A software development framework for context-aware systems

The beginning of the new century has been characterised by the miniaturisation and accessibility of electronics, which has enabled its widespread usage around the world. This technological background is progressively materialising the future of the remainder of the century, where industry-based societies have been moving towards information-based societies. Information from users and their environment is now pervasively available, and many new research areas have born in order to shape the potential of such advancements. Particularly, context-aware computing is at the core of many areas such as Intelligent Environments, Ambient Intelligence, Ambient Assisted Living or Pervasive Computing. Embedding contextual awareness into computers promises a fundamental enhancement in the interaction between computers and humans. While traditional computers require explicit commands in order to operate, contextually aware computers could also use information from the background and the users to provide services according to the situation. But embedding this contextual awareness has many unresolved challenges. The area of context-aware computing has attracted the interest of many researchers that have presented different approaches to solve particular aspects on the implementation of this technology. The great corpus of research in this direction indicates that context-aware systems have different requirements than those of traditional computing. Approaches for developing context-aware systems are typically scattered or do not present compatibility with other approaches. Existing techniques for creating context-aware systems also do not focus on covering all the different stages of a typical software development life-cycle. The contribution of this thesis is towards the foundation layers of a more holistic approach, that tries to facilitate further research on the best techniques for developing these kinds of systems. The approach presents a framework to support the development not only with methodologies, but with open-source tools that facilitate the implementation of context-aware systems in mobile and stationary platforms

Continuous Rationale Management

Continuous Software Engineering (CSE) is a software life cycle model open to frequent changes in requirements or technology. During CSE, software developers continuously make decisions on the requirements and design of the software or the development process. They establish essential decision knowledge, which they need to document and share so that it supports the evolution and changes of the software. The management of decision knowledge is called rationale management. Rationale management provides an opportunity to support the change process during CSE. However, rationale management is not well integrated into CSE. The overall goal of this dissertation is to provide workflows and tool support for continuous rationale management. The dissertation contributes an interview study with practitioners from the industry, which investigates rationale management problems, current practices, and features to support continuous rationale management beneficial for practitioners. Problems of rationale management in practice are threefold: First, documenting decision knowledge is intrusive in the development process and an additional effort. Second, the high amount of distributed decision knowledge documentation is difficult to access and use. Third, the documented knowledge can be of low quality, e.g., outdated, which impedes its use. The dissertation contributes a systematic mapping study on recommendation and classification approaches to treat the rationale management problems. The major contribution of this dissertation is a validated approach for continuous rationale management consisting of the ConRat life cycle model extension and the comprehensive ConDec tool support. To reduce intrusiveness and additional effort, ConRat integrates rationale management activities into existing workflows, such as requirements elicitation, development, and meetings. ConDec integrates into standard development tools instead of providing a separate tool. ConDec enables lightweight capturing and use of decision knowledge from various artifacts and reduces the developers' effort through automatic text classification, recommendation, and nudging mechanisms for rationale management. To enable access and use of distributed decision knowledge documentation, ConRat defines a knowledge model of decision knowledge and other artifacts. ConDec instantiates the model as a knowledge graph and offers interactive knowledge views with useful tailoring, e.g., transitive linking. To operationalize high quality, ConRat introduces the rationale backlog, the definition of done for knowledge documentation, and metrics for intra-rationale completeness and decision coverage of requirements and code. ConDec implements these agile concepts for rationale management and a knowledge dashboard. ConDec also supports consistent changes through change impact analysis. The dissertation shows the feasibility, effectiveness, and user acceptance of ConRat and ConDec in six case study projects in an industrial setting. Besides, it comprehensively analyses the rationale documentation created in the projects. The validation indicates that ConRat and ConDec benefit CSE projects. Based on the dissertation, continuous rationale management should become a standard part of CSE, like automated testing or continuous integration

Smart contract and web dapp for tracing sustainability indicators in the textile and clothing value chain

