Component-based applications require runtime support to be able to guarantee non-functional properties. This report proposes an architecture for a real-time-capable, component-based runtime environment, which allows to separate non-functional and functional concerns in component-based software development. The architecture is presented with particular focus on three key issues: the conceptual architecture, an approach including implementation issues for splitting the runtime environment into a real-time-capable and a real-time-incapable part, and details of contract negotiation. The latter includes selecting component implementations for instantiantion based on their non-functional properties.

Development of software for embedded real-time systems poses severalchallenges. Hard and soft constraints on timing, and usually considerableresource limitations, put important constraints on the development. Thetraditional way of coping with these issues is to produce a fully static design,i.e. one that is fully fixed already during design time.Current trends in the area of embedded systems, including the emergingopenness in these types of systems, are providing new challenges for theirdesigners – e.g. integration of new software during runtime, software upgradeor run-time adaptation of application behavior to facilitate better performancecombined with more ecient resource usage. One way to reach these goals is tobuild self-configurable systems, i.e. systems that can resolve such issues withouthuman intervention. Such mechanisms may be used to promote increasedsystem openness.This thesis covers some of the challenges involved in that development.An overview of the current situation is given, with a extensive review ofdi erent concepts that are applicable to the problem, including adaptivitymechanisms (incluing QoS and load balancing), middleware and relevantdesign approaches (component-based, model-based and architectural design).A middleware is a software layer that can be used in distributed systems,with the purpose of abstracting away distribution, and possibly other aspects,for the application developers. The DySCAS project had as a major goaldevelopment of middleware for self-configurable systems in the automotivesector. Such development is complicated by the special requirements thatapply to these platforms.Work on the implementation of an adaptive middleware, DyLite, providingself-configurability to small-scale microcontrollers, is described andcovered in detail. DyLite is a partial implementation of the concepts developedin DySCAS.Another area given significant focus is formal modeling of QoS andresource management. Currently, applications in these types of systems arenot given a fully formal definition, at least not one also covering real-timeaspects. Using formal modeling would extend the possibilities for verificationof not only system functionality, but also of resource usage, timing and otherextra-functional requirements. This thesis includes a proposal of a formalismto be used for these purposes.Several challenges in providing methodology and tools that are usablein a production development still remain. Several key issues in this areaare described, e.g. version/configuration management, access control, andintegration between di erent tools, together with proposals for future workin the other areas covered by the thesis. / Utveckling av mjukvara för inbyggda realtidssystem innebär flera utmaningar.Hårda och mjuka tidskrav, och vanligtvis betydande resursbegränsningar,innebär viktiga inskränkningar på utvecklingen. Det traditionellasättet att hantera dessa utmaningar är att skapa en helt statisk design, d.v.s.en som är helt fix efter utvecklingsskedet.Dagens trender i området inbyggda system, inräknat trenden mot systemöppenhet,skapar nya utmaningar för systemens konstruktörer – exempelvisintegration av ny mjukvara under körskedet, uppgradering av mjukvaraeller anpassning av applikationsbeteende under körskedet för att nå bättreprestanda kombinerat med e ektivare resursutnyttjande. Ett sätt att nå dessamål är att bygga självkonfigurerande system, d.v.s. system som kan lösa sådanautmaningar utan mänsklig inblandning. Sådana mekanismer kan användas föratt öka systemens öppenhet.Denna avhandling täcker några av utmaningarna i denna utveckling. Enöversikt av den nuvarande situationen ges, med en omfattande genomgångav olika koncept som är relevanta för problemet, inklusive anpassningsmekanismer(inklusive QoS och lastbalansering), mellanprogramvara och relevantadesignansatser (komponentbaserad, modellbaserad och arkitekturell design).En mellanprogramvara är ett mjukvarulager som kan användas i distribueradesystem, med syfte att abstrahera bort fördelning av en applikation överett nätverk, och möjligtvis även andra aspekter, för applikationsutvecklarna.DySCAS-projektet hade utveckling av mellanprogramvara för självkonfigurerbarasystem i bilbranschen som ett huvudmål. Sådan utveckling försvåras avde särskilda krav som ställs på dessa plattformarArbete på implementeringen av en adaptiv mellanprogramvara, DyLite,som tillhandahåller självkonfigurerbarhet till småskaliga mikrokontroller,beskrivs och täcks i detalj. DyLite är en delvis implementering av konceptensom utvecklats i DySCAS.Ett annat område som får särskild fokus är formell modellering av QoSoch resurshantering. Idag beskrivs applikationer i dessa områden inte heltformellt, i varje fall inte i den mån att realtidsaspekter täcks in. Att användaformell modellering skulle utöka möjligheterna för verifiering av inte barasystemfunktionalitet, men även resursutnyttjande, tidsaspekter och andraicke-funktionella krav. Denna avhandling innehåller ett förslag på en formalismsom kan användas för dessa syften.Det återstår många utmaningar innan metodik och verktyg som är användbarai en produktionsmiljö kan erbjudas. Många nyckelproblem i områdetbeskrivs, t.ex. versions- och konfigurationshantering, åtkomststyrning ochintegration av olika verktyg, tillsammans med förslag på framtida arbete iövriga områden som täcks av avhandlingen. / DySCAS

