La réduction des marges temporelles dans les circuits synchrones est une manière d'améliorer leur performance.En cas de vieillissement, de fluctuations de la tension d'alimentation ou de la température du milieu de mission, des réductions sévères des marges temporelles peuvent néanmoins avoir un impact négatif sur la fiabilité des circuits. La réduction des marges temporelles sans dégradation de la fiabilité peut être réalisée à l'aide des informations d'un contrôle en ligne de ces marges. Cette thèse porte sur l'étude du suivi en ligne des marges temporelles des circuits intégrés synchrones. La première contribution de ce travail consiste en une nouvelle solution shadow-scan bien adaptée au suivi en ligne des marges temporelles, permettant une mise en œuvre de bascules scan plus rapides et pouvant être gérées de façon transparente par les outils de conception du commerce. Une approche naturelle de mise en œuvre du suivi des marges temporelles est le déploiement de moniteurs sur tous les chemins critiques ou susceptibles de le devenir à cause du vieillissement ou des variations dues au processus de production.Dans des circuits très contraints en termes de temps de propagation, avec un grand nombre de chemins critiques, cette approche peut conduire à un surcoût en surface trop important pour un gain en performance limité. Afin de pouvoir réduire le nombre de moniteurs avec un impact limité sur la qualité du monitoring, la seconde contribution de ce travail est la proposition d'une nouvelle méthode d'évaluation de la qualité du monitoring d'un groupe de bascules.Cette méthode est basée sur l'estimation de la probabilité d'activation des moniteurs. Deux métriques sont proposées pour quantifier la qualité du suivi des marges temporelles. La première sert à estimer la couverture temporelle d'un groupe de bascules, alors que la deuxième permet d'évaluer la couverture spatiale.Enfin, en se basant sur ces deux métriques, la dernière contribution de ce travail est la démonstration du fait qu'il est possible avec un surcoût limité d'améliorer significativement la qualité du monitoring d'un circuit si les moniteurs sont adaptés aux cônes logiques qu'ils surveillent. / Slack-time reduction is a way to improve the performance of synchronous sequential circuits. In the presence of circuit wear-out, supply voltage fluctuations and temperature variations, aggressive slack-time reduction can be achieved based on adaptive voltage and frequency scaling with feedback from in-situ slack-time monitoring. The first contribution of this work consist of a new shadow-scan solution which facilitates the implementation of faster scan Flip-Flops (FFs), enables in-situ slack-time monitoring and can be transparently handled by commercial tools for automated scan stitching and automated test pattern generation. A natural approach is to place in-situ slack-time monitors close to all sequential elements with incoming timing-critical paths or susceptible to become timing-critical due to wear-out or manufacturing variability. In latency-constrained circuits with large ratios of timing-critical paths, this methodology may result in large area overheads and minor power improvements. The second contribution of this work is an evaluation methodology of the monitoring quality delivered by a set of FFs. This methodology estimates monitor activation probabilities based on which two evaluation metrics are provided. On one hand, the expected ratio of clock cycles with at least one monitor activated can be used to estimate the temporal coverage of the in-situ slack-time monitoring scheme. On the other hand, the expected number of activated monitors per clock cycle can be used to evaluate the spatial coverage of the monitoring scheme. Finally, based on these metrics, it is shown that the monitoring quality can be significantly improved if the size of the detection window of each in-situ slack-time monitor is correlated to the slack-time of the monitored timing-critical paths.

