Search

In this project, a theorical and practical comparison of middleware MQTT is made based on a use of case so as to know and deploy the solution that garantees the fulfillment of a group of requirements that have been inittialy defined offering the best performance based on defined indicators. Firstly, a use of case and the requirements to fulfill are defined. Secondly, the mínimum characteristics that MQTT middlewares have to offer in order to guarantee those requirements are defined. Later, once the MQTT middlewares that do not guarantee one of the requirements have been discarded a performance analysis is performed in order to know who optimizes the performance of some indicators defined in the first instance. Finally, if the optimum solution is known, it is deployed in the defined use of case. Proiektu honetan, erabilera-kasuetan oinarrituta, MQTT-ren teoriko eta praktika konparatiboak konparatu behar dira, hasiera batean definitutako prestazioen serie bat betetzen dela ziurtatzeko irtenbide bat zabaldu eta zabaldu ahal izateko. Lehenik eta behin, erabilera kaskoa eta prestazioak aitortzea definitzen du. Ondoren, MQTT bitarteko erdiek eskaintzen dituzten gutxieneko ezaugarriak definituko dira, horien prestazioak bermatzeko. Posteriormente, los MQTT de los intermediarios descartados que no garanticen alguna de las prestaciones se realiza un análisis de los resultados de los resultantes con el objetivo de conocer qué se optimiza el rendimiento en base a unos indicadores inicialmente definidos. Azkenean, ezagupenaren optimizazioari dagokionean, berau definitutako erabilera desplegatu behar da. En este proyecto, en base a un caso de uso dado se realiza una comparación teórica y práctica de middlewares MQTT para conocer y desplegar la solución que garantice el cumplimiento de una serie de prestaciones inicialmente definidas ofreciendo el mejor rendimiento en base a unos indicadores definidos. Primeramente, se define el caso de uso y las prestaciones a cumplir. A continuación, se definen las características mínimas que han de ofrecer los middlewares MQTT para poder garantizar dichas prestaciones. Posteriormente, descartados los middlewares MQTT que no garanticen alguna de las prestaciones se realiza un análisis del rendimiento de los resultantes con el objetivo de conocer aquel que optimice el rendimiento en base a unos indicadores inicialmente definidos. Finalmente, conocida la solución óptima se procede a desplegar la misma en el caso de uso definido.

Submitted by Ana Rebelo (amsr@isep.ipp.pt) on 2018-11-13T11:26:33Z No. of bitstreams: 1 DM_PedroRibeiro_2017_MEEC.pdf: 18488342 bytes, checksum: e930d52e551c6f10177f5217dd5bb9fe (MD5) Approved for entry into archive by Ana Rebelo (amsr@isep.ipp.pt) on 2018-11-13T11:27:23Z (GMT) No. of bitstreams: 1 DM_PedroRibeiro_2017_MEEC.pdf: 18488342 bytes, checksum: e930d52e551c6f10177f5217dd5bb9fe (MD5) Made available in DSpace on 2018-11-13T11:27:23Z (GMT). No. of bitstreams: 1 DM_PedroRibeiro_2017_MEEC.pdf: 18488342 bytes, checksum: e930d52e551c6f10177f5217dd5bb9fe (MD5) Previous issue date: 2017

