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Dieser Beitrag stellt die Möglichkeiten des 3D-Druckes unter der Berücksichtigung von Mensch-Roboter-Kollaborations-Anforderungen dar. Dabei werden die Vorteile mit besonderem Fokus auf die zusätzliche Gestaltungsfreiheit erläutert. Anhand von Beispielen wird der Stand der Technik bereits eingesetzter Sensorik sowie deren Notwendigkeit in Greifsystemen erläutert. Im weiteren Verlauf dieses Beitrags werden allgemeine Verfahren für die additive Verarbeitung von leitfähigen Materialien vorgestellt. Daran angeknüpft sind Beispiele speziell zur 3D-gedruckten Sensorik. Abgerundet wird der Beitrag mit einem Ausblick bezüglich 3D-gedruckter Sensorik in MRK-Greifsystemen.
This paper describes the use of the single-linkage hierarchical clustering method in outlier detection for manufactured metal work pieces. The main goal of the study is to group defects that occur 5 mm into a work piece from the edge, i.e., the border of the metal work piece. The goal is to remove defects outside the area of interest as outliers. According to the assumptions made for the performance criteria, the single-linkage method has achieved better results compared to other agglomeration methods.
Uncontrollable manufacturing variations in electrical hardware circuits can be exploited as Physical Unclonable Functions (PUFs). Herein, we present a Printed Electronics (PE)-based PUF system architecture. Our proposed Differential Circuit PUF (DiffC-PUF) is a hybrid system, combining silicon-based and PE-based electronic circuits. The novel approach of the DiffC-PUF architecture is to provide a specially designed real hardware system architecture, that enables the automatic readout of interchangeable printed DiffC-PUF core circuits. The silicon-based addressing and evaluation circuit supplies and controls the printed PUF core and ensures seamless integration into silicon-based smart systems. Major objectives of our work are interconnected applications for the Internet of Things (IoT).
The increase in households with grid connected Photovoltaic (PV) battery system poses challenge for the grid due to high PV feed-in as a result of mismatch in energy production and load demand. The purpose of this paper is to show how a Model Predictive Control (MPC) strategy could be applied to an existing grid connected household with PV battery system such that the use of battery is maximized and at the same time peaks in PV energy and load demand are reduced. The benefits of this strategy are to allow increase in PV hosting capacity and load hosting capacity of the grid without the need for external signals from the grid operator. The paper includes the optimal control problem formulation to achieve the peak shaving goals along with the experiment set up and preliminary experiment results. The goals of the experiment were to verify the hardware and software interface to implement the MPC and as well to verify the ability of the MPC to deal with the weather forecast deviation. A prediction correction has also been introduced for a short time horizon of one hour within this MPC strategy to estimate the PV output power behavior.
In rural low voltage grid networks, the use of battery in the households with a grid connected Photovoltaic (PV) system is a popular solution to shave the peak PV feed-in to the grid. For a single electricity price scenario, the existing forecast based control approaches together with a decision based control layer uses weather and load forecast data for the on–off schedule of the battery operation. These approaches do bring cost benefit from the battery usage. In this paper, the focus is to develop a Model Predictive Control (MPC) to maximize the use of the battery and shave the peaks in the PV feed-in and the load demand. The solution of the MPC allows to keep the PV feed-in and the grid consumption profile as low and as smooth as possible. The paper presents the mathematical formulation of the optimal control problem along with the cost benefit analysis . The MPC implementation scheme in the laboratory and experiment results have also been presented. The results show that the MPC is able to track the deviation in the weather forecast and operate the battery by solving the optimal control problem to handle this deviation.
A Nonlinear FEM Model to Calculate Third-Order Harmonic and Intermodulation in TC-SAW Devices
(2018)
Nonlinearities in Temperature Compensated SAW (TC-SAW) devices in the 2 GHz range are investigated using a nonlinear finite element model by simultaneously considering both third-order intermodulation distortion (IMD3)and third harmonic (H3). In the employed perturbation approach, different contributions to the total H3, the direct and indirect contribution, are discussed. H3 and IMD3 measurements were fitted simultaneously using scaling factors for SiO 2 film and Cu electrode nonlinear material tensors in TC-SAW devices. We employ a P-Matrix simulation as intermediate step: Firstly, measurement and nonlinear P-Matrix calculations for finite devices are compared and coefficients of the P-Matrix simulation are determined. The nonlinear tensor data of the different materials involved in periodic nonlinear finite element method (FEM) computations are optimized to fit periodic P-Matrix calculations by introducing scaling factors. Thus, the contribution of different materials to the nonlinear behavior of TC-SAW devices is obtained and the role of materials is discussed.
A printed electronics technology has the advantage of additive and extremely low-cost fabrication compared with the conventional silicon technology. Specifically, printed electrolyte-gated field-effect transistors (EGFETs) are attractive for low-cost applications in the Internet-of-Things domain as they can operate at low supply voltages. In this paper, we propose an empirical dc model for EGFETs, which can describe the behavior of the EGFETs smoothly and accurately over all regimes. The proposed model, built by extending the Enz-Krummenacher-Vittoz model, can also be used to model process variations, which was not possible previously due to fixed parameters for near threshold regime. It offers a single model for all the operating regions of the transistors with only one equation for the drain current. Additionally, it models the transistors with a less number of parameters but higher accuracy compared with existing techniques. Measurement results from several fabricated EGFETs confirm that the proposed model can predict the I-V more accurately compared with the state-of-the-art models in all operating regions. Additionally, the measurements on the frequency of a fabricated ring oscillator are only 4.7% different from the simulation results based on the proposed model using values for the switching capacitances extracted from measurement data, which shows more than 2× improvement compared with the state-of-the-art model.
