3D-printing : a new challenge for intellectual property?

The most important rights, which state such a balance between these two parties, are the rights of intellectual property. Thus, an important question is to what extent 3D-printing conflicts with intellectual property rights. In general, intellectual property balances the rights between the owners of genuine products and their use through third parties. On the one hand the intellectual property rights give exclusive rights to the genuine owners, on the other hand they give as well some important exceptions for the use of third parts material. Hence, the purpose of this work is to examine, which intellectual property rights are affected by the production of a 3D-printed object. In each of the following chapters I will look at the different categories of intellectual property rights. I will examine in how far the creators of a CAD, the uploaders who upload a CAD on a website for a free or commercial download, the website owners who facilitate that uploads and the printers, whether private or with a commercial purpose, may be in conflict with any intellectual property rights. The most important intellectual property rights, which could be affected, are copyright, patents, registered designs, trade marks and passing off. For the present investigation it will be necessary to have a closer look at the different steps of the developing process of a 3D-printed product. More precisely, we have to differentiate between the creation of the CAD, the uploading of a CAD and finally the home-printing or the printing on demand through a specialised company. The aim of this work is to show how these single steps conflict with intellectual property rights and how the different actors in this process are liable for any infringing activity and in how far their activity is covered by any exception. Furthermore, we will also examine whether current legislation and jurisdiction appropriately address issues brought about by this new technology. Because of the reason, that the issue of 3D-printing in relation to intellectual property is quite a new one, this work will occasionally have a look abroad to other jurisdiction how they already dealt with similar problems. With this in mind, especially the US, European and German jurisdiction and laws will be regarded

Experiences from Transforming a Lecture “Communication Systems” from Presence to Virtual Format during the COVID-19 Pandemic

[EN] This article describes the transitions of an existing lecture “Communication Systems” from a conventional presence format to a virtual format due to the COVID-19 pandemic. The process of transformation, the evolution of the lecture during the virtual semester and the lessons learned are characterized. The changed exam format from presence to virtual format with the experiences are described. Results of a student evaluation at the end of the semester are shown. The lessons learned are summarized also for the time after the COVID-19 pandemic.Fuhrmann, T. (2021). Experiences from Transforming a Lecture “Communication Systems” from Presence to Virtual Format during the COVID-19 Pandemic. En 7th International Conference on Higher Education Advances (HEAd'21). Editorial Universitat Politècnica de València. 297-305. https://doi.org/10.4995/HEAd21.2021.12430OCS29730

Protocol Independent Multicast and Asymmetric Routing

Originally all links in the Internet were assumed to operate bidirectionally. Like many other routing protocols, PIM (protocol independent multicast) is based on this assumption: as will be explained, PIM's concept of using the routers' unicast RIBs (routing information bases) for reverse-path-forwarding is not applicable in networks with uni-directional links. If an additional bidirectional link such as a dial-up connection exists, link-layer tunnelling can overcome these basic routing deficiencies. But in order to achieve a more efficient routing and sustain scalability we argue that multicast and unicast traffic should be distinguished either by an extended link-layer tunnelling or dual RIBs

On the Scaling of Feedback Algorithms for Very Large Multicast Groups

Feedback from multicast group members is vital for many multicast protocols. In order to avoid feedback implosion in very large groups feedback algorithms with well behaved scaling-properties must be chosen. In this paper we analyse the performance of three typical feedback algorithms described in the literature. Apart from the basic trade-off between feedback latency and response duplicates we especially focus on the algorithms' sensitivity to the quality of the group size estimation. Based on this analysis we give recommendations for the choice of well behaved feedback algorithms that are suitable for very large groups

Planned Chaos in Electrical Engineering Education

This paper presents the idea to intentionally introduce planned chaos into electrical engineering lectures and lab courses to improve students’ learning success. The reason to present this idea are several personal experiences in daily teaching. If students experience some uncertainty in their study program, it is seen that they have higher challenges and therefore higher learning success in managing uncertain situations. In these ways, students acquire methodical and social competences to deal with uncertainty and achieve productive results in an unstable working environment. If, however, the chaos is too large, students are over-strained with the situation, distracted from the actual learning targets and consequently learning results will be worse, drop-out rates will increase and they will be frustrated. The beneficial level of uncertainty depends on the student culture, academic progress and personality characteristics. The competence to deal with complex situations is essential for later professional life where unexpected circumstances occur regularly. Introducing planned chaos into lectures and lab courses has not to be confused with a missing didactic concept and is no justification for a bad preparation. Planned chaos is a demanding concept for professors to find the right implementation for an optimized learning outcome. These described findings are experienced from practical work and student evaluations.Fuhrmann, T.; Niemetz, M. (2020). Planned Chaos in Electrical Engineering Education. En 6th International Conference on Higher Education Advances (HEAd'20). Editorial Universitat Politècnica de València. (30-05-2020):95-102. https://doi.org/10.4995/HEAd20.2020.10989OCS9510230-05-202

Transdisciplinary Bachelor Course Connecting Business and Electrical Engineering

[EN] The OTH Regensburg has a broad variety of study programs in technical, business, social and health sciences. Up to now there is no integral connection in the bachelor curricula between business and technical faculties except for some small subjects. The scope of this project is to develop a new course specialization which connects engineering and business thinking. Electrical engineering students should learn basics of business science and how managers think. Business students should vice versa learn fundamentals of engineering and how engineers solve problems. Students from both faculties work together in projects where they act like start-up companies developing a new product and bringing it into the market. It is seen a transdisciplinary effect: These projects gain innovative results between the disciplines compared to student projects of one isolated discipline. Evaluation results from the first two cohorts indicate high student satisfaction, high learning success as well as directions for further improvement.http://ocs.editorial.upv.es/index.php/HEAD/HEAD18Fuhrmann, T.; Niemetz, M. (2018). Transdisciplinary Bachelor Course Connecting Business and Electrical Engineering. Editorial Universitat Politècnica de València. 655-663. https://doi.org/10.4995/HEAD18.2018.8056OCS65566

