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The number of use cases for autonomous vehicles is increasing day by day especially in commercial applications. One important application of autonomous vehicles can be found within the parcel delivery section. Here, autonomous cars can massively help to reduce delivery efforts and time by supporting the courier actively. One important component of course is the autonomous vehicle itself. Nevertheless, beside the autonomous vehicle, a flexible and secure communication architecture also is a crucial key component impacting the overall performance of such system since it is required to allow continuous interactions between the vehicle and the other components of the system. The communication system must provide a reliable and secure architecture that is still flexible enough to remain practical and to address several use cases. In this paper, a robust communication architecture for such autonomous fleet-based systems is proposed. The architecture provides a reliable communication between different system entities while keeping those communications secure. The architecture uses different technologies such as Bluetooth Low Energy (BLE), cellular networks and Low Power Wide Area Network (LPWAN) to achieve its goals.
Erfinderisches Problemlösen mit TRIZ : Zielbeschreibung, Problemdefinition und Lösungspriorisierung
(2017)
Die Theorie des erfinderischen Problemlösens, TRIZ, ist eine Systematik von Annahmen, Regeln, Methoden und Werkzeugen zur innovativen Systemverbesserung z.B. von Produkten, Prozessen, Dienstleistungen oder Organisationen. Diese Richtlinie erläutert TRIZ-Werkzeuge und -Methoden, die insbesondere in den Phasen "Zielbeschreibung", "Problemdefinition" und "Lösungspriorisierung" des Problemlösungsprozesses eingesetzt werden. Die Detailtiefe der Beschreibung erlaubt eine Einschätzung der Werkzeuge und Methoden hinsichtlich Einsatzzwecken, Ergebnissen und Funktionsweise. Die jeweilige Beschreibung der Methoden und Werkzeuge enthält konkrete Aussagen über Zielsetzung und Ergebnis ihres Einsatzes.
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.
A systematic toxicological analysis procedure using high-performance thin layer chromatography in combination with fibre optical scanning densitometry for identification of drugs in biological samples is presented. Two examples illustrate the practicability of the technique. First, the identification of a multiple intake of analgesics: codeine, propyphenazone, tramadol, flupirtine and lidocaine, and second, the detection of the sedative diphenhydramine. In both cases, authentic urine specimens were used. The identifications were carried out by an automatic measurement and computer-based comparison of in situ UV spectra with data from a compiled library of reference spectra using the cross-correlation function. The technique allowed a parallel recording of chromatograms and in situ UV spectra in the range of 197–612 nm. Unlike the conventional densitometry, a dependency of UV spectra by concentration of substance in a range of 250–1000 ng/spot was not observed.
Passive solar elements for both direct and indirect gains, are systems used to maintain a comfortable living environment while saving energy, especially in the building energy retrofit and adaptation process. Sunspaces, thermal mass and glazing area and orientation have been often used in the past to guarantee adequate indoor conditions when mechanical devices were not available. After a period of neglect, nowadays they are again considered as appropriate systems to help face environmental issues in the building sector, and both international and national legislation takes into consideration the possibility of including them in the building planning tools, also providing economic incentives. Their proper design needs dynamic simulation, often difficult to perform and time consuming. Moreover, results generally suffer from several uncertainties, so quasi steady-state procedures are often used in everyday practice with good results, but some corrections are still needed. In this paper, a comparative analysis of different solutions for the construction of verandas in an existing building is presented, following the procedure provided by the slightly modified and improved Standard EN ISO 13790:2008. Advantages and disadvantages of different configurations considering thermal insulation, windows typology and mechanical ventilation systems are discussed and a general intervention strategy is proposed. The aim is to highlight the possibility of using sunspaces in order to increase the efficiency of the existing building stock, considering ease of construction and economic viability.
Energy Performance of Verandas in the Building Retrofit Process (PDF Download Available). Available from: https://www.researchgate.net/publication/303093420_Energy_Performance_of_Verandas_in_the_Building_Retrofit_Process [accessed Jul 5, 2017].
The excessive control signaling in Long Term Evolution networks required for dynamic scheduling impedes the deployment of ultra-reliable low latency applications. Semi-persistent scheduling was originally designed for constant bit-rate voice applications, however, very low control overhead makes it a potential latency reduction technique in Long Term Evolution. In this paper, we investigate resource scheduling in narrowband fourth generation Long Term Evolution networks through Network Simulator (NS3) simulations. The current release of NS3 does not include a semi-persistent scheduler for Long Term Evolution module. Therefore, we developed the semi-persistent scheduling feature in NS3 to evaluate and compare the performance in terms of uplink latency. We evaluate dynamic scheduling and semi-persistent scheduling in order to analyze the impact of resource scheduling methods on up-link latency.
Vehicle-to-Everything (V2X) communication promises improvements in road safety and efficiency by enabling low-latency and reliable communication services for vehicles. Besides using Mobile Broadband (MBB), there is a need to develop Ultra Reliable Low Latency Communications (URLLC) applications with cellular networks especially when safety-related driving applications are concerned. Future cellular networks are expected to support novel latencysensitive use cases. Many applications of V2X communication, like collaborative autonomous driving requires very low latency and high reliability in order to support real-time communication between vehicles and other network elements. In this paper, we classify V2X use-cases and their requirements in order to identify cellular network technologies able to support them. The bottleneck problem of the medium access in 4G Long Term Evolution(LTE) networks is random access procedure. It is evaluated through simulations to further detail the future limitations and requirements. Limitations and improvement possibilities for next generation of cellular networks are finally detailed. Moreover, the results presented in this paper provide the limits of different parameter sets with regard to the requirements of V2X-based applications. In doing this, a starting point to migrate to Narrowband IoT (NB-IoT) or 5G - solutions is given.
