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  • 1.
    Armgarth, Astrid
    et al.
    RISE Research Institutes of Sweden, Digitala system, Smart hårdvara. Linköping University, Sweden.
    Pantzare, Sandra
    RISE Research Institutes of Sweden, Digitala system, Smart hårdvara.
    Arven, Patrik
    J2 Holding AB, Sweden.
    Lassnig, Roman
    RISE Research Institutes of Sweden.
    Jinno, Hiroaki
    RIKEN Center for Emergent Matter Science, Japan; University of Tokyo, Japan.
    Gabrielsson, Erik
    Linköping University, Sweden.
    Kifle, Yonatan
    Linköping University, Sweden.
    Cherian, Dennis
    Linköping University, Sweden.
    Arbring Sjöström, Theresia
    Linköping University, Sweden.
    Berthou, Gautier
    RISE Research Institutes of Sweden.
    Dowling, Jim
    RISE Research Institutes of Sweden, Digitala system, Datavetenskap. KTH Royal Institute of Technology, Sweden.
    Someya, Takao
    RIKEN Center for Emergent Matter Science, Japan; University of Tokyo, Japan.
    Wikner, Jacob
    Linköping University, Sweden.
    Gustafsson, Göran
    RISE Research Institutes of Sweden.
    Simon, Daniel
    Linköping University, Sweden.
    Berggren, Magnus
    Linköping University, Sweden.
    A digital nervous system aiming toward personalized IoT healthcare2021Inngår i: Scientific Reports, E-ISSN 2045-2322, Vol. 11, nr 1, artikkel-id 7757Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Body area networks (BANs), cloud computing, and machine learning are platforms that can potentially enable advanced healthcare outside the hospital. By applying distributed sensors and drug delivery devices on/in our body and connecting to such communication and decision-making technology, a system for remote diagnostics and therapy is achieved with additional autoregulation capabilities. Challenges with such autarchic on-body healthcare schemes relate to integrity and safety, and interfacing and transduction of electronic signals into biochemical signals, and vice versa. Here, we report a BAN, comprising flexible on-body organic bioelectronic sensors and actuators utilizing two parallel pathways for communication and decision-making. Data, recorded from strain sensors detecting body motion, are both securely transferred to the cloud for machine learning and improved decision-making, and sent through the body using a secure body-coupled communication protocol to auto-actuate delivery of neurotransmitters, all within seconds. We conclude that both highly stable and accurate sensing—from multiple sensors—are needed to enable robust decision making and limit the frequency of retraining. The holistic platform resembles the self-regulatory properties of the nervous system, i.e., the ability to sense, communicate, decide, and react accordingly, thus operating as a digital nervous system. © 2021, The Author(s).

  • 2. Biskupski, Bartosz
    et al.
    Dowling, Jim
    RISE - Research Institutes of Sweden, ICT, SICS.
    Sacha, Jan
    Properties and Mechanisms of Self-Organising MANET and P2P Systems2007Inngår i: ACM Transactions on Autonomous and Adaptive Systems, ISSN 1556-4665, E-ISSN 1556-4703, Vol. 2, nr 1, s. 34Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Despite the recent appearance of self-organizing distributed systems for Mobile Ad Hoc Networks (MANETs) and Peer-to-Peer (P2P) networks, specific theoretical aspects of both their properties and the mechanisms used to establish those properties have been largely overlooked. This has left many researchers confused as to what constitutes a self-organizing distributed system and without a vocabulary with which to discuss aspects of these systems. This article introduces an agent-based model of self-organizing MANET and P2P systems and shows how it is realised in three existing network systems. The model is based on concepts such as partial views, evaluation functions, system utility, feedback and decay. We review the three network systems, AntHocNet, SAMPLE, and Freenet, and show how they can achieve high scalability, robustness and adaptability to unpredictable changes in their environment, by using self-organizing mechanisms similar to those found in nature. They are designed to improve their operation in a dynamic, heterogeneous environment, enabling them to often demonstrate superior performance to state of the art distributed systems. This article is also addressed at researchers interested in gaining a general understanding of different mechanisms and properties of self-organization in distributed systems.