Substation apparatus failure plays a major role in reliability of power delivery systems. Traditionally, most utilities perform regular maintenance in order to prevent equipment breakdown. Condition-based maintenance strategy monitors the condition of the equipment by measuring and analyzing key parameters and recommends optimum maintenance actions. Equipment such as transformers and standby batteries which are valuable and critical assets in substations has attracted increased attentions in recently years. An automated monitoring and diagnosis tool for power transformers based on dissolved gas analysis, ANNEPS v4.0, was developed. The new tool extended the existing expert system and artificial neural network diagnostic engine with automated data acquisition, display, archiving, and alarm notification functions. This thesis also studied substation batteries types and failure mode and surveyed the market of current on-line battery monitors. A practical battery monitoring system architecture was proposed. Analysis rules of measured parameters were developed. The above study and results can provide basics for further designing of a simple battery monitoring system in industry applications. / Master of Science

Neste trabalho estudou-se o processo de polimerização de estireno em miniemulsão, através do monitoramento in-line da conversão do monômero e do tamanho das partículas geradas durante o processo de polimerização, através das técnicas espectroscópicas de Infravermelho Próximo (Near Infra Red - NIR) e Raman. As medições off-line de conversão foram feitas através de gravimetria e do tamanho das partículas através de Espalhamento Dinâmico de Luz (Dynamic Light Scattering - DLS). Também foi objeto deste estudo a modelagem matemática do process de polimerização em miniemulsão, assim como sua simulação utilizando o programa Matlab. A metodologia adotada para a obtenção dos resultados envolveu o trabalho experimental de monitoramento da síntese de poliestireno em miniemulsão utilizando iniciador hidrossolúvel (persulfato de potássio), tensoativo (lauril sulfato de sódio) e co-estabilizantes (hexadecano e poliestireno) e equipamento rotor-estator, Ultra Turrax T25, para obtenção da miniemulsão. O modelo matemático envolveu a determinação de equações fenomenológicas representativas do sistema em questão, prevendo as possíveis variações na cinética e fenômenos físico-químicos, decorrentes de variações na formulação prevendo inclusive os mecanismos de nucleação existentes em função da concentração de tensoativo utilizado. Como resultado, este trabalho validou as metodologias avaliadas para monitoramento da conversão e diâmetro das partículas poliméricas e também, ao comparar as metodologias avaliadas, identificou a espectroscopia NIR como metodologia preferencial por não exigir preparação da amostra, fornecer respostas em tempo real, sem defasagem de tempo e também por permitir coletar espectros com pequenos intervalos de tempo, garante melhor precisão e evita a perda de informações do processo. / In this work, is the development of a detailed study of the miniemulsion polymerization process monitoring monomer conversion and particle size along process. Near Infrared Spectroscopy (Near Infra Red - NIR) and Raman Spectroscopy were used to conversion and diameter determination. Gravimetric analyses were used to conversion determination. Dynamic Light Scattering (Dynamic Light Scattering - DLS) to particle size determination. It was also object of this study the Mathematical Modeling of Miniemulsion Polymerization Reaction Kinetic, as well as it simulation using Matlab software. The methodology used to obtain the results involved experimental work to synthesize and monitor miniemulsion polystyrene using water-soluble initiator (potassium persulfate), stabilizer (sodium lauryl sulfate) and co-stabilizers (hexadecane and polystyrene) and rotor-stator equipment Ultra Turrax T25 for miniemulsion obtaining. The mathematical model involved the determination of representative phenomenological equations this system, anticipating the possible variations in kinetics and physical-chemical phenomena, resulting from formulation variations mainly by verifying the surfactant concentration [S] to determine the existing nucleation mechanism when compared with the same surfactant critical micelle concentration [CMC]. The provided mechanisms are: micellar nucleation to [S] [CMC], droplets nucleation and homogeneous nucleation to [S] < [CMC]. As a result, this study validated the proposed methods for monitoring conversion and polymer particles diameter and also compare the evaluated methodologies, identifying NIR spectroscopy as a differential method among others for not to require sample preparation, supply answers in real time, no time delay and also to perform in shorter intervals, preventing the loss of process information.

