openHSU – Research Showcase

4512
Research outputs
779
People
140
Organizational Units
109
Projects
31
Conferences
17
Journals
Recent Additions
  • Publication
    Metadata only
    Towards integrated data control for digital twins in industry 4.0
    (RWTH, 2020-06-03)
    Bader, Sebastian R.
    ;
    The Digital Twin is currently a widely discussed topic for presenting and exchanging information on physical assets through vir- tual networks. Especially the digitisation of the manufacturing industry, Industry 4.0, drives the implementation of Digital Twins as part of inte- grated production processes. Hence, the protection of sensitive data be- comes an evident challenge. We contribute by determining the require- ments of current scenarios, the descriptive expressiveness of necessary vocabularies, and by formalising the involved operations. The Asset Ad- ministration Shell is used as a concrete metamodel for Digital Twins and is combined with the data sovereignty and enforcement concepts of the International Data Spaces to illustrate how these concepts can be implemented into a comprehensive Industry 4.0 scenario. Copyright © 2020 for this paper by its authors.
  • Publication
    Metadata only
    A Knowledge Graph for Industry 4.0
    (Springer Nature Switzerland, 2020-05-27)
    Bader, Sebastian R.
    ;
    Grangel-Gonzalez, Irlan
    ;
    Nanjappa, Priyanka
    ;
    Vidal, Maria-Esther
    ;
    One of the most crucial tasks for today’s knowledge workers is to get and retain a thorough overview on the latest state of the art. Especially in dynamic and evolving domains, the amount of relevant sources is constantly increasing, updating and overruling previous methods and approaches. For instance, the digital transformation of manufacturing systems, called Industry 4.0, currently faces an overwhelming amount of standardization efforts and reference initiatives, resulting in a sophisticated information environment. We propose a structured dataset in the form of a semantically annotated knowledge graph for Industry 4.0 related standards, norms and reference frameworks. The graph provides a Linked Data-conform collection of annotated, classified reference guidelines supporting newcomers and experts alike in understanding how to implement Industry 4.0 systems. We illustrate the suitability of the graph for various use cases, its already existing applications, present the maintenance process and evaluate its quality. © Springer Nature Switzerland AG 2020.
  • Publication
    Metadata only
    Complex Query Augmentation for Question Answering over Knowledge Graphs
    (Springer Nature Switzerland, 2019-10-11)
    Abdelkawi, Abdelrahman
    ;
    Zafar, Hamid
    ;
    ;
    Lehmann, Jens
    Question answering systems have often a pipeline architecture that consists of multiple components. A key component in the pipeline is the query generator, which aims to generate a formal query that corresponds to the input natural language question. Even if the linked entities and relations to an underlying knowledge graph are given, finding the corresponding query that captures the true intention of the input question still remains a challenging task, due to the complexity of sentence structure or the features that need to be extracted. In this work, we focus on the query generation component and introduce techniques to support a wider range of questions that are currently less represented in the community of question answering. © Springer Nature Switzerland AG 2019.
  • Publication
    Metadata only
    Toward knowledge-based liver surgery: holistic information processing for surgical decision support
    (Springer, 2015-04-07)
    März, K.
    ;
    Hafezi, M.
    ;
    Weller, T.
    ;
    Saffari, A.
    ;
    Nolden, M.
    ;
    Fard, N.
    ;
    Majlesara, A.
    ;
    Zelzer, S.
    ;
    ;
    Volovyk, M.
    ;
    Gharabaghi, N.
    ;
    Wagner, M.
    ;
    Emami, G.
    ;
    Engelhardt, S.
    ;
    Fetzer, A.
    ;
    Kenngott, H.
    ;
    Rezai, N.
    ;
    Rettinger, A.
    ;
    Studer, R.
    ;
    Mehrabi, A.
    ;
    Maier-Hein, L.
    Purpose: Malignant neoplasms of the liver are among the most frequent cancers worldwide. Given the diversity of options for liver cancer therapy, the choice of treatment depends on various parameters including patient condition, tumor size and location, liver function, and previous interventions. To address this issue, we present the first approach to treatment strategy planning based on holistic processing of patient-individual data, practical knowledge (i.e., case knowledge), and factual knowledge (e.g., clinical guidelines and studies). Methods: The contributions of this paper are as follows: (1) a formalized dynamic patient model that incorporates all the heterogeneous data acquired for a specific patient in the whole course of disease treatment; (2) a concept for formalizing factual knowledge; and (3) a technical infrastructure that enables storing, accessing, and processing of heterogeneous data to support clinical decision making. Results: Our patient model, which currently covers 602 patient-individual parameters, was successfully instantiated for 184 patients. It was sufficiently comprehensive to serve as the basis for the formalization of a total of 72 rules extracted from studies on patients with colorectal liver metastases or hepatocellular carcinoma. For a subset of 70 patients with these diagnoses, the system derived an average of 37 ± 15 assertions per patient. Conclusion: The proposed concept paves the way for holistic treatment strategy planning by enabling joint storing and processing of heterogeneous data from various information sources. © 2015, CARS.