The next generation cellular networks are expected to improve reliability, energy efficiency, data rate, capacity and latency. Originally, Machine Type Communication (MTC) was designed for low-bandwidth high-latency applications such as, environmental sensing, smart dustbin, etc., but there is additional demand around applications with low latency requirements, like industrial automation, driver-less cars, and so on. Improvements are required in 4G Long Term Evolution (LTE) networks towards the development of next generation cellular networks for providing very low latency and high reliability. To this end, we present an in-depth analysis of parameters that contribute to the latency in 4G networks along with a description of latency reduction techniques. We implement and validate these latency reduction techniques in the open-source network simulator (NS3) for narrowband user equipment category Cat-Ml (LTE-M) to analyze the improvements. The results presented are a step towards enabling narrowband Ultra Reliable Low Latency Communication (URLLC) networks.
Integration of BACNET OPC UA-Devices Using a JAVA OPC UA SDK Server with BACNET Open Source Library
(2014)
Elektronische Türschilder zur Darstellung von Informationen sind insbesondere in öffentlichen Gebäuden zwischenzeitlich weit verbreitet. Die Varianz dieser elektronischen Türschilder reicht vom Tablet-basierten Türschild bis hin zum PC-basierten Türschild mit externem Bildschirm. Zumeist werden die Systeme mit 230 V betrieben. Bei einer großen Summe von Türschildern in öffentlichen Gebäuden kann dies zu einem signifikanten Umsatz an Energie führen. Im Rahmen dieses Papers wird die Entwicklung eines energieautarken arbeiten Türschildes vorgestellt, bei dem ein E-Paper-Display zum Einsatz kommt. Das Türschild lässt sich per Smartphone-App und NFC-Schnittstelle konfigurieren. Es wird insbesondere auf das Low-Power-Hardware-Design der Elektronik und energetische Aspekte eingegangen.
Users of a cochlear implant (CI) in one ear, who are provided with a hearing aid (HA) in the contralateral ear, so-called bimodal listeners, are typically affected by a constant and relatively large interaural time delay offset due to differences in signal processing and differences in stimulation. For HA stimulation, the cochlear travelling wave delay is added to the processing delay, while for CI stimulation, the auditory nerve fibers are stimulated directly. In case of MED-EL CI systems in combination with different HA types, the CI stimulation precedes the acoustic HA stimulation by 3 to 10 ms. A self-designed, battery-powered, portable, and programmable delay line was applied to the CI to reduce the device delay mismatch in nine bimodal listeners. We used an A-B-B-A test design and determined if sound source localization improves when the device delay mismatch is reduced by delaying the CI stimulation by the HA processing delay (τ HA ). Results revealed that every subject in our group of nine bimodal listeners benefited from the approach. The root-mean-square error of sound localization improved significantly from 52.6° to 37.9°. The signed bias also improved significantly from 25.2° to 10.5°, with positive values indicating a bias toward the CI. Furthermore, two other delay values (τ HA –1 ms and τ HA +1 ms) were applied, and with the latter value, the signed bias was further reduced in some test subjects. We conclude that sound source localization accuracy in bimodal listeners improves instantaneously and sustainably when the device delay mismatch is reduced.
Bei bimodaler Cochlea-Implantat-/Hörgerät-Versorgung kann es aufgrund seitenverschiedener Signalverarbeitung zu einer zeitlich versetzten Stimulation der beiden Modalitäten kommen. Jüngste Studien haben gezeigt, dass durch zeitlichen Abgleich der Modalitäten die Schalllokalisation bei bimodaler Versorgung verbessert werden kann. Um solch einen Abgleich vornehmen zu können, ist die messtechnische Bestimmung der Durchlaufzeit von Hörgeräten erforderlich. Kommerziell verfügbare Hörgerätemessboxen können diese Werte häufig liefern. Die dazu verwendete Signalverarbeitung wird dabei aber oft nicht vollständig offengelegt. In dieser Arbeit wird ein alternativer und nachvollziehbarer Ansatz zum Design eines simplen Messaufbaus basierend auf einem Arduino DUE Mikrocontroller-Board vorgestellt. Hierzu wurde ein Messtisch im 3D-Druck gefertigt, auf welchem Hörgeräte über einen 2-ccm-Kuppler an ein Messmikrofon angeschlossen werden können. Über einen Latenzvergleich mit dem simultan erfassten Signal eines Referenzmikrofons kann die Durchlaufzeit von Hörgeräten bestimmt werden. Frequenzspezifische Durchlaufzeiten werden mittels einer Kreuzkorrelation zwischen Ziel- und Referenzsignal errechnet. Aufnahme, Ausgabe und Speicherung der Signale erfolgt über einen ATMEL SAM3X8E Mikrocontroller, welcher auf dem Arduino DUE-Board verbaut ist. Über eigens entworfene elektronische Schaltungen werden die Mikrofone und der verwendete Lautsprecher angesteuert. Nach Abschluss einer Messung (Messdauer ca. 5 s) werden die Messdaten seriell an einen PC übertragen, auf dem die Datenauswertung mittels MATLAB erfolgt. Erste Validierungen zeigten eine hohe Stabilität der Messergebnisse mit sehr geringen Standardabweichungen im Bereich weniger Mikrosekunden für Pegel zwischen 50 und 75 dB (A). Der Messaufbau wird in laufenden Studien zur Quantifizierung der Durchlaufzeit von Hörgeräten verwendet.
