No description available.

Includes an exploration of working memory models from a musical standpoint. / A musical key can only be retained in memory for approximately 20 seconds. However, other factors may be influencing the strength of this retention. The current study tests the influence of time and number of events (chords) in an intervening key on the deterioration in memory of a nonadjacent key. Stimuli first established a major key using traditional harmonic rules, then modulated to an intervening key that was either 6 or 9 seconds in duration and formed from either 4 or 6 chords. Stimuli then returned to the original key in a probe cadence. Participants were asked to rate this cadence in terms of its sense of closure. It was revealed that there is a significant negative effect of time on the probe cadence though no effect of number of events was found. This suggests that spending more time in an intervening key, and not the number of intervening chords, diminishes the memory of the original key. However, it is unclear from this study where in memory the nonadjacent key relationship is processed. Relevant literature is examined to form a working hypothesis with the goal of strengthening future studies with a capable foundation in memory research and theories. / Thesis / Master of Science (MSc) / We have a very short memory span for musical keys. Humans can only remember a key for approximately 20 seconds after it’s changed. However, it is unclear whether it is time spent away from the key that makes us forget or if it is the number of chords we heard in a second, interrupting key. The current study tests this distinction using nonadjacent key relationships—in which a key is established, a different key interrupts for a random amount of time and number of chords before returning to the original key for two target chords. Results confirmed previous findings as there was a significant effect of time on memory. However, there was no effect of number of chords, suggesting that it is the length of time spent away from a key, not number of chords that has an effect on memory.

Au laboratoire comme sur le terrain, le choix de la cadence lors de l’exercice de pédalage est un élément important dans la réalisation d’un exercice. De nombreux travaux ont porté sur l’effet de la cadence de pédalage sur différents aspects tels que la performance, les paramètres cardiorespiratoires, la participation du métabolisme « anaérobie » et le recrutement musculaire. Cependant, très peu de travaux ont étudié l’effet de la cadence de pédalage sur la disponibilité et l’utilisation d’O2 au niveau musculaire et cérébral. L’objectif principal de cette thèse était de comprendre les effets de la cadence de pédalage sur la disponibilité en O2 ainsi que l’utilisation d’O2 au niveau musculaire et cérébral. Le but de nos trois plans expérimentaux était d’étudier d’une part l’effet de la cadence de pédalage sur l’hétérogénéité de la déoxygénation musculaire lors de l’exercice modéré et d’autre part l’effet de la cadence sur l’oxygénation musculaire et cérébrale et sur la performance lors de l’exercice intense chez des sujets non entraînés ainsi que chez des sujets entraînés à l’endurance.Ce travail nous a permis de montrer que, lors de l’exercice d’intensité modérée, V ̇O2 de l’organisme entier et l’hétérogénéité de la déoxygénation musculaire étaient plus élevées à cadence élevée qu’à cadence faible, bien que la déoxygénation n’était pas modifiée par la cadence de pédalage chez les sujets non entraînés à l’endurance. D’autre part, lors de l’exercice intense mené jusqu’à l’épuisement, la performance était améliorée à 40 rpm par rapport à 100 rpm chez les sujets non entraînés tandis qu’aucune différence significative n’était observée entre les deux cadences chez les triathlètes. De plus, l’extraction d’O2 au niveau du vastus lateralis était dépendante de la cadence de pédalage chez les sujets non entraînés mais ne l’était pas chez les sujets entraînés à l’endurance. Enfin, nous avons observé un effet de la cadence de pédalage sur l’oxygénation cérébrale et en particulier une possible élévation de la disponibilité en O2 au niveau cérébral à faible cadence de pédalage chez les deux populations. Pour conclure, ce travail nous a permis de mettre en évidence des différences liées à l’aptitude aérobie des sujets et à l’intensité de l’exercice dans les réponses de l’oxygénation cérébrale et musculaire et de la performance lors d’exercices effectués à différentes cadences. / Choosing the pedalling cadence during the cycling exercise, in the laboratory as well as on the field, is a crucial element in fulfilling an exercise. Many studies have examined the effect of pedal cadence on various aspects such as performance, cardiorespiratory parameters, the participation of the “anaerobic” metabolism and muscle recruitment. However, few studies have investigated the effect of pedal cadence on the O2 availability and its utilization in the muscle as well as in the brain. This is why the main objective of this thesis was to understand this subject which is underdeveloped. The aim of our three experimental procedures was on one hand to study the effect of pedal cadence on the heterogeneity of the muscle’s deoxygenation during moderate exercise. On the other hand, to study the effects of pedal cadence on muscle and cerebral oxygenation and also on the performance during heavy exercise in untrained subjects, as well as in endurance-trained subjects.This work allows us to show that at moderate-intensity exercise, whole body V ̇O2 and the heterogeneity of muscle deoxygenation were higher at high cadence than at a lower one, even if the deoxygenation was not altered by the pedalling cadence in non-endurance-trained subjects. On the other hand, during intense exercise performed until exhaustion, the performance improved at 40 rpm than at 100 rpm in untrained subjects, while no significant difference was observed between the two cadences among triathletes. In addition, the O2 extraction in the vastus lateralis depended on the pedal cadence in untrained subjects and the opposite in endurance-trained subjects. Finally, we observed an effect of pedal cadence on cerebral oxygenation and in particular a possible rise in the availability of O2 in the brain on a lower cadence in both population levels. In conclusion, this work has allowed us to highlight the differences in the aerobic fitness of the subjects and in the intensity of the exercise in brain and muscle oxygenation responses and performance during exercises performed at different cadences.

