Data Driven Adaptation of Heterogeneous Service-Oriented Processes

Η με βάση τα δεδομένα προσαρμογή διαδικασιών αποτελεί μια επέκταση της έννοιας των Δυναμικών και με βάση τα Δεδομένα Καθοδηγουμενων Συστήματων (DDDAS) όπως αυτά έχουν καθοριστεί από την Δαρεμά. Συγεκριμένα όπως και στα DDDAS συστήματα η προσέγγιση μας επιτρέπει την προσφορά προσαρμοζόμενων διαδικασιών χρησιμοποιώντας διαθέσιμες πληροφορίες και υπηρεσίες. H προσφορά προσαρμοζόμενων διαδικασιών περιλαμβάνει την αναγνώριση και χρήση πιθανών εναλλακτικών μονοπατιών εκτέλεσης (ή διαδρομών) για την επίτευξη των στόχων και υπό-στόχων της κάθε διαδικασίας. Τα εναλλακτικά μονοπάτια λαμβάνουν υπόψη και χρησιμοποιούν σχετικές πληροφορίες ή/και υπηρεσίες (ή συνθέσεις υπηρεσιών). Για την αναζήτηση των πιθανών εναλλακτικών χρησιμοποιούνται τεχνικές από το χώρο της Τεχνητής Νοημοσύνης Σχεδιασμού (AI Planning) και της υπολογιστικής Πλαισίου (Context-Aware computing) κατά τον χρόνο διάθεσης της διαδικασίας. Κατά τον υπολογισμό των πιθανών εναλλακτικών, στόχος της προσέγγισης μας είναι η μείωση των βημάτων εκτέλεσης, δλδ του πλήθους των εργασιών της διαδικασίας που έχουν οριστείIn principle the Data-Driven Process Adaptation (DDPA) approach is based on the concept of Dynamic Data Driven Application Systems (DDDAS) as this is stated by Darema in [8]. In accordance to the DDDAS notion such systems support the utilization of appropriate information at specific decision points so as to make real systems more efficient. In this regard, DDPA accommodates the provision of adaptable service processes by exploiting the use of information available to the process environment in addition to existing services. Adaptation in the context of our approach includes the identification and use of possible alternatives for the achievement of the goals and sub-goals defined in a process; alternatives include the utilization of available related information and/or services (or service chains). Data-Driven adaptation incorporates AI planning and Context-Aware Computing techniques to support the identification of possible alternatives at deployment time. When calculating the possible alternatives the goal of our approach is to reduce the number of steps, i.e. number of process tasks, defined in the original process

