@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 {783, title = {Threat landscape for smart grid systems}, booktitle = {Proceedings of the 15th International Conference on Availability, Reliability and Security}, year = {2020}, month = {jul}, publisher = {ACM}, organization = {ACM}, abstract = {

Smart Grids are energy delivery networks, constituting an evolution of power grids, in which a bidirectional flow between power providers and consumers is established. These flows support the transfer of electricity and information, in order to support automation actions in the context of the energy delivery network. Insofar, many smart grid implementations and implementation proposals have emerged, with varying degrees of feature delivery and sophistication. While smart grids offer many advantages, their distributed nature and information flow streams between energy producers and consumers enable the launching of a number of attacks against the smart grid infrastructure, where the related consequences may range from economic loss to complete failure of the smart grid. In this paper, we survey the threat landscape of smart grids, identifying threats that are specific to this infrastructure, providing an assessment of the severity of the consequences of each attack type, discerning features that can be utilized to detect attacks and listing methods that can be used to mitigate them.

}, keywords = {attack detection features, attack mitigation, attacks, security, Smart grids}, doi = {https://doi.org/10.1145/3407023.3409229}, author = {Christos-Minas Mathas and Konstantinos-Panagiotis Grammatikakis and Costas Vassilakis and Nicholas Kolokotronis and Vasiliki-Georgia Bilali and Dimitris Kavallieros} } @conference {Kolokotronis2019IEEESrv, title = {On Blockchain Architectures for Trust-based Collaborative Intrusion Detection}, booktitle = {Proceedings of the 1st IEEE Services Workshop on Cyber Security and Resilience in the Internet Of Things, within IEEE Services 2019}, year = {2019}, publisher = {IEEE}, organization = {IEEE}, abstract = {This paper considers the use of novel technologies for mitigating attacks that aim at compromising intrusion detection systems (IDSs). Solutions based on collaborative intrusion detection networks (CIDNs) could increase the resilience against such attacks as they allow IDS nodes to gain knowledge from each other by sharing information. However, despite the vast research in this area, trust management issues still pose significant challenges and recent works investigate whether these could be addressed by relying on blockchain and related distributed ledger technologies. Towards that direction, the paper proposes the use of a trust-based blockchain in CIDNs, referred to as trust-chain, to protect the integrity of the information shared among the CIDN peers, enhance their accountability, and secure their collaboration by thwarting insider attacks. A consensus protocol is proposed for CIDNs, which is a combination of a proof-of-stake and proof-of-work protocols, to enable collaborative IDS nodes to maintain a reliable and tampered-resistant trust-chain.}, keywords = {blockchain, collaborative intrusion detection, insider threats, security, trust management}, author = {Nicholas Kolokotronis and Sotirios Brotsis and Georgios Germanos and Costas Vassilakis and Stavros Shiaeles} } @conference {588, title = {The quest for the appropriate cyber-threat intelligence sharing platform}, booktitle = {Proceedings of the 8th International Conference on Data Science, Technology and Applications (DATA), Prague, Czech Republic}, year = {2019}, month = { 07/2009}, abstract = {Cyber-threat intelligence (CTI) is any information that can help an organization identify, assess, monitor, and respond to cyber-threats. It relates to all cyber components of an organization such as networks, computers, and other types of information technology. In the recent years, due to the major increase of cyber-threats, CTI sharing is becoming increasingly important both as a subject of research and as a concept of providing additional security to organizations. However, selecting the proper tools and platforms for CTI sharing, is a challenging task, that pertains to a variety of aspects. In this paper, we start by overviewing the CTI procedure (threat types, categories, sources and the general CTI life-cycle). Then, we present a set of seven high-level CTI platform recommendations that can be used to evaluate a platform and subsequently we survey six state-of- the-art cyber-threat intelligence platforms. Finally, we compare and evaluate the six aforementioned platforms by means of the earlier proposed recommendations.