For this study, two groups of native Icelandic speakers were compared in terms of the acoustic properties of their English pronunciation of two phonetic phenomena, plosives and pre-aspiration. In English, plosives with the same manner and place of articulation are distinguished by means of a voicing contrast, whereas in Icelandic, plosives are distinguished by means of an aspiration contrast. This study examines whether participants exhibit interlanguage features in their plosive contrasts in English, substituting unaspirated voiceless plosives for voiced counterparts. Furthermore, this study looks at pre-aspiration, a phonetic feature of Icelandic, characterized by glottal friction following a short vowel preceding a fortis plosive (VhC). Pre-aspiration is not a feature of standard English varieties such as general American (GA) or received pronunciation (RP), and as such this study examines whether participants retain pre-aspiration in their English pronunciation or not. Participants numbered 16 in total, and were all L1 speakers of Icelandic, with eight in each group, four male and four female. The groups were divided by means of age differences, with the first group consisting of participants aged 20-26, and the second group of participants aged 44-50. Participants were asked to partake in a short informal interview, to read a short written passage, and to read a word list. The interview and readings were recorded and analysed using spectrograms and waveforms, and subsequently compared with English and Icelandic reference values for voice onset time (VOT), which vary between the two languages, and pre-aspiration duration in Icelandic. The two groups were also compared to determine whether there were any lingering differences between them. The conclusions drawn are that VOT in English and Icelandic may be more similar than assumed, and that participants shorten pre-aspiration duration or neutralize pre-aspiration when speaking English. However, the English production of the features are more similar to Icelandic than English. Furthermore, the results do not indicate any differences between the two age groups in terms of English pronunciation.

Grammar is an important aspect of language learning and is thus of concern in language teaching as well. This study sets out to investigate the kinds of grammatical mistakes Swedish secondary school pupils make in their written production of English and the possible causes behind these different mistakes. Forty essays from pupils in year nine have been used to study the phenomenon of frequently occurring mistakes and their causes, and the salient mistakes have been quantatively and qualitatively accounted for in the study.      Common mistakes found in the material were subject-verb concord mistakes, mistakes involving plural nouns, incorrect article usage as well as problems using prepositions correctly. Interlingual transfer, i.e. negative transfer from the pupils’ L1, proved to be one significant factor causing mistakes in the material. However, other causes could be traced as well, such as intralingual transfer for example.      Consequently, the findings of this study point in the direction of areas which need specific attention in English L2 learning in Swedish classrooms. Thus, the study contributes with valuable insights for English teacher and teacher trainees to consider in their future practice.

