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We study a general class of bicriteria network design problems. A generic problem in this class is as follows: Given an undirected graph and two minimization objectives (under different cost functions), with a budget specified on the first, find a ¡subgraph from a given subgraph-class that minimizes the second objective subject to the budget on the first.(More)
We study the problem of finding small trees. Classical network design problems are considered with the additional constraint that only a specified number k of nodes are required to be connected in the solution. A prototypical example is the kMST problem in which we require a tree of minimum weight spanning at least k nodes in an edge-weighted graph. We show(More)
A graph G is said to be d-distinguishable if there is a d-coloring of G which no non-trivial automorphism preserves. It was conjectured that if jGj > jAut(G)j and the Aut(G) action on G has no singleton orbits, then G is 2-distinguishable. We give an example where this fails. We partially repair the conjecture by showing that when " enough motion occurs, "(More)
Many emerging scientific and industrial applications require transferring multiple Tbytes of data on a daily basis. Examples include pushing scientific data from particle accelerators/colliders to laboratories around the world, synchronizing data-centers across continents, and replicating collections of high definition videos from events taking place at(More)
Over the past two decades, the web has provided dramatic improvements in the ease of sharing content. Unfortunately, the costs of distributing this content are largely incurred by web site operators; popular web sites are required to make substantial monetary investments in serving infrastructure or cloud computing resources---or must pay other(More)
Recently, cloud computing services such as Amazon EC2 have used virtualization to provide customers with virtual machines running on the provider's hardware, typically charging by wall clock time rather than resources consumed. Under this business model, manipulation of the scheduler may allow theft-of-service at the expense of other customers. We have(More)
We introduce a notion of <i>universality</i> in the context of optimization problems with partial information. Universality is a framework for dealing with uncertainty by guaranteeing a certain quality of goodness for all possible completions of the partial information set. Universal variants of optimization problems can be defined that are both natural and(More)
We i n troduce the natural class S P 2 containing those languages which m a y be expressed in terms of two symmetric quantiiers. This class lies between P 2 and P 2 P 2 and naturally generates a symmetric" hierarchy corresponding to the polynomial-time hierarchy. W e demonstrate, using the probabilistic method, new containment theorems for BPP. W e show(More)
In this paper, we propose to address the energy efficient routing problem in multi-hop wireless networks with accumulative relay. In the accumulative relay model, partially overheard signals of previous transmissions for the same packet are used to decode it using a maximal ratio combiner technique [J.G. Proakis, 2001]. Therefore, additional energy saving(More)