Lean und ERP - Synergie oder Widerspruch? Ein neuer Ansatz zur Steigerung der Unternehmenseffizienz
(2015)
Eine erfolgreiche Zusammenführung der Vorteile von ERP-Systemen mit den Vorzügen des Lean-Ansatzes kann zur Erschließung eines erheblichen Verbesserungspotenzials und damit zu signifikanten Wettbewerbsvorteilen einer Unternehmung führen. Da dieser Ansatz in der Praxis häufig kritisiert und bisher kaum adäquat verfolgt wird, zielt dieser Beitrag darauf ab, einen innovativen Lösungsweg vorzustellen, welcher nicht nur theoretisch, sondern auch anhand eines ERP-Einführungsprojekts in einem KMU empirisch aufzeigt, dass Lean und ERP nutzbringend miteinander kombiniert werden können und sollten.
Ripple: Overview and Outlook
(2015)
In this paper we integrate the ideas of network coding and relays into an existing practical network architecture used in a wireless network scenario. Specifically, we use the COPE architecture to test our ideas. Since previous works have focused on the communication aspect at the physical layer level, we attempt to take it one step further by including the MAC layer. Our idea is based on information theoretic concepts developed by Shannon in order to reliably apply network coding to increase the net throughput.
Experimental Investigation of the Air Exchange Effectiveness of Push-Pull Ventilation Devices
(2020)
The increasing installation numbers of ventilation units in residential buildings are driven by legal objectives to improve their energy efficiency. The dimensioning of a ventilation system for nearly zero energy buildings is usually based on the air flow rate desired by the clients or requested by technical regulations. However, this does not necessarily lead to a system actually able to renew the air volume of the living space effectively. In recent years decentralised systems with an alternating operation mode and fairly good energy efficiencies entered the market and following question was raised: “Does this operation mode allow an efficient air renewal?” This question can be answered experimentally by performing a tracer gas analysis. In the presented study, a total of 15 preliminary tests are carried out in a climatic chamber representing a single room equipped with two push-pull devices. The tests include summer, winter and isothermal supply air conditions since this parameter variation is missing till now for push-pull devices. Further investigations are dedicated to the effect of thermal convection due to human heat dissipation on the room air flow. In dependence on these boundary conditions, the determined air exchange efficiency varies, lagging behind the expected range 0.5 < εa < 1 in almost all cases, indicating insufficient air exchange including short-circuiting. Local air exchange values suggest inhomogeneous air renewal depending on the distance to the indoor apertures as well as the temperature gradients between in- and outdoor. The tested measurement set-up is applicable for field measurements.
Gas adsorption studies of CO2 and N2 in spatially aligned double-walled carbon nanotube arrays
(2013)
The suffix-free-prefix-free hash function construction and its indifferentiability security analysis
(2012)
In this paper, we observe that in the seminal work on indifferentiability analysis of iterated hash functions by Coron et al. and in subsequent works, the initial value (IV) of hash functions is fixed. In addition, these indifferentiability results do not depend on the Merkle–Damgård (MD) strengthening in the padding functionality of the hash functions. We propose a generic n-bit-iterated hash function framework based on an n-bit compression function called suffix-free-prefix-free (SFPF) that works for arbitrary IVs and does not possess MD strengthening. We formally prove that SFPF is indifferentiable from a random oracle (RO) when the compression function is viewed as a fixed input-length random oracle (FIL-RO). We show that some hash function constructions proposed in the literature fit in the SFPF framework while others that do not fit in this framework are not indifferentiable from a RO. We also show that the SFPF hash function framework with the provision of MD strengthening generalizes any n-bit-iterated hash function based on an n-bit compression function and with an n-bit chaining value that is proven indifferentiable from a RO.
Um Simulationen schnell und kostengünstig sowie ergebnisträchtig durchzuführen, bedarf es einer sorgfältigen Vorbereitung. Der Artikel befaßt sich mit dem automatischen Ablauf einer Simulationstudie zum Materilafluß und erläutert die im Ablauf notwendigen Beiträge der Anwender. In den Einzelheiten wird über die automatische Vorgehensweise und Anwendung der Standard-Simulationsmodelle (SSM) sowie spezieller Simulationsmodule (SimDBC) berichtet. Entscheidend für eine breitere Anwendung von Simulationswerkzeugen ist die einfache Handhabung und leicht verständliche Definition der zu untersuchenden Szenarien.
Since their dawning, space communications have been among the strongest driving applications for the development of error correcting codes. Indeed, space-to-Earth telemetry (TM) links have extensively exploited advanced coding schemes, from convolutional codes to Reed-Solomon codes (also in concatenated form) and, more recently, from turbo codes to low-density parity-check (LDPC) codes. The efficiency of these schemes has been extensively proved in several papers and reports. The situation is a bit different for Earth-to-space telecommand (TC) links. Space TCs must reliably convey control information as well as software patches from Earth control centers to scientific payload instruments and engineering equipment onboard (O/B) spacecraft. The success of a mission may be compromised because of an error corrupting a TC message: a detected error causing no execution or, even worse, an undetected error causing a wrong execution. This imposes strict constraints on the maximum acceptable detected and undetected error rates.
