Software art refers to the production of software as art rather than the use of software to produce art. This thesis situates software arts practice in relation to a dialectical materialist tradition that focusses attention on the site of production and the contradictions within the relations of production. By making reference to post-Marxist theories, it is argued that antagonisms associated with traditional forms of labour have been extended to include the labour of machines and software. Therefore any analysis of the labour involved in making art must recognise the ways in which labour has become more immaterial, collective and communicative. In the case of software art, both the programmer and program can be seen to work, and produce artwork as software. Software art thereby holds the potential to make apparent the contradictions within the relations of production, as well as the potential to be programmed to act in a disruptive manner. That software art demonstrates emergent properties is substantiated by referring to both systems theory and dialectics, that share a common interest in dynamic processes and transformative agency. Consequently, the term 'software praxis' is proposed to characterise the combination of creative and critical activity embodied in transformative action. It is the assertion of this thesis that software art praxis can offer new critical forms of arts practice by embodying contradictions in the interplay between code and action. Contradiction is also embodied in the form this PhD submission takes: it is both a thesis in itself and, like software, ready to express its dialectical potential once executed. This thesis takes the conventional form of academic writing and a program script written in Perl. It collapses form and content by presenting a thesis _about_ software art that is simultaneously an example _of_ software art. Both the text and the program script can be interpreted and acted upon. The PhD submission includes references to a number of essays written during the registration period, and those that relate closely to the main argument are attached. Also included is documentation of three collaborative projects: the exhibition _Generator_, the publication _Notes Towards the Complete Works of Shakespeare_, and The UK Museum of Ordure's _Audio Library_ installation. These projects are represented by print-outs of web pages and video documentation on DVD. Although referred to in the text, the projects do not illustrate the thesis but embody its argument. Similarly, the text is not a linked narrative to these projects but an example of software art practice in itself. In form and content, the thesis expresses a dialectics of software art.

Τα συστήματα διαχείρισης περιεχομένου (Content Management Systems) χρησιμοποιούνται ευρέως στην κατασκευή εφαρμογών του παγκόσμιου ιστού. Το κυριότερο πλεονέκτημά τους είναι ότι άνθρωποι που δεν γνωρίζουν τις τεχνολογίες διαδικτύου μπορούν πολύ εύκολα μέσω διεπαφών να δημιουργήσουν αλλά και να συντηρήσουν την δική τους ιστοσελίδα.Ένα από τα δημοφιλέστερα CMS συστήματα είναι το Joomla. Το Joomla είναι open source οπότε και μπορεί κάποιος να το κατεβάσει δωρεάν ,να το χρησιμοποιήσει αλλά και να δει τον πηγαίο κώδικά του. Ξεχωρίζει από τα υπόλοιπα CMS συστήματα λόγο της απλότητας χειρισμού του και της μεγάλης κοινότητας χρηστών που το υποστηρίζουν. Η WebML είναι μια γλώσσα μοντελοποίησης διαδικτυακών εφαρμογών. Στόχος της είναι η παρουσίαση της δομής μιας τέτοιας εφαρμογής. Με την χρησιμοποίηση των WebML μονάδων ως επίπεδο αφαίρεσης μιας διαδικτυακής εφαρμογής είναι έυκολο να διακρίνουμε την δομή αλλά και τον τρόπο λειτουργίας της. Στην παρούσα διπλωματική εργασία χρησιμοποιείται η WebML για την μοντελοποίηση των ιστοσελίδων που παράγει το Joomla.H μοντελοποίηση αυτή μας βοηθάει να διακρίνουμε τα σχεδιαστικά πλεονεκτήματα αλλά και τις αδυναμίες που μπορεί να παρουσιάζει μια διαδικτυακή εφαρμογή δημιουργημένη με το συγκεκριμένο CMS. Η μοντελοποίηση γίνεται αυτόματα με ένα εργαλείο που έχει υλοποιηθεί στην γλώσσα προγραμματισμού Java και παρουσιάζει τα αποτελέσματα τόσο σε γραφική όσο και σε XML μορφή. / Content management systems (Content Management Systems) are widely used in the construction of Web applications. The main advantage is that people who are not familiar with internet technologies can very easily through interfaces create and maintain their own websites.One of the most popular CMS system is Joomla. Joomla is open source so anyone can download it free of charge, use it and see the source code. It distinguishes itself from other CMS systems because of the simplicity of use and the large user community that supports it. The WebML is a modeling language for web applications. Its aim is to present the structure of such an application. By using WebML units at an abstraction level in a web application it is easy to discern the structure and how it works. In this thesis WebML is used for modeling the web pages produced by the Joomla CMS. The modeling helps us to discern the design strengths and weaknesses that a web application created with this CMS may present. The modeling is done automatically with a tool that has been implemented in the Java programming language and presents the results both graphically and in XML format.