Les motoneurones tiennent une place remarquable dans l'organisme : ils constituent l'interface entre le système nerveux central et le système musculaire. Leur excitabilité est une caractéristique primordiale dans le comportement moteur puisqu'elle définit la force musculaire développée en réponse à la commande motrice. Chez la souris, la décharge des motoneurones est marquée par la présence d'oscillations de mode mixte (MMOs) entre les potentiels d'action. Ces MMOs permettent la décharge des motoneurones à basse fréquence et sont responsables d'un régime de décharge particulier nommé zone sous-Primaire, pendant lequel la fréquence de décharge est très variable et le gain de la relation courant-Fréquence élevé. Nous avons étudié les mécanismes responsables de l'apparition de ces MMOs à la fois de manière expérimentale, dans une préparation in vivo de souris anesthésié, incluant l'utilisation du Dynamic Clamp, et théorique, au moyen d'un modèle mono-Compartimental de motoneurone. Nos résultats ont montré que ces MMOs étaient causées par les courants sodiques et potassiques responsables des potentiels d'action et qu'elles émergeaient d'un état de faible excitabilité de la membrane, dû à l'inactivation lente des courants sodiques. Nous avons également montré que le courant de post-Hyperpolarisation pouvait paradoxalement augmenter l’excitabilité des motoneurones et réduire les MMOs en dé-Inactivant le courant sodique. La Sclérose Latérale Amyotrophique (SLA) conduit à la dégénérescence spécifique de ces motoneurones qui s'accompagne d'une vacuolisation de leur arborisation dendritique. L'augmentation précoce de l'excitabilité des motoneurones dans la maladie a largement été évoquée pour rendre compte de leur atteinte. Une hyperexcitabilité, aussi bien d'origine intrinsèque qu'extrinsèque pourrait en effet produire une excitotoxicité délétère pour la cellule. Si une telle modification de l'excitabilité est en cause dans la maladie, elle devrait persister jusqu'aux âges auxquels se produisent les premières dénervations des jonctions neuromusculaires. Nous avons enregistré les propriétés électrophysiologiques des motoneurones dans une préparation in vivo de souris adultes SOD1-G93A, modèle de la SLA. Nos résultats ont montré que leur conductance d'entrée était augmentée dans les jours qui précèdent les premières dénervations de leurs jonctions neuromusculaires. Malgré cela, leur excitabilité n'était pas modifiée. Loin d'être intrinsèquement hyperexcitables, une fraction d'entre eux perdaient même leur capacité à décharger de manière répétée. Nous avons finalement étudié la vacuolisation qui prend place dans les dendrites des motoneurones au cours de la maladie et son lien avec la couverture synaptique. Nous avons montré que la vacuolisation dendritique prenait place avant les dénervations et que la taille des vacuoles augmentait avec l'âge des souris SOD1-G93A. De manière intéressante, cette progression semblait plus rapide dans les motoneurones les plus sensibles à la maladie. Bien que la couverture synaptique n'était pas modifiée au cours de la maladie, nous avons mis en évidence une densité de synapses excitatrices et inhibitrices plus importante sur les régions dendritiques qui se vacuolisent. Ces résultats suggèrent un lien entre l'activité synaptique et la formation de vacuoles dans les motoneurones au cours de la SLA. Les motoneurones ne présentant pas d'hyperexcitabilité intrinsèque, une excitotoxicité d'origine synaptique pourrait alors être responsable de leur dégénérescence. / Motoneurones hold a remarkable position in the organism: they are the interface between the central nervous system and the muscular system. Their excitability is a crucial characteristic in motor behavior since it determines the muscular force produced in response to motor command. In mice, motoneurone discharge is marked by the presence of sub-Threshold oscillations between action potentials which create a behavior of mixed mode oscillations (MMOs). These MMOs allow the motoneurones to fire at low frequency and are responsible for a sub-Primary range of discharge during which the firing frequency is irregular and the slope of current-Frequency relation is steep. We investigated the mechanisms responsible for these MMOs by in vivo recordings in anesthetized mice, using Dynamic Clamp, and by theoretical modelization in a monocompartimental model of motoneurone. Our results showed that MMOs were caused by sodium and potasium currents responsible for action potentials and that they emerged from a state of low membrane excitability caused by a slow inactivation of the sodium current. Paradoxically, we also showed that the after-Hyperpolarization current was able to increase the membrane excitability and to reduce MMOs by de-Inactivating the sodium current. Amyotrophic Lateral Sclerosis (ALS) leads to the specific degeneration of these motoneurones and is accompanied by a vacuolation of their dendritic trees. An early increase in motoneurons excitability during the disease has been widely proposed to account for their degeneration. Indeed, a motoneuron hyperexcitability of intrinsic or extrinsic origin could produce a deleterious excitotoxicity. If such a change of excitability is involved in the disease, it should last until the ages where the first denervation of neuromuscular junctions occurs. We recorded the electrophysiological properties of motoneurones in an in vivo preparation of adult SOD1-G93A mice, model of ALS. Our results showed that their input conductance was increased before the first denervation of their neuromuscular junctions. Nevertheless, their excitability was not modified. Far from being intrinsically hyperexcitable, a fraction of them even lost their ability to discharge repeatedly. We finally studied the vacuolation that takes place in dendrites of motoneurones during the disease and its relation with synaptic coverage. We have shown that the dendritic vacuolation takes place before the denervation and that the size of these vacuoles increases with age in SOD1-G93A mice. Interestingly, this increase was faster in the most vulnerable motoneurones. Although synaptic coverage was not altered in the disease, we ¬revealed higher densities of excitatory and inhibitory synapses on dendritic regions that vacuolate. These results suggest a link between synaptic activity and vacuoles formation in motoneurones during ALS. Motoneurones were not intrinsically hyperexcitable, instead, an excitotoxicity from a synaptic origin may be responsible for their degeneration.

Philosophiae Doctor - PhD / The underlying theme of this thesis is identification, classification, detection and prediction of cellular network faults using state of the art technologies, methods and algorithms.

