@article {827, title = {An Assessment of the Effectiveness of the Remedial Teaching Education Policy}, journal = {Knowledge}, volume = {3}, year = {2023}, month = {jul}, pages = {349{\textendash}363}, abstract = {

The remedial teaching policy is a flagship education policy of the Greek Ministry of Education that aims to create a school of equal opportunities by providing additional support to students from disadvantaged social backgrounds. In this work we utilised a data set provided by the Ministry of Education, followed a black box approach and built on previous results in order to achieve the first ever evaluation, based on data, of the remedial teaching policy. Our findings indicate that remedial teaching is very effective in supporting very weak students, helping 70\% of them achieve better academic performance and one out of three of them to sustain this enhanced academic performance in the future, long after they have stopped receiving remedial teaching. On the other hand, and contrary to what is widely believed, our results show that remedial teaching has the opposite impact to what it was designed for, as it is primarily the privileged students that receive the benefits. Consequently, in the way it is currently implemented, remedial teaching widens the gap between privileged and disadvantaged students rather than reduces it. The implications of the work are wide and far reaching, including the establishment of the need to revisit the way remedial teaching is implemented, the highlighting of the value in the data gathered by the Ministry of Education and the proof that individual educational policies can be objectively assessed despite being part of a complex system in which multiple education policies are implemented concurrently.

}, keywords = {black box evaluation, data driven evaluation, education policy, remedial teaching}, doi = {https://doi.org/10.3390/knowledge3030024}, url = {https://doi.org/10.3390/knowledge3030024}, author = {Ilias Papadogiannis and Manolis Wallace and Vassilis Poulopoulos and Costas Vassilakis and Georgios Lepouras and Nikos Platis} } @article {831, title = {Blockchain meets Internet of Things (IoT) forensics: A unified framework for IoT ecosystems}, journal = {Internet of Things}, year = {2023}, month = {oct}, pages = {100968}, abstract = {

With the continuously increasing number of security incidents targeting sensors, embedded devices, and other electronics appliances and systems that comprise the so-called Internet of things (IoT), the field of IoT forensics emerged as a branch of digital forensics focusing on the investigation of attacks in the IoT ecosystem. Digital evidence authenticity, integrity, confidentiality, and privacy are among the factors affecting the investigation process in IoT forensics, which can be addressed by employing the blockchain as the means not only for the preservation of digital evidence, but also for other steps of a digital forensics investigation process. The high-level goal of the paper is three-fold: to establish a holistic IoT forensics process as a reference point against which blockchain integration patterns and best practices will be identified in order to yield a robust, widely accepted and scalable architecture of the blockchain-enabled solution; to integrate the blockchain with the proposed IoT forensics process for addressing the above challenges; and to evaluate the overall solution highlighting improvements and potential performance bottlenecks. The proposed blockchain-enabled platform leverages multi-access edge computing and has been implemented with Hyperledger Fabric on an extensive virtualized testbed providing a realistic smart home environment. A thorough evaluation was conducted with real cyber-attacks generating digital evidence at high rates for testing the platform{\textquoteright}s behavior at high load. The experimental results showed that the proposed platform achieved high throughput, excessively low latency, and zero error rate in the operation of the blockchain network.

}, keywords = {blockchain, cyber-security, Digital forensics, Edge computing, Internet of Things}, doi = {10.1016/j.iot.2023.100968}, url = {https://www.sciencedirect.com/science/article/pii/S2542660523002913}, author = {Sotirios Brotsis and Konstantinos P. Grammatikakis and Dimitrios Kavallieros and Antonio I. Mazilu and Nicholas Kolokotronis and Konstantinos Limniotis and Costas Vassilakis} } @article {828, title = {Chatbots for Cultural Venues: A Topic-Based Approach}, journal = {Algorithms}, volume = {16}, year = {2023}, month = {jul}, pages = {339}, abstract = {

Digital assistants{\textemdash}such as chatbots{\textemdash}facilitate the interaction between persons and machines and are increasingly used in web pages of enterprises and organizations. This paper presents a methodology for the creation of chatbots that offer access to museum information. The paper introduces an information model that is offered through the chatbot, which subsequently maps the museum{\textquoteright}s modeled information to structures of DialogFlow, Google{\textquoteright}s chatbot engine. Means for automating the chatbot generation process are also presented. The evaluation of the methodology is illustrated through the application of a real case, wherein we developed a chatbot for the Archaeological Museum of Tripolis, Greece.

}, keywords = {chatbots, cultural venues, Museums, RDF triples, topics}, doi = {10.3390/a16070339}, url = {https://doi.org/10.3390/a16070339}, author = {Vasilis Bouras and Dimitris Spiliotopoulos and Dionisis Margaris and Costas Vassilakis and Konstantinos Kotis and Angeliki Antoniou and George Lepouras and Manolis Wallace and Vassilis Poulopoulos} } @conference {801, title = {An Interface for User-Centred Process and Correlation Between Large Datasets}, booktitle = {Proceedings of the 2021 International Conference on Human-Computer Interaction: Design, User Experience, and Usability: UX Research and Design}, year = {2021}, publisher = {Springer International Publishing}, organization = {Springer International Publishing}, address = {Cham}, abstract = {

Standard database query systems are designed to process data on a single installation only, and do not provide optimal solutions for cases that data from multiple sources need to be queried. In these cases, the sources may have different data schemata, data representations etc., necessitating extensive coding and data transformations to retrieve partial results and combine them to reach the desired outcome. Differences in schemata and representations may be subtle and remain unnoticed, leading to the production of erroneous results. The goal of this paper is to present an easy-to-use solution for the end users, enabling them to query data from a given set of databases through a single user interface. This user interface allows users to visualize database contents and query results, while facilities for uploading and validating the data are also accommodated. To demonstrate the applicability of our approach, a use case is presented where data from two different sources are uploaded into the system and thereafter the data from the two databases can be utilized in tandem. The usability evaluation involved software developers in free evaluation scenarios.

}, keywords = {big data, Multiple data sources, Query, Usability, user interface, Visualisation}, isbn = {978-3-030-78221-4}, doi = {https://doi.org/10.1007/978-3-030-78221-4_32}, author = {Spiliotopoulos, Dimitris and Giannakopoulos, Theodoros and Costas Vassilakis and Wallace, Manolis and Lantzouni, Marina and Poulopoulos, Vassilis and Dionisis Margaris} } @conference {lykourentzou_2019_crops, title = {Exploring Self-organisation in Crowd Teams}, booktitle = {Proceedings of the Crowd-Powered e-Services (CROPS) Workshop in the context of the 19th IFIP Conference on e-Business, e-Services and e-Society (I3E 2019)}, year = {2020}, month = {01/2020}, abstract = {

Online crowds have the potential to do more complex work in teams, rather than as individuals. Team formation algorithms typically maximize some notion of global utility of team output by allocating people to teams or tasks. However, decisions made by these algorithms do not consider the decisions or preferences of the people themselves. This paper explores a complementary strategy, which relies on the crowd itself to self-organize into eective teams. Our preliminary results show that users perceive the ability to choose their teammate extremely useful in a crowdsourcing setting. We also nd that self-organisation makes users feel more productive, creative and responsible for their work product.

}, keywords = {computer-supported collaboration, creative writing, crowd teams, self-organization}, doi = {10.1007/978-3-030-39634-3_15}, author = {Ioanna Lykourentzou and Antonios Liapis and Costas Papastathis and Konstantinos Papangelis and Costas Vassilakis} } @article {770, title = {A Semantic Mixed Reality Framework for Shared Cultural Experiences Ecosystems}, journal = {Big Data and Cognitive Computing}, volume = {4}, year = {2020}, month = {4/2020}, pages = {6}, abstract = {This paper presents SemMR, a semantic framework for modelling interactions between human and non-human entities and managing reusable and optimized cultural experiences, towards a shared cultural experience ecosystem that might seamlessly accommodate mixed reality experiences. The SemMR framework synthesizes and integrates interaction data into semantically rich reusable structures and facilitates the interaction between different types of entities in a symbiotic way, within a large, virtual, and fully experiential open world, promoting experience sharing at the user level, as well as data/application interoperability and low-effort implementation at the software engineering level. The proposed semantic framework introduces methods for low-effort implementation and the deployment of open and reusable cultural content, applications, and tools, around the concept of cultural experience as a semantic trajectory or simply, experience as a trajectory (eX-trajectory). The methods facilitate the collection and analysis of data regarding the behaviour of users and their interaction with other users and the environment, towards optimizing eX-trajectories via reconfiguration. The SemMR framework supports the synthesis, enhancement, and recommendation of highly complex reconfigurable eX-trajectories, while using semantically integrated disparate and heterogeneous related data. Overall, this work aims to semantically manage interactions and experiences through the eX-trajectory concept, towards delivering enriched cultural experiences.}, keywords = {cultural experience, intelligent interaction, Mixed Reality, semantics, Usability}, doi = {https://doi.org/10.3390/bdcc4020006}, author = {Costas Vassilakis and Konstantinos Kotis and Dimitris Spiliotopoulos and Dionisis Margaris and Vlasios Kasapakis and Christos-Nikolaos Anagnostopoulos and Georgios Santipantakis and George A. Vouros and Theodore Kotsilieris and Volha Petukhova and Andrei Malchanau and Ioanna Lykourentzou and Kaj Michael Helin and Artem Revenko and Nenad Gligoric and Boris Pokric} } @article {787, title = {Visualizing the educational data mining literature}, journal = {European Journal of Engineering Research and Science}, volume = {TBD}, year = {2020}, month = {TBD}, abstract = {

This article provides a visualization of a literature review in students{\textquoteright} performance prediction using educational data mining (EDM) techniques for the period 2015-2019. The results of the review are presented concisely and simply with the use of diagrams. Various aspects of the literature are examined, such as the algorithms adopted, the type of results drawn, the educational setting of the application and the actual exploitation of the outcomes. Findings indicate that tertiary education dominates the EDM field; in contrast, the focus given to secondary and primary education is minimal.

}, keywords = {Educational Data Mining, Literature review, Student Performance, Visualization}, author = {I. Papadogiannis and N. Platis and V. Poulopoulos and Costas Vassilakis and G. Lepouras and M. Wallace and G. Karountzou} } @conference {Theodoropoulos_2019_atmf, title = {ATMF: A student-centered framework for the effective implementation of alternative teaching methods for CSEd}, booktitle = {Proceedings of the Innovative Teaching of Introductory Topics in Information Technology - 3(IT) Workshop in the context of the 19th IFIP Conference on e-Business, e-Services and e-Society (I3E 2019)}, year = {2019}, month = {01/2020}, abstract = {

The dynamic development of Informatics introduces new educational and pedagogical challenges, including the instructional design of teaching and learning. How can we teach our students better in such a growing and demanding field? Moreover, how can we motivate them and together have better learning results? This paper aims to give answers to these questions, through a student-centered framework for effectively encompassing alternative teaching methods within CS. The proposed framework (ATMF) summarizes the benefits of alternative teaching methods in contrast with known is-sues of traditional teaching. In addition, ATMF is built upon empirical evidence and concludes that alternative practices, if used under the right conditions, can provide increased motivation for learning and better learning out-comes.

}, keywords = {Alternative Teaching Methods, Computer Science Education, Teaching Framework}, doi = {10.1007/978-3-030-39634-3_11}, author = {Anastasios Theodoropoulos and Costas Vassilakis and Angela Antoniou and Manolis Wallace and Giorgos Lepouras} } @article {715, title = {Bringing a peripheral, traditional venue to the digital era with targeted narratives}, journal = {Digital Applications in Archaeology and Cultural Heritage}, volume = {14}, year = {2019}, month = {sep}, pages = {e00111}, abstract = {The current work presents a method of enhancing museum content with narratives targeting history reflection in a personalized manner, delivered by an especially designed mobile app. The mobile app is a part of a technology ecosystem that supports the visitor before, during and after her visit. Within the framework of the European H2020 CrossCult project, a method was designed, implemented and tested to enhance museum content with digital material, enriched narratives and means to actively engage visitors. In particular, the method was implemented and tested for the content of the Archaeological Museum of Tripolis (Greece) and specific content examples are presented here, together with data from visitor evaluation. The results showed that content was significantly and qualitatively enhanced and visitors recognized the potential of the app in triggering visitor curiosity, new forms of engagement, and the ability to reflect on the connections between historical and social phenomena.}, keywords = {Cultural heritage, Museum app, Narratives, reflection, Visitor experience}, doi = {10.1016/j.daach.2019.e00111}, url = {https://www.sciencedirect.com/science/article/pii/S2212054819300098}, author = {Angeliki Antoniou and Susana Reboreda Morillo and George Lepouras and Jason Diakoumakos and Costas Vassilakis and Martin Lopez Nores and Catherine Emma Jones} } @conference {Antoniou_2019_Mytilene, title = {Cultural technologies: the case of the Tripolis archeological museum (in Greek; Greek title: "ΠΟΛΙΤΙΣΤΙΚΕΣ ΤΕΧΝΟΛΟΓΙΕΣ: Η ΠΕΡΙΠΤΩΣΗ ΤΟΥ ΑΡΧΑΙΟΛΟΓΙΚΟΥ ΜΟΥΣΕΙΟΥ ΤΡΙΠΟΛΗΣ")}, booktitle = {Book of abstracts of the 2nd Conference of the School of Social Sciences of the University of the Aegean "Social sciences today: dilemmas and prospectives beyond the crisis"}, year = {2019}, abstract = {The Tripolis archeological museum hosts magnificent ancient art exhibits from the whole of the Arcadia county. However, a series of issues, including the old-style museological exhibition and the limited informational material offered to the visitor, combined with the lack of digital presence for the museum, lead to a low number of visitors. Culural technologies may offer solutions to these issues that the museum fronts, and to this end the museum was included in the CrossCult EU project (www.crosscult.eu). In the context of the project, the antecendents regarding the technological design for the particular museum were studied (staff, visitor and technological equipment needs), and the characteristics of the museum collections were examined. With the collaboration of the Ephorate of Antiquities of Arcadia, the most important and characteristic exhibits were identified, among those that were linked to the position of the woman in the ancient society. Using these exhibits as a basis, 7 thematic itineraries were created in both the English and the Greek language, which support the user in visiting the museum halls and exhibitions and learning certain aspects of women{\textquoteright}s lives in the antiquity (e.g. education, everyday life, social status, etc). Each exhibit is linked with different digital cultural artefacts (e.g. images from other collections, related videos, games, sound clips etc.), to create narratives that increase user engagement and stimulate reflection. In parallel, a series of games was deveped, aiming to disseminate the presence of the museum and the information sourced from it through the social networks, assist in creating user profiles and further promote the museum. Finally, user experience can continue after the visit, through the use of a specialized social network, created specifically for the needs of the museum. (Abstract in Greek follows: Το αρχαιολογικό μουσείο Τρίπολης στεγάζει καταπληκτικά δείγματα αρχαίας τέχνης από ολόκληρο τον νομό Αρκαδίας. Όμως μια σειρά προβλημάτων, όπως η παλαιού τύπου μουσειολογική έκθεση και το πολύ συνοπτικό πληροφοριακό υλικό που προσφέρεται στον επισκέπτη, μαζί με το γεγονός ότι το μουσείο δεν έχει ψηφιακή παρουσία, οδηγεί σε χαμηλή επισκεψιμότητα. Οι πολιτιστικές τεχνολογίες μπορούν να προσφέρουν λύσεις στα προβλήματα του μουσείου και έτσι το μουσείο εντάχθηκε στο Ευρωπαϊκό ερευνητικό έργο CrossCult (www.crosscult.eu). Μέσα στα πλαίσια του έργου, μελετήθηκαν τα προαπαιτούμενα σχεδιασμού τεχνολογιών για το συγκεκριμένο χώρο (ανάγκες προσωπικού, ανάγκες επισκεπτών, ανάγκες τεχνολογικού εξοπλισμού), καθώς και τα χαρακτηριστικά των συλλογών. Με τη βοήθεια της Εφορείας Αρχαιοτήτων Αρκαδίας, εντοπίστηκαν τα σημαντικότερα και χαρακτηριστικότερα εκθέματα, γύρω από το θέμα της θέσης της γυναίκας στον αρχαίο κόσμο. Με βάσει τα εκθέματα αυτά, δημιουργήθηκαν 7 θεματικές διαδρομές (σε Ελληνικά και Αγγλικά) όπου ο επισκέπτης μπορεί να περιηγηθεί στο μουσείο και να μάθει για συγκεκριμένες πτυχές της ζωής των γυναικών (π.χ. εκπαίδευση, καθημερινότητα, κοινωνική θέση, κλπ). Το κάθε έκθεμα συνδέεται με διαφορετικά ψηφιακά πολιτιστικά αντικείμενα (π.χ. εικόνες από εκθέματα άλλων συλλογών, σχετικά βίντεο, παιχνίδια, αρχεία ήχου, κλπ) για να δημιουργηθούν αφηγήσεις που να αυξάνουν τον προβληματισμό και την εμπλοκή του επισκέπτη. Παράλληλα, μια σειρά παιχνιδιών υλοποιήθηκε με σκοπό τη διάχυση στα μέσα κοινωνικής δικτύωσης για τη δημιουργία προφίλ επισκεπτών και την περαιτέρω διαφήμιση του μουσείου. Τέλος, η εμπειρία μπορεί να συνεχιστεί και μετά την επίσκεψη με τη χρήση εξειδικευμένου κοινωνικού δικτύου, φτιαγμένου ειδικά για τους επισκέπτες του μουσείου.)