1,721,221 research outputs found
Dynamic Data Adaptation for the Synthesis and Deployment of Protocol Mediators
No full textDans la plupart des systèmes disponibles aujourd'hui l'interopérabilité est fournie comme une capacité statique qui est le résultat d'une intégration conçue manuellement. En conséquence, un nombre important de systèmes fonctionnellement compatibles ne sont pas conçues pour être interopérables. L'objectif de cette thèse est de permettre l'interopérabilité automatisée des protocoles pour les systèmes, services et applications à travers des médiateurs de protocoles synthétisés dynamiquement. Les médiateurs représentent des composants logiciels qui peuvent coordonner les interactions entre deux ou plusieurs systèmes fonctionnellement compatibles, en utilisant les différents moyens de communication (réseaux IP, IPC, la mémoire partagée, etc.). Les médiateurs synthétisés dynamiquement devraient permettre aux applications de s'adapter sans difficulté aux protocoles a priori inconnus, soutiennent l'évolution de ces protocoles tout en contournant les contraintes des systèmes du monde réel, comme celles introduites par la mobilité de l'appareil et des systèmes d'exploitation. Dans cette thèse, nous nous concentrons sur les problèmes de recherche liés à l'automatisation du processus d'adaptation de données dans le cadre de la médiation de protocoles. L'adaptation des données est une étape clé dans la médiation de protocoles qui ne peut pas être résolu indépendamment. Cette dépendance devient visible lorsque les systèmes reposant sur des piles de protocoles complexes doivent être rendus interopérables, malgré les dépendances inter-couche à l'intérieur des données échangées. Il y a la nécessité d'un cadre qui synthétise les médiateurs, tout en tenant compte de l’adaptation de données.In most systems available today interoperability is provided as a static capability that is the result of manually designed and hand coded integration. In consequence, a substantial number of functionally-compatible systems are not conceived to be interoperable. The focus of this thesis is to enable automated protocol interoperability for systems, services and applications through the means of dynamically synthesized protocol mediators. Protocol mediators represent concrete software components which can coordinate interactions between two or more functionally-compatible systems, relying on various means of communication (IP networks, personal area networks, inter-process communication, shared memory, etc.). Dynamically synthesised mediators should allow applications to seamlessly adapt to a priori unknown protocols, support the evolution of such protocols while circumventing real-world system constraints, such as those introduced by device mobility and operating system differences. In this thesis we focus on the research problems related to automating the process of data adaptation in the context of protocol mediation. Data adaptation is a key phase in protocol mediation that cannot be solved independently. This strong dependence becomes visible when systems relying on multilayer protocol stacks have to be made interoperable, despite cross-layer dependencies inside the exchanged data. There is the need of a frame- work that synthesises mediators while taking into account cross-layer data adaptation
Query by combination in the internet of things
Get PDFIn the Internet of Things, physical objects, or Things, are integrated into a virtual world that harbors capabilities to augment the physical appearance of those Things with additional information. In this paper, we present a software solution that enables users to deduce additional information from Things by querying the relations between them. These relations are represented by a joint knowledge base that is constructed on the fly from ontologies that are associated with the Things. Based on the information found in the acquired knowledge, suitable applications are instantiated to process and represent the knowledge about the Things to the user. The practical use of the presented solution is illustrated by a concrete scenario.status: Publishe
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Enabling emergent mobile systems in the IoT : from middleware-layer communication interoperability to associated QoS analysis