Increasing complexity of real-time systems and demands for enabling their configurability and tailorability are strong motivations for applying new software engineering principles such as aspect-oriented and component-based software development. The integration of these two techniques into real-time systems development would enable: (i) efficient system configuration from the components in the component library based on the system requirements, (ii) easy tailoring of components and/or a system for a specific application by changing the behavior (code) of the component by aspect weaving, and (iii) enhanced flexibility of the real-time and embedded software through the notion of system configurability and component tailorability. In this thesis we focus on applying aspect-oriented and component-based software development to real-time system development. We propose a novel concept of aspectual component-based real-time system development (ACCORD). ACCORD introduces the following into real-time system development: (i) a design method that assumes the decomposition of the real-time system into a set of components and a set of aspects, (ii) a real-time component model denoted RTCOM that supports aspect weaving while enforcing information hiding, (iii) a method and a tool for performing worst-case execution time analysis of different configurations of aspects and components, and (iv) a new approach to modelling of real-time policies as aspects. We present a case study of the development of a configurable real-time database system, called COMET, using ACCORD principles. In the COMET example we show that applying ACCORD does have an impact on the real-time system development in providing efficient configuration of the real-time system. Thus, it could be a way for improved reusability and flexibility of real-time software, and modularization of crosscutting concerns. In connection with development of ACCORD, we identify criteria that a design method for component-based real-time systems needs to address. The criteria include a well-defined component model for real-time systems, aspect separation, support for system configuration, and analysis of the composed real-time system. Using the identified set of criteria we provide an evaluation of ACCORD. In comparison with other approaches, ACCORD provides a distinct classification of crosscutting concerns in the real-time domain into different types of aspects, and provides a real-time component model that supports weaving of aspects into the code of a component, as well as a tool for temporal analysis of the weaved system. / <p>Report code: LiU-TEK-LIC-2003:23.</p>

Web-based simulation (WBS) systems offer tradeoffs between user interactivity and hardware requirements striking to seek a balance between the differing concerns. Server-based systems offer little interactivity or concurrent visualization capabilities, while client-based systems have increased hardware requirements asking the user to provide high-end workstations. Concurrent visualization of simulation output proves execution intensive, or unusable in some situations. Creating an execution efficient and user friendly WBS system greatly improves user experience while gaining all of the benefits inherent in a web-based system such as high accessibility and ease of maintenance. In order to provide a usable concurrent visualization WBS this thesis developed the Web-Based Queuing System Simulation System (WebQS3). WebQS3 splits the responsibilities of simulation execution and simulation visualization into a client-server environment; the client is responsible for the visualization display and server is responsible for simulation execution. The system differs from many previous WBS systems in that the client-side application is developed using web-standard technologies such as HTTP, XML, SVG, and ECMAScript instead relying on Java Applets and associated technologies. Using web-standards as the foundation of the client agent opens the visualization and model construction functionality to any user that accesses the application using a web browser while also making the application more scalable in terms of user load. Implementing the client with web-standards also included the development of an asynchronous client-server communication protocol as opposed to traditional synchronous communication protocols used by Java WBS systems. The asynchronous protocol demonstrates similar or better execution performance than similar synchronous communication protocols in most quality characteristics. By creating a WBS system using web-standards implemented in most modern web browsers any user may visit the WebQS3 site and have simulation tools available for use. Providing simulation services on the web makes eases the creation of simulation models my making the tools to readily available while facilitating information sharing and collaboration over the web. The WebQS3 system serves as a model to drive research in WBS systems away from proprietary Java technologies to web standards for front-end visualization technologies. / Master of Science

This dissertation is a multi-disciplinary study, which integrates a software engineering approach with instructional factors in the decision-making, analysis, design and development processes of instructional software. Software engineering models, tools and representations are used in the process of software construction. With reference to the fundamental characteristics of the software product, several disciplines and factors, from both instructional and computing perspectives are considered, and the most appropriate approach/es selected. Software engineering, instructional design and instructional theory are considered as pillars of courseware engineering. The object-oriented design paradigm and a prototyping life-cycle model are found to be most suitable for development of computer-aided instruction. The conceptual study is illustrated by prototype development of a component-based multi-activity practice environment in theoretical Computer Science. It offers perusal or practice, in various instructional modes, according to the user's preferred learning style or need. / Computing / M. Sc. (Information Systems)

