Ministry for Environment, Agriculture, Conservation and Consumer Protection
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Optical Power Supply for a Wireless Sensor Node
No full textIn diesem Beitrag wird die optische Energieversorgung für einen drahtlosen energieautarken Sensorknoten beschrieben. Ein Überblick über das System einschließlich Sensorknoten, Energieversorgung und Kommunikationstechnik wird gegeben. Die Funkübertragungsmethoden werden hinsichtlich des Stromverbrauchs untersucht, um Anforderungen an die Stromversorgung zu definieren. Basierend auf Charakterisierungsmessungen des Verhaltens verschiedener Arten von Solarzellen unter künstlichem Licht, werden zwei Designs von Sensorknotenprototypen vorgestellt. Die optische Energieversorgung und das Energy-Harvesting-System für die Demonstratoren werden detailliert dargestellt.This article describes the optical power supply for a wireless, self-powered sensor node. An overview of the system including sensor nodes, power supply and communication technology is provided. The radio transmission methods are examined in terms of power consumption to define power supply requirements. Based on characterization measurements of the behavior of different types of solar cells under artificial light, two designs of sensor node prototypes are presented. The optical power supply and the energy harvesting system for the demonstrators will be presented in detail
Ein Ansatz zur Gewährleistung der Maschinensicherheit im IIoT-Zeitalter
No full textThe Industrial Internet of Things (IIoT) promises to bring benefits for all parties, from the machine manufacturers and system integrators to the end users, through data analytics and intelligent machines enabled by increased connectivity. The connectivity, however, brings along the possibility of unauthorised intrusions, causing disturbances in production or intralogistic systems, or in the worst scenario, acting as unintended or malicious triggers for safety hazards. In this work, we present an approach for safety and security co-assurance for machinery. Current safety and security standardisation for industrial control systems and for machinery is discussed, as well as safety and security co-assessment methodology. On this basis, an updated machine lifecycle model and an approach for safety and security risk co-assessment and risk reduction is described. Initial results based on the approach are discussed for a mixed-criticality controller device currently under development.Das Industrial Internet of Things (IIoT) verspricht Vorteile für alle Beteiligten, von den Maschinenherstellern und Systemintegratoren bis hin zu den Endanwendern, durch Datenanalyse und intelligente Maschinen mit erhöhter Konnektivität. Die Konnektivität bringt jedoch die Möglichkeit des unbefugten Eindringens mit sich, wodurch Störungen in der Produktion oder in logistischen Systemen verursacht werden oder welches im schlimmsten Fall das unbeabsichtigte oder böswil-lige Auslösen von Sicherheitsrisiken bewirkt. In dieser Arbeit stellen wir einen Ansatz zur Sicherung von Maschinen, unter Berücksichtigung von Safety und Security, vor. Die aktuellen Sicherheitsnormen für industrielle Steuerungssysteme und für Maschinen werden ebenso erörtert wie die Methodik der Sicherheitsbeurteilung. Auf dieser Basis wird ein aktualisiertes Maschinenlebenszyklusmodell und ein Ansatz zur Bewertung und Reduzierung von Sicherheitsrisiken (Safety und Security) beschrieben. Erste Ergebnisse auf Basis des Ansatzes werden für eine in Entwicklung befindliche Mixed-Criticality-Steuerung diskutiert
Simulationsmodell für die Verifikation einer sicherheitsbezogenen Hubwerksteuerung
No full textDevelopment of safety-related control systems requires extensive testing to verify correct functionality of the developed system in all circumstances. In this work, a simulation model of a novel hoist concept is shown. The simulation model consists of a complete electromechanical model of the drivetrain, including the pole-changing induction motor, slipping clutch and the brake, coupled with a two-mass spring-damped model of the hoist, the load and the crane bridge. The simulation model enables model-assisted testing of a hoist supervision unit currently being developed as part of a research project. We discuss the taken approach to software testing using the developed model.Die Entwicklung von sicherheitsbezogenen Steuerungen erfordert umfangreiche Tests, um die korrekte Funktion des entwickelten Systems unter allen Umständen zu überprüfen. In dieser Arbeit wird ein Simulationsmodell eines neuartigen Hebezeugkonzepts gezeigt. Das Simulationsmodell besteht aus einem kompletten elektromechanischen Modell des Antriebsstrangs einschließlich polumschaltbarem Induktionsmotor, Rutschkupplung und Bremse, gekoppelt mit einem Zwei-Massen-Feder-Dämpfer-Modell des Hubwerks, der Last und der Kranbrücke. Das Simulationsmodell ermöglicht die modellgestützte Verifikation einer im Rahmen eines Forschungsprojektes entwickelten Hubwerksteuerung. Wir besprechen die Vorgehensweise beim Software-Testen anhand des entwickelten Modells
From Grexit to Brexit and back: Mediatisation of economy and the politics of fear in the Twitter discourses of the Prime Ministers of Greece and the UK
No full textEconomy talk as blaming strategy: Crisis framings in The Guardian news stories and recontextualisations in user comments during the Greek bailout referendum
No full textDidaktische E-Learning-Szenarien für die Hochschullehre
No full textE-Learning ist seit einigen Jahren fester Bestandteil der Hochschullehre. Trotzdem wird das Potenzial von E-Learning an deutschen Hochschulen nicht annähernd ausgeschöpft. Die Nutzung beschränkt sich häufig auf die Distribution von Materialien. Einerseits sind die Hochschulen aufgefordert, sich mit technologischen Innovationen und Entwicklungen zu beschäftigen und in die Lehre zu integrieren. Anderseits fehlt grundlegendes Wissen bei den Lehrenden darüber, in welchen Situationen und in welcher Form E-Learning in der Hochschullehre sinnvoll eingesetzt werden kann. Vor diesem Hintergrund werden in der vorliegenden Arbeit didaktische E-Learning-Szenarien für die Hochschullehre systematisch entwickelt
Sponsored Blog Content: What do the Regulations Say? And what do Bloggers Say?