Mestrado em Engenharia Informática na Escola Superior de Tecnologia e Gestão do Instituto Politécnico de Viana do CasteloNa sociedade atual, o têxtil e vestuário é um dos maiores setores de mercado do mundo. O rápido crescimento desta indústria está a ter impactos sem precedentes na sustentabilidade do planeta, respondendo por consequências negativas ambientais, sociais e de saúde. As tendências da fast-fashion, juntamente com a falta de transparência na cadeia de valor têxtil global, somam-se a cenários desfavoráveis para o mundo, à medida que os níveis crescentes de poluição e consumo de recursos dentro da cadeia de valor atingem máximos históricos a cada ano que passa. O ciclo de vida de uma peça de roupa precisa de se adaptar a um modelo económico regenerativo em vez de linear, que acaba no equivalente a um caminhão de lixo de produtos têxteis sendo descartado num aterro sanitário a cada segundo [1]. Não só as indústrias precisam de reformular os seus processos para circularizar as suas cadeias de valor e promover ações sustentáveis, mas também os consumidores precisam de participar do processo de manter os produtos no círculo da cadeia de valor, pois cabe a eles decidir o destino final de um produto vestuário aquando o seu fim da vida útil. Com estas questões em mente, esta dissertação visa desenvolver duas soluções que possam mitigar os problemas a cima mencionados e promover ações sustentáveis rumo a uma economia circular na cadeia de valor do têxtil e vestuário. Uma solução business-to-business baseada em smart contracts do Hyperledger Fabric para gerir a cadeia de valor do têxtil e vestuário com funcionalidade de rastreabilidade foi desenvolvida como prova de conceito para apoiar as reivindicações de sustentabilidade dos participantes na cadeia de valor, da fibra à peça final de vestuário. A actual funcionabilidade de rastreabilidade desenvolvida no smart contract fornece aos operadores da cadeia de valor a capacidade de rastrear um lote até à sua origem, contudo, também limita a escalabilidade devido ao aumento exponencial do tamanho do bloco, especialmente se considerarmos uma cadeia de valor circular. Para os consumidores, foi proposta uma aplicação descentralizada business-to-consumer-to-consumer com elementos de eco-gamificação para promover o envolvimento e motivação do utilizador para a realização de tarefas que contribuam para a adoção de uma economia circular na cadeia de valor do têxtil e vestuário. Após testar a usabilidade da aplicação com o questionário AttrakDiff, concluiu-se que o sistema precisa de focar a sua usabilidade em prol de um produto orientado à tarefa em vez da orientação pessoal atual da aplicação a fim de promover ações que contribuam para a economia circular da cadeia de valor do têxtil e vestuário.In today’s society, Textile and Clothing (T&C) is one of the biggest market sectors world wide.The sheer size and fast growth of this industry is having unprecedented impacts on sustainability, accounting for negative environmental, social and health consequences. The fast-fashion trends along side the lack of transparency in the global T&C value chain add up to unfavorable scenarios for the world as the increas- ing levels of pollution and resource consumption within the value chain reach historic highs with every year that passes. The lifecycle of a clothing item needs to adapt to a regenerative economic model instead of a linear one that ends up in the equivalent of a garbage truck full of textiles being disposed into a landfill every second [1]. Not only do the industries need to revamp their processes to circularize their value chains and promote sustainable actions, but the consumers also need to partake in the process of keeping the products in the value chain loop as it is up to them to make the final decision upon the end-of-life of an item of clothing. With these issues in mind,this dissertation aims to develop two solutions that can mitigate the aforementioned problems and promote sustainable actions towards a circular economy in the T&C value chain. A Proof-of-Concept (PoC) Business-to-Business (B2B) T&C value chainmanagement smart contract solution builton Hyperledger Fabric with traceability features was developed to support the sustainability claims of participants in the value chain, from fiber to garment. The current traceability feature developed into the smart contract provides value chain operators the capabilities to trace a batch back to its origin, however, it also constraints scalability due to the exponential in crease in block size specially if considering a circular value chain. For the consumers, a Business-to-Consumer-to-Consumer (B2C2C) Decentralized Application (DApp) was proposed with eco-gamification elements fo rpromoting the user’s engagement and motivation to complete tasks that contribute for the adoption of a circular economy in the T&C value chain. After testing the consumer DApp’s usability with the AttrakDiff survey, it was concluded that the system needs to focus it susability towards a task-oriented product instead of the current self-oriented results in order to promote actions that contribute to the circular economy of the T&C value chain