Semantic coordination through programmable Tuple spaces

Two of the main features of today complex software systems like pervasive computing systems and Internet-based applications are distribution and openness. Distribution revolves around three orthogonal dimensions: (i) distribution of control|systems are characterised by several independent computational entities and devices, each representing an autonomous and proactive locus of control; (ii) spatial distribution|entities and devices are physically distributed and connected in a global (such as the Internet) or local network; and (iii) temporal distribution|interacting system components come and go over time, and are not required to be available for interaction at the same time. Openness deals with the heterogeneity and dynamism of system components: complex computational systems are open to the integration of diverse components, heterogeneous in terms of architecture and technology, and are dynamic since they allow components to be updated, added, or removed while the system is running. The engineering of open and distributed computational systems mandates for the adoption of a software infrastructure whose underlying model and technology could provide the required level of uncoupling among system components. This is the main motivation behind current research trends in the area of coordination middleware to exploit tuple-based coordination models in the engineering of complex software systems, since they intrinsically provide coordinated components with communication uncoupling and further details in the references therein. An additional daunting challenge for tuple-based models comes from knowledge-intensive application scenarios, namely, scenarios where most of the activities are based on knowledge in some form|and where knowledge becomes the prominent means by which systems get coordinated. Handling knowledge in tuple-based systems induces problems in terms of syntax - e.g., two tuples containing the same data may not match due to differences in the tuple structure - and (mostly) of semantics|e.g., two tuples representing the same information may not match based on a dierent syntax adopted. Till now, the problem has been faced by exploiting tuple-based coordination within a middleware for knowledge intensive environments: e.g., experiments with tuple-based coordination within a Semantic Web middleware (surveys analogous approaches). However, they appear to be designed to tackle the design of coordination for specic application contexts like Semantic Web and Semantic Web Services, and they result in a rather involved extension of the tuple space model. The main goal of this thesis was to conceive a more general approach to semantic coordination. In particular, it was developed the model and technology of semantic tuple centres. It is adopted the tuple centre model as main coordination abstraction to manage system interactions. A tuple centre can be seen as a programmable tuple space, i.e. an extension of a Linda tuple space, where the behaviour of the tuple space can be programmed so as to react to interaction events. By encapsulating coordination laws within coordination media, tuple centres promote coordination uncoupling among coordinated components. Then, the tuple centre model was semantically enriched: a main design choice in this work was to try not to completely redesign the existing syntactic tuple space model, but rather provide a smooth extension that { although supporting semantic reasoning { keep the simplicity of tuple and tuple matching as easier as possible. By encapsulating the semantic representation of the domain of discourse within coordination media, semantic tuple centres promote semantic uncoupling among coordinated components. The main contributions of the thesis are: (i) the design of the semantic tuple centre model; (ii) the implementation and evaluation of the model based on an existent coordination infrastructure; (iii) a view of the application scenarios in which semantic tuple centres seem to be suitable as coordination media

Locations of Practice: The Social Production of Locative Media

Locative media is a descriptive term that designates the artistic deployment of an assemblage of mobile and location aware technologies in the production of site-specific experiences or installations for public spaces. It has been described as a ‘test-category’ or ‘mobile media movement’ through which a wide gamut of individuals and collectives explore the possibilities of emerging mobile and location-based technologies. Underlying theoretical concerns have focused, for instance, on: reconfigurations of understandings and experiences of space; associations with psychogeography; potential for grass roots activist applications; and, the dependency on technological infrastructures associated with power and control. A fundamental tension exists between the tools employed in production, those being commercial technologies, and the rhetoric of locative media practice, which posits these technologies as deployable beyond command and control infrastructures. Concealed within this tension is the manner in which locative media production abuts the commercial uptake of mobile and location-based technologies, and the specific practices that support the appropriation of commercial channels for non-commercial means. This thesis engages with circumstances that enable (or not) locative media production. Locative media is framed as a consequence of social relations, and, as a field of cultural production set within contextual and contingent conditions that circumscribe practice. In focusing on the conditions of production, that is, the processes through which locative media experiences are constructed, I provide site-specific interpretations through two case studies. The analysis elucidates what is not readily apparent in a final aesthetic experience and reveals the conditions and constraints of production, including the manner in which certain practices are legitimized, disavowed and contradicted. The practices to ensue from these particular sites of production are not representative of the entire field of locative media. These engagements articulate specific locations of practice; the physical and symbolic spaces that support the production of locative media, and it is within these spaces of production that practices emerge

