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Um medizinische Behandlungsverfahren in der Praxis besser verstehen und anwenden zu können, gewinnt die Visualisierung der Prozesse an immer größerer Bedeutung. Durch Anwendung der Computer-Simulationssoftware CST können elektromagnetische und thermische Simulationen zur Analyse verschiedener Herzrhythmusstörungen durchgeführt werden. Eine weitere Form der Visualisierung erfolgt durch haptische, dreidimensionale Druckmodelle. Diese Modelle können mit einem generativen Herstellungsverfahren, wie z. B. einem 3D-Drucker, in kürzester Zeit hergestellt werden.
Printed electronics (PE) is a fast-growing field with promising applications in wearables, smart sensors, and smart cards, since it provides mechanical flexibility, and low-cost, on-demand, and customizable fabrication. To secure the operation of these applications, true random number generators (TRNGs) are required to generate unpredictable bits for cryptographic functions and padding. However, since the additive fabrication process of the PE circuits results in high intrinsic variations due to the random dispersion of the printed inks on the substrate, constructing a printed TRNG is challenging. In this article, we exploit the additive customizable fabrication feature of inkjet printing to design a TRNG based on electrolyte-gated field-effect transistors (EGFETs). We also propose a printed resistor tuning flow for the TRNG circuit to mitigate the overall process variation of the TRNG so that the generated bits are mostly based on the random noise in the circuit, providing a true random behavior. The simulation results show that the overall process variation of the TRNGs is mitigated by 110 times, and the generated bitstream of the tuned TRNGs passes the National Institute of Standards and Technology - Statistical Test Suite. For the proof of concept, the proposed TRNG circuit was fabricated and tuned. The characterization results of the tuned TRNGs prove that the TRNGs generate random bitstreams at the supply voltage of down to 0.5 V. Hence, the proposed TRNG design is suitable to secure low-power applications in this domain.
A Gamified and Adaptive Learning System for Neurodivergent Workers in Electronic Assembling Tasks
(2020)
Learning and work-oriented assistive systems are often designed to fit the workflow of neurotypical workers. Neurodivergent workers and individuals with learning disabilities often present cognitive and sensorimotor characteristics that are better accommodated with personalized learning and working processes. Therefore, we designed an adaptive learning system that combines an augmented interaction space with user-sensitive virtual assistance to support step-by-step guidance for neurodivergent workers in electronic assembling tasks. Gamified learning elements were also included in the interface to provide self-motivation and praise whenever users progress in their learning and work achievements.
In this work a method for the estimation of current slopes induced by inverters operating interior permanent magnet synchronous machines is presented. After the derivation of the estimation algorithm, the requirements for a suitable sensor setup in terms of accuracy, dynamic and electromagnetic interference are discussed. The boundary conditions for the estimation algorithm are presented with respect to application within high power traction systems. The estimation algorithm is implemented on a field programmable gateway array. This moving least-square algorithm offers the advantage that it is not dependent on vectors and therefore not every measured value has to be stored. The summation of all measured values leads to a significant reduction of the required storage units and thus decreases the hardware requirements. The algorithm is designed to be calculated within the dead time of the inverter. Appropriate countermeasures for disturbances and hardware restrictions are implemented. The results are discussed afterwards.
This paper presents a novel low-jitter interface between a low-cost integrated IEEE802.11 chip and a FPGA. It is designed to be part of system hardware for ultra-precise synchronization between wireless stations. On physical level, it uses Wi-Fi chip coexistence signal lines and UART frame encoding. On its basis, we propose an efficient communication protocol providing precise timestamping of incoming frames and internal diagnostic mechanisms for detecting communication faults. Meanwhile it is simple enough to be implemented both in low-cost FPGA and commodity IEEE802.11 chip firmware. The results of computer simulation shows that developed FPGA implementation of the proposed protocol can precisely timestamp incoming frames as well as detect most of communication errors even in conditions of high interference. The probability of undetected errors was investigated. The results of this analysis are significant for the development of novel wireless synchronization hardware.
Advances in printed electronics (PE) enables new applications, particularly in ultra-low-cost domains. However, achieving high-throughput printing processes and manufacturing yield is one of the major challenges in the large-scale integration of PE technology. In this article, we present a programmable printed circuit based on an efficient printed lookup table (pLUT) to address these challenges by combining the advantages of the high-throughput advanced printing and maskless point-of-use final configuration printing. We propose a novel pLUT design which is more efficient in PE realization compared to existing LUT designs. The proposed pLUT design is simulated, fabricated, and programmed as different logic functions with inkjet printed conductive ink to prove that it can realize digital circuit functionality with the use of programmability features. The measurements show that the fabricated LUT design is operable at 1 V.
Printed electronics (PE) enables disruptive applications in wearables, smart sensors, and healthcare since it provides mechanical flexibility, low cost, and on-demand fabrication. The progress in PE raises trust issues in the supply chain and vulnerability to reverse engineering (RE) attacks. Recently, RE attacks on PE circuits have been successfully performed, pointing out the need for countermeasures against RE, such as camouflaging. In this article, we propose a printed camouflaged logic cell that can be inserted into PE circuits to thwart RE. The proposed cell is based on three components achieved by changing the fabrication process that exploits the additive manufacturing feature of PE. These components are optically look-alike, while their electrical behaviors are different, functioning as a transistor, short, and open. The properties of the proposed cell and standard PE cells are compared in terms of voltage swing, delay, power consumption, and area. Moreover, the proposed camouflaged cell is fabricated and characterized to prove its functionality. Furthermore, numerous camouflaged components are fabricated, and their (in)distinguishability is assessed to validate their optical similarities based on the recent RE attacks on PE. The results show that the proposed cell is a promising candidate to be utilized in camouflaging PE circuits with negligible overhead.
… nicht nur in der Energiewirtschaft, sondern auch im positiven und wahrsten Sinne des Wortes in der Fachgruppe PM Windenergie. In über 40 Jahren GPM wurde immer wieder deutlich, dass Projekte und Programme in Wirtschaft und Gesellschaft nicht nur begleitet, sondern auch aus der GPM heraus mitgestaltet werden. Die Entwicklung und die Ergebnisse der Fachgruppe Windenergie machen dies besonders deutlich.
The authentication method of electronic devices, based on individual forms of correlograms of their internal electric noises, is well-known. Specific physical differences in the components – for example, caused by variations in production quality – cause specific electrical signals, i.e. electric noise, in the electronic device. It is possible to obtain this information and to identify the specific differences of the individual devices using an embedded analog-to-digital converter (ADC). These investigations confirm the possibility to identify and authenticate electronic devices using bit templates, calculated from the sequence of values of the normalized autocorrelation function of noise. Experiments have been performed using personal computers. The probability of correct identification and authentication increases with increasing noise recording duration. As a result of these experiments, an accuracy of 98.1% was achieved for a 1 second-long registration of EM for a set of investigated computers.
In this study, a facile method to fabricate a cohesive ion‐gel based gate insulator for electrolyte‐gated transistors is introduced. The adhesive and flexible ion‐gel can be laminated easily on the semiconducting channel and electrode manually by hand. The ion‐gel is synthesized by a straightforward technique without complex procedures and shows a remarkable ionic conductivity of 4.8 mS cm−1 at room temperature. When used as a gate insulator in electrolyte‐gated transistors (EGTs), an on/off current ratio of 2.24×104 and a subthreshold swing of 117 mV dec−1 can be achieved. This performance is roughly equivalent to that of ink drop‐casted ion‐gels in electrolyte‐gated transistors, indicating that the film‐attachment method might represent a valuable alternative to ink drop‐casting for the fabrication of gate insulators.
