A Component Architecture for High-Performance Scientific Computing

The Common Component Architecture (CCA) provides a means for software developers to manage the complexity of large-scale scientific simulations and to move toward a plug-and-play environment for high-performance computing. In the scientific computing context, component models also promote collaboration using independently developed software, thereby allowing particular individuals or groups to focus on the aspects of greatest interest to them. The CCA supports parallel and distributed computing as well as local high-performance connections between components in a language-independent manner. The design places minimal requirements on components and thus facilitates the integration of existing code into the CCA environment. The CCA model imposes minimal overhead to minimize the impact on application performance. The focus on high performance distinguishes the CCA from most other component models. The CCA is being applied within an increasing range of disciplines, including combustion research, global climate simulation, and computational chemistry

Pattern operators for grid

The definition and programming of distributed applications has become a major research issue due to the increasing availability of (large scale) distributed platforms and the requirements posed by the economical globalization. However, such a task requires a huge effort due to the complexity of the distributed environments: large amount of users may communicate and share information across different authority domains; moreover, the “execution environment” or “computations” are dynamic since the number of users and the computational infrastructure change in time. Grid environments, in particular, promise to be an answer to deal with such complexity, by providing high performance execution support to large amount of users, and resource sharing across different organizations. Nevertheless, programming in Grid environments is still a difficult task. There is a lack of high level programming paradigms and support tools that may guide the application developer and allow reusability of state-of-the-art solutions. Specifically, the main goal of the work presented in this thesis is to contribute to the simplification of the development cycle of applications for Grid environments by bringing structure and flexibility to three stages of that cycle through a commonmodel. The stages are: the design phase, the execution phase, and the reconfiguration phase. The common model is based on the manipulation of patterns through pattern operators, and the division of both patterns and operators into two categories, namely structural and behavioural. Moreover, both structural and behavioural patterns are first class entities at each of the aforesaid stages. At the design phase, patterns can be manipulated like other first class entities such as components. This allows a more structured way to build applications by reusing and composing state-of-the-art patterns. At the execution phase, patterns are units of execution control: it is possible, for example, to start or stop and to resume the execution of a pattern as a single entity. At the reconfiguration phase, patterns can also be manipulated as single entities with the additional advantage that it is possible to perform a structural reconfiguration while keeping some of the behavioural constraints, and vice-versa. For example, it is possible to replace a behavioural pattern, which was applied to some structural pattern, with another behavioural pattern. In this thesis, besides the proposal of the methodology for distributed application development, as sketched above, a definition of a relevant set of pattern operators was made. The methodology and the expressivity of the pattern operators were assessed through the development of several representative distributed applications. To support this validation, a prototype was designed and implemented, encompassing some relevant patterns and a significant part of the patterns operators defined. This prototype was based in the Triana environment; Triana supports the development and deployment of distributed applications in the Grid through a dataflow-based programming model. Additionally, this thesis also presents the analysis of a mapping of some operators for execution control onto the Distributed Resource Management Application API (DRMAA). This assessment confirmed the suitability of the proposed model, as well as the generality and flexibility of the defined pattern operatorsDepartamento de Informática and Faculdade de Ciências e Tecnologia of the Universidade Nova de Lisboa; Centro de Informática e Tecnologias da Informação of the FCT/UNL; Reitoria da Universidade Nova de Lisboa; Distributed Collaborative Computing Group, Cardiff University, United Kingdom; Fundação para a Ciência e Tecnologia; Instituto de Cooperação Científica e Tecnológica Internacional; French Embassy in Portugal; European Union Commission through the Agentcities.NET and Coordina projects; and the European Science Foundation, EURESCO