Digital material: tracing new media in everyday life and technology

Three decades of societal and cultural alignment of new media have yielded a host of innovations, trials, and problems, accompanied by versatile popular and academic discourse. New Media Studies crystallized internationally into an established academic discipline, and this begs the question: where do we stand now? Which new questions are emerging now that new media are being taken for granted, and which riddles are still unsolved? Is contemporary digital culture indeed all about 'you', the participating user, or do we still not really understand the digital machinery and how this constitutes us as 'you'? The contributors to the present book, all employed in teaching and researching new media and digital culture, assembled their 'digital material' into an anthology, covering issues ranging from desktop metaphors to Web 2.0 ecosystems, from touch screens to blogging and e-learning, from role-playing games and cybergothic music to wireless dreams. Together the contributions provide a showcase of current research in the field, from what may be called a 'digital-materialist' perspective.Nieuwe media zijn vanaf hun opkomst begeleid door revolutionaire beloften en bedreigingen: hypertekst zou lezers veranderen in auteurs, digitale beelden zouden de waarheid en werkelijkheid ondermijnen, en online communicatie zou alle afstanden overbruggen. 'Cyberspace' werd gevierd dan wel gevreesd als immaterieel en autonoom, losgezongen van onze dagelijkse leefwereld. Na twee decennia 'cyberrevolutie' zijn nieuwe media vanzelfsprekend geworden en blijken zij allesbehalve immaterieel. Vanuit dat perspectief belicht de bundel Digital Material digitale culturen. De bijdragen onderzoeken onder meer computer games, mobiele communicatie, interfacemetaforen, weblogculturen, software ontwikkeling en digitale beeldproductie. Bij elkaar vormen zij een inspirerend theoretisch kader om de hedendaagse betekenis van nieuwe media te doorgronden

ADAPTIVE PROBABILISTIC ROADMAP CONSTRUCTION WITH MULTI-HEURISTIC LOCAL PLANNING

The motion planning problem means the computation of a collision-free motion for a movable object among obstacles from the given initial placement to the given end placement. Efficient motion planning methods have many applications in many fields, such as robotics, computer aided design, and pharmacology. The problem is known to be PSPACE-hard. Because of the computational complexity, practical applications often use heuristic or incomplete algorithms. Probabilistic roadmap is a probabilistically complete motion planning method that has been an object of intensive study over the past years. The method is known to be susceptible to the problem of “narrow passages”: Finding a motion that passes a narrow, winding tunnel can be very expensive. This thesis presents a probabilistic roadmap method that addresses the narrow passage problem with a local planner based on heuristic search. The algorithm is suitable for planning motions for rigid bodies and articulated robots including multirobot systems with many degrees-of-freedom. Variants of the algorithm are describe

Digital Material

Three decades of societal and cultural alignment of new media have yielded a host of innovations, trials, and problems, accompanied by versatile popular and academic discourse. New Media Studies crystallized internationally into an established academic discipline, and this begs the question: where do we stand now? Which new questions are emerging now that new media are being taken for granted, and which riddles are still unsolved? Is contemporary digital culture indeed all about 'you', the participating user, or do we still not really understand the digital machinery and how this constitutes us as 'you'? The contributors to the present book, all employed in teaching and researching new media and digital culture, assembled their 'digital material' into an anthology, covering issues ranging from desktop metaphors to Web 2.0 ecosystems, from touch screens to blogging and e-learning, from role-playing games and cybergothic music to wireless dreams. Together the contributions provide a showcase of current research in the field, from what may be called a 'digital-materialist' perspective

DIFFRACTING REPRESENTATION: TOWARDS A SITUATED AESTHETICS OF TECHNOSPACES

Thesis embargoed until 01-09-2017. Embargo set on 04/08/2015 by CLC, Graduate School.My research for this thesis focusses on the concepts of representation and space in order to demonstrate their theoretical and practical co-implications. Discussing various theorists of space in the first part and analyzing a number of artists and artworks as case studies in the second part, I elaborate a critique of the representational imaginary in order to articulate an alternative notion of representation by means of which a relational, qualitative and performative spatiality can emerge. I specifically focus on technospaces, which I consider a privileged field for observing the intersections of representation and spatiality; it is a field in which the use of spatial metaphors abounds, very often relying on a series of dichotomies (such as location and mobility, the real and the virtual) that have employed and, in most cases, reinforced the traditional idiom of representational. Drawing on the lessons of feminist theory, particularly on approaches to the politics of location, from Adrienne Rich‘s initial formulation to the situated knowledge theorized by Donna Haraway, I elaborate a situated aesthetics of technospaces in which the observer‘s engagement with representational practices replaces the view from a distance of traditional representation, so that her/his position is accounted for together with the history of the production of space and its multiple representations. For this reason, I also formulate an articulatory turn in representation based on Haraway‘s semiotics in order to propose a non-reflexive notion of representation in which invention and factuality eventually meet

