In grids, delegation is a key facility that can be used to authenticate and authorize requests on behalf of disconnected users. In current grid systems,delegation is either performed dynamically, in an unrestricted manner, or by a secure but static method. Unfortunately, the former compromises security and the latter cannot satisfy the requirements of dynamic grid application execution. Therefore, development of a delegation framework that enables a restricted and flexible delegation mechanism becomes increasingly urgent as grids are adopted by new communities and grow in size. The main barriers in development of such a mechanism are the requirements for dynamic execution of grid applications, which make it difficult to anticipate required access rights for completing tasks in advance. Another significant architectural requirement in grids is federated security and trust. A considerable barrier to achieving this is cross-organizational authentication and identification. Organizations participating in Virtual Organizations (VOs) may use different security infrastructures that implement different protocols for authentication and identification; thus, there exists a need to provide an architectural mechanism for lightweight, rapid and interoperable translation of security credentials from an original format to a format understandable by recipients. This thesis contributes the development of a delegation framework that utilizes a mechanism for determining and acquiring only required rights and credentials for completing a task, when they are needed. This is what we call an on-demand delegation framework that realizes a bottom-up delegation model and provides a just-in-time acquisition of rights for restricted and dynamic delegation. In this thesis, we further contribute the development of a credential mapping mechanism using off-the-shelf standards and technologies. This mechanism provides support for an on-the-fly exchange of different types of security credentials used by the security mechanisms of existing grids. / QC 20100622

Environmental Health and Safety (EHS) departments in many organizations are faced with two interrelated problems which limit their ability to make accurate decisions based on quality data. First, many EHS departments follow a reactive business management model and need to work towards a proactive continuous improvement model to better manage EHS. The second is a lack of data integration and interoperability between the numerous different EHS data sources and systems. EHS departments are challenged with managing large quantities of data generated through tracking and monitoring programs to continuously improve EHS performance. EHS data can be in many forms paper, digital files, spreadsheets, images, relational databases and proprietary software applications. EHS data have strong spatial relationships, which makes the use of Geographical Information Systems (GIS) a very cost effective and feasible solution for integrating and managing EHS data. This thesis will outline how GIS brings to EHS the advantages of traditional IT methods with the added benefit of spatial analytical operations such as map overlay, relationships and querying, and informative visual presentation through maps, floor plans, and imagery through the implementation of a GIS database for EHS called GeoSpatial Environmental Health and Safety (GEO-EHS).

Environmental Health and Safety (EHS) departments in many organizations are faced with two interrelated problems which limit their ability to make accurate decisions based on quality data. First, many EHS departments follow a reactive business management model and need to work towards a proactive continuous improvement model to better manage EHS. The second is a lack of data integration and interoperability between the numerous different EHS data sources and systems. EHS departments are challenged with managing large quantities of data generated through tracking and monitoring programs to continuously improve EHS performance. EHS data can be in many forms paper, digital files, spreadsheets, images, relational databases and proprietary software applications. EHS data have strong spatial relationships, which makes the use of Geographical Information Systems (GIS) a very cost effective and feasible solution for integrating and managing EHS data. This thesis will outline how GIS brings to EHS the advantages of traditional IT methods with the added benefit of spatial analytical operations such as map overlay, relationships and querying, and informative visual presentation through maps, floor plans, and imagery through the implementation of a GIS database for EHS called GeoSpatial Environmental Health and Safety (GEO-EHS).

Conformance to standards and interoperability is a major challenge of today`s applications in all domains. Several standards have been developed and some are still under development to address the various layers in the interoperability stack. Conformance and interoperability testing involves checking whether the applications conform to the standards so that they can interoperate with other conformant systems. Only through testing, correct information exchange among applications can be guaranteed. National Health Information System (NHIS) of Turkey aims to provide a nation-wide infrastructure for sharing Electronic Health Records (EHRs). In order to guarantee the interoperability, the Ministry of Health (MoH), Turkey, developed an Implementation/Integration/Interoperability Profile based on HL7 standards. TestBATN - Testing Business Process, Application, Transport and Network Layers - is a domain and standards independent set of tools which can be used to test all of the layers of the interoperability stack, namely, the Communication Layer, Document Content Layer and the Business Process Layer. In this thesis work, the requirements for conformance and interoperability testing of the NHIS are analyzed, a testing approach is designated, test cases for several NHIS services are developed and deployed and a test execution control and monitoring environment within TestBATN is designed and implemented through the identified testing requirements. The work presented in this thesis is part of the TestBATN system supported by the T&Uuml / BiTAK TEYDEB Project No: 7070191 in addition by the Ministry of Health, Turkey.