The three lines of defense model (TLoD) aims to provide a simple and effective way to improve coordination and enhance communications on risk management and control by clarifying the essential roles and duties of different governance functions. Without effective coordination of these governance functions, work can be duplicated or key risks may be missed or misjudged. To address these challenges, professional standards recommend that the chief audit executive (CAE) coordinates activities with other internal and external governance stakeholders (assurance providers). We consider survey responses from 415 CAEs from Austria, Germany, and Switzerland to analyze determinants that help to implement the TLoD without any challenges and to explore the extent of (coordination) challenges between the internal audit function and the respective governance stakeholders. Our results show a great variance in the extent of coordination challenges dependent on different determinants and the respective governance stakeholder.
Crowdinvesting als alternative Unternehmensfinanzierung - Grundlagen und Marktdaten in Deutschland
(2015)
Interne Revision: Anforderungen an die Wirksamkeit – ein Vergleich von IDW EPS 983 und MaRisk
(2017)
A two-dimensional single-phase model is developed for the steady-state and transient analysis of polymer electrolyte membrane fuel cells (PEMFC). Based on diluted and concentrated solution theories, viscous flow is introduced into a phenomenological multi-component modeling framework in the membrane. Characteristic variables related to the water uptake are discussed. A Butler–Volmer formulation of the current-overpotential relationship is developed based on an elementary mechanism of electrochemical oxygen reduction. Validated by using published V–I experiments, the model is then used to analyze the effects of operating conditions on current output and water management, especially net water transport coefficient along the channel. For a power PEMFC, the long-channel configuration is helpful for internal humidification and anode water removal, operating in counterflow mode with proper gas flow rate and humidity. In time domain, a typical transient process with closed anode is also investigated.
The state-of-the-art electrochemical impedance spectroscopy (EIS) calculations have not yet started from fully multi-dimensional modeling. For a polymer electrolyte membrane fuel cell (PEMFC) with long flow channel, the impedance plot shows a multi-arc characteristic and some impedance arcs could merge. By using a step excitation/Fourier transform algorithm, an EIS simulation is implemented for the first time based on the full 2D PEMFC model presented in the first part of this work. All the dominant transient behaviors are able to be captured. A novel methodology called ‘configuration of system dynamics’, which is suitable for any electrochemical system, is then developed to resolve the physical meaning of the impedance spectra. In addition to the high-frequency arc due to charge transfer, the Nyquist plots contain additional medium/low-frequency arcs due to mass transfer in the diffusion layers and along the channel, as well as a low-frequency arc resulting from water transport in the membrane. In some case, the impedance spectra appear partly inductive due to water transport, which demonstrates the complexity of the water management of PEMFCs and the necessity of physics-based calculations.
Background: This paper presents a novel approach for a hand prosthesis consisting of a flexible, anthropomorphic, 3D-printed replacement hand combined with a commercially available motorized orthosis that allows gripping.
Methods: A 3D light scanner was used to produce a personalized replacement hand. The wrist of the replacement hand was printed of rigid material; the rest of the hand was printed of flexible material. A standard arm liner was used to enable the user’s arm stump to be connected to the replacement hand. With computer-aided design, two different concepts were developed for the scanned hand model: In the first concept, the replacement hand was attached to the arm liner with a screw. The second concept involved attaching with a commercially available fastening system; furthermore, a skeleton was designed that was located within the flexible part of the replacement hand.
Results: 3D-multi-material printing of the two different hands was unproblematic and inexpensive. The printed hands had approximately the weight of the real hand. When testing the replacement hands with the orthosis it was possible to prove a convincing everyday functionality. For example, it was possible to grip and lift a 1-L water bottle. In addition, a pen could be held, making writing possible.
Conclusions: This first proof-of-concept study encourages further testing with users.
This work provides a series of methane adsorption isotherms and breakthrough curves on one 5A zeolite and one activated carbon. Breakthrough curves of CH4 were obtained from dynamic column measurements at different temperature and pressure conditions for concentrations of 4.4 – 17.3 mol.‐% in H2/CH4 mixtures. A simple model was developed to simulate the curves using measured and calculated data inputs. The results show that the model predictions agree very well with the experiments.
The separation of nitrogen and methane from hydrogen-rich mixtures is systematically investigated on a recently developed binder-free zeolite 5A. For this adsorbent, the present work provides a series of experimental data on adsorption isotherms and breakthrough curves of nitrogen and methane, as well as their mixtures in hydrogen. Isotherms were measured at temperatures of 283–313 K and pressures of up to 1.0 MPa. Breakthrough curves of CH4, N2, and CH4/N2 in H2 were obtained at temperatures of 300–305 K and pressures ranging from 0.1 to 6.05 MPa with different feed concentrations. An LDF-based model was developed to predict breakthrough curves using measured and calculated data as inputs. The number of parameters and the use of correlations were restricted to focus on the importance of measured values. For the given assumptions, the results show that the model predictions agree satisfactorily with the experiments under the different operating conditions applied.
Regarding the importance of adsorptive removal of carbon monoxide from hydrogen-rich mixtures for novel applications (e.g. fuel cells), this work provides a series of experimental data on adsorption isotherms and breakthrough curves of carbon monoxide. Three recently developed 5A zeolites and one commercial activated carbon were used as adsorbents. Isotherms were measured gravimetrically at temperatures of 278–313 K and pressures up to 0.85 MPa. Breakthrough curves of CO were obtained from dynamic column measurements at temperatures of 298–301 K, pressures ranging from 0.1 MPa to ca. 6 MPa and concentrations of CO in H2/CO mixtures of 5–17.5 mol%. A simple mathematical model was developed to simulate breakthrough curves on adsorbent beds using measured and calculated data as inputs. The number of parameters and the use of correlations to evaluate them were restricted in order to focus the importance of measured values. For the given assumptions and simplifications, the results show that the model predictions agree satisfactorily with the experimental data at the different operating conditions applied.