}, keywords = {Cyber-threat, Intelligence, Sharing}, url = {http://users.uop.gr/~trifon/papers/pdf/data19-CKSKTBK.pdf}, author = {Thanasis Chantzios and Paris Koloveas and Spiros Skiadopoulos and Nikos Kolokotronis and Christos Tryfonopoulos and Vasiliki-Georgia Bilali and Dimitris Kavallieros} } @conference {DBLP:conf/ssdbm/KaffesBSS18, title = {Finding shortest keyword covering routes in road networks}, booktitle = {Proceedings of the 30th International Conference on Scientific and Statistical Database Management, SSDBM 2018, Bozen-Bolzano, Italy, July 09-11, 2018}, year = {2018}, pages = {12:1{\textendash}12:12}, doi = {10.1145/3221269.3223038}, url = {https://doi.org/10.1145/3221269.3223038}, author = {Vassilis Kaffes and Alexandros Belesiotis and Dimitrios Skoutas and Spiros Skiadopoulos} } @proceedings {DBLP:conf/ssdbm/2018, title = {Proceedings of the 30th International Conference on Scientific and Statistical Database Management, SSDBM 2018, Bozen-Bolzano, Italy, July 09-11, 2018}, year = {2018}, publisher = {ACM}, doi = {10.1145/3221269}, url = {https://doi.org/10.1145/3221269}, editor = {Dimitris Sacharidis and Johann Gamper and Michael H. B{\"o}hlen} } @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 {boukoros2017, title = {Modeling Server Workloads for Campus Email Traffic Using Recurrent Neural Networks}, booktitle = {Proceedings of the 24th International Conference on Neural Information Processing (ICONIP 2017)}, year = {2017}, pages = {57{\textendash}66}, publisher = {Springer International Publishing}, organization = {Springer International Publishing}, abstract = {As email workloads keep rising, email servers need to handle this explosive growth while offering good quality of service to users. In this work, we focus on modeling the workload of the email servers of four universities (2 from Greece, 1 from the UK, 1 from Australia). We model all types of email traffic, including us-er and system emails, as well as spam. We initially tested some of the most popu-lar distributions for workload characterization and used statistical tests to evaluate our findings. The significant differences in the prediction accuracy results for the four datasets led us to investigate the use of a Recurrent Neural Network (RNN) as time series modeling to model the server workload, which is a first for such a problem. Our results show that the use of RNN modeling leads in most cases to high modeling accuracy for all four campus email traffic datasets.}, keywords = {Email traffic, Model server workload, Recurrent neural network, Time series modeling}, doi = {10.1007/978-3-319-70139-4_6}, author = {Spyros Boukoros and Anupiya Nugaliyadde and Angelos Marnerides and Costas Vassilakis and Polychronis Koutsakis and Kok Wai Wong} } @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 {575, title = {R-Susceptibility: An IR-Centric Approach to Assessing Privacy Risks for Users in Online Communities}, booktitle = {Proceedings of the 39th Annual International ACM SIGIR Conference}, year = {2016}, month = {July}, address = {Pisa, Italy}, author = {Joanna Asia Biega and Krishna P. Gummadi and Ida Mele and Dragan Milchevski and Christos Tryfonopoulos and Gerhard Weikum} } @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} } @proceedings {DBLP:conf/kcap/2015, title = {Proceedings of the 8th International Conference on Knowledge Capture, K-CAP 2015, Palisades, NY, USA, October 7-10, 2015}, year = {2015}, publisher = {ACM}, isbn = {978-1-4503-3849-3}, doi = {10.1145/2815833}, url = {https://doi.org/10.1145/2815833}, editor = {Ken Barker and Jos{\'e} Manu{\'e}l G{\'o}mez-P{\'e}rez} } @proceedings {DBLP:conf/pkdd/2013-3, title = {Machine Learning and Knowledge Discovery in Databases - European Conference, ECML PKDD 2013, Prague, Czech Republic, September 23-27, 2013, Proceedings, Part III}, volume = {8190}, year = {2013}, publisher = {Springer}, isbn = {978-3-642-40993-6}, doi = {10.1007/978-3-642-40994-3}, url = {https://doi.org/10.1007/978-3-642-40994-3}, editor = {Hendrik Blockeel and Kristian Kersting and Siegfried Nijssen and Filip Zelezn{\'y}} } @article {benou2012b, title = {A context management architecture for m-commerce applications}, journal = {Central European Journal of Computer Science, Versita, co-published with Springer Verlag}, volume = {2}, number = {2}, year = {2012}, pages = {87{\textendash}117}, abstract = {Mobile commerce applications operate in highly dynamic environments with diverse characteristics and interesting challenges. The characteristics and conditions of these environments {\textendash}called context{\textendash}, can be exploited to provide adaptive mobile services, in terms of user interface, functionality and content, in order to offer more effective m-commerce. Today, building adaptive mobile services is a complex and time-consuming task due to the lack of standardized methods, tools and architectures for the identification, representation and management of the context. Addressing some of these issues, recent works have provided formal extensions for various stages of the m-commerce application lifecycle, such as extended UML class diagrams for building design models and have used context parameters in order to offer adaptive applications. Using these works as the basis, in this paper we propose a context management architecture, which accommodates the requirements that have been identified for m-commerce applications. The proposed architecture is evaluated in terms of completeness, complexity, performance and utility, and compared against other approaches proposed in the literature regarding its suitability for supporting context-aware m-commerce applications.