The correct use of morphological suffixes in obligatory contexts reflects linguistic knowledge and competence of speakers. Grammatical knowledge is acquired during a child’s period of primary language acquisition, and may be partial or incomplete due to normal linguistic variation found during acquisition, due to a child’s level of progression through typical chronological development, or due to the presence of language disorders, like specific language impairment (SLI). In the current study, we ask whether characteristics of verbs make it more or less likely that children will correctly use an inflectional morpheme. The morphemes of interest in the current study were third person singular –s (3S) and past tense –ed (ED). Data for analysis were taken from a database of spontaneous language samples collected from 40 children (20 with SLI and 20 developing typically; Hoover, Storkel, & Rice, 2012). Spontaneous language samples were analyzed for the presence or absence of each morpheme in obligatory contexts. For each word item, the uninflected base word was additionally analyzed for a number of phonological and lexical variables. After comparing children with SLI to typically developing peers group differences emerged with respect to the effect of phonological and lexical variables. Moreover, different variables were determined to predict the 3S and ED morphemes. The results are discussed highlighting relevant theoretical and clinical implications.

To increase market penetration, mobile software makers support their popular applications on all major software platforms, which currently include Android, iOS, and Windows Phone. Although these platforms often offer a drastically different look and feel, cross-platform applications deliver the same core functionality to the end user. Maintaining and evolving such applications currently requires replicating all the changes across all supported variants, a laborious and intellectually taxing enterprise. The state-of-the-practice automated source translation tools fall short, as they are incapable of handling the structural and idiomatic differences of the software frameworks driving major mobile platforms. In addition, popular mobile applications increasingly make use of distributed resources. Certain domains, including social networking, productivity enhancement, and gaming, require different application instances to continuously exchange information with each other. The current state of the art in supporting communication across heterogeneous mobile devices requires the programmer to write platform-specific, low-level API calls that are hard not only to develop but also to evolve and maintain. This thesis reports on the findings of two complementary research activities, conducted with the goal of facilitating the development and communication across heterogeneous mobile devices: (1) a programming model and runtime support for heterogeneous device-to-device communication across mobile applications; (2) a source code recommendation system that synthesizes code snippets from web-based programming resources, based on the functionality written for Android or iOS and vice versa. The conceptual and practical advancements of this research have potential to benefit fellow researchers as well as mobile software developers and users. / Master of Science

With the advent of exascale architectures maximizing performance while maintaining energy consumption within reasonable limits has become one of the most critical design constraints. This constraint is particularly significant in light of the power budget of 20 MWatts set by the U.S. Department of Energy for exascale supercomputing facilities. Therefore, understanding an application's characteristics, execution pattern, energy footprint, and the interactions of such aspects is critical to improving the application's performance as well as its utilization of the underlying resources. With conventional methods of analyzing performance and energy consumption trends scientists are forced to limit themselves to a manageable number of design parameters. While these modeling techniques have catered to the needs of current high-performance computing systems, the complexity and scale of exascale systems demands that large-scale design-space-exploration techniques are developed to enable comprehensive analysis and evaluations. In this dissertation we present research on performance and energy modeling of current high performance computing and future exascale systems. Our thesis is focused on the design space exploration of current and future architectures, in terms of their reconfigurability, application's sensitivity to hardware characteristics (e.g., system clock, memory bandwidth), application's execution patterns, application's communication behavior, and utilization of resources. Our research is aimed at understanding the methods by which we may maximize performance of exascale systems, minimize energy consumption, and understand the trade offs between the two. We use analytical, statistical, and machine-learning approaches to develop accurate, portable and scalable performance and energy models. We develop application and machine abstractions using Aspen (a domain specific language) to implement and evaluate our modeling techniques. As part of our research we develop and evaluate system-level performance and energy-consumption models that form part of an automated modeling framework, which analyzes application signatures to evaluate sensitivity of reconfigurable hardware components for candidate exascale proxy applications. We also develop statistical and machine-learning based models of the application's execution patterns on heterogeneous platforms. We also propose a communication and computation modeling and mapping framework for exascale proxy architectures and evaluate the framework for an exascale proxy application. These models serve as external and internal extensions to Aspen, which enable proxy exascale architecture implementations and thus facilitate design space exploration of exascale systems. / Ph. D.

