Wireless sensor networks has been one of the major research topics in recent years because of its great potential for a wide range of applications. In some application scenarios, sensor nodes intend to report the sensing data to a far-field destination, which cannot be realized by traditional transmission techniques. Due to the energy limitations and the hardware constraints of sensor nodes, distributed transmit beamforming is considered as an attractive candidate for long-range communications in such scenarios as it can reduce energy requirement of each sensor node and extend the communication range. However, unlike conventional beamforming, which is performed by a centralized antenna array, distributed beamforming is performed by a virtual antenna array composed of randomly located sensor nodes, each of which has an independent oscillator. Sensor nodes have to coordinate with each other and adjust their transmitting signals to collaboratively act as a distributed beamformer. The most crucial problem of realizing distributed beamforming is to achieve carrier phase alignment at the destination. This thesis will investigate distributed beamforming from both theoretical and practical aspects. First, the bit error ratio performance of distributed beamforming with phase errors is analyzed, which is a key metric to measure the system performance in practice. We derive two distinct expressions to approximate the error probability over Rayleigh fading channels corresponding to small numbers of nodes and large numbers of nodes respectively. The accuracy of both expressions is demonstrated by simulation results. The impact of phase errors on the system performance is examined for various numbers of nodes and different levels of transmit power. Second, a novel iterative algorithm is proposed to achieve carrier phase alignment at the destination in static channels, which only requires one-bit feedback from the destination. This algorithm is obtained by combining two novel schemes, both of which can greatly improve the convergence speed of phase alignment. The advantages in the convergence speed are obtained by exploiting the feedback information more efficiently compared to existing solutions. Third, the proposed phase alignment algorithm is modified to track time-varying channels. The modified algorithm has the ability to detect channel amplitude and phase changes that arise over time due to motion of the sensors or the destination. The algorithm can adjust key parameters adaptively according to the changes, which makes it more robust in practical implementation.

Changes within and outside of agricultural education were analyzed between 2009-2014 which coincided with a reduction of male pre-service agricultural teachers. Under the lens of the Theory of Gender Re-alignment, special attention was given to changes in legislation, curriculum, recruitment, and economic factors which relate to structural and cultural changes within agricultural education. The Changes identified in this study explain why male students are being outperformed by female students at a two to one ratio in regards to agricultural education degrees obtained.

Durant cette thèse, nous nous sommes intéressés à la problématique de la captation de mouvement sans marqueurs. Une approche classique est basée sur l'utilisation d'un modèle prédéfini du sujet, et est divisée en deux phases : celle d'initialisation, où la pose initiale du sujet est estimée, et celle de suivi, où la pose actuelle du sujet est estimée à partir des précédentes. Souvent, la phase d'initialisation est faite manuellement, rendant impossible l'utilisation en direct, ou nécessite des actions spécifiques du sujet. Nous proposons une phase d'initialisation automatique et temps-réel, utilisant l'information topologique extraite par squelettisation d'une reconstruction 3D du sujet. Cette information est représentée sous forme d'arbre (arbre de données), qui est mis en correspondance avec un arbre utilisé comme modèle, afin d'identifier les différentes parties du sujet. Pour obtenir une telle méthode, nous apportons des contributions dans les domaines de la topologie discrète et de la théorie des graphes. Comme notre méthode requiert le temps réel, nous nous intéressons d'abord à l'optimisation du temps de calcul des méthodes de squelettisation, ainsi qu'à l'élaboration de nouveaux algorithmes rapides fournissant de bons résultats. Nous nous intéressons ensuite à la définition d'une mise en correspondance efficace entre l'arbre de données et celui décrivant le modèle. Enfin, nous améliorons la robustesse de notre méthode en ajoutant des contraintes novatrices au modèle. Nous terminons par l'application de notre méthode sur différents jeux de données, démontrantses propriétés : rapidité robustesse et adaptabilité à différents types de sujet / This manuscript deals with the problem of markerless motion capture. An approach to thisproblem is model-based and is divided into two steps : an initialization step in which the initialpose is estimated, and a tracking which computes the current pose of the subject using infor-mation of previous ones. Classically, the initialization step is done manually, for bidding the possibility to be used online, or requires constraining actions of the subject. We propose an automatic real-time markerless initialization step, that relies on topological information provided by skeletonization of a 3D reconstruction of the subject. This topological information is then represented as a tree, which is matched with another tree used as modeldescription, in order to identify the different parts of the subject. In order to provide such a method, we propose some contributions in both digital topology and graph theory researchfields. As our method requires real-time computation, we first focus on the speed optimization of skeletonization methods, and on the design of new fast skeletonization schemes providing good results. In order to efficiently match the tree representing the topological information with the tree describing the model, we propose new matching definitions and associated algorithms. Finally, we study how to improve the robustness of our method by the use of innovative con-straints in the model. This manuscript ends by a study of the application of our method on several data sets, demon-strating its interesting properties : fast computation, robustness, and adaptability to any kindof subjects