In this article, we present a taxonomy in Robot-Assisted Training; a growing body of research in Human–Robot Interaction which focuses on how robotic agents and devices can be used to enhance user’s performance during a cognitive or physical training task. Robot-Assisted Training systems have been successfully deployed to enhance the effects of a training session in various contexts, i.e., rehabilitation systems, educational environments, vocational settings, etc. The proposed taxonomy suggests a set of categories and parameters that can be used to characterize such systems, considering the current research trends and needs for the design, development and evaluation of Robot-Assisted Training systems. To this end, we review recent works and applications in Robot-Assisted Training systems, as well as related taxonomies in Human–Robot Interaction. The goal is to identify and discuss open challenges, highlighting the different aspects of a Robot-Assisted Training system, considering both robot perception and behavior control.
Hot work tools are subjected to complex thermal and mechanical loads during hot forming processes. Locally, the stresses can exceed the material’s yield strength in highly loaded areas as e.g. in small radii in die cavities. To sustain the high loads, the hot forming tools are typically made of martensitic hot work steels. While temperatures for annealing of the tool steels usually lie in the range between 400 and 600 °C, the steels may experience even higher temperatures during hot forming, resulting in softening of the material due to coarsening of strengthening particles. In this paper, a temperature dependent cyclic plasticity model for the martensitic hot work tool steel 1.2367 (X38CrMoV5-3) is presented that includes softening due to particle coarsening and that can be applied in finite-element calculations to assess the effect of softening on the thermomechanical fatigue life of hot work tools. To this end, a kinetic model for the evolution of the mean size of secondary carbides based on Ostwald ripening is coupled with a cyclic plasticity model with kinematic hardening. Mechanism-based relations are developed to describe the dependency of the mechanical properties on carbide size and temperature. The material properties of the mechanical and kinetic model are determined on the basis of tempering hardness curves as well as monotonic and cyclic tests.
A Validated Quantification of Sudan Red Dyes in Spicery using TLC and a 16-bit Flatbed Scanner
(2018)
We present a video-densitometric quantification method for Sudan red dyes in spices and spice mixtures, separated by TLC. Application was done band-wise in small dots using a 5 μL glass pipette. For separation, the RP-18 plates (20 × 20 cm with fluorescent dye; Merck, Germany, 1.05559) were developed in a vertical developing chamber without vapor saturation from the starting point to a distance of 70 mm by using acetonitrile, methanol, and aqueous ammonia solution (25%; 8 + 1.8 + 0.2, v/v) as mobile phase. The quantification is based on direct measurements using an inexpensive 16-bit flatbed scanner for color measurements (in red, green, and blue). Evaluation of only the green channel makes the measurements very specific. For linearization, an extended Kubelka-Munk expression for data transformation was used. The range of linearity covers more than two magnitudes and lies between 20 and 500 ng. The extraction from a 2 g sample with acetonitrile, evaporation, and reconstitution to 200 μL with methanol and the band-wise application (7 mm) of a 10 μL sample allows a statistically defined LOD of less than 500 ppb of Sudan red dyes. To perform the analysis, a separation chamber, RP-18 plates, 5 μL glass pipettes, and a 16-bit flatbed scanner for 105 € are needed; therefore, the separation method is inexpensive, fast, and reliable.
Membrane distillation (MD) is a thermal separation process which possesses a hydrophobic, microporous
membrane as vapor space. A high potential application for MD is the concentration of hypersaline brines, such as
e.g. reverse osmosis retentate or other saline effluents to be concentrated to a near saturation level with a Zero
Liquid Discharge process chain. In order to further commercialize MD for these target applications, adapted MD
module designs are required along with strategies for the mitigation of membrane wetting phenomena. This
work presents the experimental results of pilot operation with an adapted Air Gap Membrane Distillation
(AGMD) module for hypersaline brine concentration within a range of 0–240 g NaCl /kg solution. Key performance
indicators such as flux, GOR and thermal efficiency are analyzed. A new strategy for wetting mitigation
by active draining of the air gap channel by low pressure air blowing is tested and analyzed. Only small reductions
in flux and GOR of 1.2% and 4.1% respectively, are caused by air sparging into the air gap channel.
Wetting phenomena are significantly reduced by avoiding stagnant distillate in the air gap making the air blower
a seemingly worth- while additional system component.
This paper deals with the detection and segmentation of clouds on high-dynamic-range (HDR) images of the sky as well as the calculation of the position of the sun at any time of the year. In order to predict the movement of clouds and the radiation of the sun for a short period of time, the clouds thickness and position have to be known as precisely as possible. Consequently, the segmentation algorithm has to provide satisfactory results regardless of different weather, illumination and climatic conditions. The principle of the segmentation is based on the classification of each pixel as a cloud or as a sky. This classification is usually based on threshold methods, since these are relatively fast to implement and show a low computational burden. In order to predict if and when the sun will be covered by clouds, the position of the sun on the images has to be determined. For this purpose, the zenith and azimuth angles of the sun are determined and converted into XY coordinates.
