Andreas Harth

Andreas Harth
Friedrich-Alexander-University of Erlangen-Nürnberg | FAU

PhD

About

177
Publications
14,570
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
4,405
Citations
Additional affiliations
June 2009 - present
Karlsruhe Institute of Technology
Position
  • Akademischer Rat

Publications

Publications (177)
Preprint
Full-text available
We introduce Stream Containers inspired by the Linked Data Platform as an alternative way to process RDF streams. A Stream Container represents a single RDF data stream that can be accessed in a resource-oriented way which allows for better interoperability with the existing Semantic Web infrastructure. Stream Containers are managed by webservers t...
Chapter
Full-text available
In this chapter, we consider the theoretical foundations for representing knowledge in the Internet of Things context. Specifically, we consider (1) the model-theoretic semantics (i.e., extensional semantics ), (2) the possible-world semantics (i.e., intensional semantics ), (3) the situation semantics , and (4) the cognitive/distributional semanti...
Article
In this article, we review past and current system architectures displaying self-organization in the domain of manufacturing. Based on a corpus of 84 reference papers, we find that multiagent systems (MAS) play a significant role in self-organization, especially MAS featuring bio-inspired algorithms for agent coordination. The emergence of new clas...
Book
This book constitutes the proceedings of the satellite events held at the 17th Extended Semantic Web Conference, ESWC 2020, in May/June 2020. The conference was planned to take place in Heraklion, Crete, Greece, but changed to an online format due to the COVID-19 pandemic. ESWC is a major venue for presenting and discussing the latest scientific re...
Article
Many current web pages include structured data which can directly be processed and used. Search engines, in particular, gather that structured data and provide question answering capabilities over the integrated data with an entity-centric presentation of the results. Due to the decentralized nature of the web, multiple structured data sources can...
Conference Paper
The tutorial covers web technologies for specifying and executing applications involving networked sensors and actuators based on a logical representation of world state and application behaviour.
Article
The W3C's Web of Things working group is aimed at addressing the interoperability problem on the Internet of Things using Linked Data as uniform interface. While Linked Data paves the way towards combining such devices into integrated applications, traditional solutions for specifying the control flow of applications do not work seamlessly with Lin...
Conference Paper
Wir beschreiben die Architektur und die prototypische Umsetzung eines Repositories für VR Assets. Assets bilden die Grundbausteine modular aufgebauter VR-Szenen. Mittels eines Repositories lassen sich Assets nachhaltig verwalten und strukturiert bereitstellen. Der Ansatz des semantischen Asset Repository bietet darüber hinaus Versionierung, Varia...
Article
Full-text available
Data owners are creating an ever richer set of information resources online, and these are being used for more and more applications. Spatial data on the Web is becoming ubiquitous and voluminous with the rapid growth of location-based services, spatial technologies, dynamic location-based data and services published by different organizations. How...
Conference Paper
Linked Data is becoming a stable technology alternative and is no longer only an innovation trend. More and more companies are looking into adapting Linked Data as part of the new data economy. Driven by the growing availability of data sources, solutions are constantly being newly developed or improved in order to support the necessity for data ex...
Article
Full-text available
Several institutions collect statistical data about cities, regions, and countries for various purposes. Yet, while access to high quality and recent such data is both crucial for decision makers and a means for achieving transparency to the public, all too often such collections of data remain isolated and not re-usable, let alone comparable or pr...
Conference Paper
Currently, we are witnessing the rise of new technology-driven trends such as the Internet of Things, Web of Things, and Factories of the Future that are accompanied by an increasingly heterogeneous landscape of highly modularized devices and pervasion of network-accessible "things" within all areas of life. At the same time, we can observe increas...
Conference Paper
A lot of current web pages include structured data which can directly be processed and used. Search engines, in particular, gather that structured data and provide question answering capabilities over the integrated data with an entity-centric presentation of the results. Due to the decentralized nature of the web, multiple structured data sources...
Chapter
The ARVIDA reference architecture is a central result of the ARVDIA project. With the help of well-established web technologies and concepts the reference architecture enables heterogeneous VT systems to become platform independent applications. The reference architecture uses and adopts the principle of RESTful web services and the associated Link...
Chapter
Virtuelle Techniken (VT) haben schon seit vielen Jahren in der Industrie in vielfältiger Weise Eingang gefunden. Ebenso gibt es durchaus umfangreiche, interoperable Anwendungen in anderen Fachdomänen, die auf etablierten, standardisierten Web-Technologien beruhen. Daher liegt es nahe, die unbestreitbaren Vorteile von semantischen Web-Technologien f...
