@article {818, title = {Disruptive Technologies for Parliaments: A Literature Review}, journal = {Future Internet}, volume = {15}, year = {2023}, month = {feb}, pages = {66}, abstract = {

Exploitation and use of disruptive technologies, such as the Internet of Things, recommender systems, and artificial intelligence, with an ambidextrous balance, are a challenge, nowadays. Users of the technologies, and stakeholders, could be part of a new organisational model that affects business procedures and processes. Additionally, the use of inclusive participatory organisational models is essential for the effective adoption of these technologies. Such models aim to transform organisational structures, as well. Public organisations, such as the parliament, could utilise information systems{\textquoteright} personalisation techniques. As there are a lot of efforts to define the framework, the methodology, the techniques, the platforms, and the suitable models for digital technologies adoption in public organisations, this paper aims to provide a literature review for disruptive technology inclusive use in parliaments. The review emphasises the assessment of the applicability of the technologies, their maturity and usefulness, user acceptance, their performance, and their correlation to the adoption of relevant innovative, inclusive organisational models. It is argued that the efficient digital transformation of democratic institutions, such as parliaments, with the use of advanced e-governance tools and disruptive technologies, requires strategic approaches for adoption, acceptance, and inclusive service adaptation.

}, keywords = {artificial intelligence, digital transformation, inclusiveness, Internet of Things, parliament, Recommender Systems}, doi = {https://doi.org/10.3390/fi15020066}, url = {https://www.mdpi.com/1999-5903/15/2/66}, author = {Dimitris Koryzis and Dionisis Margaris and Costas Vassilakis and Konstantinos Kotis and Dimitris Spiliotopoulos} } @article {798, title = {On the Design of IoT Security: Analysis of Software Vulnerabilities for Smart Grids}, journal = {Energies}, volume = {14}, year = {2021}, month = {may}, pages = {2818}, abstract = {

The 5G communication network will underpin a vast number of new and emerging services, paving the way for unprecedented performance and capabilities in mobile networks. In this setting, the Internet of Things (IoT) will proliferate, and IoT devices will be included in many 5G application contexts, including the Smart Grid. Even though 5G technology has been designed by taking security into account, design provisions may be undermined by software-rooted vulnerabilities in IoT devices that allow threat actors to compromise the devices, demote confidentiality, integrity and availability, and even pose risks for the operation of the power grid critical infrastructures. In this paper, we assess the current state of the vulnerabilities in IoT software utilized in smart grid applications from a source code point of view. To that end, we identified and analyzed open-source software that is used in the power grid and the IoT domain that varies in characteristics and functionality, ranging from operating systems to communication protocols, allowing us to obtain a more complete view of the vulnerability landscape. The results of this study can be used in the domain of software development, to enhance the security of produced software, as well as in the domain of automated software testing, targeting improvements to vulnerability detection mechanisms, especially with a focus on the reduction of false positives.

}, keywords = {Internet of Things, robustness, security, software vulnerabilities}, doi = {10.3390/en14102818}, author = {Christos-Minas Mathas and Costas Vassilakis and Nicholas Kolokotronis and Charilaos C. Zarakovitis and Michail-Alexandros Kourtis} } @mastersthesis {848, title = {Development and evaluation of a team formation algorithm for gaming environments}, year = {2021}, month = {10/2021}, pages = {48}, type = {Undergraduate}, abstract = {

In the context of multiplayer online games, but in many other group activities that entail collaboration between user, appropriate group formation is a critical issue. Groups should be formulated in a way that on the one hand user collaboration (or collaboration avoidance) preferences are respected, and on the other hand collaboration potential and productivity of groups is maximized.


In the current thesis, we consider an internet-based collaboration environment, where users work in pairs and, after their collaboration, each of them rates the quality of work and the quality of collaboration of his/her partner. Moreover, users have the option to express a positive, negative or neutral opinion towards the possibility of cooperating with individual users. For such an environment, we have developed an algorithm that employs linear
programming techniques, in order to create an optimal user pair formulation, considering the ratings that users have assigned to other users and collaboration intention statements. We present in detail the system structure, the algorithms and techniques employed, and we analyze the performance of the system in terms of the time needed to formulate user pair assignments
in various indicative cases. Finally, potential future extensions are outlined.

