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Controlling ist ein Begriff aus der Wirtschaftslehre und bezeichnet nicht Kontrollle, sondern Prozeßsteuerung. Definierte Ziele werden durch kleinteilige Messungen und permanente Überwachung aller Arbeitsschritte und Handlungen der beteiligten Personen protokolliert und stetig optimiert. Dieses Konzept der Planungs-, Koordinations- und Kontrollaufgaben wird beim „Bildungs-Controlling“ auf Schulen und Hochschulen übertragen. Ziel ist dabei, entsprechend der Gary Beckerschen Humankapitaltheorie, die Produktion von Humankapital mit validierten Kompetenzen. Zwei Probleme gibt es dabei: Lernen und vor allem Verstehen lassen sich nicht automatisieren und auch nicht automatisiert prüfen. Und: Sozialsysteme unter dem Regime der Kennzahlen des Quality Management (QM) oder Total Quality Management (TQM) verlieren ihre Eigenschaft als soziale Systeme
Background: Transesophageal left atrial (LA) pacing and transesophageal LA ECG recording are semi-invasive techniques for diagnostic and therapy of supraventricular rhythm disturbance. Cardiac resynchronization therapy (CRT) with right atrial (RA) sensed biventricular pacing is an established therapy for heart failure patients with reduced left ventricular (LV) ejection fraction, sinus rhythm and interventricular electrical desynchronization.
Purpose: The aim of the study was to evaluate electromagnetic and voltage pacing fields of the combination of RA pacing, LA pacing and biventricular pacing in patients with long interatrial and interventricular electrical desynchronization.
Methods: The modelling and electromagnetic simulations of transesophageal LA pacing in combination with RA pacing and biventricular pacing would be staged and analyzed with the CST (Computer Simulation Technology) software. Different electrodes were modelled in order to simulate different types of bipolar pacing in the 3D-CAD Offenburg heart rhythm model: The bipolar Solid S (Biotronik) electrode where modelled for RA pacing and right ventricular (RV) pacing, Attain 4194 (Medtronic) for LV pacing and TO8 (Osypka) multipolar esophageal electrode with hemispheric electrodes for LA pacing.
Results: The pacemaker amplitudes for the electromagnetic pacing simulations were performed with 3 V for RA pacing, 1.5 V for RV pacing, 50 V for LA pacing and 3V for LV pacing with pacing impulse duration of 0.5 ms for RA, RV and LV pacing and 10 ms for LA pacing. The atrioventricular pacing delay after RA pacing was 140 ms. The different pacing modes AAI, VVI, DDD, DDD0V and DDD0D were evaluated for the analysis of the electric pacing field propagation of pacemaker, CRT and LA pacing. The pacing results were compared at minimum (LOW) and maximum (HIGH) parameter settings. While the LOW setting produced fewer tetrahedral and more inaccurate results, the HIGH setting produced many tetrahedral and therefore more accurate results.
Conclusions: The simulation of the combination of transesophageal LA pacing with RA sensed biventricular pacing is possible with the Offenburg heart rhythm model. The new temporary 4-chamber pacing method may be additional useful method in CRT non-responders with long interatrial electrical delay.
As part of the design education at Offenburg University, the teaching in technical documentation is continuously optimised. In this study, numerous mechanical engineering students, ages 19 to 29, are observed using the eye tracking technology and a video camera while performing various design exercises. The aim of the study is to enhance the students’ ability to read, understand and analyse complex engineering drawings. In one experiment, the students are asked to perform the “cube perspective test” after Stumpf and Fay to assess their ability for mental rotation as part of spatial visualization ability. Furthermore, the students are asked to prepare and give micro presentations on a topic related to their studies. Students have a maximum of 100 s time for these presentations. Thus, they can practise presenting important information in a short amount of time, show their rhetorical skills and demonstrate their acquisition of basic knowledge. During the presentation, the eye movement of a few selected students is recorded to analyse their information acquisition. In a further test, the students’ eye movements are analysed while reading an engineering drawing that consists of multiple views. All the spatial connections have to be included based on the different component views. Including these and their acquired knowledge, the students are asked to identify the correct representation of a component view. Furthermore the subjects are describing the function of an assembly, a parallel gripper and then they are to mentally disassemble the assembly to replace a damaged cylindrical pin. Simultaneously, they are filmed using a video camera to see which terms the students use for the individual technical terms. The evaluation of the eye movements shows that the increasing digitalisation of society and the use of electronic devices in everyday life lead to fast and only selective perceptual behaviour and that students feel insecure when dealing with technical drawings. The analysis of the videos shows a mostly non-technical and inaccurate manner of expression and a poor use of technical terms. The transferability of the achieved results to other technical tasks is part of further investigations.
