Using Spreading Activation through Ontologies to Support Personal Information Management (2009)
Akrivi Katifori, Costas Vassilakis, Alan Dix
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...
An Object-Oriented Approach for Designing Administrative e-Forms and Transactional e-Services (2008)
Dimitris Gouscos, Stathis Rouvas, Costas Vassilakis, Panagiotis Georgiadis
Abstract. Although electronic transaction services are considered to be a necessity for e-government, it has not been possible insofar to unleash their full potential. E-forms are central to the...
FUNCTION ORIENTED HISTORY REPRESENTATION IN DATABASES (2008)
Lázsló Kovács, Costas Vassilakis, L. Kovács, C. Vassilakis
Abstract. In the past years the management of temporal data has attracted numerous researchers resulting to a large number of temporal data extensions to the relational and object oriented data...
Domain Expert User Development: The SmartGov Approach (2008)
George Lepouras, Costas Vassilakis, Constantin Halatsis, Panagiotis Georgiadis
In a recent special issue of CACM [1] the approach of end-user development was presented and a number of articles tried to capture the benefits inherent in this approach and the broad range of issues...
A Flexible Framework for Managing Temporal Clinical Trial Data (2008)
Michael Souillard, Carine Souveyet, Costas Vassilakis, Anya Sotiropoulou, Centre Recherche Informatique, Matra Systemes
Abstract – Clinical trials are processes that produce large volumes of complex data, with inherent temporal requirements, since the state of patients evolves during the trials, and the data...
Controlled Caching of Dynamic WWW Pages (2008)
Costas Vassilakis, Giorgos Lepouras
Abstract. In order to increase flexibility and provide up-to-date information, more and more web sites use dynamic content. This practice, however, increases server load dramatically, since each...
Tailorability in the context of E-government Information Systems: An approach (2008)
George Lepouras, Anya Sotiropoulou, Dimitrios Theotokis, Costas Vassilakis
The ever changing environment information systems model, and in particular egovernment ones, intensifies the need for systems that are able to easily, efficiently and transparently adapt to changing...
ADAPTIVE VIRTUAL REALITY SHOPPING MALLS (2008)
George Lepouras, Costas Vassilakis
Firms and organizations are increasingly exploiting electronic channels to reach their customers and create new business opportunities. To this end, electronic shops have been developed, either...
George Lepouras, Costas Vassilakis
gw @ cis.strath.ac.uk
A Blackboard-oriented Architecture for e-Government service composition (2008)
Costas Vassilakis, Anya Sotiropoulou, Dimitrios Theotokis, Dimitris Gouscos
A requirement for electronic government initiatives to succeed is the ability to offer a citizen-centric view of the government model. The most widely adopted paradigm supporting this task is the...
Barriers To Electronic Service Development (2008)
Costas Vassilakis, George Lepouras, John Fraser, Simon Haston
Abstract. E-government initiatives have been proven to deliver significant benefits, both for suppliers of electronic services (public authorities and organisations) and for the public, to whom...
ADAPTIVE VIRTUAL REALITY MUSEUMS ON THE WEB (2008)
George Lepouras, Costas Vassilakis
This chapter presents an architecture for supporting the creation of adaptive virtual reality museums on the web. It argues whether the task of developing adaptive virtual reality museums is a...
REVERSE ENGINEERING ELECTRONIC SERVICES From e-Forms to Knowledge (2008)
Costas Vassilakis, George Lepouras, Akrivi Katifori
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,...
A Web Browser for ISDN Card Phones (2008)
Dimitris Maroulis, Sotiris Aronis, Vassiliki Nassiopoulou, Nikos Grammenos, Costas Vassilakis
In order to cover the ever-increasing need for more direct and easy access to information, new information access means need to be devised or existing ones need to be further exploited. In this...
A SEMANTICS-BASED CONSULTATIONS WORKBENCH (2008)
Costas Vassilakis, Dimitris Gouscos, Panagiotis Georgiadis
Abstract: eConsultations constitute an effective means to inclusive and informed participation of citizens and society in policy, decision and law formation processes, and an answer to the democratic...
A Flexible Framework for Managing Temporal Clinical Trial Data (2008)
Michael Souillard, Carine Souveyet, Costas Vassilakis, Anya Sotiropoulou
Abstract. Clinical trials are processes that produce large volumes of complex data, with inherent temporal requirements, since the state of patients evolves during the trials, and the data...
An XML model for electronic services (2008)
Costas Vassilakis, George Lepouras, Constantin Halatsis, Tomas Pariente Lobo
Abstract. With the need for electronic services to be developed and deployed more and more rapidly, it is imperative that concrete models of electronic services are developed, to facilitate...
An Active Ontology-based Blackboard Architecture for Web Service (2008)
George Lepouras, Costas Vassilakis, Anya Sotiropoulou, Dimitrios Theotokis, Akrivi Katifori
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...
