2,403 research outputs found
Novelty Forms: A Satire
Late in the last century, forms (solid crossword arrays with various geometrical outlines) were frequently found in puzzle columns in magazines and newspapers. Constructors soon tired of standard outlines such as squares, diamonds and pyramids, and developed a variety of more exotic ones: stars, crosses, pentagons, enneagons, hurglasses and the like. Two hundred and nine different shapes (including minor variants) can, in fact, be found in the 1906 Key to Puzzledom, a guide to the best in word puzzle literature up to that time. Alas, every excess creates its own reaction; the following satire is an abridgement of an article published by \u27Amaranth\u27 in the Enigma in April, 1924
INTEGRATED ASSESSMENT OF ENVIRONMENTAL EFFECTS FROM AGRICULTURAL PRODUCTION
Agriculture's impact on the environment is a complex research problem. A challenge to future economic research is to account for the interrelationship between agricultural production activities, soil productivity, erosion, and water quality. It will become increasingly important to determine not only the economic consequences, but also the environmental effectiveness of alternative policies aimed at improving resource use and quality. The application of biophysical simulation models to environmental quality problems provides a means to better understand the complex interaction between agricultural production and environmental quality.Environmental Economics and Policy,
A Complexity View of Rainfall
We show that rain events are analogous to a variety of nonequilibrium
relaxation processes in Nature such as earthquakes and avalanches. Analysis of
high-resolution rain data reveals that power laws describe the number of rain
events versus size and number of droughts versus duration. In addition, the
accumulated water column displays scale-less fluctuations. These statistical
properties are the fingerprints of a self-organized critical process and may
serve as a benchmark for models of precipitation and atmospheric processes.Comment: 4 pages, 5 figure
"GREEN TAXES": IMPACTS ON NATIONAL INCOME, SOCIAL WELFARE, AND ENVIRONMENTAL QUALITY
Two taxation schemes were designed to be included in a multi-regional multi-sectoral General Equilibrium model for reducing the use of commercial fertilizers, with the goal of alleviating surface water pollution. Under the 500% tax rate, results showed that 0.1% of the national income was given up in order to exchange for a 3% reduction in the fertilizer application used as an intermediate input. Furthermore environmental quality would be improved by 3%, if a linear relationship existed between the changes in intermediate fertilizer use and the improvement in environmental quality.Environmental Economics and Policy,
On two 10th order mock theta identities
We give short proofs of conjectural identities due to Gordon and McIntosh
involving two 10th order mock theta functions.Comment: 5 pages, to appear in the Ramanujan Journa
Gradient-limited surfaces
A simple scenario of the formation of geological landscapes is suggested and
the respective lattice model is derived. Numerical analysis shows that the
arising non-Gaussian surfaces are characterized by the scale-dependent Hurst
exponent, which varies from 0.7 to 1, in agreement with experimental data.Comment: 4 pages, 5 figure
Can the palatability of healthy, satiety-promoting foods increase with repeated exposure during weight loss?
Repeated exposure to sugary, fatty, and salty foods often enhances their appeal. However, it is unknown if exposure influences learned palatability of foods typically promoted as part of a healthy diet. We tested whether the palatability of pulse containing foods provided during a weight loss intervention which were particularly high in fiber and low in energy density would increase with repeated exposure. At weeks 0, 3, and 6, participants (n = 42; body mass index (BMI) 31.2 ± 4.3 kg/m²) were given a test battery of 28 foods, approximately half which had been provided as part of the intervention, while the remaining half were not foods provided as part of the intervention. In addition, about half of each of the foods (provided as part or not provided as part of the intervention) contained pulses. Participants rated the taste, appearance, odor, and texture pleasantness of each food, and an overall flavor pleasantness score was calculated as the mean of these four scores. Linear mixed model analyses showed an exposure type by week interaction effect for taste, texture and overall flavor pleasantness indicating statistically significant increases in ratings of provided foods in taste and texture from weeks 0 to 3 and 0 to 6, and overall flavor from weeks 0 to 6. Repeated exposure to these foods, whether they contained pulses or not, resulted in a ~4% increase in pleasantness ratings. The long-term clinical relevance of this small increase requires further study.T32 AT000815 - NCCIH NIH HH
Mandelbrot's stochastic time series models
I survey and illustrate the main time series models that Mandelbrot introduced into time series analysis in the 1960s and 1970s. I focus particularly on the members of the additive fractional stable family including Lévy flights and fractional Brownian motion (fBm), noting some of the less well‐known aspects of this family, such as the cases when the self‐similarity exponent H and the Hurst exponent J differ. I briefly discuss the role of multiplicative models in modeling the physics of cascades. I then recount the still little‐known story of Mandelbrot's work on fractional renewal models in the late 1960s, explaining how these differ from their more familiar fBm counterpart and form a “missing link” between fBm and the problem of random change points. I conclude by highlighting the frontier problem of damped fractional models
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