<p>In this thesis we will identify which are the desired features and functionalities for implementing a system capable of acting as an information bridge for content available in the “wired” Internet to be delivered to mobile devices. We will also explore how to design and build such a system based on the specifications within parts of the MUSIS project. The MUSIS’ system development is used as a base of the work described in this thesis and the experiences from those efforts are used in order to design a system with more focus on data portability and media migration.</p><p>During the development of the MUSIS platform, problems related to system upgrading, i.e. adding new ad-hoc functionalities were discovered. Due to the fact that a user-centred design approach was taken, this was essential in the project. To solve some of these issues, we propose a new component-based system with a high level of scalability and re-usability. We name this system Collect, Convert and Send, CCS. The system shall be seen as a base that can be used as a core system for different projects where interoperability of content between different platforms, devices or systems is important.</p><p>The implementation of the system is based on the use cases and those theoretical aspects and ideas related to component software, interoperability, media migration and metadata in a Web service context. The results of our efforts give some indications that the use of component software gives a foundation for a service-oriented architecture.</p>

Στην εν λόγω εργασία, έγινε μια προσπάθεια καταγραφής του τεχνολογικού τοπίου της τηλεπικοινωνιακής αγοράς, με έμφαση την διαλειτουργικότητα μεταξύ των Δικτύων Κινητής Τηλεφωνίας και των Ασύρματων Δικτύων Δεδομένων και των σχετικών αλλαγών που έχει επιφέρει αυτή η διαλειτουργικότητα, τόσο στις παρεχόμενες υπηρεσίες, όσο και στα εφαρμοζόμενα επιχειρηματικά μοντέλα από πλευράς εταιρειών της συγκεκριμένης αγοράς. Στα πλαίσια αυτής της προσπάθειας, χρειάστηκε να πραγματοποιηθεί μια λεπτομερής καταγραφή των τεχνολογικών εξελίξεων, σε επίπεδο τεχνικών προδιαγραφών και προτύπων, στις παραπάνω δύο κατηγορίες δικτύων, ώστε να καταλήξουμε σε εκείνα τα πρότυπα που πλέον μπορούν να οδηγήσουν στην υλοποίηση δικτύων τα οποία θα χαρακτηρίζονται από τα παρακάτω: • θα είναι ενοποιημένα ώστε οι διαφορετικές τεχνολογικές πλατφόρμες των εταιρειών να λειτουργούν απρόσκοπτα, • θα χαρακτηρίζονται από χαμηλό κόστος, • ο τελικός χρήστης θα μπορεί να είναι συνεχώς συνδεδεμένος με κάποιο δίκτυο ασύρματης πρόσβασης και να απολαμβάνει τις υπηρεσίες που επιθυμεί, οποτεδήποτε και οπουδήποτε. Η δομή της διπλωματικής εργασίας ακολουθεί τον προαναφερθέντα τρόπο σκέψης. Στο 1ο Κεφάλαιο γίνεται μια σύντομη παρουσίαση του στόχου σε επίπεδο τεχνολογιών αλλά και υπηρεσιών, δηλαδή των αναμενόμενων αποτελεσμάτων αυτών των δικτύων νέας γενιάς, στα οποία έχουμε συνηθίσει να αναφερόμαστε ως δίκτυα 4G (4th Generation) ή δίκτυα B3G (Beyond 3G) ή τέλος ως All – IP ασύρματα δίκτυα. Στο 2ο Κεφάλαιο, γίνεται μια λεπτομερής παρουσίαση των Δικτύων Κινητής Τηλεφωνίας από τις πρώτες τους εκδοχές (1G) έως τις πλέον σύγχρονες (3.5G) που έχουν εμφανιστεί μέχρι σήμερα. Αναλύονται τόσο οι γενιές των δικτύων όσο και τα χρησιμοποιούμενα