Model Driven software development has been considered to be a further software construction technology following object-oriented software development methods and with the potential to bring new breakthroughs in the research of software development. With deepening research, a growing number of Model Driven software development methods have been proposed. The model is now widely used in all aspects of software development. One key element determining progress in Model Driven software development research is how to better express and describe the models required for various software components. From a study of current Model Driven development technologies and methods, Domain-Specific Modelling is suggested in the thesis as a Model Driven method to better realise the potential of Model-Driven Software Development. Domain-specific modelling methods can be successfully applied to actual software development projects, which need a flexible and easy to extend, meta-modelling language to provide support. There is a particular requirement for modelling languages based on domain-specific modelling methods in Meta-modelling as most general modelling languages are not suitable. The thesis focuses on implementation of domain-specific modelling methods. The "domain" is stressed as a keystone of software design and development and this is what most differentiates the approach from general software development process and methods. Concerning the design of meta-modelling languages, the meta-modelling language based on XML is defined including its abstract syntax, concrete syntax and semantics. It can support description and construction of the domain meta-model and the domain application model. It can effectively realise visual descriptions, domain objects descriptions, relationships descriptions and rules relationships of domain model. In the area of supporting tools, a meta-meta model is given. The meta-meta model provides a group of general basic component meta-model elements together with the relationships between elements for the construction of the domain meta-model. It can support multi-view, multi-level description of the domain model. Developers or domain experts can complete the design and construction of the domain-specific meta-model and the domain application model in the integrated modelling environment. The thesis has laid the foundation necessary for research in descriptive languages through further study in key technologies of meta-modelling languages based on Model Driven development.

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Traditionally the dominant formalist school in mathematics has considered diagrams as merely heuristic tools. However, the last few years have seen a renewed interest in visualisation in mathematics and, in particular, in diagrammatic reasoning. This has resulteQ from the increasing capabilities of modern computers, the key role that design and modelling notations play in the development process of software systems, and the emergence of the first formal diagrammatic systems. Constraint diagrams are a diagrammatic notation for expressing constraints that can be used in conjunction with the Unified Modelling Language (UML) in object-oriented modelling. Recently, full formal semantics and sound and complete inference rules have been developed for Venn-Peirce diagrams and Euler circles. Spider diagrams emerged from work on constraint diagrams. They combine and extend Venn-Peirce diagrams and Euler circles to express constraints on sets and their relationships with other sets. The spider diagram system SDI developed in this thesis extends the second Venn-Peirce system that Shin investigated, Venn II, to give lower bounds for the cardinality of the sets represented by the diagrams. A sound and complete set of reasoning rules is given. The diagrammatic system SD2 extends SD 1 so that lower and upper bounds can be inferred for the cardinalities of the set represented by the diagrams. Soundness and completeness results are also given extending the proof strategies used in SD 1. The system SD2 is also shown to be syntactically rich enough to express the negation of any diagram. Finally, the ESD2 system incorporates syntactic elements from the spider diagram notation, so that information within a diagram can be expressed more compactly, and is proved equivalent to SD2. Two important innovations are introduced with respect to Venn I, Venn II, and Higraphs: two levels of syntax - abstract and concrete - and a proof of completeness that omits the use of maximal diagram used in these systems. This work will help to provide the necessary mathematical underpinning for the development of software tools to aid the reasoning process . and the development and formalisation of more expressive diagrammatic notations.

Discovering a word’s part of speech is an essential step in acquiring the grammar of a language. In this thesis we examine a variety of computational Bayesian models that use linguistic input available to children, in the form of transcribed child directed speech, to learn part of speech categories. Part of speech categories are characterised by contextual (distributional/syntactic) and word-internal (morphological) similarity. In this thesis, we assume language learners will be aware of these types of cues, and investigate exactly how they can make use of them. Firstly, we enrich the context of a standard model (the Bayesian Hidden Markov Model) by adding sentence type to the wider distributional context.We show that children are exposed to a much more diverse set of sentence types than evident in standard corpora used for NLP tasks, and previous work suggests that they are aware of the differences between sentence type as signalled by prosody and pragmatics. Sentence type affects local context distributions, and as such can be informative when relying on local context for categorisation. Adding sentence types to the model improves performance, depending on how it is integrated into our models. We discuss how to incorporate novel features into the model structure we use in a flexible manner, and present a second model type that learns to use sentence type as a distinguishing cue only when it is informative. Secondly, we add a model of morphological segmentation to the part of speech categorisation model, in order to model joint learning of syntactic categories and morphology. These two tasks are closely linked: categorising words into syntactic categories is aided by morphological information, and finding morphological patterns in words is aided by knowing the syntactic categories of those words. In our joint model, we find improved performance vis-a-vis single-task baselines, but the nature of the improvement depends on the morphological typology of the language being modelled. This is the first token-based joint model of unsupervised morphology and part of speech category learning of which we are aware.