}, url = {https://www.propobos.gr/?id=3247\&\&atfc=3250}, author = {Angela Antoniou and Giorgos Lepouras and Costas Vassilakis and Manolis Wallace and Nikos Platis} } @conference {725, title = {Kalamata 1821: Roads of Freedom - Digital applications teach history (Greek title: Καλαμάτα 1821: Δρόμοι Ελευθερίας {\textendash} Οι ψηφιακές εφαρμογές διδάσκουν ιστορία)}, booktitle = {2nd Panhellenic conference on Open Educational Resources and e-learning}, year = {2019}, abstract = {The {\textquotedblleft}Kalamata 1821: Roads of Freedom{\textquotedblright} project is an effort for scientifically organizing the celebration of the 200-year anniversary from the liberation of Greece from the Turkish thrall, with a special focus on the city of Kalamata. The project, aiming to link historical memories to the modern era, includes a major section related to the development of digital applications. The project{\textquoteright}s digital applications are developed by the Knowledge and Uncertainty lab of the Department of Informatics and Telecommunications of the University of the Peloponnese. The digital applications are based on the information provided by the historical scientific team of the project. Within the project, two distinct groups of applications are developed, in order to cover the diverse needs of the target population. The nature of the applications is clearly didactic, offering detailed information regarding historical facts, places and persons which relate to the Greek War of Independence, as well as on locations where important events took place. The Interactive Table applications are a group of applications which will be available to the public visiting the historic building of the old Town Hall of Kalamata, where the project exhibition center is located. These applications constitute a modern, interactive, digital encyclopedia of the relation between the city of Kalamata and the Greek War of Independence. For the Interactive Table, three original applications were developed. The first depicts histories and facts linked to some points on a map. The second presents a tree of histories, that is histories that are interrelated, and where each visitor may familiarize with facts and persons that are linked to each other. Finally, the third application focuses on images and multimedia, challenging the visitors to identify and elaborate on events and histories hiding behind pictures. The second group consists of a single application that targets on a wider public that prefers a different type on interaction. Effectively this application implements a scavenger hunt with historic content. The goal of this application is to motivate the visitor of the city of Kalamata to wander around the city, and also to link the project to the local market.}, keywords = {Educational applications, Interactive table, Mobile applications}, author = {M. Wallace and V. Poulopoulos and A. Antoniou and Costas Vassilakis and G. Lepouras and J. Diakoumakos and V. Panagiotidou} } @conference {714, title = {PaloAnalytics project concept, scope and outcomes: an opportunity for culture}, booktitle = {Proceedings of the Workshop on Cultural Informatics, co-located with the 14th International Workshop On Semantic And Social Media Adaptation And Personalization (SMAP 2019)}, year = {2019}, abstract = {This paper describes the national funded project entitled PaloAnalytics, which develops an innovative platform that allows companies and organizations, that operate in several countries, to monitor and analyze, in depth, the markets{\textquoteright} interest to their products and successfully plan their marketing and communication strategy, with data and insights collected from all the local media, and focuses on its application to cultural spaces and museums. In this notion, we examine the effect that this project can have in cultural spaces or companies related to arts and culture. PaloAnalytics platform allows organizations to investigate the impact of their products on consumers across different countries and this is achieved with the analysis of content from sites, blogs, social networks and open data. This implies that cultural organization can benefit by adopting the implemented services, so that the can recognize and analyze their audience, their online marketing campaigns as well as examine the impact of their messages and the spread of their messages on the Internet. In this paper, we briefly describe the project and discuss on the impact on cultural related organizations.}, keywords = {big data, data monitoring, Data visualization, deep learning, influencers, infographics, trending topics}, url = {http://ceur-ws.org/Vol-2412/paper7.pdf}, author = {Vassilis Poulopoulos and Manolis Wallace and Costas Vassilakis and George Lepouras}, editor = {Angeliki Antoniou and Manolis Wallace} } @conference {726, title = {Scavenger Hunt in the Roads of Freedom (Greek title: {\textquotedblleft}Κυνήγι θησαυρού στους Δρόμους της Ελευθερίας")}, booktitle = {Proceedings of the 3nd Pan-Hellenic Conference on Digital Cultural Heritage-EuroMed 2019}, year = {2019}, abstract = {The project "Kalamata 1821: Roads of freedom" is being funded in the context of the Action "RESEARCH - CREATE - INNOVATE. The project, which encompasses original historic research work in the University of the Peloponnese, is an effort to narrate a historic course of 200 years for the city of Kalamata, from the eruption of the Greek revolution until today, through a modern and fresh perspective. This paper will present one of the digital applications developed within the project, and more specifically the Scavenger Hunt that is being developed by the Knowledge and Uncertainty lab of the Department of Informatics and Telecommunications in Tripolis. The game is designed for mobile devices and its goal is to link the historic content of the project with the contemporary city and, in a gamified fashion, assist the user not only to familiarize with the history of the city but also to navigate in the city and connect with the local market. By searching through pictures of various locations of the city, the visitor is directed to the most outstanding locations of the war of independence, and learns about the contribution of the city of Kalamata in this turning point for the history of the Greek nation. At the same time, the visitor is rewarded by receiving offers for local stores.}, keywords = {Greek War of Independence, Kalamata, Roads of Freedom, Scavenger Hunt}, author = {Manolis Wallace and Vassilis Poulopoulos and George Lepouras and Costas Vassilakis and Angeliki Antoniou} } @conference {727, title = {Supporting small museums through social network semantic analysis (Greek title: Υποστήριξη μικρών μουσείων μέσω της σημασιολογικής ανάλυσης κοινωνικών δικτύων)}, booktitle = {Proceedings of the 3nd Pan-Hellenic Conference on Digital Cultural Heritage-EuroMed 2019}, year = {2019}, abstract = {Greece has a significant historic, archaeological and cultural wealth, and a big number of museums and related venues. Some of them are big, both in size and resources -human as well as financial. Most venues however are small in size, are not connected with larger organizations, have constrained budgets and little or no permanent staff. In this paper, we focus on that particular category of museums. Many of these museums possess noteworthy collections, and it would be desirable if the general public could enjoy them. Unfortunately, in most cases, even the existence of the museums is not generally known, even to inhabitants of the cities at which the museums are located. The small number of visitors leads to confined revenues, and this in turn leads to a situation which is not financially viable. In order for a small museum to survive, its existence and value must be made known to the wide public. However, this is inhibited due to the lack of resources to finance advertising and the lack of specialized personnel. In this paper, we combine our experiences on small museums, which has been developed within the CrossCult H2020 project, with know-how on social network analysis which has been gained in the context of the PaloAnalytics national project, in order to offer viable solutions for promotion, which are tailored to the needs of small museums.}, keywords = {semantic analysis, small-sized museums, Social Networks}, author = {Manolis Wallace and Vassilis Poulopoulos and George Lepouras and Costas Vassilakis and Angeliki Antoniou} } @conference {724, title = {TripMentor: Challenges and prospects for culture and tourism in the Attica region (Greek title: {\textquotedblleft}TripMentor: προκλήσεις και προοπτικές για τον πολιτισμό και τον τουρισμό στην περιφέρεια Αττικής{\textquotedblleft})}, booktitle = {Proceedings of the 3nd Pan-Hellenic Conference on Digital Cultural Heritage-EuroMed 2019}, year = {2019}, abstract = {This paper presents the TripMentor project which is related to the tourism and civilization in the region of Attica. The main goal of the project is the presentation, in two languages, of the rich cultural content of the region to the tourists, through an Internet-based environment and through mobile applications. The goal of the project is to guide the visitors through many possible alternative routes, which include points of interest, as well as enterprises with tourism-related offers, while at the same time attempts to combine these routes with cultural points of interest. The project interrelates information, venues and visitor profiles with an automated way, striving to offer a unique personalized experience, tailored to the needs and preferences of each user. The project challenges are mainly technical, since through the project procedures (a) information regarding the points of interest should be gathered in an automated fashion (b) information about events related to points of interest must be taken into account and (v) data related to users, and especially the user profiles must be discovered and exploited so that the available information can be synthesized into a unique experience. In this context, we present the project application domain and the related challenges.}, keywords = {cultural information, culture, geospatial data, Social Networks, tourism, visitor profile}, author = {Costas Vassilakis and Vassilis Poulopoulos and Manolis Wallace and Angeliki Antoniou and George Lepouras} } @conference {713, title = {TripMentor Project: scope and challenges}, booktitle = {Proceedings of the Workshop on Cultural Informatics, co-located with the 14th International Workshop On Semantic And Social Media Adaptation And Personalization (SMAP 2019)}, year = {2019}, abstract = {We present Tripmentor, a novel project, that is related to tourism in the region of Attica. The project has as main scope to provide rich media content to tourists through a web and mobile environment in two languages trying to guide them through alternative routes that include places of interest as well as organizations with offers to tourists. The project interconnects people with places and events in an automated manner trying to personalize on each tourist{\textquoteright}s personality. The challenges of the project are mainly technological as through the processes of the project a) automated information about venues must be collected, b) information about events related to venues must be fetched and finally c) data related to system users and mainly their profile should be discovered and created in order to offer a unique experience to each of them. We present the scope of the project as well as the challenges of its implementation.}, keywords = {cultural related information, geodata, personalization, social media, tourism, tripmentor}, url = {http://ceur-ws.org/Vol-2412/paper6.pdf}, author = {Costas Vassilakis and Vassilis Poulopoulos and Manolis Wallace and Angeliki Antoniou and George Lepouras}, editor = {Angeliki Antoniou and Manolis Wallace} } @inbook {Vasilakis2018BigData, title = {Big Data Platforms and Applications}, year = {2018}, publisher = {Springer}, organization = {Springer}, chapter = {exhiSTORY: Smart self-organizing exhibits}, abstract = {Creating stories for exhibitions is a fascinating and in parallel laborious task. As every exhibition is designed to tell a story, museum curators are responsible for identifying, for each exhibit, its aspects that fit to the message of the story and position the exhibit at the right place in the story thread. In this context we analyze how the technological advances in the fields of sensors and Internet of Things can be utilized in order to construct a "smart space", which consists of self-organizing exhibits that cooperate with each other and provide visitors with comprehensible, rich, diverse, personalized and highly stimulating experiences. We present the system named "exhiSTORY" that intends to provide the appropriate infrastructure to be used in museums and places where exhibitions are held in order to support smart exhibits. The architecture of the system and its application potential is presented and discussed.}, author = {Costas Vassilakis and Vassilis Poulopoulos and Angela Antoniou and Manolis Wallace and Giorgos Lepouras and Martin Lopez Nores}, editor = {TBC} } @conference {poulopoulos2018a, title = {The Effect of Social Media Trending Topics Related to Cultural Venues{\textquoteright} Content}, booktitle = {2018 13th International Workshop on Semantic and Social Media Adaptation and Personalization (SMAP)}, year = {2018}, month = {sep}, publisher = {IEEE}, organization = {IEEE}, abstract = {Social media have gained the majority of attention on the Internet having an extreme number of daily visitors worldwide. The amount of information exchanged is vast, while users have become equally producers and consumers of data. Words like {\textquotedblleft}trending{\textquotedblright}, {\textquotedblleft}influencers{\textquotedblright}, {\textquotedblleft}likes{\textquotedblright} and {\textquotedblleft}viral{\textquotedblright} are in the daily agenda of data analyzers, as they are associated with factors that play an important role in the influence of social media content to its audience. These aspects are nowadays strongly taken into account by organizations that want to draw the public{\textquoteright}s attention to the content they deliver, and in this context cultural institutions have already started to take under great consideration not only their presence in social media, but also the exploitation of social media dynamics. In this paper we propose a method that can enable cultural venues to benefit from matches between their own content and ongoing discussions on social media. More specifically we extract trending topics that can be related semantically with the content of a cultural institute and examine how a venue can benefit by exploiting these matches. The proposed algorithm has been developed in the scope of the {\textquotedblleft}CrossCult{\textquotedblright} H2020 project, and has been experimentally tested by analyzing the case of Twitter in Greek language.}, keywords = {cultural informatics, cultural venues, personalization, social media, trending topics}, doi = {10.1109/SMAP.2018.8501878}, author = {Vassilis Poulopoulos and Costas Vassilakis and Manolis Wallace and Angela Antoniou and Giorgos Lepouras} } @book {DBLP:reference/db/2018, title = {Encyclopedia of Database Systems, Second Edition}, year = {2018}, publisher = {Springer}, organization = {Springer}, isbn = {978-1-4614-8266-6}, doi = {10.1007/978-1-4614-8265-9}, url = {https://doi.org/10.1007/978-1-4614-8265-9}, editor = {Ling Liu and M. Tamer {\"O}zsu} } @conference {PoulopoulosGIIS2018, title = {ExhiSTORY: IoT in the service of Cultural Heritage}, booktitle = {Proceedings of the Global Information Infrastructure and Networking Symposium (GIIS 2018), Special Session on IoT and Cultural Heritage Protection}, year = {2018}, month = {oct}, publisher = {IEEE}, organization = {IEEE}, abstract = {Creating stories for exhibitions is a fascinating and in parallel laborious task. As every exhibition is designed to tell a story, museum curators are responsible for analyzing each exhibit in order to extract messages that form a story and position accordingly the objects in correct order within the museum space. In this context, we analyze how the technological advances in the fields of sensors and the Internet of Things can be utilized in order to construct a {\textquotedblleft}smart space{\textquotedblright}, where exhibits can communicate with the visitors and to each other and can be organized automatically so that they can generate rich, personalized, coherent and highly stimulating experiences. We present the architecture of the system named {\textquotedblleft}exhiSTORY{\textquotedblright}, that intends to provide the appropriate infrastructure to be used in museums and places where exhibitions are held, in order to support smart exhibits. We discuss and analyze the architecture of the system and the ways of its application in a cultural space.}, doi = {10.1109/GIIS.2018.8635759}, author = {Vassilis Poulopoulos and Costas Vassilakis and Angela Antoniou and Manolis Wallace and Giorgos Lepouras and Martin Lopez Nores} } @article {Vassilakis_fgcs17, title = {exhiSTORY: Smart Exhibits That Tell Their Own Stories}, journal = {Future Generation of Computer Systems}, volume = {81}, year = {2018}, pages = {542-556}, abstract = {Museum exhibitions are designed to tell a story; this story is woven by curators and in its context a particular aspect of each exhibit, fitting to the message that the story is intended to convey, is highlighted. Adding new exhibits to the story requires curators to identify for each exhibit its aspects that fit to the message of the story and position the exhibit at the right place in the story thread. The availability of rich semantic information for exhibits, allows for exploiting the wealth of meanings that museum exhibits express, enabling the automated or semi-automated generation of practically countless stories that can be told. Personalization algorithms can then be employed to choose from these stories the ones most suitable for each individual user, based on the semantics of the stories and information within the user profile. In this work we examine how opportunities arising from technological advances in the fields of IoT and semantics can be used to develop smart, self-organizing exhibits that cooperate with each other and provide visitors with comprehensible, rich, diverse, personalized and highly stimulating experiences. These notions are included in the design of a system named exhiSTORY, which also exploits previously ignored information and identifies previously unseen semantic links. We present the architecture of the system and discuss its application potential.}, keywords = {Cultural heritage, IoT, personalization, Quality of Experience (QoE), Self-organizing exhibitions, semantics}, doi = {https://doi.org/10.1016/j.future.2017.10.038}, url = {https://www.sciencedirect.com/science/article/pii/S0167739X17324093}, author = {Costas Vassilakis and Vassilis Poulopoulos and Angela Antoniou and Manolis Wallace and Giorgos Lepouras and Martin Lopez Nores} } @conference {angelantEuromed18, title = {The Human Computer Interaction and Virtual Reality Lab (University of Peloponnese): overview and current challenges}, booktitle = {Proceedings of the {\textquotedblleft}Cultural informatics research and applications: State of the art and open challenges{\textquotedblright} workshop, within the Euromed 2018 Conference}, year = {2018}, month = {oct}, abstract = {The Human-Computer Interaction and Virtual Reality Lab, at the Department of Informatics and Telecommunications of the University of Peloponnese, aims to conduct high quality research in areas related to the analysis, design, develop-ment, and evaluation of HCI and VR systems and applications, and in parallel to support the teaching requirements of the department in the respective field. Over the last years the HCI-VR lab particularly focuses on Cultural Heritage and de-velops technologies primarily for spaces of cultural heritage that cover the diverse needs of heterogeneous audiences providing holistic visitor experience. The HCI-VR lab is actively participating in National and European projects on Cultural Heritage, such as FP7 Experimedia (https://hci-vr.dit.uop.gr/experimedia), H2020 CrossCult (www.crosscult.eu) and multiple projects from the National Strategic Reference Framework.}, url = {http://ceur-ws.org/Vol-2235/paper10.pdf}, author = {Angela Antoniou and Costas Vassilakis and Anastasios Theodoropoulos and Giorgos Lepouras} } @conference {vacilosEuromed18, title = {Personality Analysis of Social Media Influencers as a Tool for Cultural Institutions}, booktitle = {Digital Heritage. Progress in Cultural Heritage: Documentation, Preservation, and Protection}, year = {2018}, pages = {236{\textendash}247}, publisher = {Springer International Publishing}, organization = {Springer International Publishing}, abstract = {Nowadays, more and more cultural venues tend to utilize social media as a main tool for marketing, spreading their messages, engaging public and raising public awareness towards culture. It comes to a point where the massive of content in social media makes it a tedious procedure to contact the appropriate audience, the people that would really be stimulated by cultural information. In this notion, we assume that establishing conversations of high impact can possibly guide the cultural venues to audiences that can benefit more. These conversations usually include the so called influencers, users whose opinion can affect many people on social media; the latter usually referred to as followers. In this research paper we examine the characteristics of the influencers that can affect the procedures of a cultural venue on social media. The research is done within the scope of "CrossCult" EU funded project.