Chapter
This chapter is dealing with cases of user guidance caused by requirements of the industry. Within the scenario „MR-Engineering“ solutions were investigated with which planners and process schedulers with the aid of virtual techniques and individual software-solutions can be supported in the activity practice in future. In the scenario „3D planning...
Article
Full-text available
CrunchBase is a database about startups and technology companies. The database can be searched, browsed, and edited via a website, but is also accessible via an entity-centric HTTP API in JSON format. We present a wrapper around the API that provides the data as Linked Data. The wrapper provides schema-level links to schema.org, Friend-of-a-Friend...
Conference Paper
Virtuelle Techniken (VT) sind weitgehend ausgereift; auf VT aufbauende Systeme sind in interaktiven Anwendungen bereits in der Industrie im Produktiveinsatz. Die Anforderungen in industriellen VT-Systemen ähneln denen von Industrie-4.0-Szenarien sowie denen im Internet der Dinge: Unterschiedlichste Komponenten mit inkompatiblen Datenformaten und Zu...
Conference Paper
We work on converting the metadata of 13 American art museums and archives into Linked Data, to be able to integrate and query the resulting data. While there are many good sources of artist data, no single source covers all artists. We thus address the challenge of building a comprehensive knowledge graph of artists that we can then use to link th...
Conference Paper
Full-text available
In media monitoring users have a clearly defined information need to find so far unknown statements regarding certain entities or relations mentioned in natural-language text. However, commonly used keyword-based search technologies are focused on finding relevant documents and cannot judge the novelty of statements contained in the text. In this w...
Presentation
Full-text available
This part of the QS-SDM tutorial is mainly about the quality of the semantic representations extracted from data in a particular Domain in a form of ontologies. Ensuring quality in this context is a complicated task and requires answering several important questions: - Correctness: Given a Domain, how to ensure that the semantic descriptions extrac...
Conference Paper
Networked applications continuously move towards service-based and modular solutions. At the same time, web technologies, proven to be modular and distributed, are applied to these application areas. However, web technologies have to be adapted to the new characteristics of the involved systems -- no explicit client and server roles, use of heterog...
Conference Paper
Online Analytical Processing (OLAP) promises an interface to analyse Linked Data containing statistics going beyond other interaction paradigms such as follow-your-nose browsers, faceted-search interfaces and query builders. As a new way to interact with statistical Linked Data we define comon OLAP operations on data cubes modelled in RDF and show...
Conference Paper
Full-text available
The growing availability of geospatial data online, the increased use of crowdsourced maps and the advent of geospatial mash-ups have led to systems that deliver data to users after integration from many sources. In such systems, understanding the provenance of geospatial data is crucial for assessing the quality of the data and deciding on whether...
Article
The vision of theWeb of Things (WoT) aims to leverageWeb standards in order to interconnect all types of embedded devices and real-world objects, and thus to make them a part of the WWW. Therefore, WoT aims to build a futureWeb of devices that is truly open, flexible, and scalable. We aim to contribute towards achieving this goal by relying on exis...
Conference Paper
National statistical indicators such as the Gross Domestic Product per Capita are published on the Web by various organisations such as Eurostat, the World Bank and the International Monetary Fund. Uniform access to such statistics will allow for elaborate analysis and visualisations. Though many datasets are also available as Linked Data, heteroge...
Conference Paper
Shipping policies allow for deciding whether a query should be executed at the server, the client or distributed among these two. Given the limitations of public SPARQL endpoints, selecting appropriate shipping plans is crucial for successful query executions without harming the endpoint performance. We present PLANET, a query plan visualizer for s...
Conference Paper
International financial markets rely heavily on information to function. E-finance is "the provision of financial services and markets using electronic communication and computation" (Allen et al., 2002:5-6). Despite many initiatives by regulators and industry, straight-through processing along the financial supply chain (e.g. financial messaging i...
Conference Paper
Full-text available
With the rise of the Semantic Web more and more data become available encoded using the Semantic Web standard RDF. RDF is faced towards machines: designed to be easily processable by machines it is difficult to understand by casual users. Transforming RDF data into human-comprehensible text would facilitate non-experts to assess this information. I...
Conference Paper
In this paper we introduce Spartiqulation, a system that translates SPARQL queries into English text. Our aim is to allow casual end users of semantic applications with limited to no expertise in the SPARQL query language to interact with these applications in a more intuitive way. The verbalization approach exploits domain-independent template-bas...