An Ontology for e-Government Public Services (2008)
Costas Vassilakis, George Lepouras
In the past few years, information and communication technologies are increasingly used for provision of public services, improvement of managerial effectiveness and promotion of democracy, a...
Implementing Embedded Valid Time Query Languages (2008)
Costas Vassilakis, Panagiotis Georgiadis, Timos Sellis
Abstract. Application development on top of database systems is heavily based on the existence of embedded and 4GL languages. However, the issue of designing and implementing embedded or 4GL temporal...
TAILORABLE E-GOVERNMENT INFORMATION SYSTEMS (2008)
George Lepouras, Anya Sotiropoulou, Dimitrios Theotokis, Costas Vassilakis
Real-world information, knowledge and procedures after which information systems are modelled are generally of dynamic nature and subject to changes, due to the emergence of new requirements or...
PARALLEL OPTIMISATION OF JOIN QUERIES USING A TECHNIQUE OF EXHAUSTIVE NATURE 1 (2008)
Maria Spiliopoulou, Michalis Hatzopoulos, Costas Vassilakis
Abstract. In this study we present a technique for the parallel optimisation of join queries that uses the offered coarse-grain parallelism of the underlying architecture in order to reduce the...
An Active Ontology-based Blackboard Architecture for Web Service (2008)
George Lepouras, Costas Vassilakis, Anya Sotiropoulou, Dimitrios Theotokis, Akrivi Katifori
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...
A Flexible Framework for Managing Temporal Clinical Trial Data (2008)
Michael Souillard, Carine Souveyet, Costas Vassilakis, Anya Sotiropoulou
Abstract. Clinical trials are processes that produce large volumes of complex data, with inherent temporal requirements, since the state of patients evolves during the trials, and the data...
Abstract Facilitating VR Museums Web Presence (2008)
George Lepouras, Akrivi Katifori, Costas Vassilakis, Anna Charissi
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 and images. The system is extendable to...
Controlled Caching of Dynamic WWW Pages (2008)
Costas Vassilakis, Giorgos Lepouras
Abstract. In order to increase flexibility and provide up-to-date information, more and more web sites use dynamic content. This practice, however, increases server load dramatically, since each...
Exploiting Form Semantics and Validation Checks to Improve e-Form Layout (2008)
Costas Vassilakis, George Lepouras, Stathis Rouvas, Panagiotis Georgiadis
Abstract. On their route to the electronic era, organisations, release on the web more and more complex form-based services, which require users to enter numerous data items interrelated by business...
COMPUTER GRAPHICS- Methodology and Techniques – Interaction Techniques General Terms: design (2008)
Akrivi Katifori, Constantin Halatsis, George Lepouras, Costas Vassilakis, Eugenia Giannopoulou
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...
REUSABILITY IN ELECTRONIC SERVICES DEVELOPMENT (2008)
Electronic government employs electronic services to facilitate interaction with citizens and enterprises and deliver a rich and high quality spectrum of services. Development of electronic services...
Web Service Execution Streamlining (2008)
Costas Vassilakis, George Lepouras, Akrivi Katifori
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...
FUNCTION ORIENTED HISTORY REPRESENTATION IN DATABASES (2007)
Lazslo Kovac, Costas Vassilakis
Abstract. In the past years the management of temporal data has attracted numerous researchers resulting to a large number of temporal data extensions to the relational and object oriented data...
Implementing Embedded Valid Time Query Languages (2007)
Costas Vassilakis, Panagiotis Georgiadis, Timos Sellis
Abstract. Application development on top of database systems is heavily based on the existence of embedded and 4GL languages. However, the issue of designing and implementing embedded or 4GL temporal...
e-Citizens and e-Consumers: Is There a Difference? (2007)
Dimitris Dadiotis, Dimitris Kalles, Eirini Ntoutsi, Athanassios Papagelis Ahead, George Laskaridis, Costas Vassilakis, ...
Workshop Proceedings of the 1 st Panhellenic Conference with international participation in Human Computer Interaction (PC-HCI 2001),
Creating an Ontology for the User Profile: Method and Applications (2007)
Maria Golemati, Akrivi Katifori, Costas Vassilakis, George Lepouras, Constantin Halatsis
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...
Barriers to Electronic Service Development (2006)
Vassilakis, Costas., Lepouras, George., Fraser, John., Haston, Simon., Georgiadis, Panagiotis.
e-Service Journal - Volume 4, Number 1, Fall 2005
Integrating E-Government Public Transactional Services Into Public Authority Workflows (2004)
Costas Vassilakis, George Lepouras, Stathis Rouvas, Panagiotis Georgiadis
Documents submitted by citizens through electronic services, deployed in the context of e-government, must usually undergo processing by some organisational information system in order to complete...
