Indexing data for efficient search capabilities is a core problem in many domains of computer science. As applications centered around semantic data sources become more common, the need for more sophisticated indexing and querying capabilities arises. In particular, the need to search for specific information in the presence of a terminology or ontology (i.e. a set of logic based rules that describe concepts and their relations) becomes of particular importance, as the information a user seeks may exists as an entailment of the explicit data by means of the terminology. This variant on traditional indexing and search problems forms the foundation of a range of possible technologies for semantic data. In this work, we propose an ordering language for specifying partial orders over semantic data items modeled as descriptions in a description logic. We then show how these orderings can be used as the basis of a search tree index for processing \emph{concept searches} in the presence of a terminology. We study in detail the properties of the orderings and the associated index structure, and also explore a relationship between ordering descriptions called \emph{order refinement}. A sound and complete procedure for deciding refinement is given. We also empirically evaluate a prototype implementation of our index structure, validating its potential efficacy in semantic query problems.

In this thesis, we plan to use a group-based semantic-expansion approach to design a new personalised system framework. Semantic web and group preference offer solution to the above problem. In this thesis, ontologies and semantic techniques are applied in different components of the framework. Information has been gathered from different resources and each of the resource might be using various types of identifiers for the same concept, therefore semantic web technologies are used to find out if the concept is the same or not. On the other hand, we create group preference in our personalization system. If the system fails to obtain personal preference from new user, group preference supports the system providing recommendation to the new user according to group classification.

Indexing data for efficient search capabilities is a core problem in many domains of computer science. As applications centered around semantic data sources become more common, the need for more sophisticated indexing and querying capabilities arises. In particular, the need to search for specific information in the presence of a terminology or ontology (i.e. a set of logic based rules that describe concepts and their relations) becomes of particular importance, as the information a user seeks may exists as an entailment of the explicit data by means of the terminology. This variant on traditional indexing and search problems forms the foundation of a range of possible technologies for semantic data. In this work, we propose an ordering language for specifying partial orders over semantic data items modeled as descriptions in a description logic. We then show how these orderings can be used as the basis of a search tree index for processing \emph{concept searches} in the presence of a terminology. We study in detail the properties of the orderings and the associated index structure, and also explore a relationship between ordering descriptions called \emph{order refinement}. A sound and complete procedure for deciding refinement is given. We also empirically evaluate a prototype implementation of our index structure, validating its potential efficacy in semantic query problems.

Service-oriented Architecture is now an important issue when it comes to program development. However, there is not yet an efficient and effective way for developer to obtain appropriate component. Current researches mostly focus on either textual meaning or ontology relation of the services. In this research we propose a hybrid approach that integrates both types of information. It starts by defining important attributes and their weights for web service discovery using Multiple Criteria Decision Making. Then a method of similarity calculation based on both textual and ontological information is applied. In the experiment, we collect 103 real-world Web services, and the experimental results show that our approach generally performs better than the existing ones.

Interoperability between Geographic Information System (GIS) of different infrastructure companies is still a problem to be handled. Infrastructure companies deal with many operations as a part of their daily routine such as a regular maintenance, or sometimes they deal with unexpected situations such as a malfunction due to natural event, like a flood or an earthquake. These situations may affect all companies and affected infrastructure companies response to these effects. Responses may result in consequences and in order to model these consequences on GIS, GISs are able to share information, which brings the interoperability problem into the scene. The present research, aims at finding an answer to interoperability problem between GISs of different companies by considering contextual information. During the study, the geographical features are handled as the major concern and interoperability problem is examined by targeting them. The model constructed in this research is based on the ontology and because the meaning of the terms in the ontology depends on the context, ontology based context modeling is also used. v In this research, a system implementation is done for two different GISs of two