My research focuses on distributed programming models, more precisely using ob jects and components. In this area, I provided tools easing the programming of large-scale distributed applications and verifying their correct behaviour. To facilitate the programming of distributed applications, I contributed to the design and the development of languages with a high level of abstraction: active ob jects, algorithmic skeletons, components. To verify correction of the behaviour of an application, I have contributed to the creation of tools for specifying and verifying behavioural distributed applications. My work aims to provide a strong model of programming languages, libraries, and runtime environments provided to the developer, and to guarantee the safe behaviour of distributed applications. During my thesis, I developed the ASP calculus for modelling the behaviour of active ob jects and futures. Since, we created a functional version of this calculus and formalised it in Isabelle/HOL. I also strongly contributed to the definition of a distributed component model - the GCM (Grid Component Model) -, to its formalisation, and to its use for programming adaptive or autonomous components. Finally, I contributed to the specification and behavioural verification of programs based on active ob jects and components, in order to ensure their safe execution. Currently we are working both on a multi-threaded extension of the active ob ject model, better suited for multi-core machine, and on the use of formal methods to design and prove the correction of an algorithm for broadcast on CAN-like peer-to-peer networks (Content Addressable Network). This manuscript provides an overview of all these works.; Mes travaux de recherche portent sur les modèles de programmation distribuée, principalement par objets et composants. Dans ce domaine, j'ai travaillé à fournir des outils facilitant la programmation d'applications distribuées à large échelle et vérifiant la correction de leur comportement. Pour faciliter la programmation d'applications distribuées je me suis intéressé à la mise au point de langages avec un fort niveau d'abstraction: objets actifs, squelettes algorithmiques, composants. Afin de vérifier la correction du comportement d'une application j'ai collaboré à la mise au point d'outils de spécification et de vérification comportementales d'applications distribuées. Mes travaux ont pour but de fournir un modèle formel des langages de programmations, des bibliothèques, et des environnements d'exécution fournies au programmeur afin de garantir un comportement sûr des applications distribuées. Ma thèse m'a permis de mettre au point le calcul ASP modélisant lecomportement des objets actifs et des futurs. Depuis, nous avons créé une version fonctionnelle de ce calcul que nous avons modélisé en Isabelle/HOL. Aussi j'ai fortement contribué à la définition d'un modèle à composants distribués -- le GCM (Grid Component model)--, à sa formalisation et à son utilisation pour programmer des composants adaptables ou autonomes. Enfin, j'ai contribué à la spécification et la vérification comportementale des programmes utilisant des objets actifs et des composants afin de garantir la sûreté de leur exécution. Actuellement, nous travaillons à la fois à une extension multi-threadée du modèle à objets actifs mieux adaptée aux machines multi-coeurs, et à l'utilisation de méthodes formelles pour mettre au point et prouver la correction d'un algorithme de diffusion pour réseau pair-à-pair de type CAN (Content Adressable Network). Ce manuscrit fournit une vue d'ensemble de tous ces travaux.