  • 3.
    Bux, Marc
    et al.
    Humboldt University of Berlin, Germany.
    Brandt, Jörgen
    Humboldt University of Berlin, Germany.
    Lipka, Carsten
    Humboldt University of Berlin, Germany.
    Hakimzadeh, Kamal
    KTH Royal Institute of Technology, Sweden.
    Dowling, Jim
    RISE - Research Institutes of Sweden (2017-2019), ICT, SICS. KTH Royal Institute of Technology, Sweden.
    Leser, Ulf
    Humboldt University of Berlin, Germany.
    SAASFEE: Scalable Scientific Workflow Execution Engine2015Inngår i: Proceedings of the VLDB Endowment, 2015, 10, Vol. 8, s. 1892-1903Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Across many fields of science, primary data sets like sensor read-outs, time series, and genomic sequences are analyzed by complex chains of specialized tools and scripts exchanging intermediate results in domain-specific file formats. Scientific workflow management systems (SWfMSs) support the development and execution of these tool chains by providing workflow specification languages, graphical editors, fault-tolerant execution engines, etc. However, many SWfMSs are not prepared to handle large data sets because of inadequate support for distributed computing. On the other hand, most SWfMSs that do support distributed computing only allow static task execution orders. We present SAASFEE, a SWfMS which runs arbitrarily complex workflows on Hadoop YARN. Workflows are specified in Cuneiform, a functional workflow language focusing on parallelization and easy integration of existing software. Cuneiform workflows are executed on Hi-WAY, a higher-level scheduler for running workflows on YARN. Distinct features of SAASFEE are the ability to execute iterative workflows, an adaptive task scheduler, re-executable provenance traces, and compatibility to selected other workflow systems. In the demonstration, we present all components of SAASFEE using real-life workflows from the field of genomics.

  • 4.
    Bux, Marc
    et al.
    Humboldt-Universität zu Berlin, Germany.
    Brandt, Jörgen
    Humboldt-Universität zu Berlin, Germany.
    Witt, Carl
    Humboldt-Universität zu Berlin, Germany.
    Dowling, Jim
    RISE - Research Institutes of Sweden, ICT, SICS.
    Leser, Ulf
    Humboldt-Universität zu Berlin, Germany.
    Hi-WAY: Execution of scientific workflows on hadoop YARN2017Inngår i: Advances in Database Technology - EDBT, OpenProceedings.org , 2017, s. 668-679Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Scientific workflows provide a means to model, execute, and exchange the increasingly complex analysis pipelines necessary for today’s data-driven science. However, existing scientific workflow management systems (SWfMSs) are often limited to a single workflow language and lack adequate support for large-scale data analysis. On the other hand, current distributed dataflow systems are based on a semi-structured data model, which makes integration of arbitrary tools cumbersome or forces re-implementation. We present the scientific workflow execution engine Hi-WAY, which implements a strict black-box view on tools to be integrated and data to be processed. Its generic yet powerful execution model allows Hi-WAY to execute workflows specified in a multitude of different languages. Hi-WAY compiles workflows into schedules for Hadoop YARN, harnessing its proven scalability. It allows for iterative and recursive workflow structures and optimizes performance through adaptive and data-aware scheduling. Reproducibility of workflow executions is achieved through automated setup of infrastructures and re-executable provenance traces. In this application paper we discuss limitations of current SWfMSs regarding scalable data analysis, describe the architecture of Hi-WAY, highlight its most important features, and report on several large-scale experiments from different scientific domains. © 2017, Copyright is with the authors.

