139 research outputs found

    Semantic Plug & Play - Selbstbeschreibende Hardware für modulare Robotersysteme

    Get PDF
    Moderne Robotersysteme bestehen aus einer Vielzahl unterschiedlicher Sensoren und Aktuatoren, aus deren Zusammenwirken verschiedene Fähigkeiten entstehen und nutzbar gemacht werden. So kann ein Knickarmroboter über die koordinierte Ansteuerung mehrerer Motoren Gegenstände greifen, oder ein Quadrocopter über Sensoren seine Lage und Position bestimmen. Eine besondere Ausprägung bilden modulare Robotersysteme, in denen sich Sensoren und Aktuatoren dynamisch entfernen, austauschen oder hinzufügen lassen, wodurch auch die verfügbaren Fähigkeiten beeinflusst werden. Die Flexibilität modularer Robotersysteme wird jedoch durch deren eingeschränkte Kompatibilität begrenzt. So existieren zahlreiche proprietäre Systeme, die zwar eine einfache Verwendung ermöglichen aber nur auf eine begrenzte Menge an modularen Elementen zurückgreifen können. Open-Source-Projekte mit einer breiten Unterstützung im Hardwarebereich, wie bspw. die Arduino-Plattform, oder Softwareprojekte, wie das Robot Operating System (ROS) versuchen, eine eben solch breite Kompatibilität zu bieten, erfordern allerdings eine sehr ausführliche Dokumentation der Hardware für die Integration. Das zentrale Ergebnis dieser Dissertation ist ein Technologiestack (Semantic Plug & Play) für die einfache Dokumentation und Integration modularer Hardwareelemente durch Selbstbeschreibungsmechanismen. In vielen Anwendungen befindet sich die Dokumentation üblicherweise verteilt in Textdokumenten, Onlineinhalten und Quellcodedokumentationen. In Semantic Plug & Play wird ein System basierend auf den Technologien des Semantic Web vorgestellt, das nicht nur eben solch vorhandene Dokumentationen vereinheitlicht und kollektiviert, sondern das auch durch eine maschinenlesbare Aufbereitung die Dokumentation in der Prozessdefinition verwendet werden kann. Eine in dieser Dissertation entwickelte Architektur bietet für die Prozessdefinition eine API für objektorientierte Programmiersprachen, in der abstrakte Fähigkeiten verwendet werden können. Mit einem besonderen Fokus auf zur Laufzeit rekonfigurierbare Systeme können damit Fähigkeiten über Anforderungen an aktuelle Hardwarekonfigurationen ausgedrückt werden. So ist es möglich, qualitative und quantitative Eigenschaften als Voraussetzung für Fähigkeiten zu definieren, die erst bei einem Wechsel modularer Hardwareelemente erfüllt werden. Diesem Prinzip folgend werden auch kombinierte Fähigkeiten unterstützt, die andere Fähigkeiten hardwareübergreifend für ihre intrinsische Ausführung nutzen. Für die Kapselung der Selbstbeschreibung auf einzelnen Hardwareelementen werden unterschiedliche Adapter in Semantic Plug & Play unterstützt, wie etwa Mikrocontroller oder X86- und ARM-Systeme. Semantic Plug & Play ermöglicht zudem eine Erweiterbarkeit zu ROS anhand unterschiedlicher Werkzeuge, die nicht nur eine hybride Nutzung erlauben, sondern auch die Komplexität mit modellgetriebenen Ansätzen beherrschbar machen. Die Flexibilität von Semantic Plug & Play wird in sechs Experimenten anhand unterschiedlicher Hardware illustriert. Alle Experimente adressieren dabei Problemstellungen einer übergeordneten Fallstudie, für die ein heterogener Quadrocopterschwarm in hochgradig dynamischen Szenarien eingesetzt und gezielt rekonfiguriert wird

    Tit-for-Token: fair rewards for moving data in decentralized storage networks

    Full text link
    Centralized data silos are not only becoming prohibitively expensive but also raise issues of data ownership and data availability. These developments are affecting the industry, researchers, and ultimately society in general. Decentralized storage solutions present a promising alternative. Furthermore, such systems can become a crucial layer for new paradigms of edge-centric computing and web3 applications. Decentralized storage solutions based on p2p networks can enable scalable and self-sustaining open-source infrastructures. However, like other p2p systems, they require well-designed incentive mechanisms for participating peers. These mechanisms should be not only effective but also fair in regard to individual participants. Even though several such systems have been studied in deployment, there is still a lack of systematic understanding regarding these issues. We investigate the interplay between incentive mechanisms, network characteristics, and fairness of peer rewards. In particular, we identify and evaluate three core and up-to-date reward mechanisms for moving data in p2p networks: distance-based payments, reciprocity, and time-limited free service. Distance-based payments are relevant since libp2p Kademlia, which enables distance-based algorithms for content lookup and retrieval, is part of various modern p2p systems. We base our model on the Swarm network that uses a combination of the three mechanisms and serves as inspiration for our Tit-for-Token model. We present our Tit-for-Token model and develop a tool to explore the behaviors of these payment mechanisms. Our evaluation provides novel insights into the functioning and interplay of these mechanisms and helps. Based on these insights, we propose modifications to these mechanisms that better address fairness concerns and outline improvement proposals for the Swarm network

