18,208 research outputs found
Transforms for minimal surfaces in the 5-sphere.
We define two transforms between minimal surfaces with non-circular ellipse of curvature in the 5-sphere, and show how this enables us to construct, from one such surface, a sequence of such surfaces. We also use the transforms to show how to associate to such a surface a corresponding ruled minimal Lagrangian submanifold of complex projective 3-space, which gives the converse of a construction considered in a previous paper, and illustrate this explicitly in the case of bipolar minimal surfaces
Annotated List of Crane Flies (Diptera: Tipulidae) From Mentor Marsh, Lake County, Ohio
Sixty-one species of Tipulidae, one species of Ptychopteridae, two species of Trichoceridae, and one species of Anisopodidae are recorded for Mentor Marsh and adjacent woodlands
Spectro-Perfectionism: An Algorithmic Framework for Photon Noise-Limited Extraction of Optical Fiber Spectroscopy
We describe a new algorithm for the "perfect" extraction of one-dimensional
spectra from two-dimensional (2D) digital images of optical fiber
spectrographs, based on accurate 2D forward modeling of the raw pixel data. The
algorithm is correct for arbitrarily complicated 2D point-spread functions
(PSFs), as compared to the traditional optimal extraction algorithm, which is
only correct for a limited class of separable PSFs. The algorithm results in
statistically independent extracted samples in the 1D spectrum, and preserves
the full native resolution of the 2D spectrograph without degradation. Both the
statistical errors and the 1D resolution of the extracted spectrum are
accurately determined, allowing a correct chi-squared comparison of any model
spectrum with the data. Using a model PSF similar to that found in the red
channel of the Sloan Digital Sky Survey spectrograph, we compare the
performance of our algorithm to that of cross-section based optimal extraction,
and also demonstrate that our method allows coaddition and foreground
estimation to be carried out as an integral part of the extraction step. This
work demonstrates the feasibility of current- and next-generation multi-fiber
spectrographs for faint galaxy surveys even in the presence of strong night-sky
foregrounds. We describe the handling of subtleties arising from fiber-to-fiber
crosstalk, discuss some of the likely challenges in deploying our method to the
analysis of a full-scale survey, and note that our algorithm could be
generalized into an optimal method for the rectification and combination of
astronomical imaging data.Comment: 9 pages, 4 figures, emulateapj; minor corrections and clarifications;
to be published in the PAS
A study of methods to predict and measure the transmission of sound through the walls of light aircraft
The objectives are: measurement of dynamic properties of acoustical foams and incorporation of these properties in models governing three-dimensional wave propagation in foams; tests to measure sound transmission paths in the HP137 Jetstream 3; and formulation of a finite element energy model. In addition, the effort to develop a numerical/empirical noise source identification technique was completed. The investigation of a design optimization technique for active noise control was also completed. Monthly progress reports which detail the progress made toward each of the objectives are summarized
Picture this: researching child workers
Visual methods such as photography are under-used in the active process of sociological research. As rare as visual methods are, it is even rarer for the resultant images to be made by rather than of research participants. Primarily, the paper explores the challenges and contradictions of using photography within a multi-method approach. We consider processes for analysing visual data, different ways of utilising visual methods in sociological research, and the use of primary and secondary data, or, simple illustration versus active visual exploration of the social. The question of triangulation of visual data against text and testimony versus a stand-alone approach is explored in depth
Control of Blown Pack Spoilage in Vacuum Packaged Meat
End of project reportBlown pack spoilage (BPS) represents a significant commercial loss to Irish meat processors. This research discovered that the organisms causing BPS are ubiquitous in the abattoir environment, making eradication very difficult. The risk of BPS is best managed through a process of regular treatment of plant and equipment with a sporicidal agent such as peroxyacetic acid, good hygiene to minimise carcass contamination and removal of the heat shrinkage stage during vacuum packaging as this activates the spores and reduces the time to spoilage.National Development Plan 2007-201
Explorations in price (un)fairness.
Consumers may use multiple reference points-including cost of goods, past prices, and competitive prices-to judge price fairness. Across a series of studies we show that consumers are inclined to overestimate profits, often to an extreme extent. We further demonstrate that prices are perceived to be unfair because consumers fail to take into account vendor costs, underestimate the effects of inflation, and attribute competitive price differences to profits. Potential corrective interventions by marketers-such as cueing costs, providing historical price information, and explaining price differences-were insufficient to eliminate unfairness perceptions. In addition, prices for goods were found to be stickier than prices for services and therefore were especially susceptible to these systematic perceptions of unfairness.Prices; Studies; Costs; Effects;
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