Leakage current and process variations are two primary hurdles in modern VLSI design. It depends exponentially on process and environmental parameters and hence small variations in these result in a large spread in leakage current of manufactured dies. Traditionally, Exponential Quadratic(EQ) models have been used to model leakage current as a function of process parameters which can model limited non-linearity and hence become inaccurate for large process variations. Artificial Neural Networks (ANN) have shown great promise in modeling circuit parameters for CAD applications. We model leakage with ANN models which perform better than the EQ models for increased process variations. However, the complex nature of the ANN model, with the standard sigmoidal activation functions, does not allow analytical expressions for its mean and variance for the case of Gaussian process variations. We propose the use of a new activation function that allows us to derive an analytical expression for the mean and a semi-analytical expression for the variance of the ANN based leakage model. To the best of our knowledge this is the first result in this direction. All existing SLA frameworks are closely tied to the EQ leakage model and hence fail to work with sophisticated ANN models. We therefore set up an SLA framework that can efficiently work with these ANN models. Results show that the CDF of leakage current of ISCAS'85 circuits can be predicted accurately with the error in mean and standard deviation, compared to Monte Carlo based simulations, being less than 1\% and 2\% respectively across a range of voltage and temperature values. The complexity of our framework is similar to existing SLA frameworks yet more accurate over a larger range of variations. Ignoring the thermal profile of the chip leads to a gross error of nearly 50\% in the prediction of leakage yield. Our neural network model also includes the voltage and temperature as input parameters, thereby enabling voltage and temperature aware statistical leakage analysis (SLA). Similarly leakage CDF can be predicted across a range of supply and body voltages since they are both part of the model. Our framework used analytical techniques to account for local variations and Monte Carlo techniques for global variations and hence it can also be used for Non-Gaussian global variations.

L'informatique en nuage (cloud computing) est un paradigme émergent qui révolutionne l'utilisation et la commercialisation des services informatiques. De nos jours, l'impact socio-économique de l'informatique en nuage et plus particulièrement des services de PaaS (plate-forme en tant que service) devient essentiel, puisque le nombre d'utilisateurs et de fournisseurs des cloud PaaS est en pleine croissance. L'objectif principal des fournisseurs de cloud PaaS est de générer le maximum de profit des services qu'ils fournissent. Cela les oblige à faire face à un certain nombre de défis, tels que la gestion efficace des ressources sous-jacentes et la satisfaction des SLAs (contrat de service) des applications hébergées. Dans cette thèse, nous considérons un environnement PaaS hybride de cloud bursting, où le fournisseur PaaS possède un nombre limité de ressources privées et a la possibilité de louer des ressources publiques. Ce choix permet au fournisseur PaaS d'avoir un contrôle complet sur les services hébergés dans les ressources privées et de profiter de ressources publiques pour gérer les périodes de pointe. De plus, nous proposons une solution rentable pour gérer un tel système PaaS sous des contraintes de SLA. Nous définissons une politique d'optimisation de profit qui, à chaque requête d'un nouveau client, évalue le coût d'hébergement de son application en utilisant les ressources publiques et privées et choisit l'option qui génère le plus de profit. Pendant les périodes de pointe la politique considère deux autres options. La première option consiste à emprunter quelques ressources aux applications en cours d'exécution tout en considérant le paiement de pénalités si leur qualité de service est affectée. La seconde option consiste à attendre que des ressources privées soient libérés tout en considérant le paiement de pénalités si la qualité de service de la nouvelle application est affectée. En outre, nous avons conçu et mis en œuvre une architecture de cloud PaaS, appelée Meryn, qui intègre la politique d'optimisation proposée, supporte le cloud bursting et héberge des applications du type batch et MapReduce. Les résultats de notre évaluation montrent l'efficacité de notre approche dans l'optimisation du profit du fournisseur. En effet, comparée à une approche de base, notre approche fournit jusqu'à 11.59 % et 9.02 % plus de profits pour le fournisseur dans respectivement les simulations et les expériences. / Cloud computing is an emerging paradigm revolutionizing the use and marketing of information technology. As the number of cloud users and providers grows, the socio-economical impact of cloud solutions and particularly PaaS (platform as a service) solutions is becoming increasingly critical. The main objective of PaaS providers is to generate the maximum profit from the services they provide. This requires them to face a number of challenges such as efficiently managing the underlying resources and satisfying the SLAs of the hosted applications. This thesis considers a cloud-bursting PaaS environment where the PaaS provider owns a limited number of private resources and is able to rent public cloud resources, when needed. This environment enables the PaaS provider to have full control over services hosted on the private cloud and to take advantage of public clouds for managing peak periods. In this context, we propose a profit-efficient solution for managing the cloud-bursting PaaS system under SLA constraints. We define a profit optimization policy that, after each client request, evaluates the cost of hosting the application using public and private resources and chooses the option that generates the highest profit. During peak periods the optimization policy considers two more options. The first option is to take some resources from running applications, taking into account the payment of penalties if their promised quality of service is affected. The second option is to wait until private resources become available, taking into account the payment of penalties if the promised quality of service of the new application is affected. Furthermore we designed and implemented an open cloud-bursting PaaS system, called Meryn, which integrates the proposed optimization policy and provides support for batch and MapReduce applications. The results of our evaluation show the effectiveness of our approach in optimizing the provider profit. Indeed, compared to a basic approach, our approach provides up to 11.59% and 9.02% more provider profit in, respectively, simulations and experiments.