The aim of this study was to investigate the effectiveness of a storybook retell technique to facilitate vocabulary acquisition in children educated in Māori immersion class settings. A second aim of the study was to explore the cultural responsiveness and pedagogical appropriateness of the intervention approach and the importance of relationship building (whakawhanaungatanga) to successful interventions. Nine children participated in the study. These children (aged between 5 and 8 years) were recruited from two Kura Kaupapa Māori settings in differing urban areas in New Zealand. The children entered the study on a rolling basis in groups of three. The first three participants to enter the study were recruited from the one classroom on the basis of their demonstrating specific language impairment (SLI). The second group of three participants attended a different classroom and these participants were recruited into the study as a result of identified delayed reading development (RD). The third group of three participants from a third classroom was selected as the participants exhibited typical spoken and written language development (TD). The intervention technique utilized in this study adopted a structured approach to teaching the meaning of pre selected vocabulary items that were embedded in class story books. Three different books were selected and each book was read by the teacher to the whole class three times during a one week period. The target vocabulary was highlighted each time it occurred in the story through the following techniques: an adult definition was given for the word, an antonym or synonym was given, and the meaning was acted out by the teacher or the picture detailing the meaning of the word in the book was highlighted. A single subject research design using pre-intervention, intervention and post intervention assessment probes for the target vocabulary items was employed to examine the effectiveness of the intervention in teaching the children the targeted vocabulary. Teacher interviews were also carried out to assess the appropriateness of the intervention in relation to the philosophy of the Kura Kaupapa and its pedagogical appropriateness and cultural responsiveness. The results suggested that the children in all three groups (SLI, RD and TD) made moderate gains in the acquisition of the target vocabulary supporting the hypothesis that targeting vocabulary in story book retelling at a whole class level will lead to acquisition of the vocabulary by the participants' exposed to the intervention. However, using a Two Standard Deviation method to evaluate the significance of each participant's change, the gains made for the RD and SLI participants were not significant. The TD participants did demonstrate a significant difference in the number of words correct. The teachers of the participants involved in the study reported positively on the effectiveness and appropriateness of the intervention for inclusion within the Kura Kaupapa and classroom programme. In particular, teachers' reported that as the intervention included each child in the class (as opposed to a withdrawal intervention model) the intervention was more appropriate for the philosophy of the Kura Kaupapa. The teachers' also reported the effectiveness of the intervention for the development of collaboration and relationship building between the teacher and researcher (a speech-language therapist. The data showed that the intervention investigated in this study was culturally responsive and pedagogically appropriate. It could be included as a component of the class programme as it was responsive to the philosophy of the Kura Kaupapa. The participants' did make moderate gains in the acquisition of the vocabulary (although not at a level to be considered significant for children with delayed development). Further research is necessary to explore the effectiveness of what may potentially be a useful intervention to enhance vocabulary development for children in Kura Kaupapa.

