Ruben Taelman

Ghent University | UGhent · Department of Electronics and Information Systems

Link traversal–based query processing ( ltqp ), in which a sparql query is evaluated over a web of documents rather than a single dataset, is often seen as a theoretically interesting yet impractical technique. However, in a time where the hypercentralization of data has increasingly come under scrutiny, a decentralized Web of Data with a simple do...

Link Traversal-based Query Processing (ltqp), in which a sparql query is evaluated over a web of documents rather than a single dataset, is often seen as a theoretically interesting yet impractical technique. However, in a time where the hypercentralization of data has increasingly come under scrutiny, a decentralized Web of Data with a simple docu...

To counter societal and economic problems caused by data silos on the Web, efforts such as Solid strive to reclaim private data by storing it in permissioned documents over a large number of personal vaults across the Web. Building applications on top of such a decentralized Knowledge Graph involves significant technical challenges: centralized agg...

The societal and economical consequences surrounding Big Data-driven platforms have increased the call for decentralized solutions. However, retrieving and querying data in more decentralized environments requires fundamentally different approaches, whose properties are not yet well understood. Link Traversal-based Query Processing (LTQP) is a tech...

A common practice within object-oriented software is using composition to realize complex object behavior in a reusable way. Such compositions can be managed by Dependency Injection (DI), a popular technique in which components only depend on minimal interfaces and have their concrete dependencies passed into them. Instead of requiring program code...

The Solid decentralization effort decouples data from services, so that users are in full control over their personal data. In this light, Web Monetization has been proposed as an alternative business model for web services that does not depend on data collection anymore. Integrating Web Monetization with Solid, however, remains difficult because o...

Linked Open Datasets on the Web that are published as RDF can evolve over time. There is a need to be able to store such evolving RDF datasets, and query across their versions. Different storage strategies are available for managing such versioned datasets, each being efficient for specific types of versioned queries. In recent work, a hybrid stora...

Link Traversal–based Query Processing (ltqp), in which a sparql query is evaluated over a web of documents rather than a single dataset, is often seen as a theoretically interesting yet impractical technique. However, in a time where the hypercentralization of data has increasingly come under scrutiny, a decentralized Web of Data with a simple docu...

At the end of 2019, Chinese authorities alerted the World Health Organization (WHO) of the outbreak of a new strain of the coronavirus, called SARS-CoV-2, which struck humanity by an unprecedented disaster a few months later. In response to this pandemic, a publicly available dataset was released on Kaggle which contained information of over 63,000...

Many Web developers nowadays are trained to build applications with a user-facing browser front-end that obtains predictable data structures from a single, well-known back-end. Linked Data invalidates such assumptions, since data can combine several ontologies and span multiple servers with different Open image in new window . Front-end developers,...

The Web is a ubiquitous economic, educational, and collaborative space. However, it also serves as a haven for personal information harvesting. Existing decentralised Web-based ecosystems, such as Solid, aim to combat personal data exploitation on the Web by enabling individuals to manage their data in the personal data store of their choice. Since...

As the building industry is rapidly catching up with digital advancements, and Web technologies grow in both maturity and security , a data-and Web-based construction practice comes within reach. In such an environment, private project information and open online data can be combined to allow cross-domain interoperability at data level, using Seman...

Link-Traversal-Based Query Processing (LTBQP) is a technique for evaluating queries over a web of data by starting with a set of seed documents that is dynamically expanded through following hyperlinks. Compared to query evaluation over a static set of sources, LTBQP is significantly slower because of the number of needed network requests. Furtherm...

Governments typically store large amounts of personal information on their citizens, such as a home address, marital status, and occupation, to offer public services. Because governments consist of various governmental agencies, multiple copies of this data often exist. This raises concerns regarding data consistency, privacy, and access control, e...

Maintaining an Open Dataset comes at an extra recurring cost when it is published in a dedicated Web interface. As there is not often a direct financial return from publishing a dataset publicly, these extra costs need to be minimized. Therefore we want to explore reusing existing infrastructure by enriching existing websites with Linked Data. In t...

The process of extracting, structuring, and organizing knowledge requires processing large and originally heterogeneous data sources. Offering existing data as Linked Data increases its shareability, extensibility, and reusability. However, using Linking Data as a means to represent knowledge can be easier said than done. In this tutorial, we elabo...

