Made available in DSpace on 2015-03-05T14:01:20Z (GMT). No. of bitstreams: 0 Previous issue date: 30 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Ao longo dos anos, os computadores cresceram em importância no suporte à colaboração. Anteriormente, utilizados apenas como ferramentas em processos já consolidados de colaboração, hoje eles também têm um papel de propulsor. Como objetivo fundamental, sistemas colaborativos visam atender totalmente uma colaboração, sob o ponto de vista do modelo 3C (comunicação, coordenação e cooperação), disponibilizando ferramentas e funcionalidades que auxiliam estas etapas. Contudo, novas tecnologias estão possibilitando cada vez mais que os domínios destes tipos de sistemas se expandam, atuando não somente nas três divisões clássicas da colaboração, mas também em etapas preliminares deste processo, como busca de usuários e recursos. Isto é possível quando estamos imergidos em um cenário de computação ubíqua, por exemplo. Fazendo uso das características que este ambiente provê, como mobilidade e ciência do contexto, é possível incrementar os processos de colaboração. Etapa primordial de uma colaboração, a busca e definiçã / Over the years, computers have grown in importance in supporting collaboration. Previously used solely as tools in already established processes, today, beyond that purpose, they also have a hole of fostering new and unforeseen forms of collaboration. As a fundamental objective, collaborative systems intended to meet the whole set of demands of a collaboration, what means, under the terms of the 3C Model, to provide tools and features that address communication, coordination and cooperation between parts. Nevertheless, new technologies are allowing to further increase the workspace of these systems, bringing collaboration support beyond the three traditional divisions stated at the 3C Model and towards acting in preliminary stages, such as the search for users and resources. This is possible, for instance, as we are immersed in a scenario of ubiquitous computing. Using the characteristics that this environment provides, such as mobility and context-awareness, it is possible to improve the processes of collab

In this dissertation work, we have investigated the main research thrust of decentralized coordination of workflows over web services. To address distributed workflow coordination, first we have developed “Web Coordination Bonds” as a capable set of dependency modeling primitives that enable each web service to manage its own dependencies. Web bond primitives are as powerful as extended Petri nets and have sufficient modeling and expressive capabilities to model workflow dependencies. We have designed and prototyped our “Web Service Coordination Management Middleware” (WSCMM) system that enhances current web services infrastructure to accommodate web bond enabled web services. Finally, based on core concepts of web coordination bonds and WSCMM, we have developed the “BondFlow” system that allows easy configuration distributed coordination of workflows. The footprint of the BonFlow runtime is 24KB and the additional third party software packages, SOAP client and XML parser, account for 115KB.

Η εξέλιξη των συνεργατικών εφαρμογών χαρακτηρίζεται από συνεχή δημιουργία και βελτίωση μηχανισμών που προάγουν και διευκολύνουν τη συνεργασία. Η ενημερότητα και η εστίαση προσοχής αναμφισβήτητα παίζουν κύριο ρόλο σε μία επιτυχημένη συνεργασία, γιατί υποδεικνύουν άμεσα αν ο χρήστης έχει γνώση και αντίληψη της κατάστασης των συνεργατών του. Στην εφαρμογή Synergo που αναπτύσσεται από την Ερευνητική Ομάδα Επικοινωνίας Ανθρώπου-Υπολογιστή (Human-Computer Interaction Group - HCI Group)υ τμήματος Ηλεκτρολόγων Μηχανικών και Τεχνολογίας Υπολογιστών της Πολυτεχνικής σχολής του πανεπιστημίου Πατρών και υποστηρίζει τη συνεργασία χρηστών κατά τη δημιουργία διαγραμμάτων σε κοινή επιφάνεια εργασίας, προστέθηκαν μηχανισμοί που βελτιώνουν την ενημερότητα και την εστίαση προσοχής του χρήστη. Αναπτυσσονται οι έννοιες της συνεργασίας μέσω υπολογιστή, των φαινομένων προσοχής και της ενημερότητας επιφάνειας εργασίας. Αφού γίνεται μία θεωρητική προσέγγιση στις παραπάνω έννοιες, γίνεται επισκόπιση του εργαλείου eye-tracker, περιγραφή της εφαρμογής Synergo και εξηγείται ο τρόπος προσαρμογής των συγκεκριμένων μηχανισμών. Αναλύεται λεπτομερώς το πειραματικό στάδιο και τα αποτελέσματά του και γίνεται αξιολόγηση και προτάσεις για δυνατές μελλοντικές τροποποιήσεις της εφαρμογής / The evolution of collaborative software is characterized by continuous creation and improvement of the mechanisms that promote and help communication. Awareness and attention shifting indisputably play the first role in a successful collaboration because they show directly if the user has the knowledge and the perception of his partners' state. In Synergo, a software that is developed from the Human-Computer Interaction Group - (HCI Group) of Electrical Engineering and Computer Technology department of Patra's University and supports the collaboration between users during the creation of conceptual graphs in a common workspace, mechanisms that improve user's awareness attention were developed.The concepts of computer supported cooperative work, attention phenomena and workspace awareness are explained. After a theoretical approach of the above concepts, eye tracker and Synergo software are being described and the adding of the mechanisms is being explained.The experimental stadium and it's results are described with every detail and the software is evaluated. There are also proposals for possible future improvements.