Thesis describes analog filters topologies with capability of tuning of the main parameters and the MOSFET-C and switched-capacitor filters are described. With focus to linearity and maximal tuning range optimal topology have been chosen. In work the issue of analog switch design is described and is solved. Design of switched-capacitor low-pass Sallen-key filter in Cadence software was made and simulation results are presented.

Les maladies cardiaques sont une cause majeure de mortalité dans le monde (la première cause en Amérique du nord [192]), et la prise en charge de ses maladies entraîne des coûts élevés pour la société. La prévalence de l’insuffisance cardiaque augmente fortement avec l’âge, et, avec une population vieillissante, elle va demeurer une préoccupation croissante dans le futur, non seulement pour les pays industrialisés mais aussi pour ceux en développement. Ainsi il est important d’avoir une bonne compréhension de son mécanisme pour obtenir des diagnostics précoces et un meilleur prognostic pour les patients. Parmi les différentes formes d’insuffisance cardiaque, on trouve la dysfonction diastolique qui se traduit par une déficience du remplissage du ventricule. Pour une meilleure compréhension de ce mécanisme, de nombreuses études se sont intéressées au mouvement du sang dans le ventricule. On sait notamment qu’au début de la diastole le flux entrant prend la forme d’un anneau vortical (ou vortex ring). La formation d’un vortex ring par le flux sanguin après le passage d’une valve a été décrite pour la première fois en 1513 par Léonard de Vinci (Fig. 0.1). En effet après avoir moulé l’aorte dans du verre et ajouter des graines pour observer le flux se déplaçant dans son fantôme, il a décrit l’apparition du vortex au passage de la valve aortique. Ces travaux ont pu être confirmés 500 ans plus tard avec l’apparition de l’IRM [66]. Dans le ventricule, le même phénomène se produit après la valve mitrale, c’est ce qu’on appelle le vortex diastolique. Or, le mouvement d’un fluide (ici le sang) est directement relié a son environnement : la forme du ventricule, la forme de la valve, la rigidité des parois... L’intérêt est donc grandissant pour étudier de manière plus approfondie ce vortex diastolique qui pourrait apporter de précieuses informations sur la fonction diastolique. Les modalités d’imagerie permettant de le visualiser sont l’IRM et l’échographie. Cette thèse présente l’ensemble des travaux effectués pour permettre une meilleure caractérisation du vortex diastolique dans le ventricule gauche par imagerie ultrasonore Doppler. Pour suivre la dynamique de ce vortex dans le temps, il est important d’obtenir une bonne résolution temporelle. En effet, la diastole ventriculaire dure en moyenne 0.5 s pour un coeur humain au repos, une cadence élevée est donc essentielle pour suivre les différentes étapes de la diastole. La qualité des signaux Doppler est également primordiale pour obtenir une bonne estimation des vitesses du flux sanguin dans le ventricule. Pour étudier ce vortex, nous nous sommes intéressés à la mesure de sa vorticité en son centre v et à l’évolution de cette dernière dans le temps. Le travail se divise ainsi en trois parties, pour chaque un article a été rédigé : 1. Développement d’une séquence Doppler ultrarapide : La séquence se base sur l’utilisation d’ondes divergentes qui permettent d’atteindre une cadence d’image élevée. Associée à la vortographie, une méthode pour localiser le centre du vortex diastolique et en déduire sa vorticité, nous avons pu suivre la dynamique de la vorticité dans le temps. Cette séquence a permis d’établir une preuve de concept grâce à des acquisitions in vitro et in vivo sur des sujets humains volontaires. 2. Développement d’une séquence triplex : En se basant sur la séquence ultrarapide Doppler, on cherche ici à ajouter des informations supplémentaires, notamment sur le mouvement des parois. La séquence triplex permet non seulement de récupérer le mouvement sanguin avec une haute cadence d’images mais aussi le Doppler tissulaire. Au final, nous avons pu déduire les Doppler couleur, tissulaire, et spectral, en plus d’un Bmode de qualité grâce à la compensation de mouvement. On peut alors observer l’interdépendance entre la dynamique du vortex et celle des parois, en récupérant tous les indices nécessaires sur le même cycle cardiaque avec une acquisition unique. 