Adaptive networks for robotics and the emergence of reward anticipatory circuits

Currently the central challenge facing evolutionary robotics is to determine how best to extend the range and complexity of behaviour supported by evolved neural systems. Implicit in the work described in this thesis is the idea that this might best be achieved through devising neural circuits (tractable to evolutionary exploration) that exhibit complementary functional characteristics. We concentrate on two problem domains; locomotion and sequence learning. For locomotion we compare the use of GasNets and other adaptive networks. For sequence learning we introduce a novel connectionist model inspired by the role of dopamine in the basal ganglia (commonly interpreted as a form of reinforcement learning). This connectionist approach relies upon a new neuron model inspired by notions of energy efficient signalling. Two reward adaptive circuit variants were investigated. These were applied respectively to two learning problems; where action sequences are required to take place in a strict order, and secondly, where action sequences are robust to intermediate arbitrary states. We conclude the thesis by proposing a formal model of functional integration, encompassing locomotion and sequence learning, extending ideas proposed by W. Ross Ashby. A general model of the adaptive replicator is presented, incoporating subsystems that are tuned to continuous variation and discrete or conditional events. Comparisons are made with Ross W. Ashby's model of ultrastability and his ideas on adaptive behaviour. This model is intended to support our assertion that, GasNets (and similar networks) and reward adaptive circuits of the type presented here, are intrinsically complementary. In conclusion we present some ideas on how the co-evolution of GasNet and reward adaptive circuits might lead us to significant improvements in the synthesis of agents capable of exhibiting complex adaptive behaviour

Pattern Operators for Grid Environments

The definition and programming of distributed applications has become a major research issue due to the increasing availability of (large scale) distributed platforms and the requirements posed by the economical globalization. However, such a task requires a huge effort due to the complexity of the distributed environments: large amount of users may communicate and share information across different authority domains; moreover, the “execution environment” or “computations” are dynamic since the number of users and the computational infrastructure change in time. Grid environments, in particular, promise to be an answer to deal with such complexity, by providing high performance execution support to large amount of users, and resource sharing across different organizations. Nevertheless, programming in Grid environments is still a difficult task. There is a lack of high level programming paradigms and support tools that may guide the application developer and allow reusability of state-of-the-art solutions. Specifically, the main goal of the work presented in this thesis is to contribute to the simplification of the development cycle of applications for Grid environments by bringing structure and flexibility to three stages of that cycle through a commonmodel. The stages are: the design phase, the execution phase, and the reconfiguration phase. The common model is based on the manipulation of patterns through pattern operators, and the division of both patterns and operators into two categories, namely structural and behavioural. Moreover, both structural and behavioural patterns are first class entities at each of the aforesaid stages. At the design phase, patterns can be manipulated like other first class entities such as components. This allows a more structured way to build applications by reusing and composing state-of-the-art patterns. At the execution phase, patterns are units of execution control: it is possible, for example, to start or stop and to resume the execution of a pattern as a single entity. At the reconfiguration phase, patterns can also be manipulated as single entities with the additional advantage that it is possible to perform a structural reconfiguration while keeping some of the behavioural constraints, and vice-versa. For example, it is possible to replace a behavioural pattern, which was applied to some structural pattern, with another behavioural pattern. In this thesis, besides the proposal of the methodology for distributed application development, as sketched above, a definition of a relevant set of pattern operators was made. The methodology and the expressivity of the pattern operators were assessed through the development of several representative distributed applications. To support this validation, a prototype was designed and implemented, encompassing some relevant patterns and a significant part of the patterns operators defined. This prototype was based in the Triana environment; Triana supports the development and deployment of distributed applications in the Grid through a dataflow-based programming model. Additionally, this thesis also presents the analysis of a mapping of some operators for execution control onto the Distributed Resource Management Application API (DRMAA). This assessment confirmed the suitability of the proposed model, as well as the generality and flexibility of the defined pattern operatorsDepartamento de Informática and Faculdade de Ciências e Tecnologia of the Universidade Nova de Lisboa; Centro de Informática e Tecnologias da Informação of the FCT/UNL; Reitoria da Universidade Nova de Lisboa; Distributed Collaborative Computing Group, Cardiff University, United Kingdom; Fundação para a Ciência e Tecnologia; Instituto de Cooperação Científica e Tecnológica Internacional; French Embassy in Portugal; European Union Commission through the Agentcities.NET and Coordina projects; and the European Science Foundation, EURESCO

Une approche basée sur les modèles pour le développement d'applications de simulation numérique haute-performance