Στις μέρες μας η χρήση των κινητών συσκευών έχει σημειώσει αλματώδη ανάπτυξη και έχει γίνει αναπόσπαστο κομμάτι της καθημερινότητάς μας. Οι κινητές συσκευές με το πλήθος διαθέσιμων εφαρμογών και δυνατοτήτων που διαθέτουν, καθώς και με τη δυνατότητα πρόσβασης στο Διαδίκτυο, τείνουν να αντικαταστήσουν τους ηλεκτρονικούς υπολογιστές καθώς και μια πληθώρα άλλων συσκευών. Στην παρούσα μεταπτυχιακή διπλωματική εργασία προτείνουμε και υλοποιούμε ένα σύστημα, το οποίο κινείται στα πλαίσια των τεχνολογιών κινητού υπολογισμού και σχεδιάστηκε για να χρησιμοποιείται από τους χρήστες προκειμένου να δέχονται προτάσεις προς επιλογή σχετικά με ταινίες. Το σύστημα αποτελείται από μία κινητή συσκευή η οποία επικοινωνεί με μια οντολογία με χρήση της τεχνολογίας των web services. Όταν ο χρήστης συνδέεται στο λογαριασμό του έχει τη δυνατότητα να πραγματοποιήσει δύο διαδικασίες οι οποίες λειτουργούν με διαφορετικό αλγόριθμο συστάσεων. Στόχος μας είναι να ελέγξουμε κατά πόσο ένα σύστημα συνεργατικών συστάσεων είναι πιο αποδοτικό από ένα σύστημα που λαμβάνει υπόψη το προσωπικό προφίλ ενός χρήστη. Στην παρούσα περίπτωση διαλέξαμε έναν συγκεκριμένο αριθμό ταινιών με παρόμοιο κριτήριο για χρονολογίες από το 2006 έως το 2014. Εφαρμόσαμε τον αλγόριθμο συνεργατικής σύστασης για ταινίες από το 2006 έως το 2010 και τον αλγόριθμο που βασίζεται στο προφίλ μόνο του συνδεδεμένου χρήστη για ταινίες από το 2011 έως το 2014 λαμβάνοντας μια αξιολόγηση για το καθένα. / Nowadays, the use of mobile devices has rapidly developed and has become an integral part of our daily lives. Mobile devices have now a great number of applications and features available, along with the internet accessibility, they tend to replace not only computers but also a variety of other devices. In this master thesis, we propose and implement a system that runs in the context of mobile computing technologies and is designed to be used in order to present to the user all the recommended for him movies. This program consists of a mobile device that communicates with an ontology through a web service. When the user signs in to his account, has the ability to hold two processes each one operating with a different recommendation engine. Our intention is to check whether a collaborative recommendation engine is more efficient than a system which takes into account only the personal profile of a user. In this case study we chose a certain number of films based on a standard for a period of time, from 2006 to 2014. We applied the collaborative recommendation engine to movies from 2006 to 2010 and the algorithm based on the profile of the user signed–into movies released from 2011 to 2014 taking an assessment for each.