Neste trabalho estudou-se o processo de polimerização de estireno em miniemulsão, através do monitoramento in-line da conversão do monômero e do tamanho das partículas geradas durante o processo de polimerização, através das técnicas espectroscópicas de Infravermelho Próximo (Near Infra Red - NIR) e Raman. As medições off-line de conversão foram feitas através de gravimetria e do tamanho das partículas através de Espalhamento Dinâmico de Luz (Dynamic Light Scattering - DLS). Também foi objeto deste estudo a modelagem matemática do process de polimerização em miniemulsão, assim como sua simulação utilizando o programa Matlab. A metodologia adotada para a obtenção dos resultados envolveu o trabalho experimental de monitoramento da síntese de poliestireno em miniemulsão utilizando iniciador hidrossolúvel (persulfato de potássio), tensoativo (lauril sulfato de sódio) e co-estabilizantes (hexadecano e poliestireno) e equipamento rotor-estator, Ultra Turrax T25, para obtenção da miniemulsão. O modelo matemático envolveu a determinação de equações fenomenológicas representativas do sistema em questão, prevendo as possíveis variações na cinética e fenômenos físico-químicos, decorrentes de variações na formulação prevendo inclusive os mecanismos de nucleação existentes em função da concentração de tensoativo utilizado. Como resultado, este trabalho validou as metodologias avaliadas para monitoramento da conversão e diâmetro das partículas poliméricas e também, ao comparar as metodologias avaliadas, identificou a espectroscopia NIR como metodologia preferencial por não exigir preparação da amostra, fornecer respostas em tempo real, sem defasagem de tempo e também por permitir coletar espectros com pequenos intervalos de tempo, garante melhor precisão e evita a perda de informações do processo. / In this work, is the development of a detailed study of the miniemulsion polymerization process monitoring monomer conversion and particle size along process. Near Infrared Spectroscopy (Near Infra Red - NIR) and Raman Spectroscopy were used to conversion and diameter determination. Gravimetric analyses were used to conversion determination. Dynamic Light Scattering (Dynamic Light Scattering - DLS) to particle size determination. It was also object of this study the Mathematical Modeling of Miniemulsion Polymerization Reaction Kinetic, as well as it simulation using Matlab software. The methodology used to obtain the results involved experimental work to synthesize and monitor miniemulsion polystyrene using water-soluble initiator (potassium persulfate), stabilizer (sodium lauryl sulfate) and co-stabilizers (hexadecane and polystyrene) and rotor-stator equipment Ultra Turrax T25 for miniemulsion obtaining. The mathematical model involved the determination of representative phenomenological equations this system, anticipating the possible variations in kinetics and physical-chemical phenomena, resulting from formulation variations mainly by verifying the surfactant concentration [S] to determine the existing nucleation mechanism when compared with the same surfactant critical micelle concentration [CMC]. The provided mechanisms are: micellar nucleation to [S] [CMC], droplets nucleation and homogeneous nucleation to [S] < [CMC]. As a result, this study validated the proposed methods for monitoring conversion and polymer particles diameter and also compare the evaluated methodologies, identifying NIR spectroscopy as a differential method among others for not to require sample preparation, supply answers in real time, no time delay and also to perform in shorter intervals, preventing the loss of process information.

Thesis (MScEng (Process Engineering))--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: Hydrocyclones are separation devices that are widely used throughout the chemical engineering and mineral processing industries. Although simple in design, the intricate flow structure of the device complicates control. As an alternative to conventional empirical and theoretical modelling, process state monitoring methods have recently been employed as a means to control hydrocyclones. The purpose of process state monitoring methods is to distinguish between the desired operating state with favourable separation, the transition state, and the troublesome operating state of dense flow separation. In comparison to previously employed monitoring techniques, image analysis of the underflow is regarded as a promising approach. Preliminary studies have indicated that the technique complies with hydrocyclone monitoring requirements: sensitivity, non-invasiveness, sampling times less than one second, robustness and low cost. The primary objective of this study was therefore defined as investigating the feasibility of image analysis of hydrocyclone underflow as a monitoring technique. Data collection entailed the recording of hydrocyclone underflow for different operating states. Six case studies were performed in total: Gold, Ilmenite, Platreef, Merensky 1, Merensky 2 and Merensky 3 (with the case study names indicating the different ore types used). An image analysis technique, consisting of feature extraction through motion detection, as well as various noise reduction methods, was consequently developed and applied to the video data. Classification of the various operating states was attempted by performing modelling by one-class support vector machines (SVM). Results indicated that the developed image analysis technique effectively addresses background noise, random noise and system vibration through image enhancement and a motion threshold. Extremely low contrast differences and foreground noise did, however, prove problematic in Ilmenite and Merensky 1 case studies respectively. For the remaining case studies, it was found that the various operating states were identified with high accuracy through one-class SVM classification. This is particularly true for the identification of the troublesome dense flow separation for which extremely low missing alarm rates were obtained (0 % in most cases). In terms of practicality, the technique proved to be sensitive, non-intrusive and economical. The sampling time of 30 frames per second and estimated processing to video time ratio of 1:1, is furthermore satisfactory. Ultimately, the