As a basis for the evaluation of hydrogen storage by physisorption, adsorption isotherms of H2 were experimentally determined for several porous materials at 77 K and 298 K at pressures up to 15 MPa. Activated carbons and MOFs were studied as the most promising materials for this purpose. A noble focus was given on how to determine whether a material is feasible for hydrogen storage or not, dealing with an assessment method and the pitfalls and problems of determining the viability. For a quantitative evaluation of the feasibility of sorptive hydrogen storage in a general analysis, it is suggested to compare the stored amount in a theoretical tank filled with adsorbents to the amount of hydrogen stored in the same tank without adsorbents. According to our results, an “ideal” sorbent for hydrogen storage at 77 K is calculated to exhibit a specific surface area of >2580 m2 g−1 and a micropore volume of >1.58 cm3 g−1.
Im Rahmen einer Master Thesis wurde ausgehend von einem vorhandenen System On Chip Design, welches eingehende EKG-Datensignale verarbeitet, das bestehende System so erweitert dass es komplett über den standardisierten SPI-Bus steuerbar und auslesbar ist.
In der genossenschaftlichen FinanzGruppe werden neben Verbundunternehmen wie zum Beispiel der DZ Bank rund 45 bis 50 Genossenschaftsbanken von der künftigen Berichtspflicht nach der sogenannten CSR-Richtlinie betroffen sein. Dieser Artikel gibt Hinweise zu Auswirkungen der neuen Gesetzeslage, aber auch zu Chancen und Potenzialen. Diskutiert wird insbesondere, was das neue Gesetz bzw. der Regierungsentwurf von 2016 besagt, und was die Vorgaben konkret für Genossenschaftsbanken bedeuten. Der Beitrag diskutiert zudem Synergien, Chancen und Potenziale: Das Thema Nachhaltigkeit kann wertvolle Impulse für eine zielgerichtete Weiterentwicklung des eigenen Geschäftsmodells bieten, beispielsweise wie neue Kundengruppen und/oder neue Ertragspotenziale mit Hilfe von neuen Produkten beziehungsweise Geschäftsfeldern erschlossen werden können.
Der demografische Wandel wird betriebs- und volkswirtschaftlich vielfach mit dem Fachkräftemangel in Zusammenhang gebracht. Diese Sichtweise scheint jedoch verkürzt. Die Alterung der Gesellschaft wird die Geschäftsmodelle von Finanzdienstleistern in den nächsten Jahren auf den Prüfstand stellen. Dies gilt vor allem für regionalverankerte Institute. Ein frühzeitiges Gegensteuern auf den Ebenen Strategie, Kunden- und Mitgliederstruktur, Produktportfolio sowie Marketing und Vertrieb kann jedoch den Markterfolg langfristig sichern.
Sind Mitglieder eine aussterbende Spezies? Der demografische Wandel zeigt dringenden Handlungsbedarf
(2012)
Eine Mitte November veröffentlichte EU-Richtlinie sieht vor, dass ab 2017 Unternehmen mit durchschnittlich mehr als 500 Mitarbeitern bestimmte Nachhaltigkeitsangaben im Lagebericht veröffentlichen müssen. Auf den ersten Blick scheint hier weiterer administrativer Ballast für die wenigen betroffenen Genossenschaftsbanken zu entstehen. Doch daraus ergeben sich für die Institute auch Chancen. Es lohnt sich zu prüfen, ob ein aktives Nachhaltigkeitsmanagement sinnvoll erscheint.
Nachhaltigkeit in der DNA
(2014)
Massive Umwälzungen im Marktumfeld, verstärkt durch disruptive Technologien, stellen viele Unternehmen vor die existenzielle Frage, wie sie ihr etabliertes Geschäftsmodell zukunftsfähig weiterentwickeln können beziehungsweise wie sie sich unter Umständen grundlegend neu aufstellen müssen. Volatilität, Unsicherheit, Komplexität und Ambiguität (kurz VUKA) sind in diesem Kontext jene ungünstigen Begleiterscheinungen, die auch genossenschaftliche Unternehmen beeinflussen. Die vielfältigen Herausforderungen im Unternehmensumfeld, wie beispielsweise ungünstige demografische Entwicklungen, eine zunehmende Urbanisierung bei steigendem Bedarf an regionaler Daseinsvorsorge, Wettbewerbsdruck durch neue Geschäftsmodelle und Konkurrenten infolge der Künstlichen Intelligenz beziehungsweise Digitalisierung – zum Beispiel durch FinTechs – bedingen die Suche nach Orientierung, nach einem strategischen Kompass sowohl für Politik, Wirtschaft und Gesellschaft.
Am Beispiel der kanadischen Metropole Vancouver zeigt sich, dass auch in Zeiten einer immer komplexer werdenden Welt Wirtschaftswachstum, Nachhaltigkeit und Lebenswert positiv korrelieren können und innerhalb weniger Jahrzehnte regional umsetzbar sind. Die Stadt setzt dabei überwiegend auf zentral gesteuerte Aktivitäten der „Vancouver Economic Comission“, die alle gesellschaftlichen und unternehmerischen Anspruchsgruppen auf der Basis werteorientierten Handelns konsequent das Ziel verfolgen lässt, Vancouver zu einer global anerkannten Stadt für innovatives, kreatives und nachhaltiges Business zu entwickeln. Das Streben Vancouvers weist dabei Parallelen zu genossenschaftlichen Wesensprinzipien sowie zu im deutschsprachigen Raum bereits existierenden Ansätzen genossenschaftlicher Innovationsökosysteme auf. Letztere haben bereits an verschiedenen Stellen bewiesen, dass sie das Potenzial haben in Zeiten komplexer Herausforderungen zukunftsfähige Lösungen für die Menschen in der Region gemeinschaftlich zu entwickeln. Gleichzeitig lassen sich mittels innovativer Produkte, Dienstleistungen und Geschäftsmodelle neue Ertragsquellen erschließen.