}, keywords = {adaptivity, context, context management, context-awareness, mobile commerce, software architecture}, doi = {10.2478/s13537-012-0010-z}, url = {https://link.springer.com/article/10.2478/s13537-012-0010-z}, author = {Poulcheria Benou and Costas Vassilakis} } @article {benou2012, title = {Context Management for m-Commerce Applications: Determinants, Methodology and the Role of Marketing}, journal = {Information Technology and Management, Springer-Verlag}, volume = {13(2)}, year = {2012}, pages = {91 {\textendash} 111}, abstract = {Studying consumer behaviour and usage of environmental determinants in the mobile services domain contributes to the identification of context information which is critical for the effective operation of mobile commerce applications. Exploiting this information towards providing enhanced and innovative mobile services offers a competitive advantage within the highly demanding domain of m-commerce applications. However, in order to effectively exploit such context information, there is a need to design the necessary methods, software tools and information systems that will be employed for collecting, processing and disseminating this information. In this paper we develop a theoretical framework which defines the context information necessary for m-commerce applications, taking into account relevant marketing dimensions as well as privacy protection perspectives. Then, this framework is operationalized through the design of an appropriate software architecture which enables the standardization and management of context information.}, doi = {10.1007/s10799-012-0120-2}, author = {Poulcheria Benou and Costas Vassilakis and Adam Vrechopoulos} } @article {DBLP:journals/tkde/BourosSDSS12, title = {Evaluating Path Queries over Frequently Updated Route Collections}, journal = {IEEE Trans. Knowl. Data Eng.}, volume = {24}, number = {7}, year = {2012}, pages = {1276{\textendash}1290}, doi = {10.1109/TKDE.2011.30}, url = {https://doi.org/10.1109/TKDE.2011.30}, author = {Panagiotis Bouros and Dimitris Sacharidis and Theodore Dalamagas and Spiros Skiadopoulos and Timos K. Sellis} } @mastersthesis {526, title = {A Software Development Methodology and a Software Architecture for Context-Aware M-Commerce Applications}, volume = {Ph.D. thesis}, year = {2012}, month = {02/2012}, pages = {369}, school = {University of the Peloponnese}, type = {Doctoral}, address = {Tripolis}, abstract = {

Mobile commerce is gaining importance in the recent years, as an enhanced version of e-commerce for the moving user. The mobile services through which m-commerce takes place operate in highly dynamic environments with diverse characteristics and under varying conditions. The characteristics and conditions of these environments {\textendash}called context{\textendash} can be exploited in order to offer a suitable user experience and deliver innovative and enhanced mobile services that will facilitate user interaction, attract new customers and maintain existing ones. Therefore, mobile commerce applications adhering to {\textquotedblleft}anytime and anywhere{\textquotedblright} paradigm are required to be flexible. They should be able to adapt their user-perceived constituent parts, i.e. their interface, services and content towards a certain context. Several proposals for definition of context have been already proposed originating from various areas related to mobile commerce. However, an integrated, formal and methodological approach for the determination and representation of context, adjusted to special characteristics of mobile commerce applications, has not been insofar presented. This is one challenge we address in this thesis, through a conceptual model that includes: i) a clear and formal definition of context, ii) the depiction of its specific characteristics as metadata, iii) a methodology for its determination and iv) the presentation of an extension of UML class and case diagrams for its representation, all of them tailored to the special nature of mobile commerce applications.

Once the context information for an m-commerce application has been determined, the next step in order to achieve the goal of adaptivity is to capture the context information from its sources, process and distribute it to the software components that will use it. In order to offer a complete suite of tools for context management, we propose a software architecture for context information management suitable for m-commerce applications. We describe the functionality and characteristics of its components, as well as the interaction among these different components.