Le développement et la maintenance d'applications de simulation numérique haute-performance sont des activités complexes. Cette complexité découle notamment du couplage fort existant entre logiciel et matériel ainsi que du manque d'accessibilité des solutions de programmation actuelles et du mélange des préoccupations qu'elles induisent. Dans cette thèse nous proposons une approche pour le développement d'applications de simulation numérique haute-performance qui repose sur l'ingénierie des modèles. Afin à la fois de réduire les couts et les délais de portage sur de nouvelles architectures matérielles mais également de concentrer les efforts sur des interventions à plus haute valeur ajoutée, cette approche nommée MDE4HPC, définit un langage de modélisation dédié. Ce dernier permet aux numériciens de décrire la résolution de leurs modèles théoriques dans un langage qui d'une part leur est familier et d'autre part est indépendant d'une quelconque architecture matérielle. Les différentes préoccupations logicielles sont séparées grâce à l'utilisation de plusieurs modèles et de plusieurs points de vue sur ces modèles. En fonction des plateformes d'exécution disponibles, ces modèles abstraits sont alors traduits en implémentations exécutables grâce à des transformations de modèles mutualisables entre les divers projets de développement. Afin de valider notre approche nous avons développé un prototype nommé ArchiMDE. Grâce à cet outil nous avons développé plusieurs applications de simulation numérique pour valider les choix de conception réalisés pour le langage de modélisation.The development and maintenance of high-performance scientific computing software is a complex task. This complexity results from the fact that software and hardware are tightly coupled. Furthermore current parallel programming approaches lack of accessibility and lead to a mixing of concerns within the source code. In this thesis we define an approach for the development of high-performance scientific computing software which relies on model-driven engineering. In order to reduce both duration and cost of migration phases toward new hardware architectures and also to focus on tasks with higher added value this approach called MDE4HPC defines a domain-specific modeling language. This language enables applied mathematicians to describe their numerical model in a both user-friendly and hardware independent way. The different concerns are separated thanks to the use of several models as well as several modeling viewpoints on these models. Depending on the targeted execution platforms, these abstract models are translated into executable implementations with model transformations that can be shared among several software developments. To evaluate the effectiveness of this approach we developed a tool called ArchiMDE. Using this tool we developed different numerical simulation software to validate the design choices made regarding the modeling language

Semantic discovery and reuse of business process patterns

Patterns currently play an important role in modern information systems (IS) development and their use has mainly been restricted to the design and implementation phases of the development lifecycle. Given the increasing significance of business modelling in IS development, patterns have the potential of providing a viable solution for promoting reusability of recurrent generalized models in the very early stages of development. As a statement of research-in-progress this paper focuses on business process patterns and proposes an initial methodological framework for the discovery and reuse of business process patterns within the IS development lifecycle. The framework borrows ideas from the domain engineering literature and proposes the use of semantics to drive both the discovery of patterns as well as their reuse

Beyond the Electronic Connection: The Technologically Manufactured Cyber-Human and Its Physical Human Counterpart in Performance: A Theory Related to Convergence Identities

This thesis is an investigation of the complex processes and relationships between the physical human performer and the technologically manufactured cyber-human counterpart. I acted as both researcher and the physical human performer, deeply engaged in the moment-to-moment creation of events unfolding within a shared virtual reality environment. As the primary instigator and activator of the cyber-human partner, I maintained a balance between the live and technological performance elements, prioritizing the production of content and meaning. By way of using practice as research, this thesis argues that in considering interactions between cyber-human and human performers, it is crucial to move beyond discussions of technology when considering interactions between cyber-humans and human performers to an analysis of emotional content, the powers of poetic imagery, the trust that is developed through sensory perception and the evocation of complex relationships. A theoretical model is constructed to describe the relationship between a cyber-human and a human performer in the five works created specifically for this thesis, which is not substantially different from that between human performers. Technological exploration allows for the observation and analysis of various relationships, furthering an expanded understanding of ‘movement as content’ beyond the electronic connection. Each of the works created for this research used new and innovative technologies, including virtual reality, multiple interactive systems, six generations of wearable computers, motion capture technology, high-end digital lighting projectors, various projection screens, smart electronically charged fabrics, multiple sensory sensitive devices and intelligent sensory charged alternative performance spaces. They were most often collaboratively created in order to augment all aspects of the performance and create the sense of community found in digital live dance performances/events. These works are identified as one continuous line of energy and discovery, each representing a slight variation on the premise that a working, caring, visceral and poetic content occurs beyond the technological tools. Consequently, a shift in the physical human’s psyche overwhelms the act of performance. Scholarship and reflection on the works have been integral to my creative process throughout. The goals of this thesis, the works created and the resulting methodologies are to investigate performance to heighten the multiple ways we experience and interact with the world. This maximizes connection and results in a highly interactive, improvisational, dynamic, non-linear, immediate, accessible, agential, reciprocal, emotional, visceral and transformative experience without boundaries between the virtual and physical for physical humans, cyborgs and cyber-humans alike.College of Fine Arts at the University of Texas at Austin, Department of Theatre & Dance at the University of Texas at Austi