Strategen genossenschaftlicher oder kooperativer Banken und Unternehmen sollten nachfolgende Fragen bewegen:
• Was können deutsche Städte, Gemeinden und Regionen von Vancouver hinsichtlich des Aufbaus und der Gestaltung dynamischer Innovationsökosysteme lernen?
• Welche Rolle können Genossenschaften in Innovationsökosystemen spielen?
• Wie könnten die Innovationsprinzipien, -methoden und -formate in der jeweiligen Region erfolgversprechend eingesetzt werden?
Die Coronakrise hat weltweit das Wirtschafts- und Gesellschaftsleben in bisher ungekannter Weise verändert. Die ohnehin bereits komplexen Herausforderungen in Zeiten des Klimawandels sind damit noch gestiegen. Genossenschaftliche Innovationsökosysteme können Lösungsansätze für die gravierenden Veränderungen im unternehmerischen, kommunalen und gesellschaftlichen Umfeld schaffen.
In den vergangenen Jahren ist das technische Gas Schwefelhexafluorid (SF6) immer wieder Gegenstand von Diskussionen des Klimaschutzes und der technischen Notwendigkeit für den Betrieb von Schaltanlagen gewesen und wird dies wohl auch noch für längere Zeit bleiben. Das Gas, welches sich aus einem Schwefelatom und sechs Fluoratomen zusammensetzt, wird seit Ende der sechziger 1960er Jahre in Schaltanlagen der Mittel- und Hochspannung eingesetzt. So günstig dessen Eigenschaften im technischen Einsatz auch sind, so klimaschädlich ist es beim Entweichen in die Atmosphäre. SF6 ist das Klimagas mit dem größten bekannten Treibhauspotenzial, es weist ein CO2-Äquivalent (GWP) von 23.900 und eine atmosphärische Lebensdauer von ca. 3.200 Jahren auf. Neben nur wenig verbliebenen Anwendungen in Industrie, Militär und Medizin kommt es heute hauptsächlich bei der elektrischen Energieversorgung als Isolier- und Lichtbogenlöschgas in Schaltanlagen von Übertragungs- und Verteilnetzen zum Einsatz. Grund genug die technische Notwendigkeit, mögliche Alternativen und Konsequenzen drohender Verbote zu diskutieren. In diesem Artikel werden zunächst die Grundlagen moderner SF6- Hochspannungsschaltanlagen vorgestellt, die Klimabelastung durch entweichendes SF6 evaluiert, ein Überblick über den Stand der Forschung gegeben und mögliche Konsequenzen eines Verbotes von Schwefelhexafluorid in der Energieversorgung diskutiert.
Background: Increasing awareness of the importance of evidence-based medicine is demonstrated not only by an increasing number of articles addressing it but also by a specialty-wide evidence-based medicine initiative. The authors critically analyzed the quality of reporting of randomized controlled trials published in this Journal over a 21-year period (1990 to 2010).
Methods: A hand search was conducted, including all issues of Plastic and Reconstructive Surgery from January of 1990 to December of 2010. All randomized controlled trials published during this time period were identified with the Cochrane decision tree for identification of randomized controlled trials. To assess the quality of reporting, a modification of the checklist of the Consolidated Standard of Reporting Trials Statement was used.
Results: Of 7121 original articles published from 1990 to 2010 in the Journal, 159 (2.23 percent) met the Cochrane criteria. A significant increase in the absolute number of randomized controlled trials was seen over the study period (p < 0.0001). The median quality of these trials from 1990 to 2010 was "fair," with a trend toward improved quality of reporting over time (p = 0.127).
Conclusions: A favorable trend is seen with respect to an increased number of published randomized controlled trials in Plastic and Reconstructive Surgery. Adherence to standard reporting guidelines is recommended, however, to further improve the quality of reporting. Consideration may be given to providing information regarding the quality of reporting in addition to the "level of evidence pyramid," thus facilitating critical appraisal.
It is the purpose of this paper to address ethical issues concerning the development and application of Assistive Technology at Workplaces (ATW). We shall give a concrete technical concept how such technology might be constructed and propose eight technical functions it should adopt in order to serve its purpose. Then, we discuss the normative questions why one should use ATW, and by what means. We argue that ATW is good to the extent that it ensures social inclusion and consider four normative domains in which its worth might consists in. In addition, we insist that ATW must satisfy two requirements of good workplaces, which we specify as (a) an exploitation restraint and (b) a duty of care.
Accelerated transformation of the society and industry through digi-talization, artificial intelligence and other emerging technologies has intensified the need for university graduates that are capable of rapidly finding breakthrough solutions to complex problems, and can successfully implement innovation con-cepts. However, there are only few universities making significant efforts to com-prehensively incorporate creative and systematic tools of TRIZ (theory of in-ventive problem solving) and KBI (knowledge-based innovation) into their de-gree structure. Engineering curricula offer little room for enhancing creativity and inventiveness by means of discipline‐specific subjects. Moreover, many ed-ucators mistakenly believe that students are either inherently creative, or will in-evitably obtain adequate problem-solving skills as a result of their university study. This paper discusses challenges of intelligent integration of TRIZ and KBI into university curricula. It advocates the need for development of standard guidelines and best-practice recommendations in order to facilitate sustainable education of ambitious, talented, and inventive specialists. Reflections of educa-tors that teach TRIZ and KBI to students from mechanical, electrical, process engineering, and business administration are presented.