The usage of context information in order to achieve the ultimate goal of adaptivity should be done from a subsystem designed in such way that will simplify and homogenize the relevant processes and at the same time promote the independence of the code of the main application from the adaptation code. Addressing this issue, in this thesis we propose an approach for developing adaptive mobile commerce applications, adhering to the separation of concerns principle, which is offered by the aspect-oriented paradigm. By clearly separating the work required for the development of the application logic from that required for enabling application{\textquoteright}s adaptive behavior, this approach reduces the development effort and at the same time promotes the flexibility, manageability and maintainability of adaptive m-commerce applications. }, keywords = {Context Information, context management, context-awareness, mobile commerce, Mobile Commerce Applications, Software Adaptation, Software Architecture for M-commerce Applications, Software Methodology for M-commerce Applications}, url = {https://soda.dit.uop.gr/sites/soda.dit.uop.gr/files//Benou_PhDThesis.pdf}, author = {Poulcheria Benou}, editor = {Costas Vassilakis} } @conference {benou2011a, title = {A Software Architecture for Provision of Context-Aware Web-based m-Commerce Applications}, booktitle = {Proceedings of the 11th IEEE International Conference on Computer and Information Technology (CIT 2011)}, year = {2011}, month = {8}, publisher = {IEEE Computer Society}, organization = {IEEE Computer Society}, abstract = {Mobile commerce is gaining significant importance in the recent years as an alternative option of e-commerce for the moving user. The mobile applications through which mcommerce takes place operate in highly dynamic environments with diverse characteristics and under varying conditions. The characteristics and conditions of these environments {\textendash}called context{\textendash} should be exploited in order to provide adaptive services; services that offer a suitable user experience and deliver innovative and enhanced capabilities that will facilitate user interaction, attract new customers and maintain existing ones. The goal of adaptivity is realized through the adaptation of user interface, functionality and content of applications using the context information. Therefore, context-awareness constitutes an essential aspect {\textendash} almost a requirement {\textendash} of mobile services. In order to realize context-aware services, there is a necessity to capture the context information from its sources, process and distribute it to the software components that will use it. In this paper, we propose a software architecture for context information management suitable for m-commerce applications. We describe the functionality and characteristics of its components, as well as the interaction among these different components}, doi = {10.1109/CIT.2011.20}, author = {Poulcheria Benou and Costas Vassilakis} } @article {benou2010, title = {The Conceptual Model of Context for Mobile Commerce Applications}, journal = {Electronic Commerce Research, Springer-Verlag}, volume = {10(2)}, year = {2010}, pages = {139-165}, abstract = {Mobile commerce applications adhering to anytime and anywhere paradigm, required to be flexible. They should be able to adapt their interface, services and content towards a certain context. Several proposals for definition of context have been already proposed originating from various areas related to mobile commerce. However, an integrated, formal and methodological approach for the determination and representation of context, adjusted to special characteristics of mobile commerce applications, has not been insofar presented. This is the challenge we address in this paper, through a conceptual model that includes: i) a clear and formal definition of context, ii) the depiction of its specific characteristics as metadata, iii) a methodology for its determination and iv) the presentation of an extension of class diagrams of UML for its representation, all of them tailored to the special nature of mobile commerce applications.}, doi = {10.1007/s10660-010-9050-4}, author = {Poulcheria Benou and Costas Vassilakis} } @article {DBLP:journals/tkde/ClementiniSBT10, title = {A Reasoning System of Ternary Projective Relations}, journal = {IEEE Trans. Knowl. Data Eng.