Alexander S. Behr

Mr. Alexander S. Behr

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Research Focus & Metrics

Academic Career Length

20Years (2007-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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25 April 2007 in Chemie Ingenieur Technik
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Journal Article
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ABAlexander S. Behr
Alexander S. Behr
AWA. Westfechtel
A. Westfechtel

6 January 2023 in Computers
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LKLukáš Korel
Lukáš Korel
UYUladzislau Yorsh
Uladzislau Yorsh
ABAlexander S. Behr
Alexander S. Behr
NKNorbert Kockmann
Norbert Kockmann
MHMartin Holena
Martin Holena
The paper presents a machine-learning based approach to text-to-ontology mapping. We explore a possibility of matching texts to the relevant ontologies using a combination of artificial neural networks and classifiers. Ontologies are formal specifications of the shared conceptualizations of application domains. While describing the same domain, different ontologies might be created by different domain experts. To enhance the reasoning and data handling of concepts in scientific papers, finding the best fitting ontology regarding description of the concepts contained in a text corpus. The approach presented in this work attempts to solve this by selection of a representative text paragraph from a set of scientific papers, which are used as data set. Then, using a pre-trained and fine-tuned Transformer, the paragraph is embedded into a vector space. Finally, the embedded vector becomes classified with respect to its relevance regarding a selected target ontology. To construct representative embeddings, we experiment with different training pipelines for natural language processing models. Those embeddings in turn are later used in the task of matching text to ontology. Finally, the result is assessed by compressing and visualizing the latent space and exploring the mappings between text fragments from a database and the set of chosen ontologies. To confirm the differences in behavior of the proposed ontology mapper models, we test five statistical hypotheses about their relative performance on ontology classification. To categorize the output from the Transformer, different classifiers are considered. These classifiers are, in detail, the Support Vector Machine (SVM), k-Nearest Neighbor, Gaussian Process, Random Forest, and Multilayer Perceptron. Application of these classifiers in a domain of scientific texts concerning catalysis research and respective ontologies, the suitability of the classifiers is evaluated, where the best result was achieved by the SVM classifier.

15 July 2023 in Knowledge and Information Systems
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Journal Article
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ABAlexander S. Behr
Alexander S. Behr
MVMarc Völkenrath
Marc Völkenrath
NKNorbert Kockmann
Norbert Kockmann
Ontologies store semantic knowledge in a machine-readable way and represent domain knowledge in controlled vocabulary. In this work, a workflow is set up to derive classes from a text dataset using natural language processing (NLP) methods. Furthermore, ontologies and thesauri are browsed for those classes and corresponding existing textual definitions are extracted. A base ontology is selected to be extended with knowledge from catalysis science, while word similarity is used to introduce new classes to the ontology based on the class candidates. Relations are introduced to automatically reference them to already existing classes in the selected ontology. The workflow is conducted for a text dataset related to catalysis research on methanation of CO $$_2$$ 2 and seven semantic artifacts assisting ontology extension by domain experts. Undefined concepts and unstructured relations can be more easily introduced automatically into existing ontologies. Domain experts can then revise the resulting extended ontology by choosing the best fitting definition of a class and specifying suggested relations between concepts of catalyst research. A structured extension of ontologies supported by NLP methods is made possible to facilitate a Findable, Accessible, Interoperable, Reusable (FAIR) data management workflow.

5 August 2024 in Catalysis Science & Technology
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ABAlexander S. Behr
Alexander S. Behr
DCDiana Chernenko
Diana Chernenko
DKDominik Koßmann
Dominik Koßmann
ANArjun Neyyathala
Arjun Neyyathala
SHSchirin Hanf
Schirin Hanf
NKNorbert Kockmann
Norbert Kockmann
Ontology learning and named entity recognition are used to automate text data extraction from catalysis research and organizing it into a knowledge graph. Extending the CatalysisIE model practical use of the workflow for researchers is demonstrated.

22 November 2022 in International Journal of Online and Biomedical Engineering (iJOE)
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KBKonrad E.R. Boettcher
Konrad E.R. Boettcher
ABAlexander S. Behr
Alexander S. Behr
CTClaudius Terkowsky
Claudius Terkowsky
Although fluid mechanics should be an easy area of physics to learn due to the ubiquity of flows, many students already struggle to understand the basics. Unlike hands-on labs, this is where virtual labs can provide additional interactive visualizations to better facilitate and promote understanding of the fundamental phenomena. However, how can such laboratories be developed for engineering education relatively easily? This contribution presents a simple technical methodology to convert laboratory experiments into a virtual home laboratory. The basis is the representation of arbitrary data in virtual reality. The authors show on the example of a fluid mechanics laboratory experiment a simple numerical method to calculate the flow by using the so-called fictitious domain approach, a procedure to import CFD-calculated fluid-mechanical data into the Unreal engine 4 originally made for development of computer games. As a game engine, it offers high performance so that the virtual environment runs smoothly on ordinary computers without need of special hardware, so also VR-goggles are optionally. In the home laboratory, the flow can be influenced by setting the pressure gradient and we show how to display vector fields, particle motion, residence time, streamlines, information panels, and scalar fields in 3d representation and in arbitrarily set cut planes. Since many of the features cannot be displayed in a real lab, this contribution reflects some possibilities of the design principles of industry 4.0 in a virtual lab.

7 February 2024 in Journal of Cheminformatics
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ABAlexander S. Behr
Alexander S. Behr
HBHendrik Borgelt
Hendrik Borgelt
NKNorbert Kockmann
Norbert Kockmann
As scientific digitization advances it is imperative ensuring data is Findable, Accessible, Interoperable, and Reusable (FAIR) for machine-processable data. Ontologies play a vital role in enhancing data FAIRness by explicitly representing knowledge in a machine-understandable format. Research data in catalysis research often exhibits complexity and diversity, necessitating a respectively broad collection of ontologies. While ontology portals such as EBI OLS and BioPortal aid in ontology discovery, they lack deep classification, while quality metrics for ontology reusability and domains are absent for the domain of catalysis research. Thus, this work provides an approach for systematic collection of ontology metadata with focus on the catalysis research data value chain. By classifying ontologies by subdomains of catalysis research, the approach is offering efficient comparison across ontologies. Furthermore, a workflow and codebase is presented, facilitating representation of the metadata on GitHub. Finally, a method is presented to automatically map the classes contained in the ontologies of the metadata collection against each other, providing further insights on relatedness of the ontologies listed. The presented methodology is designed for its reusability, enabling its adaptation to other ontology collections or domains of knowledge. The ontology metadata taken up for this work and the code developed and described in this work are available in a GitHub repository at: https://github.com/nfdi4cat/Ontology-Overview-of-NFDI4Cat.