroun. Après analyse des données par les techniques d’analyses factorielles (ACP), de corrélation de Pearson et de régression logistique, il ressort en premier lieu que la qualité d’audit est altérée au Cameroun suite à une forte proportion de cabinet produisant des audits de moindre qualité (53,3%). En second lieu, il ressort que cette mauvaise qualité d’audit est la résultante du comportement des auditeurs (ils travaillent sur les éléments qu’ils jugent significatifs, pratiquent l’incompatibilité dans le service, ne respectent pas le budget temps, manquent d’expérience).
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Messager, V., A. Portmann, J. F. Muir, and C. Letellier. "Estimation de la qualité relative du sommeil par un Indice de Qualité Globale du Sommeil." Médecine du Sommeil 11, no. 1 (January 2014): 30. http://dx.doi.org/10.1016/j.msom.2014.01.070.
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Fawzi, B., M. Chlaida, S. Oubraim, M. Loudiki, B. Sabour, and A. Bouzidi. "Application de certains indices diatomiques à un cours d'eau marocain : Oued Hassar." Revue des sciences de l'eau 14, no. 1 (April 12, 2005): 73–89. http://dx.doi.org/10.7202/705410ar.
Abstract:
Les eaux de l'Oued Hassar (Maroc) sont caractérisées par une forte minéralisation. La conductivité, variant entre 3470 et 7210 µS.cm-1, est due essentiellement aux fortes teneurs en chlorures. L'examen de l'Indice de Pollution Organique (IPO) montre que l'effluent d'eaux usées provenant de la ville de Mediouna constitue la principale source de pollution des eaux de l'Oued Hassar. Concernant l'étude des diatomées épilithiques, 61 espèces et variétés de diatomées ont été inventoriées. Ces taxons sont liés particulièrement à la salinité (Pleurosira laevis, Fragilaria pulchella,…) et à la charge organique (Nitzschia palea, Gomphonema parvulum,…). Quatre indices diatomiques ont été testés pour l'évaluation de la qualité des eaux de l'Oued Hassar : l'Indice Diatomique Pratique (IDP), l'Indice Diatomique Générique (IDG), l'Indice de Sládecek (SLA) et l'Indice Diatomique Trophique (IDT). La variation spatio-temporelle de ces indices reflète bien la dégradation de la qualité de ce cours d'eau, particulièrement en aval du rejet de la ville de Mediouna (IDP=3,86 ± 1,84 ; IDG=6,05 ± 1,95 ; SLA=4,35 ± 1,93 ; IDT=5,80 ± 1,31). Parmi ces indices testés, seul l'IDP présente une corrélation significative (0,63 ; α<5%) avec l'IPO (indice de référence) tandis que l'IDG, le SLA et l'IDT montrent des corrélations non significatives avec cet indice (0,38 ; 0,27 et -0,11 respectivement).
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Flórez, Jorge, Cristian Arenas, and Emrio Mesa. "Análisis de la situación de pobreza en Medellin a partir de la encuesta de calidad de vida, 2004-2005." Lecturas de Economía, no. 70 (September 11, 2009): 191–222. http://dx.doi.org/10.17533/udea.le.n70a2261.
Abstract:
Este trabajo analiza los resultados de las Encuestas de Calidad de Vida 2004 y 2005 en Medellín, para determinar los avances en desarrollo humano y calidad de vida de la ciudad durante la administración Fajardo hasta 2006. Este análisis se enmarca en la teoría de la pobreza desde el enfoque del desarrollo humano, hace un análisis por componentes del IDH e ICV, y una crítica al diseño de la encuesta de calidad de vida de Medellín, y finalmente, calcula el índice de pobreza humana del PNUD como un indicador complementario. El artículo corrobora que es muy difícil notar mejoras en la pobreza entre un año y otro y destaca el esfuerzo de la Alcaldía al generar un mecanismo de información en este tema. Palabras clave: Desarrollo humano, pobreza, índice de desarrollo humano, índice de calidad de vida, índice de pobreza humana. Clasificación JEL: I32, O15. Abstract: This work analyses the results of the Standard of Living Surveys (SFSs) conducted in Medellín during 2004 and 2005 in order to establish the city's advances in human development and standard of living in the administration period of former mayor Sergio Fajardo up to 2006. This article is framed into the human development poverty theory. It disentangles both the Human Development Index and the Standard of Living Index by components. Also, it makes a criticism to the design of the SFS in Medellín. And, finally, it computes UNDP's Human Poverty Index as a complementary measure. The article concludes that it is very difficult to identify changes in poverty from one year to the other and recognizes the municipal government's effort for generating an information mechanism on this issue. Keywords: Human development, poverty, Human Development Index, Standard of Living Index, human poverty index. JEL Classification: I32, O15. Résumé : Cet article analyse les résultats de l'Enquête de Qualité de Vie pour la ville de Medellín pour les années 2004 et 2005. Cette analyse permet de déterminer les progrès en matière de développement humain et qualité de vie pendant la gestion du Monsieur le Maire Sergio Fajardo jusqu'à en 2006. Dans le cadre de la théorie de la pauvreté dans l'approche du développement humain, nous présentons une analyse par les composants de l'Indice de Développement Humain (IDH) et de l'Indice de Qualité de Vie (IQV), une critique à la conception de l'Enquête de Qualité de Vie de Medellín, et finalement, nous calculons l'indice de pauvreté humaine du PNUD comme un indicateur complémentaire de notre analyse. L'article renforce l'idée selon laquelle il est très difficile d'apercevoir des améliorations substantielles dans les niveaux pauvreté d'une année à l'autre, mais nous soulignons les efforts importants de la Mairie de la ville pour produire les mécanismes d'informations à ce sujet. Mots clé: Développement humain, pauvreté, indice de développement humain, indice de qualité de vie, indice de pauvreté humaine. Classification JEL : I32, O15.
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Baker, Stephanie, Wei Xiang, and Ian Atkinson. "Determining respiratory rate from photoplethysmogram and electrocardiogram signals using respiratory quality indices and neural networks." PLOS ONE 16, no. 4 (April 8, 2021): e0249843. http://dx.doi.org/10.1371/journal.pone.0249843.
Abstract:
Continuous and non-invasive respiratory rate (RR) monitoring would significantly improve patient outcomes. Currently, RR is under-recorded in clinical environments and is often measured by manually counting breaths. In this work, we investigate the use of respiratory signal quality quantification and several neural network (NN) structures for improved RR estimation. We extract respiratory modulation signals from the electrocardiogram (ECG) and photoplethysmogram (PPG) signals, and calculate a possible RR from each extracted signal. We develop a straightforward and efficient respiratory quality index (RQI) scheme that determines the quality of each moonddulation-extracted respiration signal. We then develop NNs for the estimation of RR, using estimated RRs and their corresponding quality index as input features. We determine that calculating RQIs for modulation-extracted RRs decreased the mean absolute error (MAE) of our NNs by up to 38.17%. When trained and tested using 60-sec waveform segments, the proposed scheme achieved an MAE of 0.638 breaths per minute. Based on these results, our scheme could be readily implemented into non-invasive wearable devices for continuous RR measurement in many healthcare applications.
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Sinave, Emily, and Amélie Grégoire Taillefer. "Caractérisation et protection de l’habitat du poisson dans la rivière Beaudette (Québec)." Le Naturaliste canadien 142, no. 3 (August 28, 2018): 73–87. http://dx.doi.org/10.7202/1051000ar.
Abstract:
La rivière Beaudette est un lieu de fraie pour diverses espèces de poissons et un sanctuaire de pêche important pour la région de Vaudreuil-Soulanges. Toutefois, elle subit diverses dégradations à la suite du lessivage de sédiments provenant des activités agricoles environnantes et de la dénaturalisation des berges en milieu résidentiel. Le but de cette étude était d’acquérir des connaissances sur le bassin versant de la rivière Beaudette (Québec) afin de documenter les menaces affectant le potentiel de l’habitat du poisson. Ceci s’est fait en caractérisant l’habitat, en évaluant la qualité des bandes riveraines, en analysant la qualité de l’eau, en recensant les marques d’érosion des rives et par des inventaires ichtyologiques. Les analyses de la qualité de l’habitat du poisson indiquent que près de 75 % de la rivière obtient une cote variant de « faible » à « très faible ». De plus, la rivière obtient généralement un indice « faible » en ce qui concerne sa capacité à accomplir ses fonctions écologiques. L’inventaire ichtyologique démontre que la rivière Beaudette comprend une richesse spécifique qui est plus grande en présence de bandes riveraines de bonne qualité ainsi qu’à des valeurs élevées de l’indice de qualité de l’habitat du poisson. Ces résultats confirment le besoin d’intervenir pour assurer la pérennité des écosystèmes de la rivière Beaudette.
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Diakite, Kahirou, Saloum Diagouraga, Mamady Diawara, and Mah Fane. "Etude des paramètres physico-chimiques des huiles de graine de coton produites en zone CMDT au Mali." International Journal of Biological and Chemical Sciences 16, no. 3 (August 30, 2022): 1320–30. http://dx.doi.org/10.4314/ijbcs.v16i3.33.