Dans de multiples domaines, un nombre grandissant d'applications interagissant avec des entités communicantes apparaissent dans l'environnement pour faciliter les activités quotidiennes~(domotique et télémédecine). Leur impact sur la vie de tous les jours des utilisateurs rend ces applications critiques: leur défaillance peut mettre en danger des personnes et leurs biens. Bien que l'impact de ces défaillances puisse être majeur, la sécurité est souvent considérée comme un problème secondaire dans le processus de développement et est traitée par des approches ad hoc.Cette thèse propose d'intégrer des aspects de sécurité dans le cycle de développement des systèmes d'informatique ubiquitaire. La sécurité est spécifiée à la conception grâce à des déclarations dédiées et de haut niveau. Ces déclarations sont utilisées pour générer un support de programmation afin de faciliter l'implémentation des mécanismes de sécurité, tout en séparant ces aspects de sécurité de la logique applicative. Notre approche se concentre sur le contrôle d'accès aux entités et la protection de la vie privée. Notre travail a été implémenté et fait levier sur une suite outillée existante couvrant le cycle de développement logiciel. / A growing number of environments is being populated with a range of networked devices. Applications leverage these devices to support everyday activities in a variety of areas (e.g., home automation and patient monitoring). As these devices and applications get woven into our everyday activities, they become critical: their failure can put people and assets at risk. Failures can be caused by malicious attacks and misbehaving applications. Although the impact of such situations can be major, security concerns are often considered a secondary issue in the development process, and treated with ad hoc approaches. This thesis proposes to address security concerns throughout the development lifecycle of a pervasive computing system. Security is addressed at design time thanks to dedicated, high-level declarations. These declarations are processed to implement security mechanisms, and to generate programming support to ease the development of the security logic, while keeping it separate from the application logic. Our approach is studied in the context of access control and privacy concerns. Our work has been implemented and leverages an existing software-design language and a suite of tools that covers the software development lifecycle.

Lors du développement des applications ubiquitaires, il est essentiel de définir des politiques de sécurité et de développerdes mécanismes de sécurité pour assurer la confidentialité et l’intégrité des applications. De nombreux langages de spécification de politiques se concentrent uniquement sur leur puissance d’expression. Les défis émergents dans les systèmes ubiquitaires ne peuvent pas être résolus par ces approches. Par exemple, la sensibilité au contexte est un élément central des systèmes ubiquitaires. Les approches existantes tiennent rarement compte des informations contextuelles dans leurs langages. Cette thèse propose une approche générative pour spécifier et implanter les politiques de sécurité dans les applications ubiquitaires. Pour définir une politique de sécurité, nous proposons un langage de spécification qui tient compte des informations contextuelles. Il permet aux développeurs de spécifier les règles de la politique et les entités requises (e.g. la description spatiale, les rôles, le contexte). Les politiques sont implémentés par des systèmes de réécriture, ce qui offre une grande puissance de vérification. Pour appliquer une politique, nous proposons une architecture qui intègre les concepts importants des politiques de sécurité (sujet, contexte, objet) dans des applications ubiquitaires. Pour mettre en oeuvre notre approche, nous avons enrichi une approche existante pour le développement des applications ubiquitaires. La spécification de la politique de sécurité et la description de l’application ubiquitaire enrichie sont utilisées pour générer un canevas de programmation qui facilite l’implémentation des mécanismes de sécurité, tout en séparant les aspects sécurités de la logique applicative. / When developing pervasive computing applications, it is critical to specify security policies and develop security mechanisms to ensure the confidentiality and integrity of the applications. Numerous policy specification languages only focus on their expressive power. The emerging challenges in pervasive computing systems can not be fulfilled by these approaches. For instance, context awareness is a central aspect of pervasive computing systems. Existing approaches rarely consider context information in their language.This thesis proposes a generative approach dedicated to specifying and enforcing security policies in pervasive computingapplications. To specify a policy, we propose a context-aware policy specification language which helps developers to specify policy rules and required entities (e.g. spatial description, roles, context information). Policies are implemented by term rewriting systems which offers great verification power. To enforce a policy, we propose an architecture that embeds important concepts of security policies (subject, object, security related context) into pervasive computing applications. To apply our approach, we enriched an existing approach which is dedicated to develop pervasive computing applications. Based on the policy specification and the enriched pervasive computing application descriptions, a dedicated programming framework is generated. This framework guides the implementation and raises the level of abstraction which can reduce the workloads of developers.

The domain-specific language allows for describing problems of a concrete domain, for which the language is created. This fact implies that a number of languages of this kind grows with a number of problem domains. The use of domain-specific languages brings a necessity to pretty-print these languages, where the concept of pretty-printing consists of code formatting and syntax highlighting. One of tools that allow for creating domain-specific languages is the Xtext framework, which offers only a limited range of tools that are able to define a configuration for pretty-printing. Moreover, these tools are hardly understandable because they are confusing and requires knowledge of Xtext's internals. Thus this thesis introduces a new way of pretty-printing domain-specific languages. The way is based on declarative definition of formatting rules. Furthermore, this thesis helps a user to create formatting rules by utilizing nontrivial heuristics.