Virtual physical education (VPE) offerings have grown for over a decade in the United States, but there has been little empirical knowledge shared, specifically regarding the design of courses to support and validate these expanding programs (Buschner, 2006; Mohnsen, 2012a; b; Mosier, 2012; Mosier & Lynn, 2012). Most VPE research has been conducted at the Florida Vir- tual School (FLVS), but few studies have been completed regarding VPE in Georgia (Watson Pape, Murin, Gemin, & Vashaw, 2014). Due to the lack of research along with the growth in VPE (Daum, 2014; Mosier, 2012; Watson et al., 2014), the purpose of this study was to perform an initial, descriptive examination of a district virtual personal fitness course in Georgia and determine the degree to which its design aligns with the criteria established by the National Association of Sport and Physical Education (NASPE) Initial Guidelines for Online Physical Education (PE) (2007). This study aimed to answer the following overarching research question: To what degree does the design of the virtual personal fitness course align with the NASPE Initial Guide- lines for Online PE? A thorough document analysis of the course website and student activity tracking data along with semi-structured interviews and electronic virtual personal fitness student and teacher anonymous survey questionnaires provide a detailed description of the course and illustrate the degree to which its design aligns with the 10 guidelines. Triangulated results of this study indicate superficial strong alignment with eight of the 10 guidelines, and moderate alignment with two of the 10 guidelines, but more evidence is needed to confirm alignment in practice. The researcher concludes that revisions to the guidelines are necessary to better capture evidence of alignment to further promote quality, optimal student learning and best practice in single district virtual personal fitness environments. The results of this study contribute to the over- all knowledge base of single district virtual personal fitness programs and set the stage for future research endeavors to investigate this phenomena and add to the literature in this area.

Organizations that have come to depend on legacy systems face quite a paradoxical problem. Maintaining the system might prove ineffective in accommodating necessary changes, but a system migration project is expensive and incurs a high amount of risk. Organizations are therefore hesitant to respond to the legacy system problem by undertaking action. Legacy system are often not causing their organization any problems at present, but a focus on the future with regard to the legacy system problem is lacking. This results in IT systems reaching an end-of-life state. The research therefore set out to explore a future-oriented perspective on legacy systems by means of observation, a literature review and a survey. The researcher found the key concept of a future-oriented perspective to be that any system that is limiting an organization to grow and innovate can be regarded as a legacy system. A framework to designate legacy status to IT systems is proposed in order to guide practitioners to acknowledge a problematic IT system to facilitate appropriate response at the right time. In relation to a future-oriented perspective, when to designate legacy status is best determined according to the system’s flexibility towards change and the alignment of the system with the business. In that regard, IT systems are end-of-life systems when they are too inflexible to change, and as a result become unaligned with either current operations or a future business opportunity or need.