}, volume = {22}, number = {2}, year = {2010}, pages = {161{\textendash}178}, doi = {10.1109/TKDE.2009.79}, url = {https://doi.org/10.1109/TKDE.2009.79}, author = {Eliseo Clementini and Spiros Skiadopoulos and Roland Billen and Francesco Tarquini} } @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} } @inbook {benou2009a, title = {Encyclopedia of Information Science and Technology, Second Edition}, year = {2009}, pages = {1-7}, publisher = {IGI Global}, organization = {IGI Global}, chapter = {Exploiting Context in Mobile Applications}, abstract = {In the mobile and pervasive computing environment, software engineering should not treat diversity and mobility as problems to overcome, but seek methods of which it could take advantage instead. In these environments, the selection of purpose-oriented and timely information, tailored to user preferences and media characteristics will ensure an optimised information delivery. To this end, the context .the information that surrounds the human-computer interaction. plays a key role and is rapidly changing in mobile settings, and the understanding of it is indispensable for the application designers in order to choose, capture and exploit it. In this work, we present an architecture facilitating the collection of context information and its exploitation for optimized information delivery, within mobile and pervasive computing environments.}, doi = {10.4018/978-1-60566-026-4.ch236}, url = {https://www.igi-global.com/chapter/exploiting-context-mobile-applications/13774}, author = {Poulcheria Benou and Costas Vassilakis}, editor = {Mehdi Khosrow-Pour} } @conference {DBLP:conf/ssdbm/BourosSDSS09, title = {Evaluating Reachability Queries over Path Collections}, booktitle = {Scientific and Statistical Database Management, 21st International Conference, SSDBM 2009, New Orleans, LA, USA, June 2-4, 2009, Proceedings}, year = {2009}, pages = {398{\textendash}416}, doi = {10.1007/978-3-642-02279-1_29}, url = {https://doi.org/10.1007/978-3-642-02279-1_29}, author = {Panagiotis Bouros and Spiros Skiadopoulos and Theodore Dalamagas and Dimitris Sacharidis and Timos K. Sellis} } @conference {562, title = {EverLast: A Distributed Architecture for Preserving the Web}, booktitle = {Proceedings of the Joint Conference on Digital Libraries (JCDL)}, year = {2009}, month = {June}, address = {Austin, Texas}, author = {Avishek Anand and Srikanta Bedathur and Klaus Berberich and Ralf Schenkel and Christos Tryfonopoulos} } @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 {586, title = {Approximate Information Filtering in Peer-to-Peer Networks}, booktitle = {Proceedings of the 9th Web Information Systems Engineering (WISE) Conference}, year = {2008}, month = {September}, address = {Auckland, New Zealand}, author = {Christian Zimmer and Christos Tryfonopoulos and Klaus Berberich and Manolis Koubarakis and Gerhard Weikum} } @article {DBLP:journals/dke/TerrovitisVSBCMR07, title = {Modeling and language support for the management of pattern-bases}, journal = {Data Knowl. Eng.}, volume = {62}, number = {2}, year = {2007}, pages = {368{\textendash}397}, doi = {10.1016/j.datak.2006.10.002}, url = {https://doi.org/10.1016/j.datak.2006.10.002}, author = {Manolis Terrovitis and Panos Vassiliadis and Spiros Skiadopoulos and Elisa Bertino and Barbara Catania and Anna Maddalena and Stefano Rizzi} } @conference {564, title = {Node Behavior Prediction for Large-Scale Approximate Information Filtering}, booktitle = {Proceedings of the International Workshop on Large-Scale Distributed Systems for Information Retrieval (LSDS-IR @ SIGIR)}, year = {2007}, month = {July}, address = {Amsterdam, The Netherlands}, author = {Christian Zimmer and Christos Tryfonopoulos and Klaus Berberich and Gerhard Weikum and Manolis Koubarakis} } @conference {adpuc06-BKTWZ, title = {MAPS: Approximate Publish/Subscribe Functionality in Peer-to-Peer Networks}, booktitle = {Proceedings of Advanced Data Processing in Ubiquitous Computing Workshop (ADPUC @ Middleware)}, year = {2006}, month = {November}, pages = {1{\textendash}6}, address = {Melbourne, Australia}, author = {Klaus Berberich and Manolis Koubarakis and Christos Tryfonopoulos and Gerhard Weikum and Christian Zimmer} } @proceedings {DBLP:conf/edbt/2004, title = {Advances in Database Technology - EDBT 2004, 9th International Conference on Extending Database Technology, Heraklion, Crete, Greece, March 14-18, 2004, Proceedings}, volume = {2992}, year = {2004}, publisher = {Springer}, isbn = {3-540-21200-0}, doi = {10.1007/b95855}, url = {https://doi.org/10.1007/b95855}, editor = {Elisa Bertino and Stavros Christodoulakis and Dimitris Plexousakis and Vassilis Christophides and Manolis Koubarakis and Klemens B{\"o}hm and Elena Ferrari} } @conference {DBLP:conf/ssdbm/TerrovitisVSBCM04, title = {Modeling and Language Support for the Management of Pattern-Bases}, booktitle = {Proceedings of the 16th International Conference on Scientific and Statistical Database Management (SSDBM 2004), 21-23 June 2004, Santorini Island, Greece}, year = {2004}, pages = {265{\textendash}274}, doi = {10.1109/SSDBM.2004.54}, url = {http://doi.ieeecomputersociety.org/10.1109/SSDBM.2004.54}, author = {Manolis Terrovitis and Panos Vassiliadis and Spiros Skiadopoulos and Elisa Bertino and Barbara Catania and Anna Maddalena} } @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 {599, title = {Agents in Decentralised Information Ecosystems: The DIET Approach}, booktitle = {Symposium on Information Agents for E-Commerce, AISB Convention}, year = {2001}, month = {March}, address = {University of York, United Kingdom}, abstract = {The complexity of the current global information infrastructure requires novel means of understanding and exploiting the dynamics of information. One means may be through the concept of an information ecosystem. An information ecosystem is analogous to a natural ecosystem in which there are flows of materials and energy analogous to information flow between many interacting individuals. This paper describes a multi-agent platform, DIET (Decentralised Information Ecosystem Technologies) that can be used to implement open, robust, adaptive and scalable ecosystem-inspired systems. We describe the design principles of the DIET software architecture, and present a simple example application based upon it. We go on to consider how the DIET system can be used to develop information brokering agents, and how these can contribute to the implementation of economic interactions between agents, as well as identifying some open questions relating to research in these areas. In this way we show the capacity of the DIET system to support applications using information agents.}, author = {P. Marrow and Manolis Koubarakis and R.H. van Lengen and F. Valverde-Albacete and E. Bonsma and J. Cid-Suerio and A.R. Figueiras-Vidal and A. Gallardo-Antolin and C. Hoile and T. Koutris and H. Molina-Bulla and A. Navia-Vazquez and Paraskevi Raftopoulou and N. Skarmeas and Christos Tryfonopoulos and F. Wang and C. Xiruhaki} } @conference {aisb01-MKL+, title = {Agents in Decentralised Information Ecosystems: The DIET Approach}, booktitle = {Proccedings of the Symposium on Information Agents for E-Commerce, AISB Convention}, year = {2001}, month = {March}, pages = {109{\textendash}117}, address = {York, UK}, author = {P. Marrow and Manolis Koubarakis and R.H. van Lengen and F. Valverde-Albacete and E. Bonsma and J. Cid-Suerio and A.R. Figueiras-Vidal and A. Gallardo-Antolin and C. Hoile and T. Koutris and H. Molina-Bulla and A. Navia-Vazquez and Paraskevi Raftopoulou and N. Skarmeas and Christos Tryfonopoulos and F. Wang and C. Xiruhaki} } @proceedings {DBLP:conf/caise/2000, title = {Advanced Information Systems Engineering, 12th International Conference CAiSE 2000, Stockholm, Sweden, June 5-9, 2000, Proceedings}, volume = {1789}, year = {2000}, publisher = {Springer}, isbn = {3-540-67630-9}, doi = {10.1007/3-540-45140-4}, url = {https://doi.org/10.1007/3-540-45140-4}, editor = {Benkt Wangler and Lars Bergman} } @proceedings {DBLP:conf/stdbm/1999, title = {Spatio-Temporal Database Management, International Workshop STDBM{\textquoteright}99, Edinburgh, Scotland, September 10-11, 1999, Proceedings}, volume = {1678}, year = {1999}, publisher = {Springer}, isbn = {3-540-66401-7}, doi = {10.1007/3-540-48344-6}, url = {https://doi.org/10.1007/3-540-48344-6}, editor = {Michael H. B{\"o}hlen and Christian S. Jensen and Michel Scholl} } @conference {1993-boukouvalas-hci, title = {An Enhanced System for File Access in a Distributed UNIX Environment}, booktitle = {Proceedings of the 4th Hellenic Conference on Informatics}, year = {1993}, month = {12}, abstract = {In this study we present an Enhanced File System for a Distributed Unix Environment. The Enhanced Unix File System implements a flexible protection mechanism for files and directories. It is based on the concept of Access Control Lists (ACL), which allows different permissions for files and directories to be given to specific users. His work was developed under the SunOS/NFS distributed environment, using Remote Procedure Calls (RPC) to implement the communication between the client and the server. The system consists of a daemon process working as a server and a set of client processes that provide different file and directory services. There may be running many different servers and clients over the same network. The client processes transparently locate the appropriate server for each transaction. The system also provides an open programming environment for the development of new applications. Both the user and the programmer interface of the system are kept close to standard UNIX.}, url = {http://cst.uop.gr/images/papers/1993-kassapidis-hci.pdf}, author = {Boucouvalas, C. and Costas Vassilakis and P. Georgiadis} }