Wireless communication technologies play a major role to enable megatrends like Internet of Things (IoT) and Industry 4.0. The Narrowband Wireless WAN (NBWWAN) introduced to meet the long range and low power requirements of spatially distributed wireless communication use cases. These networks introduce additional challenges in testing because the network topology and RF characteristics become particularly complex and thus a multitude of different scenarios must be tested. This paper describes the infrastructure for automated testing of radio communication and for systematic measurements of the network performance of NBWWAN.
Financing trade and development sustainably will be crucial for Africa. Enhanced collaboration between multilateral development banks, development finance institutions and ECAs could greatly enhance intra-regional trade. Furthermore, setting up a ‘level playing field’ on the continent will allow governments to make strategic interventions for successful export credits and trade finance solutions, fostering growth through trade. African trade is already showing signs of rebounding from the coronavirus- induced recession. Through concerted, co-operative and continent-wide efforts, drawing on the knowledge and resources of all types of institutions and policy experts, Africa will continue to grow confidently and quickly into its increasingly important role as an engine of economic growth and global trade.
In this report, we have studied field-effect transistors (FETs) using low-density alumina for electrolytic gating. Device layers have been prepared starting from the structured ITO glasses by printing the In 2 O 3 channels, low-temperature atomic layer deposition (ALD) of alumina (Al 2 O 3 ), and printing graphene top gates. The transistor performance could be deliberately changed by alternating the ambient humidity; furthermore, ID,ON/ID,OFF-ratios of up to seven orders of magnitude and threshold voltages between 0.66 and 0.43 V, decreasing with an increasing relative humidity between 40% and 90%, could be achieved. In contrast to the common usage of Al 2 O 3 as the dielectric in the FETs, our devices show electrolyte-typegating behavior. This is a result from the formation of protons on the Al 2 O 3 surfaces at higher humidities. Due to the very high local capacitances of the Helmholtz double layers at the channel surfaces, the operation voltage can be as low as 1 V. At low humidities (≤30%), the solid electrolyte dries out and the performance breaks down; however, it can fully reversibly be regained upon a humidity increase. Using ALD-derived alumina as solid electrolyte gating material, thus, allows low-voltage operation and provides a chemically stable gating material while maintaining low process temperatures. However, it has proven to be highly humidity-dependent in its performance.
Die entscheidende Frage bei der Konzeption einer möglichen technischen Infrastruktur für Schulen ist keine technische, sondern eine pädagogische: Was soll denn genau gelernt werden, über Rechner und Netzwerke, am Rechner oder mit dem Rechner? Ist diese Frage geklärt, kann man Hard- und Software dafür zusammenstellen.
Rectifiersare vital electronic circuits for signal and power conversion in various smart sensor applications. The ability to process low input voltage levels, for example, from vibrational energy harvesters is a major challenge with existing passive rectifiers in printed electronics, stemming mainly from the built-in potential of the diode's p-njunction. To address this problem, in this work, we design, fabricate, and characterize an inkjet-printed full-wave rectifier using diode-connected electrolyte-gated thin-film transistors (EGTs). Using both experimental and simulation approaches, we investigate how the rectifier can benefit from the near-zero threshold voltage of transistors, which can be enabled by proper channel geometry setting in EGT technology. The presented circuit can be operated at 1-V input voltage, featuring a remarkably small voltage loss of 140 mV and a cutoff frequency of ~300 Hz. Below the cutoff frequency, more than 2.6-μW dc power is obtained over the load resistances ranging from 5 to 20 kQ. Furthermore, experiments show that the circuit can work with an input amplitude down to 500 mV. This feature makes the presented design highly suitable for a variety of energy-harvesting applications.
Analysis of Amplitude and Phase Errors in Digital-Beamforming Radars for Automotive Applications
(2020)
Fundamentally, automotive radar sensors with Digital-Beamforming (DBF) use several transmitter and receiver antennas to measure the direction of the target. However, hardware imperfections, tolerances in the feeding lines of the antennas, coupling effects as well as temperature changes and ageing will cause amplitude and phase errors. These errors can lead to misinterpretation of the data and result in hazardous actions of the autonomous system. First, the impact of amplitude and phase errors on angular estimation is discussed and analyzed by simulations. The results are compared with the measured errors of a real radar sensor. Further, a calibration method is implemented and evaluated by measurements.
Analysis of Miniaturized Printed Flexible RFID/NFC Antennas Using Different Carrier Substrates
(2020)
Antennas for Radio Frequency Identification (RFID) provide benefits for high frequencies (HF) and wireless data transmission via Near Field Communication (NFC) and many other applications. In this case, various requirements for the design of the reader and transmitter antennas must be met in order to achieve a suitable transmission quality. In this work, a miniaturized cost-effective RFID/NFC antenna for a microelectronic measurement system is designed and printed on different flexible carrier substrates using a new and low-cost Direct Ink Writing (DIW) technology. Various practical aspects such as reflection and impedance magnitude as well as the behavior of the printed RFID/NFC antennas are analyzed and compared to an identical copper-based antenna of the same size. The results are presented in this paper. Furthermore, the problems during the printing process itself on the different substrates are evaluated. The effects of the characteristics on the antenna under kink-free bending tests are examined and subsequently long-term measurements are carried out.
Cooling towers or recoolers are one of the major consumers of electricity in a HVAC plant. The implementation and analysis of advanced control methods in a practical application and its comparison with conventional controllers is necessary to establish a framework for their feasibility especially in the field of decentralised energy systems. A standard industrial controller, a PID and a model based controller were developed and tested in an experimental set-up using market-ready components. The characteristics of these controllers such as settling time, control difference, and frequency of control actions are compared based on the monitoring data. Modern controllers demonstrated clear advantages in terms of energy savings and higher accuracy and a model based controller was easier to set-up than a PID.
While prospect of tracking mobile devices' users is widely discussed all over European countries to counteract COVID-19 propagation, we propose a Bloom filter based construction providing users' location privacy and preventing mass surveillance.
We apply a solution based on Bloom filters data structure that allows a third party, a government agency, to perform some privacy-preserving set relations on a mobile telco's access logfile.
By computing set relations, the government agency, given the knowledge of two identified persons, has an instrument that provides a (possible) infection chain from the initial to the final infected user no matter at which location on a worldwide scale they are.
The benefit of our approach is that intermediate possible infected users can be identified and subsequently contacted by the agency. With such approach, we state that solely identities of possible infected users will be revealed and location privacy of others will be preserved. To this extent, it meets General Data Protection Regulation (GDPR)requirements in this area.
The TriRhenaTech alliance presents a collection of accepted papers of the cancelled tri-national 'Upper-Rhine Artificial Intelligence Symposium' planned for 13th May 2020 in Karlsruhe. The TriRhenaTech alliance is a network of universities in the Upper-Rhine Trinational Metropolitan Region comprising of the German universities of applied sciences in Furtwangen, Kaiserslautern, Karlsruhe, and Offenburg, the Baden-Wuerttemberg Cooperative State University Loerrach, the French university network Alsace Tech (comprised of 14 'grandes écoles' in the fields of engineering, architecture and management) and the University of Applied Sciences and Arts Northwestern Switzerland. The alliance's common goal is to reinforce the transfer of knowledge, research, and technology, as well as the cross-border mobility of students.
Astronomical phenomena fascinate people from the very beginning of mankind up to today. In this paper the authors will present their experience with photography of astronomical events. The main focus will be on aurora borealis, comet Neowise, total lunar eclipses and how mobile devices open up new possibilities to observe the green flash. Our efforts were motivated by the great impact and high number of viewers of these events. Visitors from over a hundred countries watched our live broadcasts.
Furthermore, we report on our experiences with the photography of optical phenomena such as polar lights Fig. 1, comet Neowise with a Delta Aquariids meteor Fig. 11, and lunar eclipses Fig. 12.
