Jens Hellmers

Simulation of light scattering by biconcave Cassini ovals using the nullfield method with discrete sources

In this paper the nullfield method with discrete sources (NFM-DS) is applied to analysis of light scattering by biconcave Cassini-like particles, which can be described as oblate discspheres with central concavities on their top and bottom. As far as we know this is a first attempt to apply a modification of the T-matrix method to model such a nonconvex object. The numerical results for different particles under different incident angles obtained by the NFM-DS are presented in the last section of the paper. For result verification the discrete source method (DSM) has been chosen. The comparison of results obtained by using both methods shows very good agreement.

Light scattering simulation by oblate disc spheres using the null field method with discrete sources located in the complex plane

The T-matrix method, which is also known as the null field method (NFM) or extended boundary condition method (EBCM), has established itself as a well known and highly regarded method for calculating light scattering by non-spherical particles. Its biggest advantage is the possibility to obtain all information about the scattering characteristics of the particle and to store it into one matrix. This enables one to do additional investigations with low efforts. Unfortunately the standard NFM fails to converge for particles with extremely non-spherical particle shapes, like long cylinders or coin-like flat cylinders. In this paper we investigate light scattering by finite particles in the form of an oblate disc sphere, which can be described as flat cylinders with a rounded edge. We use an advanced form of the T-matrix method—the null field method with discrete sources (NFM-DS). By presenting light scattering results we would like to demonstrate the potential this advanced NFM-DS offers. It allows one to calculate particle shapes with aspect ratios (relation between radius and thickness of the particle) up to 100:1 and size parameters (relation between radius and wavelength) up to 30.

Empowering User Interfaces for Industrie 4.0

Industrie 4.0 (English translation: Industry 4.0) stands for functional integration, dynamic reorganization, and resource efficiency. Technical advances in control and communication create infrastructures that handle more and more tasks automatically. As a result, the complexity of todays and future technical systems is hidden from the user. These advances, however, come with distinct challenges for user interface design. A central question is: how to empower users to understand, monitor, and control the automated processes of Industrie 4.0? Addressing these design challenges requires a full integration of user-centered design (UCD) processes into the development process. This paper discusses flexible but powerful methods for usability and user experience engineering in the context of Industrie 4.0.