    Nuevos modelos de plataformas descentralizadas basados en tecnología blockchain.

    Get PDF
    203 p.La tesis doctoral tiene como objetivo evaluar la influencia de la tecnología blockchain en los principales sectores económicos y los modelos de negocio de plataforma. Se han identificado los valores de negocio más demandados y se ha analizado la inversión en blockchain por parte de las empresas. Además, se ha desarrollado una taxonomía de los modelos de plataforma descentralizados, se ha realizado la identificación y evaluación de una muestra representativa de estas plataformas, y, por último, se ha propuesto una clasificación de los tres arquetipos de plataformas descentralizadas: hosted, federated y shared.Los resultados de la investigación han revelado que la tecnología blockchain está siendo adoptada a nivel global en todos los sectores, generando un impacto significativo en la industria. Se han identificado múltiples beneficios de esta tecnología en diferentes áreas y se ha proporcionado información detallada sobre la inversión en blockchain en distintas empresas y sectores.La tesis representa una valiosa contribución a la literatura, ya que brinda información real sobre la inversión en blockchain y caracteriza los modelos emergentes de plataformas descentralizadas. Estos resultados tienen el potencial de ayudar a los emprendedores a comprender mejor las posibilidades de la tecnología blockchain y a diseñar modelos de negocio innovadores y sostenibles

    Competencies of Modern Musician Entrepreneurs: The Role of Digitalization in the Music Industry

    Get PDF
    The culture creation industries are undergoing a period of accelerated digitization, globalization, and democratization. The 21st century music industry is bustling with lowered barriers to entry, increased knowledge sharing, and direct to consumer models which have resulted in a gold rush of entrepreneurial opportunities for musicians and increased competition to music firms and superstars. The music industry has been subject to innovative disruption providing valuable insight on the nuances of this paradigm shift for music entrepreneurs and scholars alike. Specifically, I explore competency factors in artist’s journey from musicians to entrepreneurs with successful self-managed careers. Employing Lazear’s Theory of Balanced Skills, I develop a survey instrument and 2x2 framework to discern between high and low levels of entrepreneurial business competencies and high or low levels of artistic competencies including creativity and musical competencies. I conclude by testing survey data from Prolific analyzing the relationships between business competencies, music, creative competencies, financial and non-financial performance, and the moderating role of digital adoption as measured by a questionnaire deployed to 232 active musicians between April and May of 2023. Results identify significant competencies across the 3 domains studied as well as positive and negative moderation by digital acceptance on the relationship between competencies and performance

    Measuring knowledge sharing processes through social network analysis within construction organisations

    Get PDF
    The construction industry is a knowledge intensive and information dependent industry. Organisations risk losing valuable knowledge, when the employees leave them. Therefore, construction organisations need to nurture opportunities to disseminate knowledge through strengthening knowledge-sharing networks. This study aimed at evaluating the formal and informal knowledge sharing methods in social networks within Australian construction organisations and identifying how knowledge sharing could be improved. Data were collected from two estimating teams in two case studies. The collected data through semi-structured interviews were analysed using UCINET, a Social Network Analysis (SNA) tool, and SNA measures. The findings revealed that one case study consisted of influencers, while the other demonstrated an optimal knowledge sharing structure in both formal and informal knowledge sharing methods. Social networks could vary based on the organisation as well as the individuals’ behaviour. Identifying networks with specific issues and taking steps to strengthen networks will enable to achieve optimum knowledge sharing processes. This research offers knowledge sharing good practices for construction organisations to optimise their knowledge sharing processes