}, keywords = {glpk, Java, linear programming, maximization problem, scpsolver, User groups, μέθοδος simplex method}, author = {Iasonas Topalidis} } @conference {809, title = {Digital applications for the preservation of historic memory: the case of the Kalamata digital museum (greek title: Ψηφιακές εφαρμογές για τη διατήρηση της ιστορικής μνήμης: Η περίπτωση του ψηφιακού μουσείου Καλαμάτας)}, booktitle = {4th PanHellenic Conference on Digital Cultural Heritage-EuroMed 2021}, year = {2021}, abstract = {

The evolution in technology and informatics have changed all aspects of our lives, including civilization-related ones. And while interdisciplinary research involving the scientific disciplines of human sciences and informatics was underdeveloped for many years, it seems that informatics and technology can constitute the catalyst for the rapid advancement of certain areas in human sciences. This has become more than apparent during the last decade, especially in museums and venues related to civilization, where the application of technology, both for the improvement of the visitors{\textquoteright} experience and for the support of scientists (archaeologists, museologists etc), is now taken as granted. In particular, the measures that have been applied during the last two years of the COVID19 pandemic, further accelerate the developments towards digitalization and switching to an online world. The "Kalamata 1821: roads of freedom" project was the starting point for the creation of the first mixed digital museum in the region of the Peloponnese; this museum is strongly related to the history of Greece, starting from the Revolution of 1821 and its relationship with Kalamata. This paper analyses the process of design, preparation and implementation of digital multimedia applications that are installed on the digital museum infrastructure. The applications have been designed to maximize the information that can be perceived within the limited time frame during of a museum visit, offering in parallel means to obtain some of the information presented and store them on a mobile device.

}, author = {Poulopoulos, Vassileios and Wallace, Manolis and Antoniou, Antzela and Costas Vassilakis and Panagiotidi, Vayia and Zacharias, Nikolaos} } @article {782, title = {Data-Assisted Persona Construction Using Social Media Data}, journal = {Big Data and Cognitive Computing}, volume = {4}, year = {2020}, month = {aug}, pages = {21}, abstract = {

User experience design and subsequent usability evaluation can benefit from knowledge about user interaction, types, deployment settings and situations. Most of the time, the user type and generic requirements are given or can be obtained and used to model interaction during the design phase. The deployment settings and situations can be collected through the needfinding phase, either via user feedback or via the automatic analysis of existing data. Personas may be defined using the aforementioned information through user research analysis or data analysis. This work utilizes an approach to activate an accurate persona definition early in the design cycle, using topic detection to semantically enrich the data that are used to derive the persona details. This work uses Twitter data from a music event to extract information that can be used to assist persona creation. A user study in persona construction compares the topic modelling metadata to a traditional user collected data analysis for persona construction. The results show that the topic information-driven constructed personas are perceived as having better clarity, completeness and credibility. Additionally, the human users feel more attracted and similar to such personas. This work may be used to model personas and recommend suitable ones to designers of other products, such as advertisers, game designers and moviegoers.