  • 5. Dahlem, Dominik
    et al.
    Nickel, L.
    Sacha, Jan
    Biskupski, Bartosz
    Dowling, Jim
    RISE., Swedish ICT, SICS, Computer Systems Laboratory.
    Meier, Rene
    Towards Improving the Availability of Service Compositions2007Inngår i: Digital EcoSystems and Technologies Conference, 2007. DEST '07. Inaugural IEEE-IES, IEEE Press, 2007, 1, , s. 3Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The proliferation of open Internet-scale service-oriented platforms based on standards, such as WSDL, SOAP and BPEL, enables the composition of independent Web services into new value-added services. Such service compositions define the information flows between autonomous and potentially heterogeneous services across the boundaries of independent provider organisations. The availability of individual services in such digital ecosystems is likely to be variable due to fluctuating usage load and resource limitations imposed by a service provider's infrastructure. This problem becomes more acute as the number of services in a composition increases. This paper presents a mediation model for improving the availability of composed services. The mediation model masks failures in a service composition by transparently selecting (and executing) an alternative composition at runtime. Service consumers use a common interface to a set of functionally equivalent service compositions while a selection mechanism identifies the most suitable (alternative) service composition. An evaluation of our implementation of the proposed mediation model demonstrates that the consumer perceived availability of value-added services can be improved significantly

  • 6.
    Dowling, Jim
    RISE., Swedish ICT, SICS, Computer Systems Laboratory.
    Developing a distributed electronic health-record store for India2008Inngår i: ERCIM News, ISSN 0926-4981, E-ISSN 1564-0094, Vol. 75, s. 2s. 56-57Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The DIGHT project is addressing the problem of building a scalable and highly available information store for the Electronic Health Records (EHRs) of the over one billion citizens of India.

    Fulltekst (pdf)
    fulltext
  • 7.
    Dowling, Jim
    et al.
    RISE., Swedish ICT, SICS, Computer Systems Laboratory.
    Haridi, Seif
    RISE., Swedish ICT, SICS, Computer Systems Laboratory.
    Decentralized Reinforcement Learning for the Online Optimization of Distributed Systems2008Inngår i: Reinforcement Learning: Theory and Applications, Vienna, Austria: I-Tech Education and Publishing (Advanced Robotic Systems Journal) , 2008, , s. 25s. 143-166Kapittel i bok, del av antologi (Fagfellevurdert)
  • 8.
    Dowling, Jim
    et al.
    RISE - Research Institutes of Sweden (2017-2019), ICT, SICS. KTH Royal Institute of Technology, Sweden.
    Payberah, Amir
    RISE., Swedish ICT, SICS. KTH Royal Institute of Technology, Sweden.
    Shuffling with a Croupier: Nat-Aware Peer-Sampling2012Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Despite much recent research on peer-to-peer (P2P) protocols for the Internet, there have been relatively few practical protocols designed to explicitly account for Network Address Translation gateways (NATs). Those P2P protocols that do handle NATs circumvent them using relaying and hole-punching techniques to route packets to nodes residing behind NATs. In this paper, we present Croupier, a peer sampling service (PSS) that provides uniform random samples of nodes in the presence of NATs in the network. It is the first NAT-aware PSS that works without the use of relaying or hole-punching. By removing the need for relaying and hole-punching, we decrease the complexity and overhead of our protocol as well as increase its robustness to churn and failure. We evaluated Croupier in simulation, and, in comparison with existing NAT-aware PSS’, our results show similar randomness properties, but improved robustness in the presence of both high percentages of nodes behind NATs and massive node failures. Croupier also has substantially lower protocol overhead.

    Fulltekst (pdf)
    FULLTEXT01
  • 9.
    Dowling, Jim
    et al.
    RISE - Research Institutes of Sweden (2017-2019), ICT, SICS.
    Sacha, Jan
    Haridi, Seif
    RISE., Swedish ICT, SICS, Computer Systems Laboratory.
    Improving ICE Service Selection in a P2P System using the Gradient Topology2007Konferansepaper (Fagfellevurdert)
    Fulltekst (pdf)
    fulltext
  • 10.
    Hakimzadeh, Kamal
    et al.
    RISE., Swedish ICT, SICS. KTH Royal Institute of Technology, Sweden.
    Peiro Sajjad, Hooman
    KTH Royal Institute of Technology, Sweden.
    Dowling, Jim
    RISE - Research Institutes of Sweden (2017-2019), ICT, SICS. KTH Royal Institute of Technology, Sweden.
    Scaling HDFS with a Strongly Consistent Relational Model for Metadata2014Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The Hadoop Distributed File System (HDFS) scales to store tens of petabytes of data despite the fact that the entire file system's metadata must fit on the heap of a single Java virtual machine. The size of HDFS' metadata is limited to under 100 GB in production, as garbage collection events in bigger clusters result in heartbeats timing out to the metadata server(NameNode). In this paper, we address the problem of how to migrate the HDFS' metadata to a relational model, so that we can support larger amounts of storage on a shared nothing, in-memory, distributed database. Our main contribution is that we show how to provide at least as strong consistency semantics as HDFS while adding support for a multiple-writer, multiple-reader concurrency model. We guarantee freedom from deadlocks by logically organizing inodes (and their constituent blocks and replicas) into a hierarchy and having all metadata operations agree on a global order for acquiring both explicit locks and implicit locks on subtrees in the hierarchy. We use transactions with pessimistic concurrency control to ensure the safety and progress of metadata operations. Finally, we show how to improve performance of our solution by introducing a snapshotting mechanism at NameNodes that minimizes the number of roundtrips to the database