Στόχος της εργασίας είναι η μελέτη, ανάπτυξη και αξιολόγηση συνεργατικών εφαρμογών σε φορητές συσκευές. Για την μελέτη αυτή, αναπτύχθηκε ένα παιχνίδι διάχυτου υπολογισμού, το οποίο υποστηρίζει την χρήση του από πολλούς παίκτες ταυτόχρονα και μπορεί να παιχτεί παράλληλα σε διαφορετικές πόλεις από διαφορετικές ομάδες παικτών. Το παιχνίδι αυτό ανήκει σε ένα αναδυόμενο είδος παιχνιδιών που αναμιγνύουν την πραγματικότητα με τον εικονικό ψηφιακό κόσμο, χρησιμοποιώντας τον πραγματικό χώρο σαν το περιβάλλον του παιχνιδιού. Το παιχνίδι που αναπτύχθηκε εδώ χρησιμοποιεί σαν βασικά στοιχεία την μπλόφα, την παραπλάνηση και την ανάθεση ρόλων. Για την ανάπτυξή του ακολουθήθηκε ένα επαναληπτικό μοντέλο σχεδιασμού με την αξιολόγηση να παίρνει μέρος με διάφορες τεχνικές και μεθόδους στα διάφορα στάδια ανάπτυξης. Η υλοποίηση πραγματοποιήθηκε για κινητά τηλέφωνα με λειτουργικό σύστημα Android, μια επίσης καινούργια πλατφόρμα για φορητές συσκευές από την Google και την OHA. / The aim of this project is the design, development and evaluation of collaborative applications on mobile devices. For this study, a pervasive game was developed, which supports the use of it by many players simultaneously and can be played simultaneously in different cities by different groups of players. This game belongs to an emerging genre that mixes reality with the virtual digital world, using the real space as the gaming environment. The game was developed here uses the main elements of the bluff, deception and the assignment of roles. For its development an iterative design model was followed. The evaluation phase took place with various techniques and methods in different stages of development. The implementation was made for mobile phones running Android, also a new platform for mobile devices from Google and the OHA.

[pt] Em aplicações colaborativas distribuídas, o uso de repositórios centralizados para armazenamento dos dados e programas compartilhados compromete algumas características importantes desse tipo de aplicações, tais como tolerância a falhas, escalabilidade e autonomia local. Aplicações como Kazaa, Gnutella e Edutella exemplificam o emprego de computação ponto-a-ponto (P2P), que tem se mostrado uma alternativa interessante para solução dos problemas apontados acima, sem impor as restrições típicas de sistemas centralizados ou mesmo distribuídos do tipo mediadores e SGBDHs. Nesse trabalho apresentamos a arquitetura TEAM (Teamwork-support Environment Architectural Model) para gerência de workflows na web. Além de descrevermos os componentes e conectores da arquitetura, que se baseia em computação P2P, tratamos dos aspectos de modelagem de processos, gerência dos dados, metadados e das informações de controle de execução dos processos. Exploramos, também, a estratégia adotada para disseminação das consultas e mensagens encaminhadas aos pares da rede em ambientes baseados na arquitetura. Ilustramos o emprego da arquitetura TEAM em um estudo de caso em e-learning. / [en] In distributed collaborative applications, the use of centralized repositories for storing shared data and programs compromises some important characteristics of this type of applications, such as fault tolerance, scalability and local autonomy. Applications like Kazaa, Gnutella and Edutella exemplify the use of peer-to-peer computing, which is being considered an interesting alternative for the solution of the problems mentioned above, without imposing typical restrictions of centralized or even distributed systems such as mediators and HDBMSs. In this work we present the TEAM (Teamwork-support Environment Architectural Model) architecture for managing workflows in the Web. Besides describing the components and connectors of the architecture, which is based on P2P computing, we address the modelling of processes and management of data, metadata and execution control information.We also discuss the strategy adopted for queries dissemination and messages sent to peers in environments based on the architecture. We illustrate the application of TEAM in a case study in e-learning.