Innovation ist die Triebfeder wirtschaftlicher Entwicklung. Niemand hat das so früh erkannt und so klar formuliert wie Joseph Schumpeter: „Der fundamentale Antrieb, der die kapitalistische Maschine in Bewegung setzt und hält, kommt von den neuen Konsumgütern, den neuen Produktions- oder Transportmethoden, den neuen Märkten, den neuen Formen der industriellen Organisation, welche die kapitalistische Unternehmung schafft.“
Die Literatur hat in den letzten Jahren einen breiten Diskurs zur Digitalisierung im Rechnungswesen eröffnet. Während die erste Digitalisierungswelle noch grundlegende Digitalisierungsprozesse umfasste, betrifft die zweite Digitalisierungswelle das Unternehmen in seiner Gesamtheit und geht weit über eine digitale Datenverarbeitung hinaus. Digitalisierung reicht daher von der Anwendung grundlegender digitaler Technologien zur Unterstützung von Geschäftsprozessen über Automatisierung betrieblicher Prozesse bis hin zu einer umfassenden digitalen Transformation des gesamten Unternehmens.
Bei dem vorgestellten Ansatz soll der Auftreffpunkt des Pfeils durch die Kreuzkorrelation von Audio-Signalen bestimmt werden. Das Auftreffen des Pfeils erzeugt ein charakteristisches Geräusch, welches von mehreren Mikrofonen in bestimmter Anordnung um die Dartscheibe herum in elektrische Signale umgewandelt wird. Mithilfe der Schallgeschwindigkeit und den Zeitdifferenzen, welche die Schallwelle zu den einzelnen Mikrofonen benötigt soll dann der Auftreffpunkt berechnet werden.
Die Diskussionen über die Bedeutung und Folgen der Digitalisierung sind kaum noch überschaubar. Einig sind sich die meisten, dass Digitalisierung und die sogenannte „Künstliche Intelligenz“ (sKI) sowohl „alternativlos“ wie entscheidend für die Zukunft seien. Wer bei diesen Techniken nicht an der Spitze stünde, würde wirtschaftlich abgehängt und letztlich zum Verlierer. Die erste Frage ist aber: Wer steht denn an der Spitze und ist es erstrebenswert, sich dazu zu gesellen? Die zweite Frage ist, was sich konkret an technischen Systemen hinter Schlagworten wie Big Data, Künstlicher Intelligenz und autonomen Systemen verbirgt. Nicht zuletzt steht in Frage, welche Konsequenzen diese Systeme für den Einzelnen haben (können und/oder werden).
The interaction between agents in multiagent-based control systems requires peer to peer communication between agents avoiding central control. The sensor nodes represent agents and produce measurement data every time step. The nodes exchange time series data by using the peer to peer network in order to calculate an aggregation function for solving a problem cooperatively. We investigate the aggregation process of averaging data for time series data of nodes in a peer to peer network by using the grouping algorithm of Cichon et al. 2018. Nodes communicate whether data is new and map data values according to their sizes into a histogram. This map message consists of the subintervals and vectors for estimating the node joining and leaving the subinterval. At each time step, the nodes communicate with each other in synchronous rounds to exchange map messages until the network converges to a common map message. The node calculates the average value of time series data produced by all nodes in the network by using the histogram algorithm. The relative error for comparing the output of averaging time series data, and the ground truth of the average value in the network will decrease as the size of the network increases. We perform simulations which show that the approximate histograms method provides a reasonable approximation of time series data.
In the modern knowledge-based and digital economy, the value of knowledge is growing relative to other assets and new intellectual property is being created at an ever-increasing rate. Therefore, the ability to find non-trivial solutions, systematically generate new concepts, and create intellectual property rapidly become crucial to achieving competitive advantage and leveraging the intellectual potential of organizations.
Do you know that for each banana bunch the complete plant must be cut as well? Only in Brazil 440 million trees are planted annually. With an average weight of 30 kg per banana plant you can estimate about 13,5 million tons of banana residues per year. Although there exist some projects to use these residues for the production of valuable products (e.g fibers for textile and paper production) most of this organic waste material is unused and left for composting on the farmland.
The basic idea of this project is to evaluate this organic waste material for converting it to a renewable and CO2 neutral fuel. Therefore, the different parts of the banana plant (heart, leaves and pseudo stem) were analyzed regarding their biogas potential (specific biogas yield and biogas production kinetics). In further studies the effect of mechanical and enzymatic pretreatments of the different parts of the plants was investigated. This examination could then be the basis for an energetic usage of this organic residue.
The biogas batch experiments were performed according to the german guideline VDI 4630 in 2-L-Batch reactors at 37°C. As biogas substrates, the heart, the leaves and the pseudo stem of the banana plant residue with and without enzymatic/mechanical pretreatment were used.
The different parts of the banana plants result in a specific biogas production yield in the range of 260-470 norm liters per kg organic dry mass.
To determine the influence of the mechanical pretreatment (particle size 1-15 mm) on the biogas production kinetics, the kinetic constants were defined and calculated. The reduction of the particle size leads to an improved biogas production kinetics. Therefore experiments will demonstrate, if the results from the batch experiments can be converted in the continuous fed biogas reactor. The experiments of the enzymatic pretreatment are still under investigation.
Efficient collaborative robotic applications need a combination of speed and separation monitoring, and power and force limiting operations. While most collaborative robots have built-in sensors for power and force limiting operations, there are none with built-in sensor systems for speed and separation monitoring. This paper proposes a system for speed and separation monitoring directly from the gripper of the robot. It can monitor separation distances of up to three meters. We used single-pixel Time-of-Flight sensors to measure the separation distance between the gripper and the next obstacle perpendicular to it. This is the first system capable of measuring separation distances of up to three meters directly from the robot's gripper.
Well-designed and informative product presentations can support consumers in making purchase decisions. There are plenty of facts and details about a product of interest. However, also emotions are an important aspect for the purchase decision. The unique visualization opportunities of virtual reality (VR) can give users of VR applications the feeling of being there (telepresence). The applications can intensely engage them in a flow experience, comprising the four dimensions of enjoyment, curiosity, focused attention and control. In this work, we claim that VR product presentations can create subjective product experiences for consumers and motivate them to reuse this innovative type of product presentation in the future, by immersing them in a virtual world and causing them to interact with it. To verify the conceptual model a study was conducted with 551 participants who explored a VR hotel application. The results indicate that VR product presentations evoke positive emotions among consumers. The virtual experience made potential customers focus their attention on the virtual world and aroused their curiosity about getting more information about the product in an enjoyable way. In contrast to the theoretical assumption, control did not influence the users’ behavioral intentions to reuse VR product presentation. We conclude that VR product presentations create a feeling of telepresence, which leads to a flow experience that contributes to the behavioral intention of users to reuse VR product presentations in the future.
Co-Designing Assistive Tools to Support Social Interactions by Individuals Living with Deafblindness
(2020)
Deafblindness is a dual sensory impairment that affects many aspects of life, including mobility, access to information, communication, and social interactions. Furthermore, individuals living with deafblindness are under a high risk of social isolation. Therefore, we identified opportunities for applying assistive tools to support social interactions through co-ideation activities with members of the deafblind community. This work presents our co-design approach, lessons learned and directions for designing meaningful assistive tools for dual sensory loss.
Generative adversarial networks (GANs) provide state-of-the-art results in image generation. However, despite being so powerful, they still remain very challenging to train. This is in particular caused by their highly non-convex optimization space leading to a number of instabilities. Among them, mode collapse stands out as one of the most daunting ones. This undesirable event occurs when the model can only fit a few modes of the data distribution, while ignoring the majority of them. In this work, we combat mode collapse using second-order gradient information. To do so, we analyse the loss surface through its Hessian eigenvalues, and show that mode collapse is related to the convergence towards sharp minima. In particular, we observe how the eigenvalues of the G are directly correlated with the occurrence of mode collapse. Finally, motivated by these findings, we design a new optimization algorithm called nudged-Adam (NuGAN) that uses spectral information to overcome mode collapse, leading to empirically more stable convergence properties.