Embedded System Design

A unique feature of this open access textbook is to provide a comprehensive introduction to the fundamental knowledge in embedded systems, with applications in cyber-physical systems and the Internet of things. It starts with an introduction to the field and a survey of specification models and languages for embedded and cyber-physical systems. It provides a brief overview of hardware devices used for such systems and presents the essentials of system software for embedded systems, including real-time operating systems. The author also discusses evaluation and validation techniques for embedded systems and provides an overview of techniques for mapping applications to execution platforms, including multi-core platforms. Embedded systems have to operate under tight constraints and, hence, the book also contains a selected set of optimization techniques, including software optimization techniques. The book closes with a brief survey on testing. This fourth edition has been updated and revised to reflect new trends and technologies, such as the importance of cyber-physical systems (CPS) and the Internet of things (IoT), the evolution of single-core processors to multi-core processors, and the increased importance of energy efficiency and thermal issues

Towards A Formal And Scalable Approach For Quantifying Software Reliability At Early Development Stages

Problems which originate in early development stages can have a lasting influence on the reliability, safety, and cost of a software system. The requirements document, which is usually available at the requirements analysis stage, must be correct, unambiguous, and complete if the rest of the development effort is to succeed. The ability to identify faults in requirements and predict the reliability of a software system early in its development can help organizations make informative decisions about corrective actions and improve the system's quality in a cost-effective manner. A review of the literature reveals that existing approaches are unsuited to provide trustworthy reliability prediction either due to the ignorance of the requirements documents, or because of the informal and fairly sketchy way in detecting faults in requirements. This study explores the use of a preselected software reliability measurement for early software faults detection and reliability prediction. This measurement, originally a black-box testing technique, was broadly recognized for its ability to detect incomplete and ambiguous requirements, although no information was found in the literature about how to take advantage of its power. This study mathematically formalized the measurement to enhance its rigidity, repeatability and scalability and further extended it as an effective requirements faults detection technique. An automation-oriented algorithm was developed for quantifying the impact of the detected requirements faults on software reliability. The feasibility and scalability of the proposed approach for early faults detection and reliability prediction were examined using two real applications. The results clearly confirmed its feasibility and usefulness, particularly when no failure data is available and other methods are not applicable. The scalability barriers were also spotted in the approach. An empirical study was thus conducted to gain insight into the nature of the technical barriers. As an attempt to overcome the barrier, a set of rules was proposed based on the observed patterns. Finally, a preliminarily controlled experiment was conducted to evaluate the usability of the proposed rules. This study will enable software project stakeholders to effectively detect requirements faults and assess the quality of requirements early in development, and ultimately lead to improved software reliability if the identified faults are removed in time. Software project practitioners, regulators, and policy makers involved in the certification of software systems can benefit most from the techniques proposed in this study

Embedded System Design

A unique feature of this open access textbook is to provide a comprehensive introduction to the fundamental knowledge in embedded systems, with applications in cyber-physical systems and the Internet of things. It starts with an introduction to the field and a survey of specification models and languages for embedded and cyber-physical systems. It provides a brief overview of hardware devices used for such systems and presents the essentials of system software for embedded systems, including real-time operating systems. The author also discusses evaluation and validation techniques for embedded systems and provides an overview of techniques for mapping applications to execution platforms, including multi-core platforms. Embedded systems have to operate under tight constraints and, hence, the book also contains a selected set of optimization techniques, including software optimization techniques. The book closes with a brief survey on testing. This fourth edition has been updated and revised to reflect new trends and technologies, such as the importance of cyber-physical systems (CPS) and the Internet of things (IoT), the evolution of single-core processors to multi-core processors, and the increased importance of energy efficiency and thermal issues