The Complexity of Linear Tensor Product Problems in (Anti-) Symmetric Hilbert Spaces

We study linear problems defined on tensor products of Hilbert spaces with an additional (anti-) symmetry property. We construct a linear algorithm that uses finitely many continuous linear functionals and show an explicit formula for its worst case error in terms of the singular values of the univariate problem. Moreover, we show that this algorithm is optimal with respect to a wide class of algorithms and investigate its complexity. We clarify the influence of different (anti-) symmetry conditions on the complexity, compared to the classical unrestricted problem. In particular, for symmetric problems we give characterizations for polynomial tractability and strong polynomial tractability in terms of the amount of the assumed symmetry. Finally, we apply our results to the approximation problem of solutions of the electronic Schr\"odinger equation.Comment: Extended version (53 pages); corrected typos, added journal referenc

Konstruktivistisch orientierte Vermittlung von Human Computer Interaction

In unserer heutigen dynamischen Welt wird es beim Lehren und Lernen von neuen Wissensinhalten immer notwendiger, sich von den älteren Lehr- und Lerntheorien zu lösen und sich neuen, moderneren, aber auch risikoreicheren Theorien wie dem Konstruktivismus zuzuwenden. Die Wissensvermittlung sollte nicht mehr als reine Transaktion von Inhalten angesehen werden, sondern sollte sich im Idealfall an den Kenntnissen und Interessen der einzelnen Lernenden orientieren. Durch den Einsatz von didaktischen Mitteln, die auf den konstruktivistischen Lehr- und Lerntheorien beruhen, ist es für Lernende einfacher, die übermittelten Inhalte in ihr bestehendes Wissen zu gliedern und in späterer Folge darauf aufzubauen. Dabei soll sich der Lernvorgang selbst als ein aktiver Prozess gestalten. In dieser Arbeit wird ein didaktisches Modell, aufbauend auf den konstruktivistischen Lehr- und Lerntheorien, vorgestellt, welches der Vermittlung von Inhalten zur Thematik „Human Computer Interaction“ im Rahmen einer Lehrveranstaltung mit Übungscharakter dienen soll. Dabei steht nicht die reine Informationsvermittlung im Vordergrund, sondern eher die Einbettung der Inhalte in bestehende Erlebnisse, um diese in späterer Folge individuell anwenden zu können. Es wird ein großer Augenmerk darauf gelegt, dass die Lernenden sich das Wissen selbst anhand von Experimenten bzw. Projektarbeiten selbst konstruieren und in einem sozialen Umfeld darüber Diskurse halten können. Im Rahmen dieser Arbeit werden daher zu jeden Themengebieten zahlreiche Beispiele, sowie Aufgaben, Übungen und Denkanstöße präsentiert, anhand deren die Teilnehmer sich die Wissensinhalte aktiv verinnerlichen.In todays dynamic environment teaching and learning new knowledge may include shaking off outdated learning theories. Instead, dedicating oneself to recent and modern - yet possible risky - learning theories like the constructivism may be the right call. The knowledge transfer should not be considered literally as a process of transfer. Ideally, teaching knowledge should orientate itself to existing knowlegde and interests of every single scholar. Applying didactic methods based upon the theory of constructivism alleviates the integration of new knowledge in existing patterns of every learner. Therefore it is easier to recall and use that knowledge in later occasions. The process of learning itself should be considered as an active part of the knowledgte transfer. In this master thesis a didactic paradigm based upon the learning theory of constructivism will be introduced to teach the subject of human computer interaction within a course. As already mentioned embedding new knowledge in existing patterns in favor of using that knowledge individually is the main focus of this course. Learners should focus on creating their own knowledge by experimenting with the main topics and working together on a project thesis. Furthermore the social aspects of learning like discussing a topic is another important aspect. Every single topic introduced in this thesis will include ist own examples, exercies as well as challenges and thought provoking impulses that will be presented to future learners