3. Développement d’un filtre automatique : La quantification de la vorticité dépend directement des vitesses estimées par le Doppler. Or, en raison de leur faible amplitude, les signaux sanguins doivent être filtrés. En effet lors de l’acquisition les signaux sont en fait une addition des signaux sanguins et tissulaires. Le filtrage est une étape essentielle pour une estimation précise et non biaisée de la vitesse. La dernière partie de ce doctorat s’est donc concentrée sur la mise au point d’un filtre performant qui se base sur les dimensions spatiales et temporelles des acquisitions. On effectue ainsi un filtrage du tissu mais aussi du bruit. Une attention particulière a été portée à l’automatisation de ce filtre avec l’utilisation de critères d’information qui se basent sur la théorie de l’information. / Heart disease is one of the leading causes of death in the world (first cause in North America [192]), and causes high health care costs for society. The prevalence of heart failure increases dramatically with age and, due to the ageing of the population, will remain a major concern in the future, not only for developed countries, but also for developing countries. It is therefore crucial to have a good understanding of its mechanism to obtain an early diagnosis and a better prognosis for patients. Diastolic dysfunction is one of the variations of heart failure and leads to insufficient filling of the ventricle. To better understand the dysfunction, several studies have examined the blood motion in the ventricle. It is known that at the beginning of diastole, the filling flow creates a vortex pattern known as a vortex ring. This development of the ring by blood flow after passage through a valve was first described in 1513 by Leonardo Da Vinci (Fig. 0.1). After molding a glass phantom in an aorta and adding seeds to visually observe the flow through the phantom, he could describe the vortex ring development of the blood coming out of the aortic valve. His work was confirmed 500 years later with the emergence of MRI [66]. The same pattern can be observed in the left ventricle when the flow emerges from the mitral valve, referred to as the diastolic vortex. The flow motion (in our case the blood) is directly related to its environment : shape of the ventricle, shape of the valve, stiffness of the walls... There is therefore a growing interest in further studies on this diastolic vortex that could lead to valuable information on diastolic function. The imaging modalities which can be used to visualize the vortex are MRI and ultrasound. This thesis presents the work carried out to allow a better characterization of the diastolic vortex in the left ventricle by Doppler ultrasound imaging. For temporal monitoring of vortex dynamics, a high temporal resolution is required, since the ventricular diastole is about 0.5 s on average for a resting human heart. The quality of Doppler signals is also of utmost importance to get an accurate estimate of the blood flow velocity in the ventricle. To study this vortex, we focused on evaluating the core vorticity evaluation and especially on its evolution in time. The work is divided in three parts, and for each of them an article has been written : 1. Ultrafast Doppler sequence : The sequence is based on diverging waves, which resulted in a high frame rate. In combination with vortography, a method to locate the vortex core and derive its vorticity, the vortex dynamics could be tracked over time. This ix sequence could establish a proof of concept based on in vitro and in vivo acquisitions on healthy human volunteers. 2. Triplex sequence : Based on the ultrafast sequence, we were interested in adding information on the wall motion. The triplex sequence is able to recover not only the blood motion with a high framerate but also tissue Doppler. In the end, we could derive color, tissue, and spectral Doppler, along with a high quality Bmode by using motion compensation. The interdependence between vortex and walls dynamics could be highlighted by acquiring all the required parameters over a single cardiac cycle. 3. Automatic clutter filter : Vorticity quantification depends directly on the estimation of Doppler velocity. However, due to their low amplitude, blood signals must be filtered. Indeed, acquired signals are actually an addition of tissue and blood signals. Filtering is a critical step for an unbiased and accurate velocity estimation. The last part of this doctoral thesis has focused on the design of an efficient filter that takes advantage of the temporal and spatial dimensions of the acquisitions. Thus the tissue alongside the noise is removed. Particular care was taken to automatize the filter by applying information criteria based on information theory.

