A study of some nine-element decision rules

A nine-element rule is one that makes a classification decision for each pixel based on data from that pixel and its eight immediate neighbors. Three such rules, all fast and simple to use, are defined and tested. All performed substantially better on field interiors than the best one-point rule. Qualitative results indicate that fine detail and contradictory testimony tend to be overlooked by the rules

Effect of anode ring arrangement on the spectroscopic characteristics of the NASA Lewis bumpy torus plasma

The modified Penning discharge in the NASA Lewis Bumpy Torus is normally produced by an anode ring at high voltage in each of the 12 magnetic mirror midplanes. For this investigation, the plasma was run with 12, 6, 3, and 1 anode rings. When 3 anode rings were used, the spectroscopically determined relative electron density and mean ion residence time increase by factors of 10 and 5, respectively, in one mode of operation. The discharge is observed to uniformly fill all bumps around the torus regardless of the anode arrangement and number. A plasma density on axis of 10 to the 11th power cm/3 is estimated for the 3 anode case in one mode of operation based on an observed discharge current to ion loss rate correlation and a measured mean ion residence time of .5 msec

RESEARCH IN AGRICULTURAL ECONOMICS--IS ANYONE LISTENING? DISCUSSION

Research and Development/Tech Change/Emerging Technologies,

FARM PROGRAMS, PESTICIDE USE, AND SOCIAL COSTS

Environmental Economics and Policy,

Commercial air transport hazard warning and avoidance system. Volume 1 - Summary Final report

Operational requirements for commercial air transport hazard warning and avoidance syste

Use of a transcendental approximation in transient conduction analysis

Variation method applied to transient thermal conductivity in semiinfinite slab with nonlinear boundary conditio

Use of a transcendental approximation in transient conduction analysis

Boundary condition solution and transcendental approximation for transient heat conduction proble

The Photometry of Undersampled Point Spread Functions

An undersampled point spread function may interact with the microstructure of a solid-state detector such that the total flux detected can depend sensitively on where the PSF center falls within a pixel. Such intra-pixel sensitivity variations will not be corrected by flat field calibration and may limit the accuracy of stellar photometry conducted with undersampled images, as are typical for Hubble Space Telescope observations. The total flux in a stellar image can vary by up to 0.03 mag in F555W WFC images depending on how it is sampled, for example. For NIC3, these variations are especially strong, up to 0.39 mag, strongly limiting its use for stellar photometry. Intra-pixel sensitivity variations can be corrected for, however, by constructing a well-sampled PSF from a dithered data set. The reconstructed PSF is the convolution of the optical PSF with the pixel response. It can be evaluated at any desired fractional pixel location to generate a table of photometric corrections as a function of relative PSF centroid. A caveat is that the centroid of an undersampled PSF can also be affected by the pixel response function, thus sophisticated centroiding methods, such as cross-correlating the observed PSF with its fully-sampled counterpart, are required to derive the proper photometric correction.Comment: 20 pages, 14 postscript figures, submitted to the PAS

Financial Conditions on U.S. Cotton Farms

For the last three years, U.S. cotton producers have been heavily dependent on ad hoc emergency disaster and market loss assistance to cash flow their operations. They have not been alone. Wheat, feed grains, oilseeds and rice producers have also been faced with low commodity prices, adverse weather and the need for substantial government assistance. Price support and direct payments by CCC for fiscal years 1998-2000 averaged $17.5 billion per year (USDA Ag Outlook). Has U.S. program crop agriculture turned the corner or will additional government payments likely be needed to sustain a vulnerable sector? This paper will focus on the outlook for the Agricultural and Food Policy Center’s (AFPC’s) representative cotton farms over the period 2001-2005. The results reported herein are drawn from AFPC Working Paper 00-4 which goes into greater depth on all 82 representative farms and ranches modeled by AFPC.Agribusiness, Agricultural and Food Policy, Crop Production/Industries,