Diploma thesis is focused on evaluation of communication streams in the process of application support also known under the term IT support. Thesis is divided into three main parts: In the first part outlines the topic of application support. The definition of term, relation between business and IT and defining the position of application support in the process of information system development along with support services methodologies. The second part is focused on description of typical user of application support, from the side of sponsor as well as from the side of supplier. The following are the main communication streams between both sides as well as inside the supplier team. The third, practical part contains an analysis of application support on a specific project. Discussed are communication barriers, their impact including suggestions for improvement.

Corporate expenses for IT support of marketing are surging every year, and therefore the processes of marketing support, which contain all the technical aspects of marketing campaign execution and measurement, are attracting more attention than before. The diploma thesis introduces a basic overview of direct marketing and marketing support operations in corporations and presents a reference model to help optimize the marketing support processes. The thesis contains a research of theoretical fundamentals of process modelling and reference model building, a basic overview of corporate direct marketing, an analysis of direct marketing processes and the most relevant processes of marketing support. The reference model, which is based on the outputs from both theoretical parts, includes a detailed description of marketing support processes and outlines the process boundaries in the form of SLA. The model is then tested on two case studies, which emphasize the practical opportunities as well as the major benefits of using the model.

A scheduler, as a central components of a computing site, aggregates computing resources and is responsible to distribute the incoming load (jobs) between the resources. Under such an environment, the optimum performance of the system against the service level agreement (SLA) based workloads, can be achieved by calculating the priority of SLA bound jobs using integrated heuristic. The SLA defines the service obligations and expectations to use the computational resources. The integrated heuristic is the combination of different SLA terms. It combines the SLA terms with a specific weight for each term. Theweights are computed by applying parameter sweep technique in order to obtain the best schedule for the optimum performance of the system under the workload. The sweepingof parameters on the integrated heuristic observed to be computationally expensive. The integrated heuristic becomes more expensive if no value of the computed weights result in improvement in performance with the resulting schedule. Hence, instead of obtaining optimum performance it incurs computation cost in such situations. Therefore, there is a need of detection of situations where the integrated heuristic can be exploited beneficially. For that reason, in this thesis we propose a metric based on the concept of utilization, to evaluate the SLA based parallel workloads of independent jobs to detect any impact of integrated heuristic on the workload.

Thesis Price models and SLA for shared services of data centers has as objective to establish best practice, so-called "best practices" of SLA and price models for data center services. Work is divided into two parts, theoretical and practical part. The theoretical section is wants to familiarize the reader with the basic concepts such as outsourcing, reasons and risks of use. I describe the base models for providing IT services as well as pricing models for services as described in the literature. I will focus on data centers and TIER standard categorization, too. The practical part is based on an analysis of information that I got from an interview with the experts working for the biggest data center companies in the Czech Republic. Based on this information, I tried to compile the best practices for creating pricing models for data center services that are actually used in practice. Specifically, the server housing, server hosting and virtual server services. Also, for these services create an SLA that can be used by some data center company in the Czech Republic.