Abstract:
La problématique des huiles alimentaires consommées au Mali est une question qui préoccupe les autorités. Après la fermeture de l’Usine d’Huilerie Cotonnière du Mali (HUICOMA), une centaine d’opérateurs économiques s’était implantée dans ce créneau. Aujourd’hui, le marché est inondé d’huile de coton de mauvaise qualité. Cette étude a été menée dans le but d'apprécier la qualité de l'huile raffinée produite par douze unités de production d’huile de graines de coton. L’objectif était d’analyser des paramètres physicochimiques de l’huile de coton raffinée produite par les petites unités de production de la zone CMDT au Mali. Apres échantillonnage et analyse des paramètres selon les normes du Codex Alimentarius. Les résultats suivants ont été obtenu : indice de réfraction 100% non-conforme ; densité: 100% conforme ; l’indice de peroxyde : 36,67% conforme ; Indice d’acide : 85% conforme ; teneurs en savon: 100% conforme ; indice d’iode 37,10 à 48,50 g d’I2/100g ; indice de saponification 85% non-conforme ; les matières insaponifiables 100% conforme ; traces de gossypol, 75% non conforme. Ces résultats ont montré que certaines huiles étaient préjudiciables pour la santé des consommateurs. Des investigations, notamment au niveau des chaînes technologiques d’extraction et de conditionnement des huiles dans ces unités seraient nécessaire.
The issue of edible oils consumed in Mali is a matter of concern to the authorities. After the closure of the cotton oil mill in Mali (HUICOMA), a hundred economic operators had established themselves in this niche. Today the market is flooded with poor quality cottonseed oil. This study was conducted in order to assess the quality of the refined oil produced by twelve cottonseed oil production units. The objective was to analyze the physicochemical parameters of refined cottonseed oil produced by small production units. After sampling and analysis of the parameters according to Codex Alimentarius standards, the following results were obtained: refractive index 100% non-compliant; density: 100% compliant; the peroxide index: 36.67% compliant; Acid number: 85% compliant; soap content: 100% compliant; iodine number 37.10 to 48.50 g of I2/100g; saponification index 85% non-compliant; unsaponifiable matter 100% compliant; traces of gossypol, 75% non-compliant. These results showed that certain oils were detrimental to the health of consumers. Investigations, particularly at the level of technological chains for the extraction and packaging of oils in these units would be necessary.
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Ouaffai, A., L. Dahloum, A. Fassih, M. Milagh, and M. Halbouche. "Performances de croissance, de ponte et qualité de l’œuf chez la caille Japonaise (Coturnix coturnix japonica)." Archivos de Zootecnia 67, no. 258 (April 15, 2018): 168–76. http://dx.doi.org/10.21071/az.v67i258.3651.
Abstract:
Le présent travail a consisté à étudier les performances de croissance (durant 6 semaines) et de ponte (9ème-12ème semaine) de Coturnix coturnix japonica ainsi que la qualité interne et externe des œufs. Au total, 300 cailleteaux de 1 jour d’âge ont été menés au sol. Á 6 semaines d’âge, le poids vif (PV) moyen a été de 162g avec un indice de consommation de 3,59. Les mensurations effectuées à l’âge de 8 semaines ont montré un dimorphisme sexuel significatif (P
Dissertations / Theses on the topic "Indice de qualité du signal":
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Cherif, Safa. "Effective signal processing methods for robust respiratory rate estimation from photoplethysmography signal." Thesis, Ecole nationale supérieure Mines-Télécom Atlantique Bretagne Pays de la Loire, 2018. http://www.theses.fr/2018IMTA0094/document.
Abstract:
Le photopléthysmogramme (PPG) est un signal optique acquis à partir de l’oxymètre de pouls, dont l’usage principal consiste à mesurer la saturation en oxygène. Avec le développement des technologies portables, il est devenu la technique de base pour la surveillance de l’activité cardio-respiratoire des patients et la détection des anomalies. En dépit de sa simplicité d'utilisation, le déploiement de cette technique reste encore limité pour deux principales raisons : 1. L’extrême sensibilité du signal aux distorsions. 2. La non-reproductibilité entre les sujets et pour les mêmes sujets, en raison de l'âge et des conditions de santé. L’objectif de cette thèse est le développement de méthodes robustes et universelles afin d’avoir une estimation précise de la fréquence respiratoire (FR) indépendamment de la variabilité intra et interindividuelle du PPG. Plusieurs contributions originales en traitement statistiques du signal PPG sont proposées. En premier lieu, une méthode adaptative de détection des artefacts basée sur la comparaison de modèle a été développée. Des tests par la technique Random Distortion Testing sont introduits pour détecter les pulses de PPG avec des artefacts. En deuxième lieu, une analyse de plusieurs méthodes spectrales d’estimation de la FR est proposée. Afin de mettre en évidence la robustesse des méthodes proposées face à la variabilité du signal, plusieurs tests ont été effectués sur deux bases de données avec de différentes tranches d'âge et des différents modes respiratoires. En troisième lieu, un indice de qualité respiratoire spectral (SRQI) est conçu dans le but de communiquer au clinicien que les valeurs fiables de la FR avec un certain degré de confianceOne promising area of research in clinical routine involves using photoplethysmography (PPG) for monitoring respiratory activities. PPG is an optical signal acquired from oximeters, whose principal use consists in measuring oxygen saturation. Despite its simplicity of use, the deployment of this technique is still limited because of the signal sensitivity to distortions and the non-reproducibility between subjects, but also for the same subject, due to age and health conditions. The main aim of this work is to develop robust and universal methods for estimating accurate respiratory rate regardless of the intra- and inter-individual variability that affects PPG features. For this purpose, firstly, an adaptive artefact detection method based on template matching and decision by Random Distortion Testing is introduced for detecting PPG pulses with artefacts. Secondly, an analysis of several spectral methods for Respiratory Rate (RR) estimation on two different databases, with different age ranges and different respiratory modes, is proposed. Thirdly, a Spectral Respiratory Quality Index (SRQI) is attributed to respiratory rate estimates, in order that the clinician may select only RR values with a large confidence scale. Promising results are found for two different databases
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Khreis, Soumaya. "Fusion par lisseur de Kalman pour l’estimation de la fréquence respiratoire à partir de l’électrocardiogramme ou du photoplethysmogramme." Thesis, Rennes 1, 2019. http://www.theses.fr/2019REN1S047/document.
Abstract:
Ce mémoire de thèse vise à proposer de nouvelles méthodes robustes pour l'estimation de la fréquence respiratoire (FR) à partir des signaux physiologiques souvent utilisés dans la clinique comme l'électrocardiogramme (ECG) ou le photoplethysmogramme (PPG), tout en évitant de porter des capteurs encombrants et inconfortables. En effet, la respiration influence les signaux ECG et/ou PPG. Plusieurs modulations qui décrivent la respiration sont extraites basée principalement sur l'amplitude, la fréquence et la ligne de base. Il est toutefois difficile de déterminer la combinaison optimale des modulations pour obtenir une estimation précise de la FR en raison du bruit, la spécificité de chaque patient et de l'activité. Après une revue de la littérature, il ressort que peu de travaux ont étudié la qualité de ces modulations. Nous proposons donc de quantifier la qualité des modulations à l'aide d'indices de qualité respiratoire (IQR), un nouvel indice basé sur une modulation sinusoïdale est introduit. Puis, deux méthodes sont proposées: la première sélectionne automatiquement la modulation avec l'IQR le plus élevé pour une estimation de la FR, la seconde combine les deux meilleurs modulations avec le lisseur de Kalman (LK). Une nouvelle approche de fusion de modulations basée sur un modèle multimodale est également explorée. Ces méthodes sont évaluées sur trois bases de données de différents contextes cliniques: la surveillance dans les soins postopératoires (où les patients sont immobiles), le suivi pendant les activités physiques quotidiennes et la surveillance néonatale. Les résultats expérimentaux montrent que les IQRs associés à un algorithme de fusion augmentent la précision de l'estimation de la FR à partir des modulations dérivées et montrent des résultats supérieurs aux travaux issus de la littératureThe presented work in this dissertation concerns the development of approaches to estimate the breathing rate (BR) accurately from the electrocardiogram (ECG) and photoplethysmogram (PPG), to avoid wearing cumbersome and uncomfortable sensors for direct measurements. In fact, the respiration influences ECG and PPG signals. Several modulations are extracted to describe breathing cycles based on amplitude, frequency and baseline. However, it is difficult to determine the optimal combination to estimate the BR due to the noise and patient-dependency. Since few works have studied the quality of these modulations, we propose to study the quality of modulations using respiratory quality indices (RQI). To do so, we present two methods: the first automatically selects the modulations with the highest RQI for BR estimation, the second tracks the respiration signal using Kalman smoother. The obtained results show superior performance comparing to the methods in the literature. In addition, an extension of fusion approach is presented based on a multi-mode model. These proposed methods are tested on several datasets with different clinical contexts: monitoring post-operative care (where patients are immobile), daily physical activities and neonatal monitoring. The experimental results show that the RQIs coupled with a fusion algorithm increase the accuracy of the BR estimation from the derived modulations
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Chehbani, Amel. "Etude et mise en œuvre d’un système communicant sans fil et sans radio pour la mesure de paramètres physiologiques des nouveau-nés." Electronic Thesis or Diss., Limoges, 2024. http://www.theses.fr/2024LIMO0009.