Σε αυτή την διπλωματική εργασία θα εξετάσουμε τα web services. Μια σχετικά νέα και αναπτυσσόμενη τεχνολογία. Θα δούμε τι ακριβώς είναι τα web services, θα εξετάσουμε την βασική αρχιτεκτονική τους και κάποια δομικά τους στοιχεία που είναι αρκετά συνήθη πλέον. Θα μιλήσουμε περί XML, WSDL, UDDI, ενώ θα επικεντρωθούμε στα SOAP Web Services. Στην συνέχεια θα τα εξετάσουμε από την πλευρά της ασφάλειας. Σίγουρα το θέμα της ασφάλειας των web εφαρμογών δεν είναι απλό ούτε μπορεί να αναλυθεί επαρκώς σε μερικές σελίδες μονάχα. Ο τομέας της ασφάλειας web εφαρμογών και web services είναι ένας τομέας ο οποίος εξελίσσεται δυναμικά. Πόσο μάλλον ο τομέας των web services, τα οποία εξελίσσονται και αυτά συνεχώς, οπότε αναμενόμενα όσο αναπτύσσονται νέες τεχνολογίες κι εξερευνούνται διαφορετικές προσεγγίσεις, συνεχώς ανακαλύπτονται νέες αδυναμίες απ’όπου μπορεί να παραβιαστεί το κάθε σύστημα, η κάθε εφαρμογή και υπηρεσία. Θα δημιουργήσουμε ένα SOAP web service σε PHP πλατφόρμα, μια ελάχιστα διαδεδομένη περίπτωση web service και θα εξετάσουμε τρόπους με τους οποίους μπορούμε να ενισχύσουμε την ασφάλεια και να προστατέψουμε το συγκεκριμένο service. Είναι μια περίπτωση στην οποία δεν μπορούμε να χρησιμοποιήσουμε τα διαδεδομένα πρωτόκολλα που έχουν τα web services για την ενίσχυση της ασφάλειάς τους, οπότε θα χρειαστεί να αναζητήσουμε δικούς μας “custom” τρόπους για την διαφύλαξη της ασφάλειας του service μας. / -

Σκοπός αυτής της εργασίας είναι η αναφορά και ανάλυση των υπαρχουσών τεχνολογιών με τις οποίες είναι δυνατή η κατασκευή ενός web service. Η γλώσσα XML καθώς και οι WSDL, UDDI και SOAP είναι οι βασικές τεχνολογίες που χρησιμοποιούνται για την κατασκευή των web services και αναλύονται λεπτομερώς με παραδείγματα, για την πλήρη κατανόησή τους / Τhe aim of this paper is to to analyse the current technology, we can construct a web service. XML, WSDL, UDDI and SOAP are the main tools we use to built a web service

Interactive Digital Storytelling (IDS) constitutes a research field that emerged from several areas of art, creation and computer science. It inquires technologies and possible artefacts that allow ‘highly-interactive’ experiences of digital worlds with compelling stories. However, the situation for story creators approaching ‘highly-interactive’ storytelling is complex. There is a gap between the available technology, which requires programming and prior knowledge in Artificial Intelligence, and established models of storytelling, which are too linear to have the potential to be highly interactive. This thesis reports on research that lays the ground for bridging this gap, leading to novel creation philosophies in future work. A design research process has been pursued, which centred on the suggestion of conceptual models, explaining a) process structures of interdisciplinary development, b) interactive story structures including the user of the interactive story system, and c) the positioning of human authors within semi-automated creative processes. By means of ‘implicit creation’, storytelling and modelling of simulated worlds are reconciled. The conceptual models are informed by exhaustive literature review in established neighbouring disciplines. These are a) creative principles in different storytelling domains, such as screenwriting, video game writing, role playing and improvisational theatre, b) narratological studies of