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Stoffel, Kilian
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Stoffel, Kilian
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Voici les éléments 1 - 10 sur 85
- PublicationAccès libreInvestigating Hyperparameter Optimization and Transferability for ES-HyperNEAT: A TPE Approach(2024-08)
; ; Neuroevolution of Augmenting Topologies (NEAT) and its advanced version, Evolvable-Substrate HyperNEAT (ES-HyperNEAT), have shown great potential in developing neural networks. However, their effectiveness heavily depends on the selection of hyperparameters. This study investigates the optimization of ES-HyperNEAT hyperparameters using the Tree-structured Parzen Estimator (TPE) on the MNIST classification task, exploring a search space of over 3 billion potential combinations. TPE effectively navigates this vast space, significantly outperforming random search in terms of mean, median, and best accuracy. During the validation process, the best hyperparameter configuration found by TPE achieves an accuracy of 29.00% on MNIST, surpassing previous studies while using a smaller population size and fewer generations. The transferability of the optimized hyperparameters is explored in logic operations and Fashion-MNIST tasks, revealing successful transfer to the more complex Fashion-MNIST problem but limited to simpler logic operations. This study emphasizes a method to unlock the full potential of neuroevolutionary algorithms and provides insights into the hyperparameters’ transferability across tasks of varying complexity. - PublicationAccès libreSwiss health metadata repository : implementation recommendations - requirements, recommended architecture and prototype implementation(Université de Neuchâtel Institut du management de l'information, 2021-6-1)
; ; ; In the context of a decentralized approach for health data resources, a central metadata repository becomes essential for the identification/description of the necessary resources. A Swiss Health Metadata Repository is expected to enable multiple advantages, namely: to provide a single entry point for searching/retrieving health-related resources; to help identify possible semantic linking between data sources; to provide a consistent data catalog ensured by the use of standardized vocabularies/ontologies; to enable potential exchange of experience and know-how between health data-related projects in Switzerland; and to increase the capacity of research groups to share/access/analyse health related data. This policy brief focuses on the implementation aspects of a proof-of-concept proto-type for Swiss Health Metadata Repository. - PublicationAccès libre
- PublicationAccès libreDesign principles of a central metadata repository as a key element of an integrated health information system(Université de Neuchâtel Institut du management de l'information, 2020-1-31)
; ; ; The Swiss Health System is a complex system with different groups of actors for which data is collected and analyzed using various methods, leading to a large heterogeneity and dispersion of available data. The specificities of a Swiss Health System favor a hybrid infrastructure to manage the heterogeneity and dispersion of Swiss health-related data. This policy brief shows the importance of a metadata management infrastructure to identify and describe health data resources and highlights several essential key elements for the design of a metadata repository and also raises important practical questions. - PublicationAccès libreObject-Oriented Modeling with Ontologies Around: A Survey of Existing Approaches(2018-12-23)
; Despite the many integration tools proposed for mapping between OWL ontologies and the object-oriented paradigm, developers are still reluctant to incorporate ontologies into their code repositories. In this paper we survey existing approaches for OWL-to-OOP mapping trying to identify reasons for this shy adoption of ontologies among conventional software developers. We present a classification of the surveyed approaches and tools based on their technical characteristics and their resulting artifacts. We discuss further potential reasons beyond what have been addressed in the literature before finally providing our own reflection and outlook. - PublicationAccès libreObject-oriented Software Modeling with Ontologies Around(2018-7-1)
; Despite the many integration tools proposed for mapping between OWL ontologies and the object-oriented paradigm, developers are still reluctant to incorporate ontologies into their code repositories. In this paper we survey existing approaches for OWL to OOP mapping trying to identify reasons for this shy adoption of ontologies among conventional software developers. We present a classification of the surveyed approaches and tools based on the characteristics of their resulting artifacts. We finally provide our own reflection for other potential reasons beyond those addressed in the literature. - PublicationAccès libreOntoJIT: Exploiting CLR Compiler Support for Performing Entailment Reasoning over Executable Ontologies(2018-3-13)
; Most recent efforts on bringing ontologies into mainstream programming languages were hindered by some fundamental issues; mainly the lack of expressiveness of programming languages compared to the declarative nature of ontological languages as well as the different assumptions on which reasoning in these languages is based on. In this paper we give the idea of adopting ontological programming approaches a second thought by proposing a prototype for a C# ontological knowledgebase system where ontologies are expressed directly in an executable form. We present our experience on bridging the semantic gab in general purpose programming languages and on exploiting metaprogramming and the dynamic compilation feature of modern compilers for performing certain entailment queries without the need for the bulky ontology classification step usually required in the case of conventional ontological tools. - PublicationMétadonnées seulementProcedural extensions for executable ontologies in conventional software developmentOntologies have gone lengths in various areas of knowledge engineering, yet they are falling short of reaching an equal position as formal domain models in the landscape of enterprise software development. In this paper, we present an approach for integrating ontologies into the code space of conventional software. We argue that the limited adoption of ontologies in software development is partially due to the lack of imperative programming capabilities. We propose extending ontologies with procedural extensions by expressing them in an executable form. Finally, we discuss the advantages of this representation and the possibilities for further improvements.
- PublicationMétadonnées seulement
- PublicationMétadonnées seulementOntoJIT: Parsing Native OWL DL into Executable Ontologies in an Object Oriented ParadigmDespite meriting the growing consensus between researchers and practitioners of ontology modeling, the Web Ontology Language OWL still has a modest presence in the communities of “traditional” web developers and software engineers. This resulted in hoarding the semantic web field in a rather small circle of people with a certain profile of expertise. In this paper we present OntoJIT, our novel approach toward a democratized semantic web where we bring OWL ontologies into the comfort-zone of end-application developers. We focus particularly on parsing OWL source files into executable ontologies in an object oriented programming paradigm. We finally demonstrate the dynamic code-base created as the result of parsing some reference OWL DL ontologies.