When publishing Linked Open Datasets on the Web, most attention is typically directed to their latest version. Nevertheless, useful information is present in or between previous versions. In order to exploit this historical information in dataset analysis, we can maintain history in RDF archives. Existing approaches either require much storage spac...

In order to exploit the value of historical information in Linked Datasets, we need to be able to store and query different versions of such datasets efficiently. The 2018 edition of the Mighty Storage Challenge (MOCHA) is organized to discover the efficiency of such Linked Data stores and to detect their bottlenecks. One task in this challenge foc...

For smart decision making, user agents need live and historic access to open data from sensors installed in the public domain. In contrast to a closed environment, for Open Data and federated query processing algorithms, the data publisher cannot anticipate in advance on specific questions, nor can it deal with a bad cost-efficiency of the server i...

The Linked Open Data cloud is evergrowing and many datasets are frequently being updated. In order to fully exploit the potential of the information that is available in and over historical dataset versions, such as discovering evolution of taxonomies or diseases in biomedical datasets, we need to be able to store and query the different versions o...

rdf Stream Processing (rsp) is a rapidly evolving area of research that focuses on extensions of the Semantic Web in order to model and process Web data streams. While state-of-the-art approaches concentrate on server-side processing of rdf streams, we investigate the Triple Pattern Fragments Query Streamer (tpf-qs) method for server-side publishin...

While humans browse the Web by following links, these hypermedia links can also be used by machines for browsing. While efforts such as Hydra semantically describe the hypermedia controls on Web interfaces to enable smarter interface-agnostic clients, they are largely limited to the input parameters to interfaces, and clients therefore do not know...

Linked Datasets often evolve over time for a variety of reasons. While typical scenarios rely on the latest version only, useful knowledge may still be contained within or between older versions, such as the historical information of biomedical patient data. In order to make this historical information cost-efficiently available on the Web, a low-c...

Linked Datasets typically change over time, and knowledge of this historical information can be useful. This makes the storage and querying of Dynamic Linked Open Data an important area of research. With the current versioning solutions, publishing Dynamic Linked Open Data at Web-Scale is possible, but too expensive. We investigate the possibility...

The process of extracting, structuring, and organizing knowledge from one or multiple data sources and preparing it for the Semantic Web requires a dedicated class of systems. They enable processing large and originally heterogeneous data sources and capturing new knowledge. Offering existing data as Linked Data increases its shareability, extensib...

A large amount of public transport data is made available by many different providers, which makes RDF a great method for integrating these datasets. Furthermore, this type of data provides a great source of information that combines both geospatial and temporal data. These aspects are currently undertested in RDF data management systems, because o...

Linked Data interfaces exist in many flavours, as evidenced by subject pages, SPARQL endpoints, triple pattern interfaces, and data dumps. These interfaces are mostly used to retrieve parts of a complete dataset, such parts can for example be defined by ranges in one or more dimensions. Filtering Linked Data by dimensions such as time range, geospa...

As the amount of generated sensor data is increasing, semantic interoperability becomes an important aspect in order to support efficient data distribution and communication. Therefore, the integration and fusion of (sensor) data is important, as this data is coming from different data sources and might be in different formats. Furthermore, reusabl...

The world contains a large amount of sensors that produce new data at a high frequency. It is currently very hard to find public services that expose these measurements as dynamic Linked Data. We investigate how sensor data can be published continuously on the Web at a low cost. This paper describes how the publication of various sensor data source...

Our society is evolving towards massive data consumption from heterogeneous sources, which includes rapidly changing data like public transit delay information. Many applications that depend on dynamic data consumption require highly available server interfaces. Existing interfaces involve substantial costs to publish rapidly changing data with hig...

Traditional rdf stream processing engines work completely server-side, which contributes to a high server cost. For allowing a large number of concurrent clients to do continuous querying, we extend the low-cost Triple Pattern Fragments (tpf) interface with support for time-sensitive queries. In this poster, we give the overview of a client-side rd...

Existing solutions to query dynamic Linked Data sources extend the sparql language, and require continuous server processing for each query. Traditional sparql endpoints already accept highly expressive queries, so extending these endpoints for time-sensitive queries increases the server cost even further. To make continuous querying over dynamic L...

Existing solutions to query dynamic Linked Data sources extend the SPARQL language, and require continuous server processing for each query. Traditional SPARQL endpoints accept highly expressive queries, contributing to high server cost. Extending these endpoints for time-sensitive queries increases the server cost even further. To make continuous...