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Bikash Kumar Dey

  1. Upper Bounds on the Capacity of Binary Channels with Causal Adversaries.

    Fri, 04/13/2012 - 15:01 — SomNambul
    Authors: Bikash Kumar Dey, Sidharth Jaggi, Michael Langberg, Anand D. Sarwate
    Subjects: Information Theory
    Abstract

    In this work we consider the communication of information in the presence of
    a causal adversarial jammer. In the setting under study, a sender wishes to
    communicate a message to a receiver by transmitting a codeword
    $\mathbf{x}=(x_1,...,x_n)$ bit-by-bit over a communication channel. The sender
    and receiver do not share common randomness. The adversarial jammer can view
    the transmitted bits $x_i$ one at a time, and can change up to a $p$-fraction
    of them.

  2. Network Flows for Functions.

    Fri, 10/01/2010 - 15:01 — SomNambul
    Authors: Bikash Kumar Dey, Virag Shah, D. Manjunath
    Subjects: Networking and Internet Architecture
    Abstract

    We consider in-network computation of an arbitrary function over an arbitrary
    communication network. A network with capacity constraints on the links is
    given. Some nodes in the network generate data, e.g., like sensor nodes in a
    sensor network. An arbitrary function of this distributed data is to be
    obtained at a terminal node. The structure of the function is described by a
    given computation schema, which in turn is represented by a directed tree. We
    design computing and communicating schemes to obtain the function at the
    terminal at the maximum rate.

  3. A Necessary and Sufficient Condition for Solvability of a 3s/3t Sum-network.

    Tue, 01/26/2010 - 16:01 — SomNambul
    Authors: Bikash Kumar Dey, Sagar Shenvi
    Subjects: Information Theory
    Abstract

    We consider a directed acyclic network with three sources and three terminals
    such that each source independently generates one symbol from a given field $F$
    and each terminal wants to receive the sum (over $F$) of the source symbols.
    Each edge in the network is considered to be error-free and delay-free and can
    carry one symbol from the field. We call such a network a 3-source 3-terminal
    {\it $(3s/3t)$ sum-network}. In this paper, we give a necessary and sufficient
    condition for a $3s/3t$ sum-network to allow all terminals to receive the sum
    of the source symbols over \textit{any} field.

  4. Estimating Network Link Characteristics using Packet-Pair Dispersion: A Discrete Time Queueing Theoretic View.

    Thu, 11/19/2009 - 16:01 — SomNambul
    Authors: Bikash Kumar Dey, D. Manjunath, Supriyo Chakraborty
    Subjects: Networking and Internet Architecture
    Abstract

    Packet-dispersion based measurement tools insert pairs of probe packets with
    a known separation into the network for transmission over a unicast path or a
    multicast tree. Samples of the separation between the probe pairs at the
    destination(s) are observed. Heuristic techniques are then used by these tools
    to estimate the path characteristics from the observations.

  5. A simple necessary and sufficient condition for the double unicast problem.

    Thu, 10/01/2009 - 00:35 — SomNambul
    Authors: Bikash Kumar Dey, Sagar Shenvi
    Subjects: Information Theory
    Abstract

    We consider a directed acyclic network where there are two source-terminal
    pairs and the terminals need to receive the symbols generated at the respective
    sources. Each source independently generates one symbol from a given alphabet
    in an i.i.d. manner per unit time. Each edge in the network is error-free,
    delay-free, and can carry one symbol from the alphabet in unit time. We give a
    simple necessary and sufficient condition for being able to simultaneously
    satisfy the unicast requirements of the two source-terminal pairs using network
    coding.

  6. A Channel Coding Perspective of Collaborative Filtering.

    Wed, 08/19/2009 - 19:30 — SomNambul
    Authors: Bikash Kumar Dey, S. T. Aditya, Onkar Dabeer
    Subjects: Information Theory
    Abstract

    We consider the problem of collaborative filtering from a channel coding
    perspective. We model the underlying rating matrix as a finite alphabet matrix
    with block constant structure. The observations are obtained from this
    underlying matrix through a discrete memoryless channel with a noisy part
    representing noisy user behavior and an erasure part representing missing data.
    Moreover, the clusters over which the underlying matrix is constant are {\it
    unknown}.

  7. Sum-networks: system of polynomial equations, reversibility, insufficiency of linear network coding, unachievability of coding capacity.

    Tue, 08/18/2009 - 11:53 — SomNambul
    Authors: Brijesh Kumar Rai, Bikash Kumar Dey
    Subjects: Information Theory
    Abstract

    A directed acyclic network is considered where all the terminals demand the
    sum of the symbols generated at all the sources. We call such a network as a
    sum-network. It is shown that there exists a solvably (and linear solvably)
    equivalent sum-network for any multiple-unicast network (and more generally,
    for any acyclic directed network where each terminal node demands a subset of
    the symbols generated at all the sources). It is also shown that there exists a
    linear solvably equivalent multiple-unicast network for every sum-network.

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