Time Sensitive Networking (TSN) provides mechanisms to enable deterministic and real-time networking in industrial networks. Configuration of these mechanisms is key to fully deploy and integrate TSN in the networks. The IEEE 802.1 Qcc standard has proposed different configuration models to implement a TSN configuration. Up until now, TSN and its configuration have been explored mostly for Ethernet-based industrial networks. However, they are still considered “work-in-progress” for wireless networks. This work focuses on the fully centralized model and describes a generic concept to enable the configuration of TSN mechanisms in wireless industrial networks. To this end, a configuration entity is implemented to conFigure the wireless end stations to satisfy their requirements. The proposed solution is then validated with the Digital Enhanced Cordless Telecommunication ultra-low energy (DECT ULE) wireless communication protocol.
Am 01.10.2019 beschäftigte sich der EuGH mit der Frage, wann und inwieweit das Setzen von Cookies ohne vorherige Einwilligung des Internet-Nutzers zulässig sein könnte. Das Ergebnis ist für die Werbeindustrie zwar eigentlich nicht überraschend, aber dennoch für diese höchst ärgerlich. Die praktischen Folgen hingegen sind bislang etwas irritierend, hat sich doch die Zahl von Pop-Up-Fenstern immens vervielfacht, was jedoch, wie hier gezeigt wird, zumeist entweder überflüssig oder aber nicht hinreichend ist.
Unter dem Deckmantel der Covid-19-Pandemie werden soziale Einrichtungen wie Bildungseinrichtungen oder das Gesundheitssystem systematisch auf Digitalisierung getrimmt. Schon Grundschulkinder werden an die Arbeit am Display gewöhnt und Schulen mit Geldern aus dem Digitalpakt Schule technisch aufgerüstet. Lernsoftware, Schulcloud und Learning Analytics erlauben die Verdatung von Schülerbiographien. Digitale Endgeräte als Leihgabe für Schülerinnen und Schüler bereiten den Fernunterricht für die Zeit nach der Pandemie vor. Auf der Strecke bleiben dabei möglicherweise nicht nur Grundrechte, Privatsphäre und letztlich die Autonomie des Menschen, sondern auch das notwendige Vertrauen in politische Entscheidungen, wenn etwa die Digitalisierung zunehmend aller Lebensbereiche gar nicht mehr hinterfragt wird. Dabei reichen bereits vier Forderungen zur IT-Entwicklung, um demokratisch legitimierte Alternativen von Softwarelösungen zu entwickeln, wie der Streit um die Corona-App gezeigt hat.
Printed Electronics technology is a key-enabler for smart sensors, soft robotics, and wearables. The inkjet printed electrolyte-gated field effect transistor (EGFET) technology is a promising candidate for such applications due to its low-power operation, high field-effect mobility, and on-demand fabrication. Unlike conventional silicon-based technologies, inkjet printed electronics technology is an additive manufacturing process where multiple layers are printed on top of each other to realize functional devices such as transistors and their interconnections. Due to the additive manufacturing process, the technology has limited routing layers. For routing of complex circuits, insulating crossovers are printed at the intersection of routing paths to isolate them. The crossover can alter the electrical properties of a circuit based on specific location on a routing path. In this work, we propose a crossover-aware placement and routing (COPnR) methodology for inkjet-printed circuits by integrating the crossover constraints in our design framework. Our proposed placement methodology is based on a state-of-the-art evolutionary algorithm while the routing optimization is done using a genetic algorithm. The proposed methodology is compared with the industrial standard placement and routing (PnR) tools. On average, the proposed methodology has 38% fewer crossovers and 94% fewer failing paths compared to the industrial PnR tools applied to printed circuit designs.
Emotionen sind Teil jedes menschlichen Wesens: Sie begleiten Konsumenten und Konsumentinnen durch alle Alltagssituationen – auch und insbesondere bei Kaufentscheidungen. Jedoch war es bisher nur bedingt möglich, diese Emotionen im Dialogmarketing genau zu erfassen und zu interpretieren. Die innovative Customer Experience Tracking Methode der Hochschule Offenburg ermöglicht eine verzerrungsreduzierte Messung und Auswertung von Kundenemotionen, die vor, während und nach der Benutzerinteraktion mit Dialogmarketingaktivitäten auftreten. Aus den im Labor oder im Feld gewonnenen Untersuchungsergebnissen lassen sich konkrete Handlungsempfehlungen ableiten, um Dialogmarketingangebote im Offline-, Online- oder crossmedialen Bereich optimal auf die Bedürfnisse und Erwartungen der Kunden und Kundinnen auszurichten.
Das TMKB-Modell beschreibt einen Weg, den persönlichen und unternehmerischen Erfolg im beruflichen Alltag effizient und nachhaltig zu erreichen. Hierbei steht TMKB für den Transfer von Methoden und Kompetenzen in den Beruf. Dieses Modell beachtet die Theorien der Kompetenzentwicklung im Kontext realer Problemstellungen in Unternehmen. Beispielhaft wird das TMKB-Modell in der ersten Stufe mit dem Schwerpunkt Lean- und Projektmanagement erläutert. Die Zielgruppe dieses Ansatzes lässt sich über die der Auszubildenden bis hin zu Studierenden und Berufserfahrenen erweitern.
DE\GLOBALIZE
(2020)
Der Komplexitätsbeitrag als Kriterium für Entscheidungen zur Bereinigung technischer Produkte
(2020)
Die Bereinigung der Produktpalette wird meistens anhand des Umsatzanteils und des Deckungsbeitrags im Zuge der Einführung von Nachfolgeprodukten entschieden. Im vorliegenden Beitrag wird ein Kriterium eingeführt und hergeleitet, das den Beitrag eines Produkts zur Komplexität auf Basis logistikrelevanter Produkteigenschaften quantifiziert. Die Anwendung des Kriteriums wird anhand der Ergebnisse aus einem Praxisbeispiel aufgezeigt.
Computer an allen Schulen (1984), Schulen ans Netz (1996), Digitalpakt Schule (2016): Jede neue Rechnergeneration wird für Schule und Unterricht als notwendig reklamiert. Die Argumente wiederholen sich: PCs, Laptops, heute Tablets seien innovativ, motivationsfördernd und ermöglichten „modernen“ Unterricht. Stand der Wissenschaft ist: Weder Nutzen noch Mehrwert von IT in Schulen sind belegt. Die Digitalisierung dient offensichtlich anderen Interessen. Denn ob Kreidetafel oder Whiteboard: Entscheidend für Lernerfolge sind Lehrpersönlichkeiten, ein gut strukturierter Unterricht und der lernförderliche Umgang miteinander, nicht Medientechnik.
Diffracted waves carry high‐resolution information that can help interpreting fine structural details at a scale smaller than the seismic wavelength. However, the diffraction energy tends to be weak compared to the reflected energy and is also sensitive to inaccuracies in the migration velocity, making the identification of its signal challenging. In this work, we present an innovative workflow to automatically detect scattering points in the migration dip angle domain using deep learning. By taking advantage of the different kinematic properties of reflected and diffracted waves, we separate the two types of signals by migrating the seismic amplitudes to dip angle gathers using prestack depth imaging in the local angle domain. Convolutional neural networks are a class of deep learning algorithms able to learn to extract spatial information about the data in order to identify its characteristics. They have now become the method of choice to solve supervised pattern recognition problems. In this work, we use wave equation modelling to create a large and diversified dataset of synthetic examples to train a network into identifying the probable position of scattering objects in the subsurface. After giving an intuitive introduction to diffraction imaging and deep learning and discussing some of the pitfalls of the methods, we evaluate the trained network on field data and demonstrate the validity and good generalization performance of our algorithm. We successfully identify with a high‐accuracy and high‐resolution diffraction points, including those which have a low signal to noise and reflection ratio. We also show how our method allows us to quickly scan through high dimensional data consisting of several versions of a dataset migrated with a range of velocities to overcome the strong effect of incorrect migration velocity on the diffraction signal.