Abstract:
La fragilité du système immunitaire chez les personnes âgées, les nouveau-nés et les prématurés augmente leur susceptibilité aux maladies cardiovasculaires et à l’insuffisance cardiaque. En effet, les symptômes des pathologies cardiaques peuvent être très inhabituels et sporadiques chez cette population. Cela nécessite donc un suivi continu de l’activité cardiaque par l’électrocardiogramme (ECG) qui permet une détection précoce des anomalies. Classiquement, les systèmes ECG sont filaires limitant le suivi continu et le confort des patients. Grace à la technologie, des systèmes ECG portables et sans fil ont été également développés en se basant principalement sur des technologies radio fréquences (RF) efficaces, ce qui permet à ces utilisateurs d’être suivis régulièrement. Cependant, les exigences de sécurité et de confidentialité, la génération d'interférences, les effets néfastes potentiels sur la santé des patients, la congestion du spectre ainsi que l'efficacité énergétique sont des défis pour le déploiement massif des technologies RF dans les scénarios de la santé. Plutôt que se plier aux limitations des systèmes RF, cette thèse se penche sur une solution alternative basée sur les technologies de l’optique sans fil qui permettent des communications sécurisées et écoresponsables. Cette solution consiste en un système de surveillance utilisant une liaison infrarouge entre un émetteur intégrée dans un capteur ECG placé sur le corps de l’utilisateur et des récepteurs placés au plafond de l’environnement. Afin d’étudier les trois contextes de surveillance, le canal optique correspondant a été simulé à l’aide d’une technique de lancer des rayons, associée à la méthode numérique de Monte-Carlo. En tenant compte des spécificités liées au scénario de surveillance, à la population (âge et mobilité) et à l’environnement modélisé (matériau transparent des incubateurs des prématurés), le gain statique caractérisant le canal est ainsi obtenu. Ce gain a été utilisé dans une chaine développée pour simuler la transmission de l’ECG dans chaque contexte. La fiabilité du système de télésurveillance proposé est ainsi conditionnée par la qualité de l’ECG transmis qui a été évaluée au niveau applicatif à l’aide de la méthode des indices de qualité du signal (SQIs). Les SQIs consistent à extraire les caractéristiques spectrales et statistiques de l'ECG. De plus, vu son utilité dans le suivi du développement des prématurés, la variabilité de la fréquence cardiaque (VFC) a été également analysée par le calcul des paramètres temporels qui caractérisent les intervalles RR. L’objectif principal consiste à évaluer l'impact des performances de transmission optique sur les indices de qualité SQIs. À cette fin, une approche d’analyse générale a été mise en œuvre pour étudier conjointement l’évolution des (SQIs) et des paramètres temporels de la (VFC) au niveau applicatif en fonction des métriques classiques au niveau physique, à savoir (SNR) et (TEB). Les résultats de cette recherche ont montré le potentiel de l’utilisation de l’optique sans fil dans de tels contextes médicaux pour proposer une solution fiable et économe en énergie. En effet, dans les trois cas d’étude, des signaux ECG de qualité suffisante pour des diagnostics fiables ont été obtenus à des niveaux de puissance optique émise modérés, ce qui est important pour un système de télésurveillance médicale portableThe weak immune systems in the elderly, newborns and preterm infants increase their susceptibility to cardiovascular disease and heart failure. Indeed, symptoms of cardiac pathology can be quite unusual and sporadic in this population. This requires continuous monitoring of cardiac activity by electrocardiogram (ECG), which enables early detection of abnormalities. Conventionally, ECG systems are wired, limiting continuous monitoring and patient comfort. Thanks to technology, portable and wireless ECG systems have also been developed, based mainly on efficient radio frequency (RF) technologies, which enable these users to be monitored regularly. However, security and privacy requirements, interference generation, potential harmful effects on patient health, spectrum congestion and energy efficiency are challenges for the massive deployment of RF technologies in healthcare scenarios. Instead of relying on the limitations of RF systems, this thesis focuses on an alternative solution based on optical wireless technologies that enable safe and environmentally-friendly communications. This solution consists of a monitoring system using an infrared link between a transmitter embedded in an ECG sensor placed on the user's body and receivers placed on the ceiling of the environment. In order to study the three monitoring contexts, the corresponding optical channel was simulated using a ray-tracing technique combined with the numerical Monte-Carlo method. Considering the specificities of the monitoring scenario, the population (age and mobility) and the modeled environment (transparent material of premature baby incubators), the static gain characterizing the channel was obtained. This gain was used in a chain developed to simulate ECG transmission in each context. The reliability of the proposed remote monitoring system is thus conditioned by the quality of the transmitted ECG signal. This has been assessed at application level using the Signal Quality Index (SQI) method, which consists in extracting spectral and statistical characteristics from the ECG. In addition, given its usefulness in monitoring the development of premature infants, heart rate variability (HRV) has also been analyzed by computing the temporal parameters that characterize RR intervals in an ECG. The main objective is to assess the impact of time-varying optical transmission performance on the quality of the received ECG signal, in order to design a less intrusive, reliable and cost-effective system for remote ECG signal monitoring. SQIs consist in extracting spectral and statistical characteristics from the ECG. In addition, given its usefulness in monitoring the development of premature infants, heart rate variability (HRV) was also analyzed by computing the temporal parameters that characterize RR intervals. The main objective is to assess the impact of optical transmission performance on ECG quality metrics. For this purpose, a general analysis approach was implemented to jointly study the evolution of (SQIs) and VFC temporal parameters at the application level as a function of classical metrics at the physical level, namely (SNR) and (BER). The results of this research showed the potential of using wireless optics in such medical contexts to provide a reliable and energy-efficient solution. Indeed, in all three cases investigated, ECG signals of sufficient quality for reliable diagnoses were obtained at moderate levels of transmitted optical power, which is important for a portable medical remote monitoring system
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Ouzennou, Hakim. "Indice de qualité de station des pessières noires irrégulières." Thesis, Université Laval, 2007. http://www.theses.ulaval.ca/2007/24648/24648.pdf.
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Linnemer, Laurent. "Publicité et signal de la qualité." Paris, EHESS, 1996. http://www.theses.fr/1996EHES0037.
Abstract:
Dans une situation ou les consommateurs peuvent etre trompes sur la qualite des produits, nous explorons le role de signal d'une publicite purement dissipative. Nous renforcons l'explication issue des travaux de p. Nelson (1974) dans laquelle la publicite est motivee par la perspective d'achats repetes. Nous elargissons ce point de vue en montrant que d'autres effets de long terme tels l'investissement en capacites de production ou la courbe d'apprentissage poussent aussi a l'usage d'une publicite dissipative a des fins de signal. Nous degageons le role de barriere a l'entree de la publicite en fusionnant le modele statique de signal de la qualite avec un modele de prix limite. Enfin, nous soulignons que la publicite dissipative est un signal efficace lorsque la caracteristique a signaler est multidimensionnelleIn a context of an experience quality good, we reinforce the role of dissipative advertising as a signal of product quality by analysing a two period model. The conclusions of nelson (1974) are strengthened. Next, we widen this point of view, showing that other long term effects such as investment in capacity or learning by doing induce to the use of dissipative advertising. We extract the role of barrier of entry of advertising in merging the static model of quality signal and a model of limit pricing. Finally, we highlight that dissipative advertising is an efficient signal when the hidden characteristic is multidimensional
6
Novanda, Happy. "Monitoring of power quality indices and assessment of signal distortions in wind farms." Thesis, University of Manchester, 2012. https://www.research.manchester.ac.uk/portal/en/theses/monitoring-of-power-quality-indices-and-assessment-of-signal-distortions-in-wind-farms(403a470c-279a-4b00-94dc-eaa2507dc579).html.