No full textLes applications de l'Internet des objets (IdO/IoT) se composent de divers objets en grande partie mobiles et avec des ressources limitées ou riches. Des tels dispositifs exigent des interactions légères et faiblement couplées en termes de temps, d'espace et de synchronisation. Les protocoles au niveau middleware de l'IoT prennent en charge un ou plusieurs types d'interaction assurant la communication entre objets. De plus, ils supportent différents niveaux de Qualité de service (QDS) pour cette communication par rapport aux ressources disponibles sur les dispositifs et les réseaux. Les dispositifs utilisant le même protocole middleware interagissent de manière homogène, car ils exploitent les mêmes caractéristiques fonctionnelles et de QDS. Cependant, la profusion de protocoles middleware pour l'IoT se traduit par des objets très hétérogènes. Cela nécessite des solutions d'interopérabilité avancées intégrées à des techniques de modélisation et d'évaluation de la QDS. La principale contribution de cette thèse est d'introduire une approche et de fournir une plate-forme pour la synthèse automatique des artefacts logiciels permettant l'interopérabilité. De tels artefacts permettent l'interconnexion entre des objets mobiles qui utilisent des protocoles hétérogènes au niveau middleware. Notre plate-forme prend en charge l'évaluation de l'effectivité de l'interconnexion en termes de la QDS de bout en bout. Plus précisément, nous dérivons des conditions formelles pour des interactions réussies, et nous permettons la modélisation et l'analyse des performances ainsi que le réglage du système de bout en bout, tout en considérant plusieurs paramètres système pour l'IoT mobile.Internet of Things (IoT) applications consist of diverse Things including both resource-constrained/rich devices with a considerable portion being mobile. Such devices demand lightweight, loosely coupled interactions in terms of time, space, and synchronization. IoT middleware protocols support one or more interaction types (e.g., asynchronous messaging, streaming) ensuring Thing communication. Additionally, they introduce different Quality of Service (QoS) features for this communication with respect to available device and network resources. Things employing the same middleware protocol interact homogeneously, since they exploit the same functional and QoS features. However, the profusion of developed IoT middleware protocols introduces technology diversity which results in highly heterogeneous Things. Interconnecting heterogeneous Things requires mapping both their functional and QoS features. This calls for advanced interoperability solutions integrated with QoS modeling and evaluation techniques. The main contribution of this thesis is to introduce an approach and provide a supporting platform for the automated synthesis of interoperability software artifacts. Such artifacts enable the interconnection between mobile Things that employ heterogeneous middleware protocols. Our platform further supports evaluating the effectiveness of the interconnection in terms of end-to-end QoS. More specifically, we derive formal conditions for successful interactions, and we enable performance modeling and analysis as well as end-to-end system tuning, while considering several system parameters related to the mobile IoT
Generating Connectors for Homogenous and Heterogenous Deployment
Get PDFSoftware connectors are typically used in component-based engineering to model and realize component interconnections. Connectors play an important role both at design time, when they allow for specifying the way components interact, and at runtime, when they actually implement the specified interactions in particular target environments. Connectors also help with deployment (both homogeneous and heterogeneous) by allowing for seamless distribution and overcoming incompatibilities between components and component systems by utilizing adaptors. An important aspect of employing connectors is the amount of work connected with their use. In this context, to make connectors truly an asset, it is necessary to allow for generating their runtime implementations based on design-time specification. This is however a problem (mainly because of the semantic gap between the connector specification and its implementation), which has not been sufficiently addressed so far, especially when trying to use connectors in the context of heterogeneous deployment. In this thesis, we propose a technique of automatic generation of a connector implementation based on a high-level connector specification. The thesis focuses on building connectors in the scope of homogeneous and heterogeneous deployment, which means that the generated..