My research focuses on distributed programming models, more precisely using ob jects and components. In this area, I provided tools easing the programming of large-scale distributed applications and verifying their correct behaviour. To facilitate the programming of distributed applications, I contributed to the design and the development of languages with a high level of abstraction: active ob jects, algorithmic skeletons, components. To verify correction of the behaviour of an application, I have contributed to the creation of tools for specifying and verifying behavioural distributed applications. My work aims to provide a strong model of programming languages, libraries, and runtime environments provided to the developer, and to guarantee the safe behaviour of distributed applications. During my thesis, I developed the ASP calculus for modelling the behaviour of active ob jects and futures. Since, we created a functional version of this calculus and formalised it in Isabelle/HOL. I also strongly contributed to the definition of a distributed component model - the GCM (Grid Component Model) -, to its formalisation, and to its use for programming adaptive or autonomous components. Finally, I contributed to the specification and behavioural verification of programs based on active ob jects and components, in order to ensure their safe execution. Currently we are working both on a multi-threaded extension of the active ob ject model, better suited for multi-core machine, and on the use of formal methods to design and prove the correction of an algorithm for broadcast on CAN-like peer-to-peer networks (Content Addressable Network). This manuscript provides an overview of all these works.; Mes travaux de recherche portent sur les modèles de programmation distribuée, principalement par objets et composants. Dans ce domaine, j'ai travaillé à fournir des outils facilitant la programmation d'applications distribuées à large échelle et vérifiant la correction de leur comportement. Pour faciliter la programmation d'applications distribuées je me suis intéressé à la mise au point de langages avec un fort niveau d'abstraction: objets actifs, squelettes algorithmiques, composants. Afin de vérifier la correction du comportement d'une application j'ai collaboré à la mise au point d'outils de spécification et de vérification comportementales d'applications distribuées. Mes travaux ont pour but de fournir un modèle formel des langages de programmations, des bibliothèques, et des environnements d'exécution fournies au programmeur afin de garantir un comportement sûr des applications distribuées. Ma thèse m'a permis de mettre au point le calcul ASP modélisant lecomportement des objets actifs et des futurs. Depuis, nous avons créé une version fonctionnelle de ce calcul que nous avons modélisé en Isabelle/HOL. Aussi j'ai fortement contribué à la définition d'un modèle à composants distribués -- le GCM (Grid Component model)--, à sa formalisation et à son utilisation pour programmer des composants adaptables ou autonomes. Enfin, j'ai contribué à la spécification et la vérification comportementale des programmes utilisant des objets actifs et des composants afin de garantir la sûreté de leur exécution. Actuellement, nous travaillons à la fois à une extension multi-threadée du modèle à objets actifs mieux adaptée aux machines multi-coeurs, et à l'utilisation de méthodes formelles pour mettre au point et prouver la correction d'un algorithme de diffusion pour réseau pair-à-pair de type CAN (Content Adressable Network). Ce manuscrit fournit une vue d'ensemble de tous ces travaux.