results indicate that the image analysis of hydrocyclone underflow is a viable monitoring technique. The robustness of the technique might further be improved by use of backlighting and an air-knife. It is also recommended that future work should focus on testing the monitoring technique on an industrial hydrocyclone setup. / AFRIKAANSE OPSOMMING: Hidrosiklone is skeidingsapparate wat algemeen gebruik word in chemiese ingenieurswese en mineraalprosesserings industrieë. Alhoewel die apparaat ‘n eenvoudige ontwerp het, bemoeilik die komplekse interne vloeistruktuur die beheer daarvan. Prosestoestandmoniteringsmetodes is vir hidrosikloonbeheer toegepas as alternatief vir konvensionele empiriese en teoretiese modellering. Die doel van prosestoestandmoniteringsmetodes is om te onderskei tussen die gewenste bedryfstoestand met gunstige skeiding, die oorgangstoestand, en die moeilike bedryfstoestand van digtevloeiskeiding. In vergelyking met vorige toegepaste moniteringstegnieke, word beeldverwerking van die ondervloei beskou as ‘n belowende tegniek. Voorlopige studies het aangedui dat die tegniek voldoen aan die hidrosikloonmoniteringvereistes: sensitiwiteit, nie-indringendheid, monsternemingstydperke laer as een sekonde, robuustheid en lae koste. Die primêre doelwit van hierdie studie is daarom gedefineer as die ondersoek van die doenlikheid van beeldverwerking van hidrosikloon ondervloei as ‘n moniteringstegniek. Die data versameling het die afneem van hidrosikloon ondervloei vir verskillende bedryfstoestande behels. Ses gevallestudies is in totaal uitgevoer: Goud, Ilmeniet, Platreef, Merensky 1, Merensky 2 en Merensky 3 (die gevallestudie name dui die verskillende erts tipes wat gebruik is aan). ‘n Beeldverwerkingstegniek, wat bestaan uit kenmerkekstraksie deur bewegingsopsporing, asook verskeie geruisverlagingsmetodes, is gevolglik ontwikkel en toegepas op die video data. Klassifikasie van die verskeie bedryfstoestande is beproef deur modellering met enkelklassteunvektormasjiene. Resultate het aangedui dat die ontwikkelde beeldverwerkingstegniek agtergrond geruis, onreëlmatige geruis en sisteem vibrasie suksesvol aanspreek deur beeldversterking en ‘n bewegingslimiet. Beduidende lae kontrasverskille en voorgrond geruis blyk wel problematies in die Ilmeniet en Merensky 1 gevallestudies onderskeidelik. Vir die orige gevallestudies is gevind dat die verskillinde bedryfstoestande met hoë akkuraatheid geïdentifiseer is deur enkelklassteunvektormasjiene klassifisering. Dit is veral waar vir die identifisering van die moeilike digtevloeiskeiding waarvoor beduidende lae vermiste-alarmmaatstawwe behaal is (0 % in die meeste gevalle). Aangaande die praktiese aspekte, blyk die tegniek sensitief, nie-indringend en ekonomies. Die monsternemingstydperk van 30 raampies per sekonde en die beraamde prosesserings- tot videotyd verhouding van 1:1, is ook voldoende. Ten slotte dui die resultate daarop dat die beeldverwerking van hidrosikloon ondervloei ‘n uitvoerbare moniteringstegniek is. Die robuustheid van die tegniek sou verder verbeter kon word deur gebruik te maak van agtergrondverligting en ‘n lugspuit. Dit word ook aanbeveel dat toekomstige werk op die toetsing van die moniteringstegniek op ‘n industriële hidrosikloon toestel moet fokus.

Development of an automated method for classifying digital images using a combination of image quality modification and Bayesian classification is the subject of this thesis. The specific example is classification of images obtained by monitoring molten plastic in an extruder. These images were to be classified into two groups: the “with particle” (WP) group which showed contaminant particles and the “without particle” (WO) group which did not. Previous work effected the classification using only an adaptive Bayesian model. This work combines adaptive image quality modification with the adaptive Bayesian model. The first objective was to develop an off-line automated method for determining how to modify each individual raw image to obtain the quality required for improved classification results. This was done in a very novel way by defining image quality in terms of probability using a Bayesian classification model. The Nelder Mead Simplex method was then used to optimize the quality. The result was a “Reference Image Database” which was used as a basis for accomplishing the second objective. The second objective was to develop an in-line method for modifying the quality of new images to improve classification over that which could be obtained previously. Case Based Reasoning used the Reference Image Database to locate reference images similar to each new image. The database supplied instructions on how to modify the new image to obtain a better quality image. Experimental verification of the method used a variety of images from the extruder monitor including images purposefully produced to be of wide diversity. Image quality modification was made adaptive by adding new images to the Reference Image Database. When combined with adaptive classification previously employed, error rates decreased from about 10% to less than 1% for most images. For one unusually difficult set of images that exhibited very low local contrast of particles in the image against their background it was necessary to split the Reference Image Database into two parts on the basis of a critical value for local contrast. The end result of this work is a very powerful, flexible and general method for improving classification of digital images that utilizes both image quality modification and classification modeling.