    Music and Digital Media

    Get PDF
    Anthropology has neglected the study of music. Music and Digital Media shows how and why this should be redressed. It does so by enabling music to expand the horizons of digital anthropology, demonstrating how the field can build interdisciplinary links to music and sound studies, digital/media studies, and science and technology studies. Music and Digital Media is the first comparative ethnographic study of the impact of digital media on music worldwide. It offers a radical and lucid new theoretical framework for understanding digital media through music, showing that music is today where the promises and problems of the digital assume clamouring audibility. The book contains ten chapters, eight of which present comprehensive original ethnographies; they are bookended by an authoritative introduction and a comparative postlude. Five chapters address popular, folk, art and crossover musics in the global South and North, including Kenya, Argentina, India, Canada and the UK. Three chapters bring the digital experimentally to the fore, presenting pioneering ethnographies of anextra-legal peer-to-peer site and the streaming platform Spotify, a series of prominent internet-mediated music genres, and the first ethnography of a global software package, the interactive music platform Max. The book is unique in bringing ethnographic research on popular, folk, art and crossover musics from the global North and South into a comparative framework on a large scale, and creates an innovative new paradigm for comparative anthropology. It shows how music enlarges anthropology while demanding to be understood with reference to classic themes of anthropological theory. Praise for Music and Digital Media ‘Music and Digital Media is a groundbreaking update to our understandings of sound, media, digitization, and music. Truly transdisciplinary and transnational in scope, it innovates methodologically through new models for collaboration, multi-sited ethnography, and comparative work. It also offers an important defense of—and advancement of—theories of mediation.’ Jonathan Sterne, Communication Studies and Art History, McGill University 'Music and Digital Media is a nuanced exploration of the burgeoning digital music scene across both the global North and the global South. Ethnographically rich and theoretically sophisticated, this collection will become the new standard for this field.' Anna Tsing, Anthropology, University of California at Santa Cruz 'The global drama of music's digitisation elicits extreme responses – from catastrophe to piratical opportunism – but between them lie more nuanced perspectives. This timely, absolutely necessary collection applies anthropological understanding to a deliriously immersive field, bringing welcome clarity to complex processes whose impact is felt far beyond what we call music.' David Toop, London College of Communication, musician and writer ‘Spanning continents and academic disciplines, the rich ethnographies contained in Music and Digital Media makes it obligatory reading for anyone wishing to understand the complex, contradictory, and momentous effects that digitization is having on musical cultures.’ Eric Drott, Music, University of Texas, Austin ‘This superb collection, with an authoritative overview as its introduction, represents the state of the art in studies of the digitalisation of music. It is also a testament to what anthropology at its reflexive best can offer the rest of the social sciences and humanities.’ David Hesmondhalgh, Media and Communication, University of Leeds ‘This exciting volume forges new ground in the study of local conditions, institutions, and sounds of digital music in the Global South and North. The book’s planetary scope and its commitment to the “messiness” of ethnographic sites and concepts amplifies emergent configurations and meanings of music, the digital, and the aesthetic.’ Marina Peterson, Anthropology, University of Texas, Austi

    Music and Digital Media: A planetary anthropology

    Get PDF
    Anthropology has neglected the study of music. Music and Digital Media shows how and why this should be redressed. It does so by enabling music to expand the horizons of digital anthropology, demonstrating how the field can build interdisciplinary links to music and sound studies, digital/media studies, and science and technology studies. Music and Digital Media is the first comparative ethnographic study of the impact of digital media on music worldwide. It offers a radical and lucid new theoretical framework for understanding digital media through music, showing that music is today where the promises and problems of the digital assume clamouring audibility. The book contains ten chapters, eight of which present comprehensive original ethnographies; they are bookended by an authoritative introduction and a comparative postlude. Five chapters address popular, folk, art and crossover musics in the global South and North, including Kenya, Argentina, India, Canada and the UK. Three chapters bring the digital experimentally to the fore, presenting pioneering ethnographies of an extra-legal peer-to-peer site and the streaming platform Spotify, a series of prominent internet-mediated music genres, and the first ethnography of a global software package, the interactive music platform Max. The book is unique in bringing ethnographic research on popular, folk, art and crossover musics from the global North and South into a comparative framework on a large scale, and creates an innovative new paradigm for comparative anthropology. It shows how music enlarges anthropology while demanding to be understood with reference to classic themes of anthropological theory

    The 45th Australasian Universities Building Education Association Conference: Global Challenges in a Disrupted World: Smart, Sustainable and Resilient Approaches in the Built Environment, Conference Proceedings, 23 - 25 November 2022, Western Sydney University, Kingswood Campus, Sydney, Australia

    Get PDF
    This is the proceedings of the 45th Australasian Universities Building Education Association (AUBEA) conference which will be hosted by Western Sydney University in November 2022. The conference is organised by the School of Engineering, Design, and Built Environment in collaboration with the Centre for Smart Modern Construction, Western Sydney University. This year’s conference theme is “Global Challenges in a Disrupted World: Smart, Sustainable and Resilient Approaches in the Built Environment”, and expects to publish over a hundred double-blind peer review papers under the proceedings