Aspekte der Motivation
(2018)
Autonome Systeme im Consumerbereich - Was bedeutet die Autonomie technischer Systeme für den Kunden
(2018)
Dieser Artikel gibt einen Überblick der Möglichkeiten kontextbewusster Systeme und erläutert, wie diese die Autonomie zugleich erweitern und begrenzen können. Anwendungsbeispiele wie autonomes Fahren, Rehabilitation, industrielle Arbeit und Robotik zeigen die technischen Möglichkeiten auf. Neben der Erkennung von räumlichen Details werden auch die Potenziale der Erkennung von Emotionen beschrieben. Dabei wird zugunsten der Allgemeinverständlichkeit auf eine tiefe technische Detaillierung verzichtet, zugleich aber auf die jeweils relevante Forschungsliteratur verweisen.
Benchmarking
(2018)
BGH "Mehrere Werbekanäle"
(2018)
BGH "Preisportal"
(2018)
Big Data Governance
(2018)
Bildung statt Profilbildung
(2018)
Im Rahmen der Konstruktionsausbildung an der Hochschule Offenburg wird die Lehre im Fach Technische Dokumentation fortlaufend optimiert. In der vorliegenden Laborstudie wurde das visuelle Wahrnehmen von 34 Maschinenbaustudierenden (2w + 32m) im Alter von 19 bis 29 Jahren mithilfe der Eye-Tracking-Technik und einer Videokamera bei der Analyse einer Baugruppenzeichnung beobachtet.
Brand identification has the potential of shaping individuals' attitudes, performance and commitment within learning and work contexts. We explore these effects, by incorporating elements of branded identification within gamified environments. We report a study with 44 employees, in which task performance and emotional outcomes are assessed in a real-world assembly scenario - namely, while performing a soldering task. Our results indicate that brand identification has a direct impact on individuals' attitude towards the task at hand: while instigating positive emotions, aversion and reactance also arise.
Business Reengineering
(2018)
Covert- and side-channels as well as techniques to establish them in cloud computing are in focus of research for quite some time. However, not many concrete mitigation methods have been developed and even less have been adapted and concretely implemented by cloud providers. Thus, we recently conceptually proposed C 3 -Sched a CPU scheduling based approach to mitigate L2 cache covert-channels. Instead of flushing the cache on every context switch, we schedule trusted virtual machines to create noise which prevents potential covert-channels. Additionally, our approach aims on preserving performance by utilizing existing instead of artificial workload while reducing covert-channel related cache flushes to cases where not enough noise has been achieved. In this work we evaluate cache covert-channel mitigation and performance impact of our integration of C 3 -Sched in the XEN credit scheduler. Moreover, we compare it to naive solutions and more competitive approaches.
Cell lifetime diagnostics and system be-havior of stationary LFP/graphite lithium-ion batteries
(2018)
Real-Time Ethernet has become the major communication technology for modern automation and industrial control systems. On the one hand, this trend increases the need for an automation-friendly security solution, as such networks can no longer be considered sufficiently isolated. On the other hand, it shows that, despite diverging requirements, the domain of Operational Technology (OT) can derive advantage from high-volume technology of the Information Technology (IT) domain. Based on these two sides of the same coin, we study the challenges and prospects of approaches to communication security in real-time Ethernet automation systems. In order to capitalize the expertise aggregated in decades of research and development, we put a special focus on the reuse of well-established security technology from the IT domain. We argue that enhancing such technology to become automation-friendly is likely to result in more robust and secure designs than greenfield designs. Because of its widespread deployment and the (to this date) nonexistence of a consistent security architecture, we use PROFINET as a showcase of our considerations. Security requirements for this technology are defined and different well-known solutions are examined according their suitability for PROFINET. Based on these findings, we elaborate the necessary adaptions for the deployment on PROFINET.
Solar irradiance prediction is vital for the power management and the cost reduction when integrating solar energy. The study is towards a ground image based solar irradiance prediction which is highly dependent on the cloud coverage. The sky images are collected by using ground based sky imager (fisheye lens). In this work, different algorithms for cloud detection being a preparation step for their segmentation are compared.
The comprehensive assessment method includes 80 innovation performance parameters and 10 key indicators of innovation capability, such as innovation process performance, innovating system performance, market and customer orientation, technology orientation, creativity, leadership, communication and knowledge management, risk and cost management, innovative climate, and innovation competences. The cross-industry study identifies parameters critical for innovation success and reveals different innovation performance patterns in companies.
In this paper the yield surface of a recently presented microstructure-based volume element of the gray cast iron material GJL-250 is assessed after different plastic loading histories. The evolution of the yield surface is investigated for different volumetric, deviatoric and uniaxial loadings. The micromechanical material properties of the metallic matrix and the graphite inclusions are validated by means experimental stress-strain hysteresis loops. The metallic matrix is modeled as elastic-plastic with a non-linear kinematic hardening law. The graphite inclusions are described by means of a volumetric strain state dependent Young’s modulus. The results show that the shape of the yield surface does not change significantly in comparison to the initial yield surface after pure deviatoric loadings. After volumetric loadings, the dependence of the material on the Lode angle is significantly reduced. Uniaxial tensile preloadings result in a deformed yield surface, whereby the magnitude of the deformation depends on the applied load. Uniaxial preloadings to compression do not change the shape of the initial yield surface.