story grammars and structures, and c) principles of designing interactive systems, in the areas of basic HCI design and models, discourse analysis in conversational systems, as well as game- and simulation design. In a case study of artefact building, the initial models have been put into practice, evaluated and extended. These artefacts are a) a conceived authoring tool (‘Scenejo’) for the creation of digital conversational stories, and b) the development of a serious game (‘The Killer Phrase Game’) as an application development. The study demonstrates how starting out from linear storytelling, iterative steps of ‘implicit creation’ can lead to more variability and interactivity in the designed interactive story. In the concrete case, the steps included abstraction of dialogues into conditional actions, and creating a dynamic world model of the conversation. This process and artefact can be used as a model illustrating non-programmer approaches to ‘implicit creation’ in a learning process. Research demonstrates that the field of Interactive Digital Storytelling still has to be further advanced until general creative principles can be fully established, which is a long-term endeavour, dependent upon environmental factors. It also requires further technological developments. The gap is not yet closed, but it can be better explained. The research results build groundwork for education of prospective authors. Concluding the thesis, IDS-specific creative principles have been proposed for evaluation in future work.

Οι εφαρμογές παγκόσμιου ιστού προσφέρουν ολοένα και περισσότερες, με υψηλό βαθμό πολυπλοκότητας, υπηρεσίες σε σχέση με τους πρώτους ιστότοπους που χρησιμοποιούνταν απλά και μόνο για την προβολή πληροφοριών. Λόγω της ολοένα αυξανόμενης πολυπλοκότητας των εφαρμογών αυτών, ο σχεδιασμός, η ανάπτυξη κι η συντηρησιμότητα μιας εφαρμογής παγκόσμιου ιστού προβάλλει ως μία από τις μεγαλύτερες προκλήσεις που καλείται να αντιμετωπίσει ο σχεδιαστής της. Η ερευνητική κοινότητα προκειμένου να αντιμετωπίσει την αυξανόμενη πολυπλοκότητα του σχεδιασμού εφαρμογών παγκόσμιου ιστού έχει προτείνει ένα πλήθος προσεγγίσεων και μεθόδων βασισμένων σε μοντέλα. Η δουλειά του σχεδιαστή εφαρμογών παγκόσμιου ιστού μπορεί να απλοποιηθεί ακόμα περισσότερο με την επαναχρησιμοποίηση της εμπειρίας άλλων σχεδιαστών εφαρμογών παγκόσμιου ιστού. Η επαναχρησιμοποίηση της εμπειρίας αυτής γίνεται με τη χρήση σχεδιαστικών προτύπων που ορίζονται από πεπειραμένους σχεδιαστές. Αν κατά το σχεδιασμό μιας εφαρμογής χρησιμοποιηθεί κάποια μέθοδος μοντελοποίησης σε συνδυασμό με ένα σύνολο σχεδιαστικών προτύπων, η τελική εφαρμογή θα είναι πιο αποδοτική και ποιοτική. Πολλές φορές όμως, κατά το σχεδιασμό και την ανάπτυξη μιας εφαρμογής παγκόσμιου ιστού δε λαμβάνεται υπόψη κάποια συγκεκριμένη μεθοδολογία μοντελοποίησης και ανάπτυξης. Ένα πλήθος μεθόδων αντίστροφης μηχανίκευσης έχει αναπτυχθεί για την ανάλυση, κατανόηση και μοντελοποίηση των αρχιτεκτονικών τέτοιου είδους εφαρμογών. Κατά τη μοντελοποίηση της αρχιτεκτονικής παραδοσιακών συστημάτων λογισμικού δεν εμφανίζεται η εσωτερική δομή του λειτουργικού συστήματος και του συστήματος παραθύρων (windowing system). Αντίστοιχα και στο πεδίο εφαρμογών παγκόσμιου ιστού δεν εμφανίζεται η εσωτερική δομή του εξυπηρετητή παγκόσμιου ιστού και του φυλλομετρητή. Τα αρχιτεκτονικά διαγράμματα των εφαρμογών παγκόσμιου ιστού πρέπει να δείχνουν