El objetivo de la tesis es definir una metodología de desarrollo de aplicaciones de tiempo real basadas en componentes, orientada a aplicaciones cuyos requisitos temporales se especifican utilizando un modelo reactivo de comportamiento temporal. La metodología se construye en base a extensiones que incorporan a las especificaciones, modelos de referencia y procesos estándares propios de la ingeniería de componentes convencionales, esto es, sin requisitos temporales, los datos y los procesos necesarios para la especificación, diseño y análisis de los aspectos relativos al comportamiento temporal. La metodología se sustenta en cuatro contribuciones principales:- Se propone la metodología de modelado modular del comportamiento temporal Mod-MAST, que permite construir el modelo de una aplicación basada en componentes por composición de los modelos de los componentes que la forman. - Se propone la extensión RT-D&C de la especificación Deployment and Configuration of Component-based Distributed Applications de OMG, que permite incluir metadatos relativos a comportamiento temporal en los descriptores de componentes, plataformas de ejecución y aplicaciones. - Se especifica la tecnología de componentes RT-CCM como una extensión de la especificación estándar Lightweight CCM de OMG, que añade los mecanismos necesarios para desarrollar aplicaciones con comportamiento temporal predecible.- Se propone la tecnología de componentes Ada-CCM como implementación concreta de RT-CCM basada en el lenguaje de programación Ada 2005.Todos estos elementos se integran en un proceso completo de diseño de tiempo real de aplicaciones basadas en componentes. / The objective of this work is to define a methodology for the development of real-time component-based applications, focused on applications whose timing requirements are specified according to a reactive model of the timing behaviour. The methodology is built through a set of extensions that incorporate to the standard specifications, reference models and processes typical from the conventional components engineering, i.e. components without timing requirements, the data structures and the processes required for the specification, design and analysis of the aspects related to timing behaviour. The methodology relies on four main contributions:- The Mod-MAST modular modelling methodology, which allows building the real-time model of a component-based application by composing the models of the components that form it.- The RT-D&C extension of the Deployment and Configuration of Component-based Distributed Applications Specification of the OMG, which allows including metadata related to timing behaviour in the descriptors of components, execution platforms and applications.- The RT-CCM components technology, which is an extension of the standard Lightweight CCM Specification of the OMG that incorporates mechanisms to develop applications with predictable timing behaviour.- The Ada-CCM components technology has been developed. It is an implementation of the RT-CCM technology based on the Ada 2005 programming language.All these elements have been integrated in a complete real-time design process for component-based applications.

This dissertation is a multi-disciplinary study, which integrates a software engineering approach with instructional factors in the decision-making, analysis, design and development processes of instructional software. Software engineering models, tools and representations are used in the process of software construction. With reference to the fundamental characteristics of the software product, several disciplines and factors, from both instructional and computing perspectives are considered, and the most appropriate approach/es selected. Software engineering, instructional design and instructional theory are considered as pillars of courseware engineering. The object-oriented design paradigm and a prototyping life-cycle model are found to be most suitable for development of computer-aided instruction. The conceptual study is illustrated by prototype development of a component-based multi-activity practice environment in theoretical Computer Science. It offers perusal or practice, in various instructional modes, according to the user's preferred learning style or need. / Computing / M. Sc. (Information Systems)

