Ioannis Chrysakis

Foundation for Research and Technology - Hellas | forth · Information Systems Laboratory (ISL)

Ambient Intelligence is an emerging discipline that requires the integration of expertise from a multitude of scientific fields. The role of Artificial Intelligence is crucial not only for bringing intelligence to everyday environments, but also for providing the means for the different disciplines to collaborate. In this paper we describe the desi...

When dealing with dynamically evolving datasets, users are often interested in the state of affairs on previous versions of the dataset, and would like to execute queries on such previous versions, as well as queries that compare the state of affairs across different versions. This is especially true for datasets stored in the Web, where the interl...

The dynamic nature of Web data gives rise to a multitude of problems related to the description and analysis of the evolution of RDF datasets, which are important to a large number of users and domains, such as, the curators of biological information where changes are constant and interrelated. In this paper, we propose a framework that enables ide...

In an increasingly instrumented and inter-connected digital world, citizens generate vast amounts of data, much of it being valuable and a significant part of it being personal. However, controlling who can collect it, limiting what they can do with it, and determining how best to protect it, remain deeply undecided issues. This paper proposes CAPr...

Digital applications typically describe their privacy policy in lengthy and vague documents (called PrPs), but these are rarely read by users, who remain unaware of privacy risks associated with the use of these digital applications. Thus, users need to become more aware of digital applications’ policies and, thus, more confident about their choice...

In this paper, we present an architecture for mobility data spaces enabling trustworthy and reliable data operations along with its main constituent parts. The architecture makes use of a data lake for scalable storage of diverse mobility data sets, on top of which separate computing and storage layers are implemented to allow independent scaling w...

The wine industry has evolved thanks to the introduction of digital technologies in every aspect of the wine production chain and the emerging need of the food industry for qualitative, sustainable, and safe products. As a result, the incorporation of digital services that facilitate access to related data of wine products is crucial for wine enter...

The wine industry has evolved thanks to the introduction of digital technologies in every aspect of the wine production chain and the emerging need of the food industry for qualitative, sustainable, and safe products. As a result, the incorporation of digital services that facilitate access to related data of wine products is crucial for wine enter...

The wine industry has evolved thanks to the introduction of new technologies (e.g., sensors, digital tools). Since the competition in the wine sector is extremely high, transparency via digital means is one of the methods that wine enterprises employ to increase their competitiveness, customer loyalty, and market share. The MiB system, developed in...

CAP-A is offering socio-technical tools to promote collective awareness and informed consent, whereby data collection and use by digital products are driven by the expectations and needs of the consumers themselves.

Consumers are largely unaware regarding the use being made to the data that they generate through smart devices, or their GDPR-compliance, since such information is typically hidden behind vague privacy policy documents, which are often lengthy, difficult to read (containing legal terms and definitions) and frequently changing. This paper describes...

The utilisation of personal data by mobile apps is often hidden behind vague Privacy Policy documents, which are typically lengthy, difficult to read (containing legal terms and definitions) and frequently changing. This paper discusses a suite of tools developed in the context of the CAP-A project, aiming to harness the collective power of users t...

Rewarding people is common in several contexts, such as human resource management and crowdsourcing applications. However, designing a reward strategy is not straightforward, as it requires considering different parameters. These parameters include, for example, management of rewarding tasks and identifying critical features, such as the type of re...

Rewarding people is common in several contexts, such as human resource management and crowdsourcing applications. However, designing a reward strategy is not straightforward, as it requires considering different parameters. These parameters include, for example, management of rewarding tasks and identifying critical features, such as the type of re...

Invited poster, presented in the Researchers Night 2018 which took place in the premises of FORTH.

The CAPrice initiative brings to the fore the creativity of the community towards privacy via specific co-creation tools (structured debates, annotation tools, reward mechanisms and others). Our objective is to improve citizen awareness on privacy issues, and leverage this awareness to motivate the market to adopt more privacy-friendly practices.

Publication management systems can be instrumental in disseminating research results across academia and industry, by providing facilities for uploading, editing and searching for publications. Usually, these systems can be used by individuals to assist them in their research or by organizations to help them classify and promote their publication i...