Structured Innovation with TRIZ in Science and Industry - Creating Value for Customers and Society
(2016)
The design of control systems of concentrator photovoltaic power plants will be more challenging in the future. Reasons are cost pressure, the increasing size of power plants, and new applications for operation, monitoring and maintenance required by grid operators, manufacturers and plant operators. Concepts and products for fixed-mounted photovoltaic can only partly be adapted since control systems for concentrator photovoltaic are considerable more complex due to the required high accurate sun-tracking. In order to assure reliable operation during a lifetime of more than 20 years, robustness of the control system is one crucial design criteria. This work considers common engineering technics for robustness, safety and security. Potential failures of the control system are identified and their effects are analyzed. Different attack scenarios are investigated. Outcomes are design criteria that encounter both: failures of system components and malicious attacks on the control system of future concentrator photovoltaic power plants. Such design criteria are a transparent state management through all system layers, self-tests and update capabilities for security concerns. The findings enable future research to develop a more robust and secure control system for concentrator photovoltaics when implementing new functionalities in the next generation.
The communication system of a large-scale concentrator photovoltaic power plant is very challenging. Manufacturers are building power plants having thousands of sun tracking systems equipped with communication and distributed over a wide area. Research is necessary to build a scalable communication system enabling modern control strategies. This poster abstract describes the ongoing work on the development of a simulation model of such power plants in OMNeT++. The model uses the INET Framework to build a communication network based on Ethernet. First results and problems of timing and data transmission experiments are outlined. The model enables research on new communication and control approaches to improve functionality and efficiency of power plants based on concentrator photovoltaic technology.
The design of control systems in large-scale CPV power plants will be more challenging in the future. Reasons are the increasing size of power plants, the requirements of grid operators, new functions, and new technological trends in industrial automation or communication technology. Concepts and products from fixed-mounted PV can only partly be adopted since control systems for sun-tracking installations are considerable more complex due to the higher quantity of controllable entities. The objective of this paper is to deliver design considerations for next generation control systems. Therefore, the work identifies new applications of future control systems categorized into operation, monitoring and maintenance domains. The key-requirements of the technical system and the application layer are identified. In the resulting section, new strategies such as a more decentralized architecture are proposed and design criteria are derived. The contribution of this paper should allow manufacturers and research institutes to consider the design criteria in current development and to place further research on new functions and control strategies precisely.
The formation and analysis of ten microporous triazolyl isophthalate based MOFs, including nine isomorphous and one isostructural compound is presented. The compounds 1 M – 3 M with the general formula [ M ( R 1 - R 2 - trz - ia ) ] ∞ 3 ·x H 2 O (M 2+ = Co 2+ , Cu 2+ , Zn 2+ , Cd 2+ ; R 1 = H, Me; R 2 = 2py, 2pym, prz (2py = 2-pyridinyle; 2pym = 2-pyrimidinyle; prz = pyrazinyle)) crystallize with rtl topology. They are available as single crystals and also easily accessible in a multi-gram scale via refluxing the metal salts and the protonated ligands in a solvent. Their isomorphous structures facilitate the synthesis of heteronuclear MOFs; in case of 2 M , Co 2+ ions could be gradually substituted by Cu 2+ ions. The Co 2+ :Cu 2+ ratios were determined by ICP-OES spectroscopy, the distribution of Co 2+ and Cu 2+ in the crystalline samples are investigated by SEM-EDX analysis leading to the conclusions that Cu 2+ is more favorably incorporated into the framework compared to Co 2+ and, moreover, that the distribution of the two metal ions between the crystals and within the crystals is inhomogeneous if the crystals were grown slowly. The various compositions of the heteronuclear materials lead to different colors and the sorption properties for CO 2 and N 2 are dependent on the integrated metal ions.
Fast charging of lithium-ion batteries remains one of the most delicate challenges for the automotive industry, being seriously affected by the formation of lithium metal in the negative electrode. Here we present a physicochemical pseudo-3D model that explicitly includes the plating reaction as side reaction running in parallel to the main intercalation reaction. The thermodynamics of the plating reaction are modeled depending on temperature and ion concentration, which differs from the often-used assumption of a constant plating condition of 0 V anode potential. The reaction kinetics are described with an Arrhenius-type rate law parameterized from an extensive literature research. Re-intercalation of plated lithium was modeled to take place either via reverse plating (solution-mediated) or via an explicit interfacial reaction (surface-mediated). At low temperatures not only the main processes (intercalation and solid-state diffusion) become slow, but also the plating reaction itself becomes slower. Using this model, we are able to predict typical macroscopic experimental observables that are indicative of plating, that is, a voltage plateau during discharge and a voltage drop upon temperature increase. A spatiotemporal analysis of the internal cell states allows a quantitative insight into the competition between intercalation and plating. Finally, we calculate operation maps over a wide range of C-rates and temperatures that allow to assess plating propensity as function of operating condition.
