Chinmoy Dutta

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We study how to spread k tokens of information to every node on an n-node dynamic network, the edges of which are changing at each round. This basic gossip problem can be completed in O(n+k) rounds in any static network, and determining its complexity in dynamic networks is central to understanding the algorithmic limits and capabilities of various dynamic(More)
We study a distributed randomized information propagation mechanism in networks we call the <i>coalescing-branching</i> random walk (cobra walk, for short). A cobra walk is a generalization of the well-studied &#8220;standard&#8221; random walk, and is useful in modeling and understanding the Susceptible-Infected- Susceptible (SIS)-type of epidemic(More)
We study the problem of constructing universal Steiner trees for undirected graphs. Given a graph G and a root node r, we seek a single spanning tree T of minimum stretch, where the stretch of T is defined to be the maximum ratio, over all terminal sets X, of the cost of the minimal sub-tree T<sub>X</sub> of T that connects X to r to the cost of an optimal(More)
We show a tight lower bound of &#937;(<i>N</i> log log <i>N</i>) on the number of transmission required to compute the parity of <i>N</i> bits (with constant error) in a network of <i>N</i> randomly placed sensors, communicating using local transmissions, and operating with power near the connectivity threshold. This result settles a question left open by(More)
We study the fundamental problem of information spreading (also known as gossip) in dynamic networks. In gossip, or more generally, k-gossip, there are k pieces of information (or tokens) that are initially present in some nodes and the problem is to disseminate the k tokens to all nodes. The goal is to accomplish the task in as few rounds of distributed(More)
We show tight necessary and sufficient conditions on the sizes of small bipartite graphs whose union is a larger bipartite graph that has no large bipartite independent set. Our main result is a common generalization of two classical results in graph theory: the theorem of Kővári, Sós and Turán on the minimum number of edges in a bipartite graph that has no(More)
We show a tight lower bound of Omega(N\log\log N) on the number of transmissions required to compute several functions (including the parity function and the majority function) in a network of N randomly placed sensors, communicating using local transmissions, and operating with power near the connectivity threshold. This result considerably simplifies and(More)
We show a tight lower bound of Ω(N log logN) on the number of transmissions required to compute the parity of N input bits with constant error in a noisy communication network of N randomly placed sensors, each having one input bit and communicating with others using local transmissions with power near the connectivity threshold. This result settles the(More)