Virtual museums for all: Employing game technology for edutainment (2004)
George Lepouras, Costas Vassilakis
Abstract. Museums have started to realise the potential of new technologies for the development of edutainment content and services for their visitors. Virtual reality technologies promise to offer a...
Virtual museums for all: Employing game technology for edutainment (2004)
George Lepouras, Costas Vassilakis
Abstract. Museums have started to realise the potential of new technologies for the development of edutainment content and services for their visitors. Virtual reality technologies promise to offer a...
A Framework Formanaging the Lifecycle of Transactional E-Government Services (2003)
Costas Vassilakis, C. Vassilakis, George Laskaridis, Stathis Rouvas, Panagiotis Georgiadis, George Lepouras, ...
Fillin an submission of electron` forms is a key issue fore-governI`@7 sino most electronE services o#eredin thisconRQ@ inRQ@ somevarian ofelectron` forms.Inms.R: IT experts are placedin thecenQ+...
Serving enhanced hypermedia information (2002)
George Lepouras, Costas Vassilakis
gw @ cis.strath.ac.uk Abstract. An apparent limitation of existing Web pages is their inability to accommodate differences in the interests and needs of individual users. The present paper describes...
Transactional e-Government Services: an Integrated Approach (2002)
Costas Vassilakis, C. Vassilakis, George Laskaridis, Stathis Rouvas, Panagiotis Georgiadis, George Lepouras, ...
Although form-based services are fundamental to e-government activities, their widespread does neither meet the citizen's expectations, nor the offered technological potential. The main reason...
An Object-Oriented Approach for Designing Administrative E-Forms and Transactional E-Services (2002)
Transactional E-services, Dimitris Gouscos, Stathis Rouvas, Costas Vassilakis, Panagiotis Georgiadis
E-forms are central to the development of e-government, being a basic means for implementing most of the public services considered as required for local and central public administration...
Building a VR-Museum in a Museum (2001)
George Lepouras, Dimitrios Charitos, Costas Vassilakis, Anna Charissi, Leda Halatsi
Abstract: Past years have seen the exploitation of multimedia techniques and lately the introduction of virtual reality methods to create new forms of presentation for museums ' exhibitions....
e-Citizens and eConsumers: Is There a Difference (2001)
George Laskaridis, Costas Vassilakis, George Lepouras, Stathis Rouvas
Both the business sector and the government are nowadays embracing Internet technologies in order to provide high quality on-line services to their “target groups”. In both cases, service...
Building a VR-Museum in a Museum (2001)
George Lepouras, Dimitrios Charitos, Costas Vassilakis, Anna Charissi, Leda Halatsi
Abstract: Past years have seen the exploitation of multimedia techniques and lately the introduction of virtual reality methods to create new forms of presentation for museums ' exhibitions....
An Optimisation Scheme for Coalesce/Valid Time Selection Operator Sequences (2000)
Abstract: Queries in temporal databases often employ the coalesce operator, either to coalesce results of projections, or data which are not coalesced upon storage. Therefore, the performance and the...
Implementation of Transaction and Concurrency Control Support in a Temporal DBMS (1998)
Costas Vassilakis, Nikos Lorentzos, Panagiotis Georgiadis
Abstract æ Transactions and concurrency control are significant features in database systems, facilitating functions both at user and system level. However, the support of these features in a...
Implementation of Transaction and Concurrency Control Support in a Temporal DBMS (1998)
Costas Vassilakis, Nikos Lorentzos, Panagiotis Georgiadis
Abstract ⎯ Transactions and concurrency control are significant features in database systems, facilitating functions both at user and system level. However, the support of these features in a...
Sotiropoulou: A comparative study of temporal DBMS architectures (1996)
Costas Vassilakis, Panagiotis Georgiadis, Anna Sotiropoulou
Abstract: In the past years, a number of implementations of temporal DBMSs has been reported. Most of these implementations share a common feature, which is that they have been built as an extension...
Sotiropoulou: A comparative study of temporal DBMS architectures (1996)
Costas Vassilakis, Panagiotis Georgiadis, Anna Sotiropoulou
Abstract: In the past years, a number of implementations of temporal DBMSs has been reported. Most of these implementations share a common feature, which is that they have been built as an extension...
Myra Spiliopoulou, Michalis Hatzopoulos, Costas Vassilakis
We propose a model for the estimation of query execution time in an environment supporting bushy and pipelined parallelism. We consider a parallel architecture of processors having private main...
Using parallelism and pipeline for the optimisation of join queries (1992)
Maria Spiliopoulou, Michalis Hatzopoulos, Costas Vassilakis
Abstract: In this study we present a technique for the parallel optimisation of join queries, that uses the offered coarse-grain parallelism of the underlying architecture in order to reduce the...