Nowadays, robotic systems are an integral part of many orthopedic interventions. Stationary robots improve the accuracy but also require adapted surgical workflows. Handheld robotic devices (HHRDs), however, are easily integrated into existing workflows and represent a more economical solution. Their limited range of motion is compensated by the dexterity of the surgeon. This work presents control algorithms for HHRDs with multiple degrees of freedom (DOF). These algorithms protect pre- or intraoperatively defined regions from being penetrated by the end effector (e.g., a burr) by controlling the joints as well as the device’s power. Accuracy tests on a stationary prototype with three DOF show that the presented control algorithms produce results similar to those of stationary robots and much better results than conventional techniques. This work presents novel and innovative algorithms, which work robustly, accurately, and open up new opportunities for orthopedic interventions.
Conversion-Killer in Onlineshops - Identifikation von Kundenorientierung anhand von Mimikindikatoren
(2018)
Mimik als Ausdrucksform von Emotionen ist, seitdem es die Menschheit gibt, ein zentrales Verständigungsmittel in der Kommunikation. Da das Gegenüber in der Interaktion heute in vielen Situationen des täglichen Lebens eine Maschine ist, wäre es vorstellbar, dass die Mimik als Emotionsträger und Kommunikationsmittel seine Bedeutung verliert. Dies ist ein Irrtum: In der vorliegenden Untersuchung wird im Rahmen einer umfassenden Studie festgestellt, dass Mimik von der menschlichen Kommunikation schwer trennbar ist und auch in der Interaktion mit Maschinen unvermindert auftritt. Diese Erkenntnis kann Unternehmen helfen, den Mensch-Maschine-Dialog genau zu analysieren, um erfolgsmindernde Kundenirritationen zu eliminieren und die Abläufe optimal auf die Bedürfnisse der Nutzer anpassen zu können.
Corporate Governance
(2018)
Pulmonary vein isolation (PVI) is a common therapy in atrial fibrillation (AF). The cryoballoon was invented to isolate the pulmonary vein in one step and in a shorter time than a point-by-point radiofrequency (RF) ablation. The aim of the study was to model two cryoballoon catheters, one RF catheter and to integrate them into a heart rhythm model for the static and dynamic simulation of PVI by cryoablation and RF ablation in AF. The modeling and simulation were carried out using the electromagnetic and thermal simulation software CST (CST, Darmstadt). Two cryoballons and one RF ablation catheter were modeled based on the technical manuals of the manufacturers Medtronic and Osypka. The PVI especially the isolation of the left inferior pulmonary vein using a cryoballoon catheter was performed with a -50 °C heatsource and an exponential signal. The temperature at the balloon surface was -50 °C after 20 s ablation time, -24 °C from the balloon 0,5 mm in the myocardium, at a distance of 1 mm -3 °C, at 2 mm 18 °C and at a distance of 3mm 29 °C. PVI with RF energy was simulated with an applied power of 5 W at 420 kHz at the distal 8 mm ablation electrode. The temperature at the tip electrode was 110 °C after 15 s ablation time, 75 °C from the balloon at 0,5 mm in the myocardium, at a distance of 1 mm 58 °C, at 2 mm 45 °C and at a distance of 3 mm 38 °C. Virtual heart rhythm and catheter models as well as the simulation of the temperature allow the simulation of PVI in AF by cryo ablation and RF ablation. The 3D simulation of the temperature profile may be used to optimize RF and cryo ablation.
Wer sich mit der Fragestellung von Autonomie – verstanden im ursprünglichen Sinn von Selbständigkeit und Unabhängigkeit – im Zusammenhang mit Kreation und Gestaltung beschäftigt, merkt schnell, dass bei aller Modernität der heutigen Digitaltechniken ein uraltes Thema auftaucht: die grundsätzliche Abhängigkeit des schöpferischen Aktes von Technik und Material, von Handwerk und Produktionsbedingungen.
Die digitale Transformation als Vernetzung von Menschen, Organisationen, Maschinen, bis hin zu simplen Gegenständen des täglichen Lebens hat mehr oder weniger starke Auswirkungen auf alle Lebensbereiche. Künstliche Intelligenz und autonome technische Systeme haben direkte Auswirkungen auf die Autonomie des Einzelnen, was neue Fragen für Wissenschaft und Praxis aufwirft. In unterschiedlichen Beiträgen werden Autonomiegewinne und -verluste skizziert, die sich unter anderem im Bereich des Rechts, der Informations- und Kommunikationstechnologien, in Kunst und Gestaltung, bei Kundenbeziehungen, Kryptowährungen, Medieninhalten sowie im digitalen Arbeitsalltag feststellen lassen. Kritische Entwicklungen wie digitale Sorglosigkeit und Tools und Verfahren wie Projektmanagementsoftware oder predictive analytics gilt es dabei zu bewerten. Damit liefert dieser Band einen Überblick zum aktuellen Stand der Diskussion, zeigt Zusammenhänge auf und sensibilisiert für die Gestaltung des digitalen Wandels.
