23,757 research outputs found
New results on interference effects and correlations
New results on interface effects and correlations are reviewed, including
Fermi-Dirac and Bose-Einstein correlations in hadronic Z0 decays at LEP1.Comment: 3 pages, 3 figures, ICHEP conference, Tampere, July 199
Experimental study and evaluation of radioprotective drugs
Experimental study evaluates radioprotective drugs administered before exposure either orally or intravenously. Specifically studied are the sources of radiation, choice of radiation dose, choice of animals, administration of drugs, the toxicity of protective agents and types of protective drug
Yellowstone National Park mapping from ERTS-1 computer compatible tapes
There are no author-identified significant results in this report
Terrain classification maps of Yellowstone National Park
A cooperative ERTS-1 investigation involving U. S. Geological Survey, National Park Service, and Environmental Research Institure of Michigan (ERIM) personnel has as its goal the preparation of terrain classification maps for the entire Yellowstone National Park. Excellent coverage of the park was obtained on 6 August 1972 (frame 1015-17404). Preliminary terrain classification maps have been prepared at ERIM by applying multispectral pattern recognition techniques to ERTS-MSS digital taped data. The color coded terrain maps are presented and discussed. The discussion includes qualitative and quantitative accuracy estimates and discussion of processing techniques
PREDICTING OUTPUT FROM SEEMINGLY UNRELATED AREA AND YIELD EQUATIONS
Crop output can be defined as the product of area sown and yield. Given the existence of separate equations for explaining and predicting area sown and yield, in this paper we suggest predictors for output and derive expressions for the standard errors of the predictors. The methodology is applied to wheat production in the Corrigin Shire of Western Australia.Predicting a product, standard error of prediction, Crop Production/Industries,
Calculation of Elastic Green's Functions for Lattices with Cavities
In this Brief Report, we present an algorithm for calculating the elastic
Lattice Greens Function of a regular lattice, in which defects are created by
removing lattice points. The method is computationally efficient, since the
required matrix operations are on matrices that scale with the size of the
defect subspace, and not with the size of the full lattice. This method allows
the treatment of force fields with multi-atom interactions.Comment: 3 pages. RevTeX, using epsfig.sty. One figur
A simple derivation of the electromagnetic field of an arbitrarily moving charge
The expression for the electromagnetic field of a charge moving along an
arbitrary trajectory is obtained in a direct, elegant, and Lorentz invariant
manner without resorting to more complicated procedures such as differentiation
of the Lienard-Wiechert potentials. The derivation uses arguments based on
Lorentz invariance and a physically transparent expression originally due to
J.J.Thomson for the field of a charge that experiences an impulsive
acceleration.Comment: The following article has been accepted by the American Journal of
Physics. After it is published, it will be found at
http://scitation.aip.org/ajp; 12 pages, 1 figur
Sensitivity-analysis method for inverse simulation application
An important criticism of traditional methods of inverse simulation that are based on the Newton–Raphson algorithm is that they suffer from numerical problems. In this paper these problems are discussed and a new method based on sensitivity-analysis theory is developed and evaluated. The Jacobian matrix may be calculated by solving a sensitivity equation and this has advantages over the approximation methods that are usually applied when the derivatives of output variables with respect to inputs cannot be found analytically. The methodology also overcomes problems of input-output redundancy that arise in the traditional approaches to inverse simulation. The sensitivity- analysis approach makes full use of information within the time interval over which key quantities are compared, such as the difference between calculated values and the given ideal maneuver after each integration step. Applications to nonlinear HS125 aircraft and Lynx helicopter models show that, for this sensitivity-analysis method, more stable and accurate results are obtained than from use of the traditional Newton–Raphson approach
Why charges go to the surface: a generalized Thomson problem
We study a generalization of a Thomson problem of n particles confined to a
sphere and interacting by a 1/r^g potential. It is found that for g \le 1 the
electrostatic repulsion expels all the charges to the surface of the sphere.
However for g>1 and n>n_c(g) occupation of the bulk becomes energetically
favorable. It is curious to note that the Coulomb law lies exactly on the
interface between these two regimes
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