We present a novel approach that utilizes BLE packets sent from generic BLE capable radios to synthesize an FSK-(like) addressable wake-up packet. A wake-up receiver system was developed from off-the-shelf components to detect these packets. It makes use of two differential signal paths separated by passive band-pass filters. After the rectification of each channel a differential amplifier compares the signals and the resulting wake-up signal is evaluated by an AS3933 wake-up receiver IC. Overall, the combination of these techniques contributes to a BLE compatible wake-up system which is more robust than traditional OOK wake-up systems. Thus, increasing wake-up range, while still maintaining a low energy budget. The proof-of-concept setup achieved a sensitivity of -47.8 dBm at a power consumption of 18.5 uW during passive listening. The system has a latency of 31.8 ms with a symbol rate of 1437 Baud.
Es wird eine Fallstudie vorgestellt, die die Visualisierung von Geschäftsdaten nach dem International Business Communication Standard IBCS (Hichert & Faisst 2016 / 2017) auf der cloudbasierten Plattform SAP Analytics Cloud umsetzt. Mit der Fallstudie soll die Frage beantwortet werden, ob IBCS im Rahmen einer Lehreinheit mit hohem praktischem Anteil mit SAP Analytics Cloud umgesetzt werden kann. Darüber hinaus soll der generelle Einsatz von SAP Analytics Cloud für die Lehre im Analytics-Umfeld evaluiert werden.
Sweaty has already participated four times in RoboCup soccer competitions (Adult Size) and came second three times. While 2016 Sweaty needed a lot of luck to be finalist, 2017 Sweaty was a serious adversary in the preliminary rounds. In 2018 Sweaty showed up in the final with some lack of experience and room for improvements, but not without any chance. This paper describes the intended improvements of the humanoid adult size robot Sweaty in order to qualify for the RoboCup 2019 adult size competition.
Growing demands for cleaner production and higher eco-efficiency in process engineering require a comprehensive analysis of technical and environmental outcomes of customers and society. Moreover, unexpected additional technical or ecological drawbacks may appear as negative side effects of new environ-mentally friendly technologies. The paper conceptualizes a comprehensive ap-proach for analysis and ranking of engineering and ecological requirements in process engineering in order to anticipate secondary problems in eco-design and to avoid compromising the environmental or technological goals. For this purpose, the paper presents a method based on integration of the Quality Func-tion Deployment approach with the Importance-Satisfaction Analysis for the requirements ranking. The proposed method identifies and classifies compre-hensively the potential engineering and eco-engineering contradictions through analysis of correlations within requirements groups such as stakehold-er requirements (SRs) and technical requirements (TRs), and additionally through cross-relationship between SRs and TRs.
The development of new processes and materials for additive manufacturing is currently progressing rapidly. In order to use the advantages of additive manufacturing, however, product development and design must also be adapted to these new processes. Therefore it is suitable to use structural optimization. To achieve the best results in lightweight design, it is important to have an approach that reduces the volume in the unloaded regions and considers the restrictions and characteristics of the additive manufacturing process. In this contribution, a case study using a humanoid robot is presented. Thus, the pelvis module of a humanoid robot is optimized regarding its weight and stiffness. Furthermore, an integrated design is implemented in order to reduce the number of parts and the screw connections. The manufacturing uses a new aluminum-based material that has been specially developed for use in additive manufacturing and lightweight construction. For the additive manufacturing by means of the Selective Laser Melting (SLM) process, different restrictions and the assembly concepts of the humanoid robot have to be taken into account. These restrictions have to be considered in the setting of the individual parameters and target functions of the structural optimization. As a result, a framework is presented that shows the steps of the redesign and the optimization of the pelvis module. In order to achieve high accuracy with the product, the redesign of the pelvis module is demonstrated with regard to mechanical and thermal postprocessing. Finally, the redesigned part and the different assembly concepts are compared to analyze the economic and technical effects of the optimization.
Industrie 4.0 bedeutet nicht nur einen Wandel der technischen Möglichkeiten und Arbeitsbedingungen, sondern auch einen Bedarf an neuen, sich kontinuierlich weiterentwickelnden Kompetenzen und die Bereitschaft der Beschäftigten, Veränderungen mitzugestalten. Spielerische Ansätze der Kompetenzentwicklung können v.a. bei weiterbildungsfernen Mitarbeitern hilfreich sein, um das komplexe Thema verständlich zu vermitteln. Der Beitrag beschreibt ein Seminarkonzept mit integriertem Brettspiel, mit dem Teilnehmer anhand eines fiktiven Unternehmens (Müller GmbH) die Transformation eines Unternehmens in die Industrie 4.0 spielerisch nachvollziehen. Dieses Konzept erweist sich in einer ersten Evaluation als durchaus vielversprechend.
Avoiding collisions between a robot arm and any obstacle in its path is essential to human-robot collaboration. Multiple systems are available that can detect obstacles in the robot's way prior and subsequent to a collision. The systems work well in different areas surrounding the robot. One area that is difficult to handle is the area that is hidden by the robot arm. This paper focuses on pick and place maneuvers, especially on obstacle detection in between the robot arm and the table that robot is located on. It introduces the use of single pixel time-of-flight sensors to detect obstacles directly from the robot arm. The proposed approach reduces the complexity of the problem by locking axes of the robot that are not needed for the pick and place movement. The comparison of simulated results and laboratory measurements show concordance.