    Fulltekst (pdf)
    FULLTEXT01
  • 11.
    Ismail, Mahmoud
    et al.
    KTH Royal Institute of Technology, Sweden.
    Gebremeskel, Ermias
    RISE - Research Institutes of Sweden, ICT, SICS.
    Kakantousis, Theofilos
    RISE - Research Institutes of Sweden, ICT, SICS.
    Berthou, Gautier
    RISE - Research Institutes of Sweden, ICT, SICS.
    Dowling, Jim
    RISE - Research Institutes of Sweden, ICT, SICS.
    Hopsworks: Improving User Experience and Development on Hadoop with Scalable, Strongly Consistent Metadata2017Inngår i: Proceedings - International Conference on Distributed Computing Systems, 2017, s. 2525-2528Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Hadoop is a popular system for storing, managing,and processing large volumes of data, but it has bare-bonesinternal support for metadata, as metadata is a bottleneck andless means more scalability. The result is a scalable platform withrudimentary access control that is neither user-nor developer-friendly. Also, metadata services that are built on Hadoop, suchas SQL-on-Hadoop, access control, data provenance, and datagovernance are necessarily implemented as eventually consistentservices, resulting in increased development effort and morebrittle software. In this paper, we present a new project-based multi-tenancymodel for Hadoop, built on a new distribution of Hadoopthat provides a distributed database backend for the HadoopDistributed Filesystem's (HDFS) metadata layer. We extendHadoop's metadata model to introduce projects, datasets, andproject-users as new core concepts that enable a user-friendly, UI-driven Hadoop experience. As our metadata service is backed bya transactional database, developers can easily extend metadataby adding new tables and ensure the strong consistency ofextended metadata using both transactions and foreign keys.

  • 12.
    John, Wolfgang
    et al.
    Ericsson, Sweden.
    Balador, Ali
    Ericsson, Sweden.
    Taghia, Jalil
    Ericsson, Sweden.
    Johnsson, Andreas
    Ericsson, Sweden.
    Sjöberg, Johan
    Ericsson, Sweden.
    Marsh, Ian
    RISE Research Institutes of Sweden, Digitala system, Industriella system.
    Gustafsson, Jonas
    RISE Research Institutes of Sweden, Digitala system, Datavetenskap.
    Tonini, Federico
    Chalmers University of Technology, Sweden.
    Monti, Paolo
    Chalmers University of Technology, Sweden.
    Sköldström, Pontus
    Qamcom AB, Sweden.
    Dowling, Jim
    Hopsworks AB, Sweden.
    ANIARA Project - Automation of Network Edge Infrastructure and Applications with Artificial Intelligence2023Inngår i: ACM SIGAda Ada Letters, Vol. 42, nr 2, s. 92-95Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Emerging use-cases like smart manufacturing and smart cities pose challenges in terms of latency, which cannot be satisfied by traditional centralized infrastructure. Edge networks, which bring computational capacity closer to the users/clients, are a promising solution for supporting these critical low latency services. Different from traditional centralized networks, the edge is distributed by nature and is usually equipped with limited compute capacity. This creates a complex network to handle, subject to failures of different natures, that requires novel solutions to work in practice. To reduce complexity, edge application technology enablers, advanced infrastructure and application orchestration techniques need to be in place where AI and ML are key players.

