Abstract Academic Leadership and Development Academy (ALDA) was instituted by the Tau Lambda-at-Large Chapter Sigma Theta Tau International (STTI). In 2011-2012 ALDA intended goal was to emancipate participants to be able to take professional leadership positions, generate a funded research project, professional networking muscle and collaboration, including publishing in an accredited journal. The purpose of the study was to explore and describe the needs of the fellows enrolled for the 2011-2012 ALDA leadership programme. The word ‘fellow’ refers to all candidates who were selected to participate in the ALDA programme. The programme was tailor-made to develop and prepare professional nurses for middle or high level leadership positions within the academic environment. Four African universities and colleges were involved. The research design was qualitative, exploratory, and descriptive in nature. The target population included all 2011-2012 fellows of the ALDA of the Sigma Theta Tau Lambda-at-Large Chapter Africa. The sample consisted of all 14 fellows of the 2011-2012 ALDA who were involved in programme. This programme was the first of its kind in Africa engineered by ALDA in Africa in 2011. Data gathering was a self-report through naïve sketches. Tesch’s eight steps of data analysis were applied. An independent coder was engaged to improve trustworthiness of the data. The results showed that fellows needed professionalism and recognition; communication and setting the stage; and more collaboration with research expects. At first the programme did not have a clear curriculum content outlined and as such fellows were dissatisfied for some time which affected the progress as expected by both the fellows and the faculty. Faculty refers to experts involved in the programme. However, fellows managed to work cooperatively with one another, thus promoting a social learning environment and providing opportunities of collaborative research studies in the future.

Cloud services are popular for hosting applications because they offer simplicity and cost efficiency. There are a lot of different providers offering many different services, which can make it hard to find the one most suitable for you. To make informed decisions you need to evaluate different services. This project evaluates a cloud service, called Amazon Lambda, from one of the biggest cloud service providers. Amazon Lambda is a simple service which runs one function in response to an event. In this project it is evaluated on suitability, performance and cost. To evaluate suitability, a certain kind of applications, games, were selected. The game industry is innovative and put high requirements on performance. A few simple Lambda functions were implemented and integrated in a prototype game. Some calculations were made for determining the cost of hosting such a game on Amazon Lambda. A few tests were implemented and run in order to further evaluate the performance.

Master of Science / Department of Computing and Information Sciences / William Hsu / The Lambda Architecture is the new paradigm for big data, that helps in data processing with a balance on throughput, latency and fault-tolerance. There exists no single tool that provides a complete solution in terms of better accuracy, low latency and high throughput. This initiated the idea to use a set of tools and techniques to build a complete big data system. The Lambda Architecture defines a set of layers to fit in a set of tools and techniques rightly for building a complete big data system: Speed Layer, Serving Layer, Batch Layer. Each layer satisfies a set of properties and builds upon the functionality provided by the layers beneath it. The Batch layer is the place where the master dataset is stored, which is an immutable and append-only set of raw data. Also, batch layer pre-computes results using a distributed processing system like Hadoop, Apache Spark that can handle large quantities of data. The Speed Layer captures new data coming in real time and processes it. The Serving Layer contains a parallel processing query engine, which takes results from both Batch and Speed layers and responds to queries in real time with low latency. Stack Overflow is a Question & Answer forum with a huge user community, millions of posts with a rapid growth over the years. This project demonstrates The Lambda Architecture by constructing a data pipeline, to add a new “Recommended Questions” section in Stack Overflow user profile and update the questions suggested in real time. Also, various statistics such as trending tags, user performance numbers such as UpVotes, DownVotes are shown in user dashboard by querying through batch processing layer.

The presented work contains a survey of the so far known results about the operator inequalities of the type "good λ", "better good λ" and "rearranged good λ" on the function spaces over the Euclidean space with the Lebesgue measure and their corollaries in the form of more complex operator inequal- ities and norm estimates. However, the main aim is to build similar theory for the Riesz potential operator on the function spaces over the quasi-metric space with the so-called "doubling" measure. Combining the corollaries of this theory with the known norm estimates we obtain the boundedness for the Riesz potential operator on the Lebesgue and Lorentz spaces.

