Bei der Simulation von eingebetteten Echtzeit Systemen zur Analyse von Ausführungszeiten und Scheduling gibt es immer einen Kompromiss zwischen zyklengenauen Ergebnissen und der Laufzeit der Simulation. Mithilfe von abstrakten RTOS Modellen auf Basis von SystemC wird versucht diese Lücke zu schließen. Aktuelle Arbeiten besitzen allerdings nur unzureichende Möglichkeiten zur Modellierung von Int...

Experimental approaches in concrete technology are time-consuming, laborious and thus expensive. Developments in computer facilities render possible nowadays realistically simulating the particulate structure and microstructure of cementitious materials. For that purpose, discrete element methods (DEM) are required because of more correctly simulating particle dispersion. Dynamic DEMs like Delf...

Empirical research in DEM accuracy assessment has observed that DEM errors are correlated with terrain morphology, sampling density, and interpolation method. However, theoretical reasons for these correlations have not been accounted for. This paper introduces approximation theory adapted from computational science as a new framework to assess the accuracy of DEMs interpolated from topographic...

Aiming at the simulation of dense granular flows, we propose and test a numerical method based on successive convex complementarity problems. This approach originates from a multibody description of the granular flow: all the particles are simulated as rigid bodies with arbitrary shapes and frictional contacts. Unlike the discrete element method (DEM), the proposed approach does not require sma...

A wideband 2-1-1 cascaded ΣΔ modulator with a single-bit quantizer in the two first stages and a 4-bit quantizer in the final stage is developed. To reduce sensitivity of digital-to-analog converter (DAC) nonlinearities in the feedback of the last stage, dynamic element matching (DEM) is introduced. This paper presents two modelling approaches: The first is MATLAB description and the second is ...

An approach for implementing a two dimensional dynamic element matching (DEM) technique for enhancement of a mixed signal WTA tracking system is shown to be achieved. The system consists of a version of a commonly used winner-take-all (WTA) for brightest object tracking, which is traditionally implemented as an analog circuit and suitable for integration with CMOS Active Pixel Sensors (APS). It...

In this paper we introduce an approach that elicits information from psychologists and transfers this knowledge in knowledge representations for a knowledge-based system. Based on SIMOCOSTS, a psychological model for simulating coping strategies in critical situations, we present a case study on a literary character that exemplifies our approach. We describe the simulation sequences in an abstr...

Ein System zur patientenspezifischen Simulation der Transkatheter Aortenklappenimplantation (TAVI) wird vorgestellt. Ausgehend von CT-Bildern wird ein mechanisches Modell der Aortenwurzel und des linken Ventrikels patientenspezifisch ausgeprägt. Zur Beschreibung der mechanischen Eigenschaften kommt ein nichtlineares Multimaterialmodell zum Einsatz. Die Entfaltung eines TAVI-stents in der Aorten...

This paper presents the results of a study aimed at assessing the eŒects of input uncertainty on the outcome of a raster-based model for structural landscape classiŽ cation. The model uses a DEM and a land-cover map as input, and calculates four structural indices from these data. The Ž rst two indices determine the openness of the landscape, the other two determine the degree of landscape homo...

The hydrodynamics and heat transfer of cylindrical gas-solid fluidized beds for polyolefin production was investigated with the two-fluid model (TFM) based on the kinetic theory of granular flow (KTGF). It was found that the fluidized bed becomes more isothermal with increasing superficial gas velocity. This is mainly due to the increase of solids circulation and improvement in gas solid contac...