693 research outputs found
Automating the Naval Officer Selection and Promotion System
The selection and promotion system for officers in the U.S. Navy has followed an oscillating course for the past two generations. Though this system has been oriented toward a single goal, the promotion of the best fitted or most qualified officers, its environment and its inherent weaknesses have caused it to vacillate sufficiently to cast some doubt on the system\u27s ability to achieve this goal in all cases
Equatorial rain forest lateritic mantles : a geomembrane filter
ABSTRACT The superimposed weathering layers in equatorial rain forest lateritic mantles from Gabon, AtXca, function as interactive compartments forming a dynamic semipermeable geomembrane filter. Selectivity of the filter is controlled by a progressive downward disappearance Of Connected macropore pathways created by bioturbation and dissolution. The natural balance of root activity, translocation, dissolution, deformation, and pore evolution leads to the development of porous and permeable, mature, open geochemical weathering systems at the expense of the lithosphere. These conclusions can be useful in modeling the fate of lateritic soils, which cover one-third of the emerged area of the world and which are economically important both as metal deposits and agricultural soils
VERITAS: the Very Energetic Radiation Imaging Telescope Array System
The Very Energetic Radiation Imaging Telescope Array System (VERITAS)
represents an important step forward in the study of extreme astrophysical
processes in the universe. It combines the power of the atmospheric Cherenkov
imaging technique using a large optical reflector with the power of
stereoscopic observatories using arrays of separated telescopes looking at the
same shower. The seven identical telescopes in VERITAS, each of aperture 10 m,
will be deployed in a filled hexagonal pattern of side 80 m; each telescope
will have a camera consisting of 499 pixels with a field of view of 3.5 deg
VERITAS will substantially increase the catalog of very high energy (E >
100GeV) gamma-ray sources and greatly improve measurements of established
sources.Comment: 44 pages, 16 figure
The First VERITAS Telescope
The first atmospheric Cherenkov telescope of VERITAS (the Very Energetic
Radiation Imaging Telescope Array System) has been in operation since February
2005. We present here a technical description of the instrument and a summary
of its performance. The calibration methods are described, along with the
results of Monte Carlo simulations of the telescope and comparisons between
real and simulated data. The analysis of TeV -ray observations of the
Crab Nebula, including the reconstructed energy spectrum, is shown to give
results consistent with earlier measurements. The telescope is operating as
expected and has met or exceeded all design specifications.Comment: Accepted by Astroparticle Physic
Low Complexity Regularization of Linear Inverse Problems
Inverse problems and regularization theory is a central theme in contemporary
signal processing, where the goal is to reconstruct an unknown signal from
partial indirect, and possibly noisy, measurements of it. A now standard method
for recovering the unknown signal is to solve a convex optimization problem
that enforces some prior knowledge about its structure. This has proved
efficient in many problems routinely encountered in imaging sciences,
statistics and machine learning. This chapter delivers a review of recent
advances in the field where the regularization prior promotes solutions
conforming to some notion of simplicity/low-complexity. These priors encompass
as popular examples sparsity and group sparsity (to capture the compressibility
of natural signals and images), total variation and analysis sparsity (to
promote piecewise regularity), and low-rank (as natural extension of sparsity
to matrix-valued data). Our aim is to provide a unified treatment of all these
regularizations under a single umbrella, namely the theory of partial
smoothness. This framework is very general and accommodates all low-complexity
regularizers just mentioned, as well as many others. Partial smoothness turns
out to be the canonical way to encode low-dimensional models that can be linear
spaces or more general smooth manifolds. This review is intended to serve as a
one stop shop toward the understanding of the theoretical properties of the
so-regularized solutions. It covers a large spectrum including: (i) recovery
guarantees and stability to noise, both in terms of -stability and
model (manifold) identification; (ii) sensitivity analysis to perturbations of
the parameters involved (in particular the observations), with applications to
unbiased risk estimation ; (iii) convergence properties of the forward-backward
proximal splitting scheme, that is particularly well suited to solve the
corresponding large-scale regularized optimization problem
1954: Abilene Christian College Bible Lectures - Full Text
Preface
The 1954 Abilene Christian College Lectureship was one of the best attended and most successful in the history of the school. Considerable interest was manifested in the timely theme, “Overcoming Dangerous Tendencies,” and in the two special topics, “Ways and Means of Doing Mission Work,” and “Caring For Widows and Orphans.” The reports from the mission fields were highly stimulating, and all in all, the speeches were unusually high caliber. The Panel Discussions were also on timely subjects and well presented. They received a warm response, as did also the thirty classes that were conducted each day. These classes were taught by persons expert in their particular fields, and covered a wide range of interests to the faithful, working Christian. We at Abilene Christian College predict for this book of Lectures a wide and hearty reception, and believe that its reading will issue in profit to the individual and to the church at large.
J. D. Thomas
Lectureship Directo
Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector
A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results
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