}, keywords = {Cultural Events, Persona, personalization, Topic Modelling, Usability, User Experience, User Interface Design}, doi = {10.3390/bdcc4030021}, author = {Dimitris Spiliotopoulos and Dionisis Margaris and Costas Vassilakis} } @article {721, title = {Detection of intermittent faults in software programs through identification of suspicious shared variable access patterns}, journal = {Journal of Systems and Software}, volume = {159}, year = {2020}, month = {30 October 2019}, pages = {110455}, abstract = {Intermittent faults are a very common problem in the software world, while difficult to be debugged. Most of the existing approaches though assume that suitable instrumentation has been provided in the program, typically in the form of assertions that dictate which program states are considered to be erroneous. In this paper we propose a method that can be used to detect probable sources of intermittent faults within a program. Our method proposes certain points in the code, whose data interdependencies combined with their execution interweaving indicate that they could be the cause of intermittent faults. It is the responsibility of the user to accept or reject these proposals. An advantage of this method is that it removes the need for having predefined assertion points in the code, being able to detect potential sources of intermittent faults in the whole bulk of the code, with no instrumentation requirements on the side of the programmer. The proposed approach exploits information from the dynamic behavior of the program. In comparison with parser-based approaches which analyze only the program structure, our approach is immutable to language term changes and in general is not depending on any user-provided assertions or configuration.}, keywords = {Fault detection, Intermittent faults, Model-based checking, Shared variables}, issn = {0164-1212}, doi = {10.1016/j.jss.2019.110455}, author = {Panagiotis Sotiropoulos and Costas Vassilakis} } @conference {spiliotopoulos_2019_asonam, title = {Data-driven Country Safety Monitoring Terrorist Attack Prediction}, booktitle = {Proceedings of the 2019 IEEE/ACM International Conference on Advances in Social Networks Analysis and Mining (ASONAM 2019)}, year = {2019}, month = {aug}, abstract = {Terrorism is a key risk for prospective visitors of tourist desti-nations. This work reports on the analysis of past terrorist at-tack data, focusing on tourist-related attacks and attack types in Mediterranean EU area and the development of algorithms to predict terrorist attack risk levels. Data on attacks in 10 coun-tries have been analyzed to quantify the threat level of tourism-related terrorism based on the data from 2000 to 2017 and for-mulate predictions for subsequent periods. Results show that predictions on potential target types can be derived with ade-quate accuracy. Such results are useful for initiating, shifting and validating active terrorism surveillance based on real pre-dicted attack and target types per country.}, keywords = {Data Analysis, Risk Calculation, Safety Perception, Terrorist Attacks, Threat Ranking}, author = {Dimitris Spiliotopoulos and Costas Vassilakis and Dionisis Margaris} } @conference {545, title = {Data Science Tutor: An online platform for automated exercise solving in Data Science}, booktitle = {Proceedings of the 9th Conference on Computer Science Teaching (DIDINFO)}, year = {2018}, month = {October}, address = {Thessaloniki, Greece}, author = {Christos Tryfonopoulos and Charis Kotsiopoulos and Paraskevi Raftopoulou} } @inbook {DBLP:reference/gis/Skiadopoulos17, title = {Directional Relations}, booktitle = {Encyclopedia of GIS.}, year = {2017}, pages = {476{\textendash}482}, doi = {10.1007/978-3-319-17885-1_1539}, url = {https://doi.org/10.1007/978-3-319-17885-1_1539}, author = {Spiros Skiadopoulos} } @article {582, title = {Distributed Large-Scale Information Filtering}, journal = {Transactions on Large-Scale Data- and Knowledge-Centered Systems (TLDKS)}, volume = {13}, year = {2014}, pages = {91{\textendash}122}, abstract = {We study the problem of distributed resource sharing in peer-to-peer networks and focus on the problem of information filter- ing. In our setting, subscriptions and publications are specified using an expressive attribute-value representation that supports both the Boolean and Vector Space models. We use an extension of the distributed hash table Chord to organise the nodes and store user subscriptions, and utilise efficient publication protocols that keep the network traffic and latency low at filtering time. To verify our approach, we evaluate the proposed protocols experimentally using thousands of nodes, millions of user subscriptions, and two different real-life corpora. We also study three important facets of the load-balancing problem in such a scenario and present a novel algorithm that manages to distribute the load evenly among the nodes. Our results show that the designed protocols are scalable and efficient: they achieve expressive information filtering functionality with low message traffic and latency.