14,934 research outputs found
Error evaluation for difference approximations to ordinary differential equations
Method involves relationships between errors introduced by using finite sampling rates and parameters describing specific numerical method used. Procedurre is used in design and analysi of digital filters and simulators
Sampling errors in closed loop hybrid computer programs
Sampling errors in closed loop hybrid computer program
Errors in hybrid computers
Method is described for reduction of error components in numerical integration, sampling with zero hold order, and execution time delay
Hybrid computer techniques for solving partial differential equations
Techniques overcome equipment limitations that restrict other computer techniques in solving trivial cases. The use of curve fitting by quadratic interpolation greatly reduces required digital storage space
The AFGL absolute gravity program
A brief discussion of the AFGL's (Air Force Geophysics Laboratory) program in absolute gravity is presented. Support of outside work and in-house studies relating to gravity instrumentation are discussed. A description of the current transportable system is included and the latest results are presented. These results show good agreement with measurements at the AFGL site by an Italian system. The accuracy obtained by the transportable apparatus is better than 0.1 microns sq sec 10 microgal and agreement with previous measurements is within the combined uncertainties of the measurements
The information needs of children having clinical procedures in hospital: Will it hurt? Will I feel scared? What can I do to stay calm?
Moving I`iwi (Vestiaria coccinea) as a Surrogate for Future Translocations of Endangered `Akohekohe (Palmeria dolei)
Translocations often play an important role in the recovery of endangered species. To
assess feasibility for translocation of endangered `Akohekohe (Palmeria dolei), we
conducted an experimental translocation of I`iwi (Vestiaria coccinea) from east to west
Maui. Mist-netting, veterinary screening of candidate birds, and helicopter transport of
healthy I`iwi were successful, resulting in no injuries or mortalities. Translocated birds
were assigned to two types of release. Hard release birds were radio tagged and released
on the day of translocation. In contrast, soft release birds were held in large cages for 7
days and fed artificial nectar. During holding soft release I`iwi feeding rates, fecal
production, and mass were monitored. Soft release birds suffered 33% mortality during
the holding period. At the end of the holding period, soft release survivors were outfitted
with a radio transmitter and released. All translocated I`iwi were followed by radio
telemetry for an average of 21 days. Once released, soft release birds showed higher
rates of movement, possibly reflecting conflict with established hard released I`iwi. Our
results suggest that translocation efforts for wild `Akohekohe will be successful if hard
release protocols are followed
Dipolar Bose gases: Many-body versus mean-field description
We characterize zero-temperature dipolar Bose gases under external spherical
confinement as a function of the dipole strength using the essentially exact
many-body diffusion Monte Carlo (DMC) technique. We show that the DMC energies
are reproduced accurately within a mean-field framework if the variation of the
s-wave scattering length with the dipole strength is accounted for properly.
Our calculations suggest stability diagrams and collapse mechanisms of dipolar
Bose gases that differ significantly from those previously proposed in the
literature
The maximum density droplet to lower density droplet transition in quantum dots
We show that, Landau level mixing in two-dimensional quantum dot wave
functions can be taken into account very effectively by multiplying the exact
lowest Landau level wave functions by a Jastrow factor which is optimized by
variance minimization. The comparison between exact diagonalization and fixed
phase diffusion Monte Carlo results suggests that the phase of the many-body
wave functions are not affected much by Landau level mixing. We apply these
wave functions to study the transition from the maximum density droplet state
(incipient integer quantum Hall state with angular momentum L=N(N-1)/2) to
lower density droplet states (L>N(N-1)/2).Comment: 8 pages, 5 figures, accepted for publication in Phys. Rev.
Difference equations to approximate ordinary differential equations
Difference equations for approximating ordinary differential equation
- …