Pianists often have trouble in determining where a phrase ends, or in other words, cadence identification. This is especially true of certain cadences that can be considered either as half cadences or authentic cadences. This analytically ambiguous cadential point can result in different performance decisions, so pianists should make informed decisions about what kind of cadence it is. This study aims to investigate such cadential ambiguity shown at points of phrase boundaries by focusing on Chopin's Piano Sonata No. 2 in B-flat minor, Op. 35, first movement. I offer both possibilities (a half cadence or an authentic cadence) at the phrase ending, suggesting a performance-related strategy based on each possibility. My objective is not to support only one cadential status, but to bring up the cadential problem from the analytical perspective and to demonstrate how cadence identification affects performance results. The dissertation is divided into two parts: analysis and performance, so it relies on a combined method of analytical terminologies and performance-related musical elements. In the analysis, the terminology of William Caplin is employed. The performance part refers to several method books written by prestigious piano pedagogues. After an introduction in Chapter 1, Chapter 2 reviews some literature on cadences. Chapter 3 specifically analyzes the first movement of Chopin's second sonata by means of Caplin's terminologies. Chapter 4 provides a performance-related method and Chapter 5 deals with a practical performance strategy.

No description available.

This thesis presents the design of a mixed-signal CMOS multiplier implemented with short-channel PMOS transistors. The multiplier presented here forms the product of a differential input voltage and a five-bit digital code. A TSMC 0.18 µm MOSFET model is used to simulate the circuit in Cadence Design Systems. The research presented in this thesis reveals a configuration that allows the multiplier to run at a speed of 8.2 GHz with end-point nonlinearity less than 5%. The high speed and low nonlinearity make this circuit ideal for applications such as filtering and digital to analog conversion.

Many modern digital systems use forms of CMOS logical implementation due to the straight forward design nature of CMOS logic and minimal device area since CMOS uses fewer transistors than other logic families. To achieve high-performance requirements in mixed-signal chip development and quiet, noiseless circuitry, this thesis provides an alternative toCMOSin the form of MOS Current Mode Logic (MCML). MCML dissipates constant current and does not produce noise during value changing in a circuit CMOS circuits do. CMOS logical networks switch during clock ticks and with every device switching, noise is created on the supply and ground to deal with the transitions. Creating a noiseless standard cell library with MCML allows use of circuitry that uses low voltage switching with 1.5V between logic levels in a quiet or mixed-signal environment as opposed to the full rail to rail swinging of CMOS logic. This allows cohesive implementation with analog circuitry on the same chip due to constant current and lower switching ranges not creating rail noise during digital switching. Standard cells allow for the Cadence tools to automatically generate circuits and Cadence serves as the development platform for the MCML standard cells. The theory surrounding MCML is examined along with current and future applications well-suited for MCML are researched and explored with the goal of highlighting valid candidate circuits for MCML. Inverters and NAND gates with varying current drives are developed to meet these specialized goals and are simulated to prove viability for quiet, mixed-signal applications. Analysis and results show that MCML is a superior implementation choice compared toCMOSfor high speed and mixed signal applications due to frequency independent power dissipation and lack of generated noise during operation. Noise results show rail current deviations of 50nA to 300nA during switching over an average operating current of 20µA to 80µA respectively. The multiple order of magnitude difference between noise and signal allow the MCML cells to dissipate constant power and thus perform with no noise added to a system. Additional simulated results of a 31-stage ring oscillator result in a frequency for MCML of 1.57GHz simulated versus the 150.35MHz that MOSIS tested on a fabricated 31-stage CMOS oscillator. The layouts designed for the standard cell library conform to existing On Semiconductor ami06 technology dimensions and allow for design of any logical function to be fabricated. The I/O signals of each cell operate at the same input and output voltage swings which allow seamless integration with each other for implementation in any logical configuration.

A digital system is often required to operate under a specific frequency. A ring oscillator can be helpful in this circumstance because it can generate a signal with a specific frequency. However, a ring oscillator is also sensitive to the environment temperature. With the increasing requirement of accuracy and stability, many approaches appear worldwide to make a temperature-insensitive ring oscillator. This thesis project presents an approach to compensate the temperature effect on a Current Starved Ring Oscillator(CSRO). More concretely, we researched how to achieve temperature compensation for CSRO in a digitally-controlled configuration. A Phase Frequency Detector (PFD) block is adapted to sense the frequency difference between the reference frequency and CSRO frequency. Two Charge Pumps (CP)are used to quantify the difference in voltage signal. A Dynamic Comparator block compares the signals from CPs. A following Bidirectional Counter block can count up or down to change the current in CSRO by a four-bit signal. In the end, the CSRO can generate an oscillating signal at the appropriate frequency after some adaptation time. This proposed circuit was realized with AMS 0.35 um CMOS technology and simulated using the Cadence tools. Power consumption, temperature compensation analysis and voltage supply compensation analysis under different temperatures are also performed in the project.