Abstract:
Power quality has become one of major concerns in the power industry. It can be described as the reliability of the electric power to maintain continuity operation of end-use equipment. Power quality problems are defined as deviation of voltage or current waveforms from the ideal value. The expansion plan of wind power generation has raised concern regarding how it influences the voltage and current signals. The variability nature of wind energy and the requirements of wind power generation increase the potential problems such as frequency and harmonic distortions. In order to analyze and mitigate problems in wind power generation, it is important to monitor power quality in wind farm. Therefore, the more accurate and reliable parameter estimation methods suitable for wind power generation are needed. Three parameter estimation methods are proposed in this thesis to estimate the unknown parameters, i.e. amplitude and phase angle of fundamental and harmonic components, DC component and system frequency, during the dynamic change in wind farm. In the first method, a self-tuning procedure is introduced to least square method to increase the immunity of the algorithm to noise. In the second method, nonrecursive Newton Type Algorithm is utilised to estimate the unknown parameters by obtaining the left pseudoinverse of Jacobian matrix. In the last technique, unscented transformation is used to replace the linearization procedure to obtain mean and covariance which will be used in Kalman filter method. All of the proposed methods have been tested rigorously using computer simulated data and have shown their capability to track the unknown parameters under extreme distortions. The performances of proposed methods have also been compared using real recorded data from several wind farms in Europe and have demonstrated high correlation. This comparison has verified that UKF requires the shortest processing time and STLS requires the longest.
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Stronach, Natalie. "Élaboration d'un indice global de qualité de l'environnement urbain pour la ville de Sherbrooke." Mémoire, Université de Sherbrooke, 2004. http://savoirs.usherbrooke.ca/handle/11143/2392.
Abstract:
The growing urbanization rates throughout the world have negative effects on the natural environment of urban areas. However, there are very little means to measure the global quality of the environment in urban areas.The goal of this project is to realize a quantitative evaluation of the quality of the urban environment using ten environmental indicators for 47 sectors of the city of Sherbrooke. Then, each indicator is weighted and three indexes are created.The sectors with high quality environmental characteristics are clearly identified. In Sherbrooke, the center of town has a poor environmental index whereas the surrounding areas display a higher overall quality.The vegetation indicators extracted from high resolution satellite imagery account for an important part of the variation of the global index (r[superscript 2] = 0.85). Thus, remote sensing is an appropriate and effective way to evaluate the quality of the urban environment in Sherbrooke.
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Montard, Nathalie. "Estimation de la qualité perceptuelle de signaux numériques audiovisuels : de la qualité à l'acceptabilité du service." Saint-Etienne, 2001. http://www.theses.fr/2002STET4009.
Abstract:
Le développement des technologies numériques et du paysage multimédia amène de nombreux nouveaux services, de nouveaux types de terminaux et de nouvelles conditions de diffusion de ces services. Ces évolutions entraînent également l'évolution des techniques de surveillance de la qualité audiovisuelle et des procédés de qualification de la qualité du service. De nombreuses méthodes d'estimation de la qualité de signaux numériques sont apparues ces dernières années. Cependant, ces méthodes ne permettent pas toujours de répondre aux contraintes de la surveillance d'un réseau de diffusion en temps réel et en continu. De plus, ces techniques permettent de qualifier le signal audio ou vidéo sans rendre compte de la qualité globale du service tel qu'il est abordé par l'utilisateur. Cette thèse propose des solutions pour l'intégration des informations perceptuelle audio et vidéo dans le but de qualifier l'ensemble d'un service audiovisuel. L'approche adoptée est orientée utilisateur final, c'est à dire qu'elle prend également en compte l'intégration du temps et le contexte de l'exploitation du service. Les méthodes développées utilisent la modélisation de phénomènes psychophysiques des interactions perceptuelles audio et vidéo, ainsi que l'influence de la mémoire perceptuelle et du temps. Cette thèse présente également un modèle d'estimation aveugle de la qualité vidéo au moyen de paramètres sensibles à différents types de dégradations. Ces paramètres exploitent simultanément des données fréquentielles et spatiales et sont fusionnés par un modèle non linéaire d'estimation de qualité perceptuelle. Les phases de simulation ont permis de valider la pertinence des procédés de mesure. 2 applications ont permis la mise en œuvre de ces solutions sur des plates-formes de traitement du signal. Les développements réalisés lors de ces recherches ont fait l'objet de plusieurs brevetsThe development of digital technologies and multimedia landscape has led to the creation of several new services, a nex generation of terminals and new broadcasting conditions. These changes bring about new audio-visual monitoring techniques and re-open the whole question of the assessment of quality of service. . . [etc. ]
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Burlacu, Radu. "Emission d'obligations convertibles : un signal riche sur la qualité de l'entreprise." Grenoble 2, 2000. http://www.theses.fr/2000GRE21050.
Abstract:
Malgrè l'ancienneté et l'importance croissante des obligations convertibles, leur rôle reste encore mal connu. Les théories actuelles modélisent ces titres en tant que versions déguisées de financements classiques et leurs prédictions sont contredites par de nombreux résultats empiriques sur les marchés internationaux. Dans une première partie, nous proposons une extension du modèle de Myers et Maijluf (1984) pour expliquer les décisions de financement et d'investissement avec obligations convertibles. L'originalité de notre approche provient de la modélisation explicite des asymétries informationnelles sur les deux dimensions de l'entreprise, sa valeur espérée et son risque. Le contexte privilégie la composante optionnelle des titres. Les entreprises dont le risque est surestimé émettent des convertibles à forte option de conversion car cette dernière est surévaluée. Au contraire, les entreprises dont le risque est sous-estimé émettent des convertibles assorties de clause de remboursement anticipé. Cette approche permet d'expliquer, pour la première fois l'existence de deux types de convertibles dans un cadre unifié. Dans la deuxième partie, nous testons notre modèle en confrontant ses prédictions avec les résultats empiriques. L'originalité de notre approche est de positionner les convertibles dans un système à trois dimensions (action, obligation et option) par le Delta de ces titres. La revue des résultats empiriques sur les marchés internationaux démontre que la dimension "optionnelle" des convertibles joue un rôle prépondérant pour les dirigeants et les investisseurs. Notre recherche met en évidence le rôle des convertibles dans des configurations peu analysées par la littérature actuelle et correspondant mieux à leur vraie utilisation. Les convertibles augmentant l'efficience du marché et permettent la réalisation de projets rentables dans des contextes ou les titres classqiues, leur combinaison ou d'autres titres hybrides restent inefficients.
10
Barrette, Valérie. "Élaboration d'un indice global de qualité de vie par intégration de données multisources cas de la Ville de Sherbrooke." Mémoire, Université de Sherbrooke, 2003. http://savoirs.usherbrooke.ca/handle/11143/2367.
Abstract:
Résumé : Le milieu urbain suscite un grand intérêt pour plusieurs chercheurs et est une source riche en information de tout genre. Ce travail se situe donc dans l'ensemble des études urbaines et s'intéresse à la qualité de vie des gens qui habitent la ville. Avec les données issues de la télédétection ainsi que les caractéristiques socio-démographiques des populations, il est possible, par intégration dans un SIG, d'évaluer la qualité de vie des citadins. L'étalement des hommes sur le territoire urbain, selon leurs besoins et leurs désirs, provoque une ségrégation des groupes sociaux et ainsi une importante variation du niveau de vie au sein d'une même ville. L'étude de cette variation de la qualité de vie en milieu urbain est possible par la mise en relation d'indicateurs objectifs reliés au bien-être social, à la vitalité économique et à l'intégrité environnementale. L'objectif de cette étude est donc d'évaluer la qualité de vie en milieu urbain par la création d'un indice global de qualité de vie pour les 22 unités de voisinage de la Ville de Sherbrooke. Trois sources de données différentes permettent d'obtenir ces indicateurs, il s'agit des images hautes résolutions du satellite IKONOS, des statistiques du recensement de 1996 ainsi que certaines données provenant des relevés municipaux. Par une intégration de toutes ces données dans un SIG, il est possible de produire une cartographie de la variation de la qualité de vie sur l'ensemble du territoire de la Ville de Sherbrooke. Chacun des neuf indicateurs retenus possède un poids différent dans la composition de l'indice global. Trois cartes représentant l'indice global de qualité de vie ont été produites selon les trois pondérations différentes. Comparés avec la réalité-terrain, il est ensuite possible de déterminer la meilleure pondération identifiant la situation réelle sur le territoire. Les résultats sont très satisfaisants et on remarque l'apport très intéressant des images de la télédétection qui permettent de définir trois indicateurs différents et ainsi d'innover dans ce domaine. Les détails offerts par la haute résolution permettent d'exploiter au maximum certaines caractéristiques urbaines.||Abstract : The urban environment contents a lot of interesting information and it's an important source of inspiration for many researchers. This study goes in that way and has a special interest for the urban quality of life. With the GIS possibilities, the data from remote sensing and the socio-demographic measurements for the urban populations, can be integrated. The quality of life in the urban areas can be quantified. The rapid urbanisation and the sprawl of the humans in the cities, cause an important segregation of the different socials groups. So, the quality of life in a same territory is very different. This variation of the quality of life can be studied by the integration of indicators link to social well-being, economic vitality and environmental integrity. The objective of this project is to evaluate the quality of life for the 22 divisions in the city of Sherbrooke. The data come from three different sources: high spatial resolution IKONOS numeric imagery, statistics from 1996 census and some information form municipality resources. By integrated all of this information in a GIS, it is possible to produce a cartographic representation for the variation of the quality of life on this territory. Every indicator in the global indicator has a different weight of importance. Three different maps for three different weighting has been produce. A comparison with the real situation on the territory has been done to evaluate the choice of the indicators and the methodology. The results are satisfying and the very interesting contribution of the high-resolution imagery is demonstrated. The details offer with these images involves a maximum development in the use of urban characteristics.