Laser ultrasound was used to determine dispersion curves of surface acoustic waves on a Si (001) surface covered by AlScN films with a scandium content between 0 and 41%. By including off-symmetry directions for wavevectors, all five independent elastic constants of the film were extracted from the measurements. Results for their dependence on the Sc content are presented and compared to corresponding data in the literature, obtained by alternative experimental methods or by ab-initio calculations.
Optimisation based economic despatch of real-world complex energy systems demands reduced order and continuously differentiable component models that can represent their part-load behaviour and dynamic responses. A literature study of existing modelling methods and the necessary characteristics the models should meet for their successful application in model predictive control of a polygeneration system are presented. Deriving from that, a rational modelling procedure using engineering principles and assumptions to develop simplified component models is applied. The models are quantitatively and qualitatively evaluated against experimental data and their efficacy for application in a building automation and control architecture is established.
(1) Background: Little is known about the baroque composer Domenico Scarlatti (1685-1757), whose life was centred behind closed doors at the royal court in Spain. There are no reports about his illnesses. From his compositions, mainly for harpsichord, an outstanding virtuosity can be read. (2) Case Presentation: In this case report, the only known oil painting of Domenico Scarlatti is presented, on which he is about 50 years old. In it one recognizes conspicuous hands with hints of watch glass nails and drumstick fingers. (3) Discussion: Whether Scarlatti had chronic hypoxia of peripheral body regions as a sign of, e.g., bronchial cancer or a severe heart disease, is not known. (4) Conclusions: The above-mentioned signs recorded in the oil painting, even if they were not interpretable at that time, are clearly represented and recorded for us and are open to diagnostic discussion from today's point of view.
Im Archiv für Kriminologie wurden bislang drei Arbeiten zur 3-D-CAD-Rekonstruktion der ersten "Eisernen Hand" des berühmten Reichsritters Gottfried ("Götz") von Berlichingen (1480-1562) vorgestellt. Mittlerweile sind einige neue Gesichtspunkte herausgearbeitet worden, die hier kurz als Ergänzung mitgeteilt werden sollen.
Im Beitrag wird gezeigt, wie sich die Ackermann’sche Formel zur Polvorgabe bei zeitkontinuierlichen
Ein- und Mehrgrößenzustandsregelungen in einfacher
Weise auf nicht vollständig steuerbare Regelstrecken
erweitern lässt. Das vorgestellte Verfahren basiert
auf einer teilsystemorientierten Zustandstransformation
in Verbindung mit der Einführung zusätzlicher fiktiver Stellgrößen, über die nichtsteuerbare Streckeneigenwerte
formal beeinflusst werden könnten, aber durch Nullsetzen
dieser Stellgrößen nicht beeinflusst werden. Dem
Reglerentwurf vorausgehende Maßnahmen zur Elimination
von nicht steuerbaren Anteilen aus dem Streckenmodell
sind daher nicht erforderlich. Im Vergleich zum Fall
einer vollständig steuerbaren Regelstrecke erfordert die
Anwendung des vorgestellten Verfahrens kaum Mehraufwand,
was am Beispiel eines Eingrößen- und eines Mehrgrößensystems
illustriert wird.
Die Physik des Fahrrades
(2020)
Jeder kann Fahrradfahren, keiner weiß,warum es klappt: Anders als beim Reiten, Laufen oder Skifahren muss man sich mit dem Fahrrad immer vorwärtsbewegen, um nicht umzufallen. Prof. Giel von der Hochschule Offenburg erklärt dieses und andere Geheimnisse des Radfahrens. Zum Beispiel, ob man mit der Fahrradpumpe auch Autoreifen aufpumpen kann, warum normale Fahrradfahrer die Marathon-Distanz schneller als die weltbesten Läufer zurücklegen und welche legalen Tuning-Methoden das eigene Fahrrad noch schneller machen.
Digitale Geschäftsmodelle zeichnen sich oft durch die spezifische Nutzung von proprietären Daten oder Algorithmen aus. Wettbewerbsvorteile von Firmen mit digitalen Geschäftsmodellen sind dann charakterisiert durch Merkmale von erfolgsrelevanter Information und Aspekten von deren Offenlegung − oder bewusst gewählter Intransparenz − die intrinsisch zu asymmetrischer Information führen. Management und Personal der Firma kennen die Erfolgsaussichten und die relevanten Risikofaktoren dann besser als mögliche Kapitalgeber.
Die voranschreitende Digitalisierung ist ein Enabler für Business Analytics wodurch sich wiederum ein weiteres Innovationspotenzial durch dessen Nutzung in der datengetriebenen betrieblichen Entscheidungsunterstützung ergibt. Die Herausforderung besteht nun darin, bereits bei der Planung eines Digitalisierungsprojektes das Potenzial für weitergehende Business Analytics-Anwendungen zu erkennen, um dieses auszuschöpfen. Dabei spielen weniger die Methodenspezialisten, sondern eher die Entscheider in den Fachabteilungen die zentrale Rolle.
Cross-industry innovation is commonly understood as identification of analogies and interdisciplinary transfer or copying of technologies, processes, technical solutions, working principles or models between industrial sectors. In general, creative thinking in analogies belongs to the efficient ideation techniques. However, engineering graduates and specialists frequently lack the skills to think across the industry boundaries systematically. To overcome this drawback an easy-to-use method based on five analogies has been evaluated through its applications by students and engineers in numerous experiments and industrial case studies. The proposed analogies help to identify and resolve engineering contradictions and apply approaches of the Theory of Inventive Problem Solving TRIZ and biomimetics. The paper analyses the outcomes of the systematized analogies-based ideation and outlines that its performance continuously grows with the engineering experience. It defines metrics for ideation efficiency and ideation performance function.
Mass transfer phenomena in membrane fuel cells are complex and diversified because of the presence of complex transport pathways including porous media of very different pore sizes and possible formation of liquid water. Electrochemical impedance spectroscopy, although allowing valuable information on ohmic phenomena, charge transfer and mass transfer phenomena, may nevertheless appear insufficient below 1 Hz. Use of another variable, that is, back pressure, as an excitation variable for electrochemical pressure impedance spectroscopy is shown here a promising tool for investigations and diagnosis of fuel cells.
Background: A disturbed synchronization of the ventricular contraction can cause a highly developed systolic heart failure in affected patients, which can often be explained by a diseased left bundle branch block (LBBB). If medication remains unresponsive, the concerned patients will be treated with a cardiac resynchronization therapy (CRT) system. The aim of this study was to integrate His bundle pacing into the Offenburg heart rhythm model in order to visualize the electrical pacing field generated by His bundle pacing.
Methods: Modelling and electrical field simulation activities were performed with the software CST (Computer Simulation Technology) from Dessault Systèms. CRT with biventricular pacing is to be achieved by an apical right ventricular electrode and an additional left ventricular electrode, which is floated into the coronary vein sinus. This conventional type of biventricular pacing leads to a reduction of the left ventricular ejection fraction. Furthermore, the non-responder rate of the CRT therapy is about one third of the CRT patients.
Results: His bundle pacing represents a physiological alternative to conventional cardiac pacing and cardiac resynchronization. An electrode implanted in the His bundle emits a stronger electrical pacing field than the electrical pacing field of conventional cardiac pacemakers. The pacing of the His bundle was performed by the Medtronic Select Secure 3830 electrode with pacing voltage amplitudes of 3 V, 2 V and 1.5 V in combination with a pacing pulse duration of 1 ms.