This paper studies the dependability of componentbased applications, especially embedded ones, from the diagnosis point of view. The principle of the diagnosis technique is to implement inter-component tests in order to detect and locate the faulty components without redundancy. The proposed approach for diagnosing faulty components consists of two main aspects. The first one concerns the execution of the inter-component tests which requires integrating test functionality within a component. This is the subject of this paper. The second one is the diagnosis process itself which consists of the analysis of inter-component test results to determine the fault-state of the whole system. Advantage of this diagnosis method when compared to classical redundancy faulttolerant techniques are application autonomy, cost-effectiveness and better usage of system resources. Such advantage is very important for many systems and especially for embedded ones., {"references":["O. Aktouf, M. Wahl and M. Dang, \"Introducing Fault-Diagnosis into\nembedded CORBA-Based Systems\", IEEE International Conference on\nInformation & Communication Technologies, Syria, 2004.","C. Atkinson and H. G. Groß, \"Built-in contract testing in model-driven,\ncomponent-based development\", In ICSR-7 Workshop on Component-\nBased Development Processes, Austin, Texas, 2002.","M. Barborak, M. Makek and A. Dahbura., \"The consensus Problem in\nFault-Tolerant Computing\", ACM Computing Surveys, Vol.25, No.1,\n1993.","N. Belloir, J. M. Bruel and F. Barbier, \"Intégration du test dans les\ncomposants logiciels\", Workshop OCM dans l-ingénierie des SI during\nINFORSID 2002, Nantes, France, 2002.","Cleopatre. Available: http://www.cleopatre-project.org.","A. T. Dahbura, \"An O(n2,5) fault identification algorithm for\ndiagnosticable systems\", IEEE Transactions on Computers, vol. C-33,\nn┬░6, p. 486-492, June 1984.","F. Favarim, J. Fraga and F. Siqueira, \"Fault-tolerant CORBA\nComponents\" In 2nd Workshop on Reflective and Adaptive Middleware,\np. 144-148, Rio de Janeiro, Brazil, 2003.","J. Fraga, F. Siqueira and F. Favarim, \"An Adaptive Fault-Tolerant\nComponent Model\", 9th IEEE International Workshop on Object-\nOriented Real-Time Dependable Systems, Capri Island, Italy, 2003.","R. Bianchini, R. W. Buskens, \"An adaptative distributed system level\ndiagnosis algorithm and its implementation\", Proceedings of the 21st\ninternational IEEE Symposium on Fault-Tolerant Computing, p. 616-\n626, 1991.\n[10] H. G. Groß, \"Built-in Contrat Testing in Component-based Application\nEngineering\", CologNet Joint Workshop on Component-based Software\nDevelopment and Implementation Technology for Computational Logic,\nAffiliated with LOPSTR, Madrid, Spain, 19-20 September 2002.\n[11] ICM. Available: http://www.icmgworld.com.\n[12] H. Kopetz, and T. Wien, \"DECOS - European Integrated Project\nProposal\". Available: https://www.decos.at/download/021003-\nDECOS.Grenoble-US.pdf/, October 2002.\n[13] K. S. Lee and G. Shin, \"Probabilistic Diagnosis of Multiprocessor\nSystems\", ACM Computing Surveys, Vol.26, No.1, 1994.\n[14] E. Martins, C. M. Toyota and R. L. Yanagawa, \"Constructing Self-\nTestable Software Components\", Proceedings of the 2001 International\nConference on Dependable Systems and Networks, p. 151-160,\nGöteborg, Sweden, July 2001.\n[15] V. Marangozova and D. Hagimont, \"An Infrastructure for CORBA\nComponent Replication\", 1st IFIP/ACM Working Conference on\nComponent Deployment, Berlin, Germany, June 2002.\n[16] Microsoft, \"Overview of the .NET Framework\", MSDN Library White\nPaper, 2001. Available: http://msdn.microsoft.com.\n[17] CORBA Components, OMG Document formal/02-06-65, 2002.\nAvailable: http://www.omg.org.\n[18] OpenCCM. Available: http://www.objectweb.org.\n[19] Prerapata, Metz, Chien., \"On the connection assignment problem of\ndiagnosticable systems\", IEEE Transactions on Electronic Computers,\nvol. EC-16, n┬░6, p. 848-854, December 1967.\n[20] Sun Microsystems, \"Enterprise JavaBeans Specification\", v2.0. 2001.\nAvailable: http://java.sun.com/ejb/.\n[21] Y. Wang, \"On Built-In Test Reuse in Object-Oriented Framework\nDesign\", ACM Computing Surveys, 32(1), March, 2002."]}