Most machine learning methods require careful selection of hyper-parameters in order to train a high performing model with good generalization abilities. Hence, several automatic selection algorithms have been introduced to overcome tedious manual (try and error) tuning of these parameters. Due to its very high sample efficiency, Bayesian Optimization over a Gaussian Processes modeling of the parameter space has become the method of choice. Unfortunately, this approach suffers from a cubic compute complexity due to underlying Cholesky factorization, which makes it very hard to be scaled beyond a small number of sampling steps. In this paper, we present a novel, highly accurate approximation of the underlying Gaussian Process. Reducing its computational complexity from cubic to quadratic allows an efficient strong scaling of Bayesian Optimization while outperforming the previous approach regarding optimization accuracy. First experiments show speedups of a factor of 162 in single node and further speed up by a factor of 5 in a parallel environment.
This work discusses several use cases of post-mortem mobile device tracking in which privacy is required e.g. due to client-confidentiality agreements and sensibility of data from government agencies as well as mobile telecommunication providers. We argue that our proposed Bloomfilter based privacy approach is a valuable technical building block for the arising General Data Protection Regulation (GDPR) requirements in this area. In short, we apply a solution based on the Bloom filters data structure that allows a 3rd party to performsome privacy saving setrelations on a mobiletelco’s access logfile or other mobile access logfile from harvesting parties without revealing any other mobile users in the proximity of a mobile base station but still allowing to track perpetrators.
For e-commerce retailers it is crucial to present their products both informatively and attractively. Virtual reality (VR) systems represent a new marketing tool that supports customers in their decision-making process and offers an extraordinary product experience. Despite these advantages, the use of this technology for e-commerce retailers is also associated with risks, namely cybersickness. The aim of the study is to investigate the occurrence of cybersickness in the context of the customer’s perceived enjoyment and the perceived challenge of a VR product presentation. Based on a conceptual research framework, a laboratory study with 533 participants was conducted to determine the influence of these factors on the occurrence of cybersickness. The results demonstrate that the perceived challenge has a substantially stronger impact on the occurrence of cybersickness, which can only be partially reduced by perceived enjoyment. When realizing VR applications in general and VR product presentations in particular, e-commerce retailers should therefore first minimize possible challenges instead of focusing primarily on entertainment aspects of such applications.
Printed Electronics is perceived to have a major impact in the fields of smart sensors, Internet of Things and wearables. Especially low power printed technologies such as electrolyte gated field effect transistors (EGFETs) using solution-processed inorganic materials and inkjet printing are very promising in such application domains. In this paper, we discuss a modeling approach to describe the variations of printed devices. Incorporating these models and design flows into our previously developed printed design system allows for robust circuit design. Additionally, we propose a reliability-aware routing solution for printed electronics technology based on the technology constraints in printing crossovers. The proposed methodology was validated on multiple benchmark circuits and can be easily integrated with the design automation tools-set.
Die Vorlesung Physik ist ein grundlegender Baustein der meisten Ingenieursstudiengänge und stellt für viele Studienanfänger eine Hürde zum Studienstart da. Die Vorkenntnisse der Studienanfänger sind zunehmend heterogen und der sichere Umgang mit physikalischen Konzepten erfordert mehr oder wenig Übung, um diese zu festigen oder auch erstmals einzuführen. Um dieses Üben zu ermöglichen, wurde für die Vorlesung "Physik 1" in den Studiengängen Maschinenbau, Werkstofftechnik, Mechatronik, Biomechanik, Biotechnologie und Umwelt- und Verfahrenstechnik der Hochschule Offenburg ein E-Tutorium erarbeitet, das die Übungsaufgaben in Form von 10 Online-Selbsttest mit jeweils vier Übungsaufgaben anbietet. Die Selbsttests beinhalten dabei typische Aufgabenstellungen, deren Zahlenwerte (Masse, Geschwindigkeit usw.) bei jedem Aufruf der Aufgabe variieren. Dadurch lassen sich die Selbsttests zum selbständigen Üben nutzen. Ein reines Abschreiben einer Musterlösung ist durch die veränderlichen Zahlenwerte darüber hinaus unmöglich. Wir beschreiben eine Methode zur effizienten Erzeugung der Moodle-basierten Selbsttests mit Hilfe der Software R/exams und berichten über die Erfahrungen beim ersten Einsatz.
Narrowband IoT (NB-IoT) as a radio access technology for the cellular Internet of Things (cIoT) is getting more traction due to attractive system parameters, new proposals in the 3 rd Generation Partnership Project (3GPP) Release 14 for reduced power consumption and ongoing world-wide deployment. As per 3GPP, the low-power and wide-area use cases in 5G specification will be addressed by the early NB-IoT and Long-Term Evolution for Machines (LTE-M) based technologies. Since these cIoT networks will operate in a spatially distributed environment, there are various challenges to be addressed for tests and measurements of these networks. To meet these requirements, unified emulated and field testbeds for NB-IoT-networks were developed and used for extensive performance measurements. This paper analyses the results of these measurements with regard to RF coverage, signal quality, latency, and protocol consistency.