A Design Framework for Adaptive Gamification Applications

The application of gamification does not always achieve the expected results due to the shortcomings of the quite common one size fits all approach of standard gamification concepts. We therefore propose a design framework that can inform systematic development of adaptive gamification applications. The developed framework draws on the current body of gamification literature, focusing on the emerging research stream of adaptive gamification. It provides design paths and design principles that translate the individual elements into concrete guidelines to assist the design practice. The framework has been successfully applied to the design and implementation of a prototype application using gamification to incentivize knowledge exchange on an existing online platform for physicians in practical medical training. The evaluation in a case study indicated positive user acceptance and increased system usage after the introduction of the developed adaptive gamification solution

Wideband Array for C, X, and Ku-Band Applications with 5.3:1 Bandwidth

Satellite communication has largely been accomplished using reflector antennas. However, such antennas are inherently bulky, and rely on mechanical steering. For this reason, ultra-wideband (UWB) and beam forming arrays have received strong interest. These lower weight, size,and cost arrays can combine many satellite applicationsspread throughout the CKa bands (440 GHz).To this end, we seek to develop an UWB Tightly-Coupled Dipole Array (TCDA) with the following attributes: UWB band operation (3.518.5 GHz) with low loss; 45 or more scanning in all planes; Low-cost Printed Circuit Board (PCB) fabrication; Scalable to Ka-band and above

An Ultra-Wideband Millimeter-Wave Phased Array

Wideband millimeter-wave arrays are of increasing importance due to their growing use in high data rate systems, including 5G communication networks. In this paper, we present a new class of ultra-wideband millimeter wave arrays that operate from nearly 20 GHz to 90 GHz. The array is based on tightly coupled dipoles. Feeding designs and fabrication challenges are presented, and a method for suppressing feed resonances is provided

24-71 GHz PCB Array for 5G ISM

Millimeter-wave 5G mobile architectures need to consolidate disparate frequency bands into a single, multifunctional array. Existing arrays are either narrow-band, prohibitively expensive or cannot be scaled to these frequencies. In this paper, we present the first ultra-wideband millimeter wave array to operate across six 5G and ISM bands spanning 24-71 GHz. Importantly, the array is realized using low-cost PCB. The paper presents the design and optimized layout, and discusses fabrication and measurements

Ultra-Wideband Array in PCB for Millimeter-Wave 5G and ISM

Growing mobile data consumption has prompted the exploration of the millimeter-wave spectrum for large bandwidth, high speed communications. However, the allocated bands are spread across a wide swath of spectrum: Fifth generation mobile architecture (5G): 28, 38, 39, 6471 GHz; Industrial, Scientific, and Medical bands (ISM): 24, 60 GHz. Moreover, high gain phased arrays are required to overcome the significant path loss associated with these frequencies. Further, it is necessary to incorporate several of these applications in a single, small size and low cost platform. To this end, we have developed a scanning, Ultra-Wideband (UWB) array which covers all 5G, ISM, and other mm-W bands from 2472 GHz. Critically, this is accomplished using mass-production Printed Circuit Board (PCB) fabrication. The results of this work are presented in this poster

Movable Thin Glass Elements in Façades

Façades play an important role in the control of energy flow and energy consumption in buildings as they represent the interface between the outdoor environment and the indoor occupied space. The option of regulating internal and external conditions acquires great relevance in new approaches to sustainable building solutions. Studies on climate adaptive façades show a very high potential for improved indoor environmental quality conditions and energy savings by moveable façades. A number of movable façades were realized in the past, but the use of thin glass with a thickness of 0.5 mm to 3 mm opens a brand-new field, that allows for playing with the geometry of the outer skin and the opportunity to make it adaptive by movement. Thin glass requires for curved surfaces in order to gain structural stiffness in static use. In kinetic façades the high flexibility of thin glass allows for new options for changes in size and position by bending of elements rather than implementing hinges in a system of foldable rigid panels. The geometry is based on the known theory of developable surfaces for keeping a low stress-level during movement. This allows for façades created from cold bent thin glass or curved laminated safety glasses produced by laminating of thin glass plies which provide better sealing, greater simplicity in construction and robustness and durability of moveable components which may be actuated autonomously. Some concepts based on the before mentioned theories were created to explain some principles and discuss their principles and applicability