}, keywords = {cultural informatics, influencers, personality traits, social media, user modeling}, doi = {10.1007/978-3-030-01762-0_20}, author = {Vassilis Poulopoulos and Costas Vassilakis and Angela Antoniou and Giorgos Lepouras and Manolis Wallace} } @article {Poulopoulos2018Heritage, title = {The personality of the influencers, the characteristics of qualitative discussions and their analysis for recommendations to cultural institutions}, journal = {Heritage}, volume = {1}, number = {2}, year = {2018}, month = {oct}, pages = {239-253}, abstract = {Social media usage is affecting peoples{\textquoteright} views through opinion sharing, a fact that has started to attract cultural institutions, as it is possible that this procedure can possibly be a part of a museum experience. As the main goal of a cultural institution is the maximization of senses stimulation, the device that is offered to the visitors{\textquoteright} hands everyday and every moment, becomes an important tool for the art spaces. In this notion we perform research on issues that can be of great importance for the museum{\textquoteright}s online presence and attraction. We focus on establishing the personality of influencers related to culture, as well as the characteristics of qualitative discussions on the social media. Crosscult Project is an EU funded project, that aims to spur a change in the way European citizens appraise History, and sets that basis of our research as the experiments are conducted within its scope of. Through the experimental procedure, we collect information in order to define the character of the influencer and the substances of a {\textquotedblleft}serious{\textquotedblright} conversation. {\textquotedblleft}Serious{\textquotedblright} conversations are regarded the ones in which a cultural organization can participate actively and benefit from the participation. We present the results of our experimental evaluation and analyze how cultural institutions can benefit from the outcomes of our research.}, keywords = {cultural informatics, digital humanities, personality traits, personalization, serious conversations, social media influencers, user modeling}, issn = {2571-9408}, doi = {10.3390/heritage1020016}, url = {https://doi.org/10.3390/heritage1020016}, author = {Vassilis Poulopoulos and Costas Vassilakis and Angela Antoniou and Giorgos Lepouras and Anastasios Theodoropoulos and Manolis Wallace} } @article {DBLP:journals/jbi/PoulisLSG17, title = {Anonymizing datasets with demographics and diagnosis codes in the presence of utility constraints}, journal = {Journal of Biomedical Informatics}, volume = {65}, year = {2017}, pages = {76{\textendash}96}, doi = {10.1016/j.jbi.2016.11.001}, url = {https://doi.org/10.1016/j.jbi.2016.11.001}, author = {Giorgos Poulis and Grigorios Loukides and Spiros Skiadopoulos and Aris Gkoulalas-Divanis} } @conference {antoniouEuromed2017, title = {Experiences from the development of thematic itineraries in three Greek museums (Greek title: Εμπειρίες από την ανάπτυξη θεματικών διαδρομών σε τρία Ελληνικά μουσεία)}, booktitle = {Proceedings of the 2nd PanHellenic conference on Cultural Heritage (Euromed 2017)}, year = {2017}, month = {12}, abstract = {Private museums, as well as a considerable number of public regional museums, are confined by the small exhibition space and the relatively small number of exhibits and therefore cannot develop multiple exhibitions to satisfy visitors with different interests and characteristics. In this paper we report on our experieces from developing multiple thematic itineraries in the Tegea Folklore Museum , in the Cretan open-air museum "Lychnostatis" in Heraclion, and in the Panarcadic Archaeological Museum of Tripolis. The thematic itineraries in the Tegea Folklore Museum are (a) space (b) technology and (c) clothing. In the Cretan open-air museum "Lychnostatis", the itineraries are (a) natural sciences,(b) popular art, (c) pre-industrial technology and (d) folklore. In the Panarcadic Archaeological Museum of Tripolis we have the following itineraries: (a) appearance/clothing, (b) mortality, (c) nudity, (d) religion, (e) social status, (f) education, (g) healing practices and (h) everyday life. Each itinerary exploits a subset of the available exhibits to present a selected subject and is adapted to the needs of a predetermined and focused group of the general public. The results from the application of the approach, insofar, have shown that this is a promising path, both regarding the better exploitation of the space and the exhibits of the small museums, as well as regarding the better adaptation to the interests of the visitors.}, author = {Angela Antoniou and Costas Vassilakis and Manolis Wallace and Giorgos Lepouras and Vassilis Poulopoulos} } @conference {bourlakos-ikc17, title = {Formalization and visualization of the narrative for museum guides}, booktitle = {Proceedings of the third International KEYSTONE Conference (IKC2017)}, year = {2017}, month = {09}, publisher = {Springer}, organization = {Springer}, abstract = {There is a wide range of meta-data standards for the documentation of museum related information, such as CIDOC-CRM; these standards focus on the description of distinct exhibits. In contrast, there is a lack of standards for the digitization and documentation of the routes followed and information provided by museum guides. In this work we propose the notion of the narrative, which can be used to model a guided museum visit. We provide a formalization for the narrative so that it can be digitally encoded, and thus preserved, shared, re-used, further developed and exploited, and also propose an intuitive visualization approach.}, doi = {https://doi.org/10.1007/978-3-319-74497-1_1}, url = {https://link.springer.com/chapter/10.1007/978-3-319-74497-1_1}, author = {Ioannis Bourlakos and Manolis Wallace and Angela Antoniou and Costas Vassilakis and Giorgos Lepouras and Anna Vassiliki Karapanagiotou} } @conference {theodorakopoulos-smap2017, title = {Personalized Augmented Reality Experiences in Museums using Google Cardboards}, booktitle = {2017 12th International Workshop on Semantic and Social Media Adaptation and Personalization (SMAP)}, year = {2017}, month = {07}, publisher = {IEEE CPS}, organization = {IEEE CPS}, abstract = {In this short paper we examine the suitability of the Google Cardboard as a means for the delivery of personalized cultural experiences. Specifically, we develop the content and create the application required in order to provide highly personalized visits to the Archaeological Museum in Tripolis, Greece. We also examine the usability issues related to the use of Google Cardboards. Early results are promising, and based on them we also outline the next steps ahead.}, doi = {10.1109/smap.2017.8022676}, url = {https://ieeexplore.ieee.org/document/8022676/}, author = {Marinos Theodorakopoulos and Nikos Papageorgopoulos and Andriana Mourti and Angela Antoniou and Manolis Wallace and Giorgos Lepouras and Costas Vassilakis and Nikos Platis} } @article {vassilakis-snam-2017a, title = {Stimulation of reflection and discussion in museum visits through the use of social media}, journal = {Social Network Analysis and Mining}, volume = {7}, number = {40}, year = {2017}, month = {12}, pages = {1-12}, publisher = {Springer-Verlag GmbH Austria}, abstract = {In this paper, we examine how social media can be linked to cultural heritage and in particular how we can incorporate games, social networks, history reflection and culture. More specifically, we explore the following aspects: (a) how social media sites can be integrated into the museum user experience (b) how user interactions within the social media, both within the context of the museum experience and outside it, can be exploited to enhance the quality of recommendations made to the users, (c) how trending topics from social media can be used to link museum exhibits with today{\textquoteright}s topics of interest and (d) how multi-level related terms extraction from social media data can lead to proposals for reflections to users. The end goal is to provide increased stimuli for users to study exhibits deeper and reflect on them, as well as to trigger discussion between the users, thus maximizing the impact of a museum visit.}, keywords = {big data, cognitive style, Communication, reflection, Social Networks, user profiling}, doi = {10.1007/s13278-017-0460-3}, url = {https://link.springer.com/article/10.1007/s13278-017-0460-3}, author = {Costas Vassilakis and Angela Antoniou and Giorgos Lepouras and Vassilis Poulopoulos and Manolis Wallace and Stavroula Bampatzia and Ioannis Bourlakos} } @conference {vas-euromed16, title = {Interconnecting Objects, Visitors, Sites and (Hi)Stories Across Cultural and Historical Concepts: The CrossCult Project}, booktitle = {Digital Heritage. Progress in Cultural Heritage: Documentation, Preservation, and Protection}, year = {2016}, month = {10}, pages = {501{\textendash}510}, publisher = {Springer International Publishing}, organization = {Springer International Publishing}, abstract = {Human History, is a huge mesh of interrelated facts and concepts, spanning beyond borders, encompassing global aspects and finally constituting a shared, global experience. This is especially the case regarding European history, which is highly interconnected by nature; however, most History-related experiences that are today offered to the greater public, from schools to museums, are siloed. The CrossCult project aims to provide the means for offering citizens and cultural venue visitors a more holistic view of history, in the light of cross-border interconnections among pieces of cultural heritage, other citizens viewpoints and physical venues. To this end, the CrossCult project will built a comprehensive knowledge base encompassing information and semantic relationships across cultural information elements, and will provide the technological means for delivering the contents of this knowledge base to citizens and venue visitors in a highly personalized manner, creating narratives for the interactive experiences that maximise situational curiosity and serendipitous learning. The CrossCult platform will also exploit the cognitive/emotional profiles of the participants as well as temporal, spatial and miscellaneous features of context, including holidays and anniversaries, social media trending topics and so forth.}, doi = {10.1007/978-3-319-48496-9_39}, url = {http://link.springer.com/chapter/10.1007/978-3-319-48496-9_39}, author = {Costas Vassilakis and Angela Antoniou and Giorgos Lepouras and Manolis Wallace and Ioanna Lykourentzou and Y. Naudet} } @proceedings {DBLP:conf/esws/2016, title = {The Semantic Web. Latest Advances and New Domains - 13th International Conference, ESWC 2016, Heraklion, Crete, Greece, May 29 - June 2, 2016, Proceedings}, volume = {9678}, year = {2016}, publisher = {Springer}, isbn = {978-3-319-34128-6}, doi = {10.1007/978-3-319-34129-3}, url = {https://doi.org/10.1007/978-3-319-34129-3}, editor = {Harald Sack and Eva Blomqvist and Mathieu d{\textquoteright}Aquin and Chiara Ghidini and Simone Paolo Ponzetto and Christoph Lange} } @conference {bampatzia-gala2016, title = {Serious games: Valuable Tools for Cultural Heritage}, booktitle = {Proceedings of the 2016 Games and Learning Alliance Conference}, year = {2016}, month = {12}, pages = {331{\textendash}341}, abstract = {Wishing to connect cultural heritage, games and social networks, the present work describes games to be used within the framework of a European H2020 project. For the purposes of supporting the museum visit, before, during and after, 5 games were designed for social networks to accomplish user profil-ing, to promote the museum and the application through social network dissemi-nation, to introduce museum items and themes and to also function as visit sou-venirs. The games are also presented in a generic framework for games in cultural heritage, which has been used successfully in the past.}, doi = {https://doi.org/10.1007/978-3-319-50182-6_30}, url = {https://link.springer.com/chapter/10.1007/978-3-319-50182-6_30}, author = {Stavroula Bampatzia and Ioannis Bourlakos and Angela Antoniou and Costas Vassilakis and Giorgos Lepouras and Manolis Wallace} } @conference {bampatzia2016a, title = {The use of semantics in the CrossCult H2020 project}, booktitle = {Proceedings of the second International KEYSTONE Conference, (IKC2016)}, year = {2016}, pages = {190{\textendash}195}, abstract = {CrossCult is a newly started project that aims to make reflective history a reality in the European cultural context. In this paper we examine how the project aims to take advantage of advances in semantic technologies in order to achieve its goals. Specifically, we see what the quest for reflection is and, through practical examples from two of the project{\textquoteright}s flagship pilots, explain how semantics can assist in this direction}, doi = {https://doi.org/10.1007/978-3-319-53640-8_17}, url = {https://link.springer.com/chapter/10.1007/978-3-319-53640-8_17}, author = {Stavroula Bampatzia and Omar Gustavo Bravo-Quezada and Angela Antoniou and Martin Lopez Nores and Manolis Wallace and Giorgos Lepouras and Costas Vassilakis} } @conference {bampatzia-smap16, title = {Using Social media to stimulate history reflection in cultural heritage}, booktitle = {Proceedings of Semantic and Social Media Adaptation and Personalization (SMAP) 2016}, year = {2016}, month = {10}, abstract = {CrossCult H2020 is a European project, the aim of which is the reflection of history in a cultural setting. In this paper, we describe how social media can be linked to cultural heritage and in particular how we can incorporate games, social networks, history reflection and culture. The paper presents the case study of one of the project pilots, to show how history reflection can be enhanced with the use of social networks.}, doi = {10.1109/SMAP.2016.7753390}, url = {https://ieeexplore.ieee.org/document/7753390/}, author = {Stavroula Bampatzia and Angela Antoniou and Giorgos Lepouras and Costas Vassilakis and Manolis Wallace} } @article {katifori15a, title = {Effectiveness of visualization for information retrieval through ontologies with entity evolution: the impact of ontology modeling}, journal = {International Journal of Information Retrieval Research}, volume = {5}, number = {2}, year = {2015}, pages = {26}, abstract = {Incorporating digital tools in the business and scientific research workflows is at the moment an on-going process, challenging and demanding as every domain has its own needs in terms of data models and information retrieval methods. The information in some domains involves entity evolution, a characteristic that introduces additional tasks, such as finding all evolution stages of an entity, and poses additional requirements for the information retrieval process. In this paper, we present a user study aiming to investigate how the different aspects of ontology modelling affect the performance and effectiveness of users regarding information retrieval tasks that are carried out using visualization methods. The results of the user study are analyzed and guidelines for ontology design are offered.}, doi = {10.4018/IJIRR.2015040104}, author = {Akrivi Katifori and Costas Vassilakis and Giorgos Lepouras and Elena Torou} } @book {DBLP:books/sp/GL2015, title = {Medical Data Privacy Handbook}, year = {2015}, publisher = {Springer}, organization = {Springer}, isbn = {978-3-319-23632-2}, doi = {10.1007/978-3-319-23633-9}, url = {https://doi.org/10.1007/978-3-319-23633-9}, editor = {Aris Gkoulalas-Divanis and Grigorios Loukides} } @conference {kmas15, title = {A mobile-enabled platform for presenting and disseminating cultural heritage information enhanced with augmented reality (Greek title: ΜΙΑ ΠΛΑΤΦΟΡΜΑ ΓΙΑ ΠΑΡΟΥΣΙΑΣΗ ΚΑΙ ΔΙΑΧΥΣΗ ΠΛΗΡΟΦΟΡΙΩΝ ΠΟΛΙΤΙΣΤΙΚΗΣ ΚΛΗΡΟΝΟΜΙΑΣ ΜΕ ΥΠΟΣΤΗΡΙΞΗ ΓΙΑ ΚΙΝΗΤΕΣ ΣΥΣΚΕΥΕΣ ΚΑΙ ΕΜΠ}, booktitle = {1st Panhellenic Conference on Cultural Heritage Digitization}, year = {2015}, month = {9}, abstract = {The advent of mobile technologies has created opportunities for more effective delivery of cultural heritage information to all interested parties, and especially tourists who are on-the-move. Many people nowadays are equipped with smartphones or tablets equipped with location tracking devices such as GPS and compasses and having internet access available; these smartphones can be used for efficient delivery of cultural heritage information, in a personalized and timely fashion. Moreover, the computing resources of these smartphones are adequate to enable the use of augmented reality techniques, which provide a lively and engaging experience to the users. However, the same content still needs to be disseminated to users of stationary computers. In this paper, we report on the design and development of a mobile-enabled platform for presenting and disseminating cultural heritage information enhanced with augmented reality and integration with social networks.}, author = {K. Μασσέλος and Costas Vassilakis and Giorgos Lepouras and Christos Tryfonopoulos and Ν. Τσελίκας and Nikos Platis} } @conference {556, title = {A Platform for the Presentation and Dissemination of Cultural Heritage Information for Mobile Devices Enriched with Augmented Reality}, booktitle = {Proceedings of the Greek Conference for the Digitization of Cultural Information (EUROMED)}, year = {2015}, month = {September}, address = {Volos, Greece}, author = {K. Masselos and Costas Vassilakis and Giorgos Lepouras and Christos Tryfonopoulos and N. Tselikas and N. Platis} } @inbook {565, title = {SECRETA: A Tool for Anonymizing Relational, Transaction and RT-Datasets}, booktitle = {Medical Data Privacy Handbook}, year = {2015}, pages = {83-109}, publisher = {Springer}, organization = {Springer}, author = {Giorgos Poulis and Aris Gkoulalas-Divanis and Grigorios Loukides and Spiros Skiadopoulos and Christos Tryfonopoulos}, editor = {Aris Gkoulalas-Divanis and Grigorios Loukides} } @inbook {DBLP:books/sp/15/PoulisGLST15, title = {SECRETA: A Tool for Anonymizing Relational, Transaction and RT-Datasets}, booktitle = {Medical Data Privacy Handbook}, year = {2015}, pages = {83{\textendash}109}, doi = {10.1007/978-3-319-23633-9_5}, url = {https://doi.org/10.1007/978-3-319-23633-9_5}, author = {Giorgos Poulis and Aris Gkoulalas-Divanis and Grigorios Loukides and Spiros Skiadopoulos and Christos Tryfonopoulos} } @article {DBLP:journals/tdp/PoulisSLG14, title = {Apriori-based algorithms for k\(^\mboxm\)-anonymizing trajectory data}, journal = {Trans. Data Privacy}, volume = {7}, number = {2}, year = {2014}, pages = {165{\textendash}194}, url = {http://www.tdp.cat/issues11/abs.a194a14.php}, author = {Giorgos Poulis and Spiros Skiadopoulos and Grigorios Loukides and Aris Gkoulalas-Divanis} } @conference {Rompa2014, title = {Mindmap-Inspired Semantic Personal Information Management}, booktitle = {Demo at the 17th International Conference on Extending Database Technology, 2014, Athens, Greece}, year = {2014}, month = {3/2014}, abstract = {Users nowadays need to manage large amounts of information, including documents, e-mails, contacts, and multimedia content. To facilitate the tasks of organisation, maintenance, and retrieval of personal information, a number of semantics-based methods have emerged; these methods employ (personal) ontologies as an underlying infrastructure for organising and querying the personal information space. In this paper we present OntoFM, a novel personal information management tool that offers a mindmap-inspired interface to facilitate user interactions with the information base. Besides serving as an information retrieval aid, OntoFM allows the user to specify and update the semantic links between information items, constituting thus a complete personal information management tool.