Low latency communication is essential to enable mission-critical machine-type communication (mMTC) use cases in cellular networks. Factory and process automation are major areas that require such low latency communication. In this paper, we investigate the potential of adopting the semi-persistent scheduling (SPS) latency reduction technique in narrowband LTE (NB-LTE) networks and provide a comprehensive performance evaluation. First, we investigate and implement SPS in an open-source network simulator (NS3). We perform simulations with a focus on LTE-M and Narrowband IoT (NB-IoT) systems and evaluate the impact of the SPS technique on the uplink latency of these narrowband systems in real industrial automation scenarios. The performance gain of adopting SPS is analyzed and the results is compared with the legacy dynamic scheduling. Our results show that SPS has the potential to reduce the latency of cellular Internet of Things (cIoT) networks. We believe that SPS can be integrated into LTE-M and NB-IoT systems to support low-latency industrial applications.
The high peak power in comparison to the average transmit power is one of the major long-standing problems in multicarrier modulation and is known as the PAPR (peak to average power ratio) problem. Many PAPR reduction methods have been devised and their comparison is usually based on the complementary cumulative distribution function (CCDF) of the PAPR. While this comparison is straightforward and easy to compute, its relationship with system performance metrics like the (uncoded) BER or the word error rate (WER) for coded systems is considerably more involved. We evaluate the impact of the PAPR on performance metrics like uncoded BER, EVM (error vector magnitude), mutual information and the WER for soft decoding. In this context, we find that system performance is not necessarily degraded by an increasing PAPR. We show that a high number of subcarriers, despite the corresponding high PAPR, is actually not a problem for the system performance and provide a simple explanation for this seemingly counter-intuitive fact.
Recent deep learning based approaches have shown remarkable success on object segmentation tasks. However, there is still room for further improvement. Inspired by generative adversarial networks, we present a generic end-to-end adversarial approach, which can be combined with a wide range of existing semantic segmentation networks to improve their segmentation performance. The key element of our method is to replace the commonly used binary adversarial loss with a high resolution pixel-wise loss. In addition, we train our generator employing stochastic weight averaging fashion, which further enhances the predicted output label maps leading to state-of-the-art results. We show, that this combination of pixel-wise adversarial training and weight averaging leads to significant and consistent gains in segmentation performance, compared to the baseline models.
One of the challenges for autonomous driving in general is to detect objects in the car's camera images. In the Audi Autonomous Driving Cup (AADC), among those objects are other cars, adult and child pedestrians and emergency vehicle lighting. We show that with recent deep learning networks we are able to detect these objects reliably on the limited Hardware of the model cars. Also, the same deep network is used to detect road features like mid lines, stop lines and even complete crossings. Best results are achieved using Faster R-CNN with Inception v2 showing an overall accuracy of 0.84 at 7 Hz.
A car is only useful, when it runs properly – but keeping a car it running is getting more and more complex. Car service providers need a deep knowledge about technical details of the different car models. On the other hand car producers try to keep this information in their ownership. Digital data collection takes place every second on the car´s product life cycle and is stored on the car producers´ servers. The contribution of this paper is three-fold: we will provide an overview of the current concepts of intelligent order assistant technologies (I). This corpus is used to come to a more precise description of the specific service performance aspects (II). Finally, a representative empirical study with German motor mechanics will help to evaluate the wishes and needs regarding an intelligent order assistant in the garage (III).
With the surge in global data consumption with proliferation of Internet of Things (IoT), remote monitoring and control is increasingly becoming popular with a wide range of applications from emergency response in remote regions to monitoring of environmental parameters. Mesh networks are being employed to alleviate a number of issues associated with single-hop communication such as low area coverage, reliability, range and high energy consumption. Low-power Wireless Personal Area Networks (LoWPANs) are being used to help realize and permeate the applicability of IoT. In this paper, we present the design and test of IEEE 802.15.4-compliant smart IoT nodes with multi-hop routing. We first discuss the features of the software stack and design choices in hardware that resulted in high RF output power and then present field test results of different baseline network topologies in both rural and urban settings to demonstrate the deployability and scalability of our solution.
Hintergrund: Die Pulmonalvenenisolation (PVI) mit Hilfe von Kryoballonkathetern ist eine anerkannte Methode zur Behandlung von Vorhofflimmern (AF). Diese Methode bietet eine kürzere Behandlungsdauer als die klassische Therapie durch die Hochfrequenzablation (HF). Ziel dieser Studie war es, verschiedene Kryoballonkatheter, HF-Katheter und Ösophaguskatheter in ein Herzrhythmusmodell zu integrieren und mittels statischer und dynamischer Simulation elektrische und thermische Felder bei PVI unter Vorhofflimmern zu untersuchen.