Sequence alignment is one of the most intensely studied problems in bioinformatics, and is an important step in a wide range of analyses. An issue that has gained much attention in recent years is the fact that downstream analyses are often highly sensitive to the specific choice of alignment. One way to address this is to jointly sample alignments along with other parameters of interest. In order to extend the range of applicability of this approach, the first chapter of this thesis introduces a probabilistic evolutionary model for protein structures on a phylogenetic tree; since protein structures typically diverge much more slowly than sequences, this allows for more reliable detection of remote homologies, improving the accuracy of the resulting alignments and trees, and reducing sensitivity of the results to the choice of dataset. In order to carry out inference under such a model, a number of new Markov chain Monte Carlo approaches are developed, allowing for more efficient convergence and mixing on the high-dimensional parameter space. The second part of the thesis presents a directed acyclic graph (DAG)-based approach for representing a collection of sampled alignments. This DAG representation allows the initial collection of samples to be used to generate a larger set of alignments under the same approximate distribution, enabling posterior alignment probabilities to be estimated reliably from a reasonable number of samples. If desired, summary alignments can then be generated as maximum-weight paths through the DAG, under various types of loss or scoring functions. The acyclic nature of the graph also permits various other types of algorithms to be easily adapted to operate on the entire set of alignments in the DAG. In the final part of this work, methodology is introduced for alignment-DAG-based sequence annotation using hidden Markov models, and RNA secondary structure prediction using stochastic context-free grammars. Results on test datasets indicate that the additional information contained within the DAG allows for improved predictions, resulting in substantial gains over simply analysing a set of alignments one by one.

The focus of the projects presented here was to develop possible solutions to three issues commonly encountered during chemometric analysis of comprehensive two-dimensional liquid chromatography diode array detector (LCxLC-DAD) data. The focus of the first project was to determine a means of performing background correction that removed two background ridges. The methods of simply subtracting out a mean blank sample, singular value decomposition based background correction (SVD-BC) and asymmetrically weighted least squares (AWLS) were compared. AWLS was found to be the only background correction technique to fully remove the ridges. However, AWLS was also found to attenuate the peak intensity by approximately 25% due to over fitting of the background at the lower wavelengths. The focus of the second project was the investigation of five common interpolation strategies for the reconstruction of the sampled first dimension peak. The interpolation strategy that best reproduced the original first dimension retention time was Gaussian fitting. This was expected given that the simulated data set was generated using a Gaussian model for the peak shape. An algorithm, semi-automated alignment method (SAAM), was then developed that allowed for each peak to be aligned independently of the other peaks in the data set. SAAM was validated using both simulated and experimental data. The simulated results indicated that SAAM produced percent recoveries close to 100%. SAAM was also compared to iterative key set factor analysis-alternating least squares (IKSFA-ALS) for the analysis of phenytoin in a waste water treatment plant effluent. SAAM produced a concentration of 26±3 ppb compared to 39±9 ppb from IKSFA-ALS. While these results are very different, the result produced by SAAM is still within the experimental error of the reference 2D-LC/MS/MS method, 42±19. Finally, SAAM was compared to two existing literature methods. A mixture of simulated and experimental data sets was used to measure the accuracy and precision of the results. SAAM was found to be impacted less by intra- and inter-sample retention time shifting then PARAFAC2. SAAM and shifted candecomp/PARAFAC were found to produce very similar results. However, SAAM was found to experience some difficulty producing accurate and precise results with some of the experimental data sets.

This study examines the potential of Schwann cells (SCs) to be manipulated by electric fields (EFs) in order to improve recovery from spinal cord injury (SCI). It had long been believed that the central nervous system (CNS) is incapable of regeneration, but recent studies have proven otherwise. SC transplants are known to be useful in promoting axon regeneration after SCI, but is not sufficient for functional recovery. EFs are known to exist in vivo, and have been known to drastically affect the morphology and behavior of cells in various tissues. It was the hypothesis of this study that the conditioning and observed alignment of SCs was a reproducible phenomenon that could promote the growth of axons. It was found that SCs could be aligned at various field strengths and preliminary data suggest that aligned SCs increased the length and directionality of axons extending from DRG explants.