Conference Paper
Analysts spend a disproportionate amount of time with financial data curation before they are able to compare company performances in an analysis. The Extensible Business Reporting Language (XBRL) for annotating financial facts is suited for automatic processing to increase information quality in financial analytics. Still, XBRL does not solve the...
Conference Paper
Although useful governmental statistics have been published as Linked Data, there are query processing and data pre-processing challenges to allow citizens exploring such multidimensional datasets in pivot tables. In this demo paper we present OLAP4LD, a framework for developers of applications over Linked Data sources reusing the RDF Data Cube Voc...
Chapter
The REST architectural style assumes that client and server form a contract with content negotiation, not only on the data format but implicitly also on the semantics of the communicated data, i.e., an agreement on how the data have to be interpreted. In different application scenarios such an agreement requires vendor-specific content types for th...
Article
Recent studies reveal that publicly available SPARQL endpoints exhibit significant limitations in supporting real-world applications. In order for this querying infrastructure to reach its full potential, more flexible client-server architectures capable of deciding appropriate shipping plans are needed. Shipping plans indicate how the execution of...
Chapter
Full-text available
In this paper we introduce Spartiqulation, a system that translates SPARQL queries into English text. Our aim is to allow casual end users of semantic applications with limited to no expertise in the SPARQL query language to interact with these applications in a more intuitive way. The verbalization approach exploits domain-independent template-bas...
Conference Paper
The success of Linked Data (LD) [1] has enabled an environment in which application data can easily be enriched by the abundance of available information on the Web. Many recent approaches of the Linked Data community go beyond the mere exposure of static data and propose the combination of Linked Data and Representational State Transfer (REST) [3,...
Conference Paper
The Smart Grid aims at making the current electricity grid more efficient, featuring an IT-layer that includes communication flows between a multitude of stakeholders. Its infrastructure is likely to be integrated with other IT-based systems. We argue that in order to enable the integration between already existing large-scale information networks...
Conference Paper
Full-text available
Processing large volumes of RDF data requires sophisticated tools. In recent years, much effort was spent on optimizing native RDF stores and on repurposing relational query engines for large-scale RDF processing. Concurrently, a number of new data management systems---regrouped under the NoSQL (for "not only SQL") umbrella---rapidly rose to promin...
Conference Paper
Statistics published as Linked Data promise efficient extraction, transformation and loading (ETL) into a database for decision support. The predominant way to implement analytical query capabilities in industry are specialised engines that translate OLAP queries to SQL queries on a relational database using a star schema (ROLAP). A more direct app...
Conference Paper
An increasing amount of applications build their functionality on the utilisation and manipulation of web resources. Consequently REST gains popularity with a resource-centric interaction architecture that draws its flexibility from links between resources. Linked Data offers a uniform data model for REST with self-descriptive resources that can be...
Conference Paper
Linked Data vocabulary designers and application developers need means to easily identify relevant vocabularies, to allow them to reuse existing vocabularies and to develop applications making use of Linked Data. We describe a system that provides information about the popularity of classes and properties based on the Billion Triple Challenge data...
Conference Paper
The relevance of many types of data perishes or degrades over time; to support timely decision-making, data integration systems must provide access to live data and should make it easy to incorporate new sources. We outline methods, based on web architecture that enable (near) real-time access to data sources in a variety of formats and access moda...
Conference Paper
A number of approaches combine the principles and technologies of Linked Data and RESTful services. Services and APIs are thus enriched by, and contribute to, the Web of Data. These resource-centric approaches, referred to as Linked APIs, focus on flexibility and the integration capabilities of Linked Data. We use our experience in teaching student...
Conference Paper
We identify three foundational tasks for clients interacting with Web services, and study how to realise these tasks using major paradigms (WS-∗, SemanticWeb Services, RESTful APIs and Linked APIs).We identify relative merits of each approach and point out how the combination of resource-oriented services with Linked Data can enable an interoperabl...
Conference Paper
Full-text available
An increasing amount of data is published and consumed on the Web according to the Linked Data paradigm. In consideration of both publishers and consumers, the temporal dimension of data is important. In this paper we investigate the characterisation and availability of temporal information in Linked Data at large scale. Based on an abstract defini...
Conference Paper
Social network analysis can be used to assess the impact of information published on the web. The spatiotemporal impact of a certain web source on a social network can be of particular interest. We contribute a novel statistical learning algorithm for spatiotemporal impact analysis. To demonstrate our approach we analyze Twitter replies to individu...
Article
There has been a recent, tangible growth in RDF published on the Web in accordance with the Linked Data principles and best practices, the result of which has been dubbed the “Web of Data”. Linked Data guidelines are designed to facilitate ad hoc re-use and integration of conformant structured data–across the Web–by consumer applications; however,...
