Comparing Methods for Interpolation to Improve Raster Digital Elevation Models

Digital elevation models (DEMs) are available as raster files at 100m, 30m, and 10m resolutions for the contiguous United States and are used in a variety of geographic analyses. Some projects may require a finer resolution. GIS software offers many options for interpolating data to higher resolutions. We compared ten interpolation methods using 10m sample data from the Ouachita Mountains in central Arkansas. We interpolated the 10m DEM to 5m, 2.5m, and 1m resolutions and compared the absolute mean difference (AMD) for each using surveyed control points. Overall, there was little difference in the accuracy between interpolation methods at the resolutions tested and minimal departure from the original 10m raster

Design for waste-management system

Study was made and system defined for water-recovery and solid-waste processing for low-rise apartment complexes. System can be modified to conform with unique requirements of community, including hydrology, geology, and climate. Reclamation is accomplished by treatment process that features reverse-osmosis membranes

Study of water recovery and solid waste processing for aerospace and domestic applications. Volume 2: Final report

The manner in which current and advanced technology can be applied to develop practical solutions to existing and emerging water supply and waste disposal problems is evaluated. An overview of water resource factors as they affect new community planning, and requirements imposed on residential waste treatment systems are presented. The results of equipment surveys contain information describing: commercially available devices and appliances designed to conserve water; devices and techniques for monitoring water quality and controlling back contamination; and advanced water and waste processing equipment. System concepts are developed and compared on the basis of current and projected costs. Economic evaluations are based on community populations of from 2,000 to 250,000. The most promising system concept is defined in sufficient depth to initiate detailed design

Analytical Results for Multifractal Properties of Spectra of Quasiperiodic Hamiltonians near the Periodic Chain

The multifractal properties of the electronic spectrum of a general quasiperiodic chain are studied in first order in the quasiperiodic potential strength. Analytical expressions for the generalized dimensions are found and are in good agreement with numerical simulations. These first order results do not depend on the irrational incommensurability.Comment: 10 Pages in RevTeX, 2 Postscript figure

Spectrum and diffusion for a class of tight-binding models on hypercubes

We propose a class of exactly solvable anisotropic tight-binding models on an infinite-dimensional hypercube. The energy spectrum is analytically computed and is shown to be fractal and/or absolutely continuous according to the value hopping parameters. In both cases, the spectral and diffusion exponents are derived. The main result is that, even if the spectrum is absolutely continuous, the diffusion exponent for the wave packet may be anything between 0 and 1 depending upon the class of models.Comment: 5 pages Late

What determines the spreading of a wave packet?

The multifractal dimensions D2^mu and D2^psi of the energy spectrum and eigenfunctions, resp., are shown to determine the asymptotic scaling of the width of a spreading wave packet. For systems where the shape of the wave packet is preserved the k-th moment increases as t^(k*beta) with beta=D2^mu/D2^psi, while in general t^(k*beta) is an optimal lower bound. Furthermore, we show that in d dimensions asymptotically in time the center of any wave packet decreases spatially as a power law with exponent D_2^psi - d and present numerical support for these results.Comment: Physical Review Letters to appear, 4 pages postscript with figure

Stable Quantum Resonances in Atom Optics

A theory for stabilization of quantum resonances by a mechanism similar to one leading to classical resonances in nonlinear systems is presented. It explains recent surprising experimental results, obtained for cold Cesium atoms when driven in the presence of gravity, and leads to further predictions. The theory makes use of invariance properties of the system, that are similar to those of solids, allowing for separation into independent kicked rotor problems. The analysis relies on a fictitious classical limit where the small parameter is {\em not} Planck's constant, but rather the detuning from the frequency that is resonant in absence of gravity.Comment: 5 pages, 3 figure

High plasma levels of endothelin-1 enhance the predictive value of preclinical atherosclerosis for future cerebrovascular and cardiovascular events: a 20-year prospective study

BACKGROUND AND PURPOSE: Clinical and experimental evidence suggests that endothelin-1 (Et-1) plays a role in cardiac and vascular disease. In the present study, we investigated the prognostic significance of Et-1 for cerebrovascular and cardiovascular outcome, in a 20-year follow-up. METHODS: We studied 82 originally healthy individuals, referred to our Unit of Cardiovascular Prevention, to evaluate the presence of asymptomatic carotid lesions. We subdivided these individuals into two groups, according to the plasma values of Et-1 (respectively ≤ or >2.7 pg/ml). Traditional cardiovascular risk factors were investigated, and by carotid ultrasound examination, we distinguished between normal individuals and those with intima-media thickening or asymptomatic carotid plaque. RESULTS: Major cardiac and cerebral events (all-cause death, myocardial infarction, revascularization procedures, fatal and nonfatal stroke) were registered in 41 individuals and significantly more in those with high vs. low Et-1 levels (95 vs. 5%; P < 0.0001). Furthermore, by logistic multivariate regression analysis, we found that among all evaluated baseline clinical and laboratory variables, hypertension [odds ratio (OR): 20.4 (3.3-127), P = 0.001], high Et-1 concentrations [OR: 1.4 (1.0-1.8), P = 0.02] and the presence of intima-media thickness or asymptomatic carotid plaque [OR: 3.7 (1.14-12.1), P = 0.02] were independent predictors of future events. Finally, integrating technical and laboratory data, high levels of Et-1 have defined a high risk of major cardiac and cerebral event and stroke at follow-up, which increased in relation to the progression of carotid atherosclerosis (P < 0.05). CONCLUSION: Et-1 plasmatic levels significantly influence the cardiovascular and cerebrovascular risk profile, beyond traditional cardiovascular risk factors and preclinical carotid atherosclerosis