τα κύρια συστατικά μιας εφαρμογής τα οποία συνδέονται μεταξύ τους για να υλοποιήσουν μεγάλες και σύνθετες εφαρμογές. Κύρια συστατικά μιας εφαρμογής θεωρούνται τα αντικείμενα του παγκόσμιου ιστού, οι πίνακες της βάσης δεδομένων και τα πολυμεσικά αντικείμενα. Στα πλαίσια αυτής της διπλωματικής εργασίας, αναλύσαμε το πιο δημοφιλές σύστημα διαχείρισης περιεχομένου (Content Management Systems – CMS) ανοιχτού κώδικα, το Joomla!. Συγκεκριμένα, εφαρμόσαμε αντίστροφη μηχανίκευση σε αυτό, ώστε να μπορέσουμε να μοντελοποιήσουμε την αρχιτεκτονική του. Για αυτό το σκοπό, αναπτύξαμε μια εφαρμογή που ερευνά τον HTML κώδικα όλων των σελίδων ενός ιστότοπου φτιαγμένου σε Joomla!, προκειμένου να γίνει αυτόματη εξαγωγή του μοντέλου του και όχι με το χέρι. Βασικός στόχος είναι να μπορέσουμε να αξιολογήσουμε το σχεδιασμό του μοντέλου του, αλλά και να παρέχουμε έναν αυτοματοποιημένο τρόπο για αξιολόγηση. Έτσι, θα μπορούν να προταθούν τρόποι αναδιάταξης, με στόχο τόσο την ευχρηστία όσο και την αποδοτικότητα χρήσης του συγκεκριμένου συστήματος διαχείρισης περιεχομένου. / Web Applications provide many services and they are not used just to display content, as it was the case for the first web sites. Due to the growing complexity, the design, development and maintenance of these applications has become one of the major challenges that the developer has to face. In an attempt to face this growing complexity, the research community has proposed a number of model based approaches and methods. The task of the hypertext architect may be further facilitated by reusing the experience of other hypertext architects. This reuse is achieved by means of design patterns that have been defined by experts. If, we make use of a modeling method in combination with design patterns when designing a web application, the final result will be more efficient and qualitative. Usually, due to the pressing market demands, the modeling methods or techniques are not applied during the degin and development of the web applications. A number of reverse engineering methods and tools have been proposed in order to analyze, comprehend and model the architectures of such applications. When the architecture of traditional software systems is modeled, the internal structure of the operating and windowing system does not appear. Similarly, in the field of web applications, the internal structure of the web server and browser does not appear. The architectural diagrams of web applications need to show the main components of an application, which are linked together in order to create large and complex applications. The main components of an application are the objects of the Web, the database tables and the multimedia objects. In this thesis, we analyzed the most popular open source Content Management System (CMS), Joomla!. More specifically, we applied reverse engineering to it, so that we could model its architecture. For this purpose, we developed an application which explores the HTML code of all web pages of a web site created by Joomla!, so that the extraction of its model will be done automatically and not manually. The main goal is to manage to evaluate the design of its model and to provide an automatic way for evaluation, as well. Thus, we can recommend ways to redeploy the system, so that usability and efficiency will be achieved, in the use of this content management system.