Conclusions: Compared to conventional cardiac pacemaker pacing, His bundle pacing is capable of bridging LBBB conduction disorders in the left ventricle. The His bundle pacing electrical field is able to spread via the physiological pathway in the right and left ventricles for CRT with a narrow QRS-complex in the surface ECG.
A disturbed synchronization of the ventricular contraction can cause a highly developed systolic heart failure in affected patients with reduction of the left ventricular ejection fraction, which can often be explained by a diseased left bundle branch block (LBBB). If medication remains unresponsive, the concerned patients will be treated with a cardiac resynchronization therapy (CRT) system. The aim of this study was to integrate His-bundle pacing into the Offenburg heart rhythm model in order to visualize the electrical pacing field generated by His-Bundle-Pacing. Modelling and electrical field simulation activities were performed with the software CST (Computer Simulation Technology) from Dessault Systèms. CRT with biventricular pacing is to be achieved by an apical right ventricular electrode and an additional left ventricular electrode, which is floated into the coronary vein sinus. The non-responder rate of the CRT therapy is about one third of the CRT patients. His- Bundle-Pacing represents a physiological alternative to conventional cardiac pacing and cardiac resynchronization. An electrode implanted in the His-bundle emits a stronger electrical pacing field than the electrical pacing field of conventional cardiac pacemakers. The pacing of the Hisbundle was performed by the Medtronic Select Secure 3830 electrode with pacing voltage amplitudes of 3 V, 2 V and 1,5 V in combination with a pacing pulse duration of 1 ms. Compared to conventional pacemaker pacing, His-bundle pacing is capable of bridging LBBB conduction disorders in the left ventricle. The His-bundle pacing electrical field is able to spread via the physiological pathway in the right and left ventricles for CRT with a narrow QRS-complex in the surface ECG.
Bei bimodaler Cochlea-Implantat-/Hörgerät-Versorgung kann es aufgrund seitenverschiedener Signalverarbeitung zu einer zeitlich versetzten Stimulation der beiden Modalitäten kommen. Jüngste Studien haben gezeigt, dass durch zeitlichen Abgleich der Modalitäten die Schalllokalisation bei bimodaler Versorgung verbessert werden kann. Um solch einen Abgleich vornehmen zu können, ist die messtechnische Bestimmung der Durchlaufzeit von Hörgeräten erforderlich. Kommerziell verfügbare Hörgerätemessboxen können diese Werte häufig liefern. Die dazu verwendete Signalverarbeitung wird dabei aber oft nicht vollständig offengelegt. In dieser Arbeit wird ein alternativer und nachvollziehbarer Ansatz zum Design eines simplen Messaufbaus basierend auf einem Arduino DUE Mikrocontroller-Board vorgestellt. Hierzu wurde ein Messtisch im 3D-Druck gefertigt, auf welchem Hörgeräte über einen 2-ccm-Kuppler an ein Messmikrofon angeschlossen werden können. Über einen Latenzvergleich mit dem simultan erfassten Signal eines Referenzmikrofons kann die Durchlaufzeit von Hörgeräten bestimmt werden. Frequenzspezifische Durchlaufzeiten werden mittels einer Kreuzkorrelation zwischen Ziel- und Referenzsignal errechnet. Aufnahme, Ausgabe und Speicherung der Signale erfolgt über einen ATMEL SAM3X8E Mikrocontroller, welcher auf dem Arduino DUE-Board verbaut ist. Über eigens entworfene elektronische Schaltungen werden die Mikrofone und der verwendete Lautsprecher angesteuert. Nach Abschluss einer Messung (Messdauer ca. 5 s) werden die Messdaten seriell an einen PC übertragen, auf dem die Datenauswertung mittels MATLAB erfolgt. Erste Validierungen zeigten eine hohe Stabilität der Messergebnisse mit sehr geringen Standardabweichungen im Bereich weniger Mikrosekunden für Pegel zwischen 50 und 75 dB (A). Der Messaufbau wird in laufenden Studien zur Quantifizierung der Durchlaufzeit von Hörgeräten verwendet.
Dieses Buch erklärt, wie Führungskräfte reflektiert und verantwortungsvoll mit ihrer Macht umgehen können, und zeigt die Zusammenhänge zwischen Gestaltungsfeldern der Macht und Führungserfolg auf. Denn Macht ist eine entscheidende Größe, um innerhalb von sozialen Systemen Veränderungen durchzusetzen und Entwicklungen voranzutreiben oder gar erst zu ermöglichen.
Gerade in Unternehmen ist der bewusste und konstruktive Umgang mit Macht oft einer der Erfolgsfaktoren für Entscheider und Führungskräfte. Sie kann dabei nur durch die Menschen ausgeübt werden, denen sie durch andere zugesprochen oder auch zugebilligt wird. Deshalb kommt dem Verständnis von Macht eine entscheidende Bedeutung zu.
Der Autor beschreibt neben den Grundlagen 20 konkrete Anwendungsfelder im Arbeitsalltag von Führungskräften, ergänzt durch Beispiele, Checklisten und Handlungsempfehlungen.
Experimental Investigation of the Air Exchange Effectiveness of Push-Pull Ventilation Devices
(2020)
The increasing installation numbers of ventilation units in residential buildings are driven by legal objectives to improve their energy efficiency. The dimensioning of a ventilation system for nearly zero energy buildings is usually based on the air flow rate desired by the clients or requested by technical regulations. However, this does not necessarily lead to a system actually able to renew the air volume of the living space effectively. In recent years decentralised systems with an alternating operation mode and fairly good energy efficiencies entered the market and following question was raised: “Does this operation mode allow an efficient air renewal?” This question can be answered experimentally by performing a tracer gas analysis. In the presented study, a total of 15 preliminary tests are carried out in a climatic chamber representing a single room equipped with two push-pull devices. The tests include summer, winter and isothermal supply air conditions since this parameter variation is missing till now for push-pull devices. Further investigations are dedicated to the effect of thermal convection due to human heat dissipation on the room air flow. In dependence on these boundary conditions, the determined air exchange efficiency varies, lagging behind the expected range 0.5 < εa < 1 in almost all cases, indicating insufficient air exchange including short-circuiting. Local air exchange values suggest inhomogeneous air renewal depending on the distance to the indoor apertures as well as the temperature gradients between in- and outdoor. The tested measurement set-up is applicable for field measurements.
The precise positioning of mobile systems is a prerequisite for any autonomous behavior, in an industrial environment as well as for field robotics. The paper describes the set up for an experimental platform and its use for the evaluation of simultaneous localization and mapping (SLAM) algorithms. Two approaches are compared. First, a local method based on point cloud matching and integration of inertial measurement units is evaluated. Subsequent matching makes it possible to create a three-dimensional point cloud that can be used as a map in subsequent runs. The second approach is a full SLAM algorithm, based on graph relaxation models, incorporating the full sensor suite of odometry, inertial sensors, and 3D laser scan data.
Nowadays, the wide majority of Europeans uses smartphones. However, touch displays are still not accessible by everyone. Individuals with deafblindness, for example, often face difculties in accessing vision-based touchscreens. Moreover, they typically have few fnancial resources which increases the need for customizable, low-cost assistive devices. In this work-in-progress, we present four prototypes made from low-cost, every-day materials, that make modern pattern lock mechanisms more accessible to individuals with vision impairments or even with deafblindness. Two out of four prototypes turned out to be functional tactile overlays for accessing digital 4-by-4 grids that are regularly used to encode dynamic dot patterns. In future work, we will conduct a user study investigating whether these two prototypes can make dot-based pattern lock mechanisms more accessible for individuals with visual impairments or deafblindness.
This work compares the performance of Bluetooth Mesh implementations on real chipsets against the ideal implementation of the specification. Measurements are taken in experimental settings and reveal non-idealities in the underlying Bluetooth Low Energy specification in real chipsets and in the implementation of Mesh, which introduces an unruly transmission as well as reception behavior. These effects lead to an impact on transmission rate, reception rate, latency, as well as a more significant impact on the average power consumption.
