Erik Mannens

iMinds - Ghent University · MMLab

This paper analyses the requirements for managing interoperable building data in a federated Common Data Environment (CDE). We discuss the need for generic (meta)data storage patterns, semantic query interfaces, decentral authentication, data aggregation, and adaptation and prove that their combination is feasible with current-day technologies. We...

In many industries, multiple parties collaborate on a larger project. At the same time, each of those stakeholders participates in multiple independent projects simultaneously. A double patchwork can thus be identified, with a many-to-many relationship between actors and collaborative projects. One key example is the construction industry, where ev...

In this paper, we propose a novel data-driven prediction system for Multivariate Time Series (MTS) in an industrial context, where classic relational data contain keyinformation in order to properly interpret the MTS. Particularly we focus on the accurate endpoint prediction of temperature and chemical composition at the basic oxygen furnace, which...

Web-based construction projects are rapidly becoming commonplace. Domain-specific collaboration platforms, the so-called Common Data Environments (CDEs), facilitate complex interactions between the various stakeholders participating in a project. CDEs are developed and maintained by the large BIM companies allowing deep integration with BIM authori...

The quality of knowledge graphs can be assessed by a validation against specified constraints, typically use-case specific and modeled by human users in a manual fashion. Visualizations can improve the modeling process as they are specifically designed for human information processing, possibly leading to more accurate constraints, and in turn high...

Few industries are as fragmented as the building sector: during the life cycle of an asset, countless stakeholders are involved, ranging from direct stakeholders such as the architect, the owner and the facility manager towards indirect data providers like governments or geospatial institutions. This 'federated' reality contrasts with the concept o...

Smart cities need (sensor) data for better decision-making. However, while there are vast amounts of data available about and from cities, an intermediary is needed that connects and interprets (sensor) data on a Web-scale. Today, governments in Europe are struggling to publish open data in a sustainable, predictable and cost-effective way. Our res...

Clinical decision support systems are assisting physicians in providing care to patients. However, in the context of clinical pathway management such systems are rather limited as they only take the current state of the patient into account and ignore the possible evolvement of that state in the future. In the past decade, the availability of big d...

Clinical decision support systems are assisting physicians in providing care to patients. However, in the context of clinical pathway management such systems are rather limited as they only take the current state of the patient into account and ignore the possible evolvement of that state in the future. In the past decade, the availability of big d...

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...

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...

Traditional broadcasters of cycling races are experiencing hard times as the numbers of spectators are decreasing each year. Other ways of reporting are needed to keep the viewer interested. In this paper, two possible solutions are proposed that have been evaluated during the Grand Depart of the Tour de France 2019 in Brussels. The first innovatio...

For better traffic flow and making better policy decisions, the city of Antwerp is connecting traffic lights to the Internet. The live “time to green” only tells a part of the story: also the historical values need to be preserved and need to be made accessible to everyone. We propose (i) an ontology for describing the topology of an intersection a...

Knowledge graphs are often generated using rules that apply semantic annotations to data sources. Software tools then execute these rules and generate or virtualize the corresponding RDF-based knowledge graph. RML is an extension of the W3C-recommended R2RML language, extending support from relational databases to other data sources, such as data i...

Learning dashboards are known to improve decision-making by visualizing learning processes and helping to track where learning processes evolve as expected and where potential issues (may) occur. Despite the popularity of such dashboards, little is known theoretically on the design principles. Our earlier research reports on the gap between dashboa...

When benchmarking RDF data management systems such as public transport route planners, system evaluation needs to happen under various realistic circumstances, which requires a wide range of datasets with different properties. Real-world datasets are almost ideal, as they offer these realistic circumstances, but they are often hard to obtain and in...

Taking the region of Flanders in Belgium as a case study, this article reflects on how smart cities initiated a grassroots initiative on data interoperability. We observe that cities are struggling due to the fragmentation of data and services across different governmental levels. This may cause frustrations in the everyday life of citizens as they...

The transformation of society towards a digital economy and government austerity creates a new context leading to changing roles for both government and private sector. Boundaries between public and private services are blurring, enabling government and private sector to collaborate and share responsibilities. In Belgium, the regional Government of...

Enriching scholarly data with metadata enhances the publications’ meaning. Unfortunately, different publishers of overlapping or complementary scholarly data neglect general-purpose solutions for metadata and instead use their own ad-hoc solutions. This leads to duplicate efforts and entails non-negligible implementation and maintenance costs. In t...

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...

Public service fragmentation across more than 800 digital channels of government administrations in the region of Flanders (Belgium), causes administrative burden and frustrations, as citizens expect a coherent service. Given the autonomy of the various entities, the fragmentation of information and budget constraints, it is not feasible to rewire...

Visual tools are implemented to help users in defining how to generate Linked Data from raw data. This is possible thanks to mapping languages which enable detaching mapping rules from the implementation that executes them. However, no thorough research has been conducted so far on how to visualize such mapping rules, especially if they become larg...