In the scope of this thesis, we designed a language for programming education. At first, we described eight existing tools for learning programming and identified key features in the learning process. Second, we designed an educational domain-specific language Eddie. Eddie is suitable for teenagers and adults who want to learn programming. It uses a domain based on Karel the Robot language, where users can control a robot character in a two-dimensional grid. We implemented a prototype of Eddie using the MPS Language Workbench and its projectional editor. The Eddie language gradually introduces loops, conditionals, variables, functions, and objects. Eddie programs can be created, executed and visualized in the Eddie Studio IDE. Powered by TCPDF (www.tcpdf.org)

Malgré des progrès récents, développer une application d'informatique ubiquitaire reste un défi à cause d'un manque de canevas conceptuels et d'outils aidant au développement. Ce défi implique de prendre en charge des objets communicants hétérogènes, de surmonter la complexité des technologies de systèmes distribués, de définir l'architecture d'une application, et d'encoder cela dans un programme. De plus, tester des applications d'informatique ubiquitaire est problématique car cela implique d'acquérir, de tester et d'interfacer une variété d'entités logicielles et matérielles. Ce procédé peut rapidement devenir coûteux en argent et en temps lorsque l'environment ciblé implique de nombreuses entités.Cette thèse propose une méthodologie outillée pour développer et tester des applications d'informatique ubiquitaire. Notre méthodologie fournit tout d'abord le langage de conception DiaSpec. Ce langage permet de définir une taxonomie d'entités spécifiques à un domaine applicatif, s'abstrayant ainsi de leur hétérogénéité. Ce langage inclut également une couche permettant de définir l'architecture d'une application. Notre suite outillée fournit un compilateur qui, à partir de descriptions DiaSpec, génère un canevas de programmation guidant les phases d'implémentation et de test. Afin d'aider à la phase de test, nous proposons une approche de simulation et un outil intégré dans notre méthodologie outillée : l'outil DiaSim. Notre approche utilise le support de test généré par DiaSpec pour tester les applications de manière transparente dans un environnement physique simulé. La simulation d'une application est rendue graphiquement dans un outil de visualisation 2D.Nous avons combiné DiaSim avec un langage dédié permettant de décrire les phénomènes physiques en tant qu'équations différentielles. Cette combinaison nous permet une simulation réaliste des applications d'informatique ubiquitaire. DiaSim a été utilisé pour simuler des applications dans des domaines applicatifs variés. Notre approche de simulation a également été appliquée à un système avionique, démontrant la généralité de notre approche de simulation. / Despite much progress, developing a pervasive computing application remains a challenge because of a lack of conceptual frameworks and supporting tools. This challenge involves coping with heterogeneous devices, overcoming the intricacies of distributed systems technologies, working out an architecture for the application, and encoding it into a program. Moreover, testing pervasive computing applications is problematic because it requires acquiring, testing and interfacing a variety of software and hardware entities. This process can rapidly become costly and time-consuming when the target environment involves many entities.This thesis proposes a tool-based methodology for developing and testing pervasive computing applications. Our methodology first provides the DiaSpec design language that allows to define a taxonomy of area-specific building-blocks, abstracting over their heterogeneity. This language also includes a layer to define the architecture of an application. Our tool suite includes a compiler that takes DiaSpec design artifacts as input and generates a programming framework that supports the implementation and testing stages.To address the testing phase, we propose an approach and a tool integrated in our tool-based methodology, namely DiaSim. Our approach uses the testing support generated by DiaSpec to transparently test applications in a simulated physical environment. The simulation of an application is rendered graphically in a 2D visualization tool.We combined DiaSim with a domain-specific language for describing physical environment phenomena as differential equations, allowing a physically-accurate testing. DiaSim has been used to simulate various pervasive computing systems in different application areas. Our simulation approach has also been applied to an avionics system, which demonstrates the generality of our parameterized simulation approach.

