Rapid growth of documents, web pages, and other types of text content is a huge challenge for the modern content management systems. One of the problems in the areas of information storage and retrieval is the lacking of semantic data. Ontologies can present knowledge in sharable and repeatedly usable manner and provide an effective way to reduce the data volume overhead by encoding the structu...

The exponential growth of the Web and the availability of large number of digital datasets revealed the need for integrated access to heterogeneous and autonomous data sources. In the Cultural Heritage domain, ARIADNE supports transparent integration by means of an advanced metadata schema, based on CIDOC CRM, and adapted to the needs of archaeology. In this paper we present the mappings of two...

Fuzzy relational databases have been extensively studied in recent years, resulting in several models and constructs, some of which are implemented as software layers on top of diverse existing database systems. Fuzzy extensions to query languages and end-user query interfaces have also been developed, but the design of programming interfaces has not been properly addressed. In this paper, we d...

RDF is becoming a core technology in the Semantic Web. Providing the ability to describe metadata information that can be easily navigated, and the ease of storing it in existing relational database systems, have made RDF a very popular way of expressing and exchanging metadata information. However, the use of RDF in dynamic applications over distributed environments that require timely notific...

For relational learning, it is important to know the relationships between the tables. In relational databases, the relationships can be described with foreign key constraints. However, the foreign keys may not be explicitly specified. In this article, we present how to automatically and quickly identify primary & foreign key constraints from metadata about the data. Our method was evaluated on...

The Hadoop Distributed File System (HDFS) scales to store tens of petabytes of data despite the fact that the entire le system's metadata must t on the heap of a single Java virtual machine. The size of HDFS' metadata is limited to under 100 GB in production, as garbage collection events in bigger clusters result in heartbeats timing out to the metadata server (NameNode). In this paper, we addr...

In this demo, we will show the operation of Ultrawrap Mapper, a semi-automatic software for creating mappings from Relational Databases to RDF in the R2RML language. In 2012, the W3C ratified two related standards for mapping relational database contents to RDF: the Direct Mapping [1] and R2RML [2]. The Direct Mapping is a default mapping of relational data to RDF. The organization and content ...

This paper proposes an alternative solution for enhancing the access to the data content. Our solution presents a knowledge discovery architecture concept, whose intention is to implement a communication channel between the Payload Ground Segments and the end-user who receives the content of the data sources coded in an understandable format associated with semantics and ready for the exploitat...

At a minimum, a multimedia database must contain the media itself, plus some level of metadata which describes the media. In early systems, this metadata was limited to simple fields containing basic attributes such as the media title, author, etc. and the user would select media using relational queries on the fields. Video on demand systems are one example of this. More recently, systems have...