Methodik: Die Modellierung und Simulation erfolgte mit der elektromagnetischen und thermischen Simulationssoftware CST (CST Darmstadt). Zwei Kryoballons, ein HF-Ablationskatheter und ein Ösophaguskatheter wurden auf der Grundlage der technischen Handbücher der Hersteller Medtronic und Osypka modelliert. Der 23 mm Kryoballon und ein kreisförmiger Mappingkatheter wurden in das Offenburger Herzrhythmusmodell integriert, insbesondere die left inferior pulmonary vein (LIPV) zur Simulation der thermischen Feldausbreitung während einer PVI. Die Simulation einer PVI mit HF-Energie wurde mit dem integrierten HF-Ablationskatheter in der Nähe der LIPV durchgeführt. Der im Herzrhythmusmodell platzierte TO8 Ösophaguskatheter ermöglichte die Ableitung linksatrialer elektrischer Felder bei AF und die Analyse thermischer Felder während PVI.
Ergebnisse: Elektrische Felder konnten bei Sinusrhythmus und AF mit einem AF-Fokus in der LIVP statisch und dynamisch im Herzen und Ösophagus simuliert werden. Bei einer simulierten 20 Sekunden Applikation eines Kryoballon-Katheters bei -50°C wurde eine Temperatur von -24°C in einer Tiefe von 0,5 mm im Myokard gemessen. In einer Tiefe von 1 mm betrug die Temperatur -3°C, bei 2 mm Tiefe 18°C und bei 3 mm Tiefe 29°C. Unter der 15 sekündigen Anwendung eines HF-Katheters mit einer 8-mm-Elektrode und einer Leistung von 5 W bei 420 kHz betrug die Temperatur an der Spitze der Elektrode 110°C. In einer Tiefe von 0,5 mm im Myokard betrug die Temperatur 75°C, in einer Tiefe von 1 mm 58°C, in einer Tiefe von 2 mm 45°C und in einer Tiefe von 3 mm 38°C. Im Ösophagus konnte bei den meisten Simulationen eine konstante Temperatur von 37°C gemessen und die Gefahr einer Ösophagus-Fistel ausgeschlossen werden. Bei Kryoablation der LIPV wurde eine Abkühlung des Ösophagus auf 30°C gemessen.
Schlussfolgerungen: Die Herzrhythmussimulation elektrischer und thermaler Felder ermöglichen mit Anwendung unterschiedlicher Herzkatheter eine statische und dynamische Simulation von PVI durch Kryoablation, HF-Ablation und Temperaturanalyse im Ösophagus. Unter Einbeziehung von MRT- oder CT-Daten können elektrische und thermale Simulationen möglicherweise zur Optimierung von PVIs genutzt werden.
Model-based analysis of Electrochemical Pressure Impedance Spectroscopy (EPIS) for PEM Fuel Cells
(2019)
Electrochemical impedance spectroscopy (EIS) is a widely-used diagnostic technique to characterize electrochemical processes. It is based on the dynamic analysis of two electrical observables, that is, current and voltage. Electrochemical cells with gaseous reactants or products, in particular fuel cells, offer an additional observable, that is, the gas pressure. The dynamic coupling of current or voltage with gas pressure gives rise to a number of additional impedance definitions, for which we have previously introduced the term electrochemical pressure impedance spectroscopy (EPIS) [1,2]. EPIS shows a particular sensitivity towards transport processes of gas-phase or dissolved species, in particular, diffusion coefficients and transport pathway lengths. It is as such complementary to standard EIS, which is mainly sensitive towards electrochemical processes. First EPIS experiments on PEM fuel cells have recently been shown [3].
We present a detailed modeling and simulation analysis of EPIS of a PEM fuel cell. We use a 1D+1D continuum model of a fuel/air channel pair with GDL and MEA. Backpressure is dynamically varied, and the resulting simulated oscillation in cell voltage is evaluated to yield the ▁Z_( V⁄p_ca ) EPIS signal. Results are obtained for different transport situations of the fuel cell, giving rise to very complex EPIS shapes in the Nyquist plot. This complexity shows the necessity of model-based interpretation of the complex EPIS shapes. Based on the simulation results, specific features in the EPIS spectra can be assigned to different transport domains (gas channel, GDL, membrane water transport).
Amongst all the major hazard aspects for the health of people in big conglomerates is the increase of the particulate matter concentration. Traditional systems for particulate matter (PM) monitoring have a great number of drawbacks but the main issues are economical and are related to the installation costs and never ending periodical maintenance expenses. After all there are installations of such systems but their number is limited and having in mind the growth of population, cities and industry areas, there is even a bigger need for more information on air quality because PM changes non-linearly, has a wide range and different sources. In this paper, we propose an approach, based on low-cost sensor nodes, for real-time measuring and obtaining information about the PM concentration. The adoption of that approach allows for a detailed study of the intensities of pollution and its sources. The system power supply is powered by a PV module. The power supply unit is designed using a model-based design that is a new approach to prototyping power-operated electronic devices with guaranteed performance.