Evaluating federated Linked Data queries requires consulting multiple sources on the Web. Before a client can execute queries, it must discover data sources, and determine which ones are relevant. Federated query execution research focuses on the actual execution, while data source discovery is often marginally discussed-even though it has a strong...

This work reports on early results from CITADEL project that aims at creating an ecosystem of best practices, tools, and recommendations to transform Public Administrations with more efficient, inclusive and citizen-centric services. The goal of the recommendations is to support Governments to find out why citizens stop using public services, and u...

The popularity of digital comic books keeps rising, causing an increase in interest from traditional publishers. Digitizing existing comic books can require much work though, since older comic books were made when digital versions were not taken into account. Additions such as digital panel segmentation and semantic annotation, which increase the d...

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...

dbpedia data is largely generated from extracting and parsing the wikitext from the infoboxes of Wikipedia. This generation process is handled by the dbpedia Extraction Framework (dbpedia ef). This framework currently consists of data transformations, a series of custom hard-coded steps which parse the wikitext, and schema transformations, which mo...

In 2015, Flanders Information started the OSLO² project, aimed at easing the exchange of data and increasing the interoperability of Belgian government services. RDF ontologies were developed to break apart the government data silos and stimulate data reuse. However, ontology design still encounters a number of difficulties. Since domain experts ar...

dbpedia ef, the generation framework behind one of the Linked Open Data cloud’s central interlinking hubs, has limitations with regard to quality, coverage and sustainability of the generated dataset. dbpedia can be further improved both on schema and data level. Errors and inconsistencies can be addressed by amending (i) the dbpedia ef; (ii) the d...

When researchers formulate search queries to find relevant content on the Web, those queries typically consist of keywords that can only be matched in the content or its metadata. The Web of Data extends this functionality by bringing structure and giving well-defined meaning to the content and it enables humans and machines to work together using...

Using Linked Data based approaches, public transport companies are able to share their time tables and its updates in an affordable way while allowing user agents to perform multimodal route planning algorithms. Providing time table updates, usually published as data streams, means that data is being constantly modified and if there is a large anal...

An e-TextBook can serve as an interactive learning environment (ILE), facilitating more effective teaching and learning processes. In this paper, we propose the novel concept of an EPUB 3-based Hybrid e-TextBook, which allows for interaction between the digital and the physical world. In that regard, we first investigated the gap between the expect...

In a previous work, we presented a method to reconstruct W3C PROV derivations from short social media messages. This method can capture a wide range of information spreading (and thus influence) among users, from explicit attribution like quoting to implicit means like content similarity. When applying this method to real-life datasets containing s...

The success of the Semantic Web highly depends on its ingredients. If we want to fully realize the vision of a machine-readable Web, it is crucial that Linked Data are actually useful for machines consuming them. On this background it is not surprising that (Linked) Data validation is an ongoing research topic in the community. However, most approa...

While some public transit data publishers only provide a data dump – which only few reusers can afford to integrate within their applications – others provide a use case limiting origin-destination route planning api. The Linked Connections framework instead introduces a hypermedia api, over which the extendable base route planning algorithm “Conne...

Ontology-Based Data Access systems provide access to non-rdf data using ontologies. These systems require mappings between the non-rdf data and ontologies to facilitate this access. Manually defining such mappings can become a costly process when dealing with large and complex data sources, and/or multiple data sources at the same time. This result...

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 European Data Portal shows a growing number of governmental organisations opening up transport data. As end users need traffic or transit updates on their day-to-day travels, route planners need access to this government data to make intelligent decisions. Developers however, will not integrate a dataset when the cost for adoption is too high....

On dense railway networks "such as in Belgium" train travelers are frequently confronted with overly occupied trains, especially during peak hours. Crowdedness on trains leads to a deterioration in the quality of service and has a negative impact on the well-being of the passenger. In order to stimulate travelers to consider less crowded trains, th...

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...

In the Internet of Things (IoT), data-producing entities sense their environment and transmit these observations to a data processing platform for further analysis. Applications can have a notion of context awareness by combining this sensed data, or by processing the combined data. The processes of combining data can consist both of merging the dy...

The rapid change and heterogeneity of today’s generated data calls for real-time decision making systems that can cope with the presented heterogeneity. In this paper, we present an Ontology Based Event Processing system that bridges the gap between ontology-based reasoning and event processing. We propose both a language and an architecture to per...

While most challenges organized so far in the Semantic Web domain are focused on comparing tools with respect to different criteria such as their features and competencies, or exploiting semantically enriched data, the Semantic Web Evaluation Challenges series, co-located with the ESWC Semantic Web Conference, aims to compare them based on their ou...

There exists an abundance of Linked Data storage solutions, but only few meet the requirements of a production environment with interlinked life sciences data. In such environments, a triple store has to support complex SPARQL queries and handle large datasets with hundreds of millions of triples. The Ontoforce platform DISQOVER offers federated se...