The discipline of component-based modeling and simulation offers promising gains including reduction in development cost, time, and system complexity. This paradigm is very profitable as it promotes the use and reuse of modular components and is auspicious for effective development of complex simulations. It however is confronted by a series of research challenges when it comes to actually practice this methodology. One of such important issue is Composability verification. In modeling and simulation (M&amp;S), composability is the capability to select and assemble components in various combinations to satisfy specific user requirements. Therefore to ensure the correctness of a composed model, it is verified with respect to its requirements specifications.There are different approaches and existing component modeling frameworks that support composability however in our observation most of the component modeling frameworks possess none or weak built-in support for the composability verification. One such framework is Base Object Model (BOM) which fundamentally poses a satisfactory potential for effective model composability and reuse. However it falls short of required semantics, necessary modeling characteristics and built-in evaluation techniques, which are essential for modeling complex system behavior and reasoning about the validity of the composability at different levels.In this thesis a comprehensive verification framework is proposed to contend with some important issues in composability verification and a verification process is suggested to verify composability of different kinds of systems models, such as reactive, real-time and probabilistic systems. With an assumption that all these systems are concurrent in nature in which different composed components interact with each other simultaneously, the requirements for the extensive techniques for the structural and behavioral analysis becomes increasingly challenging. The proposed verification framework provides methods, techniques and tool support for verifying composability at its different levels. These levels are defined as foundations of a consistent model composability. Each level is discussed in detail and an approach is presented to verify composability at that level. In particular we focus on theDynamic-Semantic Composability level due to its significance in the overallcomposability correctness and also due to the level of difficulty it poses in theprocess. In order to verify composability at this level we investigate the application ofthree different approaches namely (i) Petri Nets based Algebraic Analysis (ii) ColoredPetri Nets (CPN) based State-space Analysis and (iii) Communicating SequentialProcesses based Model Checking. All the three approaches attack the problem ofverifying dynamic-semantic composability in different ways however they all sharethe same aim i.e., to confirm the correctness of a composed model with respect to itsrequirement specifications. Beside the operative integration of these approaches inour framework, we also contributed in the improvement of each approach foreffective applicability in the composability verification. Such as applying algorithmsfor automating Petri Net algebraic computations, introducing a state-space reductiontechnique in CPN based state-space analysis, and introducing function libraries toperform verification tasks and help the molder with ease of use during thecomposability verification. We also provide detailed examples of using each approachwith different models to explain the verification process and their functionality.Lastly we provide a comparison of these approaches and suggest guidelines forchoosing the right one based on the nature of the model and the availableinformation. With a right choice of an approach and following the guidelines of ourcomponent-based M&amp;S life-cycle a modeler can easily construct and verify BOMbased composed models with respect to its requirement specifications. / <p>Overseas Scholarship for PHD in selected Studies Phase II Batch I</p><p>Higher Education Commision of Pakistan.</p><p>QC 20130224</p>

O planejamento da operação de sistemas hidrotérmicos pode ser classificado como um problema de um sistema acoplado no tempo e no espaço, não linear, não convexo, estocástico e de grande porte. A complexidade do problema justifica a necessidade de utilização de diversas ferramentas computacionais com abordagens variadas. Este trabalho tem como objetivo a realização de estudos relacionados ao planejamento da operação energética de sistemas hidrotérmicos de geração, pela aplicação de componentes de software e de sistemas de inferência fuzzy. Pretende-se apresentar e aplicar um processo de desenvolvimento (UML Components), baseado em componentes de software, para a construção de modelos computacionais de simulação e otimização para servir de apoio ao planejamento da operação energética do sistema hidrotérmico brasileiro. O processo de desenvolvimento UML Components é aplicado de forma a nortear o desenvolvimento do software, para englobar as diferentes atividades realizadas nos fluxos de trabalho, além de incluir os vários artefatos produzidos. Como contribuição adicional, paralelamente ao uso dos componentes de software, este trabalho apresenta uma política de operação energética para reservatórios baseada em sistemas de inferência fuzzy Takagi-Sugeno. A política proposta é baseada na otimização da operação energética das usinas hidrelétricas, empregando o modelo de otimização desenvolvido. Com a operação energética otimizada, obtém-se as relações entre a energia armazenada do sistema e o volume útil operativo de cada usina a reservatório. A partir dessas relações são ajustados os parâmetros do modelo Takagi-Sugeno de ordem um. Ao optar-se por um sistema de inferência fuzzy para determinar a política de operação energética de um conjunto de reservatórios, obtém-se uma estratégia de ação/controle que pode ser monitorada e interpretada, inclusive do ponto de vista lingüístico. Outra vantagem na aplicação de sistemas fuzzy deve-se ao fato dos operadores humanos (especialistas) poderem traduzir, de forma consistente, e em termos de regras lingüísticas, o seu processo de tomada de decisões, fazendo com que a ação do sistema fuzzy seja tão fundamentada e consistente quanto a deles. / The operation planning of hydrothermal power systems can be classified as a nonseparable, nonlinear, nonconvex, stochastic and of large scale optimization problem. The complexity of this problem justifies the need for the use of various computational tools with different approaches. This work aims the accomplishment of studies related to the operation planning of hydrothermal power systems through the implementation of software components and fuzzy inference systems. It is intended to provide and implement a development process (UML Components) based on software components for building computational model of optimization and simulation to support the operation planning of the Brazilian hydrothermal power systems. The UML Components development process is a applied in a way to guide the software development to encompass different activities realized on workflows, as well as to include the various artifacts produced. As additional contribution, in parallel to the use of software components, it is intended to present an operational policy of reservoirs based on Takagi-Sugeno fuzzy inference systems. The proposed policy is based on optimization of hydropower operation, using the optimization model developed. Through the optimized operation, relations between system stored energy and the reservoir volume of each plat are obtained. With these relationships, the parameters of the Takagi-Sugeno model are adjusted. In choosing a fuzzy inference system for determining the operational policy of a set of reservoirs, it is obtained as strategy of action/control that can be monitored and interpreted including linguistic standpoint. Another benefit of the fuzzy system application refers to the fact that human specialists can consistently represent, through linguistic rules, their decision making process, making the fuzzy system action as consistent and sound as theirs.