  • 13.
    Niazi, Salman
    et al.
    KTH Royal Institute of Technology, Sweden.
    Ismail, Mahmoud
    KTH Royal Institute of Technology, Sweden.
    Berthou, Gautier
    RISE., Swedish ICT, SICS.
    Dowling, Jim
    RISE - Research Institutes of Sweden (2017-2019), ICT, SICS. KTH Royal Institute of Technology, Sweden.
    Leader Election Using NewSQL Database Systems2015Inngår i: Distributed Applications and Interoperable Systems, Springer , 2015, 16, Vol. 9038, s. 158-172Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Leader election protocols are a fundamental building block for replicated distributed services. They ease the design of leader-based coordination protocols that tolerate failures. In partially synchronous systems, designing a leader election algorithm, that does not permit multiple leaders while the system is unstable, is a complex task. As a result many production systems use third-party distributed coordination services, such as ZooKeeper and Chubby, to provide a reliable leader election service. However, adding a third-party service such as ZooKeeper to a distributed system incurs additional operational costs and complexity. ZooKeeper instances must be kept running on at least three machines to ensure its high availability. In this paper, we present a novel leader election protocol using NewSQL databases for partially synchronous systems, that ensures at most one leader at any given time. The leader election protocol uses the database as distributed shared memory. Our work enables distributed systems that already use NewSQL databases to save the operational overhead of managing an additional third-party service for leader election. Our main contribution is the design, implementation and validation of a practical leader election algorithm, based on NewSQL databases, that has performance comparable to a leader election implementation using a state-of-the-art distributed coordination service, ZooKeeper.

  • 14.
    Payberah, Amir
    et al.
    RISE., Swedish ICT, SICS.
    Dowling, Jim
    RISE - Research Institutes of Sweden (2017-2019), ICT, SICS.
    Haridi, Seif
    RISE., Swedish ICT, SICS, Computer Systems Laboratory.
    GLive: The Gradient overlay as a market maker for mesh-based P2P live streaming2011Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Peer-to-Peer (P2P) live video streaming over the Internet is becoming increasingly popular, but it is still plagued by problems of high playback latency and intermittent playback streams. This paper presents GLive, a distributed market-based solution that builds a mesh overlay for P2P live streaming. The mesh overlay is constructed such that (i) nodes with increasing upload bandwidth are located closer to the media source, and (ii) nodes with similar upload bandwidth become neighbours. We introduce a market-based approach that matches nodes willing and able to share the stream with one another. However, market-based approaches converge slowly on random overlay networks, and we improve the rate of convergence by adapting our market-based algorithm to exploit the clustering of nodes with similar upload bandwidths in our mesh overlay. We address the problem of free-riding through nodes preferentially uploading more of the stream to the best uploaders. We compare GLive with our previous tree-based streaming protocol, Sepidar, and NewCoolstreaming in simulation, and our results show significantly improved playback continuity and playback latency.

    Fulltekst (pdf)
    fulltext
  • 15.
    Payberah, Amir
    et al.
    RISE., Swedish ICT, SICS.
    Dowling, Jim
    RISE - Research Institutes of Sweden (2017-2019), ICT, SICS.
    Haridi, Seif
    RISE., Swedish ICT, SICS, Computer Systems Laboratory.
    Gozar: NAT-friendly Peer Sampling with One-Hop Distributed NAT Traversal2011Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Gossip-based peer sampling protocols have been widely used as a building block for many large-scale distributed applications. However, Network Address Translation gateways (NATs) cause most existing gossiping protocols to break down, as nodes cannot establish direct connections to nodes behind NATs (private nodes). In addition, most of the existing NAT traversal algorithms for establishing connectivity to private nodes rely on third party servers running at a well-known, public IP addresses. In this paper, we present Gozar, a gossip-based peer sampling service that: (i) provides uniform random samples in the presence of NATs, and (ii) enables direct connectivity to sampled nodes using a fully distributed NAT traversal service, where connection messages require only a single hop to connect to private nodes. We show in simulation that Gozar preserves the randomness properties of a gossip-based peer sampling service. We show the robustness of Gozar when a large fraction of nodes reside behind NATs and also in catastrophic failure scenarios. For example, if 80% of nodes are behind NATs, and 80% of the nodes fail, more than 92% of the remaining nodes stay connected. In addition, we compare Gozar with existing NAT-friendly gossip-based peer sampling services, Nylon and ARRG. We show that Gozar is the only system that supports one-hop NAT traversal, and its overhead is roughly half of Nylon’s.