Η αξιοποίηση του Διαδικτύου και των σχετικών τεχνολογιών από τη σύγχρονη βιομηχανική επιχείρηση αναμένεται να δημιουργήσει σημαντική προστιθέμενη αξία τόσο όσον αφορά στην εσωτερική επιχειρησιακή οργάνωση όσο και στην εφαρμογή νέων προηγμένων μοντέλων διεπιχειρησιακής ολοκλήρωσης. Έτσι καθίσταται δυνατή η διάφανη και διαλειτουργική ολοκλήρωση συστημάτων / εφαρμογών εντός της βιομηχανικής επιχείρησης που συντελεί στη σύνδεση της παραγγελίας όπως τίθεται από τον πελάτη με αυτή καθ’ εαυτή την παραγωγική διαδικασία. Κατ’ αυτόν τον τρόπο είναι εφικτό το πέρασμα από τη σημερινή κατάσταση της μαζικής παραγωγής προϊόντων στην κατάσταση της εξατομικευμένης παραγωγής επί παραγγελία. Ουσιαστικά λοιπόν η ολοκλήρωση του «πελάτη» (ατόμου ή επιχείρησης) στην όλη παραγωγική διαδικασία είναι το επόμενο βήμα πρωτοβουλιών που έχουν ήδη γνωρίσει σημαντική ανάπτυξη και οι οποίες θα μπορούσαν να ομαδοποιηθούν ως ηλεκτρονική επιχειρηματικότητα. Επιπρόσθετα, η σύγχρονη λειτουργία των επιχειρήσεων στη διεθνοποιημένη οικονομία, επιβάλλει αυξημένα επίπεδα συνεργασίας μεταξύ των επιχειρήσεων, ώστε να αξιοποιούνται τα σημεία στα οποία η κάθε μία έχει ανταγωνιστικά πλεονεκτήματα, με αποτέλεσμα οικονομίες κλίμακος και αυξημένη ανταγωνιστικότητα. Σε αυτό το πλαίσιο εντάσσονται σύγχρονες μορφές διεπιχειρησιακής οργάνωσης και λειτουργίας όπως ομαδοποιήσεις επιχειρήσεων (clusters), εικονικές (virtual) επιχειρήσεις, εκτεταμένες (extended) επιχειρήσεις, βάσει προηγμένων επιχειρησιακών μοντέλων όπως για παράδειγμα του μοντέλου συνεργατικού επιχειρείν ή συνεργατικού κατασκευάζειν. Οι ανωτέρω αναφερόμενες μορφές οργάνωσης αποτελούν μονόδρομο για μικρές σχετικά χώρες όπως η Ελλάδα, προκειμένου να υποβοηθηθούν οι Μικρές και Μεσαίες Επιχειρήσεις τους να ενταχθούν στο διεθνές γίγνεσθαι. Η εφαρμογή των ανωτέρω προηγμένων μοντέλων δεν θα ήταν εφικτή χωρίς την υποστήριξη τεχνολογιών επιχειρησιακής και διεπιχειρησιακής ολοκλήρωσης, τεχνολογιών σημασιολογικής αναπαράστασης καθώς και χωρίς το σημερινό βαθμό διείσδυσης των πληροφοριακών και επικοινωνιακών τεχνολογιών. Κλειδί για την εφαρμογή της ιδέας του συνεργατικού κατασκευάζειν είναι η διαλειτουργική ολοκλήρωση σε πραγματικό χρόνο, όπως αυτός ορίζεται στην συγκεκριμένη περίπτωση, των συστημάτων / εφαρμογών όλων των σχετικών επιπέδων της βιομηχανικής επιχείρησης η οποία αποσκοπεί στην άμβλυνση των ιεραρχικών βιομηχανικών δομών και στην ανάδειξη μιας σημασιολογικά επισημειωμένης προηγμένης βιομηχανικής δομής για την αρραγή εκτέλεση των χαρακτηριστικών για την περίπτωση αυτή επιχειρησιακών διαδικασιών. Έτσι λοιπόν, στην κατεύθυνση αυτή έρχεται να συμβάλλει η εργασία που παρουσιάζεται στα πλαίσια της παρούσας διδακτορικής διατριβής αντικείμενο της οποίας αποτέλεσε η μελέτη του προβλήματος διαλειτουργικής ολοκλήρωσης δηλ. της σημασιολογικής ενοποίησης συστημάτων / εφαρμογών της βιομηχανικής επιχείρησης υπό το πρίσμα των απαιτήσεων που τίθενται από το συνεργατικό κατασκευάζειν και η υλοποίηση πρωτότυπης καινοτομικής μεθοδολογίας εκτέλεσης των χαρακτηριστικών συνεργατικών διαδικασιών. / -

