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Today's Internet is a massive, distributed network which continues to explode in size as e-commerce and related activities grow. The heterogeneous and largely unregulated structure of the Internet renders tasks such as dynamic routing, optimized service provision, service level verification, and detection of anomalous/malicious behavior extremely(More)
In this paper we consider a sequential, coarse-to-fine estimation of a piecewise constant function with smooth boundaries. Accurate detection and localization of the boundary (a manifold) is the key aspect of this problem. In general, algorithms capable of achieving optimal performance require exhaustive searches over large dictionaries that grow(More)
Compressive Sampling (CS), also called Compressed Sensing , entails making observations of an unknown signal by projecting it onto random vectors. Recent theoretical results show that if the signal is sparse (or nearly sparse) in some basis , then with high probability such observations essentially encode the salient information in the signal. Further, the(More)
The theory of compressed sensing shows that sparse signals in high-dimensional spaces can be recovered from a relatively small number of samples in the form of random projections. However, in severely resource-constrained settings even CS techniques may fail, and thus, a less aggressive goal of partial signal recovery is reasonable. This paper describes a(More)
—A multi-step adaptive resampling procedure is proposed , and shown to be an effective approach when detecting high-dimensional sparse signals in noise. Each step of the proposed procedure refines an estimate of the true signal subspace, allowing sensing energy to be focused more directly into the subspace of interest and significantly improving the(More)
We document and discuss a dramatic change in the cyclical behavior of aggregate skilled hours since the mid-1980's. Using CPS data for 1979:1-2003:4, we find that the volatility of skilled hours relative to the volatility of GDP has nearly tripled since 1984. In contrast, the cyclical properties of unskilled hours have remained essentially unchanged. We(More)
  • H Bouakez, E Cardia, F J Ruge-Murcia, Rui Castro, Juan Dolado, Gregor Smith +1 other
  • 2007
This paper constructs and estimates a sticky-price, Dynamic Stochastic General Equilibrium model with heterogenous production sectors. Firms in dierent sectors vary in their price rigidity, production technology, and the combination of material and investment inputs. In particular, rms buy inputs from all sectors using the actual Input-Output Matrix and(More)