Background: This study formed part of a larger longitudinal research study by Jordaan (2009), who tracked the development of language for academic purposes in grade 1- 3 English Additional Language (EAL) and English First Language (EFL) learners attending English only programmes in Gauteng over a period of three years. These learners attended schools in two different educational contexts where there is a marked heterogeneity in the linguistic backgrounds of both the learners and teachers investigated. Results from Jordaan’s (2009) study revealed that some EAL and EFL learners appeared to be slow in the development of their academic language abilities (as no progress was evident over the period of three years), relative to their peers, and thus these learners may have a language impairment. Purpose: This study investigated in detail, these “slow to learn” EAL and EFL learners in the foundation phase, in order to determine whether they have a language impairment and to determine how the language impairment manifests in these learners. Participants: Sixteen learners (5 EFL learners and 16 EAL learners) who demonstrated no improvement in their academic language abilities from grade one to grade two as determined by their performance on the Diagnostic Evaluation of Language Variation Criterion Referenced (DELV-CR) test were the participants of this study. Method: The participants were assessed on the Automated Working Memory Assessment (AWMA) test, a Non Word Repetition test (Dollaghan & Campbell, 1998), a Sentence Repetition test (Redmond, 2005) and the Gray Oral Reading Test (GORT-4). Educators were also asked to rate these learners’ oral language, written language and reading comprehension abilities on a scale of 0- 5. The research design utilized was a non experimental, descriptive quantitative design, involving both correlational and comparative components. The data obtained was then analysed using descriptive and inferential statistics. Pearson correlation coefficients were calculated to establish whether there was a relationship between the cognitive processing and the language proficiency measures as well as the teacher ratings in order to provide information regarding these tests as assessment tools for EAL learners as well as to further enhance the validity of this study. Independent sample t-tests were also conducted to determine whether there were any significant differences between the EFL and EAL learners’ performance in the two different educational contexts, so as to establish whether bilingual learners with language impairment are more severely impaired than monolingual learners with language impairment. Results: Based on the analysis of these learners’ performance on the DELV-CR test, results indicated that all sixteen participants presented with SLI and were not just “slow to learn”. The EAL-SLI learners in both contexts performed poorly on the reading comprehension test and were rated lower than their aged matched peers on the teacher rating scales. Furthermore, when comparing these EAL-SLI learners’ performance on the DELV-CR test to the performance of the EFL-SLI learners, the EAL-SLI learners as a group appeared to have performed more poorly than the EFL-SLI learners on all three subtests. As significant differences were found between the EAL and EFL learners’ performance on the DELV-CR test, the results suggested that bilingual learners with SLI, who acquire a second language sequentially, are more impaired than monolingual learners with SLI. The EAL-SLI learners also presented with visuo-spatial short term and working memory deficits and even though a large majority of the learners presented with verbal short term and working memory difficulties, not all the learners presented with cognitive processing difficulties. This finding has implications for the theories of SLI. However, the sentence repetition task was found to be a useful tool in differentiating between the “slow to learn” EAL learners and EAL-SLI learners and furthermore this test also positively correlated with various sections of the DELV-CR test which adds to the value of this test as an assessment tool in EAL learners. Positive correlations were also found between the teacher ratings of the EAL-SLI learners and the subtests of the DELV-CR test which indicates that teachers have the ability to correctly identify learners with language learning difficulties. Positive correlations were also found between the digit repetition subtest, the non word repetition test and the sentence repetition test which adds to the validity of this study. Conclusion: The results obtained from this study demonstrated that bilingual learners with SLI who acquire a second language sequentially are additionally disadvantaged compared to their EFL-SLI peers in the acquisition of certain aspects of academic language. Furthermore, although research has shown that cognitive processing measures are less biased in the assessment of linguistically diverse learners, results indicated that the DELV-CR test identified more accurately, learners with language impairment whereas the cognitive processing measures provided contradictory and biased results with the verbal working memory subtest over identifying learners “at risk” for language impairment. Finally, the use of sentence repetition tasks in the differentiation between “slow to learn” and language impaired EAL learners proves to be promising.