Die Studienanfänger in den technischen Studiengängen der Hochschulen für angewandte Wissenschaften haben nicht nur in Mathematik sondern auch in Physik sehr unterschiedliche Vorkenntnisse. Obwohl diese Fächer für das grundlegende Verständnis technischer Vorgänge von großer Bedeutung sind, kann die Ausbildung in diesen Bereichen angesichts der begrenzten dafür im Verlauf des Studiums zur Verfügung stehenden Zeitfenster nicht bei Null anfangen. Für Mathematik wurde daher von der Arbeitsgruppe cosh ein Mindestanforderungskatalog zusammengestellt und 2014 veröffentlicht. Er beschreibt Kenntnisse und Fertigkeiten, die Studienanfänger zur erfolgreichen Aufnahme eines WiMINT-Studiums (Wirtschaft, Mathematik, Informatik, Naturwissenschaft, Technik) an einer Hochschule benötigen. Inzwischen hat sich nun eine Arbeitsgruppe von Physikerinnen und Physikern an Hochschulen in Baden-Württemberg gebildet, deren Ziel es ist, einen analogen Mindestanforderungskatalog für den Bereich Physik zu erstellen. Hier wird der aktuell erreichte Stand der Arbeiten vorgestellt.
This paper describes the concept and some results of the project "Menschen Lernen Maschinelles Lernen" (Humans Learn Machine Learning, ML2) of the University of Applied Sciences Offenburg. It brings together students of different courses of study and practitioners from companies on the subject of Machine Learning. A mixture of blended learning and practical projects ensures a tight coupling of machine learning theory and application. The paper details the phases of ML2 and mentions two successful example projects.
The 40 Altshuller Inventive Principles with numerous sub-principles remain over decades the most frequently applied tool of the Theory of Inventive Problem Solving TRIZ for systematic idea generation. However, their application often requires a concentrated, creative and abstract way of thinking that can be fairly challenging for the newcomers to TRIZ. This paper describes an approach to reduce the abstraction level of inventive sub-principles and presents the results of the idea generation experiment conducted with three groups of undergraduate and graduate students from different years of study in mechanical and process engineering. The students were asked to generate and to record their individual ideas for three design problems using a pre-defined set of classical and modified sub-principles within 10 minutes. The overall outcomes of the experiment support the assumption that the less abstract wording of the modified sub-principles leads to higher number of ideas. The distribution of ideas between the fields of MATCHEM-IBD (Mechanical, Acoustic, Thermal, Chemical, Electrical, Magnetic, Intermolecular, Biological and Data processing) differs significantly between groups using modified and abstract sub-principles.
Die Möglichkeit zur digitalen Verbindung geographischer Orte mit Aufgaben, Herausforderungen oder Lernmaterialien hat eine Vielzahl von Anwendungen auch außerhalb der Mathematikbildung inspiriert. Dieser Beitrag stellt eine exemplarische Auswahl solcher Applikationen vor und versucht, die technischen, organisatorischen und konzeptionellen Gestaltungselemente zu systematisieren. Die Ausführungen sollen als Anregung bei der Anlage von Mathematiktrails sowie bei der Weiterentwicklung technischer Lösungen für den Lehreinsatz dienen.
Enabling ultra-low latency is one of the major drivers for the development of future cellular networks to support delay sensitive applications including factory automation, autonomous vehicles and tactile internet. Narrowband Internet of Things (NB-IoT) is a 3 rd Generation Partnership Project (3GPP) Release 13 standardized cellular network currently optimized for massive Machine Type Communication (mMTC). To reduce the latency in cellular networks, 3GPP has proposed some latency reduction techniques that include Semi Persistent Scheduling (SPS) and short Transmission Time Interval (sTTI). In this paper, we investigate the potential of adopting both techniques in NB-IoT networks and provide a comprehensive performance evaluation. We firstly analyze these techniques and then implement them in an open-source network simulator (NS3). Simulations are performed with a focus on Cat-NB1 User Equipment (UE) category to evaluate the uplink user-plane latency. Our results show that SPS and sTTI have the potential to greatly reduce the latency in NB-IoT systems. We believe that both techniques can be integrated into NB-IoT systems to position NB-IoT as a preferred technology for low data rate Ultra-Reliable Low-Latency Communication (URLLC) applications before 5G has been fully rolled out.
After the successful International Year of Light 2015, the idea of sustainability became increasingly imminent. After a preparatory year on 16 May 2018, the International Day of Light was launched for the first time. This event was celebrated with a public celebration in Paris at the UNESCO headquarters. In this paper we will present our projects dedicated to the International Day of Light in Paris. Together with a group of students from our university, we had the special opportunity to be integrated in the program of the opening ceremony at UNESCO in Paris. With our interdisciplinary projects we have tried to build a bridge between optics, photonics, art and media installations.