Extracting horizon surfaces from key reflections in a seismic image is an important step of the interpretation process. Interpreting a reflection surface in a geologically complex area is a difficult and time-consuming task, and it requires an understanding of the 3D subsurface geometry. Common methods to help automate the process are based on tracking waveforms in a local window around manual picks. Those approaches often fail when the wavelet character lacks lateral continuity or when reflections are truncated by faults. We have formulated horizon picking as a multiclass segmentation problem and solved it by supervised training of a 3D convolutional neural network. We design an efficient architecture to analyze the data over multiple scales while keeping memory and computational needs to a practical level. To allow for uncertainties in the exact location of the reflections, we use a probabilistic formulation to express the horizons position. By using a masked loss function, we give interpreters flexibility when picking the training data. Our method allows experts to interactively improve the results of the picking by fine training the network in the more complex areas. We also determine how our algorithm can be used to extend horizons to the prestack domain by following reflections across offsets planes, even in the presence of residual moveout. We validate our approach on two field data sets and show that it yields accurate results on nontrivial reflectivity while being trained from a workable amount of manually picked data. Initial training of the network takes approximately 1 h, and the fine training and prediction on a large seismic volume take a minute at most.
Oxide semiconductors have the potential to increase the performance of inkjet printed microelectronic devices such as field-effect transistors (FETs), due to their high electron mobilities. Typical metal oxides are n-type semiconductors, while p-type oxides, although realizable, exhibit lower carriermobilities. Therefore, the circuit design based on oxide semiconductors is mostly in n-type logic only. Here we present an inkjet printed pn-diode based on p- and n-type oxide semiconductors.Copper oxide or nickel oxide is used as p-typesemiconductor whereas n-typesemiconductor is realized with indium oxide. Themeasurements show that the pn-diodes operate in the voltage window typical for printed electronics and the emission coefficient is 1.505 and 2.199 for the copper oxide based and nickel oxidebased pn-diode, respectively.Furthermore, a pn-diode model is developed and integrable into a circuit simulator.
Amorphous In-Ga-Zn-O (IGZO) is a high-mobility semiconductor employed in modern thin-film transistors for displays and it is considered as a promising material for Schottky diode-based rectifiers. Properties of the electronic components based on IGZO strongly depend on the manufacturing parameters such as the oxygen partial pressure during IGZO sputtering and post-deposition thermal annealing. In this study, we investigate the combined effect of sputtering conditions of amorphous IGZO (In:Ga:Zn=1:1:1) and post-deposition thermal annealing on the properties of vertical thin-film Pt-IGZO-Cu Schottky diodes, and evaluated the applicability of the fabricated Schottky diodes for low-frequency half-wave rectifier circuits. The change of the oxygen content in the gas mixture from 1.64% to 6.25%, and post-deposition annealing is shown to increase the current rectification ratio from 10 5 to 10 7 at ±1 V, Schottky barrier height from 0.64 eV to 0.75 eV, and the ideality factor from 1.11 to 1.39. Half-wave rectifier circuits based on the fabricated Schottky diodes were simulated using parameters extracted from measured current-voltage and capacitance-voltage characteristics. The half-wave rectifier circuits were realized at 100 kHz and 300 kHz on as-fabricated Schottky diodes with active area of 200 μm × 200 μm, which is relevant for the near-field communication (125 kHz - 134 kHz), and provided the output voltage amplitude of 0.87 V for 2 V supply voltage. The simulation results matched with the measurement data, verifying the model accuracy for circuit level simulation.
In der Forschungsgruppe um Prof. Dr. Thomas Wendt werden Themen in unterschiedlichsten Bereichen von Automatisierungstechnik über funktionale Sicherheit bis hin zur 3D-gedruckten Elektronik / Sensorik behandelt. Insgesamt arbeiten vier Doktoranden und vier Mitarbeiter an der Weiterentwicklung der verschiedenen Technologien, die in diesem Artikel zusammengefasst dargestellt sind.
Fully Printed Inverters using Metal‐Oxide Semiconductor and Graphene Passives on Flexible Substrates
(2020)
Printed and flexible metal‐oxide transistor technology has recently demonstrated great promise due to its high performance and robust mechanical stability. Herein, fully printed inverter structures using electrolyte‐gated oxide transistors on a flexible polyimide (PI) substrate are discussed in detail. Conductive graphene ink is printed as the passive structures and interconnects. The additive printed transistors on PI substrates show an on/off ratio of 106 and show mobilities similar to the state‐of‐the‐art printed transistors on rigid substrates. Printed meander structures of graphene are used as pull‐up resistances in a transistor–resistor logic to create fully printed inverters. The printed and flexible inverters show a signal gain of 3.5 and a propagation delay of 30 ms. These printed inverters are able to withstand a tensile strain of 1.5% following more than 200 cycles of mechanical bending. The stability of the electrical direct current (DC) properties has been observed over a period of 5 weeks. These oxide transistor‐based fully printed inverters are relevant for digital printing methods which could be implemented into roll‐to‐roll processes.
Fusion 360 – kurz und bündig
(2020)
Dieses Lehrbuch ermöglicht dem Anfänger in der 3D-Modellierung einen schnellen Einstieg in die Arbeit mit dem cloudbasierten CAD-System Autodesk® Fusion 360TM. Der Schwerpunkt liegt dabei auf den grundlegenden Funktionen zur Modellierung von Einzelteilen und dem Zusammenbau von Produkten, sowie in der Erstellung von einfachen technischen Zeichnungen. Dabei werden bei jedem Schritt die besonderen Anforderungen an eine 3D-Druck-gerechte Gestaltung erläutert und umgesetzt. Somit ist das Ergebnis dieser „Schritt für Schritt“-Anleitung die vollständige Modellierung eines Miniatur-Automobils, das am 3D-Drucker in ein reales Modell umgesetzt werden kann. Das didaktische Konzept ist so ausgelegt, dass alle Schritte für ein Selbststudium geeignet sind. Die vorliegende Auflage wurde komplett überarbeitet, sie basiert auf der neuen Benutzeroberfläche User Interface (UI) und enthält ein neues Kapitel zum CNC-Blechbiegen.
Gasdynamik
(2020)
Für kompressible Strömungen werden die Erhaltungssätze für Masse, Impuls und Energie hergeleitet. Die Eigenschaften der Stoßgleichungen wie Rankine-Hugoniot-Relation und Rayleigh-Gerade werden betrachtet. Zur Berechnung der Kräfte auf umströmte Körper werden die Auftriebs- und Widerstandsbeiwerte ermittelt. Auf der Basis der Stromfadentheorie wird die Auslegung von Lavaldüsen behandelt. Das physikalische Verhalten linearer Unter- und Überschallströmungen und transsonischer Profilumströmungen wird analysiert.
Die Coronakrise hat weltweit das Wirtschafts- und Gesellschaftsleben in bisher ungekannter Weise verändert. Die ohnehin bereits komplexen Herausforderungen in Zeiten des Klimawandels sind damit noch gestiegen. Genossenschaftliche Innovationsökosysteme können Lösungsansätze für die gravierenden Veränderungen im unternehmerischen, kommunalen und gesellschaftlichen Umfeld schaffen.
In dem durchgeführten Verbundvorhaben arbeiteten zum einen die Fachgebiete Geologie/Geothermie sowie Anlagen- und Systemtechnik von geothermischer Kältegewinnung und Kältenutzung der Projektpartner interdisziplinär zusammen, um den aktuellen Wissensstand der Kühlung mittels oberflächennaher Geothermie fachübergreifend zu erfassen, zu bewerten und Schnittstellenprobleme zu bearbeiten. Aus dieser interdisziplinären Betrachtungsweise wurden ganzheitliche Hinweise zur Optimierung des geothermischen Kühlpotenzials sowie Anstöße für technische und planerische Innovationen für die Praxis entwickelt und in diese transferiert.