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Engenharia Elétrica. / Made available in DSpace on 2012-10-22T14:42:14Z (GMT). No. of bitstreams: 1 229508.pdf: 8067955 bytes, checksum: 459c280bf1e5ed0933280e5060624868 (MD5) / Existe atualmente uma enorme variedade de equipamentos específicos cujo controlador microprocessado está embutido nos mesmos. Tais sistemas computacionais são embutidos como componentes dentro de um sistema maior. Na perspectiva da computação, tais sistemas são conhecidos como sistemas computacionais embutidos (embedded computer system), ou simplesmente sistemas embutidos (embedded systems). A grande maioria dos sistemas embutidos são programados e incluem componentes de hardware e de software. Para suportar o projeto de tais sistemas uma nova metodologia de projeto vem sendo desenvolvida denominada hardware/software co-design. Além do hardware/software co-design, é muito importante uma metodologia que leve a seleção do elemento de processamento ideal para a realização da tarefa específica do sistema embutido. O aumento de complexidade e variedade dos equipamentos com processador embutido gera a necessidade de uma abordagem interdisciplinar no processo de desenvolvimento desses equipamentos, envolvendo as áreas de engenharia de software, mecânica, elétrica e eletrônica. Neste sentido, está sendo especificada pela OMG uma linguagem de modelagem, denominada SysML (System Modelling Language), que pretende incluir em uma única especificação uma visão integrada do sistema, incluindo hardware, software e partes eletro-mecânicas. A dissertação faz um levantamento dos métodos e critérios empregados na seleção do processador a ser utilizado em um sistema embutido. As sugestões e métodos presentes na literatura são descritos, classificados e analisados. São modelados dois estudos de casos utilizando a linguagem de modelagem SysML. A partir da modelagem é realizada uma avaliação prática da atual proposta da linguagem SysML, no sentido de identificar suas capacidades e suas limitações na modelagem de sistemas embutidos, são analisados as possibilidades de extração das informações relevantes à seleção do processador embutido.

Model-driven development has been considered to be the hope of improving software productivity significantly. However, it has not been achieved even after many years of research and application. Models are only and still used at the analysis and design stage, furthermore, models gradually deviate from system implementation. The thesis integrates domain-specific modelling and web service techniques with model-driven development and proposes a unified approach, SODSMI (Service Oriented executable Domain-Specific Modelling and Implementation), to build the executable domain-specific model and to achieve the target of model-driven development. The approach is organised by domain space at architectural level which is the elementary unit of the domain-specific modelling and implementation framework. The research of SODSMI is made up of three main parts: Firstly, xDSM (eXecutable Domain-Specific Model) is proposed as the core construction for domain-specific modelling. Behaviour scenario is adopted to build the meta-modelling framework for xDSM. Secondly, XDML language (eXecutable Domain-specific Meta-modelling Language) is designed to describe the xDSM meta-model and its application model. Thirdly, DSMEI (Domain-Specific Model Execution Infrastructure) is designed as the execution environment for xDSM. Web services are adopted as the implementation entities mapping to core functions of xDSM so as to achieve the service-oriented domain-specific application. The thesis embodies the core value of model and provides a feasible approach to achieve real model-driven development from modelling to system implementation which makes domain-specific software development and reuse coming true.

With the availability of more and more cores within architectures the process of extracting implicit and explicit parallelism in applications to fully utilise these cores is becoming complex. Implicit parallelism extraction is performed through the inclusion of intelligent software and hardware sections of tool chains although these reach their theoretical limit rather quickly. Due to this the concept of a method of allowing explicit parallelism to be performed as fast a possible has been investigated. This method enables application developers to perform creation and synchronisation of parallel sections of an application at a finer-grained level than previously possible, resulting in smaller sections of code being executed in parallel while still reducing overall execution time. Alongside explicit parallelism, a concept of high level design of applications destined for multicore systems was also investigated. As systems are getting larger it is becoming more difficult to design and track the full life-cycle of development. One method used to ease this process is to use a graphical design process to visualise the high level designs of such systems. One drawback in graphical design is the explicit nature in which systems are required to be generated, this was investigated, and using concepts already in use in text based programming languages, the generation of platform-independent models which are able to be specialised to multiple hardware architectures was developed. The explicit parallelism was performed using hardware elements to perform thread management, this resulted in speed ups of over 13 times when compared to threading libraries executed in software on commercially available processors. This allowed applications with large data dependent sections to be parallelised in small sections within the code resulting in a decrease of overall execution time. The modelling concepts resulted in the saving of between 40-50% of the time and effort required to generate platform-specific models while only incurring an overhead of up to 15% the execution cycles of these models designed for specific architectures.

