1,301 research outputs found

    Knowledge Search within a Company-WIKI

    Get PDF
    The usage of Wikis for the purpose of knowledge management within a business company is only of value if the stored information can be found easily. The fundamental characteristic of a Wiki, its easy and informal usage, results in large amounts of steadily changing, unstructured documents. The widely used full-text search often provides search results of insufficient accuracy. In this paper, we will present an approach likely to improve search quality, through the use of Semantic Web, Text Mining, and Case Based Reasoning (CBR) technologies. Search results are more precise and complete because, in contrast to full-text search, the proposed knowledge-based search operates on the semantic layer

    A Proof of Kirchhoff's First Law for Hyperbolic Conservation Laws on Networks

    Full text link
    Networks are essential models in many applications such as information technology, chemistry, power systems, transportation, neuroscience, and social sciences. In light of such broad applicability, a general theory of dynamical systems on networks may capture shared concepts, and provide a setting for deriving abstract properties. To this end, we develop a calculus for networks modeled as abstract metric spaces and derive an analog of Kirchhoff's first law for hyperbolic conservation laws. In dynamical systems on networks, Kirchhoff's first law connects the study of abstract global objects, and that of a computationally-beneficial edgewise-Euclidean perspective by stating its equivalence. In particular, our results show that hyperbolic conservation laws on networks can be stated without explicit Kirchhoff-type boundary conditions.Comment: 20 pages, 6 figure

    Synthesis and characterization of metastable transition metal oxides and oxide nitrides

    Get PDF
    New routes to vanadium sesquioxide and tantalum oxide nitride (γ- and δ-phase) are presented. Phase pure V2O3 with bixbyite-type structure, a metastable polymorph, was obtained from vanadium fluoride hydrates at ~750 K. It crystallizes in the cubic crystal system in space group Ia3¯ with lattice parameter a=939.30(5) pm. The catalytical properties of the corresponding oxide nitride phases and their oxidation and reduction solid-state kinetics were investigated. The preparation of γ-TaON as a phase pure sample can be realized by ammonolysis of X-ray amorphous tantalum oxide precursors at 1073 K. This metastable tantalum oxide nitride crystallizes in the monoclinic VO2(B)-type structure in space group C2/m. The same precursors can be used to synthesize the δ-modification with an anatase-type structure at 1023 K. It crystallizes in the tetragonal crystal system in space group I41/amd. A maximum yield of 82 m % could be obtained. The fundamental band gaps of the synthesized and of other metastable TaON polymorphs were calculated from first principles using the GW method. The present results are compared to experimental data and to previous calculations at hybrid DFT level

    Multiblend JET A-1 in practice: results of an R&D project on synthetic paraffinic kerosenes

    Get PDF
    The research and demonstration project, DEMO-SPK, a model project under the German Mobility and Fuel Strategy (MFS), investigated the use of renewable kerosene at the Leipzig/Halle airport. Its primary goal was to examine and verify the behavior of blends consisting of several types of renewable kerosene and fossil JET A-1, under the realistic supply conditions of a major airport. The project demonstrated that the supply chain for multiblend JET A-1 was technically feasible and that the fuel could be used without requiring any changes in the normal operating procedures. The project also confirmed that the use of multiblend JET A-1 resulted in a 30–60% reduction in particulate emissions for ground operations and a reduction in CO2 equivalents, compared with pure fossil JET A-1.The R&D project on the use of renewable kerosene at Leipzig/Halle airport (DEMO-SPK) involved the collaboration of more than 20 international partners from industry and science. It was initiated as a model project of the Mobility and Fuel Strategy (MFS) and financed by the Federal Ministry of Transport and Digital Infrastructure (BMVI)

    Simulation Based Approach for High-Throughput Stacking Processes in Battery Production