πρότυπα, σε επίπεδο αρχιτεκτονικής όσο και σε επίπεδο πρωτοκόλλων. Στη συνέχεια του κεφαλαίου υπάρχει η τεχνική περιγραφή των επικρατέστερων δικτύων κινητής τηλεφωνίας, σήμερα, δηλαδή των GSM, GPRS και UMTS, ενώ στο τέλος του κεφαλαίου υπάρχει μια σύντομη περιγραφή της διαδικασίας intersystem handover μεταξύ των GSM και UMTS. Στο 3ο Κεφάλαιο, περνάμε πλέον στα Ασύρματα Δίκτυα Δεδομένων. Γίνεται μια εκτενής περιγραφή των προτύπων που έχουν καθοριστεί και συγκεκριμένα στα πρότυπα IEEE 802.15 Wireless Personal Area Networks (WPANs) με κυριότερους εκφραστές τα δίκτυα βασιζόμενα σε Bluetooth και IrDA, το πρότυπο IEEE 802.11 Wireless Local Area Networks (WLANs) με σημαντικότερος εκπροσώπους τα WiFi και HyperLan/2, το πρότυπο IEEE 802.16 Wireless Metropolitan Area Networks (WMANs) ή αλλιώς γνωστότερο ως WiMAX και τέλος το πρότυπο IEEE 802.20 Wireless Wide Area Networks (WWANs) ή διαφορετικά Mobile Broadband Wireless Access (MWBA) το οποίο είναι υπό διερεύνηση ακόμα και φιλοδοξεί να αποτελέσει το ασύρματο ανάλογο της τεχνολογίας xDSL, καθώς θα προσφέρει ασύρματες ευρυζωνικές υπηρεσίες. Στο 4ο Κεφάλαιο παρουσιάζονται μεθοδολογίες υλοποίησης του integration μεταξύ δικτύων των δύο κατηγοριών και συγκεκριμένα παραδείγματα διαλειτουργικότητας, όπως μεταξύ GPRS ή UMTS και WLANs ή μεταξύ UMTS και WiMAX. Γίνεται εκτενής συζήτηση γύρω από τα προβλήματα που θα πρέπει να αντιμετωπιστούν, όπως η εξασφάλιση ανεκτού επιπέδου QoS, οι μηχανισμοί για handover μεταξύ των δικτύων, η διαχείριση της κινητικότητας των χρηστών και των τερματικών και δίνονται παραδείγματα δημιουργίας ενοποιημένων δικτύων, τόσο με τη τεχνική της χαλαρής όσο και με την τεχνική της ισχυρής ζεύξης. Στο τελευταίο τμήμα του Κεφαλαίου, γίνεται μια εκτενής αναφορά στις αρχιτεκτονικές διασύνδεσης ετερογενών δικτύων με IP δίκτυα κορμού, τα γνωστά All – IP networks. Ιδιαίτερη έμφαση δίνεται στους μηχανισμούς πραγματοποίησης των handovers βάσει πολιτικών (policy based) και η χρήση τεχνικών για micromobility και macromobility σε σχέση με την κινητικότητα των τερματικών. Το 5ο Κεφάλαιο αφορά τις εφαρμογές και υλοποιήσεις ασυρμάτων δικτύων δεδομένων στον Ελληνικό χώρο, στα πλαίσια του Επιχειρησιακού Προγράμματος «Κοινωνία της Πληροφορίας» και πιο συγκεκριμένα τα «Εξοπλισμός και δικτύωση σε όλες τις βαθμίδες της εκπαίδευσης», «Ασύρματα Ευρυζωνικά Δίκτυα ΟΤΑ»και «Μητροπολιτικά Ευρυζωνικά Δίκτυα Οπτικών Ινών ΟΤΑ» και ουσιαστικά αποτελούν παραδείγματα και υλοποιήσεις διασύνδεσης WiFi, WiMAX και IP backbone δικτύων όπως το ΣΥΖΕΥΞΙΣ με δυνατότητες για παροχή VoIP. / In this thesis, an effort of presenting the technological landscape of the telecommunication market takes place, with focus on the interoperability between the Mobile Telephony Networks and the Wireless Data Networks and the relative changes that have evolved through this interoperability, both regarding the provided services and the applied business models by the enterprises of the specific market. Within the frames of this effort, a detailed recording of technological developments is realised, in terms of technical specifications and standards, in the two aforementioned categories of networks, so as to conclude to those standards that are utilized by the next generation