  • Publication
    Metadata only
    Using linked data and Web APIs for automating the pre-processing of medical images
    (RWTH, 2014-10-07)
    Gemmeke, Philipp
    ;
    ;
    Philipp, Patrick
    ;
    Götz, Michael
    ;
    Weber, Christian
    ;
    Kämpgen, Benedikt
    ;
    Nolden, Marco
    ;
    Maier-Hein, Klaus
    ;
    Rettinger, Achim
    Current developments in the health care sector are marked by the increased digitalisation of patient records, the use of electronic devices as supporting tools in patient care, and the employment of sensors (e.g. monitoring devices and surgery recording devices), which contribute directly to the abundance of medical data. However, before any significant benefits can be derived based on these growing data volumes and sources, challenges such as data format heterogeneity, distribution of the data sets, interoperability issues and basic pre-processing have to be addressed. In this paper we present an approach and a concrete architecture that support data consolidation and integration based on Linked Data principles. Furthermore, our solution enables the exible composition and execution of data processing pipelines, based on individual processing steps, exposed through semantically described Web APIs. We demonstrate the applicability of our approach by implementing a specific scenario-Brain Tumour Progression Maps, evaluating the performance of the distributed Web API-based solution in comparison to a local execution, and determining the coverage of derived requirements.
  • Publication
    Metadata only
    Towards enforceable usage policies for industry 4.0
    (RWTH, 2019-11-05)
    Bader, Sebastian R.
    ;
    Controlling the usage of business-critical data is essential for every company. While the upcoming age of Industry 4.0 propagates a seamless data exchange between all participating devices, facilities and companies along the production chain, the required data control mechanisms are lacking behind. We claim that for an effective protection, both access and usage control enforcement is a must-have for organizing Industry 4.0 collaboration networks. Formalized and machine-readable policies are one fundamental building block to achieve the needed trust level for real data-driven collaborations. We explain the current challenges of specifying access and usage control policies and outline respective approaches relying on Semantic Web of Things practices. We analyze the requirements and implications of existing technologies and discuss their shortcomings. Based on our experiences from the specification of the International Data Spaces Usage Control Language, the necessary next steps towards automatically monitored and enforced policies are outlined and research needs formulated. Copyright © 2019 for this paper by its authors.
  • Publication
    Metadata only
    Towards an open-source semantic data infrastructure for integrating clinical and scientific data in cognition-guided surgery
    (SPIE, 2016-03-25)
    Fetzer, Andreas
    ;
    Metzger, Jasmin
    ;
    Katic, Darko
    ;
    März, Keno
    ;
    Wagner, Martin
    ;
    Philipp, Patrick
    ;
    Engelhardt, Sandy
    ;
    Weller, Tobias
    ;
    Zelzer, Sascha
    ;
    Franz, Alfred M.
    ;
    Schoch, Nicolai
    ;
    Heuveline, Vincent
    ;
    ;
    Rettinger, Achim
    ;
    Speidel, Stefanie
    ;
    Wolf, Ivo
    ;
    Kenngott, Hannes
    ;
    Mehrabi, Arianeb
    ;
    Müller-Stich, Beat P.
    ;
    Maier-Hein, Lena
    ;
    Meinzer, Hans-Peter
    ;
    Nolden, Marco
    In the surgical domain, individual clinical experience, which is derived in large part from past clinical cases, plays an important role in the treatment decision process. Simultaneously the surgeon has to keep track of a large amount of clinical data, emerging from a number of heterogeneous systems during all phases of surgical treatment. This is complemented with the constantly growing knowledge derived from clinical studies and literature. To recall this vast amount of information at the right moment poses a growing challenge that should be supported by adequate technology. While many tools and projects aim at sharing or integrating data from various sources or even provide knowledge-based decision support - to our knowledge - no concept has been proposed that addresses the entire surgical pathway by accessing the entire information in order to provide context-aware cognitive assistance. Therefore a semantic representation and central storage of data and knowledge is a fundamental requirement. We present a semantic data infrastructure for integrating heterogeneous surgical data sources based on a common knowledge representation. A combination of the Extensible Neuroimaging Archive Toolkit (XNAT) with semantic web technologies, standardized interfaces and a common application platform enables applications to access and semantically annotate data, perform semantic reasoning and eventually create individual context-aware surgical assistance. The infrastructure meets the requirements of a cognitive surgical assistant system and has been successfully applied in various use cases. The system is based completely on free technologies and is available to the community as an open-source package. © 2016 SPIE.