    Empirical and Analytical Perspectives on the Robustness of Blockchain-related Peer-to-Peer Networks

    Get PDF
    Die Erfindung von Bitcoin hat ein großes Interesse an dezentralen Systemen geweckt. Eine häufige Zuschreibung an dezentrale Systeme ist dabei, dass eine Dezentralisierung automatisch zu einer höheren Sicherheit und Widerstandsfähigkeit gegenüber Angriffen führt. Diese Dissertation widmet sich dieser Zuschreibung, indem untersucht wird, ob dezentralisierte Anwendungen tatsächlich so robust sind. Dafür werden exemplarisch drei Systeme untersucht, die häufig als Komponenten in komplexen Blockchain-Anwendungen benutzt werden: Ethereum als Infrastruktur, IPFS zur verteilten Datenspeicherung und schließlich "Stablecoins" als Tokens mit Wertstabilität. Die Sicherheit und Robustheit dieser einzelnen Komponenten bestimmt maßgeblich die Sicherheit des Gesamtsystems in dem sie verwendet werden; darüber hinaus erlaubt der Fokus auf Komponenten Schlussfolgerungen über individuelle Anwendungen hinaus. Für die entsprechende Analyse bedient sich diese Arbeit einer empirisch motivierten, meist Netzwerklayer-basierten Perspektive -- angereichert mit einer ökonomischen im Kontext von Wertstabilen Tokens. Dieses empirische Verständnis ermöglicht es Aussagen über die inhärenten Eigenschaften der studierten Systeme zu treffen. Ein zentrales Ergebnis dieser Arbeit ist die Entdeckung und Demonstration einer "Eclipse-Attack" auf das Ethereum Overlay. Mittels eines solchen Angriffs kann ein Angreifer die Verbreitung von Transaktionen und Blöcken behindern und Netzwerkteilnehmer aus dem Overlay ausschließen. Des weiteren wird das IPFS-Netzwerk umfassend analysiert und kartografiert mithilfe (1) systematischer Crawls der DHT sowie (2) des Mitschneidens von Anfragenachrichten für Daten. Erkenntlich wird hierbei, dass die hybride Overlay-Struktur von IPFS Segen und Fluch zugleich ist, da das Gesamtsystem zwar robust gegen Angriffe ist, gleichzeitig aber eine umfassende Überwachung der Netzwerkteilnehmer ermöglicht wird. Im Rahmen der wertstabilen Kryptowährungen wird ein Klassifikations-Framework vorgestellt und auf aktuelle Entwicklungen im Gebiet der "Stablecoins" angewandt. Mit diesem Framework wird somit (1) der aktuelle Zustand der Stablecoin-Landschaft sortiert und (2) ein Mittel zur Verfügung gestellt, um auch zukünftige Designs einzuordnen und zu verstehen.The inception of Bitcoin has sparked a large interest in decentralized systems. In particular, popular narratives imply that decentralization automatically leads to a high security and resilience against attacks, even against powerful adversaries. In this thesis, we investigate whether these ascriptions are appropriate and if decentralized applications are as robust as they are made out to be. To this end, we exemplarily analyze three widely-used systems that function as building blocks for blockchain applications: Ethereum as basic infrastructure, IPFS for distributed storage and lastly "stablecoins" as tokens with a stable value. As reoccurring building blocks for decentralized applications these examples significantly determine the security and resilience of the overall application. Furthermore, focusing on these building blocks allows us to look past individual applications and focus on inherent systemic properties. The analysis is driven by a strong empirical, mostly network-layer based perspective; enriched with an economic point of view in the context of monetary stabilization. The resulting practical understanding allows us to delve into the systems' inherent properties. The fundamental results of this thesis include the demonstration of a network-layer Eclipse attack on the Ethereum overlay which can be leveraged to impede the delivery of transaction and blocks with dire consequences for applications built on top of Ethereum. Furthermore, we extensively map the IPFS network through (1) systematic crawling of its DHT, as well as (2) monitoring content requests. We show that while IPFS' hybrid overlay structure renders it quite robust against attacks, this virtue of the overlay is simultaneously a curse, as it allows for extensive monitoring of participating peers and the data they request. Lastly, we exchange the network-layer perspective for a mostly economic one in the context of monetary stabilization. We present a classification framework to (1) map out the stablecoin landscape and (2) provide means to pigeon-hole future system designs. With our work we not only scrutinize ascriptions attributed to decentral technologies; we also reached out to IPFS and Ethereum developers to discuss results and remedy potential attack vectors
    corecore