networks (4G) which will be: • Networks that will be unified so as the different technological platforms will function smoothly. • Networks that will be characterized by low cost of deployment. • The end user will be continuously connected with a wireless access network, enjoying the preferred services anywhere and anytime. The master thesis structure follows the aforementioned methodology. The 1st Chapter includes a short presentation of expected results, both in terms of technologies and services for next generation networks, which we usually refer to as 4G networks (4th Generation) or B3G networks (Beyond 3G) or finally as All - IP wireless networks (AIPN). In the 2nd Chapter, a detailed presentation of Mobile Telephony Networks takes place, from their first versions (1G) until the most modern (3.5G) that have been presented up to today. The analysis includes both the various generations of networks and the used standards, in terms of modulation and multiplexing techniques. The rest of the chapter focuses on the technical description of the prevailing networks, GSM, GPRS and UMTS, while the chapter ends with a short description of intersystem handover processes between GSM and UMTS. Τhe 3rd Chapter, includes an extensive description of the Wireless Data Networks standards such as: IEEE 802.15 Wireless Personal Area Networks (WPANs) with main representatives networks based on Bluetooth and IrDA, standard IEEE 802.11 Wireless Local Area Networks (WLANs) mainly represented by WiFi and HyperLan/2, IEEE 802.16 Wireless Metropolitan Area Networks (WMANs) standard, widely known as WiMax and finally the IEEE 802.20 Wireless Wide Area Networks (WWANs) standard, namely Mobile Broadband Wireless Access (MWBA) that is still under development and aspires to constitutes the wireless version of the xDSL technology, since it aims to provide wireless broadband services. In the 4th Chapter methodologies for integrating the two types of networks, are presented along with examples of interoperability between GPRS / UMTS and WLANs or between UMTS and WiMAX. Extensive discussion around the problems that should be faced, as the guarantee of bearable QoS level, the mechanisms for handover between the networks and the management of mobility of users and terminals, is held. Moreover, examples of integrated networks with both loose and tight coupling methodologies are presented. The last section of the chapter concerns a detailed description of architectures for interconnecting heterogeneous wireless networks over IP – based backhaul networks, namely All – IP networks, with special focus on policy based handover mechanisms and techniques for managing micromobility and macromobility issues. The 5th Chapter concerns the changes taking place in the telecommunications market deriving from the technological progress in the subject of heterogeneous wireless networks interconnection. New service packets are created, as a result of new business plans that are drawn up by the big telecommunications organizations. Finally, we present the developments in the Greek market and subsidised projects from Information Society AE, via which wireless networks have been materialised, with aim to promote Broadband Services.