Passive hybridization refers to a parallel connection of photovoltaic and battery cells on the direct current level without any active controllers or inverters. We present the first study of a lithium-ion battery cell connected in parallel to a string of four or five serially-connected photovoltaic cells. Experimental investigations were performed using a modified commercial photovoltaic module and a lithium titanate battery pouch cell, representing an overall 41.7 W-peak (photovoltaic)/36.8 W-hour (battery) passive hybrid system. Systematic and detailed monitoring of this system over periods of several days with different load scenarios was carried out. A scaled dynamic synthetic load representing a typical profile of a single-family house was successfully supplied with 100 % self-sufficiency over a period of two days. The system shows dynamic, fully passive self-regulation without maximum power point tracking and without battery management system. The feasibility of a photovoltaic/lithium-ion battery passive hybrid system could therefore be demonstrated.
Die Erfindung betrifft eine Photovoltaik-Stromversorgungsvorrichtung, insbesondere vom öffentlichen Stromnetz unabhängige Photovoltaik-Stromversorgungsvorrichtung, mit einem positiven (204) und einem negativen (206) Lastanschluss für den Anschluss einer elektrischen Last, mit einer Mehrzahl von photovoltaischen Zellen (104) und einer wiederaufladbaren Batterie (5), welche wenigstens zwei in Serie geschaltete Batteriezellen (112) umfasst. Nach der Erfindung sind die photovoltaischen Zellen (104) zu einer der Anzahl der Batteriezellen (112) entsprechenden Anzahl von seriell verbundenen Teilstrings (108) verschaltet und jeder Teilstring (108) ist mit einem positiven Teilstringanschluss mit einem Pluspol und mit einem negativen Teilstringanschluss mit einem Minuspol einer zugeordneten Batteriezelle (112) oder mehreren zugeordneten parallel geschalteten Batteriezellen (112) verbunden. Dabei kann jeder Teilstring (108) zwischen dem positiven und negativen Teilstringanschluss eine maximale Leerlaufspannung erzeugen, die kleiner oder gleich einer vorgegebenen Ladeschlussspannung der zugeordneten Batteriezelle (112) oder der zugeordneten parallel geschalteten Batteriezellen (112) ist. Weiterhin betrifft die Erfindung eine Schaltungsanordnung zum Laden einer wiederaufladbaren Batterie, die zur Realisierung einer derartigen Photovoltaik-Stromversorgungsvorrichtung geeignet ist.
Simulation-based degradation assessment of lithium-ion batteries in a hybrid electric vehicle
(2017)
Covert and Side-Channels have been known for a long time due to their versatile forms of appearance. For nearly every technical improvement or change in technology, such channels have been (re-)created or known methods have been adapted. For example the introduction of hyperthreading technology has introduced new possibilities for covert communication between malicious processes because they can now share the arithmetic logical unit (ALU) as well as the L1 and L2 cache which enables establishing multiple covert channels. Even virtualization which is known for its isolation of multiple machines is prone to covert and side-channel attacks due to the sharing of resources. Therefore itis not surprising that cloud computing is not immune to this kind of attacks. Even more, cloud computing with multiple, possibly competing users or customers using the same shared resources may elevate the risk of unwanted communication. In such a setting the ”air gap” between physical servers and networks disappears and only the means of isolation and virtual separation serve as a barrier between adversary and victim. In the work at hand we will provide a survey on weak spots an adversary trying to exfiltrate private data from target virtual machines could exploit in a cloud environment. We will evaluate the feasibility of example attacks and point out possible mitigation solutions if they exist.
Several cloud schedulers have been proposed in the literature with different optimization goals such as reducing power consumption, reducing the overall operational costs or decreasing response times. A less common goal is to enhance the system security by applying specific scheduling decisions. The security risk of covert channels is known for quite some time, but is now back in the focus of research because of the multitenant nature of cloud computing and the co-residency of several per-tenant virtual machines on the same physical machine. Especially several cache covert channels have been identified that aim to bypass a cloud infrastructure's sandboxing mechanism. For instance, cache covert channels like the one proposed by Xu et. al. use the idealistic scenario with two alternately running colluding processes in different VMs accessing the cache to transfer bits by measuring cache access time. Therefore, in this paper we present a cascaded cloud scheduler coined C 3 -Sched aiming at mitigating the threat of a leakage of customers data via cache covert channels by preventing processes to access cache lines alternately. At the same time we aim at maintaining the cloud performance and minimizing the global scheduling overhead.
Covert channels have been known for a long time because of their versatile forms of appearance. For nearly every technical improvement or change in technology, such channels have been (re-)created or known methods have been adapted. For example, the introduction of hyperthreading technology has introduced new possibilities for covert communication between malicious processes because they can now share the arithmetic logical unit as well as the L1 and L2 caches, which enable establishing multiple covert channels. Even virtualization, which is known for its isolation of multiple machines, is prone to covert- and side-channel attacks because of the sharing of resources. Therefore, it is not surprising that cloud computing is not immune to this kind of attacks. Moreover, cloud computing with multiple, possibly competing users or customers using the same shared resources may elevate the risk of illegitimate communication. In such a setting, the “air gap” between physical servers and networks disappears, and only the means of isolation and virtual separation serve as a barrier between adversary and victim. In the work at hand, we will provide a survey on vulnerable spots that an adversary could exploit trying to exfiltrate private data from target virtual machines through covert channels in a cloud environment. We will evaluate the feasibility of example attacks and point out proposed mitigation solutions in case they exist.
In this paper an RFID/NFC (ISO 15693 standard) based inductively powered passive SoC (system on chip) for biomedical applications is presented. A brief overview of the system design, layout techniques and verification method is dis-cussed here. The SoC includes an integrated 32 bit microcontroller, sensor interface circuit, analog to digital converter, integrated RAM, ROM and some other peripherals required for the complete passive operation. The entire chip is realized in CMOS 0.18 μm technology with a chip area of 1.52mm x 3.24 mm.