Books on the topic "Indice de qualité du signal":
1
Koons, George. Indices of capability: Classical and six sigma tools. Reading, Mass: Addison-Wesley Pub. Co., 1992.
2
Projet de recherche sur les politiques (Canada), ed. Indice canadien de la durabilité des ressources hydriques (ICDRH): Rapport de projet. Ottawa, Ont: Projet de recherche sur les politiques, 2007.
3
Félice, Éric. Qualité des réseaux électriques et efficacité énergétique. Paris: Dunod, 2009.
4
Osberg, Lars. Un indice du bien-être économique pour le Canada. Hull, Qué: Développement des ressources humaines Canada, Direction générale de la recherche appliquée, 1998.
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Slater, Jim. Modern television systems: To HDTV and beyond. London: Pitman, 1991.
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Turiel, Judith Steinberg. Beyond second opinions: Making choices about fertility treatment. Berkeley: University of California Press, 1998.
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Scadding, Alys. Terminal care in respiratory illness. Edited by Patrick Davey and David Sprigings. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780199568741.003.0146.
Abstract:
The terminal phase is the period of time between living with a reasonable quality of life, and the process of dying. While lung cancer and pulmonary fibrosis have the potential to deteriorate rapidly, the majority of lung diseases worsen over years. Every exacerbation of the condition leads to a decline in both lung function and performance status, and often the pre-exacerbation level of functioning is never regained. There is not a defining point to indicate whether a patient is entering the terminal stages of their illness, but practice shows that the following signs are suggestive: increasing breathlessness and thus becoming increasingly housebound; increasing oxygen requirements; declining pulmonary function test results; increasingly frequent exacerbations requiring hospital admission and/or non-invasive ventilation; developing cor pulmonale; weight loss and difficulty maintaining weight; anxiety and depression; if the death of the patient within the next year would not be a surprise.
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The State of Democracy in the Americas 2021: Democracy in Times of Crisis. International Institute for Democracy and Electoral Assistance, 2021. http://dx.doi.org/10.31752/idea.2021.93.
Abstract:
The number of democracies in the Americas remains the same as two years ago despite the Covid-19 pandemic. In addition, most of the democracies in the region demonstrated great resilience in the face of the pandemic. Parliaments, the judiciary and the media of most democracies in the region managed to adapt and continue to exercise their control functions, even in the midst of numerous restrictions that hampered their work. However, despite the resilience that the region’s democracies displayed during the pandemic, the quality of democracy continues to deteriorate in the Americas. More than half of the democracies in Latin America and the Caribbean show signs of democratic erosion, and Brazil’s democracy has been undergoing a process of democratic decline since 2016. The State of Democracy in the Americas 2021 offers political and civil actors, as well as the international community, analysis, lessons learned and recommendations to face the challenges that democracy presents, and to consolidate and reinforce its resilience. International IDEA’s Global State of Democracy reports review the state of democracy around the world. The 2021 edition covers developments in 2020 and 2021, with democratic trends since 2015 used as a contextual reference. This report on the Americas is one of four regional Global State of Democracy reports, which, along with the Global Report, complement and cross-reference each other. The reports draw on data from the Global State of Democracy (GSoD) Indices and lessons learned from International IDEA’s on-the-ground technical assistance to understand the current democracy landscape. The 2021 reports also draw heavily on data collected by International IDEA’s Global Monitor of Covid-19ʼs Impact on Democracy and Human Rights.
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Case, Jay R. Methodists and Holiness in North America. Oxford University Press, 2017. http://dx.doi.org/10.1093/oso/9780199683710.003.0009.
Abstract:
Baptists in nineteenth-century North America were known as eager proselytizers. They were evangelistic, committed to the idea of a believers’ church in which believers’ baptism was the norm for church membership and for the most part fervent revivalists. Baptist numbers soared in the early nineteenth-century United States though at the cost of generating much internal dissent, while in Canada New Light preachers such as Henry Alline were influential, but often had to make headway against an Anglican establishment. The Baptist commitment to freedom of conscience and gathered congregations had been hardened over the centuries by the experience of persecution and that meant that they were loath to qualify the freedom of individual congregations. The chapter concentrates on exposing the numerous divisions in the Baptist family, the most basic of which was the disagreement over the nature of the atonement, which separated General (Arminian) from Particular (Calvinist) Baptists. Revivals induced further divisions between Regular Baptists who were reserved about them and Separate Baptists who saw dramatic conversions and fervent outbursts as external signs of inward grace. Calvinistic Baptists took a dim view of efforts to induce conversions as laying too much trust in human agency. Though enthusiasm for missions gripped American and Canadian Baptists alike, there were those who feared that missionary societies would erode congregational autonomy. Dissent over slavery and abolition constituted the biggest single division in North American Baptist life. Southern Baptists developed biblical defences of slavery and were annoyed at attempts to keep slaveholders out of missionary work. As a result they formed a separate denomination, the Southern Baptist Convention, in 1845. Baptists had been successful in converting black slaves and black Baptists such as the northerner Nathaniel Paul were outspoken abolitionists. In the South after the Civil War, though, blacks marched out of white denominations to form associations of their own, often with white encouragement. Finally, not the least cause of internal dissent were disputes over ecclesiology, with J.M. Graves and J.R. Pendleton, the founders of Old Landmarkism, insisting with renewed radicalism on denominational autonomy. The chapter suggests that by the end of the century, Baptists embodied the tensions in Dissenting traditions. Their dissent in the public square intensified the possibility of internal disagreement, even schism, their tradition of Christian democracy proving salvifically liberating but ecclesiastically messy. While they stood for liberty and religious equality, they were active in anti-Catholic politics and in seeking to extend state activism in society through the Social Gospel movement.
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Bullock, Ian, Jill Macleod Clark, and Joanne Rycroft-Malone, eds. Adult Nursing Practice. Oxford University Press, 2012. http://dx.doi.org/10.1093/oso/9780199697410.001.0001.
Abstract:
Adult Nursing Practice: Using evidence in care enables today's students and newly qualified nurses develop the knowledge and skills they need to deliver, and lead care tomorrow. Reflecting the principles of evidence-based care in line with the current NMC competencies, this textbook helps students learn to manage patients with common conditions and fundamental health needs so they can provide the best possible evidence-based care. Written, and edited by leading nurses from practice, education and research, it focuses on common diseases, fundamental health needs, and symptoms that nurses' encounter in daily practice. Conditions are clearly explained so that the causes of ill health are easily understood. Every chapter covers pathophysiology, indicates the key priorities for nursing assessment, and discusses 'what the evidence says', before considering nursing management options. Throughout the authors' clear signposts to trustworthy evidence mean that students can effortlessly select the best nursing interventions for their patients using the current available evidence-base. The ideal guide for students preparing for registration and newly qualified staff going through preceptorship, it is packed with over 115 illustrations and lots of features to bring the subject to life and make learning easier: BLNursing assessment illustrations outline challenges caused by common diseases in a helpful and memorable way, highlighting issues that need assessment BLRed flag icons indicate the warning signs of deterioration and urgent questions are listed that can be used for assessment and monitoring BLCase studies of effective evidence-based interventions show the difference that high quality nursing care makes BLCross references between common conditions' causes and managing related health needs and symptoms develop understanding by clearly linking pathophysiology with nursing management options BLTheory into practice boxes further enhance learning through suggested activities, such as exploring key evidence, considering major practice issues or applying core knowledge while out on placement BLOnline resource centre at www.oxfordtextbooks.co.uk/orc/bullock http://www.oxfordtextbooks.co.uk/orc/bullock. Filled with interactive and useful e-learning resources to help students test their learning, keep up-to-date with the latest evidence and further expand their knowledge, it features: BLClinical decision making scenarios BLQuiz questions BLUpdates to content BLHyperlinked references BLimages from the book BLLecturer resources
Book chapters on the topic "Indice de qualité du signal":
1
Liu, Feifei, Shoushui Wei, Fei Lin, Xinge Jiang, and Chengyu Liu. "An Overview of Signal Quality Indices on Dynamic ECG Signal Quality Assessment." In Feature Engineering and Computational Intelligence in ECG Monitoring, 33–54. Singapore: Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-3824-7_3.
2
Abdelazez, M., P. X. Quesnel, A. D. C. Chan, and H. Yang. "Signal Quality Indices for Ambulatory Electrocardiograms Used in Myocardial Ischemia Monitoring." In IFMBE Proceedings, 1076–79. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-19387-8_262.
3
Jin, Xi, Changqing Xia, Chi Xu, and Dong Li. "Mixed-Criticality Scheduling on 5G New Radio." In Mixed-Criticality Industrial Wireless Networks, 101–27. Singapore: Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-8922-3_6.