}, doi = {10.5441/002/edbt.2014.55}, url = {http://dx.doi.org/10.5441/002/edbt.2014.55}, author = {Rompa, J. and Christos Tryfonopoulos and Costas Vassilakis and Giorgos Lepouras} } @conference {553, title = {Mindmap-Inspired Semantic Personal Information Management}, booktitle = {Proceedings of the 17th International Conference on Extending Database Technology (EDBT)}, year = {2014}, month = {March}, address = {Athens, Greece}, author = {Jenny Rompa and Christos Tryfonopoulos and Costas Vassilakis and Giorgos Lepouras} } @proceedings {DBLP:conf/edbt/2014, title = {Proceedings of the 17th International Conference on Extending Database Technology, EDBT 2014, Athens, Greece, March 24-28, 2014}, year = {2014}, publisher = {OpenProceedings.org}, url = {http://openproceedings.org/html/pages/2014_edbt.html}, editor = {Sihem Amer-Yahia and Vassilis Christophides and Anastasios Kementsietsidis and Minos N. Garofalakis and Stratos Idreos and Vincent Leroy} } @conference {DBLP:conf/edbt/PoulisGLST14, title = {SECRETA: A System for Evaluating and Comparing RElational and Transaction Anonymization algorithms}, booktitle = {Proceedings of the 17th International Conference on Extending Database Technology, EDBT 2014, Athens, Greece}, year = {2014}, month = {March 24-28}, pages = {620{\textendash}623}, doi = {10.5441/002/edbt.2014.58}, url = {https://doi.org/10.5441/002/edbt.2014.58}, author = {Giorgos Poulis and Aris Gkoulalas-Divanis and Grigorios Loukides and Spiros Skiadopoulos and Christos Tryfonopoulos} } @conference {lep14a, title = {Towards a Learning Analytics Platform for Supporting the Educational Process}, booktitle = {Proceedings of the 5th Conference on Information, Intelligence, Systems \& Application (IISA2014)}, year = {2014}, month = {7}, abstract = {In this paper, we present the vision of an open source learning analytics platform, able to harvest data from different sources, including e-learning platforms and environments, registrar{\textquoteright}s information systems, alumni systems, etc., so as to provide all stakeholders with the necessary functionality to make decisions on the learning process. The platform{\textquoteright}s architecture is modular, allowing the introduction of new functionality or connection to new systems to collect needed data. All data can be analyzed and presented though interactive visualizations to find correlations between metrics, to make predictions for students or student groups, to identify best practices for instructors and let them explore {\textquoteright}what-if{\textquoteright} scenarios, to offer students personalized recommendations and personalized detailed feedback, etc. Our objective is to inform and empower all stakeholders to improve the learning experience.}, doi = {10.1109/IISA.2014.6878750}, url = {http://ieeexplore.ieee.org/document/6878750/}, author = {Giorgos Lepouras and Akrivi Katifori and Costas Vassilakis and Angela Antoniou and Nikos Platis} } @conference {Katif2014a, title = {Visualization method effectiveness in ontology-based information retrieval tasks involving entity evolution}, booktitle = {Proceedings of SMAP 2014}, year = {2014}, month = {11}, abstract = {Incorporating digital tools in the business and scientific research workflows is at the moment an on-going process, challenging and demanding as every domain has its own needs in terms of data models and information retrieval methods. The information in some domains involves entity evolution, a characteristic that introduces additional tasks, such as finding all evolution stages of an entity, and poses additional requirements for the information retrieval process. In this paper we present a user study aiming to investigate the effectiveness of current ontology browsing and visualization methods for supporting users in tasks involving research on entity evolution.}, doi = {10.1109/SMAP.2014.24}, author = {Akrivi Katifori and Costas Vassilakis and Giorgos Lepouras and C. Halatsis} } @conference {DBLP:conf/pkdd/PoulisLGS13, title = {Anonymizing Data with Relational and Transaction Attributes}, booktitle = {Machine Learning and Knowledge Discovery in Databases - European Conference, ECML PKDD 2013, Prague, Czech Republic, September 23-27, 2013, Proceedings, Part III}, year = {2013}, pages = {353{\textendash}369}, doi = {10.1007/978-3-642-40994-3_23}, url = {https://doi.org/10.1007/978-3-642-40994-3_23}, author = {Giorgos Poulis and Grigorios Loukides and Aris Gkoulalas-Divanis and Spiros Skiadopoulos} } @conference {DBLP:conf/mdm/PoulisSLG13, title = {Distance-Based k\^m-Anonymization of Trajectory Data}, booktitle = {2013 IEEE 14th International Conference on Mobile Data Management, Milan, Italy, June 3-6, 2013 - Volume 2}, year = {2013}, pages = {57{\textendash}62}, doi = {10.1109/MDM.2013.66}, url = {https://doi.org/10.1109/MDM.2013.66}, author = {Giorgos Poulis and Spiros Skiadopoulos and Grigorios Loukides and Aris Gkoulalas-Divanis} } @conference {masie2013, title = {Improving museum visitors{\textquoteright} Quality of Experience through intelligent recommendations: A visiting style-based approach}, booktitle = {Proceedings of MASIE 2013 Workshop, co-located with the 9th International Conference on Intelligent Environments IE{\textquoteright}13}, year = {2013}, month = {7}, address = {Athens, GR}, abstract = {This paper investigates the effect that smart routing and recommendations can have on improving the Quality of Experience of museum visitors. The novelty of our approach consists of taking into account not only user interests but also their visiting styles, as well as modeling the museum not as a sterile space but as a location where crowds meet and interact, impacting each visitor?s Quality of Experience. The investigation is done by an empirical study on data gathered by a custom-made simulator tailored for the museum user routing problem. Results are promising and future potential and directions are discussed.}, doi = {10.3233/978-1-61499-286-8-507}, author = {Ioanna Lykourentzou and Claude, X. and Y. Naudet and Tobias, E. and Angela Antoniou and Giorgos Lepouras and Costas Vassilakis} } @article {antoniou13x, title = {A methodology for the design of online exhibitions}, journal = {DESIDOC Journal of Library and Information Technology}, volume = {33}, number = {3}, year = {2013}, pages = {158{\textendash}167}, abstract = {The process of designing systems or products largely depends on a number of decisions, like {\textquotedblleft}who do I design for?{\textquotedblright}, {\textquotedblleft}what should my product do?{\textquotedblright}, {\textquotedblleft}what are the user requirements?{\textquotedblright} etc. The developing teams usually base their decisions on experience and/or heuristics and this is particularly the case, in the development of online products and especially online exhibitions. The different solutions are frequently case studies of specific museums or institutions that wish to provide online content to actual or possible visitors. In addition, the interdisciplinary nature of the endeavor, involving museology, technology but also education, poses important design problems. In the following sections, we present a generic methodology for the design of online exhibitions, using top-down processes and transferable findings across museum types that wish to assist the designers during the early decision stages. This paper provides an introduction to the field, emphasising its interdisciplinary nature and reviews related work in the area of online exhibition design. It also presents an overview of the methodology, elaborating on the individual methodology steps; in particular, the processes for determining the visitors{\textquoteright} perception of the museum (degree of museumness); the museum needs that require to be supported; the educational approach to be adopted; the relevance to life-long learning activities; the approach to adaptivity; and user involvement have been reviewed.}, author = {Angela Antoniou and Giorgos Lepouras and Costas Vassilakis} } @conference {DBLP:conf/icdm/PoulisSLG13, title = {Select-Organize-Anonymize: A Framework for Trajectory Data Anonymization}, booktitle = {13th IEEE International Conference on Data Mining Workshops, ICDM Workshops, TX, USA, December 7-10, 2013}, year = {2013}, pages = {867{\textendash}874}, doi = {10.1109/ICDMW.2013.136}, url = {https://doi.org/10.1109/ICDMW.2013.136}, author = {Giorgos Poulis and Spiros Skiadopoulos and Grigorios Loukides and Aris Gkoulalas-Divanis} } @conference {gala2013, title = {User Profiling: Towards a Facebook Game that Reveals Cognitive Style}, booktitle = {Proceedings of the GALA 2013 conference}, year = {2013}, month = {10}, pages = {349{\textendash}353}, address = {Paris, FR}, abstract = {This paper presents an innovative approach based on social-network gaming, which will extract players? cognitive styles for personalization purposes. Cognitive styles describe the way individuals think, perceive and remember information and can be exploited to personalize user interaction. Questionnaires are usually employed to identify cognitive styles, a tedious process for most users. Our approach relies on a Facebook game for discovering potential visitors? cognitive styles with an ultimate goal of enhancing the overall visitors{\textquoteright} experience in the museum. By hosting such a game on the museum?s webpage and on Facebook, the museum aims to attract new visitors, as well as to support the user profiling process.}, doi = {10.1007/978-3-319-12157-4_28}, author = {Angela Antoniou and Ioanna Lykourentzou and Rompa, J. and Tobias, E. and Giorgos Lepouras and Costas Vassilakis and Y. Naudet} } @article {DBLP:journals/corr/abs-1207-0135, title = {Privacy Preservation by Disassociation}, journal = {CoRR}, volume = {abs/1207.0135}, year = {2012}, url = {http://arxiv.org/abs/1207.0135}, author = {Manolis Terrovitis and John Liagouris and Nikos Mamoulis and Spiros Skiadopoulos} } @article {DBLP:journals/pvldb/TerrovitisLMS12, title = {Privacy Preservation by Disassociation}, journal = {PVLDB}, volume = {5}, number = {10}, year = {2012}, pages = {944{\textendash}955}, doi = {10.14778/2336664.2336668}, url = {http://vldb.org/pvldb/vol5/p944_manolisterrovitis_vldb2012.pdf}, author = {Manolis Terrovitis and John Liagouris and Nikos Mamoulis and Spiros Skiadopoulos} } @article {lyk11a, title = {Wikis in enterprise settings: a survey}, journal = {Enterprise Information Systems}, volume = {6}, number = {1}, year = {2012}, month = {feb}, pages = {1-53}, publisher = {Informa UK Limited}, abstract = {The wiki technology is increasingly being used in corporate environments to facilitate a broad range of tasks. This survey examines the use of wikis on a variety of organisational tasks that include the codification of explicit and tacit organisational knowledge and the formulation of corporate communities of practice, as well as more specific processes such as the collaborative information systems development, the interactions of the enterprise with third parties, management activities and organisational response in crisis situations. For each one of the aforementioned corporate functions, the study examines the findings of related research literature to highlight the advantages and concerns raised by the wiki usage and to identify specific solutions addressing them. Finally, based on the above findings, the study discusses various aspects of the wiki usage in the enterprise and identifies trends and future research directions on the field.}, doi = {10.1080/17517575.2011.580008}, url = {http://dx.doi.org/10.1080/17517575.2011.580008}, author = {Ioanna Lykourentzou and Foteini Dagka and Katerina Papadaki and Giorgos Lepouras and Costas Vassilakis} } @conference {560, title = {OntoFM: A Personal Ontology-based File Manager for the Desktop}, booktitle = {Proccedings of the International Semantic Web Conference (ISWC)}, year = {2011}, month = {October}, address = {Bonn, Germany}, author = {Jenny Rompa and Giorgos Lepouras and Costas Vassilakis and Christos Tryfonopoulos} } @conference {Rompa2011, title = {OntoFM: A Personal Ontology-based File Manager for the Desktop}, booktitle = {Demo at the 10th International Web Conference, 2011, Bonn, Germany}, year = {2011}, month = {10}, abstract = {OntoFM is a novel file manager that bases its interactivity on the user?s personal ontology, offering semantic browsing and searching mechanisms for locating files, a mind map inspired ontology visualization, and simple-to-use intuitive functionality that encourages less experienced users. The implementation of OntoFM is based on Protege, an extensible open source ontology editor and knowledge-base framework. The file manager is implemented as a Protege tab widget, retrieving information from your personal ontology. Ontology visualization is based upon the OntoGraf plug-in which has been extended to comply with the mind map paradigm. Currently the ontology visualization pane permits only navigational functions, while other ontology management functions have been hidden to ease the complexity of the user interface.}, url = {https://arxiv.org/abs/1307.2018}, author = {Rompa, J. and Giorgos Lepouras and Costas Vassilakis and Christos Tryfonopoulos} } @conference {Akim2011a, title = {Spreading Activation for Web Scale Reasoning: Promise and Problems}, booktitle = {WebSci 11, poster presentation}, year = {2011}, month = {6}, pages = {1-4}, abstract = {Various forms of spreading activation has been used in a number of web systems, not least in the PageRank algorithm. In our own work we have been using this as a technique for managing context over small and large ontologies, and both our own work and that in LarKC suggests that spreading activation has the potential to aid in reasoning over web-scale data sets including the growing set of linked open data resources. Of particular importance is that spreading activation can be applied locally to a dynamic selfselecting working set of an (practically) unbound linked data collection, as well as globally to the entire collection. However, this potential does not come without problems, some concerning the nature of the algorithm on any large data set, and some more to do with the particular nature of linked open data.}, author = {Nazihah Md. Akim and Alan Dix and Akrivi Katifori and Giorgos Lepouras and Nadeem Shabir and Costas Vassilakis} } @article {antoniou11, title = {Towards a methodological framework for the cognitive-behavioural evaluation of educational e-games}, journal = {International Journal of Learning Technology}, volume = {6}, number = {3}, year = {2011}, pages = {263{\textendash}287}, abstract = {The proposed methodological framework reviews and uses knowledge from the field of cognitive psychology in order to evaluate aspects of educational games. In particular, we concentrate on two components of human cognition that play a central role to learning, namely memory and motivation. After having reviewed theories in the field, we created a questionnaire in order to evaluate educational games. The questionnaire incorporates different experimental findings of cognitive psychology. Especially, we have applied Maslow{\textquoteright}s motivation theory, Behavioural findings on reinforcement, experimental findings about attention and memory. We present the results obtained from the evaluation of two games, PAC-MAN and Mega Jump. The results confirmed the user ratings of the two games, showing that there seem to be cognitive reasons for the success/failure of different games. Finally, lists of guidelines for developers and instructors are included.}, doi = {10.1504/11.43580}, author = {Angela Antoniou and Dimitris Diakakis and Giorgos Lepouras and Costas Vassilakis} } @article {dix2010b, title = {From the web of data to a world of action}, journal = {Journal of Web Semantics}, volume = {8 issue 4}, year = {2010}, pages = {394-408}, abstract = {This paper takes as its premise that the web is a place of action, not just information, and that the purpose of global data is to serve human needs. The paper presents several component technologies, which together work towards a vision where many small micro-applications can be threaded together using automated assistance to enable a unified and rich interaction. These technologies include data detector technology to enable any text to become a start point of semantic interaction; annotations for web-based services so that they can link data to potential actions; spreading activation over personal ontologies, to allow modelling of context; algorithms for automatically inferring {\textquoteleft}typing{\textquoteright} of web-form input data based on previous user inputs; and early work on inferring task structures from action traces. Some of these have already been integrated within an experimental web-based (extended) bookmarking tool, Snip!t, and a prototype desktop application On Time, and the paper discusses how the components could be more fully, yet more openly, linked in terms of both architecture and interaction. As well as contributing to the goal of an action and activity-focused web, the work also exposes a number of broader issues, theoretical, practical, social and economic, for the Semantic Web.}, doi = {10.1016/j.websem.2010.04.007}, author = {Alan Dix and Giorgos Lepouras and Akrivi Katifori and Costas Vassilakis and Tiziana Catarci and Antonella Poggi and Yannis Ioannidis and Miguel Morae and I. Daradimos and Nazihah Md.Akima and Shah Rukh Humayound and Fabio Terella} } @article {torou2010, title = {Historical research in archives: user methodology and supporting tools}, journal = {International Journal on Digital Libraries}, volume = {11(1)}, year = {2010}, pages = {25{\textendash}36}, abstract = {Historic research involves finding, using, and correlating informationwithin primary and secondary sources, in order to communicate an understanding of past events. In this process, historians employ their scientific knowledge, experience, and intuition to formulate queries (who was involved in an event, when did an event occur etc.), and subsequently try to locate the pertinent information from their sources. In this article, the authors investigate how historians formulate queries, which query terms are chosen, and how historians proceed in searching for related information in sources. The insight gained from this investigation can be subsequently used for organizing documentswithin historical source repositories and building tools that will enable historians to access the needed informationmore rapidly and fully.}, doi = {10.1007/s00799-010-0062-4}, author = {Elena Torou and Akrivi Katifori and Costas Vassilakis and Giorgos Lepouras and C. Halatsis} } @article {dix2010, title = {Spreading Activation Over Ontologies: From Personal Context To Web Scale Reasoning}, journal = {International Journal of Semantic Computing}, volume = {Special issue on Web Scale Reasoning}, year = {2010}, pages = {59{\textendash}102}, abstract = {This paper describes methods to allow spreading activation to be used on web-scale information resources. Existing work has shown that spreading activation can be used to model context over small personal ontologies, which can be used to assist in various user activities, for example, in autocompleting web forms. This previous work is extended and methods are developed by which large external repositories, including corporate information and the web, can be linked to the user?s personal ontology and thus allow automated assistance that is able to draw on the entire web of data. The basic idea is augment the personal ontology with cached data from external repositories, where the choice of what data to fetch or discard is related to the level of activation of entities already in the personal ontology or cached data. This relies on the assumption that the working set of highly active entities is relatively small; empirical results are presented, which suggest these assumptions are likely to hold. Implications of the techniques are discussed for user interaction and for the social web. In addition, warm world reasoning is proposed, applying rule-based reasoning over activate entities, potentially merging symbolic and sub-symbolic reasoning over web-scale knowledge bases.