Reconversion des héritages olympiques et rénovation de l'espace urbain : le stade olympique comme vecteur de développement

Les Jeux Olympiques d'été (J.O.) sont devenus depuis leur professionnalisation (années 70) le second événement sportif le plus médiatisé après la Coupe du Monde de soccer et le plus coûteux au monde conduisant ainsi une augmentation considérable de ses impacts sur les milieux urbains les accueillant. Ces répercussions urbaines se traduisent notamment par la nécessité de planifier la gestion des équipements olympiques nécessaires pour l'organisation de cette manifestation. En effet, cet événement sportif majeur est désormais un projet urbain extrêmement complexe et dispendieux pour les villes hôtes, utilisé entre autres à des fins de réaménagement, de régénération voire de repositionnement urbains, où les acteurs présents, qu'ils soient publics ou privés, se doivent de répondre aux attentes organisationnelles des Jeux tout en envisageant la reconversion de ces équipements. La gestion des héritages olympiques devient donc un domaine de planification primordial pour ces métropoles olympiques et ce dès la mise en candidature de ces projets. De ces logiques structurelles, on observe que la problématique de reconversion du Stade olympique est récurrente puisque cette infrastructure, la plus importante du Parc Olympique, nécessite non seulement des financements colossaux pour sa construction, mais également des investissements majeurs pour sa gestion. Malgré certaines mesures de planification stratégique, mises en place et justifiées par les responsables de ces projets pour encadrer et légitimer ces mégaprojets, il est intéressant de remarquer qu'un très faible pourcentage de ces stades sont véritablement utilisés après les J.O. et ne deviennent pas des « éléphants blancs » pour ces villes hôtes. Cette réflexion doctorale, appuyée par des cas olympiques d'étude précis (Montréal 1976, Barcelone 1992 et Sydney 2000), nous permet de poser l'hypothèse que l'élaboration dans la phase pré-olympique, pour la planification de l'aménagement du Stade olympique, de stratégies urbanistiques, financières et gestionnaires flexibles, adaptées à la trame urbaine métropolitaine et renouvelées dans le contexte post-olympique facilite la reconversion de cet équipement. Ce travail d'analyse a été conçu d'un point de vue théorique sous l'angle des concepts de projet urbain, de grand projet urbain et de régénération urbaine et a été mené au niveau méthodologique via une démarche qualitative en vertu d'un design de recherche flexible et d'une approche inductive et interprétative pour laquelle les techniques de collecte de données de l'analyse de contenu, de l'analyse de données secondaires, d'entrevues semi-dirigées et l'observation non-participante ont été utilisées. Ces stratégies conceptuelles et méthodologiques nous ont permis de présenter, au terme de ce travail doctoral, un modèle analytique global recensant les stratégies urbanistiques, récréotouristiques, financières et gestionnaires pré et post olympiques, et ce dans le but de mieux comprendre pourquoi et comment certains Stades olympiques réussissent mieux leurs reconversions que d'autres. À la lumière des analyses effectuées, nous concluons que le processus de planification et d'aménagement du Stade olympique doit être intégré dans le plan d'urbanisme maître de la ville hôte et du territoire d'insertion. Parallèlement, nous estimons que sa structure architecturale et sa capacité d'accueil sont tenues d'être aménagées en fonction des stades déjà existants au niveau métropolitain. Enfin, les nouveaux principes de gouvernance d'un équipement sportif majeur sont susceptibles d'être appliqués de manière à faciliter la reconversion de cet édifice. \ud ______________________________________________________________________________ \ud MOTS-CLÉS DE L’AUTEUR : Jeux Olympiques d'été, Stade olympique, reconversion des héritages olympiques, Montréal, Barcelone, Sydney