"Abstraction creates custom programming languages that facilitate programming for specific problem domains. It is traditionally partitioned according to a two-phase model of program evaluation, into syntactic abstraction enacted at translation time, and semantic abstraction enacted at run time. Abstractions pigeon-holed into one phase cannot interact freely with those in the other, since they are required to occur at logically distinct times. Fexprs are a Lisp device that subsumes the capabilities of syntactic abstraction, but is enacted at run-time, thus eliminating the phase barrier between abstractions. Lisps of recent decades have avoided fexprs because of semantic ill-behavedness that accompanied fexprs in the dynamically scoped Lisps of the 1960s and 70s. This dissertation contends that the severe difficulties attendant on fexprs in the past are not essential, and can be overcome by judicious coordination with other elements of language design. In particular, fexprs can form the basis for a simple, well-behaved Scheme-like language, subsuming traditional abstractions without a multi-phase model of evaluation. The thesis is supported by a new Scheme-like language called Kernel, created for this work, in which each Scheme-style procedure consists of a wrapper that induces evaluation of operands, around a fexpr that acts on the resulting arguments. This arrangement enables Kernel to use a simple direct style of selectively evaluating subexpressions, in place of most Lisps' indirect quasiquotation style of selectively suppressing subexpression evaluation. The semantics of Kernel are treated through a new family of formal calculi, introduced here, called vau calculi. Vau calculi use direct subexpression-evaluation style to extend lambda calculus, eliminating a long-standing incompatibility between lambda calculus and fexprs that would otherwise trivialize their equational theories. The impure vau calculi introduce non-functional binding constructs and unconventional forms of substitution. This strategy avoids a difficulty of Felleisen's lambda-v-CS calculus, which modeled impure control and state using a partially non-compatible reduction relation, and therefore only approximated the Church-Rosser and Plotkin's Correspondence Theorems. The strategy here is supported by an abstract class of Regular Substitutive Reduction Systems, generalizing Klop's Regular Combinatory Reduction Systems."

Monitoring data-intensive scientific infrastructures in real-time such as jobs, data transfers, and hardware failures is vital for efficient operation. Due to the high volume and velocity of events that are produced, traditional methods are no longer optimal. Several techniques, as well as enabling architectures, are available to support the Big Data issue. In this respect, this thesis complements existing survey work by contributing an extensive literature review of both traditional and emerging Big Data architecture. Scalability, low-latency, fault-tolerance, and intelligence are key challenges of the traditional architecture. However, Big Data technologies and approaches have become increasingly popular for use cases that demand the use of scalable, data intensive processing (parallel), and fault-tolerance (data replication) and support for low-latency computations. In the context of a scalable data store and analytics platform for monitoring data-intensive scientific infrastructure, Lambda Architecture was adapted and evaluated on the Worldwide LHC Computing Grid, which has been proven effective. This is especially true for computationally and data-intensive use cases. In this thesis, an efficient strategy for the collection and storage of large volumes of data for computation is presented. By moving the transformation logic out from the data pipeline and moving to analytics layers, it simplifies the architecture and overall process. Time utilised is reduced, untampered raw data are kept at storage level for fault-tolerance, and the required transformation can be done when needed. An optimised Lambda Architecture (OLA), which involved modelling an efficient way of joining batch layer and streaming layer with minimum code duplications in order to support scalability, low-latency, and fault-tolerance is presented. A few models were evaluated; pure streaming layer, pure batch layer and the combination of both batch and streaming layers. Experimental results demonstrate that OLA performed better than the traditional architecture as well the Lambda Architecture. The OLA was also enhanced by adding an intelligence layer for predicting data access pattern. The intelligence layer actively adapts and updates the model built by the batch layer, which eliminates the re-training time while providing a high level of accuracy using the Deep Learning technique. The fundamental contribution to knowledge is a scalable, low-latency, fault-tolerant, intelligent, and heterogeneous-based architecture for monitoring a data-intensive scientific infrastructure, that can benefit from Big Data, technologies and approaches.

