@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}
}
@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 {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 {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 {Katifori10a,
	title = {Ontologies and the brain: Using spreading activation through ontologies to support personal interaction},
	journal = {Cognitive Systems Research},
	volume = {Volume 11, Issue 1},
	year = {2010},
	note = {cited By (since 1996) 0; Article in Press},
	pages = {25-41},
	abstract = {Ontologies, as knowledge engineering tools, allow information to be modelled in ways resembling to those used by the human brain, and may be very useful in the context of personal information management (PIM) and task information management (TIM). This work proposes the use of ontologies as a long-term knowledge store for PIM-related information, and the use of spreading activation over ontologies in order to provide context inference to tools that support TIM. Details on the ontology creation and content are provided, along with a full description of the spreading activation algorithm and its preliminary evaluation. Β{\textcopyright} 2009 Elsevier B.V.},
	doi = {10.1016/j.cogsys.2009.02.001},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-62249112875\&partnerID=40\&md5=7d25fb986738b4c71a627b3fec24c58d},
	author = {Akrivi Katifori and Costas Vassilakis and Alan Dix}
}
@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 {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}
}
@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}
}
@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 {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}
}
@conference {katifori2008e,
	title = {Ontologies as Tools for Historians},
	booktitle = {International Symposium on Information \& communication technologies in cultural heritage},
	year = {2008},
	month = {10},
	abstract = {Ontologies have been proven invaluable tools in areas like the semantic web and personal information management. There have been many research efforts to create ontologies and supporting tools for Natural Sciences and Biology in particular (e.g. the GO (http://www.geneontology.org/) ontology and supporting tools). However, the domain of History, the science of studying, recording and organizing the knowledge of the past, has yet to benefit from adopting ontologies. In this work, we present our findings in this area, focusing on the aspects of ontology modeling and ontology visualization.},
	author = {Akrivi Katifori and Costas Vassilakis}
}
@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 {Katifori200832,
	title = {Supporting research in historical archives: Historical information visualization and modeling requirements},
	booktitle = {Proceedings of the International Conference on Information Visualisation},
	year = {2008},
	note = {cited By (since 1996) 0},
	month = {7},
	pages = {32-37},
	abstract = {The on-going progress in the area of digital libraries has lead to the beginning of a digitization effort in Historical Archives, as well. The requirements of historical research, which works with histories of entities and incomplete information, create the need for supplementary tools to support users in handling the digitized content. This work is based on a user study of historian information retrieval methods in order to create a set of tools for the context of historical archives, which will facilitate historical data storage, management and visualization. Β{\textcopyright} 2008 IEEE.},
	keywords = {Data visualization, Digital libraries, Heuristics, Historical archive, Information analysis, Information management, Information retrieval, Information science, Information services, Information systems, International conferences, Libraries, Ontology, Search engines, Visualization},
	doi = {10.1109/IV.2008.70},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-51749114860\&partnerID=40\&md5=a5b3e7f74314d5651816424c11e6cbc1},
	author = {Akrivi Katifori and Elena Torou and Costas Vassilakis and C. Halatsis}
}
@conference {katifori2008b,
	title = {Using Spreading Activation through Ontologies to Support Personal Information Management},
	booktitle = {Proceedings of CSKGOI, within IUI 2008},
	year = {2008},
	month = {1},
	abstract = {Recent research in the domain of Personal Information Management has recognized the need for a paradigm shift towards a more activity-oriented system. Ontologies, as semantic networks with a structure not dissimilar to the one used by the human brain for storing long-term knowledge, may be very useful as the basis of such a system. This work proposes the use of spreading activation over ontologies in order to provide to a task-based system and its associated tools with methods to record semantics related to documents and tasks and to support user context inference.},
	url = {http://ceur-ws.org/Vol-323/paper05.pdf},
	author = {Akrivi Katifori and Costas Vassilakis and Alan Dix}
}
@conference {Daradimos2008141,
	title = {WhereRU: GPS position reporting and a personal ontology as a virtual community utility},
	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 = {141-146},
	abstract = {The recent progress of the World Wide Web has created new needs for information sharing in virtual communities. WhereRU is a multiuser GPS position reporting system that allows users to make their location publicly available as well as associate it with information on places, persons and events that may later also serve as reminders of the their experiences when traveling.},
	keywords = {Communication, Global positioning system, Gps positions, Information science, Information sharing, Internet, Multiuser, Ontology, Personal ontologies, Position reporting, Recent progresses, Reporting systems, Satellite navigation aids, Virtual communities, Virtual reality, Web community, World Wide Web},
	doi = {10.1109/RCIS.2008.4632102},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-57349094004\&partnerID=40\&md5=4eaed4757acf5c4da8b292275b92a73a},
	author = {I. Daradimos and Akrivi Katifori and Costas Vassilakis}
}
@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}
}
@conference {Golemati200793,
	title = {Evaluating the significance of the windows explorer visualization in personal information management browsing tasks},
	booktitle = {Proceedings of the International Conference on Information Visualisation},
	year = {2007},
	note = {cited By (since 1996) 0},
	month = {7},
	pages = {93-98},
	abstract = {The visualization of hierarchies is very important for digital information management and presentation systems. Especially in the context of Personal Information Management, file browsers play a very important role. Currently the most common file browser visualizations are Windows Explorer and the simple zoomable visualization offered by Microsoft Windows. This work explores the issue of file browser visualization through a user study based on inter-views and an experiment. Β{\textcopyright} 2007 IEEE.},
	keywords = {Data reduction, File browser visualization, Hierarchical systems, Indented list visualization, Information analysis, User study, Web browsers, Windows explorer},
	doi = {10.1109/IV.2007.46},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-35348919670\&partnerID=40\&md5=f35f306d4063ee2e91e3c573f4ed5d8a},
	author = {M. Golemati and Akrivi Katifori and E.G. Giannopoulou and I. Daradimos and Costas Vassilakis}
}
@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 {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}
}
@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}
}
@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}
}
@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}
}
@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 {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}
}
@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 {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}
}
