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Auflistung nach Schlagwort "peer-to-peer"

1 - 7 von 7
  • Zeitschriftenartikel
    Das ökonomische kalkül eines anbieters von mediendateien bei filesharing-diensten
    (Wirtschaftsinformatik: Vol. 45, No. 3, 2003) Becker, Jan U.; Clement, Michel
    Filesharing has recently proved to be one of the most controversial applications in the Internet. Millions of users enjoy downloads of billions of media files such as songs or movies. But where do these files come from? While the economic rationale to download files is obvious, the rationale of individuals to actually share and therefore internalize the costs (i.e. the risk of being sued for copyright infringement) is not obvious. Consequently empirical studies have shown a large proportion of users not offering any but demanding files and therefore freeride on their peers.Nevertheless sharing can be rational. This article offers a theoretical base to explain sharing and proves that the users’ utility considerations depend heavily on the networks life cycle. The user’s utility of sharing decreases over time. In order to prevent the (theoretically) inevitable break-down of the filesharing network, the authors present strategies for filesharing networks to enhance the user’s willingness to share.
  • Zeitschriftenartikel
    Fault-tolerant data management in the gaston peer-to-peer file system
    (Wirtschaftsinformatik: Vol. 45, No. 3, 2003) Dynda, Vladimír; Rydlo, Pavel
    Gaston is a peer-to-peer large-scale file system designed to provide a fault-tolerant and highly available file service for a virtually unlimited number of users. Data management in Gaston disseminates and stores replicas of files on multiple machines to achieve the requested level of data availability and uses a dynamic tree-topology structure to connect replication schema members. We present generic algorithms for replication schema creation and maintenance according to file user requirements and autonomous constraints that are set on individual nodes. We also show specific data object structure as well as mechanisms for secure and efficient update propagation among replicas with data consistency control. Finally, we introduce a scalable and efficient technique improving fault-tolerance of the tree-topology structure connecting replicas.
  • Textdokument
    Gossip protocol approach for a decentralized energy market with OPC UA client-server communication
    (INFORMATIK 2020, 2021) Schindler, Josef; Tellabi, Asmaa; Waedt, Karl
    Gossiping is a well-researched protocol that enables decentralized information sharing. Being comparable to viruses spreading in a biological population, such concepts of data sharing are also called epidemic protocol. Without wanting to be impious with respect to recent pandemics, we propose its usage to facilitate a peer-to-peer (P2P) market for sharing energy between flexible loads or generation units, respectively. Gossip algorithms have been proposed several times in the context of power sharing in transmission grids. Our main contribution is the integration of such scenario with OPC UA. Comprising security by design, good interoperability attributes, several, well-maintained stack implementations and a widespread usage in automation, it reveals to be an outstanding framework for the proposed use case that will be explained in the first sections. After describing underlying physical models and the setup scenario, we will compare the results of the scenario that was conducted on non-OPC UA modules and an OPC UA implementation. Mostly, the performance is questioned at the comparison, still some beneficial concepts of OPC UA can be highlighted in the conclusion: Security controls can be added to the system at the Application Layer where Attribute Based Access Control (ABAC) can be performed, which allows a fine granularity of privileges expressed for subjects (agents in the gossiping algorithms) and objects (energy related assets) via semi-formal security policies. Additionally, UA Discovery service allows for plug and play availability. Concluding, a framework for a very efficient large-area algorithm is presented here to be researched in further work.
  • Conference Paper 
    Lehrfilme einfach einfach machen – erfolgreiche Konzeptionierung von Peer-to-Peer Lehrfilmen
    (DELFI 2019, 2019) Pfennig, Anja; Maier-Rothe, Jörg
    Lehrfilme im Kontext der Hochschulausbildung setzen einen audiovisuellen Impuls, werden als probates Lernmedium eingesetzt und umfassen eine Vielzahl unterschiedlicher Lernmethoden. Weil Lehrfilme in der Grundlagenlehre Werkstofftechnik als begleitende Lernmittel eingesetzt werden, müssen sie inhaltlich einem auf die Kursinhalte zugeschnittenen hohen Qualitätsanspruch genügen. Wichtig bei der Erstellung der Lehrfilme ist die Beteiligung von Studierenden (Peer-to-Peer Ansatz). Ihre unmittelbare Nähe zum modernen Lernprozess und die Anforderungen an Lernbedürfnisse sind entscheidend für den späteren Lernerfolg. Der Lernerfolg wird auch durch die Bereitstellung unterschiedlicher Filmformate unterstützt. Im Folgenden werden aus persönlicher Erfahrung heraus niederschwellige, praktische Empfehlungen zur Umsetzung von „funktionierenden“ Lehrfilmen (keine Produktbewerbungen) gegeben und eine erste Bewertung des Einsatzes von Lehrfilmen in der Grundlagenlehre der Studieneingangsphase Maschinenbau vorgenommen.
  • Konferenzbeitrag
    Optimizing Distributed Test Generation
    (10th International Conferenceon Innovative Internet Community Systems (I2CS) – Jubilee Edition 2010 –, 2010) Gros-Désormeaux, Harry; Fouchal, Hacène; Hunel, Philippe
    This paper presents two optimizations of the master-slave paradigm which provides more robustness. The former uses a mobile master which randomly jumps from node to node in order to dispatch the bandwidth load during the application execution. The latter aims to fully decentralize the paradigm like peer-to-peer systems. We present and experiment our new schemes on an application dedicated to test generation used in protocol engineering. We show that they can help for unknown dynamic environments where no information is given about nodes configuration.
  • Zeitschriftenartikel
    Praxiserfahrungen bei der Einführung dezentraler Wissensmanagement-Lösungen
    (Wirtschaftsinformatik: Vol. 45, No. 3, 2003) Schmücker, Jörg; Müller, Wolfgang
    Efficient management of knowledge is a major success factor for corporations and organizations. Many corporations have started Knowledge Management initiatives with the goal to actively manage knowledge creation and flow. Apart from the necessary organizational changes they have tried to support the quest for knowledge with Knowledge-Management systems. Peer-to-peer systems offer a cost-efficient, user-friendly alternative to server-based knowledge management solutions. However, due to various reasons they have not gained significant market share. During our sales activities for Dinow, our distributed knowledge management system, we have encountered various reasons for the slow adoption of this promising technology. In addition to technological concerns, e.g. regarding security, we have found that psychological factors are very significant: the possibility of “free” information flow contradicts the rigid frameworks, policies, and procedures in most organizations. It is a common misconception that currently used technology, i.e. e-mail, protects against such unwanted information flow.
  • Zeitschriftenartikel
    Resource allocation in peer-to-peer networks
    (Wirtschaftsinformatik: Vol. 45, No. 3, 2003) Grothoff, Christian
    Resource allocation in peer-to-peer networks — An excess-based economic model This paper describes economic aspects of GNUnet, a peer-to-peer framework for anonymous distributed file-sharing. GNUnet is decentralized; all nodes are equal peers. In particular, there are no trusted entities in the network. This paper describes an economic model to perform resource allocation and defend against malicious participants in this context. The approach presented does not use credentials or payments; rather, it is based on trust. The design is much like that of a cooperative game in which peers take the role of players. Nodes must cooperate to achieve individual goals. In such a scenario, it is important to be able to distinguish between nodes exhibiting friendly behavior and those exhibiting malicious behavior. GNUnet aims to provide anonymity for its users. Its design makes it hard to link a transaction to the node where it originated from. While anonymity requirements make a global view of the end-points of a transaction infeasible, the local link-to-link messages can be fully authenticated. Our economic model is based entirely on this local view of the network and takes only local decisions.