    Fulltekst (pdf)
    fulltext
  • 16.
    Payberah, Amir
    et al.
    RISE., Swedish ICT, SICS.
    Dowling, Jim
    RISE - Research Institutes of Sweden (2017-2019), ICT, SICS.
    Rahimian, Fatemeh
    RISE., Swedish ICT, SICS, Computer Systems Laboratory.
    Haridi, Seif
    RISE., Swedish ICT, SICS, Computer Systems Laboratory.
    gradienTv: market-based P2P live media streaming on the Gradient overlay2010Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper presents gradienTv, a distributed, market-based approach to live streaming. In gradienTv, multiple streaming trees are constructed using a market-based approach, such that nodes with increasing upload bandwidth are located closer to the media source at the roots of the trees. Market-based approaches, however, exhibit slow convergence properties on random overlay networks, so to facilitate the timely discovery of neighbours with similar upload bandwidth capacities (thus, enabling faster convergence of streaming trees), we use the gossip-generated Gradient overlay network. In the Gradient overlay, nodes are ordered by a gradient of node upload capacities and the media source is the highest point in the gradient. We compare gradienTv with state-of-the-art NewCoolstreaming in simulation, and the results show significantly improved bandwidth utilization, playback latency, playback continuity, and reduction in the average number of hops from the media source to nodes.

  • 17.
    Payberah, Amir
    et al.
    RISE., Swedish ICT, SICS.
    Dowling, Jim
    RISE - Research Institutes of Sweden (2017-2019), ICT, SICS.
    Rahimian, Fatemeh
    RISE., Swedish ICT, SICS. Computer Systems Laboratory.
    Haridi, Seif
    RISE., Swedish ICT, SICS, Computer Systems Laboratory.
    Sepidar: Incentivized Market-Based P2P Live-Streaming on the Gradient Overlay Network2010Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Live streaming of video content using overlay networks has gained widespread adoption on the Internet. This paper presents Sepidar, a distributed market-based model, that builds and maintains overlay network trees, which are approximately minimal height, for delivering live media as a number of substreams. A streaming tree is constructed for each substream such that nodes that contribute higher amounts of upload bandwidth are located increasingly closer to the media source at the root of the tree. While our distributed market model can be run against a random sample of nodes, we improve its convergence time to stabilize a tree by executing against a sample of nodes that contribute similar amounts of upload bandwidth. We use the Gradient overlay network to generate samples of such nodes. We address the problem of free-riding through parent nodes auditing the behaviour of their child nodes. We evaluate Sepidar by comparing it in simulation with state-of-the-art NewCoolstreaming. Our results show significantly improved playback latency and playback continuity under churn, flash crowd, and catastrophic failure experiment scenarios. We also show that using the Gradient improves convergence time of our distributed market model compared to a random overlay network. Finally, we show that Sepidar punishes the performance of free-riders, and that nodes are incentivized to contribute more upload bandwidth by relatively improved performance.

    Fulltekst (pdf)
    fulltext
  • 18.
    Payberah, Amir H.
    et al.
    RISE., Swedish ICT, SICS.
    Dowling, Jim
    RISE., Swedish ICT, SICS.
    Rahimain, Fatemeh
    RISE., Swedish ICT, SICS.
    Haridi, Seif
    RISE., Swedish ICT, SICS.
    Distributed optimization of P2P live streaming overlays2012Inngår i: Computing, ISSN 0010-485X, E-ISSN 1436-5057, Vol. 94, nr 8-10, s. 621-647Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Peer-to-peer live media streaming over the Internet is becoming increasingly more popular, though it is still a challenging problem. Nodes should receive the stream with respect to intrinsic timing constraints, while the overlay should adapt to the changes in the network and the nodes should be incentivized to contribute their resources. In this work, we meet these contradictory requirements simultaneously, by introducing a distributed market model to build an efficient overlay for live media streaming. Using our market model, we construct two different overlay topologies, tree-based and mesh-based, which are the two dominant approaches to the media distribution. First, we build an approximately minimal height multiple-tree data dissemination overlay, called Sepidar. Next, we extend our model, in GLive, to make it more robust in dynamic networks by replacing the tree structure with a mesh. We show in simulation that the mesh-based overlay outperforms the multiple-tree overlay. We compare the performance of our two systems with the state-of-the-art NewCoolstrea-ming, and observe that they provide better playback continuity and lower playback latency than that of NewCoolstreaming under a variety of experimental scenarios. Although our distributed market model can be run against a random sample of nodes, we improve its convergence time by executing it against a sample of nodes taken from the Gradient overlay. The evaluations show that the streaming overlays converge faster when our market model works on top of the Gradient overlay.

