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Ilkka Norros

  1. Stable, scalable, decentralized P2P file sharing with non-altruistic peers.

    Tue, 07/19/2011 - 15:01 — SomNambul
    Authors: Ilkka Norros, Barlas Oğuz, Venkat Anantharam
    Subjects: Networking and Internet Architecture
    Abstract

    P2P systems provide a scalable solution for distributing large files in a
    network. The file is split into many chunks, and peers contact other peers to
    collect missing chunks to eventually complete the entire file. The so-called
    `rare chunk' phenomenon, where a single chunk becomes rare and prevents peers
    from completing the file, is a threat to the stability of such systems.
    Practical systems such as BitTorrent overcome this issue by requiring a global
    search for the rare chunk, which necessitates a centralized mechanism.

  2. On the stability of two-chunk file-sharing systems.

    Fri, 10/30/2009 - 16:01 — SomNambul
    Authors: Ilkka Norros, Hannu Reittu, Timo Eirola
    Subjects: Operating Systems
    Abstract

    We consider five different peer-to-peer file sharing systems with two chunks,
    with the aim of finding chunk selection algorithms that have provably stable
    performance with any input rate and assuming non-altruistic peers who leave the
    system immediately after downloading the second chunk. We show that many
    algorithms that first looked promising lead to unstable or oscillating
    behavior. However, we end up with a system with desirable properties.

  3. On convergence to stationarity of fractional Brownian storage.

    Tue, 09/01/2009 - 12:47 — SomNambul
    Authors: Michel Mandjes, Ilkka Norros, Peter Glynn
    Subjects: Probability
    Abstract

    With $M(t):=\sup_{s\in[0,t]}A(s)-s$ denoting the running maximum of a
    fractional Brownian motion $A(\cdot)$ with negative drift, this paper studies
    the rate of convergence of $\mathbb {P}(M(t)>x)$ to $\mathbb{P}(M>x)$. We
    define two metrics that measure the distance between the (complementary)
    distribution functions $\mathbb{P}(M(t)>\cdot)$ and $\mathbb{P}(M>\cdot)$.

  4. On convergence to stationarity of fractional Brownian storage.

    Tue, 09/01/2009 - 12:47 — SomNambul
    Authors: Michel Mandjes, Ilkka Norros, Peter Glynn
    Subjects: Probability
    Abstract

    With $M(t):=\sup_{s\in[0,t]}A(s)-s$ denoting the running maximum of a
    fractional Brownian motion $A(\cdot)$ with negative drift, this paper studies
    the rate of convergence of $\mathbb {P}(M(t)>x)$ to $\mathbb{P}(M>x)$. We
    define two metrics that measure the distance between the (complementary)
    distribution functions $\mathbb{P}(M(t)>\cdot)$ and $\mathbb{P}(M>\cdot)$.

Math-arch

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