Abstract:
AbstractCompared to industrial wired networks, 5G can improve device mobility and reduce the cost of networking. However, the real-time performance and reliability of 5G NR (new radio) still need to be improved to satisfy industrial applications’ requirements. In factories, the main factor that affects the performance of 5G NR is the unstable signal quality caused by high temperatures and metal. Although assigning dedicated resources to all transmissions and retransmissions is an effective method to improve the performance of 5G NR, the unstable signal quality causes the resources required for retransmissions to be uncertain. To address the problem, we introduce the mixed-criticality task model to 5G NR. When high-criticality packets cannot be transmitted, they are allowed to preempt the resources shared with low-criticality packets. The mixed-criticality scheduling problem of 5G NR is NP-hard. We formulate it as an OMT (optimization modulo theories) specification and propose a scheduling algorithm based on bin packing methods to make 5G NR satisfy industrial applications’ requirements. Finally, we conduct extensive evaluations based on an industrial 5G testbed and random test cases. The evaluation results indicate that our algorithm makes communication reliability greater than 99.9% on unlicensed spectrum, and for most test cases, our algorithm is close to optimal solutions.
4
Chong, Changho. "Technology of SS-OCT Biometer: Argos Biometer." In Intraocular Lens Calculations, 215–28. Cham: Springer International Publishing, 2024. http://dx.doi.org/10.1007/978-3-031-50666-6_12.
Abstract:
AbstractSwept-source OCT captures an image of the whole eye from the cornea to the retina prior to cataract surgery. The measured image is used to calculate the biometric parameters necessary for IOL power calculation. Swept-source OCT technology allows two-dimensional imaging, a superior signal-to-noise ratio, and improves tissue penetration and image quality. The Argos biometer calculates axial length as the sum of physical distances of four segments: central corneal thickness, aqueous depth, lens thickness, and the thickness of vitreous humor, each calculated by dividing optical distance by corresponding refractive indices (1.375, 1.336, 1.41, 1.336) at infra-red wavelength range which implies the true physical scale of AL. The performance of the Argos biometer includes an enhanced retinal visualization, segmented axial length measurement, and enhanced OCT keratometry.
5
Smith, John Maynard, and David Harper. "Indices of quality." In Animal Signals, 45–67. Oxford University PressOxford, 2003. http://dx.doi.org/10.1093/oso/9780198526841.003.0004.
Abstract:
Abstract A crucial distinction we have tried to draw has been between ‘indices’, signals that are reliable because they cannot be faked, and ‘handicaps’, signals that are reliable because they are costly to produce. The distinction is clear enough in a model, and there are examples that fall easily into one or other category. Fights between funnel-web spiders are settled in favour of the heavier spider if the weight difference is greater than about 10 per cent. A spider can signal its weight cost-free by vibrating the web. Female stalk-eyed fiies prefer males with long eye-stalks—eye-stalk length is associated with good condition, and hence with ‘good genes’, because it would be too expensive for low quality males to grow long eye-stalks. These are examples of an index, and a handicap, respectively.
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Smith, John Maynard, and David Harper. "The evolution of signal form." In Animal Signals, 68–89. Oxford University PressOxford, 2003. http://dx.doi.org/10.1093/oso/9780198526841.003.0005.
Abstract:
Abstract So far, we have had rather little to say about the form of signals. In Chapter 2, we were concerned primarily with the cost of producing a signal, and the relation between the cost and reliability of the signal, but its form was ignored. In contrast, the form of an index, discussed in Chapter 3, is crucial, since an index only works if its intensity is causally tied to the quality being signalled. But many signals are not indices; we now turn to various ideas that have been proposed to explain their form.
7
Chen, Lei, and Chung-Wei Lee. "Mobile Multimedia Streaming Using Secure Multipath in Wireless Ad Hoc Networks." In Wireless Technologies, 544–64. IGI Global, 2012. http://dx.doi.org/10.4018/978-1-61350-101-6.ch304.
Abstract:
Supporting reliable and secure multimedia streaming service is a challenging task in the environment of wireless Mobile Ad hoc Networks (MANETs) where radio signals are prone to security attacks and the quality of media streaming is degraded by signal strength loss and interference. The mobility of mobile devices makes streaming even more difficult as communication links are often broken when the devices move out of the transmission range of their neighbors. This paper proposes a stable multipath routing algorithm and an intelligent secure data distribution scheme for multimedia streaming in MANETs. The multipath Neighbor Stability Routing is able to find more stable and long-lasting paths than traditional ad hoc routing algorithms. The secure data distribution takes historical data-path distribution into consideration and maximally disperses new multimedia data to reduce the possibility of information leakage to unauthorized parties. The authors’ simulation and analysis indicate that the combination of these two mechanisms can provide high quality paths to achieve secure multimedia streaming.
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Popoff, Andrey. "Quality Indices of Signal Processing in Metric Spaces with L-group Properties." In Fundamentals of Signal Processing in Metric Spaces with Lattice Properties, 207–65. CRC Press, 2017. http://dx.doi.org/10.1201/9781315104119-6.
9
Šigutová, Hana, Aleš Dolný, Michael J. Samways, Hardersen Sönke, Junior José Max Oliveira-, Leandro Juen, Khuong Van Dinh, and Jason T. Bried. "Odonata as indicators of pollution, habitat quality, and landscape disturbance." In Dragonflies and Damselflies, 371–84. 2nd ed. Oxford University PressOxford, 2022. http://dx.doi.org/10.1093/oso/9780192898623.003.0026.
Abstract:
Abstract The Odonata have well resolved taxonomy, conspicuous diurnal adults, contact with aquatic and terrestrial environments, and a broad range of environmental sensitivity across species, making them a valuable group for environmental appraisals. Odonate nymphs are commonly tested in aquatic ecotoxicological and bioaccumulation studies and often applied with other aquatic macroinvertebrate taxa in pollution-based biotic indices. Some of the more recent work aims to explain the evolutionary context of contamination risk and to increase mechanistic understanding of contaminant effects. Adults or exuviae are typically featured in habitat quality assessments with tools such as the Dragonfly Biotic Index, regional lotic quality indices, and coarse taxonomic metrics that will be especially useful in regions lacking descriptions and keys. Adults are further being used in landscape disturbance assessments where removal of non-breeding occurrences can reduce noise and strengthen signal. The future may move toward macro-ecological health assessments enabled by extensive citizen science and vulnerability trait data.
10
Dekhandji, Fatma Zohra, and Mohamed Cherif Rais. "A Comparative Study of Power Quality Monitoring Using Various Techniques." In Advances in Computer and Electrical Engineering, 259–88. IGI Global, 2021. http://dx.doi.org/10.4018/978-1-7998-4027-5.ch011.
Abstract:
In recent years, power quality (PQ) has become an increasingly major concern for both electric utilities and the end users. Accordingly, the electrical engineering community has to deal with the analysis, diagnosis, and solution of PQ issues using system approach rather than handling these issues as individual problems. This chapter describes the analysis of PQ using advanced signal processing tools represented in Hilbert and wavelet transforms (HT-WT) and artificial intelligence tools represented in artificial neural network and support vector machine (ANN-SVM) for detection and classification of power quality disturbances, respectively. These techniques were successfully simulated using LABVIEW software capabilities. The results of simulation indicate that the signal processing techniques are effective mechanisms to detect and classify power quality disturbances. At the end, the combination of WT as a tool of detection and features extraction with SVM as a classifier tool resulted as the best combination for PQ monitoring system.
Conference papers on the topic "Indice de qualité du signal":
1
Upadhyaya, Swarnabala, and Sanjeeb Mohanty. "Power Quality disturbance detection using Wavelet based signal processing." In 2013 Annual IEEE India Conference (INDICON). IEEE, 2013. http://dx.doi.org/10.1109/indcon.2013.6725992.
2
Tai, Ta Viet, Ma Pham Nhut Tan, Nguyen Minh Tri, Nguyen Viet Ha, and Tran Thi Thao Nguyen. "Signal Quality Indices Based on Gain of Amplitude Difference for Wearable ECG Signals." In 2023 International Conference on Advanced Technologies for Communications (ATC). IEEE, 2023. http://dx.doi.org/10.1109/atc58710.2023.10318870.
3
Lin, Joe Yuchieh, Tsung Jung Liu, Weisi Lin, and C. C. Jay Kuo. "Visual-saliency-enhanced image quality assessment indices." In 2013 Asia-Pacific Signal and Information Processing Association Annual Summit and Conference (APSIPA). IEEE, 2013. http://dx.doi.org/10.1109/apsipa.2013.6694328.
4
Daluwatte, Chathuri, Lars Johannesen, Loriano Galeotti, Jose Vicente, David Strauss, and Christopher Scully. "Assessing Effect of Beat Detector on Detection Dependent Signal Quality Indices." In 2016 Computing in Cardiology Conference. Computing in Cardiology, 2016. http://dx.doi.org/10.22489/cinc.2016.267-273.