}, keywords = {distributed hash tables, Information management, publish/subscribe}, author = {Christos Tryfonopoulos and Stratos Idreos and Manolis Koubarakis and Paraskevi Raftopoulou} } @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 {550, title = {DS4: A Distributed Social and Semantic Search System}, booktitle = {Proceedings of 35th European Conference on Information Retrieval (ECIR)}, year = {2013}, month = {March}, address = {Moscow, Russia}, author = {Dionisis Kontominas and Paraskevi Raftopoulou and Christos Tryfonopoulos and E.G.M. Petrakis} } @conference {539, title = {DS4: Introducing Semantic Friendship in Distributed Social Networks.}, booktitle = {Proceedings of the 21st International Conference on Cooperative Information Systems (CoopIS)}, year = {2013}, month = {September}, address = {Graz, Austria}, author = {Paraskevi Raftopoulou and Christos Tryfonopoulos and E.G.M. Petrakis and Nikos Zevlis} } @article {Giannikopoulos2011, title = {A distributed recommender system architecture}, journal = {International Journal of Web Engineering and Technology}, volume = {7}, number = {3}, year = {2012}, pages = {203{\textendash}227}, abstract = {In contemporary internet architectures, including server farms and blog aggregators, web log data may be scattered among multiple cooperating peers. In order to perform content personalization through provision of recommendations on such architectures, it is necessary to employ a recommendation algorithm; however the majority of such algorithms are centralized, necessitating excessive data transfers and exhibiting performance issues when the number of users or the volume of data increase. In this paper we propose an approach where the clickstream information is distributed to a number of peers, which cooperate for discovering frequent patterns and for generating recommendations, introducing (a) architectures that allow the distribution of both the content and the clickstream database to the participating peers and (b) algorithms that allow collaborative decisions on the recommendations to the users, in the presence of scattered log information. The proposed approach may be employed in various domains, including digital libraries, social data, server farms and content distribution networks.}, doi = {10.1504/IJWET.2012.048517}, author = {Giannikopoulos, P. and Costas Vassilakis} } @conference {daradim2008, title = {A Drupal CMS Module for Managing Museum Collections}, booktitle = {International Symposium on Information \& communication technologies in cultural heritage}, year = {2008}, month = {10}, abstract = {Digitization efforts and web presentations are currently on-going in many museums, archives, libraries and culture heritage institutions in general, exploiting the advent of WWW and digitization technologies. The main benefits from these efforts are exhibit cataloguing, their effective management, preservation and showcasing, and their presentation to the public through the WWW. However, many museums, especially the smaller ones, cannot afford a commercial product and resort to using simple static web pages for their web presence and exhibit presentation. Content Management Systems (CMS), especially open-source ones which come with practically zero-cost, are more and more frequently adopted by museums to create and maintain their website, since they simplify the creation and editing of the web pages and may be used by non-computer experts. In this work we present a module for the Drupal CMS, which provides functionality for (a) Database schema extension to accommodate museum exhibit and collection information (b) Digital exhibit representation (DER) management. (c) Provision of administration pages through which the museum personnel may enter and manage exhibit and collection information (d) WWW scowcasing and (e) Batch data import/export, to facilitate information exchange with other museums.}, author = {I. Daradimos and Costas Vassilakis and Akrivi Katifori} } @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} } @conference {597, title = {Design and Evaluation of Semantic Similarity Measures for Concepts Stemming from the Same or Different Ontologies}, booktitle = {Proceedings of the 4th Workshop on Multimedia Semantics (WMS)}, year = {2006}, month = {June}, address = {Chania, Crete, Greece}, abstract = {Semantic Similarity relates to computing the similarity between concepts (terms) which are not necessarily lexically similar. We investigate approaches to computing semantic similarity by mapping terms to an ontology and by examining their relationships in that ontology. More specifically, we investigate approaches to computing the semantic similarity between natural language terms (using WordNet as the underlying