The Value of Everything: Ranking and Association with Encyclopedic Knowledge

This dissertation describes WikiRank, an unsupervised method of assigning relative values to elements of a broad coverage encyclopedic information source in order to identify those entries that may be relevant to a given piece of text. The valuation given to an entry is based not on textual similarity but instead on the links that associate entries, and an estimation of the expected frequency of visitation that would be given to each entry based on those associations in context. This estimation of relative frequency of visitation is embodied in modifications to the random walk interpretation of the PageRank algorithm. WikiRank is an effective algorithm to support natural language processing applications. It is shown to exceed the performance of previous machine learning algorithms for the task of automatic topic identification, providing results comparable to that of human annotators. Second, WikiRank is found useful for the task of recognizing text-based paraphrases on a semantic level, by comparing the distribution of attention generated by two pieces of text using the encyclopedic resource as a common reference. Finally, WikiRank is shown to have the ability to use its base of encyclopedic knowledge to recognize terms from different ontologies as describing the same thing, and thus allowing for the automatic generation of mapping links between ontologies. The conclusion of this thesis is that the "knowledge access heuristic" is valuable and that a ranking process based on a large encyclopedic resource can form the basis for an extendable general purpose mechanism capable of identifying relevant concepts by association, which in turn can be effectively utilized for enumeration and comparison at a semantic level

Characterizing Middle School Students’ Physical Literacy: A Sequential Mixed Methods Study

The purpose of this dissertation study was (a) to characterize middle school students’ levels of physical literacy (PL) and PL domains by gender, grade, socioeconomic status (SES), weight status, race, and ethnicity; and (b) to capture PL trajectory change as a result of receiving a theory-informed pedagogical workshop. Participants (N = 350) in sixth and seventh grades were recruited from a public middle school located in a southeastern U.S. state. These students completed the second version of the Canadian Assessment of Physical Literacy (CAPL-2). A subsample (n = 49) received a pedagogical workshop (four sessions over eight weeks), participated in two focus-group interviews (pre and post workshop), and completed the CAPL-2 upon intervention. Demographic data were collected using questionnaire, while weight and height were collected using stadiometer and weight scale to calculate body mass index (BMI) percentile. I found (a) gender-based differences in PL (favor boys; d = 0.29), cognitive (favor girls; d = 0.35), physical (favor boys; d = 0.59), and affective domains (favor boys; d = 0.32); (b) grade-based differences in cognitive (favor seventh grade; d = 0.32) and physical (favor sixth grade; d = 0.33) domains; (c) SES-based differences in PL (d = 0.52), cognitive (d = 0.33), and behavioral (d = 0.63) domains, all favoring high SES group; (d) BMI-based differences in PL (d = 0.68), physical (d = 0.90), and affective (d = 0.40) domains, all favoring normal BMI group; and (e) race-based differences in cognitive (d = 0.44) and behavioral (d = 0.78) domains all favoring White. The subsample, after workshop intervention, showed improvement in PL, and cognitive and affective domains (d: 0.29 – 0.42) as assessed by CAPL-2. Interview data delineated a positive trend of PL change by virtue of physical activity type and intensity, perceived motives, and barriers of physical activity participation. The findings of this study bear significant implications for future PL interventions. PL is a dynamic state that can be improved across populations through purposeful PE curriculum and instruction