Data stream management system for the future internet of things
No full textL'Internet des objets (ou IdO) se traduit à l'heure actuelle par l'accroissement du nombre d'objets connectés, c'est-à-dire d'appareils possédant une identité propre et des capacités de calcul et de communication de plus en plus sophistiquées : téléphones, montres, appareils ménagers, etc. Ces objets embarquent un nombre grandissant de capteurs et d'actionneurs leur permettant de mesurer l'environnement et d'agir sur celui-ci, faisant ainsi le lien entre le monde physique et le monde virtuel. Spécifiquement, l'Internet des objets pose plusieurs problèmes, notamment du fait de sa très grande échelle, de sa nature dynamique et de l'hétérogénéité des données et des systèmes qui le composent (appareils puissants/peu puissants, fixes/mobiles, batteries/alimentations continues, etc.). Ces caractéristiques nécessitent des outils et des méthodes idoines pour la réalisation d'applications capables (i) d'extraire des informations utiles depuis les nombreuses sources de données disponibles et (ii) d'interagir aussi bien avec l'environnement, au moyen des actionneurs, qu'avec les utilisateurs, au moyen d'interfaces dédiées. Dans cette optique, nous défendons la thèse suivante : en raison de la nature continue des données (mesures physiques, évènements, etc.) et leur volume, il est important de considérer (i) les flux comme modèle de données de référence de l'Internet des objets et (ii) le traitement continu comme modèle de calcul privilégié pour transformer ces flux. En outre, étant donné les préoccupations croissantes relatives à la consommation énergétique et au respect de la vie privée, il est préférable de laisser les objets agir au plus près des utilisateurs, si possible de manière autonome, au lieu de déléguer systématiquement l'ensemble des tâches à de grandes entités extérieures telles que le cloud. À cette fin, notre principale contribution porte sur la réalisation d'un système distribué de gestion de flux de données pour l'Internet des objets. Nous réexaminons notamment deux aspects clés du génie logiciel et des systèmes distribués : les architectures de services et le déploiement. Ainsi, nous apportons des solutions (i) pour l'accès aux flux de données sous la forme de services et (ii) pour le déploiement automatique des traitements continus en fonction des caractéristiques des appareils. Ces travaux sont concrétisés sous la forme d'un intergiciel, Dioptase, spécifiquement conçu pour être exécuté directement sur les objets et les transformer en fournisseurs génériques de services de calcul et de stockage.Pour valider nos travaux et montrer la faisabilité de notre approche, nous introduisons un prototype de Dioptase dont nous évaluons les performances en pratique. De plus, nous montrons que Dioptase est une solution viable, capable de s'interfacer avec les systèmes antérieurs de capteurs et d'actionneurs déjà déployés dans l'environnement.The Internet of Things (IoT) is currently characterized by an ever-growing number of networked Things, i.e., devices which have their own identity together with advanced computation and networking capabilities: smartphones, smart watches, smart home appliances, etc. In addition, these Things are being equipped with more and more sensors and actuators that enable them to sense and act on their environment, enabling the physical world to be linked with the virtual world. Specifically, the IoT raises many challenges related to its very large scale and high dynamicity, as well as the great heterogeneity of the data and systems involved (e.g., powerful versus resource-constrained devices, mobile versus fixed devices, continuously-powered versus battery-powered devices, etc.). These challenges require new systems and techniques for developing applications that are able to (i) collect data from the numerous data sources of the IoT and (ii) interact both with the environment using the actuators, and with the users using dedicated GUIs. To this end, we defend the following thesis: given the huge volume of data continuously being produced by sensors (measurements and events), we must consider (i) data streams as the reference data model for the IoT and (ii) continuous processing as the reference computation model for processing these data streams. Moreover, knowing that privacy preservation and energy consumption are increasingly critical concerns, we claim that all the Things should be autonomous and work together in restricted areas as close as possible to the users rather than systematically shifting the computation logic into powerful servers or into the cloud. For this purpose, our main contribution can be summarized as designing and developing a distributed data stream management system for the IoT. In this context, we revisit two fundamental aspects of software engineering and distributed systems: service-oriented architecture and task deployment. We address the problems of (i) accessing data streams through services and (ii) deploying continuous processing tasks automatically, according to the characteristics of both tasks and devices. This research work lead to the development of a middleware layer called Dioptase, designed to run on the Things and abstract them as generic devices that can be dynamically assigned communication, storage and computation tasks according to their available resources. In order to validate the feasability and the relevance of our work, we implemented a prototype of Dioptase and evaluated its performance. In addition, we show that Dioptase is a realistic solution which can work in cooperation with legacy sensor and actuator networks currently deployed in the environment
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