  • Publication
    Metadata only
    Survey of Semantic Description of REST APIs
    (Springer Science + Business Media, 2013-01-01)
    Verborgh, Ruben
    ;
    Harth, Andreas
    ;
    ;
    Stadtmüller, Steffen
    ;
    Steiner, Thomas
    ;
    Taheriyan, Mohsen
    ;
    Van de Walle, Rik
    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 [247]. In different application scenarios such an agreement requires vendor-specific content types for the individual services to convey the meaning of the communicated data. The idea behind vendor-specific content types is that service providers can reuse content types and service consumers can make use of specific processors for the individual content types. In practice however, we see that many RESTful APIs on the Web simply make use of standard non-specific content types, e.g., text/xml or application/json [150]. Since the agreement on the semantics is only implicit, programmers developing client applications have to manually gain a deep understanding of several APIs from multiple providers. © Springer Science+Business Media New York 2014. All rights are reserved.
  • Publication
    Metadata only
    Automating the Use of Web APIs through Lightweight Semantics
    (Springer, 2012) ;
    Pedrinaci, Carlos
    ;
    Liu, Dong
    ;
    Alvaro, Guillermo
    Web services have already achieved a solid level of acceptance and play a major role for the rapid development of loosely-coupled component-based systems, overcoming heterogeneity within and between enterprises. Current developments in the world of services on the Web are marked by the proliferation of Web APIs and Web applications, commonly referred to as RESTful services, which show high potential and growing user acceptance. Still, despite the achieved progress, the wider adoption of Web APIs is hindered by the fact that their implementation and publication hardly follow any standard guidelines or formats. REST principles are indeed a good step in this direction but the vast majority of the APIs do not strictly adhere to these principles. As a consequence, in order to use them, developers are obliged to manually locate, retrieve, read and interpret heterogeneous documentation, and subsequently develop custom tailored software, which has a very low level of reusability. In summary, most tasks during the life-cycle of services require extensive manual effort and applications based on existing Web APIs suffer from a lack of automation. This tutorial introduces an approach and a set of integrated methods and tools to address this drawback, making services more accessible to both experts and non-expert users, by increasing the level of automation provided during common service tasks, such as the discovery of Web APIs, their composition and their invocation. The tutorial covers i) the conceptual underpinnings, which integrate Web APIs with state of the art technologies from the Web of Data and Semantic Web Services; ii) the presentation of an integrated suite of Web-based tools supporting service users; iii) and hands-on examples illustrating how the tools and technologies can help users in finding and exploiting existing Web APIs. © 2012 Springer-Verlag.
  • Publication
    Metadata only
    Adaptive Service Binding with Lightweight Semantic Web Services
    (Spinger, 2011)
    Pedrinaci, Carlos
    ;
    Lambert, Dave
    ;
    ;
    Liu, Dong
    ;
    Domingue, John
    ;
    Krummenacher, Reto
    Adaptive service selection is acknowledged to provide a certain number of advantages to optimise the service provisioning process or to cater for advanced service brokering. Semantic Web Services, that is services that have been enriched with semantic annotations have often been used for providing adaptive service selection by deferring the binding of services until runtime. Thus far, however, research on Semantic Web Services has mainly been dominated by rich conceptual frameworks such as WSMO and OWL-S which require a significant effort towards the annotation of services and rely on complex reasoning for which there are no efficient solutions that can scale to the Web yet. In this chapter, inline with current trends on the Semantic Web that sacrifice expressivity in favour of performance, we present a novel approach to providing adaptive service selection that relies on simple conceptual models for services and less expressive formalisms for which there currently exist mature and performant implementations. In particular, we present a set of conceptual models defined in RDF(S) that support both Web services and Web APIs and we show how simple templates abstracting user requirements can be automatically transformed into SPARQL to enable service selection in a scalable manner. © 2011 Springer-Verlag/Wien.