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Les réseaux de capteurs sans fil est une technologie nouvelle dont les applications s'étendent sur plusieurs domaines: militaire, scientifique, médicale, industriel, etc. La collaboration entre les noeuds capteurs, caractérisés par des capacités minimales en termes de capture, de transmission, de traitement et d'énergie, est une nécessité pour réaliser des tâches aussi complexes que la collecte des données, le pistage des objets mobiles, la surveillance des zones sensibles, etc. La contrainte matérielle sur le développement des ressources énergétiques des noeuds capteurs est persistante. D'où la nécessité de l'optimisation logicielle dans les différentes couches de la pile protocolaire et du système d'exploitation des noeuds. Dans cette thèse, nous approchons le problème d'optimisation d'énergie pour les applications collaboratives via les méthodes de sélection des capteurs basées sur la prédiction et la corrélation des données issues du réseau lui-même. Nous élaborons plusieurs méthodes pour conserver les ressources énergétiques du réseau en utilisant la prédiction comme un moyen pour anticiper les actions des noeuds et leurs rôles afin de minimiser le nombre des noeuds impliqués dans la tâche en question. Nous prenons l'application de pistage d'objets mobiles comme un cas d'étude. Ceci, après avoir dresser un état de l'art des différentes méthodes et approches récentes utilisées dans ce contexte. Nous formalisons le problème à l'aide d'un programme linéaire à variables binaires dans le but de trouver une solution générale exacte. Nous modélisons ainsi le problème de minimisation de la consommation d'énergie des réseaux de capteurs sans fil, déployé pour des applications de collecte de données soumis à la contrainte de précision de données, appelé EMDP. Nous montrons que ce problème est NP-Complet. D'où la nécessité de solutions heuristiques. Comme solution approchée, nous proposons un algorithme de clustering dynamique, appelé CORAD, qui adapte la topologie du réseau à la dynamique des données capturées afin d'optimiser la consommation d'énergie en exploitant la corrélation qui pourrait exister entre les noeuds. Toutes ces méthodes ont été implémentées et testées via des simulations afin de montrer leur efficacité. / Wireless Sensor Networks is an emerging technology enabled by the recent advances in Micro-Electro-Mechanical Systems, that led to design tiny wireless sensor nodes characterized by small capacities of sensing, data processing and communication. To accomplish complex tasks such as target tracking, data collection and zone surveillance, these nodes need to collaborate between each others to overcome the lack of battery capacity. Since the development of the batteries hardware is very slow, the optimization effort should be inevitably focused on the software layers of the protocol stack of the nodes and their operating systems. In this thesis, we investigated the energy problem in the context of collaborative applications and proposed an approach based on node selection using predictions and data correlations, to meet the application requirements in terms of energy-efficiency and quality of data. First, we surveyed almost all the recent approaches proposed in the literature that treat the problem of energy-efficiency of prediction-based target tracking schemes, in order to extract the relevant recommendations. Next, we proposed a dynamic clustering protocol based on an enhanced version of the Distributed Kalman Filter used as a prediction algorithm, to design an energy-efficient target tracking scheme. Our proposed scheme use these predictions to anticipate the actions of the nodes and their roles to minimize their number in the tasks. Based on our findings issued from the simulation data, we generalized our approach to any data collection scheme that uses a geographic-based clustering algorithm. We formulated the problem of energy minimization under data precision constraints using a binary integer linear program to find its exact solution in the general context. We validated the model and proved some of its fundamental properties. Finally and given the complexity of the problem, we proposed and evaluated a heuristic solution consisting of a correlation-based adaptive clustering algorithm for data collection. We showed that, by relaxing some constraints of the problem, our heuristic solution achieves an acceptable level of energy-efficiency while preserving the quality of data.