}, doi = {10.1142/S1793351X10000973}, author = {Alan Dix and Akrivi Katifori and Giorgos Lepouras and Costas Vassilakis and Nadeem Shabir} } @conference {537, title = {Anonymity and Censorship Resistance in Unstructured Overlay Networks}, booktitle = {Proceedings of the 17th International Conference on Cooperative Information Systems (CoopIS)}, year = {2009}, month = {November}, address = {Vilamoura, Portugal}, author = {Michael Backes and Marek Hamerlik and Alessandro Linari and Matteo Maffei and Christos Tryfonopoulos and Gerhard Weikum} } @conference {torou2009a, title = {Capturing the historical research methodology: an experimental approach}, booktitle = {Proceedings of International Conference of Education, Research and Innovation (ICERI 2009)}, year = {2009}, month = {11}, abstract = {This paper presents the results of a study on how historians conduct research in a historical archive, and the methodologies they use while searching. Historic research involves finding, using, interpreting and correlating information within primary and secondary sources, in order to understand past events. The collection of historical data is accomplished through methodical and comprehensive research in primary and secondary sources. An important factor in our study was to understand what kind of data and/or information historians are looking for in a library/historical archive, either printed or digitized, and which research methodologies or research models they use while they investigate a historical archive. Since this issue has not been addressed insofar, and therefore there are no methods for elucidating research methodologies or research models that historians employ / use, we formulated a questionnaire comprising of seven information retrieval tasks commonly addressed in the context of historic research. History researchers were asked to describe in detail how they would proceed in searching for the information they need for completing these tasks. Through this procedure we aimed to investigate the different ways a historian can use to tackle a specific question, examine whether there exists a common research methodology, and the historic researchers? expectations and preferences. The insight gained from this investigation can be used for educational purposes, since it could be useful in the creation / development of a methodology for conducting research on historical information. Furthermore, the findings can be exploited in the context of organizing documents within historical source repositories, so as to facilitate the retrieval of documents by historians; finally the presented findings can serve as a preliminary requirement analysis phase for building tools that will enable historians to access more rapidly and fully the information they need.}, author = {Elena Torou and Akrivi Katifori and Costas Vassilakis and Giorgos Lepouras and C. Halatsis} } @book {DBLP:reference/db/2009, title = {Encyclopedia of Database Systems}, year = {2009}, publisher = {Springer US}, organization = {Springer US}, isbn = {978-0-387-35544-3}, doi = {10.1007/978-0-387-39940-9}, url = {https://doi.org/10.1007/978-0-387-39940-9}, editor = {Ling Liu and M. Tamer {\"O}zsu} } @article {Vassilakis2009325, title = {A heuristics-based approach to reverse engineering of electronic services}, journal = {Information and Software Technology}, volume = {51}, number = {2}, year = {2009}, note = {cited By (since 1996) 1}, pages = {325-336}, abstract = {Since the beginning of the electronic era, public administrations and enterprises have been developing services, through which citizens, businesses and customers can conduct their transactions with the offering entity. Each electronic service contains a substantial amount of knowledge in the form help texts, rules of use or legislation excerpts, examples, validation checks, etc. This knowledge has been extracted from domain experts when the services were developed, especially in the phases of analysis and design, and was subsequently translated into software. In the latter format though, knowledge cannot be readily used in organizational processes, such as knowledge sharing and development of new services. In this paper, we present an approach for reverse engineering electronic services in order to create knowledge items of high levels of abstraction, which can be used in knowledge sharing environments as well as in service development platforms. The proposed approach has been implemented and configured to generate artifacts for the SmartGov service development platform. Finally, an evaluation of the proposed approach is presented to assess its efficiency regarding various aspects of the reverse engineering process. Β{\textcopyright} 2008 Elsevier B.V. All rights reserved.}, keywords = {Analysis and designs, Domain experts, e-government, electronic services, Government data processing, Help texts, In services, Knowledge engineering, Knowledge sharing, Levels of abstractions, Management, New services, Organizational knowledge, Organizational processes, Public administrations, Reengineering, Reverse engineering, Reverse engineering processes, Service developments, Validation checks}, doi = {10.1016/j.infsof.2008.04.003}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-56949100815\&partnerID=40\&md5=223ff82eddd9005b8e6f7fac1aa9c810}, author = {Costas Vassilakis and Giorgos Lepouras and Akrivi Katifori} } @conference {golem2009b, title = {Visualizing Hierarchies: Evaluating the Efficiency and Cognitive Effects of Six Visualization Techniques for Browsing and Management Tasks}, booktitle = {Information Visualization 2009, book of abstracts}, year = {2009}, month = {7}, abstract = {Hierarchical data structures are one of the most commonly used data structures in computer science, and therefore numerous methods and techniques have been proposed for their visualization. In this paper, we present our findings from a user study, in which a number of folder visualization environments were evaluated to assess (a) how efficiently a number of tasks can be performed within the different environments (b) the extent to which using a particular visualization may help the user acquire an accurate cognitive image of the hierarchy structure and its contents and (c) the overall user experience from using a particular visualization environment. The visualization environments considered are representative of major visualization paradigms (zoomable user interfaces, context+focus and space-filling), while both 2D and 3D environments have been included.}, author = {M. Golemati and Costas Vassilakis and Akrivi Katifori and Giorgos Lepouras and C. Halatsis} } @article {lep2008a1, title = {An active blackboard for service discovery, composition and execution}, journal = {International Journal of Electronic Governance}, volume = {1}, number = {3}, year = {2008}, pages = {275 - 295}, publisher = {Inderscience Publishers}, abstract = {Organisations are turning to customer-centric electronic services, oriented to servicing customers{\textquoteright} life-events. This development requires methods for automatically locating and synthesising individual services to compose complex ones that will service the customer{\textquoteright}s life-events, since manual composition, either at the customer or the organisation side, incurs functional, economic and technical problems. In this paper we present an active blackboard architecture, which automates the task of service composition based on the semantics of individual services and data dependencies between them. The blackboard incorporates registries, which facilitate service discovery and an execution engine that arranges for dynamic service composition and execution.}, keywords = {blackboard architecture, e-government, e-services, electronic governance, electronic services, ontologies, semantics, service composition}, doi = {10.1504/IJEG.2008.020450}, author = {Giorgos Lepouras and Costas Vassilakis and Anya Sotiropoulou and Dimitrios Theotokis and Akrivi Katifori} } @booklet {569, title = {Anonymous and Censorship-resistant Content-sharing in Unstructured Overlays}, year = {2008}, author = {Michael Backes and Marek Hamerlik and Alessandro Linari and Matteo Maffei and Christos Tryfonopoulos and Gerhard Weikum} } @conference {Mateevitsi2008451, title = {A game-engine based virtual museum authoring and presentation system}, booktitle = {Proceedings - 3rd International Conference on Digital Interactive Media in Entertainment and Arts, DIMEA 2008}, year = {2008}, note = {cited By (since 1996) 0}, month = {9}, pages = {451-457}, abstract = {In this paper we present a system that facilitates virtual museum development and usage. The system is based on a game engine, ensuring thus minimal cost and good performance, and includes provisions that enable museum curators design the virtual museum without any specialized knowledge. Besides visual and auditory information, museum curators may also provide metadata which provide additional information to the visitor, while they can be also exploited for searching for exhibits with certain properties. A guide is also included in the museum, to present additional information to the visitors and aid them throughout their tour. Copyright 2008 ACM.}, keywords = {Authoring environment, Game engines, Game theory, Metadata, Minimal costs, Museum guide, Presentation systems, Specialized knowledge, Virtual museum}, doi = {10.1145/1413634.1413714}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-62849090231\&partnerID=40\&md5=2ba9707b8125ec8f1cacaad99b611342}, author = {Mateevitsi, V. and Sfakianos, M. and Giorgos Lepouras and Costas Vassilakis} } @article {vas2008d, title = {An Integrated Environment for Cataloguing and Online Presentation of Museum Exhibits}, journal = {DESIDOC Journal of Library and Information Technology}, volume = {28(4)}, year = {2008}, pages = {72-78}, abstract = {The paper presents an integrated environment which enables museum personnel to catalogue and at the same time publish online museum exhibits. The system is based on international standards and is highly customisable to cater the needs of a variety of museum types. Moreover, the underlying database allows storing for the same exhibit documentations for different audiences and in multiple languages, while it is extendable to accommodate new media types, languages, exhibits and information categories. The administrative part of the environment permits the restriction of certain functions to specific personnel roles, enforcing thus a general museum security policy regarding access to and modification of information. The environment presented is currently in use at the Athens University History Museum.}, author = {Costas Vassilakis and Akrivi Katifori and I. Daradimos and Giorgos Lepouras} } @inbook {gol2009a, title = {Intelligent User Interfaces: Adaptation and Personalization Systems and Technologies}, year = {2008}, pages = {188{\textendash}204}, publisher = {IGI Publishing}, organization = {IGI Publishing}, chapter = {Context and Adaptivity-Driven Visualization Method Selection}, abstract = {Novel and intelligent visualization methods are being developed in order to accommodate user searching and browsing tasks, including new and advanced functionalities. Besides, research in the field of user modeling is progressing in order to personalize these visualization systems, according to its users{\textquoteright} individual profiles. However, employing a single visualization system, may not suit best any information seeking activity. In this paper we present a visualization environment, which is based on a visualization library, i.e. is a set of visualization methods, from which the most appropriate one is selected for presenting information to the user. This selection is performed combining information extracted from the context of the user, the system configuration and the data collection. A set of rules inputs such information and assigns a score to all candidate visualization methods. The presented environment additionally monitors user behavior and preferences to adapt the visualization method selection criteria.}, author = {M. Golemati and Costas Vassilakis and Akrivi Katifori and Giorgos Lepouras and C. Halatsis}, editor = {C. Mourlas and P. Germanakos} } @conference {Golemati2008106, title = {An interview-based user study on the use of visualizations for folder browsing}, booktitle = {Proceedings of the International Conference on Information Visualisation}, year = {2008}, note = {cited By (since 1996) 0}, month = {7}, pages = {106-112}, abstract = {Hierarchically structured data collections often need to be visualized for the purposes of digital information management and presentation. File browsing, in particular, has an inherent hierarchical structure and plays an important role in the context of Personal Information Management (PIM). A multitude of file browsers are nowadays available, offering different functionalities, while users adopt diverse practices and habits for browsing activities. In this paper, we investigate these aspects to obtain insights into their advantages and disadvantages and suggest solutions in the area of PIM, as well as in other domains employing similar visualization paradigms. The presented study focuses on the two most widespread visualizations used by file browsers, the indented list and zoomable interface paradigms, and assesses their effectiveness for various tasks and contexts, both by exploiting results on existing evaluations on hierarchy visualizations and folder hierarchy visualizations in particular, and by conducting an interviewbased user study. Β{\textcopyright} 2008 IEEE.}, keywords = {Administrative data processing, File browser visualization, Indented list visualization, Information analysis, Information management, Information science, Intermodulation, Intermodulation measurement, International conferences, Management, Management information systems, Telecommunication services, User study, Windows explorer}, doi = {10.1109/IV.2008.90}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-51749097531\&partnerID=40\&md5=66afc30e74191773d1c950ac83ba9ac7}, author = {M. Golemati and Akrivi Katifori and E.G. Giannopoulou and I. Daradimos and Costas Vassilakis and Giorgos Lepouras and C. Halatsis} } @article {Vassilakis2008, title = {Mobile and context-aware e-commerce: Issues, challenges and research directions}, journal = {Journal of Electronic Commerce in Organizations}, volume = {6}, number = {1}, year = {2008}, pages = {i-iv}, abstract = {Electronic commerce, nowadays, is trying to extend its target audience and elevate the quality of services offered to end-users. Two important directions towards meeting these goals are the embracement of mobile users, whose number grows following the advent of communication technologies, and the inclusion of context-aware features in the delivered services to improve the efficiency of the dialogues between users and systems. The context taken into account may involve characteristics regarding the human user, the geographical location and the time of access, the devices employed to access the service, the network through which the user communicates with the system, the nature of the transaction carried out and so forth. It is clear that the development and successful operation of mobile and context-aware e-commerce introduce new challenges. In order to tackle such challenges, new methodologies, tools, architectures and platforms should be made available to assist analysts, designers, developers and operators in handling the various phases of the Mobile and Context-Aware E-Commerce Services (MCACS) lifecycle.}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-56649115725\&partnerID=40\&md5=8375300b820641c0897304ece76039d9}, author = {Costas Vassilakis and Giorgos Lepouras and Spiros Skiadopoulos} } @conference {Katifori2008a1, title = {Personal Ontology Creation and Visualization for a Personal Interaction Management System}, booktitle = {Proceedings of PIM, CHI 2008}, year = {2008}, month = {4}, abstract = {Ontologies offer a flexible and expressive layer of abstraction, very useful for capturing the semantics of information repositories and facilitating their retrieval either by the user or by the system to support user tasks. This work presents an ontology-based user profiler, in the context of a Personal Interaction Management System (PIMS). The profiler, based on an ontology of the users? domain, enables them to create their personal ontology by initially choosing one of the available template ontologies as a starting point, which they subsequently populate and customize. The profiler employs a web interface which allows users to populate their personal ontology through forms, hiding ontology complexities and peculiarities. Forms are dynamically generated through ontology views, which are specified by ontology designers.}, author = {Akrivi Katifori and Costas Vassilakis and I. Daradimos and Giorgos Lepouras and Yannis Ioannidis and Alan Dix and Antonella Poggi and Tiziana Catarci} } @conference {Katifori2008133, title = {Selected results of a comparative study of four ontology visualization methods for information retrieval tasks}, booktitle = {Proceedings of the 2nd International Conference on Research Challenges in Information Science, RCIS 2008}, year = {2008}, note = {cited By (since 1996) 0}, month = {6}, pages = {133-140}, abstract = {The need for effective ontology visualization for design, management and browsing has arisen as a result of the progress in the areas of Semantic Web and Personal Information Management. There are several ontology visualizations available through existing ontology management tools, but not as many evaluations to determine their advantages and disadvantages and their suitability for various ontologies and user groups. This work presents selected results of an evaluation of four visualization methods in ProtΓ{\textcopyright}gΓ{\textcopyright}.}, keywords = {Communication, Comparative studies, Information management, Information retrieval, Information science, Information services, Information theory, Management, Management information systems, Ontology, Ontology managements, Personal Information managements, Semantic Web, Telecommunication services, User groups, User interfaces, Visualization, visualization methods}, doi = {10.1109/RCIS.2008.4632101}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-57349172797\&partnerID=40\&md5=1f36a9a0febecb929cd7904c84004143}, author = {Akrivi Katifori and Elena Torou and Costas Vassilakis and Giorgos Lepouras and C. Halatsis} } @conference {KatiforiGVLH07, title = {Creating an Ontology for the User Profile: Method and Applications}, booktitle = {RCIS}, year = {2007}, month = {4/2007}, pages = {407{\textendash}412}, abstract = {User profiling is commonly employed nowadays to enhance usability as well as to support personalization, adaptivity and other user-centric features. Insofar, application designers model user profiles mainly in an ad-hoc manner, hindering thus application interoperability at the user profile level, increasing the amount of work to be done and the possibility of errors or omissions in the profile model. This work aims at creating a user profile ontology that incorporates concepts and properties used to model the user profile. Existing literature, applications and ontologies related to the domain of user context and profiling have been taken into account in order to create a general, comprehensive and extensible user model. This ontology can be used as a reference model, in order to alleviate the aforementioned issues. The model, available for download, is exemplified through its application in two different areas, personal information management and adaptive visualization.