Data Science gilt als eine der wichtigsten Entwicklungen der letzten
Jahre und viele Unternehmen sehen in Data Science die Möglichkeit,
ihre Daten zusätzlich wertschöpfend zu nutzen. Dabei kann es sich um
die Optimierung von Maintenance-Prozessen handeln, um eine bessere
Steuerung der eigenen Preis- und Lagerhaltungsstrategie oder auch
um völlig neue Services und Produkte, die durch Data Science möglich
werden. Die im Unternehmen vorliegenden Daten, an die so hohe Erwartungen
geknüpft wurden, sollen dazu genutzt werden, um Services
und Prozesse effizienter und passgenauer gestalten zu können. Vielfach
gilt Data Science dabei als Allheilmittel: Daten, die über Jahre hinweg
gesammelt wurden und mit zunehmender Geschwindigkeit und Heterogenität
anfallen, sollen endlich nutzbar gemacht werden. Zwar sind die
eingesetzten Techniken und Algorithmen teilweise schon zehn Jahre und
mehr alt, doch erst jetzt entfalten sie im Zusammenspiel mit Big Data
ihr Potenzial im Unternehmensumfeld. Die Erwartungen sind hoch, doch
der Weg zu den neuen Erkenntnissen ist mit hohem Aufwand verbunden
und wird von einigen Unternehmen noch immer unterschätzt.
Für Unternehmen mit einem traditionellen BI-Ansatz stellt Data Science
ein ergänzendes Set von Methoden und Werkzeugen dar, mit deren Hilfe
die Informationsversorgung der Entscheider auf den verschiedenen
hierarchischen Ebenen noch besser gestaltet werden kann. So zum Beispiel,
wenn man mit Data Science feststellt, dass die Wahrscheinlichkeit
für einen Versicherungsabschluss steigt, wenn bei der Auswahl der
anzusprechenden Kunden zusätzliche Daten herangezogen werden, die
zwar bereits vorliegen, aber noch nicht berücksichtigt worden sind. Im
Extremfall werden auch Entscheidungen vollständig automatisiert, die
bisher von Mitarbeiterinnen und Mitarbeitern getroffen wurden. Ein Algorithmus
legt dann fest, wann Ware nachbestellt oder welcher Preis für
den Endkunden festgesetzt wird.
Im vorliegenden E-Book soll ein Überblick über das Gebiet Data Science
gegeben werden. Dabei wird ein besonderes Augenmerk auf das Zusammenspiel
sowie das Mit- und Nebeneinander von Data Science und vorhandenen
BI-Systemen gelegt.
Delphi-Technik
(2018)
Die Einbindung von Mini- und Mikro-BHKW in ein virtuelles Kleinkraftwerk (VKK) bietet vielfältige wirtschaftliche, Smart-Grids- und Klimaschutzpotentiale zur Unterstützung der "Wärmewende". Eine Einbindung solcher Anlagen ist bisher jedoch mit zumeist hohen Kosten verbunden, weshalb i.d.R. nur Anlagen in höheren Leistungsklassen (> 500 kWel) umgesetzt werden. Im Rahmen des Projekts mikroVKK wurde deshalb das Ziel verfolgt zu demonstriert und nachzuweisen, dass auch BHKW-Anlagen unter 100 kWel in ein virtuelles Kleinkraftwerk (VKK) wirtschaftlich einzubinden sind.
GridSystronic Energy (GSE) hat hierfür ein spezielles VKK-System (gs.system) entwickelt, welches im Rahmen des Projekts unter realen Bedingungen erprobt, weiterentwickelt und möglichst zur Marktreife gebracht wurde. Durch die Konfiguration des Systems - d.h. einfache Steuerboxen (gs.box) werden als Gateway für die Kommunikation vor Ort zur Anlagen- und Zähleranbindung verbaut, wohingegen die Berechnungen, Simulationen und Optimierung der Steuersignale auf dem zentralen gs.server erfolgt - lässt sich eine kostengünstige und skalierbare Lösung darstellen.
Zusammen mit zehn Stadtwerken als Praxispartner wurden unterschiedliche BHKW- Standorte identifiziert und auf deren technische Eignung und die Umsetzbarkeit neuer Geschäftsmodelle auf Basis einer intelligenten Steuerung analysiert. Für ausgewählte Objekte, wie z.B. Schulen, Wärmenetze, Mehrfamiliengebäude, wurde durch GSE eine Anbindung der für die Regelung notwendigen Geräte und Zähler realisiert. Regelwerke, wie z.B. "Lastprofil folgen", als Basis für neue Geschäftsmodelle wurden mit den Praxispartnern abgestimmt und entwickelt. Anhand der Erkenntnisse zu den Effekten der intelligenten Steuerung (z.B. Nutzung von möglichen Flexibilitäten, Stabilität des Systems, Verschiebung der Betriebszeiten, Änderung der Lieferquoten etc.) wurden neue Geschäftsmodelle detailliert analysiert und mit den Praxispartnern prototypisch umgesetzt. Die Evaluation zu den Smart-Grids-Potenzialen (Flexibilität, netzdienliche Einspeisung etc.) sowie die Potenziale zur Unterstützung des Klimaschutzes (CO2-Minderung) erfolgte anhand von gemessenen und simulierten Werten.