No full textInfluencer marketing – the use of opinion leaders such as bloggers with many followers and readers to disseminate product messages – is gaining advertisers’ interest. This paper presents the law and self-regulative provisions concerning blog advertising in both Europe and the US and documents the actual practice of disclosing blog advertising: whether and if so how, bloggers disclose influences from advertisers, and how these disclosures align with the regulations in place. The Federal Trade Commission Act and related guides in the US, and self-regulative provisions in Europe urge advertisers and endorsers, such as bloggers, to disclose any commercial relationship. These disclosures should be clear and conspicuous because advertising to consumers should be recognizable as such. Although advertisers increasingly encourage bloggers to promote products, it is unclear whether bloggers comply with disclosure requirements. To test compliance with disclosure requirements, we performed a content analysis of 200 blog posts drawn from the top-20-ranked sites in the Netherlands and the United States. We found that 65% of the posts mention brands and products. Yet, only 15% of the blog posts provided some commercial sponsorship disclosure. To determine whether posts mentioning brands were organic, unsponsored endorsements, we made repeated attempts to contact authors. Of those that responded, most claimed that their writing was not sponsored, but a small number received remuneration and did not disclose it. Furthermore, among the disclosing bloggers, we found regular problems in their sponsorship disclosures: many only state ‘sponsored’ or ‘affiliated link’; only 1/3 stated the name of the actual sponsor; most require the users to “scroll down,”; and most are in the same font as ordinary text. Our findings raise several regulatory issues; namely, the need for more concrete guidance on disclosure format, and it highlights the difficulty of monitoring compliance with the existing provisions. In so doing, our findings also provide important input for the European Commission’s Regulatory Fitness and Performance exercise, which tackles, among others the Unfair Commercial Practice Directive
Combination of residual stresses and operational stresses in a crane wheel
No full textAuch bei Normgerecht dimensionierten Laufrädern an Portal- und Brückenkränen treten regelmäßig ähnliche Schäden an Radkränzen auf. Für die Festigkeitsberechnung nach Norm ist alleine die Betriebslast ausschlaggebend. Untersuchungen zeigen jedoch, dass Kranräder aus dem Fertigungsprozess bereits mit hohen Eigenspannungen vorbelastet sind. Die Vorliegende Arbeit kombiniert diesen Eigenspannungszustand analytisch und mittels FEM mit den Betriebslasten. Der dadurch errechnete Gesamtspannungszustand gibt Hinweise auf die Ursache der auftretenden Schadensmuster. Die errechneten Spannungen zeigen auch, dass dem Eigenspannungszustand des Rades in der Kranraddimensionierung auf jeden Fall Beachtung geschenkt werden sollte.Even with crane wheels of gantry cranes and overhead cranes complying to current EN standards, similar damages to wheel rims occur regularly. For design and stress analysis only the operating load is considered in the standards. Studies show, however, that crane wheels are already subject to high residual stresses from the production process. The present work combines this residual stress state analytically and by means of FEM with the operating loads. The calculated total stress state gives indications of the cause of the occurring damage patterns. The calculated stresses also show that attention should definitely be paid to the residual stress state in the crane wheel design process
“This Video is Unavailable”: Analyzing Copyright Takedown of User-Generated Content on YouTube
No full textWhat factors lead a copyright owner to request removal of potentially infringing user-generated content? So-called “notice-and-takedown” measures are provided in the United States under Section 512 of the U.S. Copyright Act (as amended by the Digital Millennium Copyright Act 1998) and enabled in the European Union under the Directive on Electronic Commerce (2000/31/EC). While the combination of limiting liability (“safe harbor”) and notice-and-takedown procedures was originally conceived as a means of balancing innovation with the interests of rightholders, there has been limited empirical study regarding their effects. This research investigates, for the first time, the factors that motivate takedown of user-generated content by copyright owners. We study takedowns within an original dataset of 1,839 YouTube music video parodies observed between January 2012 and December 2016. We find an overall rate of takedowns within the sample of 32.9% across the 4-year period. We use a Cox proportional hazards model to investigate propositions from rightholder groups about the factors that motivate takedowns: these include concerns about commercial substitution; artistic/moral concerns; cultural differences between firms; and YouTube uploader practices. The main finding is that policy concerns frequently raised by rightholders are not associated with statistically significant patterns of action. For example, the potential for reputational harm from parodic use does not appear to predict takedown behavior. Nor does commercial popularity of the original music track trigger a systematic response from rightholders. Instead, music genre and production values emerge as significant factors. We suggest that evolving policy on intermediary liability - for example with respect to imposing filtering systems (automatically ensuring “stay-down” of potentially infringing content) - should be carefully evaluated against evidence of actual behavior, which this study shows may differ materially from stated policy positions