}, author = {Akrivi Katifori and M. Golemati and Costas Vassilakis and Giorgos Lepouras and C. Halatsis} } @article {Lepouras200779, title = {Domain expert user development: The smartgov approach}, journal = {Communications of the ACM}, volume = {50}, number = {9}, year = {2007}, month = {sep}, pages = {79-83}, publisher = {Association for Computing Machinery (ACM)}, abstract = {SmartGov project funded by the European Union is a knowledge-based platform that assists pubic-sector employees with suitable expertise to generate online transaction devices by simplifying service development, maintenance, and integration with installed information technology systems. The project delivers intelligent e-forms development and maintenance environment and associated framework for e-government services. SmartGov address various problems faced by the stakeholders while implementing e-services such as limited view of domain experts, lost information, complexity of creating e-forms, and inadequate access. In a SmartGov approach, the implicit knowledge is made explicit in the form of documentation and data validation rules. The central concept of SmartGov is the transaction service element (TSE) that contain metadata and domain knowledge.}, keywords = {Data validation, Documentation, Information services, Information technology, Knowledge based platform, Knowledge based systems, Metadata, Online systems, Project management, Transaction service element (TSE)}, doi = {10.1145/1284621.1284623}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-34548411694\&partnerID=40\&md5=43df285b5a79ef731b3466106642af9f}, author = {Giorgos Lepouras and Costas Vassilakis and C. Halatsis and P. Georgiadis} } @inbook {vas2007a, title = {Encyclopedia of Digital Government}, year = {2007}, pages = {1174{\textendash}1179}, publisher = {IGI Publishing}, organization = {IGI Publishing}, chapter = {The Lifecycle Of Transactional Services}, abstract = {Transactional services are an indispensible part of e-government, since provision of services to citizens and enterprises,as well as the interaction between the government and citizens-enterprises are modelled mainly through such services. Latest quantifications, however, show that the development of such services lags behind as compared both to the expectations of citizens-enterprises and to the efforts made by governments. This can be attributed, amongst other reasons, to the "traditional" approach to electronic service development, which treats each electronic service as an isolated software project. In this paper, we propose an e-service development platform, which covers the whole lifecycle of transactional services and facilitates the analysis, development, deployment and maintenance of these services.}, doi = {10.4018/978-1-59140-789-8.ch177}, author = {Costas Vassilakis and Giorgos Lepouras}, editor = {Ari-Veikko Anttiroiko and Matti Malkia} } @inbook {lep2007a, title = {Encyclopedia of Digital Government}, year = {2007}, pages = {1413{\textendash}1417}, publisher = {IGI Publishing}, organization = {IGI Publishing}, chapter = {Reusability In Governmental Electronic Services}, abstract = {Reusability is the degree to which a software component or other work can be used in more than one programs or software systems. e-Government is a prosperous area for the application of reusability, since the services offered to citizens from the same administration, or even different administrations, have common portions that can be developed only once and reused wherever appropriate. In this paper we present the design and implementation of an electronic service development environment which offers the potential to reuse components that have already been implemented, for the realization of new services.}, doi = {10.4018/978-1-59140-789-8.ch216}, author = {Giorgos Lepouras and Costas Vassilakis}, editor = {Ari-Veikko Anttiroiko and Matti Malkia} } @conference {KatiforiVTLHD07, title = {Historical Archive Ontologies Requirements, Modeling and Visualization}, booktitle = {RCIS}, year = {2007}, month = {4}, pages = {401-406}, abstract = {Most ontology development methodologies and tools for ontology management deal with ontology snapshots, i.e. they model and manage only the most recent version of ontologies, which is inadequate for contexts where the history of the ontology is of interest, such as historical archives. This work presents a set of requirements for the modeling and visualization of a temporal ontology used as a tool for the representation of historical information. In accordance to these requirements, a visualization plug-in was designed and implemented, featuring a set of tools that enable users to efficiently examine ontology temporal characteristics such as class and instance evolution along the timeline.}, author = {Akrivi Katifori and Costas Vassilakis and Elena Torou and Giorgos Lepouras and C. Halatsis and I. Daradimos} } @article {Vassilakis2007113, title = {A knowledge-based approach for developing multi-channel e-government services}, journal = {Electronic Commerce Research and Applications}, volume = {6}, number = {1}, year = {2007}, note = {cited By (since 1996) 0}, pages = {113-124}, abstract = {Having realised the benefits resulting from delivering on-line public services in the context of electronic government, administrations strive to extend the spectrum of services offered to citizens and enterprises, as well as to engage multiple communication channels in service delivery, in order to increase the target audience and, consequently, the service effectiveness. Insofar, however, only the web channel has been sufficiently used for service delivery, whereas other channels have not been adequately exploited. One of the main reasons of this lag is the cost incurred for the development and maintenance of multiple versions of an electronic service, each version targeted to a different platform. In this paper, we present an approach and the associated tools for developing and maintaining electronic services that allows the automated production of different versions of the electronic service, each targeted to a specific platform. Β{\textcopyright} 2006 Elsevier B.V. All rights reserved.}, keywords = {Communication channels (information theory), e-government, Electronic commerce, electronic services, EServices, Government data processing, Knowledge based systems, Multi channel service delivery, Online systems, Websites}, doi = {10.1016/j.elerap.2006.07.004}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-33947371200\&partnerID=40\&md5=ebf06c2eee159fbeeab64c607e84415d}, author = {Costas Vassilakis and Giorgos Lepouras and C. Halatsis} } @article {Katifori2007, title = {Ontology visualization methods - A survey}, journal = {ACM Computing Surveys}, volume = {39}, number = {4}, year = {2007}, note = {cited By (since 1996) 21}, pages = {10:1-10:43}, abstract = {Ontologies, as sets of concepts and their interrelations in a specific domain, have proven to be a useful tool in the areas of digital libraries, the semantic web, and personalized information management. As a result, there is a growing need for effective ontology visualization for design, management and browsing. There exist several ontology visualization methods and also a number of techniques used in other contexts that could be adapted for ontology representation. The purpose of this article is to present these techniques and categorize their characteristics and features in order to assist method selection and promote future research in the area of ontology visualization. Β{\textcopyright} 2007 ACM.}, keywords = {Digital libraries, Human computer interaction, Information management, Ontology, Ontology representation, Ontology visualization, Personalized information management, Semantic Web, visualization methods}, doi = {10.1145/1287620.1287621}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-36048959880\&partnerID=40\&md5=a74cd76829bee9bb1cc21d6118e65340}, author = {Akrivi Katifori and C. Halatsis and Giorgos Lepouras and Costas Vassilakis and E.G. Giannopoulou} } @conference {Vassilakis20071564, title = {Web service execution streamlining}, booktitle = {Proceedings - ICSSSM{\textquoteright}06: 2006 International Conference on Service Systems and Service Management}, volume = {2}, year = {2007}, note = {cited By (since 1996) 0}, month = {10}, pages = {1564-1569}, abstract = {Web services are functional, independent components that can be called over the web to perform a task. Besides being used individually to deliver some well-specified functionality, web services may be used as building blocks that can be combined to implement a more complex function. In such compositions, typically some web services produce results that are used as input for web services that will be subsequently invoked. In the execution schemes currently employed, web services producing intermediate results deliver them to some "coordinating entity", which arranges the forwarding of these intermediate results to web services that require them as input. In this paper we present an execution scheme that employs direct communication between producers and consumers of intermediate results. Besides performance improvement stemming from reduction of network communication, this scheme permits consumer web services to employ simpler authenticity and integrity verification algorithms on incoming parameters. when the producer web service is considered trustworthy. Β{\textcopyright}2006 IEEE.}, keywords = {Algorithms, Function evaluation, Optimization, Parameter estimation, Streamlining, Web service execution, Web service synthesis, Web services}, doi = {10.1109/ICSSSM.2006.320769}, url = {http://ieeexplore.ieee.org/document/4114724/}, author = {Costas Vassilakis and Giorgos Lepouras and Akrivi Katifori} } @conference {1154709, title = {A Comparative Study of Four Ontology Visualization Techniques in Protege: Experiment Setup and Preliminary Results}, booktitle = {IV {\textquoteright}06: Proceedings of the conference on Information Visualization}, year = {2006}, month = {7}, pages = {417{\textendash}423}, publisher = {IEEE Computer Society}, organization = {IEEE Computer Society}, address = {Washington, DC, USA}, abstract = {The continuing need for more effective information retrieval has lead to the creation of the notions of the semantic web and personalized information management, areas of study that very often employ ontologies to represent the semantic context of a domain. Consequently, the need for effective ontology visualization for design, management and browsing has arisen. There are several ontology visualizations available through the existing ontology management tools, but not as many evaluations to determine their advantages and disadvantages and their suitability for various ontologies and user groups. This work presents the preliminary results of an evaluation of four visualization methods in Protege.}, isbn = {0-7695-2602-0}, doi = {10.1109/IV.2006.3}, author = {Akrivi Katifori and Elena Torou and C. Halatsis and Giorgos Lepouras and Costas Vassilakis} } @article {1412314, title = {Component reuse in electronic services development}, journal = {J. Comp. Methods in Sci. and Eng.}, volume = {6}, number = {5,6 Supplement 2}, year = {2006}, pages = {229{\textendash}241}, publisher = {IOS Press}, address = {Amsterdam, The Netherlands, The Netherlands}, abstract = {In the context of electronic government, e-services are a valuable instrument for offering high quality services to enterprises and individual citizens alike. While developing an e-service, it is usually possible to reuse elements that have already crafted for other e-services, such as personal detail forms or widgets for collecting social security numbers, decreasing thus both development effort and the time for deployment. A more generic framework for supporting reusability in development of e-services includes the identification of reusable objects, the creation and population of a repository containing such components, and the empowerment of developers with tools allowing for location, retrieval and adaptation of components for suiting their specific tasks. In this paper, we conduct an analysis to recognise e-service component that offer reusability opportunities and we present facilities and methods to enable e-service developers to exploit these opportunities while developing electronic services.}, issn = {1472-7978}, url = {http://content.iospress.com/articles/journal-of-computational-methods-in-sciences-and-engineering/jcm00134}, author = {Costas Vassilakis and Giorgos Lepouras} } @conference {Golemati200662, title = {A context-based adaptive visualization environment}, booktitle = {Proceedings of the International Conference on Information Visualisation}, year = {2006}, note = {cited By (since 1996) 0}, month = {7}, pages = {62-67}, abstract = {Digital libraries and historical archives are increasingly employing visualization systems to facilitate the information retrieval and knowledge extraction tasks of their users. Typically, each organization employs a single visualization system, which may not suit best the needs of certain user groups, specific tasks, or properties of document collections to be visualized. In this paper we present a context-based adaptive visualization environment, which embeds a set of visualization methods into a visualization library, from which the most appropriate one is selected for presenting information to the user. Methods are selected by examining parameters related to the user profile, system configuration and the set of data to be visualized, and employing a set of rules to assess the suitability of each method. The presented environment additionally monitors user behavior and preferences to adapt the visualization method selection criteria. Β{\textcopyright} 2006 IEEE.}, keywords = {(PL) properties, Adaptive systems, Adaptive visualization, Behavioral research, Digital libraries, document collections, Extraction, Information analysis, Information science, Information services, Information systems, Information visualization, Knowledge extraction, Libraries, Retrieval (MIR), Search engines, Selection criterion, Set of rules, Solvent extraction, Specific tasks, System configurations, User behaviors, User groups, user profiling, Visualization, visualization methods, Visualization systems}, doi = {10.1109/IV.2006.5}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-45149121827\&partnerID=40\&md5=ec45ad555b132faaf0bd2ca53e3292dc}, author = {M. Golemati and C. Halatsis and Costas Vassilakis and Akrivi Katifori and Giorgos Lepouras} } @conference {DBLP:conf/icdim/TorouKVLH06, title = {Creating an Historical Archive Ontology: Guidelines and Evaluation}, booktitle = {ICDIM}, year = {2006}, month = {12}, pages = {102-109}, abstract = {Ontologies have been proven invaluable tools both for the semantic web and for personal information management. In the context of a historical archive an ontology may provide meaningful and efficient support for search tasks as well as be used as a tool for storage and presentation of historical data. The creation however of such an ontology is complex, since the digitized archive documents are not in text format and the concepts that must be captured may vary among different time periods. This work presents a user-centric methodological approach for extracting the ontology of an historical archive focusing on the evaluation issues related to this process. The approach is exemplified through cases from its application in the University of Athens Historical Archive.}, doi = {10.1109/ICDIM.2007.369337}, author = {Elena Torou and Akrivi Katifori and Costas Vassilakis and Giorgos Lepouras and C. Halatsis} } @inbook {vas2006a, title = {Encyclopedia of E-Commerce, E-Government and Mobile Commerce}, year = {2006}, pages = {865{\textendash}870}, publisher = {Idea Group Inc.}, organization = {Idea Group Inc.}, chapter = {Ontology for e-Government public services}, abstract = {In this work, the usage of ontologies for meeting requirements related to e-service composition, e-service cataloguing, change management and administrative responsibility is examined. An ontology for e-government services is presented, covering various aspects of services, including administrative responsibility, meta-data, involved documents and legislation. Both the development and usage phase of the ontology are covered and directions for further exploitation of the potential offered by the ontological representation are given.}, doi = {10.4018/978-1-59140-799-7.ch139}, author = {Costas Vassilakis and Giorgos Lepouras}, editor = {Mehdi Khosrow-Pour} } @inbook {lep2006a, title = {Encyclopedia of E-Commerce, E-Government and Mobile Commerce}, year = {2006}, pages = {1064{\textendash}1069}, publisher = {Idea Group Inc.}, organization = {Idea Group Inc.}, chapter = {Tailorable e-government information systems}, abstract = {Real-world information, knowledge and procedures after which information systems are modeled are generally of dynamic nature and subject to changes, due to the emergence of new requirements or revisions to initial specifications. E-government information systems (eGIS) present a higher degree of volatility in their environment, since requirement changes may stem from multiple sources, including legislation changes, organizational reforms, end-user needs, interoperability and distribution concerns etc. To this end, the design and implementation of eGIS must adhere to paradigms and practices that facilitate the accommodation of changes to the eGIS as they occur in the real world. In this work, we present a role-based model for designing and implementing eGIS that can dynamically accomodate changes, providing the necessary facilities for modeling multiple aspects of the same real-world entities and delivering context-specific behaviour.}, doi = {10.4018/978-1-59140-799-7.ch171}, author = {Giorgos Lepouras and Anya Sotiropoulou and Dimitrios Theotokis and Costas Vassilakis}, editor = {Mehdi Khosrow-Pour} } @inbook {lep2006b, title = {Encyclopedia of E-Commerce, E-Government and Mobile Commerce}, year = {2006}, pages = {1{\textendash}6}, publisher = {Idea Group Inc.}, organization = {Idea Group Inc.}, chapter = {Adaptive Virtual Reality Shopping Malls}, abstract = {Firms and organizations are increasingly exploiting electronic channels to reach their customers and create new business opportunities. To this end, electronic shops have been developed, either offering products from a single firm or encompassing multiple individual electronic stores, comprising thus electronic shopping malls. Two main concerns for e-commerce are personalization and enhancement of user experience. Personalization addresses the ability to offer content tailored to the preferences of each user or user group. Preferences may be explicitly declared by the user, or derived by the system through inspecting user interaction; if the system dynamically reacts to changes of visitor behavior, it is termed as adaptive. Enhancement of user experience is another major issue in e-commerce, given that 2D-images and texts on the screen are not sufficient to provide information on products aspects such as physical dimensions, textures and manipulation feedback. Multimedia presentations can also be used as a means for .information acceleration. for promoting "really new" products. This article aims to specify a system that exploits capabilities offered by adaptation and VR technologies to offer e-shoppers personalized and enhanced experiences, while addressing challenges related to the cost, complexity and effort of building and maintaining such a system.}, doi = {10.4018/978-1-59904-955-7.ch099}, author = {Giorgos Lepouras and Costas Vassilakis}, editor = {Mehdi Khosrow-Pour} } @conference {DBLP:conf/icsoft/VassilakisLK06, title = {Reverse engineering electronic services: from e-forms to knowledge}, booktitle = {ICSOFT (1)}, year = {2006}, month = {9}, pages = {273-278}, abstract = {On their route to e-governance, public administrations have developed e-services. Each e-service encompasses a significant amount of knowledge in the form of examples, help texts, legislation excerpts, validation checks etc. This knowledge has been offered by domain experts in the phases of service analysis, design and implementation, being however bundled within the software, it cannot be readily retrieved and used in other organizational processes, including the development of new services. In this paper, we present an approach for reverse engineering e-services, in order to formulate knowledge items of a high level of abstraction, which can be made available to the employees of the organizations. Moreover, the knowledge items formulated in the reverse engineering process are stored into a knowledge-based e-service development platform, making them readily available for use in the development of other services.