Nowadays, there is an increasing need for interaction in business community. In such context, organizations collaborate with each other in order to achieve a common goal. In such environment, each organization has to design and implement an interoperability security policy. This policy has two objectives: (i) it specifies the information or the resources to be shared during the collaboration and (ii) it define the privileges of the organizations' users. To guarantee a certain level of security, it is mandatory to check whether the organizations' information systems behave as required by the interoperability security policy. In this thesis we propose a method to test the behavior of a system with respect to its interoperability security policies. Our methodology is based on two approaches: active testing approach and passive testing approach. We found that these two approaches are complementary when checking contextual interoperability security policies. Let us mention that a security policy is said to be contextual if the activation of each security rule is constrained with conditions. The active testing consists in generating a set of test cases from a formal model. Thus, we first propose a method to integrate the interoperability security policies in a formal model. This model specifies the functional behavior of an organization. The functional model is represented using the Extended Finite Automata formalism, whereas the interoperability security policies are specified using OrBAC model and its extension O2O. In addition, we propose a model checking based method to check whether the behavior of a model respects some interoperability security policies. To generate the test cases, we used a dedicated tool developed in our department. The tool allows generating abstract test cases expressed in the TTCN notation to facilitate its portability. In passive testing approach, we specify the interoperability policy, that the system under test has to respect, with Linear Temporal logics. We analyze then the collected traces of the system execution in order to deduce a verdict on their conformity with respect to the interoperability policy. Finally, we show the applicability of our methods though a hospital network case study. This application allows to demonstrate the effectiveness and reliability of the proposed approaches

The main scientific problems investigated in this work deal with the creation of flexible open source e-Learning content and services system (referred here as Digital Library of Educational resources and services – DLE) providing learning customisation possibilities for its users. Standards and interoperability are key factors in the success of the introduction of such kind of DLEs, and therefore the main research object of the work is investigation and proposal of interoperability guidelines for DLE components. The main problem is not the identification of suitable standards and specifications, but the adoption of these standards and specifications and their application in e-Learning practice. Approaches concerning LOM Standard Application Profiles (APs) and curricula mapping are the main topics created and investigated here because they could provide more quick and convenient LOs search possibilities in the repositories for the users. Another key factor is quality of DLE systems, and therefore one more research object of the work is the effectiveness of methods of DLE components evaluation. DLE components’ complex evaluation tools suitable for systems based on flexible approach have been created. These tools should include a number of criteria to evaluate LOs reusability level and VLEs adaptation capabilities. Practice of flexible DLE software creation and development for Lithuanian primary, secondary and vocational education based of flexible approach is presented in more... [to full text] / Disertacijoje nagrinėjamos lanksčios atvirosios el. mokymosi turinio ir paslaugų sistemos (t. y. skaitmeninės švietimo išteklių ir paslaugų bibliotekos, angl. Digital Library of Educational Resources and Services) kūrimo bendrajam lavinimui ir profesiniam mokymui mokslinės problemos. Nagrinėjama skaitmeninės švietimo išteklių ir paslaugų bibliotekos (toliau – skaitmeninės bibliotekos) schema ir reikalavimai. Pagrindinis dėmesys skiriamas bibliotekos lankstumui, t. y. biblioteka turi teikti naudotojams individualizuoto mokymosi galimybes. Skaitmeninės bibliotekos sudedamųjų dalių suderinamumas (sąveikos geba, arba sąveikumas, angl. Interoperability) ir standartai yra esminiai bibliotekos funkcionavimo veiksniai, todėl pagrindinis disertacijos tikslas yra bibliotekos sudedamųjų dalių sąveikumo rekomendacijų kūrimas. Sprendžiami uždaviniai: standartų parinkimas, jų tinkamumas, adaptavimas ir taikymas švietimui. Pagrindinis dėmesys skiriamas mokymosi objektų (MO, angl. Learning Objects) metaduomenų standarto (LOM – angl. Leaning Objects Metadata) taikymo modeliui tobulinti ir bendrųjų programų sąryšiui su MO. Daug dėmesio skiriama skaitmeninės bibliotekos sudedamųjų dalių kokybei vertinti, todėl bibliotekos sudedamųjų dalių kompleksinių vertinimo kriterijų, pagrįstų bibliotekos lankstumo ir sudedamųjų dalių sąveikumo rekomendacijomis, kūrimas taip pat yra darbo tikslas.