The need for modern enterprises and Web users to simply and rapidly develop and deliver platform-independent services to be accessed over the Web by the global community is growing. This is self-evident, when one considers the omnipresence of electronic services (e-services) on the Web. Accordingly, the Service-Oriented Architecture (SOA) is commonly considered as one of the de facto standards for the provisioning of heterogeneous business functionalities on the Web. As the basis for SOA, Web Services (WS) are commonly preferred, particularly because of their ability to facilitate the integration of heterogeneous systems. However, WS only focus on syntactic descriptions when describing the functional and behavioural aspects of services. This makes it a challenge for services to be automatically discovered, selected, composed, invoked, and executed – without any human intervention. Consequently, Semantic Web Services (SWS) are emerging to deal with such a challenge. SWS represent the convergence of Semantic Web (SW) and WS concepts, in order to enable Web services that can be automatically processed and understood by machines operating with limited or no user intervention. At present, research efforts within the SWS domain are mainly concentrated on semantic services automation aspects, such as discovery, matching, selection, composition, invocation, and execution. Moreover, extensive research has been conducted on the conceptual models and formal languages used in constructing semantic services. However, in terms of the engineering of semantic services, a number of challenges are still prevalent, as demonstrated by the lack of development and use of semantic services in real-world settings. The lack of development and use could be attributed to a number of challenges, such as complex semantic services enabling technologies, leading to a steep learning curve for service developers; lack of unified service platforms for guiding and supporting simple and rapid engineering of semantic services, and the limited integration of semantic technologies with mature service-oriented technologies. vi In addition, a combination of isolated software tools is normally used to engineer semantic services. This could, however, lead to undesirable consequences, such as prolonged service development times, high service development costs, lack of services re-use, and the lack of semantics interoperability, reliability, and re-usability. Furthermore, available software platforms do not support the creation of semantic services that are intelligent beyond the application of semantic descriptions, as envisaged for the next generation of services, where the connection of knowledge is of core importance. In addressing some of the challenges highlighted, this research study adopted a qualitative research approach with the main focus on conceptual modelling. The main contribution of this study is thus a framework called iSemServ to simplify and accelerate the process of engineering intelligent semantic services. The framework has been modelled and developed, based on the principles of simplicity, rapidity, and intelligence. The key contributions of the proposed framework are: (1) An end-to-end and unified approach of engineering intelligent semantic services, thereby enabling service engineers to use one platform to realize all the modules comprising such services; (2) proposal of a model-driven approach that enables the average and expert service engineers to focus on developing intelligent semantic services in a structured, extensible, and platform-independent manner. Thereby increasing developers’ productivity and minimizing development and maintenance costs; (3) complexity hiding through the exploitation of template and rule-based automatic code generators, supporting different service architectural styles and semantic models; and (4) intelligence wrapping of services at message and knowledge levels, for the purposes of automatically processing semantic service requests, responses and reasoning over domain ontologies and semantic descriptions by keeping user intervention at a minimum. The framework was designed by following a model-driven approach and implemented using the Eclipse platform. It was evaluated using practical use case scenarios, comparative analysis, and performance and scalability experiments. In conclusion, the iSemServ framework is considered appropriate for dealing with the complexities and restrictions involved in engineering intelligent semantic services, especially because the amount of time required to generate intelligent semantic vii services using the proposed framework is smaller compared with the time that the service engineer would need to manually generate all the different artefacts comprising an intelligent semantic service. Keywords: Intelligent semantic services, Web services, Ontologies, Intelligent agents, Service engineering, Model-driven techniques, iSemServ framework. / Computing / D. Phil. (Computer science)