Blockchain frameworks enable the immutable storage of data. A still open practical question is the so called "oracle" problem, i.e. the way how real world data is actually transferred into and out of a blockchain while preserving its integrity. We present a case study that demonstrates how to use an existing industrial strength secure element for cryptographic software protection (Wibu CmDongle / the "dongle") to function as such a hardware-based oracle for the Hyperledger blockchain framework. Our scenario is that of a dentist having leased a 3D printer. This printer is initially supplied with an amount of x printing units. With each print action the local unit counter on the attached dongle is decreased and in parallel a unit counter is maintained in the Hyperledger-based blockchain. Once a threshold is met, the printer will stop working (by means of the cryptographically protected invocation of the local print method). The blockchain is configured in such a way that chaincode is executed to increase the units again automatically (and essentially trigger any payment processes). Once this has happened, the new unit counter value will be passed from the blockchain to the local dongle and thus allow for further execution of print jobs.
The additive manufacturing processes have developed significantly in recent years. Currently, new generative processes are coming onto the market. Likewise, the number of available materials that can be processed using additive processes is steadily increasing. Therefore, an important task is to integrate these new processes and materials into the university education of engineers. Due to the rapid change and the constant development in the field of additive manufacturing, a pure transfer of knowledge is not expedient, because this obsolete very quickly. Rather, the students should be enabled to use their skills in such a way that they can always handle new technologies and materials independently and meaningfully.
In this paper, therefore, a new course is developed in which the students largely independently work with additive manufacturing processes. For this purpose, teams of four to five students from different technical programs are formed. The teams have the task of developing and manufacturing a product using additive processes. The goal is to create a powerful product by taking into account the optimization of costs and use of resources.
As an example, the development and additive manufacturing of an ornithopter (aircraft that flies by flapping its wings) will be presented in this contribution. The students have to analyze and optimize the mechanics and aerodynamics of the aircraft. In addition, the rules for production-oriented design must be determined and applied. Further more, they should assess the costs and material consumption during development and production.
This contribution shows how the students have achieved the different learning outcomes. In addition, it becomes clear how the students independently acquired and applied their knowledge in development, design and additive manufacturing. Also, it will be demonstrated how much time the students spent on learning the different technologies.
Printed electronics (PE) is a fast growing technology with promising applications in wearables, smart sensors and smart cards since it provides mechanical flexibility, 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 PE circuits results in high intrinsic variation due to the random dispersion of the printed inks on the substrate, constructing a printed TRNG is challenging. In this paper, we exploit the additive customizable fabrication feature of inkjet printing to design a TRNG based on electrolyte-gated field effect transistors (EGFETs). The proposed memory-based TRNG circuit can operate at low voltages (≤ 1 V ), it is hence suitable for low-power applications. We also propose a flow which tunes the printed resistors of 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 behaviour. The results show that the overall process variation of the TRNGs is mitigated by 110 times, and the simulated TRNGs pass the National Institute of Standards and Technology Statistical Test Suite.
Increased knowledge transfer through the integration of research projects into university teaching
(2019)
This paper describes the integration of the research project "Characterization of Color Vision using Spectroscopy and Nanotechnology: Application to Media Photonics" into an engineering course in the field of media technology. The aim is to develop the existing learning concept towards a more research-oriented teaching. Involving students in research projects as part of the learning process provides a deeper insight into current research topics and the key elements of scientific work. This makes it easier for students to recognize the importance of the acquired theoretical knowledge for the practice, which enables them to derive new insights of their own.
This paper presents an approach for implementing an automated hit detection and score calculation system for a steel dartboard using a standard webcam. First, the rectilinear field separations of the dartboard are described mathematically by means of line slopes and are than stored. These slopes serve as a basis for later score calculation. In addition, thrown darts have to be detected and the pixel at which the dart cuts the dartboard has to be determined. When this information is known, a comparison is made using the line slopes, allowing the field number of the hit to be detected. The decision for single, double or triple hit is made by evaluating the defined colors on the dartboard. All these functions are then packaged in a Matlab GUI.
Hochspannungs-Mischstrom-Übertragung (HMÜ) - Eine Ergänzung zu bestehenden Übertragungstechnologien?
(2019)
Bei der Mischstromübertragung wird einem Wechselstrom direkt ein Gleichstrom überlagert. Wechselstrom und Gleichstrom werden also auf dem gleichen Seil geführt.
Dadurch könnten die bereits bestehenden Drehstrom-Übertragungs-Strecken des Übertragungsnetzes genutzt werden.
Durch eine Aufschaltung des Gleichstromes auf vorhandene Freileitungen kann theoretisch bei kurzen Leitungen (<150km) bis zu 50% mehr Wirkleistung und bei großen Übertragungsstrecken (>300km) in etwa eine Verdopplung der übertragbaren Wirkleistung erwartet werden.
Theoretisch betrachtet ist die Mischstrom-Übertragung eine geometrische Addition aller Strom- und Spannungskomponenten, was zu einer Erhöhung der Leiter-Erde-Spannung führt, ohne dabei Einfluss auf die verkettete Spannung zu nehmen.
Außerdem wird die Übertragung von Blindströmen unnötig, da ein natürlicher Betrieb von Leitungen des HDÜ-Netzes empfehlenswert ist.
Die theoretischen Betrachtungen konnten mathematisch bewiesen und die technische Umsetzung mit einem 1:1000-Modellsystem demonstriert und bestätigt werden.