While most challenges organized so far in the Semantic Web domain are focused on comparing tools with respect to different criteria such as their features and competencies, or exploiting semantically enriched data, the Semantic Web Evaluation Challenges series, co-located with the ESWC Semantic Web Conference, aims to compare them based on their ou...

While most challenges organized so far in the Semantic Web domain are focused on comparing tools with respect to different criteria such as their features and competencies, or exploiting semantically enriched data, the Semantic Web Evaluation Challenges series, co-located with the ESWC Semantic Web Conference, aims to compare them based on their ou...

Each government level uses its own different information system. At the same time citizens expect that these governmental levels adopt a user-centric approach and provide instant access to their data or to open government data. Therefore the applications at various government levels need to be interoperable in support of the 'once only-principle':...

Generating Linked Data based on existing data sources requires the modeling of their information structure. This modeling needs the identification of potential entities, their attributes and the relationships between them and among entities. For databases this identification is not required, because a data schema is always available. However, for o...

Semantic Web reasoners are powerful tools that allow the extraction of implicit information from RDF data. This information is reachable through the definition of ontologies and/or rules provided to the reasoner. To achieve this, various algorithms are used by different reasoners. In this paper, we explain how state space search can be applied to p...

Data has been made reusable and machine-interpretable by publishing it as Linked Data. However, Linked Data automatic processing is not fully achieved yet, as manual effort is still needed to integrate existing tools and libraries within a certain technology stack. To enable automatic processing, we propose exposing functions and methods as Linked...

Calculating a public transit route involves taking into account user preferences: e.g., one might prefer trams over buses, one might prefer a slight detour to pass by their favorite coffee bar or one might only be interested in wheelchair accessible journeys. Traditional route planning interfaces do not expose enough features for these kind of ques...

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...

Linked Data generation and publication remain challenging and complicated, in particular for data owners who are not Semantic Web experts or tech-savvy. The situation deteriorates when data from multiple heterogeneous sources, accessed via different interfaces, is integrated, and the Linked Data generation is a long-lasting activity repeated period...

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...

Base registries are trusted authentic information sources controlled by an appointed public administration or organization appointed by the government. Maintaining a base registry comes with extra maintenance costs to create the dataset and keep it up to date. In this paper, we study the possibility to entangle the maintenance of base registries at...

The root of schema violations for RDF data generated from (semi-)structured data, often derives from mappings, which are repeatedly applied and specify how an RDF dataset is generated. The DBpedia dataset, which derives from Wikipedia infoboxes, is no exception. To mitigate the violations, we proposed in previous work to validate the mappings which...

Path-based storytelling with Linked Data on the Web provides users the ability to discover concepts in an entertaining and educational way. Given a query context, many state-of-the-art pathfinding approaches aim at telling a story that coincides with the user’s expectations by investigating paths over Linked Data on the Web. By taking into account...

Evaluating federated Linked Data queries requires consulting multiple sources on the Web. Before a client can execute queries, it must discover data sources, and determine which ones are relevant. Federated query execution research focuses on the actual execution, while data source discovery is often marginally discussed—even though it has a strong...

In modern factories different machines and devices offering their services such as producing parts or simply providing information become more and more important. The number and diversity of such devices is increasing and the task of combining available resources into workflows becomes a challenge which can hardly be handled by a human user. In thi...

Linked Data storage solutions often optimize for low latency querying and quick responsiveness. Meanwhile, in the back-end, offline ETL processes take care of integrating and preparing the data. In this paper we explain a workflow and the results of a benchmark that examines which Linked Data storage solution and setup should be chosen for differen...

In this paper, we revisit our method for reconstructing the primary sources of documents, which make up an important part of their provenance. Our method is based on the assumption that if two documents are semantically similar, there is a high chance that they also share a common source. We previously evaluated this assumption on an excerpt from a...

Biodiversity is essential to life on Earth and motivates many efforts to collect data about species. These data are collected in different places and published in different formats. Researchers use it to extract new knowledge about living things, but it is difficult to retrieve, combine and integrate data sources from different places. This work wi...

Nowadays, the Web has become one of the main sources of biodiversity information. An increasing number of biodiversity research institutions add new specimens and their related information to their biological collections and make this information available on the Web. However, mechanisms which are currently available provide insufficient provenance...

The Public Sector Information directive has made Open Data the default within European Public Sector Bodies. End-user multimodal planners need access to government data to make intelligent route planning decisions. We studied both the needs of the market and the vision of the department of Mobility and Public Works in Flanders by interviewing 6 mar...

The European textile and clothing (henceforth T&C) sector is forced to heavily invest in research and development in order to fight against global competition focused on cheap, fast fashion products. Micro businesses or individuals have trouble keeping up to date with these innovations. TCBL is a Horizon 2020 funded innovation action that started i...

Searching for relationships between Linked Data resources is typically interpreted as a pathfinding problem: looking for chains of intermediary nodes (hops) forming the connection or bridge between these resources in a single dataset or across multiple datasets. In many cases centralizing all needed linked data in a certain (specialized) repository...

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...