The aim of this research is to investigate parallel problem generation for structured optimization problems. The result of this research has produced a novel parallel model generator tool, namely the Parallel Structured Model Generator (PSMG). PSMG adopts the model syntax from SML to attain backward compatibility for the models already written in SML [1]. Unlike the proof-of-concept implementation for SML in [2], PSMG does not depend on AMPL [3]. In this thesis, we firstly explain what a structured problem is using concrete real-world problems modelled in SML. Presenting those example models allows us to exhibit PSMG’s modelling syntax and techniques in detail. PSMG provides an easy to use framework for modelling large scale nested structured problems including multi-stage stochastic problems. PSMG can be used for modelling linear programming (LP), quadratic programming (QP), and nonlinear programming (NLP) problems. The second part of this thesis describes considerable thoughts on logical calling sequence and dependencies in parallel operation and algorithms in PSMG. We explain the design concept for PSMG’s solver interface. The interface follows a solver driven work assignment approach that allows the solver to decide how to distribute problem parts to processors in order to obtain better data locality and load balancing for solving problems in parallel. PSMG adopts a delayed constraint expansion design. This allows the memory allocation for computed entities to only happen on a process when it is necessary. The computed entities can be the set expansions of the indexing expressions associated with the variable, parameter and constraint declarations, or temporary values used for set and parameter constructions. We also illustrate algorithms that are important for delivering efficient implementation of PSMG, such as routines for partitioning constraints according to blocks and automatic differentiation algorithms for evaluating Jacobian and Hessian matrices and their corresponding sparsity partterns. Furthermore, PSMG implements a generic solver interface which can be linked with different structure exploiting optimization solvers such as decomposition or interior point based solvers. The work required for linking with PSMG’s solver interface is also discussed. Finally, we evaluate PSMG’s run-time performance and memory usage by generating structured problems with various sizes. The results from both serial and parallel executions are discussed. The benchmark results show that PSMG achieve good parallel efficiency on up to 96 processes. PSMG distributes memory usage among parallel processors which enables the generation of problems that are too large to be processed on a single node due to memory restriction.

A UML é uma linguagem de modelagem largamente aceite entre profissionais da área de computação para a modelagem de sistemas simples e complexos. Tomando em consideração que os objetos de aprendizagem são entidades digitais, para o seu desenvolvimento, a utilização de metodologias torna-se um imperativo, se o objetivo for o de oferecer ao setor de educação ferramentas capazes de apoiar o processo de ensino aprendizagem. Os objetos de aprendizagem são ferramentas que podem contribuir para o aluno alcançar a aprendizagem significativa, se forem desenvolvidos dentro dos parâmetros considerados facilitadores da aprendizagem significativa. A presente pesquisa propõe uma metodologia alicerçada na aprendizagem significativa, denominada Metodologia de Modelagem de objetos de aprendizagem em UML (MOAUML) baseada em princípios de UML e de Design Instrucional, para a modelagem de objetos de aprendizagem, com vista a facilitar o desenvolvimento de objetos de aprendizagem que favoreçam a aprendizagem. Objetivando a validação da metodologia, equipes com diferentes perfis profissionais, modelaram 9 objetos de aprendizagem entre novos e legados. O resultado das modelagens mostrou que a utilização da MOAUML contribui para a facilidade na modelagem de objetos de aprendizagem, embora tenha sido mais fácil para equipes que já estavam familiarizadas com métodos de modelagem de software. / The UML is a widely accepted modelling language among computer specialists from simple to complex systems. In order to develop learning objects as digital entities, it is very important the utilization of any methodology aiming to deliver to the education sector capable tools for supporting the process of teaching learning. The learning objects are powerful tools that can contribute for student’s achievement of meaningful learning. This fact can be true only if the development procedures satisfied some characteristics considered facilitators of meaningful learning. This study proposes a methodology based on the meaningful learning, designated Modelling of Learning Objects Using UML (MOAUML) based on principles of UML and Instructional Design, for the modelling of learning objects targeting to facilitate the development of learning objects that promote meaningful learning. In order to validate the MOAUML, different teams with distinguish profiles, were modelled 9 learning objects among news and legacies. The results of that process disclosed that the use of MOAUML contributes to the ease of modelling learning objects, although it has been easier for teams that were already familiar with software modelling processes.

Tese de Doutoramento. Engenharia Industrial e Gestão. Faculdade de Engenharia. Universidade do Porto. 2012