}, author = {Costas Vassilakis and Giorgos Lepouras and Akrivi Katifori} } @article {Magoulas200771, title = {Virtual reality in the e-Society}, journal = {Virtual Reality}, volume = {11}, number = {2-3}, year = {2006}, note = {cited By (since 1996) 1}, month = {dec}, pages = {71-73}, publisher = {Springer Nature}, abstract = {This special issue explores the extent to which virtual reality (VR) is affecting the creation of an electronic society. E-Society is a broad term used to describe a research area covering aspects of digital technologies for large user communities. Recent years have seen the emergence of various electronic services in an attempt to facilitate everyday life and improve the way common tasks are being carried out. The term e-Society covers a wide range of applications from e-government, e-democracy, and e-business to e-learning and e-health. In order for VR to contribute to the creation and advancement of e-Society, a number of issues have to be tackled. A successful VR system has to find a balance between the hardware requirements, user interaction methods, content presentation and the effort required for development and maintenance. Hardware requirements define to a large degree the extent to which an end-user can afford to execute the VR system at her home. User interaction methods have to cater for the variety of users? needs. Overall, design and implementation of a successful and engaging VR system is a rather difficult and complex task which requires increased effort in human power and resources in comparison to typical window based applications. Flexibility in development and subsequently maintenance of such a system can be achieved by adopting techniques already present in rapid application development environments, like abstraction, automatic code generation and reusability.}, doi = {10.1007/s10055-006-0064-0}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-34347395236\&partnerID=40\&md5=88157a2c66f3799e7bcfaf75eda9548a}, author = {G. D. Magoulas and Giorgos Lepouras and Costas Vassilakis} } @conference {1133365, title = {Visualizing a temporally-enhanced ontology}, booktitle = {AVI {\textquoteright}06: Proceedings of the working conference on Advanced visual interfaces}, year = {2006}, month = {5}, pages = {488{\textendash}491}, publisher = {ACM}, organization = {ACM}, address = {New York, NY, USA}, abstract = {Most ontology development methodologies and tools for ontology management deal with ontology snapshots, i.e. they model and manage only the most recent version of ontologies, which is inadequate for contexts where the history of the ontology is of interest, such as historical archives. This work presents a modeling for entity and relationship timelines in the Prot.g. tool, complemented with a visualization plug-in, which enables users to examine entity evolution along the timeline.}, isbn = {1-59593-353-0}, doi = {10.1145/1133265.1133365}, author = {Akrivi Katifori and Costas Vassilakis and Giorgos Lepouras and I. Daradimos and C. Halatsis} } @conference {Lepouras2005573, title = {An active ontology-based blackboard architecture for Web service interoperability}, booktitle = {2005 International Conference on Services Systems and Services Management, Proceedings of ICSSSM{\textquoteright}05}, volume = {1}, year = {2005}, note = {cited By (since 1996) 1}, month = {6}, pages = {573-578}, abstract = {Web services are functional, independent components that can be called over the web to perform a task. Web services are provided by organizations to enable others to perform tasks the organization offers online. However, with an ever increasing number of web services, finding the web service that performs a certain task is not always easy. Furthermore, adopting an end-user point of view what is needed is the actual result and not the service per se. It is often the case that more than one service have to be combined to produce the anticipated outcome, e.g. in the case of life-events. To this end, we propose an active, ontology-based blackboard architecture that aims at tackling the problems inherent in dynamic synthesis of composite web services and at facilitating user interaction with complex e-government transactions. Β{\textcopyright} 2005 IEEE.}, keywords = {Active blackboard architecture, Computer architecture, Electronic commerce, Interoperability, Ontology-based architecture, Web service synthesis, World Wide Web}, doi = {10.1109/ICSSSM.2005.1499537}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-33745256434\&partnerID=40\&md5=d1cd6446d2f3bc9ed098036d2f2bd384}, author = {Giorgos Lepouras and Costas Vassilakis and Anya Sotiropoulou and Dimitrios Theotokis and Akrivi Katifori} } @inbook {lepbook2005a, title = {Adaptable and Adaptive Hypermedia Systems}, year = {2005}, pages = {190{\textendash}205}, publisher = {IRM Press}, organization = {IRM Press}, chapter = {Adaptive Virtual Museums on the Web}, abstract = {This chapter presents an architecture for supporting the creation of adaptive virtual reality museums on the web. It argues whether the task of developing adaptive virtual reality museums is a complex one, presenting key challenges, and should thus be facilitated by means of a supporting architecture and relevant tools. The proposed architecture is flexible enough to cater for a variety of user needs, and modular promoting extensibility, maintainability and tailorability. Adoption of this architecture will greatly simplify the development of adaptive virtual reality museums, reducing the needed effort to exhibit digitisation and user profile specification; user profiles are further refined dynamically through the user data recorder and the user modelling engine, which provide input for the virtual environment generator.}, doi = {10.4018/978-1-59140-567-2.ch010}, author = {Giorgos Lepouras and Costas Vassilakis}, editor = {S. Y. Chen and G. D. Magoulas} } @article {Vassilakis_barriersto, title = {Barriers To Electronic Service Development}, journal = {e-Service Journal}, volume = {Fall 2005}, year = {2005}, pages = {41-63}, abstract = {E-government initiatives have been proven to deliver significant benefits, both for suppliers of electronic services (public authorities and organizations) and for the public, to whom services are addressed. However, the pace with which electronic services are made available and adopted is lower than planned or expected; governments tend to be slow in releasing new services, and citizens often prefer to conduct business with the government through paper forms and physical presence, rather than using online methods. This indicates that certain barriers exist that hinder the transition to electronic services. In this paper, we present the results of a survey among electronic service stakeholder groups, to identify the most important barriers to electronic service development. Documentation of barriers is considered important, since administrations may take certain measures to overcome them. Hints on how specific barriers may be overcome are also provided.}, doi = {10.2979/esj.2005.4.1.41}, author = {Costas Vassilakis and Giorgos Lepouras and John Fraser and Simon Haston} } @article {Vassilakis200581, title = {Exploiting form semantics and validation checks to improve e-form layout}, journal = {International Journal of Web Engineering and Technology}, volume = {2}, number = {1}, year = {2005}, note = {cited By (since 1996) 0}, pages = {81-96}, abstract = {On their route to the electronic era, organisations release on the web more and more complex form-based services, which require users to enter numerous data items interrelated by business rules. In such a context, it is crucial to provide optimal form layouts, in order to present the service users with interfaces that facilitate their work. This paper presents an integrated environment, which exploits data item interrelations manifested by the business rules (or validation checks), to optimise the layout of the web forms comprising a complex service. The approach is validated through its application on a tax return form e-service. Copyright Β{\textcopyright} 2005 Inderscience Enterprises Ltd.}, keywords = {electronic services, Form layout, Form semantics, Integrated environment, Interfaces (computer), Optimization, semantics, Taxation, Usuability, Validation checks, World Wide Web}, doi = {10.1504/IJWET.2005.007465}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-24344507764\&partnerID=40\&md5=e94b487785303410cb7bf88df9d12c86}, author = {Costas Vassilakis and Giorgos Lepouras and S. Rouvas and P. Georgiadis} } @article {DBLP:journals/eg/VassilakisLHL05, title = {An XML model for electronic services}, journal = {Electronic Government}, volume = {2}, number = {1}, year = {2005}, pages = {41-55}, abstract = {With the need for electronic services to be developed and deployed more and more rapidly, it is imperative that concrete models of electronic services are developed, to facilitate systematic work of electronic service stakeholders, concrete semantics and coherent representations across services developed within an organisation. Using the XML language to develop such a model, offers a number of additional advantages, such as rich semantics, facilitation of data interchange, extensibility, high abstraction levels and possibility for mechanical processing. In this paper we present the design aspects of an XML model for electronic services, which has been used for building a repository of interlinked elements representing e-services. A web-based interface for the management of this repository and a tool for automatically compiling e-service descriptions into executable images have been developed alongside. The model has been evaluated by a mixture of electronic service stakeholders, and the results of this evaluation are also presented.}, doi = {10.1504/EG.2005.006647}, author = {Costas Vassilakis and Giorgos Lepouras and C. Halatsis and Tomas Pariente Lobo} } @conference {Weir2004152, title = {Content enrichment through dynamic annotation}, booktitle = {ICEIS 2004 - Proceedings of the Sixth International Conference on Enterprise Information Systems}, year = {2004}, note = {cited By (since 1996) 0}, month = {4}, pages = {152-157}, abstract = {This paper describes a technique for interceding between users and the information that they browse. This facility, that we term {\textquoteright}dynamic annotation{\textquoteright}, affords a means of editing Web page content {\textquoteright}on-the-fly{\textquoteright} between the source Web server and the requesting client. Thereby, we have a generic way of modifying the content displayed to local users by addition, removal or reorganising any information sourced from the World-Wide Web, whether this derives from local or remote pages. For some time, we have been exploring the scope for this device and we believe that it affords many potential worthwhile applications. Here, we describe two varieties of use. The first variety focuses on support for individual users in two contexts (second-language support and second language learning). The second variety of use focuses on support for groups of users. These differing applications have a common goal which is content enrichment of the materials placed before the user. Dynamic annotation provides a potent and flexible means to this end.}, keywords = {Content based retrieval, Content enrichment, Dynamic annotation, Information analysis, Knowledge based systems, Learning systems, Servers, Web browsers, World Wide Web}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-8444234304\&partnerID=40\&md5=1ba0d141296de4e5b8bbd76ba0d1d79a}, author = {G.R.S. Weir and Giorgos Lepouras and Costas Vassilakis}, editor = {I. Seruca and J. Filipe and S. Hammoudi and J. Cordeiro} } @article {DBLP:journals/eg/VassilakisLRG04, title = {Integrating e-government public transactional services into public authority workflows}, journal = {Electronic Government}, volume = {1}, number = {1}, year = {2004}, pages = {49-60}, abstract = {Documents submitted by citizens through electronic services deployed in the context of e-Government must usually undergo processing by some organisational information system, in order to complete the citizens? requests and for the reply to be returned to the citizen. The integration, however, of the e-service delivery platform and the organisational information system is often hindered for a number of reasons, including security considerations, platform diversity or idiosyncrasies of legacy information systems. In this paper we present a generic method for providing seamless communication between the two platforms, enabling the full integration of documents submitted through electronic services into the organisational workflow, leveraging thus the quality of services offered to the citizens and facilitating e-service development and operation.}, doi = {10.1504/EG.2004.004136}, author = {Costas Vassilakis and Giorgos Lepouras and S. Rouvas and P. Georgiadis} } @article {1009361, title = {Real exhibitions in a virtual museum}, journal = {Virtual Reality}, volume = {7}, number = {2}, year = {2004}, pages = {120{\textendash}128}, publisher = {Springer-Verlag}, address = {London, UK}, abstract = {When creating a virtual environment open to the public a number of challenges have to be addressed. The equipment has to be chosen carefully in order to be be able to withstand hard every-day usage, the application has not only to be robust and easy to use, but has also to be appealing to the user, etc. The current paper presents findings gathered from the creation of a multi-thematic virtual museum environment to be offered to visitors of real world museums. A number of design and implementation aspects are described along with an experiment designed to evaluate alternative approaches for implementing the navigation in a virtual museum environment. The paper is concluded with insights gained from the development of the Virtual Museum and portrays future research plans.}, issn = {1359-4338}, doi = {10.1007/s10055-004-0121-5}, url = {https://link.springer.com/article/10.1007/s10055-004-0121-5}, author = {Giorgos Lepouras and Akrivi Katifori and Costas Vassilakis and D. Charitos} } @conference {Lep2004d, title = {Reusability in Electronic Services Development}, booktitle = {Proceedings of the CSITeA 04 conference}, year = {2004}, month = {12}, abstract = {Electronic government employs electronic services to facilitate interaction with citizens and enterprises and deliver a rich and high quality spectrum of services. Development of electronic services can be greatly assisted, both in terms of development cost and roll-out time, by exploiting the reusability inherent in them. Reusability may be promoted by identifying reusable objects in the context of electronic service development, building and populating a repository with such components and providing the means for developers to locate, extract and adapt them to suit the task at hand. In this paper we analyse electronic services to recognise reusable components and present means and techniques that empower electronic service developers to build electronic services through reusable components.}, author = {Costas Vassilakis and Giorgos Lepouras} } @conference {Lepouras_tailorabilityin, title = {Tailorability in the context of E-government Information Systems: An approach}, booktitle = {Proceedings of the IRMA 2004 conference}, year = {2004}, month = {5}, abstract = {The ever changing environment information systems model, and in particular e-government ones, intensifies the need for systems that are able to easily, efficiently and transparently adapt to changing environments. Accommodating unanticipated changes implies that systems must be able to adapt to changes occurring in and evolve in step with their changing environment. Adaptation is concerned with monitoring, analysing and understanding the patterns of the user{\textquoteright}s interaction with the system. Similarly, an information system is said to be evolutionary if it can be purposefully used in a dynamic environment. E-government information systems, in virtue of their nature and function, are driven by the need to adapt and evolve. This suggests that the design and implementation of such systems must provide the necessary infrastructure for evolution and adaptability. In other words, e-government information systems must abide to the Tailorable Information Systems paradigm. In this work we present a case study for the development of a Tailorable e-government information system.}, author = {Giorgos Lepouras and Anya Sotiropoulou and Dimitrios Theotokis and Costas Vassilakis} } @article {Lepouras200596, title = {Virtual museums for all: Employing game technology for edutainment}, journal = {Virtual Reality}, volume = {8}, number = {2}, year = {2004}, note = {cited By (since 1996) 10}, month = {jun}, pages = {96{\textendash}106}, publisher = {Springer Nature}, abstract = {Museums have started to realise the potential of new technologies for the development of edutainment content and services for their visitors. Virtual reality technologies promise to offer a vivid, enjoyable experience to the museums guests, but the cost in time, effort and resources can prove to be overwhelming. In this paper, we propose the use of 3D game technologies for the purpose of developing affordable, easy to use and pleasing virtual environments. To this end, we present a case study based on an already developed version of a virtual museum and a newly implemented version that uses game technologies. The informal assessment indicates that game technologies can offer a prominent and viable solution to the need for affordable desktop virtual reality systems. Β{\textcopyright} Springer-Verlag London Limited 2004.}, doi = {10.1007/s10055-004-0141-1}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-22144472250\&partnerID=40\&md5=c0200e7737345b0757026dbcb3040cf9}, author = {Giorgos Lepouras and Costas Vassilakis} } @conference {gorilas2003, title = {E-forms services for the Public Sector: Shifting Development Effort from Programmers to Domain Experts}, booktitle = {Proceedings of e-Challenges 2003}, year = {2003}, month = {10}, abstract = {E-forms have a central role in a significant number of e-government services. This paper presents a knowledge-based technical platform aiming to assist public sector employees to generate online transaction services by simplifying their development, maintenance and integration with installed IT systems. At the heart of this platform lies the knowledge and transaction services repository. This repository consists of a number of XML document types that incorporate all necessary details for creating and managing online transaction services. The main underlying idea is to provide a platform with intuitive interfaces that can be used directly by domain experts thus minimising the need for personnel with IT skills. This platform is currently under development within the IST SmartGov project.}, author = {Stelios Gorilas and Costas Vassilakis and Tomas Pariente Lobo and E. Tambouris} } @conference {lep03a, title = {Facilitating VR Museums Web Presence}, booktitle = {Proceedings of HCI 2003}, year = {2003}, month = {6}, pages = {1143{\textendash}1147}, abstract = {The paper presents an environment that enables museum curators to catalogue and publish on the web exhibits in multiple languages and media including 3D, video, images. The system is extendable to accommodate new media types, languages, exhibits, information categories, etc. Visitors have the potential to formulate dynamic personalised exhibit collections using search mechanisms provided by the system.