Development of an automated method for classifying digital images using a combination of image quality modification and Bayesian classification is the subject of this thesis. The specific example is classification of images obtained by monitoring molten plastic in an extruder. These images were to be classified into two groups: the “with particle” (WP) group which showed contaminant particles and the “without particle” (WO) group which did not. Previous work effected the classification using only an adaptive Bayesian model. This work combines adaptive image quality modification with the adaptive Bayesian model. The first objective was to develop an off-line automated method for determining how to modify each individual raw image to obtain the quality required for improved classification results. This was done in a very novel way by defining image quality in terms of probability using a Bayesian classification model. The Nelder Mead Simplex method was then used to optimize the quality. The result was a “Reference Image Database” which was used as a basis for accomplishing the second objective. The second objective was to develop an in-line method for modifying the quality of new images to improve classification over that which could be obtained previously. Case Based Reasoning used the Reference Image Database to locate reference images similar to each new image. The database supplied instructions on how to modify the new image to obtain a better quality image. Experimental verification of the method used a variety of images from the extruder monitor including images purposefully produced to be of wide diversity. Image quality modification was made adaptive by adding new images to the Reference Image Database. When combined with adaptive classification previously employed, error rates decreased from about 10% to less than 1% for most images. For one unusually difficult set of images that exhibited very low local contrast of particles in the image against their background it was necessary to split the Reference Image Database into two parts on the basis of a critical value for local contrast. The end result of this work is a very powerful, flexible and general method for improving classification of digital images that utilizes both image quality modification and classification modeling.

Orientador: José Antonio Siqueira Dias / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-25T04:25:15Z (GMT). No. of bitstreams: 1 Soares_PaulodaSilva_D.pdf: 5062177 bytes, checksum: b08acd7cd74b46ed7ade778b2cbed7cf (MD5) Previous issue date: 2014 / Resumo: Neste trabalho é apresentado o desenvolvimento de um sistema de baixo custo para monitoração e acompanhamento de equipamentos industriais com vistas à manutenção preditiva. O sistema desenvolvido monitora a vibração do elemento em estudo, e faz o registro da mesma comparando-se a um padrão de vibração considerado nominal, ou seja, uma condição de operação satisfatória da máquina. Quando uma variação na vibração do dispositivo monitorado é identificada, há de se observar seu comportamento, não só de amplitude mas também no espectro de frequência, pois geralmente a incidência de falhas ou anomalias apresentam vibrações em frequências diferentes da nominal de trabalho de um dispositivo. A Transformada de Fourier do sinal e os registros de leituras frequentes nos permitem um acompanhamento contínuo do equipamento monitorado. Adicionalmente ao acompanhamento da vibração mecânica, faz-se o monitoramento da corrente elétrica do motor de acionamento do elemento para observância de eventual sobrecarga, desequilíbrio das fases e análise do espectro de frequência do sinal elétrico de corrente, que nos permite avaliar as alterações na alimentação do mesmo, indicando alguma anomalia de natureza elétrica ao motor em estudo. Por fim ainda monitora-se a temperatura dos elementos em estudo, pois a vida útil destes depende das temperaturas a que são submetidos em regime de operação que têm impacto direto em isolamentos de bobinas e lubrificantes das partes mecânicas. Este sistema permite uma avaliação de uma máquina, sem intervenção humana para as medições de vibração e elétricas, aliado ao histórico levantado, torna-se uma ferramenta poderosa para a implementação de um programa de manutenção preditiva / Abstract: This work aims to develop a low-cost system for monitoring and tracking of industrial equipment with a view to predictive maintenance. It presents a system that monitors vibration of the recording studied element comparing the same to a vibration pattern considered nominal. When it detects a change in the vibration of the device is to observe their behavior, not only amplitude but in the frequency spectrum, usually because the incidence of faults or anomalies exhibit vibrations at different frequencies of nominal working of a device. The Fourier transform of the signal and records of frequent readings allow to close monitoring of the element under study. In addition to monitoring the mechanical vibration, it is monitoring the electrical current of the motor drive element for compliance with any overload, phase imbalance and even the analysis of spectro signal frequency electric current, which allows us to evaluate changes feeding the same, indicating an abnormality of the electric motor in nature study. Finally even monitor the temperature of the elements under study, because the life of these depends on the temperatures to which they are subjected in operation regime that have direct impact on coil insulation and lubricants of the mechanical parts. This system permits an automatic evaluation of the condition of a machine, without human intervention for measurement of vibration and electrical therein, together with the historical raised, becomes a powerful tool for industry implementation of a predictive maintenance program / Doutorado / Eletrônica, Microeletrônica e Optoeletrônica / Doutor em Engenharia Elétrica