Während der Projektlaufzeit konnte die technische Anbindbarkeit von BHKW-Anlagen mit einer elektrischen Leistung bis 100 kWel demonstriert werden. Die Vorarbeiten für die Erarbeitung einer standardisierten und kostengünstigen Anbindungslösung war jedoch sehr viel zeitintensiver als ursprünglich geplant, weshalb die Anlagen verspätet oder z.T. gar nicht angebunden werden konnten. Wegen der geringen Datenbasis konnten die grundsätzlichen wirtschaftlichen Potenziale einer VKK Steuerung deshalb nur auf theoretischer Basis nachgewiesen werden. Die Anbindungs- und Integrationskosten hängen stark von den örtlichen Gegebenheiten ab, weshalb es hierfür keine pauschale Aussage getroffen werden kann. Durch die gewonnenen Erfahrungen und Lernprozesse konnte jedoch im Laufe des Projektes bereits eine erhebliche Kostenreduktion erzielt werden. Auch bei Neuanlagen, bei denen die Anbindung bereits vorab eingeplant werden kann, können die Kosten der Anbindung stark reduziert werden. Die Smart-Grid-Potenziale und die Klimaschutzpotenziale eines VKK-Einsatzes wurden von der Hochschule Offenburg ebenfalls auf einer theoretischen Basis ermittelt. In einem nächsten Schritt wäre es deshalb notwendig zu analysieren, ob sich die ermittelten Effekte auch unter realen Bedingungen einstellen.
Der Spion im Klassenzimmer
(2018)
Printed Electronics (PE) is a promising technology that provides mechanical flexibility and low-cost fabrication. These features make PE the key enabler for emerging applications, such as smart sensors, wearables, and Internet of Things (IoTs). Since these applications need secure communication and/or authentication, it is vital to utilize security primitives for cryptographic key and identification. Physical Unclonable Functions (PUF) have been adopted widely to provide the secure keys. In this work, we present a weak PUF based on Electrolyte-gated FETs using inorganic inkjet printed electronics. A comprehensive analysis framework including Monte Carlo simulations based on real device measurements is developed to evaluate the proposed PE-PUF. Moreover, a multi-bit PE-PUF design is proposed to optimize area usage. The analysis results show that the PE-PUF has ideal uniqueness, good reliability, and can operates at low voltage which is critical for low-power PE applications. In addition, the proposed multi-bit PE-PUF reduces the area usage around 30%.
Existing ultrasonic stress evaluation methods utilize the acoustoelastic effect for bulk waves propagating in volume, which is unsuitable for a surface treated material, possessing a significant variation in material properties with depth. With knowledge of nonlinear elastic parameters – third-order elastic constants (TOEC) close to the surface of the sample, the acoustoelastic effect might be used with surface acoustic waves. This work is focused on the development of an independent method of TOEC measurement using the effect of nonlinear surface acoustic waves scattering – i.e. the effect of elastic waves interaction in a nonlinear medium.
In this paper, the possible three wave interactions of surface guided waves and bulk waves are described and formulae for the efficiency of harmonic generation and mode mixing are derived. A comparison of the efficiency of surface waves scattering in an isotropic medium for different interaction types is carried out with the help of nonlinear perturbation theory. First results for surface and bulk wave mixing with known second- and third-order elastic constants are shown.
Einführender Überblick
(2018)
Einleitung
(2018)
Cardiac resynchronization therapy (CRT) with hemodynamic optimized biventricular pacing is an established therapy for heart failure patients with sinus rhythm, reduced left ventricular ejection fraction and wide QRS complex. The aim of the study was to evaluate electrical right and left cardiac atrioventricular delay and left atrial delay in CRT responder and non-responder with sinus rhythm.
Methods: Heart failure patients with New York Heart Association class 3.0 ± 0.3, sinus rhythm and 27.7 ± 6.1% left ventricular ejection fraction were measured by surface ECG and transesophageal bipolar left atrial and left ventricular ECG before implantation of CRT devices. Electrical right cardiac atrioventricular delay was measured between onset of P wave and onset of QRS complex in the surface ECG, left cardiac atrioventricular delay between onset of left atrial signal and onset of left ventricular signal in the transesophageal ECG and left atrial delay between onset and offset of left atrial signal in the transesophageal ECG.
Results: Electrical atrioventricular and left atrial delay were 196.9 ± 38.7 ms right and 194.5 ± 44.9 ms left cardiac atrioventricular delay, and 47.7 ± 13.9 ms left atrial delay. There were positive correlation between right and left cardiac atrioventricular delay (r = 0.803 P < 0.001) and negative correlation between left atrial delay and left ventricular ejection fraction (r = −0.694 P = 0.026) with 67% CRT responder.
Conclusions: Transesophageal electrical left cardiac atrioventricular delay and left atrial delay may be useful preoperative atrial desynchronization parameters to improve CRT optimization.