Article
Much information available on the web is copied, reused or rephrased. The phenomenon that multiple web sources pick up certain information is often called trend. A central problem in the context of web data mining is to detect those web sources that are first to publish information which will give rise to a trend. We present a simple and efficient...
Conference Paper
In recent years, top-k query processing has attracted much attention in large-scale scenarios, where computing only the k "best" results is often sufficient. One line of research targets the so-called top-k join problem, where the k best final results are obtained through joining partial results. In this paper, we study the top-k join problem in a...
Article
Full-text available
Linked Data refers to data published in accordance with a number of principles rooted in web standards. In the past few years we have witnessed a tremendous growth in Linked Data publishing on the web, leading to tens of billions of data items published online. Querying the data is a key functionality required to make use of the wealth of rich inte...
Article
Web search engines are immensly useful for locating docu- ments online. However, with more and more structured data being pub- lished online, the restriction to the hyperdocument model impairs the usefulness for searching and browsing. In contrast, an object-orientated model provides means to firstly integrate data about the same object from multip...
Conference Paper
We present a hierarchical distributed communication and control architecture for Smart Grids. The proposed topology consists of multiple layers to allow for robust and flexible data access and resource allocation in large decentralised Smart Grid systems. We introduce a scenario involving different Smart Grid actors, and develop an architecture usi...
Chapter
Web search engines such as Google, Yahoo! MSN/Bing, and Ask are far from the consummate Web search solution: they do not typically produce direct answers to queries but instead typically recommend a selection of related documents from the Web. We note that in more recent years, search engines have begun to provide direct answers to prose queries ma...
Chapter
Full-text available
With increased dependence on efficient use and inclusion of diverse corporate and Web based data sources for business information analysis, financial information providers will increasingly need agile information integration capabilities. Linked Data is a set of technologies and best practices that provide such a level of agility for information in...
Article
Full-text available
The Web of Data has grown to a size of several billion triples and provides human interface opportunities and challenges beyond those of the traditional Web. Although Linked Data is now generated at a fast pace and very large scale, we ob-serve that browsing and visualisation of Linked Data is still in its infancy. In parallel to the enormous boost...
Chapter
The chapter covers basic functionality pertaining to reasoning with ontologies. We first introduce general methods for detecting and resolving inconsistencies, and then present three plugins that provide reasoning and query functionality. The three plugins are: the reasoning plugin, which allows for standard reasoning tasks, such as materialising i...
Article
The advent of the Web of Data kindled interest in link-traversal (or lookup-based) query processing methods, with which queries are answered via dereferencing a potentially large number of small, interlinked sources. While several algorithms for query evaluation have been proposed, there exists no notion of completeness for results of so-evaluated...
Article
Smart cities and smart grids heavily depend on data being exchanged between a large number of heterogeneous entities. Parts of the data which such systems depend on are relevant to the privacy of individuals, e.g., data about energy consumption or current location. We assume the use of semantic technologies for data representation and exchange, and...
Article
Processing large volumes of Linked Data requires sophisticated methods and tools. In the recent years we have mainly focused on systems based on relational databases and bespoke systems for Linked Data processing. Cloud computing offerings such as SimpleDB or BigQuery, and cloud-enabled NoSQL systems including Cassandra or CouchDB as well as framew...
Article
In this paper, we discuss the architecture and implementation of the Semantic Web Search Engine (SWSE). Following traditional search engine architecture, SWSE consists of crawling, data enhancing, indexing and a user interface for search, browsing and retrieval of information; unlike traditional search engines, SWSE operates over RDF Web data – loo...
Article
Full-text available
A growing amount of Linked Data—graph-structured data accessible at sources distributed across the Web—enables advanced data integration and decision-making applications. Typical systems operating on Linked Data collect (crawl) and pre-process (index) large amounts of data, and evaluate queries against a centralised repository. Given that crawling...
Conference Paper
Full-text available
The amount of available Linked Data on the Web is increasing, and data providers start to publish statistical datasets that comprise numerical data. Such statistical datasets differ significantly from the currently predominant network-style data published on the Web. We explore the possibility of integrating statistical data from multiple Linked Da...
Conference Paper
A sizable amount of data on the Web is currently available via Web APIs that expose data in formats such as JSON or XML. Combining data from different APIs and data sources requires glue code which is typically not shared and hence not reused. We propose Linked Data Services (LIDS), a general, formalised approach for integrating data-providing serv...