reference ontology) and between medical terms (using the MeSH ontology of medical and biomedical terms). The most popular semantic similarity methods are implemented and evaluated using WordNet and MeSH. The focus of this work is also on cross ontology methods which are capable of computing the semantic similarity between terms stemming from different ontologies (WordNet and MeSH in this work). This is a far more difficult problem (than the single ontology one referred to above) which has not been investigated adequately in the literature. X-Similarity, a novel cross-ontology similarity method is also a contribution of this work. All methods examined in this work are integrated into a semantic similarity system which is accessible on the Web.}, author = {E.G.M. Petrakis and Giannis Varelas and Angelos Hliaoutakis and Paraskevi Raftopoulou} } @conference {559, title = {Distributed Evaluation of Continuous Equi-join Queries over Large Structured Overlay Networks}, booktitle = {Proceedings of the 22nd International Conference on Data Engineering (ICDE)}, year = {2006}, month = {April}, address = {Atlanda, USA}, author = {Stratos Idreos and Christos Tryfonopoulos and Manolis Koubarakis} } @proceedings {DBLP:conf/dawak/2005, title = {Data Warehousing and Knowledge Discovery, 7th International Conference, DaWaK 2005, Copenhagen, Denmark, August 22-26, 2005, Proceedings}, volume = {3589}, year = {2005}, publisher = {Springer}, isbn = {3-540-28558-X}, doi = {10.1007/11546849}, url = {https://doi.org/10.1007/11546849}, editor = {A Min Tjoa and Juan Trujillo} } @conference {571, title = {Distributed Resource Sharing using Self-Organized Peer-to-Peer Networks and Languages from Information Retrieval}, booktitle = {Proceedings of the International Workshop on Self-* Properties in Complex Information Systems (Self-*)}, year = {2004}, month = {May}, address = {Bertinoro, Italy}, author = {Christos Tryfonopoulos and Manolis Koubarakis} } @proceedings {DBLP:conf/dawak/2003, title = {Data Warehousing and Knowledge Discovery, 5th International Conference, DaWaK 2003, Prague, Czech Republic, September 3-5,2003, Proceedings}, volume = {2737}, year = {2003}, publisher = {Springer}, isbn = {3-540-40807-X}, doi = {10.1007/b11825}, url = {https://doi.org/10.1007/b11825}, editor = {Yahiko Kambayashi and Mukesh K. Mohania and Wolfram W{\"o}{\ss}} } @proceedings {DBLP:conf/dolap/2003, title = {DOLAP 2003, ACM Sixth International Workshop on Data Warehousing and OLAP, New Orleans, Louisiana, USA, November 7, 2003, Proceedings}, year = {2003}, publisher = {ACM}, editor = {Stefano Rizzi and Il-Yeol Song} } @conference {536, title = {Data Models and Languages for Agent-Based Textual Information Dissemination}, booktitle = {Proceedings of the 6th International Workshop on Cooperative Information Agents (CIA)}, year = {2002}, month = {September}, publisher = {Springer}, organization = {Springer}, address = {Madrid, Spain}, author = {Manolis Koubarakis and Christos Tryfonopoulos and Paraskevi Raftopoulou and Theodoros Koutris} } @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} } @proceedings {DBLP:conf/dolap/2002, title = {DOLAP 2002, ACM Fifth International Workshop on Data Warehousing and OLAP, November 8, 2002, McLean, VA, USA, Proceedings}, year = {2002}, publisher = {ACM}, isbn = {1-58113-590-4}, editor = {Il-Yeol Song and Dimitri Theodoratos} } @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 {797082, title = {Distributed Information Systems Tailorability: A Component Approach}, booktitle = {FTDCS {\textquoteright}99: Proceedings of the 7th IEEE Workshop on Future Trends of Distributed Computing Systems}, year = {1999}, month = {12}, pages = {95}, publisher = {IEEE Computer Society}, organization = {IEEE Computer Society}, address = {Washington, DC, USA}, abstract = {Distributed software systems need to evolve according to the ever-changing requirements on which they were built. Software systems{\textquoteright} tailorability can be achieved in terms of component software. Atoms and molecules the basic constructs of the ATOMA framework are the building blocks for distributed tailorable component-based software systems. These constructs can be considered as independent agents, that communicate in terms of unanticipated, connections that are established at runtime, thus forming agent communities. System tailorability can take place at two levels. In high level tailorability whole parts of the functionality of a system, represented as agents, can be altered in order to provide new functionality. At a lower level, the tailorability of an agent itself that is the tailorability of its functionality, is achieved through a flexible service mapping implementation for rule-based method invocation.}, isbn = {0-7695-0468-X}, doi = {10.1109/FTDCS.1999.818790}, author = {Dimitrios Theotokis and Kapos, G. D. and Costas Vassilakis and Anya Sotiropoulou and Gyftodimos, G.} }