The high frequency (HF) catheter ablation is the gold standard for the therapy of many cardiac tachyarrhythmias, such as atrioventricular node re-entry tachycardia (AVNRT), atrioventricular re-entry tachycardia (AVRT) or atrial flutter (AFL). The aim of the study was to simulate the HF ablation of AVNRT, AVRT, AFL and its heat propagation in reference to the supplied power with different electrode material and electrode size. The modeling and simulation were performed with the thermal and electromagnetic simulation software CST® (Computer Simulation Technology, Darmstadt). The modeling and simulation were carried out using ablation catheters with 4 mm tip electrode and 8 mm tip electrode with different electrode materials. Both electrode types were made of platinum and gold respectively. For the measurement of the heat propagation in the heart tissue, the catheters were integrated in the Offenburg heart rhythm model. The HF ablation procedures were performed with the 4 mm platinum tip electrode, with an application duration of 45 seconds and a power output of 40 watts. The HF ablation of the atrioventricular node slow pathway produced a maximum temperature of 66.33 °C. The Kent bundle HF ablation in the left atrium achieved a maximum temperature of 67.14 °C. The HF ablation of the right atrial isthmus resulted 65.96 °C. The 8 mm distal platinum tip electrode and a power output of 60 watts reached 72.85 °C. The 8 mm distal gold tip electrode and a power output of 60 watt reached 64.66 °C, due to the improved thermal conductivity of gold. Virtual heart and ablation electrode models allow the static and dynamic simulation of HF ablation with different electrode material and electrode size. The 3D simulation of the temperature profile may be used to optimize the AVNRT, AVRT and AFL HF ablation.
Deafblindness is a condition that limits communication capabilities primarily to the haptic channel. In the EU-funded project SUITCEYES we design a system which allows haptic and thermal communication via soft interfaces and textiles. Based on user needs and informed by disability studies, we combine elements from smart textiles, sensors, semantic technologies, image processing, face and object recognition, machine learning, affective computing, and gamification. In this work, we present the underlying concepts and the overall design vision of the resulting assistive smart wearable.
CONTEXT
The paper addresses the needs of medium and small businesses regarding qualification of R&D specialists in the interdisciplinary cross-industry innovation, which promises a considerable reduction of investments and R&D expenditures. The cross-industry innovation is commonly understood as identification of analogies and transfer of technologies, processes, technical solutions, working principles or business models between industrial sectors. However, engineering graduates and specialists frequently lack the advanced skills and knowledge required to run interdisciplinary innovation across the industry boundaries.
PURPOSE
The study compares the efficiency of the cross-industry innovation methods in one semester project-oriented course. It identifies the individual challenges and preferred working techniques of the students with different prior knowledge, sets of experiences, and cultural contexts, which require attention by engineering educators.
APPROACH
Two parallel one-semester courses were offered to the mechanical and process engineering students enrolled in bachelor’s and master’s degree programs at the faculty of mechanical and process engineering. The students from different years of study were working in 12 teams of 3…6 persons each on different innovation projects, spending two hours a week in the classroom and additionally on average two hours weekly on their project research. Students' feedback and self-assessments concerning gained skills, efficiency of learned tools and intermediate findings were documented, analysed, and discussed regularly along the course.
RESULTS
Analysis of numerous student projects allows to compare and to select the tools most appropriate for finding cross-industry solutions, such as thinking in analogies, web monitoring, function-oriented search, databases of technological effects and processes, special creativity techniques and others. The utilization of learned skills in practical innovation work strengthens the motivation of students and enhances their entrepreneurial competences. Suggested learning course and given recommendations help facilitate sustainable education of ambitious specialists.
CONCLUSIONS
The structured cross-industry innovation can be successfully run as a systematic process and learned in one semester course. The choice of the preferred working teqniques made by the students is affected by their prior knowledge in science, practical experience, and cultural contexts. Major outcomes of the students’ innovation projects such as feasibility, novelty and customer value of the concepts are primarily influenced by students’ engineering design skills, prior knowledge of the technologies, and industrial or business experience.
Entscheidungsfindung: Die Rolle der Kundenemotionen – Was Mimik über Emotion und Entscheidung verrät
(2018)
Entscheidungstechniken
(2018)
Die Hersteller von Cochlea-Implantat (CI)-Systemen sehen für klinische Audiologen die Möglichkeit vor, die Mikrofonleistung der meisten aktuellen CI-Sprachprozessoren mittels anschließbarer Monitorkopfhörer zu prüfen. Nähere Angaben dazu, nach welchem Prozedere diese Prüfung stattfinden soll, z. B. welche Stimuli mit welchen Pegeln verwendet werden sollen, sind nach Wissen der Autoren seitens der CI-Hersteller nicht verfügbar. Auf der Basis dieser subjektiven Prüfung entscheidet dann der Audiologe, ob der betreffende Sprachprozessor an den Hersteller eingeschickt wird oder nicht. Wir haben eine Messbox entwickelt, mit der die Mikrofonleistung aller abhörbaren CI-Sprachprozessoren der Hersteller Advanced Bionics, Cochlear und MED-EL objektiv geprüft werden kann. Die Box wurde im 3-D-Druckverfahren hergestellt. Der zu prüfende Sprachprozessor wird in die Messbox eingehängt und über einen verbauten Lautsprecher mit definierten Prüfsignalen (Sinustönen unterschiedlicher Frequenz) beschallt. Das Signal des Mikronfons bzw. der Mikrofone wird über das in der Audio-/Abhörbuchse des Prozessors eingesteckte Kabel der Monitorkopfhörer herausgeführt und mit einer Shifting and Scaling-Schaltung in einen Spannungsbereich transformiert, der für die A/D-Wandlung mit einem Mikrokontroller (ATmega1280 verbaut auf einem Arduino Mega) geeignet ist. Derselbe Mikrokontroller übernimmt über einen eigens gebauten D/AWandler die Ausgabe der Prüfsignale über den Lautsprecher. Signalaufnahme und –wiedergabe erfolgt jeweils mit einer Samplingrate von 38,5 kHz. Der frequenzspezifische Effektivwert des abgegriffenen Mikrofonsignals wird mit einem Referenzwert verglichen. Die (frequenzspezifischen) Referenzwerte wurden mit einem neuwertigen Sprachprozessor gleichen Typs ermittelt und im Speicher des Mikrokontrollers abgelegt. Das Ergebnis wird nach Abschluss der Messung grafisch auf einem Touchscreen ausgegeben. Derzeit läuft eine erste Datenerhebung mit in der Klinik subjektiv auffällig gewordenen CI-Sprachprozessoren, die anschließend in der Messbox untersucht werden. Längerfristiges Ziel ist es, die hit und false alarm Raten der subjektiven Prüfung zu ermitteln.