Οι συνεχείς εξελίξεις στο χώρο του Διαδικτύου έχουν επιφέρει σημαντικές αλλαγές στο χώρο της εκπαιδευτικής τεχνολογίας. Καθοριστικό ρόλο προς αυτήν την κατεύθυνση έχει διαδραματίσει το Web 2.0, μια δεύτερη γενιά διαδικτυακών υπηρεσιών βασισμένων κατ' εξοχήν στη συμμετοχή του κοινού και τη συνεργασία των χρηστών. Τα τελευταία χρόνια πολλές από τις τεχνολογίες του Web 2.0 έχουν αρχίσει να αξιοποιούνται στο χώρο της εκπαίδευσης. Παρουσιάζεται μια εκτενής έρευνα σχετικά με τη χρήση εργαλείων στην εκπαίδευση και γίνεται μια προσπάθεια αξιολόγησης της συνεισφοράς τους στην εκπαιδευτική διαδικασία. Για την αποτίμηση της αποτελεσματικότητας και καταλληλότητας των εργαλείων στη εκπαίδευση, σχεδιάστηκε, υλοποιήθηκε και αξιολογήθηκε μια πιλοτική μελέτη στη Δευτεροβάθμια Εκπαίδευση. Επιλέχθηκε το μάθημα της Φυσικής για την Α' Λυκείου και μαθητές από το Πρότυπο Πειραματικό Λύκειο Πανεπιστημίου Πατρών. Συγκεκριμένα η μελέτη παρουσιάζει μια εφαρμογή εκπαιδευτικής πλατφόρμας, Ασύγχρονης Τηλεκπαίδευσης που δημιουργήθηκε για το σκοπό αυτό, αφού προστέθηκε στην γνωστή πλατφόρμα Open eClass από την GUnet το υποσύστημα Ιστολόγιο. Η εφαρμογή ονομάστηκε ePhysics και συνδυάζει εργαλεία όπως το Ιστολόγιο, το Σύστημα Wiki, οι Σύνδεσμοι, το Twiducate κ.α. Η εφαρμογή αυτή χρησιμοποιήθηκε στα πλαίσια μιας αυθεντικής εκπαιδευτικής δραστηριότητας για να υποστηρίξει τη συνεργασία των μαθητών. Τα αποτελέσματα της έρευνας έδειξαν πως στα πλαίσια μιας σωστής σχεδίασης, το ePhysics μπορεί να χρησιμοποιηθεί με επιτυχία για την υποστήριξη της συνεργασίας σε πραγματικές εκπαιδευτικές συνθήκες και να αποτελέσει μια ευέλικτη και αποδοτική μορφή συνεργατικής μάθησης στη Δευτεροβάθμια Εκπαίδευση. / The constant changes of the Internet have resulted in significant changes in educational technology. A decisive part towards this evolution is Web 2.0, a new generation of web services based on the principle of participation and collaboration of users. During the last years, many Web 2.0 technologies are utilised in various aspects of education. Moreover, we present a detailed study of the integration of Wiki-based tools in education and attempt to evaluate their contribution in the educational activity. For the assessment of the suitability and effectiveness of web 2.0 - tools in education, we have designed, implemented, and evaluated a pilot case study for Secondary Education. We have chosen the course of “Physics” for the A Grade of Lyceum and students from the Experimental Lyceum of the University of Patras. More specifically, the study presents an implementation of educational platform, Asynchronous eLearning that was designed for this purpose, after it was added in the also known platform Open eClass by GUnet the subsystem Blog. Our implementation was named ePhysics and it combines several tools such as Blog, Wikis, Links, Twiducate etc. This implementation was used in an authentic educational activity in order to support the collaboration between the students. The results of this study have proved that, under a correct design, ePhysics can be used with great success for supporting real educational activities and is a very flexible and efficient form of collaborative learning in Secondary Education.

The need for modern enterprises and Web users to simply and rapidly develop and deliver platform-independent services to be accessed over the Web by the global community is growing. This is self-evident, when one considers the omnipresence of electronic services (e-services) on the Web. Accordingly, the Service-Oriented Architecture (SOA) is commonly considered as one of the de facto standards for the provisioning of heterogeneous business functionalities on the Web. As the basis for SOA, Web Services (WS) are commonly preferred, particularly because of their ability to facilitate the integration of heterogeneous systems. However, WS only focus on syntactic descriptions when describing the functional and behavioural aspects of services. This makes it a challenge for services to be automatically discovered, selected, composed, invoked, and executed – without any human intervention. Consequently, Semantic Web Services (SWS) are emerging to deal with such a challenge. SWS represent the convergence of Semantic Web (SW) and WS concepts, in order to enable Web services that can be automatically processed and understood by machines operating with limited or no user intervention. At present, research efforts within the SWS domain are mainly concentrated on semantic services automation aspects, such as discovery, matching, selection, composition, invocation, and execution. Moreover, extensive research has been conducted on the conceptual models and formal languages used in constructing semantic services. However, in terms of the engineering of semantic services, a number of challenges are still prevalent, as demonstrated by the lack of development and use of semantic services in real-world settings. The lack of development and use could be attributed to a number of challenges, such as complex semantic services enabling technologies, leading to a steep learning curve for service developers; lack of unified service platforms for guiding and supporting simple and rapid engineering of semantic services, and the limited integration of semantic technologies with mature service-oriented technologies. vi In addition, a combination of isolated software tools is normally used to engineer semantic services. This could, however, lead to undesirable consequences, such as prolonged service development times, high service development costs, lack of services re-use, and the lack of semantics interoperability, reliability, and