24,666 research outputs found
Discussion: What Have We Learned from the New Suite of Risk Management Programs of the Food, Conservation, and Energy Act of 2008?
New revenue-based support programs in the 2008 Farm Bill represent a fundamental shift in farm programs and risk management decision-making. However, complexity, uncertainty, economics, and, arguably, an incomplete analysis of the new Average Crop Revenue Election (ACRE) program all contributed to low enrollment in the new program in 2009. An effective analysis of ACRE should consider farm programs as part of an integrated risk management portfolio, including crop insurance, marketing, and other risk management tools as opposed to a separate lottery program. Improving this integration could be one of the most significant consequences of the 2008 Farm Bill.farm bill, commodity programs, risk management, Agribusiness, Agricultural and Food Policy, Agricultural Finance, Farm Management, Land Economics/Use, Political Economy, Public Economics, Risk and Uncertainty, Q18,
Updating the Farm Bill Safety Net in an Expanding Sea of Risk
Agricultural and Food Policy, Food Consumption/Nutrition/Food Safety, H10,
What Fraction of the Young Clusters in the Antennae Galaxies are "Missing"?
A reexamination of the correspondence between 6 cm radio continuum sources
and young star clusters in the Antennae galaxies indicates that 85 % of the
strong thermal sources have optical counterparts, once the optical image is
shifted 1.2 arcsec to the southwest. A sample of 37 radio-optical matches are
studied in detail showing correlations between radio properties and a variety
of optical characteristics. There is a strong correlation between the radio
flux and the intrinsic optical brightness. In particular, the brightest radio
source is also the intrinsically brightest optical cluster (WS80). It is also
the most extincted cluster in the sample, the strongest CO source and the
strongest 15 micron source . Furthermore, the brightest ten radio sources are
all amongst the youngest clusters with ages in the range 0 - 4 Myr and
extinctions from A_V = 0.5 to 7.6 mag (with a median value of 2.6 mag). Only a
few of the very red clusters originally discovered by Whitmore & Schweizer are
radio sources, contrary to earlier suggestions. Finally, a new hybrid method of
determining cluster ages has been developed using both UBVI colors and H_alpha
equivalent widths to break the age-reddening degeneracy.Comment: 51 pages, 13 postscript figures, LaTex. To appear in the Astronomical
Journal, 124, 2002, Septembe
Vibration limiting of rotors by feedback control
Experimental findings of a three mass rotor with four channels of feedback control are reported. The channels are independently controllable with force being proportional to the velocity and/or instantaneous displacement from equilibrium of the shaft at the noncontacting probe locations (arranged in the vertical and horizontal attitudes near the support bearings). The findings suggest that automatic feedback control of rotors is feasible for limiting certain vibration levels. Control of one end of a rotor does afford some predictable vibration limiting of the rotor at the other end
Photon signature analysis using template matching
We describe an approach to detect improvised explosive devices (IEDs) by using a template matching procedure. This approach relies on the signature due to backstreaming ? photons from various targets. In this work we have simulated cylindrical targets of aluminum, iron, copper, water and ammonium nitrate (nitrogen-rich fertilizer). We simulate 3.5 MeV source photons distributed on a plane inside a shielded area using Monte Carlo N-Particle (MCNP TM) code version 5 (V5). The 3.5 MeV source gamma rays yield 511 keV peaks due to pair production and scattered gamma rays. In this work, we simulate capture of those photons that backstream, after impinging on the target element, toward a NaI detector. The captured backstreamed photons are expected to produce a unique spectrum that will become part of a simple signal processing recognition system based on the template matching method. Different elements were simulated using different sets of random numbers in the Monte Carlo simulation. To date, the sum of absolute differences (SAD) method has been used to match the template. In the examples investigated, template matching was found to detect all elements correctly
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