The last three decades has seen the successful development of many high-throughput technologies that have revolutionised and transformed biological research. The application of these technologies has generated large quantities of data allowing new approaches to analyze and integrate these data, which now constitute the field of Systems Biology. Systems Biology aims to enable a holistic understanding of a biological system by mapping interactions between all the biochemical components within the system. This requires integration of interdisciplinary data and knowledge to comprehensively explore the various biological processes of a system. Ontologies in biology (bio-ontologies) and the Semantic Web are playing an increasingly important role in the integration of data and knowledge by offering an explicit, unambiguous and rich representation mechanism. This increased influence led to the proposal of the Semantic Systems Biology paradigm to complement the techniques currently used in Systems Biology. Semantic Systems Biology provides a semantic description of the knowledge about the biological systems on the whole facilitating data integration, knowledge management, reasoning and querying. However, this approach is still a typical product of technology push, offering potential users access to the new technology. This doctoral thesis presents the work performed to bring Semantic Systems Biology closer to biological domain experts. The work covers a variety of aspects of Semantic Systems Biology: The Gene eXpression Knowledge Base is a resource that captures knowledge on gene expression. The knowledge base exploits the power of seamless data integration offered by the semantic web technologies to build large networks of varied datasets, capable of answering complex biological questions. The knowledge base is the result of the active collaboration with the Gastrin Systems Biology group here at the Norwegian University of Science and Technology. This resource was customised by the integration of additional data sets on users’ request. Additionally, the utility of the knowledge base is demonstrated by the conversion of biological questions into computable queries. The joint analysis of the query results has helped in filling knowledge gaps in the biological system of study. Biologists often use different bioinformatics tools to conduct complex biological analysis. However, using these tools frequently poses a steep learning curve for the life science researchers. Therefore, the thesis describes ONTO-ToolKit, a plug-in that allows biologists to exploit bio-ontology based analysis as part of biological workflows in Galaxy. ONTO-ToolKit allows users to perform ontology-based analysis to improve the depth of their overall analysis Visualisation plays a key role in aiding users understand and grasp the knowledge represented in bio-ontologies. To this end, OLSVis, a web application was developed to make ontology browsing intuitive and flexible. Finally, the steps needed to further advance the Semantic Systems Biology approach has been discussed. / Semantic Systems Biology

The idea of this work is to propose a method of Web data aggregation employing ontology. This method is required as a part of major method proposed by Vytautas Taujanskas and Rimantas Butleris in paper “Categories extraction for reuse in semantic applications and profile based recommendation service” [1]. The main task of the method aims to semantic portal users who request to get information according their profile settings based and described with meaningful semantics. The requirements of method are created based on requirements of Semantic Web implementation and Semantic Web Services concepts. The vision of Semantic Web, Web Ontology Language, Resource Description Framework, Semantic Query Language for RDF, Ontology tools and frameworks issues are discussed. Also the main techniques of current Web for data syndication, aggregation and publishing in various feeds formats (Atom, RSS) among users are introduced. The proposed method integrates available techniques and creates possibility of aggregated data storing in ontology based databases. The data represented by ontology can be re-used by another system without loosing semantics and more flexible. The project model of method implementation was created and implemented by using JAVA programming language combining available techniques described in analysis phase. The experiment with test data and use case tests shows that method can be implemented successfully with available tools as a part of Semantic Web application.

In this thesis the Semantic Web and its core technology---Web Ontology Language (OWL)---were studied. Considering the features of the different units involved in the dairy industry, OWL, in its capacity as an ontology description language, can be used to encode and thus exchange ontology among the units in the dairy industry. After creation of OWL file using Protege, an OWL parser was programmed to decode the ontology and data contained in the OWL file. Based on these investigations, it was determined that OWL can be used to encode, exchange, and decode data between farms and the units that interact with them, although large volumes of data among the service agencies pose certain challenges in terms of transfer size. A structure of the Semantic Web services in the dairy industry is proposed for Semantic Web Service registration, search and usage related to certain farm-management tasks. With the help of the Semantic Web and OWL, one can expect a more efficient data processing in the future dairy industry.