Economic growth and ecological problems have pushed industries to switch to eco-friendly technologies. However, environmental impact is still often neglected since production efficiency remains the main concern. Patent analysis in the field of process engineering shows that, on the one hand, some eco-issues appear as secondary problems of the new technologies, and on the other hand, eco-friendly solutions often show lower efficiency or performance capability. The study categorizes typical environmental problems and eco-contradictions in the field of process engineering involving solids handling and identifies underlying inventive principles that have a higher value for environmental innovation. Finally, 42 eco-innovation methods adapting TRIZ are chronologically presented and discussed.
Erfolgsfaktorenforschung
(2018)
Die Frage nach der Erforderlichkeit der Benennung eines Datenschutzbeauftragten wird derzeit oft gestellt. Der Beitrag gibt anhand einer Checkliste Leitlinien zu ihrer Beantwortung. Diese richtet sich seit dem 25.5.2018 bei nicht-öffentlichen Stellen (namentlich Unternehmen, aber auch Vereinen) nach Art. 37 DSGVO und § 38 BDSG n.F.
Die Frage nach der Erforderlichkeit der Benennung eines Datenschutzbeauftragten wird derzeit oft gestellt. Der Beitrag gibt anhand einer Checkliste Leitlinien zu ihrer Beantwortung. Diese richtet sich seit dem 25.5.2018 bei nicht-öffentlichen Stellen (namentlich Unternehmen, aber auch Vereinen) nach Art. 37 DSGVO und § 38 BDSG n.F.
Lithium-ion pouch cells with lithium titanate (Li4Ti5O12, LTO) anode and lithium nickel cobalt aluminum oxide (LiNi0.8Co0.15Al0.05O2, NCA) cathode were investigated experimentally with respect to their electrical (0.1C…4C), thermal (5 °C…50 °C) and long-time cycling behavior. The 16 Ah cell exhibits an asymmetric charge/discharge behavior which leads to a strong capacity-rate effect, as well as a significantly temperature-dependent capacity (0.37 Ah ∙ K−1) which expresses as additional high-temperature feature in the differential voltage plot. The cell was cycled for 10,000 cycles inbetween the nominal voltage limits (1.7–2.7 V) with a symmetric 4C constant-current charge/discharge protocol, corresponding to approx. 3400 equivalent full cycles. A small (0.192 mΩ/1000 cycles) but continuous increase of internal resistance was observed. Using electrochemical impedance spectroscopy (EIS), this could be identified to be caused by the NCA cathode, while the LTO anode showed only minor changes during cycling. The temperature-corrected capacity during 4C cycling exhibited a decrease of 1.28%/1000 cycles. The 1C discharge capacity faded by only 4.0% for CC discharge and 2.3% for CCCV discharge after 10,000 cycles. The cell thus exhibits very good internal-resistance stability and excellent capacity retention even under harsh (4C continuous) cycling, demonstrating the excellent stability of LTO as anode material.
Our media-artistic performances and installations, INTERCORPOREAL SPLITS (2010–2013), BUZZ (2014–2015), W ASTELAND (2015–2016), as well as our new collaboration with Bruno Latour , DE\GLOBALIZE (2018–2020), are not just about polyphony. Here, however, we rediscover them under this heading, thus giving them a new twist, while mapping out issues, mechanisms and functional modes of the polyphonic.
The production of potable water in dry areas nowadays is mainly done by the desalination of seawater. State of the art desalination plants usually are built with high production capacities and consume a lot of electrical energy or energy from primary resources such as oil. This causes difficulties in rural areas, where no infrastructure is available neither for the plants’ energy supply nor the distribution of the produced potable water. To address this need, small, self-sustaining and locally operated desalination plants came into the focus of research. In this work, a novel flash evaporator design is proposed which can be driven either by solar power or by low temperature waste heat. It offers low operation costs as well as easy maintenance. The results of an experimental setup operated with water at a feed flow rate of up to 1,600 l/h are presented. It is shown that the proof of concept regarding efficient evaporation as well as efficient gas-liquid separation is provided successfully. The experimental evaporation yield counts for 98 % of the vapor content that is expected from the vapor pressure curve of water. Neither measurements of the electrical conductivity of the gained condensate, nor the analysis of the vapor flow by optical methods show significant droplet entrainment, so there are no concerns regarding the purity of the produced condensate for the use as drinking water.