5
Shi, Haotian, Zhi Zheng, Bo Wang, Yuhan Fan, and Yongxin Guo. "Signal Quality Indices Evaluation for Optimized Radar-Based Blood Pressure Monitoring." In 2023 Asia-Pacific Microwave Conference (APMC). IEEE, 2023. http://dx.doi.org/10.1109/apmc57107.2023.10439803.
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Xu, Man, Jiang Shen, and Haiyan Yu. "Multimodal data classification using signal quality indices and empirical similarity-based reasoning." In 2015 Computing in Cardiology Conference (CinC). IEEE, 2015. http://dx.doi.org/10.1109/cic.2015.7411131.
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Terzija, V., V. Stanojevic, and W. Rebizant. "Electrical power quality indices estimation during severe signal distortions in medium voltage networks." In Exposition. IEEE, 2008. http://dx.doi.org/10.1109/tdc.2008.4517182.
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Ilyass, Abouelaziz, Chetouani Aladine, Mohammed El Hassouni, and Cherifi Hocine. "Full Reference Mesh Visual Quality Assessment Using Pre-Trained Deep Network and Quality Indices." In 2019 15th International Conference on Signal-Image Technology & Internet-Based Systems (SITIS). IEEE, 2019. http://dx.doi.org/10.1109/sitis.2019.00113.
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Naik, Chirag A., and Prasanta Kundu. "New Power Quality indices based on S-transform for non-stationary signals." In 2012 IEEE International Conference on Power and Energy (PECon). IEEE, 2012. http://dx.doi.org/10.1109/pecon.2012.6450301.
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Zhao, Qichao, Ran Yang, Xiaoqing Zhu, Chunxiao Li, Xin Gao, Yanan Li, Haiyang Yu, et al. "Systematic Comparison of Signal Quality in Portable and Wearable Wireless EEG Devices: Methods and Standards." In 15th International Conference on Applied Human Factors and Ergonomics (AHFE 2024). AHFE International, 2024. http://dx.doi.org/10.54941/ahfe1004813.
Abstract:
Electroencephalography (EEG) is a technique that captures the electrical activity of the cerebral cortex, effectively reflecting various rapid cognitive processes. Traditional EEG devices, often large and bulky, are impractical for real-world applications. To address this, wearable and wireless EEG systems have been developed as cutting-edge technology. However, there remains uncertainty about their signal quality .In this study, we introduce a systematic comparison method customized for portable wireless EEG devices. This experiment includes three tasks: α-suppression, Biofeedback, and the Stroop Colour and Word Test, evaluating signal quality in both time and frequency domains. In the α-suppression task, we analyzed spectral power in the α band, Signal-to-Noise Ratio (SNR), Root Mean Square(RMS),and artifact rejection. For the biofeedback task, we evaluated Engagement (β/(α+θ)) and Relaxation (α/β) indices. We also measured the N400 amplitude during the Stroop Colour and Word Test. These indicators represent varying levels of signal quality requirements, from low to high. Additionally, to assess whether semi-dry EEG devices can match the performance of medical-grade gel electrodes, further significant difference and correlation analysis between the two types of devices were conducted. The frequency domain analysis revealed alpha suppression during eyes-open states and increased relaxation and engagement states during the biofeedback task compared to resting state. In the time domain analysis, although no statistical significance was observed in the N400 component, a clear trend of a larger N400 under inconsistent conditions was evident in waveform and topographic maps. Furthermore, difference tests and correlation analysis between the two devices demonstrated a strong positive correlation in signals and consistent performance across all tasks. These findings suggest that portable EEG devices provide reliable signal accuracy in real-world settings, the signal quality of the semi-dry electrodes used in this study is comparable to that of medical-grade gel electrodes.
Reports on the topic "Indice de qualité du signal":
1
Lers, Amnon, and Gan Susheng. Study of the regulatory mechanism involved in dark-induced Postharvest leaf senescence. United States Department of Agriculture, January 2009. http://dx.doi.org/10.32747/2009.7591734.bard.
Abstract:
Postharvest leaf senescence contributes to quality losses in flowers and leafy vegetables. The general goal of this research project was to investigate the regulatory mechanisms involved in dark-induced leaf senescence. The regulatory system involved in senescence induction and control is highly complex and possibly involves a network of senescence promoting pathways responsible for activation of the senescence-associated genes. Pathways involving different internal signals and environmental factors may have distinctive importance in different leaf senescence systems. Darkness is known to have a role in enhancement of postharvest leaf senescence and for getting an insight into its regulatory mechanism/s we have applied molecular genetics and functional genomics approaches. The original objectives were: 1. Identification of dark-induced SAGs in Arabidopsis using enhancer/promoter trap lines and microarray approaches; 2. Molecular and functional characterization of the identified genes by analyzing their expression and examining the phenotypes in related knockout mutant plants; 3. Initial studies of promoter sequences for selected early dark-induced SAGs. Since genomic studies of senescence, with emphasis on dark-induced senescence, were early-on published which included information on potential regulatory genes we decided to use this new information. This is instead of using the uncharacterized enhancer/promoter trap lines as originally planned. We have also focused on specific relevant genes identified in the two laboratories. Based on the available genomic analyses of leaf senescence 10 candidate genes hypothesized to have a regulatory role in dark-induced senescence were subjected to both expression as well as functional analyses. For most of these genes senescence-specific regulation was confirmed, however, functional analyses using knock-out mutants indicated no consequence to senescence progression. The transcription factor WARK75 was found to be specifically expressed during natural and dark-induced leaf senescence. Functional analysis demonstrated that in detached leaves senescence under darkness was significantly delayed while no phenotypic consequences could be observed on growth and development, including no effect on natural leaf senescence,. Thus, WARKY75 is suggested to have a role in dark-induced senescence, but not in natural senescence. Another regulatory gene identified to have a role in senescence is MKK9 encoding for a Mitogen-Activated Protein Kinase Kinase 9 which is upregulated during senescence in harvested leaves as well as in naturally senescing leaves. MKK9 can specifically phosphorylate another kinase, MPK6. Both knockouts of MKK9 and MPK6 displayed a significantly senescence delay in harvested leaves and possibly function as a phosphorelay that regulates senescence. To our knowledge, this is the first report that clearly demonstrates the involvement of a MAP kinase pathway in senescence. This research not only revealed a new signal transduction pathway, but more important provided significant insights into the regulatory mechanisms underlying senescence in harvested leaves. In an additional line of research we have employed the promoter of the senescence-induced BFN1 gene as a handle for identifying components of the regulatory mechanism. This gene was shown to be activated during darkinduced senescence of detached leaves, as well as natural senescence. This was shown by following protein accumulation and promoter activity which demonstrated that this promoter is activated during dark-induced senescence. Analysis of the promoter established that, at least some of the regulatory sequences reside in an 80 bps long fragment of the promoter. Overall, progress was made in identification of components with a role in dark-induced senescence in this project. Further studies should be done in order to better understand the function of these components and develop approaches for modulating the progress of senescence in crop plants for the benefit of agriculture.
2
Philosoph-Hadas, Sonia, Peter Kaufman, Shimon Meir, and Abraham Halevy. Signal Transduction Pathway of Hormonal Action in Control and Regulation of the Gravitropic Response of Cut Flowering Stems during Storage and Transport. United States Department of Agriculture, October 1999. http://dx.doi.org/10.32747/1999.7695838.bard.