    Get PDF
    What are the benefits of simulation-driven design and optimization of stacking processes in battery cell production? This question is addressed within the scope of the paper. This work proposes a method to reduce the effort for model-based design and optimization. Based on three case studies which originate from the development of high-speed stacking processes, this paper illustrates how the relevant loads on the intermediate products are determined with the help of the method. Subsequently, it is shown how the specific material models for battery electrodes and separators are identified, created and validated, as well as how process models are created and process limits are identified and optimized. It was possible to prove how process simulations can be used to minimize the effort required to validate developments and to efficiently determine optimized process parameters for a format and material change in a model-based manner. Consequently, more and more model-based processes should be taken into account during development and start-up in the future.BMBF, 03XP0236A, HoLiB - Hochdurchsatzverfahren in der Fertigung von Lithium-Ionen-BatterienBMBF, 03XP0236B, HoLiB - Hochdurchsatzverfahren in der Fertigung von Lithium-Ionen-BatterienBMBF, 03VP01480, Validierung eines innovativen Verfahrens zur produktivitätsgesteigerten Herstellung von z-gefalteten Lithium-Ionen-Batterien durch eine kontinuierliche Verfahrensführung - KontiBatDFG, 414044773, Open Access Publizieren 2021 - 2022 / Technische Universität Berli

    Neuroevolution of Self-Interpretable Agents

    Full text link
    Inattentional blindness is the psychological phenomenon that causes one to miss things in plain sight. It is a consequence of the selective attention in perception that lets us remain focused on important parts of our world without distraction from irrelevant details. Motivated by selective attention, we study the properties of artificial agents that perceive the world through the lens of a self-attention bottleneck. By constraining access to only a small fraction of the visual input, we show that their policies are directly interpretable in pixel space. We find neuroevolution ideal for training self-attention architectures for vision-based reinforcement learning (RL) tasks, allowing us to incorporate modules that can include discrete, non-differentiable operations which are useful for our agent. We argue that self-attention has similar properties as indirect encoding, in the sense that large implicit weight matrices are generated from a small number of key-query parameters, thus enabling our agent to solve challenging vision based tasks with at least 1000x fewer parameters than existing methods. Since our agent attends to only task critical visual hints, they are able to generalize to environments where task irrelevant elements are modified while conventional methods fail. Videos of our results and source code available at https://attentionagent.github.io/Comment: To appear at the Genetic and Evolutionary Computation Conference (GECCO 2020) as a full pape

    A Selection of Benchmark Problems in Solid Mechanics and Applied Mathematics

    Get PDF
    In this contribution we provide benchmark problems in the field of computational solid mechanics. In detail, we address classical fields as elasticity, incompressibility, material interfaces, thin structures and plasticity at finite deformations. For this we describe explicit setups of the benchmarks and introduce the numerical schemes. For the computations the various participating groups use different (mixed) Galerkin finite element and isogeometric analysis formulations. Some programming codes are available open-source. The output is measured in terms of carefully designed quantities of interest that allow for a comparison of other models, discretizations, and implementations. Furthermore, computational robustness is shown in terms of mesh refinement studies. This paper presents benchmarks, which were developed within the Priority Programme of the German Research Foundation ‘SPP 1748 Reliable Simulation Techniques in Solid Mechanics—Development of Non-Standard Discretisation Methods, Mechanical and Mathematical Analysis’. © 2020, The Author(s)

    OJS Software Workshop Report

    Get PDF
    This report summarizes the achievements of the OJS community members from Germany and Switzerland in the OJS Workshop in Heidelberg University Library, Germany from February 20 and 21, 2020. Main goal of the workshop was to share knowledge and challenges, conceptualize and document problem solving suggestions and collectively develop software in and around OJS. Participants worked on a variety of subjects including data import/export plugins, search functionality, containerization, long-time archiving and XML workflows in and around OJS and OMP. The workshop is a continuation of fruitful meetings within the German OJS user and developer community under auspices of OJS-de.net networ
    • …
    corecore