}, author = {Giorgos Lepouras and Akrivi Katifori and Costas Vassilakis and Anna Charissi} } @article {Vassilakis2003315, title = {A framework for managing the lifecycle of transactional e-government services}, journal = {Telematics and Informatics}, volume = {20}, number = {4}, year = {2003}, note = {cited By (since 1996) 13}, pages = {315-329}, abstract = {Filling and submission of electronic forms is a key issue for e-government, since most electronic services offered in this context include some variant of electronic forms. Insofar, IT experts are placed in the centre of electronic forms services lifecycles, undertaking the analysis, design, implementation and maintenance phases. This practice, however, implies various impediments, such as the need for multitudinous teams with diverse skills. In this paper, we present experiences from developing and maintaining a set of electronic services for the Greek Ministry of Finance, and propose an approach to handling electronic services{\textquoteright} lifecycle that balances responsibilities between domain experts and IT professionals. This approach enables a more holistic management of the electronic service lifecycle, by employing modelling and representation in high levels of abstraction and incorporating tools for automatically generating operative service instances from these high-level descriptions. Β{\textcopyright} 2003 Elsevier Science Ltd. All rights reserved.}, keywords = {Communication, Electronic forms, Information science, Information technology}, doi = {10.1016/S0736-5853(03)00011-X}, url = {https://www.sciencedirect.com/science/article/abs/pii/S073658530300011X}, author = {Costas Vassilakis and Laskaridis, G. and Giorgos Lepouras and S. Rouvas and P. Georgiadis} } @conference {DBLP:conf/caise/VassilakisLRG03, title = {Improving e-Form Layout Through Analysis of Form Semantics and Validation Checks}, booktitle = {CAiSE Short Paper Proceedings}, year = {2003}, month = {6}, abstract = {Transaction services offered by public authorities vary from simple forms with few fields to multi-form compound documents with hundreds of input areas. In the latter case, field placement within forms is of particular importance for facilitating the filling and error correction processes. In this paper we present an approach to improving the form layout by exploiting validation checks that are usually associated with electronic forms, as well as semantic information that may be attached to form fields by designers.}, url = {http://ceur-ws.org/Vol-74/files/FORUM_38.pdf}, author = {Costas Vassilakis and Giorgos Lepouras and S. Rouvas and P. Georgiadis} } @proceedings {DBLP:conf/chorochronos/2003, title = {Spatio-Temporal Databases: The CHOROCHRONOS Approach}, volume = {2520}, year = {2003}, publisher = {Springer}, isbn = {3-540-40552-6}, doi = {10.1007/b83622}, url = {https://doi.org/10.1007/b83622}, editor = {Manolis Koubarakis and Timos K. Sellis and Andrew U. Frank and St{\'e}phane Grumbach and Ralf Hartmut G{\"u}ting and Christian S. Jensen and Nikos A. Lorentzos and Yannis Manolopoulos and Enrico Nardelli and Barbara Pernici and Hans-J{\"o}rg Schek and Michel Scholl and Babis Theodoulidis and Nectaria Tryfona} } @article {Lepouras2003248, title = {A system to support dissemination of knowledge and sharing of experiences in the working environment: Review Code 066}, journal = {International Journal of Continuing Engineering Education and Lifelong Learning}, volume = {13}, number = {3/4}, year = {2003}, pages = {248-257}, publisher = {Inderscience Publishers}, abstract = {In the information era, enterprises strive to be productive and efficient. One feature of this goal is for employers to engage their employees in education programs, to help them to gain new experiences and knowledge and to adapt to an ever-changing working environment. Such programs must be carefully designed in order to achieve satisfactory results. Recently, enterprises, recognising the role that technology can play in the education of their employees, have adopted systems that supplement the traditional educational model with mechanisms that enable the sharing of experiences and knowledge. In this paper we describe an architecture and a system prototype that allows users to search easily for information, interact with colleagues and share experiences, and to compose and disseminate best practices and knowledge. The design of this system is based on insights gained from the operation of the Greek taxation system.}, keywords = {Education computing, Engineering education, Information dissemination, Integrated systems, Knowledge based systems, Systems analysis}, doi = {10.1504/ijceell.2003.003277}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0041975974\&partnerID=40\&md5=3fdaf5e728f5571c01c70507e0ad7004}, author = {Giorgos Lepouras and Costas Vassilakis and G.R.S. Weir} } @conference {756327, title = {Controlled Caching of Dynamic WWW Pages}, booktitle = {DEXA {\textquoteright}02: Proceedings of the 13th International Conference on Database and Expert Systems Applications}, year = {2002}, month = {9}, pages = {9{\textendash}18}, publisher = {Springer-Verlag}, organization = {Springer-Verlag}, address = {London, UK}, abstract = {Web sites employ dynamically generated pages for content delivery more and more often, in order to increase their flexibility and provide up-to-date information. This practice, however, increases server load dramatically, since each request results to the execution of code, which may involve processing and/or access to information repositories. In this paper we present a scheme for maintaining a server-side cache of dynamically generated pages, allowing for cache consistency maintenance, without placing heavy burdens on application programmers. We also present insights to architecture scalability and some results obtained from conducted experiments.}, isbn = {3-540-44126-3}, doi = {10.1007/3-540-46146-9_2}, url = {http://link.springer.com/chapter/10.1007\%2F3-540-46146-9_2}, author = {Costas Vassilakis and Giorgos Lepouras} } @proceedings {DBLP:conf/dmdw/2002, title = {Design and Management of Data Warehouses 2002, Proceedings of the 4th Intl. Workshop DMDW{\textquoteright}2002, Toronto, Canada, May 27, 2002}, volume = {58}, year = {2002}, publisher = {CEUR-WS.org}, url = {http://ceur-ws.org/Vol-58}, editor = {Laks V. S. Lakshmanan} } @conference {649749, title = {Serving Enhanced Hypermedia Information}, booktitle = {Proceedings of the 24th BCS-IRSG European Colloquium on IR Research}, year = {2002}, month = {3}, pages = {86{\textendash}92}, publisher = {Springer-Verlag}, organization = {Springer-Verlag}, address = {London, UK}, abstract = {An apparent limitation of existing Web pages is their inability to accommodate differences in the interests and needs of individual users. The present paper describes an approach that dynamically customises the content of public Web-based information via an interceding {\textquoteright}enhancement server{\textquoteright}. The design and operation of this system is described with examples drawn from two current versions. Indications from early trials support the view that this approach affords considerable scope for accommodating the needs and interests of individual Web users.}, isbn = {3-540-43343-0}, doi = {10.1007/3-540-45886-7_6}, author = {Giorgos Lepouras and Costas Vassilakis and G.R.S. Weir} } @conference {lep2002a1, title = {SMARTGOV: A Governmental Knowledge-based Platform for Public Sector Online Services}, booktitle = {Proceedings KMGov2002}, year = {2002}, month = {5}, pages = {173{\textendash}185}, address = {Copenhagen, Denmark}, abstract = {Public transaction services (such as e-forms), although perceived the future of e-government have not yet realised their full potential. E-forms have a significant role in e-government, as they are the basis for realising most of the twenty public services that all European Union member states have to provide to their citizens and businesses. The aim of this paper is to present a knowledge-based platform to assist public sector employees to generate online transaction services by simplifying their development, maintenance and integration with already installed IT systems.}, author = {E. Tambouris and G. Boukis and Costas Vassilakis and Giorgos Lepouras and S. Rouvas and Canadas, R. and Heredia, S. and Lopez Usero, J. C.} } @conference {Georgiadis_2002, title = {SmartGov: A Knowledge-Based Platform for Transactional Electronic Services}, booktitle = {Lecture Notes in Computer Science}, year = {2002}, month = {9}, pages = {362-369}, publisher = {Springer Berlin Heidelberg}, organization = {Springer Berlin Heidelberg}, abstract = {Public transaction services (such as e-forms) although perceived the future of e-government have not yet realised their full potential. E-forms have a significant role in e-government, as they are the basis for implementing most of the twenty public services that all member states have to provide to their citizens and businesses. The aim of the SmartGov project is to specify, develop, deploy and evaluate a knowledge-based platform to assist public sector employees to generate online transaction services by simplifying their development, maintenance and integration with already installed IT systems. This platform will be evaluated in two European countries (in one Ministry and one Local Authority). This paper outlines key issues in the development of the SmartGov system platform.}, doi = {10.1007/978-3-540-46138-8_59}, url = {https://link.springer.com/chapter/10.1007/978-3-540-46138-8_59}, author = {P. Georgiadis and Giorgos Lepouras and Costas Vassilakis and G. Boukis and E. Tambouris and S. Gorilas and E. Davenport and A. Macintosh and J. Fraser and D. Lochhead} } @conference {650426, title = {Transactional e-Government Services: An Integrated Approach}, booktitle = {EGOV {\textquoteright}02: Proceedings of the First International Conference on Electronic Government}, year = {2002}, month = {9}, pages = {276{\textendash}279}, publisher = {Springer-Verlag}, organization = {Springer-Verlag}, address = {London, UK}, abstract = {Although form-based transactional services are fundamental to electronic government activities, their widespread does neither meet the citizen{\textquoteright}s expectations, nor the potential offered by state-of-the-art technologies. Besides any bureaucratic impediments, the primary reason for this is that traditional software engineering approaches cannot satisfactorily handle all the aspects of electronic services lifecycle. In this paper we present experiences from developing and maintaining a set of electronic services for the Greek Ministry of Finance, and propose a new approach for handling electronic service projects. The proposed approach has been successfully employed for developing extensions to the existing services, as well as some new ones.}, isbn = {3-540-44121-2}, doi = {10.1007/978-3-540-46138-8_44}, url = {http://link.springer.com/chapter/10.1007\%2F978-3-540-46138-8_44}, author = {Costas Vassilakis and Laskaridis, G. and Giorgos Lepouras and S. Rouvas and P. Georgiadis} } @conference {Lep01a, title = {Building a VR - Museum in a Museum}, booktitle = {Proceedings of the Third International Virtual Reality Conference, VRIC2001}, year = {2001}, month = {5}, abstract = {Past years have seen the exploitation of multimedia techniques and lately the introduction of virtual reality methods to create new forms of presentation for museums{\textquoteright} exhibitions. Virtual Reality can offer a number of advantages to museums, offering a way to overcome some common problems like the lack of space or the need of visitors to interact with the exhibits. A broad categorisation of virtual museums reveals that they vary from fully immersive cave systems to simple multimedia presentations. In our approach to develop a virtual reality museum we have designed a virtual environment (VE) where guests can visit a total of ten different museums. The processes of digitisation, architectural design and exhibit presentation are outlined and points of particular importance are explained. Exhibits from the real world museums have been digitised and integrated in the VE. The system has been implemented in two versions: one fully immersive and one with a stereo display.}, author = {Giorgos Lepouras and D. Charitos and Costas Vassilakis and Charissi, A. and Halatsi, L.} } @conference {Charitos2001284, title = {Designing a virtual museum within a museum}, booktitle = {Proceedings VAST 2001 Virtual Reality, Archeology, and Cultural Heritage}, year = {2001}, note = {cited By (since 1996) 0}, month = {11}, pages = {284}, abstract = {The designing of a virtual museum within a museum was discussed. In regard with it, the Virtual Museum project sponsored by the Greek General Secretariat of Research and Technology was presented. The project{\textquoteright}s main objective was to create a virtual environment (VE) for enhancing the experience of visiting a museum by affording view and manipulation of certain exhibits.}, keywords = {Information retrieval systems, Internet, Museums, Technical presentations, Three dimensional computer graphics, Virtual museum, Virtual reality}, doi = {10.1145/584993.585043}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0141426770\&partnerID=40\&md5=50066081a4e5d55bfc3c823813535add}, author = {D. Charitos and Giorgos Lepouras and Costas Vassilakis and Akrivi Katifori and Charissi, A. and Halatsi, L.}, editor = {S. N. Spencer} } @conference {Lask2001a, title = {e-Citizens and e-Consumers: Is There a Difference?}, booktitle = {Proceedings of the PCHCI 2001 Workshop: "Transforming Web Surfers to E-Shoppers"}, year = {2001}, month = {12}, pages = {47-50}, abstract = {Both the business sector and the government are nowadays embracing Internet technologies in order to provide high quality on-line services to their "target groups". In both cases, service providers are trying to transform web surfers, casually visiting their web sites to seek information, to users of their electronic services, i.e. e-consumers and. e-citizens. In this paper, we address the similarities and the differences between the business and the government, when they act as service providers, with respect to the factors for successful service and the issues that must be addressed.}, author = {Laskaridis, G. and Costas Vassilakis and Giorgos Lepouras and S. Rouvas} } @conference {Dimitrios00anapproach, title = {An Approach to Designing and Implementing Virtual Museums}, booktitle = {Proceedings of the seventh UK VR-SIG Conference}, year = {2000}, month = {9}, abstract = {The current paper describes an approach to designing and implementing a virtual environment comprising ten different museums. The number of museums as well as the variety of their exhibits lead to the adoption of a generalised strategy that catered for all museum presentation needs and allowed for future expansion. Furthermore, the system architecture supports the delivery of multimedia content either over the Internet or via a local immersive virtual reality installation.}, author = {D. Charitos and Giorgos Lepouras and Costas Vassilakis and Akrivi Katifori and C. Halatsis} } @conference {Lep2000a, title = {Multilingual Web Site Construction and Maintenance}, booktitle = {Proceedings of the SCI 2000 conference}, year = {2000}, month = {7}, pages = {56-61}, abstract = {The construction of multilingual web sites is probably the best answer to addressing the problem of the diverse cultural background of the Internet community. However, developing multiple instances of the same site in different languages induces increased overhead for both the implementation and the maintenance phase. The paper reviews current techniques and describes an alternative to constructing multilingual web sites, which eases the development and maintenance phases, without possessing any of the drawbacks of existing tools. The paper concludes proposing possible future enhancements.}, author = {Giorgos Lepouras and Costas Vassilakis} } @conference {vassil99a, title = {Is Server-Side Programming Killing Your Web Server?}, booktitle = {Proceedings of the ActiveWeb 99 Conference}, year = {1999}, month = {10}, address = {Staffordshire University}, abstract = {The paper addresses issues related to client/server technologies and specifically the effectiveness of server-side programming techniques. The motive for this study was the need to create a lightweight and dynamic navigational aid for use in a web site. Towards this goal a number of possible solutions were considered and for two of them an experiment was run to determine the best suited for our case. The rest of the paper outlines our findings.}, url = {http://www.visualize-uk.com/conf/activeweb/proceed/pap7/}, author = {Costas Vassilakis and Giorgos Lepouras} } @article {Vassilakis1998335, title = {Implementation of transaction and concurrency control support in a temporal DBMS}, journal = {Information Systems}, volume = {23}, number = {5}, year = {1998}, note = {cited By (since 1996) 2}, pages = {335{\textendash}350}, abstract = {Transactions and concurrency control are significant features in database systems, facilitating functions both at user and system level. However, the support of these features in a temporal DBMS has not yet received adequate research attention. In this paper, we describe the techniques developed in order to support transaction and concurrency control in a temporal DBMS that was implemented as an additional layer to a commercial DBMS. The proposed techniques make direct use of the transaction mechanisms of the DBMS. In addition, they overcome a number of limitations such as automatic commit points, lock release and log size increment, which are imposed by the underlying DBMS. Our measurements have shown that the overhead introduced by these techniques is negligible, less than 1\% in all cases. The approach undertaken is of general interest, it can also be applied to non-temporal DBMS extensions. Copyright Β{\textcopyright} 1998 Elsevier Science Ltd. All rights reserved.}, keywords = {Concurrency control, Data structures, Database systems, Temporal databases}, doi = {10.1016/S0306-4379(98)00015-5}, url = {https://doi.org/10.1016/S0306-4379(98)00015-5}, author = {Costas Vassilakis and N. Lorentzos and P. Georgiadis} } @conference {719700, title = {Transaction Support in a Temporal DBMS}, booktitle = {Proceedings of the International Workshop on Temporal Databases}, year = {1995}, month = {9}, pages = {255{\textendash}271}, publisher = {Springer-Verlag}, organization = {Springer-Verlag}, address = {London, UK}, abstract = {Transactions are a significant concept in database systems, facilitating functions both at user and system level. However transaction support in temporal DBMSs has not yet received enough research attention. In this paper, we present techniques for incorporating transaction support in a temporal DBMS, which is implemented as an additional layer to a commercial RDBMS. These techniques overcome certain limitations imposed by the underlying RDBMS, and avoid excessive increment of the log size.}, isbn = {3-540-19945-4}, doi = {10.1007/978-1-4471-3033-8_14}, url = {http://link.springer.com/chapter/10.1007\%2F978-1-4471-3033-8_14}, author = {Costas Vassilakis and N. Lorentzos and P. Georgiadis} } @conference {1993-vassilakis-hci, title = {A Methodology for the Implementation of Software for the Design of Distributed Systems}, booktitle = {Proceedings of the 4th Hellenic Conference on Informatics}, year = {1993}, month = {12}, pages = {673{\textendash}686}, abstract = {As the use of distributed systems is spreading, and applications designed for such systems become more and more demanding, optimal design of distributed systems becomes a critical issue. Designing a distributed system has become more complex, due to the number of alternatives for each decision that must be made and because of the existence of many parameters which influence the overal performance of the distributed system. Thus, it is necessary to use software tools, capable of accepting a description of the user{\textquoteright}s requirements and suggesting solutions to the problem of designing a distributed system which meets the user{\textquoteright}s requirements. In this paper, we present a disciplined approach to the construction of such a software tool, which combines methods from the Artificial Intelligence domain, that are used in order to design the distributed system, along with simulation techniques, used to estimate the system{\textquoteright}s overall performance.}, author = {Costas Vassilakis and P. Georgiadis and D. Lelis and D. Mouzakis and M. Nikolaidou} }