Les arômes fermentaires (alcools supérieurs, esters) jouent un rôle important dans le profil organoleptique des vins jeunes. Leur production dépend à la fois de la souche de levure utilisée et des paramètres environnementaux. Pour comprendre le rôle de trois facteurs clés (température, azote, lipides) sur la production des arômes fermentaires, nous avons réalisé une étude comparative entre une souche évoluée aromatique Affinity™ ECA5 et sa souche ancestrale Lalvin EC1118®. Dans un premier temps, les effets combinés des trois paramètres environnementaux ont été étudiés grâce à un plan expérimental de Box-Behnken. L'azote est le facteur ayant la plus grande influence sur la majorité des composés volatils; cependant son effet est différent selon la molécule ciblée et les interactions entre facteurs sont importantes. Par ailleurs, si les deux souches répondent dans le même sens aux changements de conditions de fermentation, les intensités de réponse sont très différentes. Pour avancer dans la compréhension des mécanismes mis en jeu et en particulier dans l'analyse de l'interaction azote / lipides, nous avons combiné des études de suivi cinétique précis de la production des arômes fermentaires et une approche transcriptomique. Ces études ont révélé des différences entre les deux souches dans la chronologie de formation des arômes, suggérant des modifications dans la régulation de leur synthèse. En particulier, le rendement de conversion entre alcools supérieurs et esters d'acétate est largement supérieur chez Affinity™ ECA5, mais diminue fortement après addition de phytostérols, en lien avec une répression des gènes de la voie de synthèse des stérols. Ces résultats montrent une gestion différente des lipides par la souche évoluée et suggèrent qu'une plus grande disponibilité en acétyl-CoA pourrait être à l'origine des propriétés aromatiques de cette souche. Enfin, une approche quantitative basée sur la filiation isotopique de sources d'azote marquées 13C a été réalisée. Cette étude confirme le rôle clé de l'acétyl-CoA dans une gestion différentielle du pool d'α-cetoacides responsable de la surproduction des alcools supérieurs chez Affinity™ ECA5. Globalement, ce travail a permis d'identifier les paramètres les plus efficaces pour orienter le métabolisme fermentaire vers la production d'arômes ainsi que certains mécanismes impliqués. Il a également permis de mieux caractériser le métabolisme de la souche évoluée Affinity™ ECA5. Les connaissances acquises constituent une avancée importante pour une amélioration de la gestion de la nutrition en fermentation œnologique. / Fermentative aromas (higher alcohols, esters) have a major role in the organoleptic profile of young wines. Their production depends on both the used yeast strain and environmental parameters. To better understand the role of three key factors (temperature, nitrogen, lipids) on the synthesis of fermentative aromas, we compared an aromatic evolved strain Affinity™ ECA5 and its parent strain Lalvin EC1118®. First, the combined effects of these three parameters were investigated through an experimental Box-Behnken design. Nitrogen greatly impacted the majority of the volatile compounds but differently depending on the targeted molecule and in interaction with the other factors. Overall, both strains showed similar responses to changes in fermentation conditions but with different intensities. To improve the understanding of the involved mechanism, particularly in the study of nitrogen / lipids interaction, several approaches were combined. A precise on-line monitoring of the production kinetics of fermentative aromas coupled with transcriptomic analysis revealed differences between the two strains in the chronology of aroma synthesis, suggesting changes in the regulation of their production. In particular, the conversion yield between a higher alcohol and its acetate ester differed greatly between the two strains. We have shown that this difference was due to a different lipid management by the strain Affinity™ ECA5. Finally, a quantitative approach based on the isotopic filiation of 13C labelled nitrogen sources was performed. This study confirms the key role of acetyl-CoA in a differential management of α-ketoacid pool responsible for the overproduction of higher alcohols by Affinity ™ ECA5.Overall, this project identified the most effective parameters to guide the fermentative metabolism toward the production of aromas and to better understand mechanisms involved. It also better characterized the metabolism of the evolved strain Affinity™ ECA5. These results are crucial to improve the management of nutrition in wine fermentation.

This thesis deals with vibration diagnostics and on-line monitoring systems of several producers. Furthermore, this thesis contains a description and evaluation of measuring the vibrations of the machine tool spindle when machining test samples with different cutting conditions and evaluating the surface quality of test samples.