re-usability. Furthermore, available software platforms do not support the creation of semantic services that are intelligent beyond the application of semantic descriptions, as envisaged for the next generation of services, where the connection of knowledge is of core importance. In addressing some of the challenges highlighted, this research study adopted a qualitative research approach with the main focus on conceptual modelling. The main contribution of this study is thus a framework called iSemServ to simplify and accelerate the process of engineering intelligent semantic services. The framework has been modelled and developed, based on the principles of simplicity, rapidity, and intelligence. The key contributions of the proposed framework are: (1) An end-to-end and unified approach of engineering intelligent semantic services, thereby enabling service engineers to use one platform to realize all the modules comprising such services; (2) proposal of a model-driven approach that enables the average and expert service engineers to focus on developing intelligent semantic services in a structured, extensible, and platform-independent manner. Thereby increasing developers’ productivity and minimizing development and maintenance costs; (3) complexity hiding through the exploitation of template and rule-based automatic code generators, supporting different service architectural styles and semantic models; and (4) intelligence wrapping of services at message and knowledge levels, for the purposes of automatically processing semantic service requests, responses and reasoning over domain ontologies and semantic descriptions by keeping user intervention at a minimum. The framework was designed by following a model-driven approach and implemented using the Eclipse platform. It was evaluated using practical use case scenarios, comparative analysis, and performance and scalability experiments. In conclusion, the iSemServ framework is considered appropriate for dealing with the complexities and restrictions involved in engineering intelligent semantic services, especially because the amount of time required to generate intelligent semantic vii services using the proposed framework is smaller compared with the time that the service engineer would need to manually generate all the different artefacts comprising an intelligent semantic service. Keywords: Intelligent semantic services, Web services, Ontologies, Intelligent agents, Service engineering, Model-driven techniques, iSemServ framework. / Computing / D. Phil. (Computer science)

Le but de cette thèse est de dégager un cadre sémantique formel approprié supportant l'interopérabilité dedifférents formalismes déjà utilisés pour décrire et déployer un service Web. En d’autres termes, nouscontribuons au développement d’un formalisme mathématique rigoureux permettant de décrire un service Webcomplexe susceptible de changer pendant l’exécution et de coordonner avec les autres services de façonadaptative. Pour atteindre cet objectif, les étapes de description, de sélection et de composition ont constitué lestrois majeures problématiques étudiées dans cette thèse.Pour ce faire, nous avons proposé dans un premier temps, à travers l’utilisation du cadre sémantique formel K lelangage K-WSDL; un langage de description de services Web doté d’une sémantique opérationnelle en terme derègles de réécriture qui peut être exécutable et analysable sous Maude. Nous avons introduit, dans un secondtemps, l’approche WS-Sim basée sur la théorie des catégories qui évalue l’équivalence comportementale entreservices en représentant chaque service par une catégorie et en établissant des liens formels (foncteur) entre elles.Enfin, nous avons présenté le modèle RMop-ECATNet (Refined Meta Open ECATNet ) : un modèle dédié à laspécification formelle de la composition des services Web et fruit du raffinement du modèle Mop-ECATNetproposé par [LB14]. Nous avons étendu et enrichi ce dernier aux trois niveaux : structurel, comportemental etimplémentation. / The aim of this thesis is to provide a suitable formal semantic framework that supports interoperability ofdifferent formalisms already used to describe and deploy a Web service. In other words, we contribute to thedevelopment of a rigorous mathematical formalism to describe a complex Web service that may change duringexecution and coordinate with other services adaptively. To achieve this goal, the steps of description, selectionand composition constitute the three major issues studied in this thesis.We proposed so, initially, through the use of the K semantic framework the K-WSDL : a Web servicesdescription language endowed with an operational semantics in terms of rewriting rules which can be executedand analyzed in Maude. We introduced, in a second step, WS-Sim, a new approach based on the category theorywhich evaluates the behavioral equivalence between services by representing each service by a category and byestablishing formal links (functor) between them. Finally, we present RMop-ECATNet (Refined Meta OpenECATNet): a formal model for the specification of services composition. product of the refinement of the Mop-ECATNets model, introduced initially by [LB14]. We extended and enriched this model at three distinct levels:at the structural, behavioural level and implementation levels.