INTRODUCTION: Alors qu’il existe aujourd'hui différents genres de traitements orthodontiques esthétiquement acceptables, les patients s'inquiètent maintenant de la durée des traitements. L'appareil AcceleDent® a été introduit sur le marché par OrthoAccel Technologies en 2009. Ce dispositif, placé entre les dents pendant 20 minutes par jour, vibre à une fréquence de 30 Hz et est préconisé pour accélérer le traitement. L’objectif primaire est d’évaluer la précision de la simulation ClinCheck® par rapport aux résultats finaux réels pour les deux groupes. L’objectif secondaire est de déterminer si le résultat final est influencé par une progression plus rapide des gouttières d’alignement. MATÉRIELS & MÉTHODES: Une étude rétrospective qui comprend 38 patients traités avec la technique Invisalign®. Le groupe expérimental, c’est-à-dire celui qui utilise l’AcceleDent®, comprend 13 patients tandis que le groupe contrôle inclut 25 patients. La sévérité de la malocclusion a été quantifiée avec le «Discrepancy Index de l’ABO». Concernant la prédiction des résultats de la simulation ClinCheck® et le résultat du traitement final, l’«Objective Grading System de l’ABO » a été utilisé pour quantifier ces derniers. Toutes les données ont été prises à partir du logiciel OrthoCAD (Cadent, Fairview, NJ). RÉSULTATS ET DISCUSSION: Il n'y a pas de différence statistiquement significative entre la malocclusion des 2 groupes. (p=0,761). Pour les résultats finaux, il existe une différence statistiquement significative. L'alignement est meilleur dans le groupe contrôle (p=0,002). Au sein de chaque groupe, la différence entre les résultats prédits et réels n’est pas statistiquement significative (p=0,056). L’utilisation de l’AcceleDent® semble donner un surplomb horizontal plus proche de celui prédit, cependant ceci n’est pas cliniquement significatif. CONCLUSION: L’utilisation de l’appareil AcceleDent® combiné à une progression plus rapide des coquilles aux sept jours influence négativement l’alignement final chez les patients traités par la technique Invisalign®. / INTRODUCTION: While there are presently many different options for aesthetic orthodontic treatment, patients are now concerned with the length of treatment. The AcceleDent® device was introduced by OrthoAccel Technologies in 2009. This device is placed between the teeth for 20 minutes a day, vibrates at a frequency of 30 Hz and is recommended to accelerate orthodontic treatment. This study’s primary objective is to evaluate the accuracy of the ClinCheck® simulation versus the actual final results. The secondary objective is to determine if the end result is influenced by the increased rate of treatment progression with the aligners. MATERIALS AND METHODS: A retrospective study design was used with 38 patients treated with Invisalign®. The experimental group consisted of 13 patients, while the control group included 25 patients. The severity of malocclusion was quantified with the Discrepancy Index approved by the American Board of Orthodontics. In addition, the ABO’s Objective Grading System was used to compare the prediction of the final result provided by the ClinCheck® simulation and the actual final treatment result. All data were taken from the OrthoCAD software (Cadent, Fairview, NJ). RESULTS AND DISCUSSION: There is no statistically significant difference between the two groups regarding their initial malocclusion (p= 0.761). For the final results, there is a statistically significant difference. The alignment is better in the control group (p = 0.002). Within each group, the difference between the predicted and the actual results are not statistically significant (p = 0.056). The use of AcceleDent® seems to give an overjet similar to that which was predicted; however, this finding is not clinically significant. CONCLUSION: The use of the AcceleDent® combined with changing aligners every seven days negatively influence the final alignment in patients treated with Invisalign®.