Convergence of a finite volume scheme to the eigenvalues of a Schrödinger operator

We consider the approximation of a Schrödinger eigenvalue problem arising from the modeling of semiconductor nanostructures by a finite volume method in a bounded domain $OmegasubsetR^d$. In order to prove its convergence, a framework for finite dimensional approximations to inner products in the Sobolev space $H^1_0(Omega)$ is introduced which allows to apply well known results from spectral approximation theory. This approach is used to obtain convergence results for a classical finite volume scheme for isotropic problems based on two point fluxes, and for a finite volume scheme for anisotropic problems based on the consistent reconstruction of nodal fluxes. In both cases, for two- and three-dimensional domains we are able to prove first order convergence of the eigenvalues if the corresponding eigenfunctions belong to $H^2(Omega)$. The construction of admissible meshes for finite volume schemes using the Delaunay-Voronoï method is discussed. As numerical examples, a number of one-, two- and three-dimensional problems relevant to the modeling of semiconductor nanostructures is presented. In order to obtain analytical eigenvalues for these problems, a matching approach is used. To these eigenvalues, and to recently published highly accurate eigenvalues for the Laplacian in the L-shape domain, the results of the implemented numerical method are compared. In general, for piecewise $H^2$ regular eigenfunctions, second order convergence is observed experimentally

Convergence of a finite volume scheme to the eigenvalues of a Schrödinger operator

We consider the approximation of a Schr{\"o}dinger eigenvalue problem arising from the modeling of semiconductor nanostructures by a finite volume method in a bounded domain $\Omega\subset\R^d$. In order to prove its convergence, a framework for finite dimensional approximations to inner products in the Sobolev space $H^1_0(\Omega)$ is introduced which allows to apply well known results from spectral approximation theory. This approach is used to obtain convergence results for a classical finite volume scheme for isotropic problems based on two point fluxes, and for a finite volume scheme for anisotropic problems based on the consistent reconstruction of nodal fluxes. In both cases, for two- and three-dimensional domains we are able to prove first order convergence of the eigenvalues if the corresponding eigenfunctions belong to $H^2(\Omega)$. The construction of admissible meshes for finite volume schemes using the Delaunay-Vorono\"i method is discussed. As numerical examples, a number of one-, two- and three-dimensional problems relevant to the modeling of semiconductor nanostructures is presented. In order to obtain analytical eigenvalues for these problems, a matching approach is used. To these eigenvalues, and to recently published highly accurate eigenvalues for the Laplacian in the L-shape domain, the results of the implemented numerical method are compared. In general, for piecewise $H^2$ regular eigenfunctions, second order convergence is observed experimentally

Electronic states in semiconductor nanostructures and upscaling to semi-classical models

In semiconductor devices one basically distinguishes three spatial scales: The atomistic scale of the bulk semiconductor materials (sub-Angstroem), the scale of the interaction zone at the interface between two semiconductor materials together with the scale of the resulting size quantization (nanometer) and the scale of the device itself (micrometer). The paper focuses on the two scale transitions inherent in the hierarchy of scales in the device. We start with the description of the band structure of the bulk material by kp Hamiltonians on the atomistic scale. We describe how the envelope function approximation allows to construct kp Schroedinger operators describing the electronic states at the nanoscale which are closely related to the kp Hamiltonians. Special emphasis is placed on the possible existence of spurious modes in the kp Schroedinger model on the nanoscale which are inherited from anomalous band bending on the atomistic scale. We review results of the mathematical analysis of these multi-band kp Schroedinger operators. Besides of the confirmation of the main facts about the band structure usually taken for granted, key results are conditions on the coefficients of the kp Schroedinger operator for the nanostructure, which exclude spurious modes and an estimate of the size of the band gap. Using these results, we give an overview of properties of the electronic band structure of strained quantum wells. Further, the assumption of flat-band conditions across the nanostructure allows for upscaling of quantum calculations to state equations for semi-classical models. We demonstrate this approach for parameters such as the quantum corrected band-edges, the effective density of states, the optical response, and the optical peak gain. Further, we apply the kp Schroedinger theory to low gap quantum wells, a case where a proper rescaling of the optical matrix element is necessary to avoid spurious modes. Finally, we discuss the application of the kp Schroedinger models to biased quantum wells, the operation mode of electro-optic modulators

Highly accurate quadrature-based Scharfetter--Gummel schemes for charge transport in degenerate semiconductors

We introduce a family of two point flux expressions for charge carrier transport described by drift-diffusion problems in degenerate semiconductors with non-Boltzmann statistics which can be used in Vorono"i finite volume discretizations. In the case of Boltzmann statistics, Scharfetter and Gummel derived such fluxes by solving a linear two point boundary value problem yielding a closed form expression for the flux. Instead, a generalization of this approach to the nonlinear case yields a flux value given implicitly as the solution of a nonlinear integral equation. We examine the solution of this integral equation numerically via quadrature rules to approximate the integral as well as Newton's method to solve the resulting approximate integral equation. This approach results into a family of quadrature-based Scharfetter-Gummel flux approximations. We focus on four quadrature rules and compare the resulting schemes with respect to execution time and accuracy. A convergence study reveals that the solution of the approximate integral equation converges exponentially in terms of the number of quadrature points. With very few integration nodes they are already more accurate than a state-of-the-art reference flux, especially in the challenging physical scenario of high nonlinear diffusion. Finally, we show that thermodynamic consistency is practically guaranteed