  • 19.
    Payberah, Amir H.
    et al.
    RISE., Swedish ICT, SICS.
    Kavalionak, Hanna
    University of Trento, Italy.
    Montresor, Alberto
    University of Trento, Italy.
    Dowling, Jim
    RISE., Swedish ICT, SICS.
    Haridi, Seif
    RISE., Swedish ICT, SICS.
    Lightweight gossip-based distribution estimation2013Inngår i: IEEE International Conference on Communications, Institute of Electrical and Electronics Engineers Inc. , 2013, s. 3439-3443, artikkel-id 6655081Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Monitoring the global state of an overlay network is vital for the self-management of peer-to-peer (P2P) systems. Gossip-based algorithms are a well-known technique that can provide nodes locally with aggregated knowledge about the state of the overlay network. In this paper, we present a gossip-based protocol to estimate the global distribution of attribute values stored across a set of nodes in the system. Our algorithm estimates the distribution both efficiently and accurately. The key contribution of our algorithm is that it has substantially lower overhead than existing distribution estimation algorithms. We evaluated our system in simulation, and compared it against the state-of-the-art solutions. The results show similar accuracy to its counterparts, but with a communication overhead of an order of magnitude lower than them.

  • 20. Sacha, Jan
    et al.
    Biskupski, Bartosz
    Dahlem, Dominik
    Cunningham, Raymond
    Dowling, Jim
    RISE., Swedish ICT, SICS, Computer Systems Laboratory.
    Meier, Rene
    A Service-Oriented Peer-to-Peer Architecture for a Digital Ecosystem2007Inngår i: Digital EcoSystems and Technologies Conference, 2007. DEST '07. Inaugural IEEE-IES, 2007, 1Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Service-oriented computing is becoming an increasingly popular paradigm for modelling and building distributed systems in heterogeneous, decentralised, and open environments. However, proposed service-oriented architectures are usually based on centralised components, such as service registries or service brokers, that introduce reliability, management, and performance issues. In this paper, we present a fully decentralised service-oriented architecture built on top of a self-organising peer-to-peer infrastructure. This architecture is especially designed to support digital ecosystems due to its low deployment and maintenance cost and inherently decentralised nature

  • 21. Terelius, Hakan
    et al.
    Shi, Guodong
    Dowling, Jim
    RISE - Research Institutes of Sweden (2017-2019), ICT, SICS.
    Payberah, Amir
    RISE., Swedish ICT, SICS.
    Gattami, Ather
    Johansson, Karl Henrik
    Converging an Overlay Network to a Gradient Topology2011Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In this paper, we investigate the topology convergence problem for the gossip-based Gradient overlay network. In an overlay network where each node has a local utility value, a Gradient overlay network is characterized by the properties that each node has a set of neighbors containing higher utility values, such that paths of increasing utilities emerge in the network topology. The Gradient overlay network is built using gossiping and a preference function that samples from nodes using a uniform random peer sampling service. We analyze it using tools from matrix analysis, and we prove both the necessary and sufficient conditions for convergence to a complete gradient structure, as well as estimating the convergence time. Finally, we show in simulations the potential of the Gradient overlay, by building a more efficient live streaming peer-to-peer (P2P) system than one built using uniform random peer sampling.

    Fulltekst (pdf)
    fulltext
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