La gouvernance des SI a été étudiée par les chercheurs et par les praticiens sous différents angles de vue. Du point de vue académique, des études ont été faites sur les structures de prise de décision, sur les facteurs impactants et sur les caractéristiques de la gouvernance des SI. Les praticiens se sont plutôt intéressés aux mécanismes de gouvernance de SI. Ainsi plusieurs approches et référentiels pour la gouvernance des SI ont vu le jour, ayant chacun des objectifs spécifiques (gestion de projet, gestion de service informatique, audit et contrôle de SI, maturité des processus, gestion de risques, qualité, etc.). Ces approches sont en général basées sur une vue processus. Comme elles affichent des objectifs différents, on peut observer, dans certaines grandes entreprises, des projets de mise en place simultanée et indépendante de plusieurs approches processus. Dans un tel cas, malgré les bénéfices apportés à l’entreprise par chacune des approches, on peut supposer que vont apparaître des problèmes de cohérence. Mais aucune étude ne semble avoir été faite pour savoir quels sont les apports et les conséquences d'une mise en place simultanée de différentes approches processus dans l'entreprise. De façon plus large, malgré la richesse de la recherche sur la gouvernance des SI, il n y a pas eu d’étude prenant la gouvernance des SI dans sa globalité et sous tous les angles de vue. Dans cette thèse, nous allons donc étudier la question suivante : Est-il pertinent d’adopter une approche globale de la gouvernance des SI ? Si oui, comment peut-on procéder ? Deux études sur le terrain chez deux grands opérateurs de télécommunications européens de deux ans chacune ont été menés. La première est une recherche-intervention en tant que observateur-participant complet, et la deuxième est une étude de cas avec une position d’observateur privilégié. Ces deux études ont permis d’apporter des éléments de réponses à cette question. La thèse est structurée de la façon suivante. D’abord, une étude approfondie de la littérature sur la gouvernance des SI (ch.1) a conduit à établir un méta-modèle unificateur de la gouvernance des SI (ch.2). La problématique (ch.3) et la méthodologie de recherche (ch.4) sont ensuite exposées. Puis, la première étude terrain teste la pertinence et la faisabilité de la mise en place d’une approche unificatrice de la gouvernance des SI : elle comporte une phase de diagnostic (ch.5) et une phase thérapeutique (ch.6). La seconde étude terrain permet d’explorer les conséquences d’une situation de mises en place simultanées et non coordonnées de plusieurs approches relevant de la gouvernance des SI : les données collectées sont décrites (ch.7) et analysées (ch.8). La thèse s’achève par la proposition du modèle GISUF « Governance of Information Systems Unified Framework», qui constitue une approche permettant de considérer la gouvernance des SI dans sa globalité. Après une première description de GISUF (ch.9), nous détaillons le système d’information sur lequel s’appuie la gouvernance, c’est-à-dire le référentiel de gouvernance (ch.10). Puis, nous décrivons le fonctionnement idéal d’une gouvernance globale unifiée à travers ses processus (ch.11). Enfin, nous exposons comment on peut mettre en place GISUF dans l’entreprise (ch.12). La conclusion indique les apports et les limites de la recherche / IS governance has been studied by researchers and practitioners from different angles. From the academic point of view, studies were made on the structures of decision making, the impacting factors, and the characteristics of IS governance. Practitioners are rather interested in the mechanisms of IS governance. Thus, several approaches and frameworks for IS governance have emerged, each with specific objectives (project management, service management, audit and control of IS, process maturity, risk management, quality, etc..). These approaches are generally based on a process view. As these approaches have different objectives, several process approaches simultaneous implementation projects can be observed in some large companies. In such case, despite the benefits of each of these approaches, we can assume that coherence problems will appear. Yet, no study has been conducted to find out what are the contributions and the consequences of several process approaches simultaneous implementation. More broadly, despite the richness of the research on IS governance, there has been no study that considers all the angles of view of the IS governance in a holistic manner. In this PhD, we will therefore consider the following question: Is it appropriate to adopt a holistic approach to IT governance? If so, how can we proceed? Two field studies at two major European telecommunications operators of two years each were conducted. The first is an action-research as a full participant-observer, and the second is a case study with a position of privileged observer. These two field studies permitted to answer this question. This thesis is structured as follows. First, a thorough review of the IS governance literature (ch.1) led to establish a unifying meta-model of IS governance (ch.2). The research problem (ch.3) and research methodology (ch.4) are then exposed. Then, the first field study tests the relevance and feasibility of establishing a unifying approach of IS governance: it consists in a diagnosis phase (ch.5) and a therapeutic phase (ch.6). The second field study explores the consequences of a situation where several IS governance approaches were implemented simultaneously and without coordination: the data collected are outlined (ch.7) and analyzed (ch.8). The thesis concludes with the proposed model GISUF "Governance of Information Systems Unified Framework", which is an IS governance holistic approach. After an initial description of GISUF (ch.9), we detail the information system on which governance is based, that is to say, the repository of governance (ch.10). Then, we describe the ideal operational functioning of the unified holistic governance through its processes (ch.11). Finally, we discuss how we can implement GISUF in an organization (ch.12). The conclusion shows the contributions and limitations of research