Disertacijoje nagrinėjamos lanksčios atvirosios el. mokymosi turinio ir paslaugų sistemos (t. y. skaitmeninės švietimo išteklių ir paslaugų bibliotekos, angl. Digital Library of Educational Resources and Services) kūrimo bendrajam lavinimui ir profesiniam mokymui mokslinės problemos. Nagrinėjama skaitmeninės švietimo išteklių ir paslaugų bibliotekos (toliau – skaitmeninės bibliotekos) schema ir reikalavimai. Pagrindinis dėmesys skiriamas bibliotekos lankstumui, t. y. biblioteka turi teikti naudotojams individualizuoto mokymosi galimybes. Skaitmeninės bibliotekos sudedamųjų dalių suderinamumas (sąveikos geba, arba sąveikumas, angl. Interoperability) ir standartai yra esminiai bibliotekos funkcionavimo veiksniai, todėl pagrindinis disertacijos tikslas yra bibliotekos sudedamųjų dalių sąveikumo rekomendacijų kūrimas. Sprendžiami uždaviniai: standartų parinkimas, jų tinkamumas, adaptavimas ir taikymas švietimui. Pagrindinis dėmesys skiriamas mokymosi objektų (MO, angl. Learning Objects) metaduomenų standarto (LOM – angl. Leaning Objects Metadata) taikymo modeliui tobulinti ir bendrųjų programų sąryšiui su MO. Daug dėmesio skiriama skaitmeninės bibliotekos sudedamųjų dalių kokybei vertinti, todėl bibliotekos sudedamųjų dalių kompleksinių vertinimo kriterijų, pagrįstų bibliotekos lankstumo ir sudedamųjų dalių sąveikumo rekomendacijomis, kūrimas taip pat yra darbo tikslas. / The main scientific problems investigated in this work deal with the creation of flexible open source e-Learning content and services system (referred here as Digital Library of Educational resources and services – DLE) providing learning customisation possibilities for its users. Standards and interoperability are key factors in the success of the introduction of such kind of DLEs, and therefore the main research object of the work is investigation and proposal of interoperability guidelines for DLE components. The main problem is not the identification of suitable standards and specifications, but the adoption of these standards and specifications and their application in e-Learning practice. Approaches concerning LOM Standard Application Profiles (APs) and curricula mapping are the main topics created and investigated here because they could provide more quick and convenient LOs search possibilities in the repositories for the users. Another key factor is quality of DLE systems, and therefore one more research object of the work is the effectiveness of methods of DLE components evaluation. DLE components’ complex evaluation tools suitable for systems based on flexible approach have been created. These tools should include a number of criteria to evaluate LOs reusability level and VLEs adaptation capabilities. Practice of flexible DLE software creation and development for Lithuanian primary, secondary and vocational education based of flexible approach is presented in more... [to full text]

Aquesta tesi està constituïda per diverses activitats de recerca, entre les quals trobam principalment articles i capítols publicats. Es descriu el disseny d'una joguina robòtica que facilita la metacognició dels nens. Es detallen els nous mètodes de disseny participatiu desenvolupats per donar suport a aquest procés, com també els resultats de les experiències dins l'aula que varen validar la seva eficàcia. Aquestes experiències varen fer servir l'especificació Unit of Practice d'Apple, la qual posibilita la descripció normalitzada de de les activitats pedagògiques amb els recursos d'ensenyament tecnològics. L'enfocament de la investigació llavors se centra en les especificacions de IMS, que representen recursos i activitats pedagògiques en un format que els ordinadors poden processar. S'analitzen les eines necessàries per treballar amb aquestes especificacions. Es fa una distinció entre processos de disseny en móns tancats (dirigits a grups limitats d'usuaris) i oberts (dirigits a un grup obert o universal). Es descriuen els processos participatius de disseny en ambdós casos. Es tenen especialment en consideració les eines necessàries per treballar amb l'especificació IMS LD, i es desenvolupen models conceptuals per clarificar la tipologia de les eines i els seus usos.Es proposa la participació en les comunitats de pràctica com una metodologia per avaluar les necessitats, les eines, i l'ús de l'especificació. / This thesis is composed of a number of related research activities, which are principally represented by means of published papers. The design of a robotic toy to provide support for children's meta-cognition is described. The new participatory design methods developed to support this process are detailed, together with the results of field trials which validated its effectiveness. These trials make use of Apple's Unit of Practice specification for the consistent description of pedagogic activities with technological teaching resources. The investigation of IMS' machine readable representations of pedagogy, their use, and the tooling they require, then becomes the focus for the inquiry. A distinction is drawn between closed world design processes, addressed at a circumscribed user group, and open world design addressing a wide or universal user group. Participatory design processes in both contexts are described. A particular focus is tooling for the IMS LD specification, and conceptual models are developed to clarify its tooling and use. Engagement with communities of practice is proposed as a means of addressing open world design challenges, and this methodology is used to assess user needs, tooling and use of the specification.