Magíster en Ciencias de la Ingeniería, Mención Matemáticas Aplicadas. Ingeniero Civil Matemático / Las curvas autocontractantes (ver definición \ref{autocontractante}) han sido extensamente estudiadas debido a su relación con sistemas dinámicos de tipo gradiente y sus aplicaciones tanto en algoritmos de optimización de tipo descenso (Convergencia del algoritmo Proximal), como de soluciones a encontrar curvas que sean perpendiculares a foliaciones convexas del espacio (ver \cite{daniilidis2010asymptotic}, \cite{daniilidis2015rectifiability}). También, de manera independiente, en la década del 90 los matemáticos Manselli y Pucci trabajaron en estudiar el largo de ciertas curvas, que a posteriori, corresponden exactamente a las curvas autocontractantes salvo porque estén revertidas en orientación y supuestas rectificables de antemano (ver \cite{manselli1991maximum}). La rectificabilidad en curvas irregulares resulta ser un problema complicado dado que no hay una caracterización de esta propiedad salvo hipótesis fuertes, como del estilo que sean diferenciables, o bien, que posean curvatura finita (ver \cite{GTIC}, Capítulo 5). Este trabajo está enfocado en extender lo más posible una técnica que prueba rectificabilidad (en un sentido que quedará claro en el capítulo 2), para el caso de las $\lambda$-curvas, que a saber, son curvas en un espacio métrico $\gamma:I\subseteq \R\to (X,d)$, tales que para $t_1,t_2,t_3\in I$, con $t_1<t_2<t_3$, satisfacen: \[d(\gamma(t_1),\gamma(t_2))\leq d(\gamma(t_1),\jo(t_3))+\lambda d(\gamma(t_2),\gamma(t_3)).\] Se puede apreciar que una curva autocontractante con orientación invertida corresponde al caso $\lambda=0$, por lo tanto la clase de $\lambda$-curvas es más amplia y su estudio contiene lo anterior mencionado. También, se presentan propiedades geométricas de las $\lambda$-curvas y su estrecha relación con curvas autocontractantes definidas en espacios de Banach de dimensión infinita. En esta misma línea, se muestran 2 ejemplos para probar que las curvas autocontractantes definidas sobre espacios de Banach, contenidas en un compacto, no tienen por qué ser rectificables, ni si quiera localmente rectificables.

Cette thèse étudie la construction automatique de représentations sémantiques comme lambda-termes simplement typés. Nous introduisons la sémantique formelle et computationnelle et présentons une tentative de construction sémantique à l'aide d'outils d'inférence. <br />Nous expliquons les limites de cette approche et en proposons une autre, basée sur un outil appelé Nessie. Cet outil construit des représentations sémantiques grâce à un lexique spécifiant le sens des mots et à un arbre guidant la construction. L'implantation de l'outil est présentée et ses résultats sont comparés à ceux du système évoqué plus haut. Nous appliquons ensuite Nessie à deux tâches différentes.<br />D'abord, nous montrons comment il peut être utilisé (avec des outils d'inférence) pour étudier la sémantique du temps et de l'aspect des verbes polonais. Ensuite, nous présentons deux approches de la construction compositionnelle du sens de discours basées sur la théorie des types. Nous montrons que Nessie peut être utilisé pour calculer des représentations de discours dans ces deux formalismes; cette double implantation permet de souligner les points forts et les points faibles de chacune et de les comparer. Enfin, nous prouvons que notre approche de la construction sémantique est compatible avec une large gamme de formalismes syntaxiques: ceux reconnus par une grammaire catégorielle abstraite d'ordre 2. Une conséquence de cette caractérisation est que Nessie peut gérer une large gamme de grammaires inversibles et peut donc, théoriquement, être utilisé aussi bien en génération qu'en analyse. <br />Nous concluons en discutant de la pertinence du lambda calcul simplement<br />typé pour la sémantique des langues naturelles.