Zu folgenden Zielen wurden Beiträge erarbeitet:
- Steigerung der Energieeffizienz der Kühlung und Kältebereitstellung
- Nutzung regenerativer Energien zur Kühlung und Kältebereitstellung
- Begrenzung der thermischen Belastung des Untergrunds und des Grundwassers
- Minimierung der Schäden und Risiken durch den Eingriff in den Untergrund
In this entry, the 3D CAD reconstructions and 3D multi-material polymer replica printings of knight Götz von Berlichingen´s first „Iron Hand,“ which were developed in the last few years at Offenburg University, are presented. Even by today's standards, the first “Iron Hand”–as could be shown in the replicas–demonstrates sophisticated mechanics and well thought-out functionality and still offers inspiration and food for discussion when it comes to the question of an artificial prosthetic replacement for a hand.
Restoring hand motion to people experiencing amputation, paralysis, and stroke is a critical area of research and development. While electrode-based systems that use input from the brain or muscle have proven successful, these systems tend to be expensive and di¨cult to learn. One group of researchers is exploring the use of augmented reality (AR) as a new way of controlling hand prostheses. A camera mounted on eyeglasses tracks LEDs on a prosthetic to execute opening and closing commands using one of two different AR systems. One system uses a rectangular command window to control motion: crossing horizontally signals “open” along one direction and “close” in the opposite direction. The second system uses a circular command window: once control is enabled, gripping strength can be controlled by the direction of head motion. While the visual system remains to be tested with patients, its low cost, ease of use, and lack of electrodes make the device a promising solution for restoring hand motion.
Die wichtigste Erfahrung beim Zeichnen ist der Prozess, mit einem Stift Spuren und Zeichen zu setzen, die direkt beim Zeichnen entstehen. Ob mit Stift auf Papier, mit dem Finger oder einem Stock im Sand: Man lässt sich auf diesen Prozess des Entstehens ein. Es ist ein Wechselspiel von Auge und Hand, mal gewollt und kontrolliert, ein anderes Mal als Spiel aus Neugier, Intuition und Zufall. Wenn es gelingt, den Alltag auszuschließen, ist Zeichnen wie Musizieren oder Tanzen, ein Akt der Poiesis, das Hervorbringen von Werken im autotelischen Zustand. Handeln und Sein ist als Qualität und Erkenntnisform eins oder neudeutsch: Ich bin im Flow.
Novel manufacturing technologies, such as printed electronics, may enable future applications for the Internet of Everything like large-area sensor devices, disposable security, and identification tags. Printed physically unclonable functions (PUFs) are promising candidates to be embedded as hardware security keys into lightweight identification devices. We investigate hybrid PUFs based on a printed PUF core. The statistics on the intra- and inter-hamming distance distributions indicate a performance suitable for identification purposes. Our evaluations are based on statistical simulations of the PUF core circuit and the thereof generated challenge-response pairs. The analysis shows that hardware-intrinsic security features can be realized with printed lightweight devices.
Wer sich als Pädagoge und Wissenschaftler mit dem Thema Digitalisierung im Kontext von Unterricht, Lehre und Bildungsprozessen befasst, stellt schnell fest: Kaum jemand realisiert die Tragweite der durch Digitaltechnik und Netzwerke möglichen und von IT-Konzernen forcierten Transformation von Bildungseinrichtungen zu immer stärker automatisierten, kybernetisch gesteuerten Beschulungs- und Prüfanstalten. „It’s the economy, stupid“ wird zum Mantra auch der Bildung. Der Begriff Learning Analytics als Teilaspekt von Big Data Analytics weist ebenso auf Automatisierungstechnik für Lernprozesse wie der Begriff der datengestützten Schulentwicklung (Hartong, Learning Analytics und Big data in der Bildung, 2019). Mit Summit Learning (Facebook), Google Classroom oder Apple Education sind vollautomatisierte Systeme in den USA bereits im Einsatz. Der DigitalPakt Schule schafft die technischen Voraussetzungen für die Beschulung per Netz und Cloud in Deutschland (Lankau, Bildungsmarkt Schule. Tatsächliche Kosten des Digitalpakt Schule und verdeckte Interessen, 2019a).
Wireless synchronization of industrial controllers is a challenging task in environments where wired solutions are not practical. The best solutions proposed so far to solve this problem require pretty expensive and highly specialized FPGA-based devices. With this work we counter the trend by introducing a straightforward approach to synchronize a fairly cheap IEEE 802.11 integrated wireless chip (IWC) with external devices. More specifically we demonstrate how we can reprogram the software running in the 802.11 IWC of the Raspberry Pi 3B and transform the receiver input potential of the wireless transceiver into a triggering signal for an external inexpensive FPGA. Experimental results show a mean-square synchronization error of less than 496 ns, while the absolute synchronization error does not exceed 6 μs. The jitter of the output signal that we obtain after synchronizing the clock of the external device did not exceed 5.2 μs throughout the whole measurement campaign. Even though we do not score new records in term of accuracy, we do in terms of complexity, cost, and availability of the required components: all these factors make the proposed technique a very promising of the deployment of large-scale low-cost automation solutions.
High-performance Ag–Se-based n-type printed thermoelectric (TE) materials suitable for room-temperature applications have been developed through a new and facile synthesis approach. A high magnitude of the Seebeck coefficient up to 220 μV K–1 and a TE power factor larger than 500 μW m–1 K–2 for an n-type printed film are achieved. A high figure-of-merit ZT ∼0.6 for a printed material has been found in the film with a low in-plane thermal conductivity κF of ∼0.30 W m–1 K–1. Using this material for n-type legs, a flexible folded TE generator (flexTEG) of 13 thermocouples has been fabricated. The open-circuit voltage of the flexTEG for temperature differences of ΔT = 30 and 110 K is found to be 71.1 and 181.4 mV, respectively. Consequently, very high maximum output power densities pmax of 6.6 and 321 μW cm–2 are estimated for the temperature difference of ΔT = 30 K and ΔT = 110 K, respectively. The flexTEG has been demonstrated by wearing it on the lower wrist, which resulted in an output voltage of ∼72.2 mV for ΔT ≈ 30 K. Our results pave the way for widespread use in wearable devices.
The development of Internet of Things (IoT) embedded devices is proliferating, especially in the smart home automation system. However, the devices unfortunately are imposing overhead on the IoT network. Thus, the Internet Engineering Task Force (IETF) have introduced the IPv6 Low-Power Wireless Personal Area Network (6LoWPAN) to provide a solution to this constraint. 6LoWPAN is an Internet Protocol (IP) based communication where it allows each device to connect to the Internet directly. As a result, the power consumption is reduced. However, the limitation of data transmission frame size of the IPv6 Routing Protocol for Low-power and Lossy Network’s (RPL’s) had made it to be the running overhead, and thus consequently degrades the performance of the network in terms of Quality of Service (QoS), especially in a large network. Therefore, HRPL was developed to enhance the RPL protocol to minimize redundant retransmission that causes the routing overhead. We introduced the T-Cut Off Delay to set the limit of the delay and the H field to respond to actions taken within the T-Cut Off Delay. Thus, this paper presents the comparison performance assessment of HRPL between simulation and real-world scenarios (6LoWPAN Smart Home System (6LoSH) testbed) in validating the HRPL functionalities. Our results show that HRPL had successfully reduced the routing overhead when implemented in 6LoSH. The observed Control Traffic Overhead (CTO) packet difference between each experiment is 7.1%, and the convergence time is 9.3%. Further research is recommended to be conducted for these metrics: latency, Packet Delivery Ratio (PDR), and throughput.