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A class of synchronization protocols for dense, large-scale sensor networks is presented. The protocols build on the recent work of Hong, Cheow, and Scaglione [5, 6] in which the synchronization update rules are modeled by a system of pulse-coupled oscillators. In the present work, we define a class of models that converge to a synchronized state based on(More)
A landslide occurs when the balance between a hill's weight and the countering resistance forces is tipped in favor of gravity. While the physics governing the interplay between these competing forces is fairly well understood, prediction of landslides has been hindered thus far by the lack of field measurements over large temporal and spatial scales(More)
In this paper we present a constrained optimization approach to aggregate results from multiple slot fillers taking into account the confidence values generated by individual slot fillers. The results obtained from aggregation were used to validate the individual runs. We demonstrated that the proposed aggregation approach led to a significant performance(More)
Over the past few years, a number of distributed algorithms have been developed for integrating the measurements acquired by a wireless sensor network. Among them, average consensus algorithms have drawn significant attention due to a number of practical advantages, such as robustness to noise in the measurements, robustness to changes in the network(More)
Simultaneous perturbation stochastic approximation (SPSA) algorithms have been found to be very effective for high-dimensional simulation optimization problems. The main idea is to estimate the gradient using simulation output performance measures at only <i>two</i> settings of the <i>N</i>-dimensional parameter vector being optimized rather than at the(More)
Dual site spectrum measurements have been made in the public safety band in Howard County, Maryland, USA. The public safety band is of interest because of its obvious importance and the increasing need to determine whether improved spectral utilization would accommodate increased usage for public safety. Two receiver suites were synchronized and used to(More)
In this paper we discuss an economic model for resource sharing in large-scale distributed systems. The model captures traditional concepts such as consumer satisfaction and provider revenues and enables us to analyze the effect of different pricing strategies upon measures of performance important for the consumers and the providers. We show that given a(More)
We present a stochastic approximation algorithm based on penalty function method and a simultaneous perturbation gradient estimate for solving stochastic optimization problems with general inequality constraints. We present a general convergence result that applies to a class of penalty functions including the quadratic penalty function, the augmented(More)
We present a stochastic approximation algorithm based on penalty function method and a simultaneous perturbation gradient estimate for solving stochastic optimisation problems with general inequality constraints. We present a general convergence result that applies to a class of penalty functions including the quadratic penalty function, the augmented(More)