Nikolaos Simou

An ontology infrastructure for multimedia reasoning

In this paper, an ontology infrastucture for multimedia reasoning is presented, making it possible to combine low-level visual descriptors with domain specific knowledge and subsequently analyze multimedia content with a generic algorithm that makes use of this knowledge. More specifically, the ontology infrastructure consists of a domain-specific ontology, a visual descriptor ontology (VDO) and an upper ontology. In order to interpret a scene, a set of atom regions is generated by an initial segmentation and their descriptors are extracted. Considering all descriptors in association with the related prototype instances and relations, a genetic algorithm labels the atom regions. Finally, a constraint reasoning engine enables the final region merging and labelling into meaningful objects.

Storing and Querying Fuzzy Knowledge in the Semantic Web Using FiRE

An important problem for the success of ontology-based applications is how to provide persistent storage and querying. For that purpose, many RDF tools capable of storing and querying over a knowledge base, have been proposed. Recently, fuzzy extensions to ontology languages have gained considerable attention especially due to their ability to handle vague information. In this paper we investigate on the issue of using classical RDF storing systems in order to provide persistent storing and querying over large scale fuzzy information. To accomplish this we propose a novel way for serializing fuzzy information into RDF triples, thus classical storing systems can be used without any extensions. Additionally, we extend the existing query languages of RDF stores in order to support expressive fuzzy querying services over the stored data. All our extensions have been implemented in FiRE—an expressive fuzzy DL reasoner that supports the language fuzzy-\(\mathcal{SHIN}\). Finally, the proposed architecture is evaluated using an industrial application scenario about casting for TV commercials and spots.

Linked European television heritage

The EUscreen project represents the European television archives and acts as a domain aggregator for Europeana, Europes digital library. The main motivation for its creation was to provide unified access to a representative collection of television programs, secondary sources and articles, and in this way to allow students, scholars and the general public to study the history of television in its wider context. In this paper, we present the methodology followed for publishing the EUscreen dataset as Linked Open Data.

Enriching and publishing cultural heritage as linked open data

In the last decade, a lot of effort has been put by the cultural community around the world into digitization and aggregation activities. The main outcome of these was the development of portals like Europeana, DPLA, DigitalNZ, and National Library of Australia, which are collecting and providing access to the public digitized cultural assets from Europe, America, New Zealand, and Australia, respectively. Their main objective, however, is not only to bring the public closer to culture but also to efficiently represent information about cultural objects that will make them useful to various target groups like teachers, students, and developers by also permitting their creative reuse. The best practice for fulfilling this requirement is the publication of such information according to the Linked Open Data (LOD) principles. In this chapter, we present the tools developed and the methodology adopted through the participation of our group in aggregation activities for enriching and publishing cultural heritage as Linked Open Data.

Web Reasoning for Cultural Heritage

Cultural Heritage is the focus of a great and continually increasing number of R&D initiatives, aiming at efficiently managing and disseminating cultural resources on the Web. As more institutions make their collections available online and proceed to aggregate them in domain repositories, knowledge-based management and retrieval becomes a necessary evolution from simple syntactic data exchange. In the process of aggregating heterogeneous resources and publishing them for retrieval and creative reuse, networks such as Europeana and DPLA invest in technologies that achieve semantic data integration. The resulting repositories join the Linked Open Data cloud, allowing to link cultural heritage domain knowledge to existing datasets. Integration of diverse information is achieved through the use of formal ontologies, enabling reasoning services to offer powerful semantic search and navigation mechanisms.

Connectionist Models for Formal Knowledge Adaptation

Both symbolic knowledge representation systems and artificial neural networks play a significant role in Artificial Intelligence. A recent trend in the field aims at interweaving these techniques, in order to improve robustness and performance of classification and clustering systems. In this paper, we present a novel architecture based on the connectionist adaptation of ontological knowledge. The proposed architecture was used effectively to improve image segment classification within a multimedia application scenario.

Linked television heritage

The EUscreen project represents the European television archives, inc. a large number of members from the European Broadcasting Union (EBU), and acts as a domain aggregator for Europeana, Europes digital library. The main proposal from Euscreen has been to provide a harmonised access to a collection of television programmes, and associated resources such as articles. One of the essential declared goals is to allow students, scholars and the general public to study the history of television in its wider context. This paper presents the methodology followed for generating and publishing the EUscreen dataset as Linked Open Data.