The concept of the digital business model can bring new capabilities to customers and the desired defending value for OEMs. Some of the digital services that can be encapsulated in cars may include insurance services according to driving style, travel suggestions, infotainment, monitoring car diagnostics, driver health services etc. The autonomous...

D2V, a research prototype for analysing the dynamics of Linked Open Data, has been used to study the evolution of biomedical datasets, such as the Experimental Factor Ontology (EFO) and the Gene Ontology (GO). Datasets are continuously evolving over time as our knowledge increases. Biomedical datasets in particular have undergone rapid changes in r...

This deliverable reports on the summative evaluation of the IdeaGarden System and its components. It provides an account of the aims and methods, the main results, and a synthesis of insights and recommendations for the further advancement of creativity support tools. The evaluation report covers both a summative assessment of the first version of...

The dynamic nature of Web data gives rise to the need of understanding and analyzing the dynamics of individual datasets. As a matter of fact, the value of a dynamic dataset lies not only in its content, but also in its evolution history, which in some applications (e.g., trend analysis and identification), is more important than the data itself. I...

The dynamic nature of Web data gives rise to a multitude of problems related to the identification, computation and management of the evolving versions and the related changes. In this paper, we consider the problem of change recognition in RDF datasets, i.e., the problem of identifying, and when possible give semantics to, the changes that led fro...

The dynamic nature of Web data gives rise to a multitude of problems related to the description and analysis of the evolution of RDF datasets, which are important to a large number of users and domains, such as, the curators of biological information where changes are constant and interrelated. In this paper, we propose a framework that enables ide...

The advances in 3D digitizing technology have found significant application in the Cultural Heritage domain. The systematic large-scale production of digital cultural objects, the diversity of the processes involved and the complexity of describing historical relationships among them imposes the need for innovative knowledge management to handle al...

This paper presents the development of a new Web based LiDAR (Light Detection And Ranging) 3D point cloud viewer addressing mobility and portability issues arising from remote field applications by numerous multidisciplinary collaborative scientists. This new Web Browser-based 3D point cloud viewer, hereafter called 3DSYSTEK viewer, was developed a...

The diversity of contemporary technology on 3D-model digitizing and processing procedures necessitates the systematic documentation of all the involved activities. In this paper we present essential concepts and the infrastructure of 3D-SYSTEK (3DS), a system that supports the 3D-modelling provenance preservation in the Cultural Heritage (CH) domai...

Terrestrial laser scanning is a new fast developing technology that allows for the recording and visualisation of the 3D geometry of monuments. The problem lies on the various types of hardware equipment and software systems used in the whole workflow of the 3D scanning process. These often results in a large volume of interim and final products wi...

This research investigates the application of new system for 3D documentation of land degradation and its effect [1,2] on areas of cultural heritage via complete 3D data acquisition, 3D modeling and metadata recording using terrestrial laser scanners (TLS) [3,4,5]. As land degradation progresses through time it is important to be able to map and ex...

In p2p networks, top-k query processing can provide a lot of advantages both in time and bandwidth consumption. Several algorithms have been proposed for the evaluation of top-k queries. A large percentage of them follow the Threshold Approach. We focus on the main adaptations of threshold algorithms fulfilling the requirements of modern p2p applic...

Requirements for widely distributed information systems supporting virtual organizations have given rise to a new category of peer-to-peer (p2p) systems called schema-based. In such systems each peer is a database management system in itself, exposing its own schema. In such a setting, a main objective is the efficient search across peer databases...

COMPUTER SCIENCE DEPARTMENT, UNIVERSITY OF CRETE The idea of Peer-to-peer (P2P) computing offers new opportunities for building highly distributed data systems. The advent of Semantic Web gave rise to a new category of peer-topeer systems called Schema-Based. In Schema-Based P2P systems each peer is a whole database management system in itself. Eac...

Ranking queries, also known as top-k queries, have drawn considerable attention due to their usability in various applications. Several algorithms have been proposed for the evaluation of top-k queries. A large percentage of them follow the Threshold Approach. In p2p networks, top-k query processing can provide a lot of advantages both in time and...