Dans cette thèse on s'intéresse surtout aux sémantiques principales du λ-calcul (c'est- a-dire la sémantique continue de Scott, la sémantique stable, et la sémantique fortement stable) mais on introduit et étudie aussi deux nouvelles sémantiques : la sémantique relationnelle et la sémantique indécomposable. Les modèles du λ-calcul pur peuvent être définis soit comme des objets réflexifs dans des catégories Cartésiennes fermées (modèles catégoriques) soit comme des algèbres combinatoires satisfaisant les cinq axiomes de Curry et l'axiome de Meyer-Scott ( λ-modèles). En ce qui concerne les modèles catégoriques, on montre que tout modèle catégorique peut être présenté comme un λ-modèle, même si la ccc (catégorie Cartésienne fermée) sous-jacente n'a pas assez de points, et on donne des conditions su santes pour qu'un modèle catégorique vivant dans une ccc \cpo-enriched" arbitraire ait H pour théorie équationnelle. On construit un modèle catégorique qui vit dans une ccc d'ensembles et relations (sémantique relationnelle) et qui satisfait ces conditions. De plus, on montre que le λ-modèle associe possède des propriétés algébriques qui le rendent apte a modéliser des extensions non-déterministes du -calcul. En ce qui concerne les algèbres combinatoires, on montre qu'elles satisfont une généralisation du Théorème de Représentation de Stone qui dit que toute algèbre combinatoire est isomorphe a un produit Booléen faible d'algèbres combinatoires directement indécomposables. On étudie la sémantique du λ-calcul dont les modèles sont directement indécomposable comme algèbres combinatoires (sémantique indécomposable); on prouve en particulier que cette sémantique est assez générale pour inclure d'une part les trois sémantiques principales et d'autre part les modèles de termes de toutes les λ-théories semi-sensibles. Par contre, on montre aussi qu'elle est largement incomplète. Finalement, on étudie la question de l'existence d'un modèle non-syntaxique du λ-calcul appartenant aux sémantiques principales et ayant une théorie équationnelle ou inéquationnelle r.e. (récursivement énumérable). Cette question est une généralisation naturelle du problème de Honsell et Ronchi Della Rocca (ouvert depuis plus que vingt ans) concernant l'existence d'un modèle continu de λβ ou λβη. On introduit une notion adéquate de modèles effectifs du λ-calcul, qui couvre en particulier tous les modèles qui ont été introduits individuellement en littérature, et on prouve que la théorie inéquationnelle d'un modèle effectif n'est jamais r.e. ; en conséquence sa théorie équationnelle ne peut pas être λβ ou λβη. On montre aussi que la théorie équationnelle d'un modèle effectif vivant dans la sémantique stable ou fortement stable n'est jamais r.e. En ce qui concerne la sémantique continue de Scott, on démontre que la théorie in équationnelle d'un modèle de graphe n'est jamais r.e. et qu'il existe beaucoup de modèles de graphes effectifs qui ont une théorie équationnelle qui n'est pas r.e.

<p>Closed loop fuel injection have been in use for two decades but it's not until the recent five years that the wide band lambda sensor have been utilized. The goal is to explain wide band and discrete lambda sensors in a simple but powerful way. Both sensors are modeled by simple mathematics and accounts for Oxygen, Hydrogen and Carbon monoxide influences. The focus is not just on the output from the sensors, but also on the underlying function. This means that all explanations are thorough and methodical. The function of a wide band lambda sensor is more complicated than a discrete type lambda sensor, therefore it's harder to get correct readings. The model of the wide band lambda sensor is used to evaluate different problems in preparation for the development of an observer. Several potential problem sources are tested and investigated, these include calibration error, pressure error, air leak error, gas sensitivity and fuel errors. To evaluate the potential problems and their ability to explain differences between actual lambda and sensor output, two sensors with differing outputs have been used. The final result is implemented in an ECU.</p><p>The models indicate that the difference between the two sensors is most likely explained by different sensitivity for CO, O2 and H2. This can in turn have one or several explanations. It is suggested that different ability to pump oxygen, different nernst cells or even different controllers can cause this. The reason is not investigated further as this would require a very deep research on the two sensors. Because no usable explanation is found an observer that estimates the offset at stoichiometric conditions, where lambda equals one, is constructed. The observer uses the fact that the switch point of a discrete lambda sensor is insensitive to disturbances. The offset calculation is performed in real time on an ECU. Tools for calibration of the observer are also developed. With the observer the error for the two sensors is roughly halved over the whole spectrum and at stoichiometric conditions, which is the normal operation for an engine, the error was too small to measure.</p><p>Although the wide band lambda sensor is a very complex sensor it is shown that it can be understood with simple mathematics and basic knowledge in chemistry. The developed model agrees well with the real sensor for steady state conditions. For transient conditions, however, the model needs to be refined further. The question why the two sensors differ is discussed but the true origin of the cause remains unsolved. The conclusion is that the error can be drastically reduced with just an offset. It is also shown that when building a lambda sensing device the controller is of equal importance as the sensor element itself. This is due to the sensitivity of surrounding factors that the controller must be able to handle. These effects are specially important for engines running at lambda not equal to 1, for example diesel engines.</p>