Abstract:
Original objectives: The basic goal of the present project was to increase our understanding of the cellular mechanisms operating during the gravitropic response of cut flowers, for solving their bending problem without affecting flower quality. Thus, several elements operating at the 3 levels o the gravity-induced signal transduction pathway, were proposed to be examined in snapdragon stems according to the following research goals: 1) Signaling: characterize the signal transduction pathway leading to the gravitropic response, regarding the involvement of [Ca2+]cyt as a mediator of IAA movement and sensitivity to auxin. 2) Transduction by plant hormones: a) Examine the involvement of auxin in the gravitropic response of flower stems with regard to: possible participation of auxin binding protein (ABP), auxin redistribution, auxin mechanism of action (activation of H+-ATPase) mediation by changes in [Ca2+]cyt and possible regulation of auxin-induced Ca2+ action b: calmodulin-activated or Ca2+-activated protein kinases (PK). b) Examine the involvement of ethylene in the gravitropic response of flower stems with regard to auxin-induced ethylene production and sensitivity of the tissue to ethylene. 3) Response: examine the effect of gravistimulation on invertase (associated with growth and elongation) activity and invertase gene expression. 4) Commercial practice: develop practical and simple treatments to prevent bending of cut flowers grown for export. Revisions: 1) Model systems: in addition to snapdragon (Antirrhinum majus L.), 3 other model shoe systems, consisting of oat (Avena sativa) pulvini, Ornithogalun 'Nova' cut flowers and Arabidopsis thaliana inflorescence, were targeted to confirm a more general mechanism for shoot gravitropism. 2 Research topics: the involvement of ABP, auxin action, PK and invertase in the gravitropic response of snapdragon stems could not be demonstrated. Alternatively, the involvement in the gravity signaling cascade of several other physiological mediators apart of [Ca2+]cyt such as: IP3, protein phosphorylation and actin cytoskeleton, was shown. Additional topics introduced: starch statolith reorientation, differential expression of early auxin responsive genes, and differential shoot growth. Background to the topic: The gravitropic bending response of flowering shoots occurring upon their horizontal placement during shipment exhibits a major horticultural problem. In spite of extensive studies in various aboveground organs, the gravitropic response was hardly investigated in flowering shoots. Being a complex multistep process that requires the participation of various cellular components acting in succession or in parallel, analysis of the negative gravitropic response of shoot includes investigation of signal transduction elements and various regulatory physiological mediators. Major achievements: 1) A correlative role for starch statoliths as gravireceptors in flowering shoot was initially established. 2) Differentially phosphorylated proteins and IP3 levels across the oat shoe pulvini, as well as a differential appearance of 2 early auxin-responsive genes in snapdragon stems were all detected within 5-30 minutes following gravistimulation. 3) Unlike in roots, involvement of actin cytoskeleton in early events of the gravitropic response of snapdragon shoots was established. 4) An asymmetric IAA distribution, followed by an asymmetric ethylene production across snapdragon stems was found following gravistimulation. 5) The gravity-induced differential growth in shoots of snapdragon was derived from initial shrinkage of the upper stem side and a subsequent elongation o the lower stem side. 6) Shoot bending could be successfully inhibited by Ca2+ antagonists (that serve as a basis for practical treatments), kinase and phosphatase inhibitors and actin-cytoskeleton modulators. All these agents did not affect vertical growth. The essential characterization of these key events and their sequence led us to the conclusion that blocking gravity perception may be the most powerful means to inhibit bending without hampering shoot and flower growth after harvest. Implications, scientific and agriculture: The innovative results of this project have provided some new insight in the basic understanding of gravitropism in flower stalks, that partially filled the gap in our knowledge, and established useful means for its control. Additionally, our analysis has advanced the understanding of important and fundamental physiological processes involved, thereby leading to new ideas for agriculture. Gravitropism has an important impact on agriculture, particularly for controlling the bending of various important agricultural products with economic value. So far, no safe control of the undesired bending problem of flower stalks has been established. Our results show for the first time that shoot bending of cut flowers can be inhibited without adverse effects by controlling the gravity perception step with Ca2+ antagonists and cytoskeleton modulators. Such a practical benefit resulting from this project is of great economic value for the floriculture industry.
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Prusky, Dov, Lisa Vaillancourt, and Robert Fluhr. Host Ammonification by Postharvest Pathogens and its Contribution to Fungal Colonization and Symptom Development. United States Department of Agriculture, December 2006. http://dx.doi.org/10.32747/2006.7592640.bard.
Abstract:
Postharvest decay of fruits and vegetables caused by pathogenic and saprophytic fungi significantly impairs the quality and quantity of fresh produce brought to market. Consequently, there is considerable interest in identifying factors that determine the susceptibility of these commodities to pathogen infection. Insidious postharvest decays remain quiescent during fruit growth and harvest, but activate during the postharvest period. A key response to the physiological changes occurring during fruit ripening is the initiation of ammonium secretion by the pathogen. Ammonium ions at the infection site (ammonification) have subsequent effects on both the pathogen and the host. An accompanying alkalinization process resulting from ammonia accumulation contributes to pathogenicity, since some important fungal virulence factors, (such as pectate lyase in Colletotrichum sp.), are significantly expressed only under alkaline conditions. In this proposal, investigated the mechanisms by which ammonification and alkalinization of infected tissues by the pathogen affect the host’s defense response to fungal attack, and instead increase compatibility during postharvest pathogen-host interactions. Our hypotheses were:1) that host signals, including ripening-related changes, induce secretion of ammonia by the pathogen; 2) that ammonia accumulation, and the resultant environmental alkalinization regulate the expression of fungal virulence genes that are essential for postharvest rot development; 3) that ammonification enhanced fungal colonization, by “suppression of host responses”, including production of reactive oxygen species, activation of superoxide, and polyphenol oxidase production. Our objectives were: to analyze: 1) factor(s) which activate the production and secretion of ammonia by the fungus; 2) fungal gene(s) that play role(s) in the ammonification process; 3) the relationship between ammonification and the activation of host defense response(s) during pathogen colonization; and 4) analyze hostgene expression in alkalinized regions of fruits attacked by hemibiotrophic fungi.
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Armas, Elvira, Magaly Lavadenz, and Laurie Olsen. Falling Short on The Promise to English Learners: A Report on Year One LCAPs. Center for Equity for English Learners, 2015. http://dx.doi.org/10.15365/ceel.lcap2015.2.
Abstract:
California’s Local Control Funding Formula was signed into law in California in 2013 and allowed districts the flexibility to meet their student needs in locally appropriate manners. One year after its implementation, a panel of 26 reviewers, including educators, English Learner (EL) advocates, and legal services staff reviewed the Local Control and Accountability Plans (LCAPs) to understand how districts employ this flexibility to address the needs of ELs. The report uses the English Learner Research-Aligned LCAP Rubrics with 10 focus areas, and reviews sample LCAPs from 29 districts, including districts with the highest numbers/percentages of English Learners in the state, districts representative of California’s geographic Regions, and districts providing quality EL services. The review centers around four questions of the extent to which first-year LCAPs: (1) specify goals and identify outcomes for ELs, (2) identify action steps and allocate funds for increased or improved services for all types of ELs, (3) reflect research-based practices for achieving language proficiency and academic achievement for English Learners in their actions, programs and services, and (4) are designed and implemented with EL parent input as reflected in stakeholder engagement. The results indicate that overall, the LCAP is inadequate as part of the state’s public accountability system in ensuring equity and access for ELs. Six key findings were: (1) difficulty in discerning funding allocations related to EL services and programs; (2) inability to identify districts’ plans for increased services for ELs; (3) lack of explicitly specified services and programs aligned to EL needs; (4) weak approach or missing English Language Development (ELD) or implementation of ELD standards in most LCAPs; (5) weak/inconsistent representation of EL parent engagement; and (6) lack of EL student outcome measures. The authors also present detailed findings for each focus topic and offer district and state level recommendations.
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Lers, Amnon, and Pamela J. Green. Analysis of Small RNAs Associated with Plant Senescence. United States Department of Agriculture, March 2013. http://dx.doi.org/10.32747/2013.7593393.bard.
Abstract:
Senescence is an agriculturally significant process due to its negative impact to crop yield and postharvest quality. The genetic regulatory systems controlling senescence induction and progress respond to both developmental and environmental stress signals and involve numerous gene expression changes. Knowledge about the key molecular factors which control senescence is very limited. MicroRNAs (miRNAs) are a class of small RNAs which typically function by guiding cleavage of target messenger RNAs. They have been shown to play major roles in a variety of plant processes including development, responses to environmental stresses, and senescence. The long-term goal of this work is to elucidate roles of small RNAs associated with plant senescence. The hypothesis underlying this research is that miRNA-mediated regulation makes important contributions to the senescence process in plants. Specific, original research objectives included: 1) Profiling of small RNAs from senescing plants; 2) Data Analysis and public access via a user-friendly web interface; 3) Validation of senescence-associated miRNAs and target RNAs; 4) Development of transgenic plants for functional analysis of miRNAs in Arabidopsis. Major revisions made in the research compared to the original work plan included 1) Exclusion of the planned work with tomato as recommended by the BARD review panel; 2) Performing miRNA study also in senescing Arabidopsis siliques, in addition to senescing leaves. To identify senescenceregulation of miRNAs in Arabidopsis thaliana, eight small RNA libraries were constructed and sequenced at four different stages of development and senescence from both leaves and siliques, resulting in more than 200 million genome-matched sequences. Parallel Analysis of RNA Ends (PARE) libraries, which enable the large-scale examination of miRNA-guided cleavage products, were also constructed and sequenced, resulting in over 750 million genome-matched sequences. These massive datasets lead to the identification of new miRNAs, as well as new regulation of known miRNAs and their target genes during senescence, many of which have established roles in nutrient responsiveness and cell structural integrity. In keeping with remobilization of nutrients thought to occur during senescence, many miRNAs and targets had opposite expression pattern changes between leaf and silique tissues during the progression of senescence. Taken together, these findings highlight the integral role that miRNAs may play in the remobilization of resources and alteration of cellular structure that is known to occur in senescence. Experiments were initiated for functional analysis of specific senescence-associated miRNAs and respective target genes. Transgenic Arabidopsis plants were generated in which miR408, found in this study to be significantly induced in leaf senescence, was over-expressed either constitutively or under a senescence-specific promoter. These plants are currently being characterized for any altered phenotypes. In addition T-DNA knock out mutants for various target genes identified in this research are being analyzed. This work provides insights about specific miRNAs that contribute to leaf and silique senescence. The knowledge generated may suggest new strategies to monitor and alter the progression of senescence in crops for agricultural improvement.