Bei Innovationen geht es nicht um Wachstum oder Upscaling, sondern um Ubiquität und Exemplarität

Article for general public (2017)

Internationales Theater und Inter-Kulturen

Book published by Wehrhahn - 2nd ed. revised (2017)

Surface and subsurface continuous gravimetric monitoring of groundwater recharge processes through the karst vadose zone at Rochefort Cave (Belgium)

Scientific Conference (2017, December)

Effective scheme to determine accurate defect formation energies and charge transition levels of point defects in semiconductors

in Physical Review. B : Solid State (2017), 96

We propose an effective method to accurately determine the defect formation energy Ef and charge transition level ε of the point defects using exclusively cohesive energy Ecoh and the fundamental band gap ... [more ▼]

We propose an effective method to accurately determine the defect formation energy Ef and charge transition level ε of the point defects using exclusively cohesive energy Ecoh and the fundamental band gap Eg of pristine host materials. We find that Ef of the point defects can be effectively separated into geometric and electronic contributions with a functional form: Ef = χEcoh + λEg, where χ and λ are dictated by the geometric and electronic factors of the point defects (χ and λ are defect dependent). Such a linear combination of Ecoh and Eg reproduces Ef with an accuracy better than 5% for electronic structure methods ranging from hybrid densityfunctional theory (DFT) to many-body random-phase approximation (RPA) and experiments. Accordingly, ε is also determined by Ecoh/Eg and the defect geometric/electronic factors. The identified correlation is rather general for monovacancies and interstitials, which holds in a wide variety of semiconductors covering Si, Ge, phosphorenes, ZnO, GaAs, and InP, and enables one to obtain reliable values of Ef and ε of the point defects for RPA and experiments based on semilocal DFT calculations. [less ▲]

SchNet: A continuous-filter convolutional neural network for modeling quantum interactions

in 31st Conference on Neural Information Processing Systems (NIPS 2017), Long Beach, CA, USA (2017, December)

100 Jaar Prandtl-Wig: De draagkrachtfactoren

in Geotechniek (2017), December

In 1920 publiseerde Prandtl een artikel over het bezwijken van een materiaal onder een strookbelasting. De bezweken grondmoot is hierbij verdeeld in drie zones, die tezamen de zogenoemde Prandtl-wig ... [more ▼]

In 1920 publiseerde Prandtl een artikel over het bezwijken van een materiaal onder een strookbelasting. De bezweken grondmoot is hierbij verdeeld in drie zones, die tezamen de zogenoemde Prandtl-wig vormen. Prandtl heeft nooit aan de funderingstechnische toepassing gedacht, maar geotechnici vertalen deze oplossing nu als een analytische oplossing voor de draagkracht van de grond onder een strookfundering. Deze oplossing is uitgebreid door Reissner met een bovenbelasting naast de funderingsstrook en door Keverling Buisman en Terzaghi voor het grondgewicht. Terzaghi schreef dit als eerste met drie gescheiden draagkrachtfactoren en Meyerhof als eerste met “inclinatie-” en “shape” factoren, voor de drie afzonderlijke draagkrachtcomponenten; cohesie, bovenbelasting en het grondgewicht. Deze schrijfwijze werd later door Brinch Hansen overgenomen. In dit artikel zijn een groot aantal numerieke berekeningen gemaakt om het bezwijkmechanisme van de Prandtl-wig en de bijbehorende draagkrachtfactoren te controleren. Het blijkt dat het Prandtl-wig bezwijkmechanisme juist is, maar niet in alle gevallen. Ook blijkt dat de analytische oplossingen voor de draagkrachtfactoren die tegenwoordig worden gebruikt, alleen juist zijn voor grond met een onrealistisch hoge dilatantiehoek. [less ▲]

The Time-Varying Risk of Macroeconomic Disasters

Scientific Conference (2017, December)

Computer-based assessments in PISA. Challenges and potentials for research and policy

Speeches/Talks (2017)

A global optimization heuristic for the decomposed static anticipatory network traffic control problem anticipatory network traffic control problem

in Transportation Research Procedia (2017)

Developing traffic control strategies taking explicitly into account the route choice behavior of users has been widely recognized irregularities in the solution space shape, such as non-convexity and non ... [more ▼]

Developing traffic control strategies taking explicitly into account the route choice behavior of users has been widely recognized irregularities in the solution space shape, such as non-convexity and non-smoothness. In this work, we propose an extended as a very challenging problem. Furthermore, the inclusion of user behavior in optimization based control schemes introduces strong decomposition scheme for the anticipatory traffic control problem, based upon our previous contributions, which aims at i) reducing irregularities in the solution space shape, such as non-convexity and non-smoothness. In this work, we propose an extended the computational complexity of the problem by approaching it in a controller-by-controller fashion, and ii) internalizing specific decomposition scheme for the anticipatory traffic control problem, based upon our previous contributions, which aims at i) reducing constraints in the objective function, guiding the optimization process away from non-significant minima, such as flat regions. the computational complexity of the problem by approaching it in a controller-by-controller fashion, and ii) internalizing specific Through two small scale test networks and different, randomly chosen initial points, we compare how the proposed extension constraints in the objective function, guiding the optimization process away from non-significant minima, such as flat regions. influences optimization results with respect to our previously developed decomposed approach, as well as centralized schemes. Through two small scale test networks and different, randomly chosen initial points, we compare how the proposed extension influences optimization results with respect to our previously developed decomposed approach, as well as centralized schemes. [less ▲]

Probabilistic Analysis of Low-Criticality Execution

Scientific Conference (2017, December)

The mixed-criticality toolbox promises system architects a powerful framework for consolidating real-time tasks with different safety properties on a single computing platform. Thanks to the research ... [more ▼]

The mixed-criticality toolbox promises system architects a powerful framework for consolidating real-time tasks with different safety properties on a single computing platform. Thanks to the research efforts in the mixed-criticality field, guarantees provided to the highest criticality level are well understood. However, lower-criticality job execution depends on the condition that all high-criticality jobs complete within their more optimistic low-criticality execution time bounds. Otherwise, no guarantees are made. In this paper, we add to the mixed-criticality toolbox by providing a probabilistic analysis method for low-criticality tasks. While deterministic models reduce task behavior to constant numbers, probabilistic analysis captures varying runtime behavior. We introduce a novel algorithmic approach for probabilistic timing analysis, which we call symbolic scheduling. For restricted task sets, we also present an analytical solution. We use this method to calculate per-job success probabilities for low-criticality tasks, in order to quantify, how low-criticality tasks behave in case of high-criticality jobs overrunning their optimistic low-criticality reservation. [less ▲]