Automobile système embarqué est une architecture distribuée de l'ordinateur des applications basées sur. La prolifération des systèmes embarqués dans une automobile a apporté de nombreux avantages,tels que le remplacement du système mécanique ancienne avec capteur électronique en réseau et desactionneurs, par exemple, dans des applications telles suspensions adaptatives. Le remplacement des systèmes mécaniques avec ceux électroniques et l'intégration de nouvelles fonctionnalités dans l'électronique soulève une grave préoccupation, c'est de fournir des garanties que ces systèmes embarqués seront en mesure d'effectuer, même dans des environnements difficiles, en particulier dans un système critique pour la sécurité comme un automobile. De plus, ceux-ci l'actualité informatique applications à la demande, imposée par un processus physique.Par exemple, pour éviter un événement catastrophique comme un accident de la demande de freinage doit répondre aux contraintes de minutage. Ce qui implique que la durée de temps entre l'instance de l'application du frein (à la pédale de frein) et l'instance de l'actionnement au niveau des roues d'un véhicule automobile doit être inférieure à la limite. En outre, l'application de freinage est généralement répartie sur le nombre de nœuds, qui sont embarqués communicants les uns avec les autres en utilisant une ressource de communication partagée. Par conséquent, il est important que nous fournissons des garanties que la demande, individuellement et collectivement, est atteinte de ses contrainte temporelle; qui est dans la composition de plusieurs nœuds embarqués. En outre, la prolifération des applications informatiques est également livré avec une hétérogénéité croissante et la complexité de l'architecture intégrée, ce qui conduira à l'augmentation de la complexité de l'analyse pour les systèmes automobiles.Par conséquent, il ya un besoin croissant d'assurer que ces systèmes automobiles embarqués répondre à des contraintes temporelles et de fournir des garanties de sécurité au cours de leur fonctionnement normal ou lors de situations critiques. Cette thèse vise à développer les analyses d'ordonnançabilité pour systèmes automobiles et les réseaux intégrés, avec le but de faciliter,d'une manière rentable et fiable, la conception et l'analyse des systèmes embarqués automobiles. Les analyses sont élaborées et appliquées dans le contexte de l'automobile; de ​​façon à réduire le risque d'échec en raison de délai: les limites du matériel; frais généraux de mise en œuvre, et les interférences dues à la circulation probaliste / Automotive embedded system is a distributed architecture of computer-based applications. The proliferation of embedded systems in an automobile has brought numerous benefits; such as replacement of old mechanical system with networked electronic sensor and actuators, for example, in applications like adaptive suspensions. The replacement of mechanical systems with electronic onesand the integration of new functionality in electronics raises a serious concern; that is to provide guarantees that these embedded systems will be able to perform, even in harsh environments, particularly in a safety-critical system like an automobile.Moreover, these computer-based applications demand timeliness, imposed by a physical process. For example, to avoid a catastrophic event like a crash the braking application has to meet thetiming-constraints. This implies that the time duration between the instance of application of the brake (at brake pedal) and the instance of actuation at the wheels of an automobile should be less than the deadline. Moreover, the braking application is usually spread over number of embedded nodes, which are communicating with each other using a shared communication resource. Therefore, it is important that we provide some guarantees that an application, individually and collectively, is meeting its timing constraint; that is in the composition of multiple embedded nodes. Moreover, theproliferation of computer-based applications also comes with an increasing heterogeneity and complexity of the embedded architecture; which lead to the increase in the complexity of the analysis for the automotive systems Therefore, there is an increasing need to ensure that these automotive embedded systems meet temporal constraints and provide safety guarantees during their normal operation or during critical situations. This thesis aims at developing the schedulability analyses for automotive systems and embedded networks; with the aim to facilitate, in a cost-effective and reliable manner, the design and analysis of automotive embedded systems. The analyses are developed and applied in the automotive context; so as to reduce the risk of deadline failure due to: hardware limitations ; implementation overheads; and nterference due to probabilistic traffic