This paper describes a new software/hardware architecture for processing wide area airborne camera images in real time. The images under consideration are acquired from the 3K-camera system developed at DLR (German Aerospace Center). It consists of three off-the-shelf cameras, each of it delivers 16 Mpixel three times a second. One camera is installed in nadir, whereas the other two cameras are looking in side direction. Main applications of our system are supposed to be automotive traffic monitoring, determining the workload of public road networks during mass events, or obtaining a survey of damages in disaster areas in real time. Altogether, this demands a fast image processing system on the aircraft, because the amount of original high resolution images can not be sent to ground by up-to-date transfer mode systems. The on-board image processing system is distributed over a local network. On each PC several modules are running concurrently. In order to synchronize several processes and to assure access to commonly used data, a new distributed middleware for real time image processing is introduced. Two sophisticated modules one for orthorectification of images and one for traffic monitoring are explained in more detail. The orthorectification and mosaicking is executed on the fast graphics processing unit on one PC, whereas the traffic monitoring module runs on another PC in the on-board network. The resulting image data and evaluated traffic parameters are sent to a ground station in near real time and are distributed to the involved users. Thus, with the here suggested software/hardware system it becomes possible to support rescue forces and security forces in disaster areas or during mass events in near real time.

Peer-to-peer applications enable a group of users to create a communications framework from scratch without the need of a central service provider. This is achievable via the aggregation of resources each one of them provide, creating a completely distributed collaborative environment based in a flat hierarchy of users, without the need for centralization. Usually, peer-to-peer applications are conceptualized as a global network, without any kind of logical segmentation or segregation as far as resource availability is concerned. At every model, any peer may access any resource available within the network just by being able to reach the peer that provides such resource. Although having a unique huge open network may be desirable for some applications, there are cases in which it might be interesting to create different, but not necessarily disjoint, groups of peers operating under the same global peer-topeer network. In order for peer groups to be able to operate effectively in a global peer-to-peer network, additional security services must be provided. These mechanisms should allow peers to be able to prove group membership to other members of the group, so they can be granted access to group resources, as well as ensuring that resource discovery and message exchange between peer group members remain secure. A group may need to limit membership for various reasons, such as ensuring privacy, anonymity or enforcing that peer group members are up to some specific parameter (data shared, performance, computing power, etc.) The goals of this PhD. thesis are twofold, the reason being the fact that securing a peer group can be divided at two distinct, but interrelated, layers: • Enabling effective group membership, starting from the process by which any peer becomes part of a peer group and then, following, the mechanisms by which such peer may prove its membership to other group members for the rest of the membership's lifecycle (peer group access control). • Providing a secure environment for standard operations within a peer group, which functions once any peer's membership to the group has already been established. Typical operations at this layer are those of resource location and retrieval, or messaging. In order to achieve the former goal, basic group membership and access control scenarios are categorized and formalized as part of the research work in order to assess which are the current challenges. From this study, we present a generic model proposal that fulfils the objectives of autonomy, keeps a pure peer-to-peer model and the possibility to be used in different peer-to-peer frameworks. The later goal focuses in secure mechanisms in order to provide basic security services to both resource discovery and message exchange. However, in contrast with group membership models, where a generic approach is feasible, peer group operation security is intimately tied to each specific peer-to-peer framework, since each one specifies resource location and messaging primitives in a different manner. For that reason, a specific one has been chosen for the research work: JXTA. Such election is due to the fact that JXTA's architecture is entirely based on the concept of peer groups, since it was the one to first define the concept of peer group, providing an excellent testbed for peer group research

The use of networks for communications between the electronic control units (ECU) of a vehicle in production cars dates from the beginning of the 1990s. The specific requirements of the different car domains have led to the development of a large number of automotive networks such as Local Interconnect Network, J1850, CAN, TTP/C, FlexRay, media-oriented system transport, IDB1394, etc. This paper first introduces the context of in-vehicle embedded systems and, in particular, the requirements imposed on the communication systems. Then, a comprehensive review of the most widely used automotive networks, as well as the emerging ones, is given. Next, the current efforts of the automotive industry on middleware technologies, which may be of great help in mastering the heterogeneity, are reviewed. Finally, we highlight future trends in the development of automotive communication systems.

http://www.taylorandfrancis.com/; X-by-Wire is a generic term referring to the replacement of mechanical or hydraulic systems, such as braking or steering, by electronic ones. In this chapter, we analyze the real-time and dependability constraints of X-by-Wire systems, review the fault-tolerant services that are needed and the communication protocols (TTP/C, FlexRay and TTCAN) considered for use in such systems. Using a Steer-by-Wire case-study, we detail the design principles and verification methods that can be used to ensure the stringent constraints of X-by-Wire systems.

http://www.taylorandfrancis.com/; Due to the increasing criticality of the functions in terms of safety, embedded automotive systems must now respect stringent dependability constraints despite the faults that may occur in a very harsh environment. In a context where critical functions are distributed over the network, the communication system plays a major role. First, we discuss the main services and functionalities that a communication system should offer for easying the design of fault-tolerant applications in the automotive context. Then, we review the features of the protocols that are currently considered for being used and, finally, we highlight areas where developments are still needed.

This report summarises the presentations, discussions, and main results of the ECOOP'01 Workshop on Object-Oriented Business Solutions (WOOBS). It was not a pure scientific meeting, but a mixed gathering where people from the industry and the academia met to exchange ideas, experiences and build a network of relationships with others committed to the emergence of object-oriented business solutions. WOOBS had an invited talk on quality of service, twelve presentations and lively discussions during and after them. The main conclusions were on the importance of Multi-Organisational Web-Based Systems in today's e-commerce world, which justifies the study of a new multidisciplinary paradigm called Web-Oriented Programming.