Kleinstlebewesen vorgestellt, das Vitalparameter erfasst und diese in einem FRAM-Speicher bis zum Auslesen abspeichert. Durch eine drahtlose RFID-/NFC-Ausleseschnittstelle kann die erfasste Körpertemperatur und der Puls der letzten Wochen ausgelesen werden. Alle Einstellungen des Messsystems können durch einen geeigneten RFID-Reader für Laptops oder durch Smartphones über die NFC-Schnittstelle geändert werden. Das vollständige Aufladen des nur 3 g leichten und 15 mm x 25 mm großen Messsystems erfolgt durch eine selbstgedruckte RFID-Reader-Antenne in Verbindung mit einem RFID-Reader und benötigt hierzu weniger als 21 Stunden. Bei vollständig aufgeladenem Energiespeicher ist ein Betrieb von 47 Tagen möglich. Dies wird durch ein speziell für das Messsystem konzipiertes Lade- und Powermanagement erreicht. Neben der Auswahl von energiesparenden Komponenten für die Hardware und deren bestmöglichen Nutzung, wurde die Software so optimiert, dass das Programm schnell und stromsparend abgearbeitet wird. Die Erweiterbarkeit und Anpassung wird durch das modulare Konzept auch in anderen Bereichen gewährleistet.
Top-level staff prefers to live in urban areas with perfect social infrastructure. This is a common problem for excellent companies (“hidden champions”) in rural areas: even if they can provide the services qualified applicants appreciate for daily living, they fail to attract them because important facts are not presented sufficiently in social media or on the corporate website. This is especially true for applicants with families. The contribution of this paper is four-fold: we provide an overview of the current state of online recruiting activities of hidden champions (1). Based on this corpus, we describe the applicant service gap for company information in rural communes (2). A study on user experience (UX) identifies the applicants’ wishes and needs, focusing on a family-oriented information system on living conditions in rural areas (3). Finally, we present the results of an online survey on the value of such information systems with more than 200 participants (4).
The paper describes a systematic approach for a precise short-time cloud coverage prediction based on an optical system. We present a distinct pre-processing stage that uses a model based clear sky simulation to enhance the cloud segmentation in the images. The images are based on a sky imager system with fish-eye lens optic to cover a maximum area. After a calibration step, the image is rectified to enable linear prediction of cloud movement. In a subsequent step, the clear sky model is estimated on actual high dynamic range images and combined with a threshold based approach to segment clouds from sky. In the final stage, a multi hypothesis linear tracking framework estimates cloud movement, velocity and possible coverage of a given photovoltaic power station. We employ a Kalman filter framework that efficiently operates on the rectified images. The evaluation on real world data suggests high coverage prediction accuracy above 75%.
Current training methods for deep neural networks boil down to very high dimensional and non-convex optimization problems which are usually solved by a wide range of stochastic gradient descent methods. While these approaches tend to work in practice, there are still many gaps in the theoretical understanding of key aspects like convergence and generalization guarantees, which are induced by the properties of the optimization surface (loss landscape). In order to gain deeper insights, a number of recent publications proposed methods to visualize and analyze the otimization surfaces. However, the computational cost of these methods are very high, making it hardly possible to use them on larger networks. In this paper, we present the GradVis Toolbox, an open source library for efficient and scalable visualization and analysis of deep neural network loss landscapes in Tesorflow and PyTorch. Introducing more efficient mathematical formulations and a novel parallelization scheme, GradVis allows to plot 2d and 3d projections of optimization surfaces and trajectories, as well as high resolution second order gradient information for large networks.
New employees are supposed to quickly understand their tasks, internal processes and familiarize with colleagues. This process is called “onboarding” and is still mainly realized by organizational methods from human resource management, such as introductory events or special employee sessions. Software tools and especially mobile applications are an innovative means to support provide onboarding processes in a modern, even remote, way. In this paper we analyze how the use of gamification can enhance onboarding processes. Firstly, we describe a mobile onboarding application specifically developed for the young, technically literate generations Y and Z, who are just about to start their career. Secondly, we report on a study with 98 students and young employees. We found that participants enjoyed the gamified application. They especially appreciated the feature “Team Bingo” which facilitates social integration and teambuilding. Based on the OCEAN personality model (“Big Five”), the personality traits agreeableness and openness revealed significant correlations with a preference for the gamified onboarding application.
Formal Description of Use Cases for Industry 4.0 Maintenance Processes Using Blockchain Technology
(2019)
Maintenance processes in Industry 4.0 applications try to achieve a high degree of quality to reduce the downtime of machinery. The monitoring of executed maintenance activities is challenging as in complex production setups, multiple stakeholders are involved. So, full transparency of the different activities and of the state of the machine can only be supported, if these stakeholders trust each other. Therefore, distributed ledger technologies, like Blockchain, can be promising candidates for supporting such applications. The goal of this paper is a formal description of business and technical interactions between non-trustful stakeholders in the context of Industry 4.0 maintenance processes using distributed ledger technologies. It also covers the integration of smart contracts for automated triggering of activities.