38,360 research outputs found
Evolving macro-actions for planning
Domain re-engineering through macro-actions (i.e. macros) provides one potential avenue for research into learning for planning. However, most existing work learns macros that are reusable plan fragments and so observable from planner behaviours online or plan characteristics offline. Also, there are learning methods that learn macros from domain analysis. Nevertheless, most of these methods explore restricted macro spaces and exploit specific features of planners or domains. But, the learning examples, especially that are used to acquire previous experiences, might not cover many aspects of the system, or might not always reflect that better choices have been made during the search. Moreover, any specific properties are not likely to be common with many planners or domains. This paper presents an offline evolutionary method that learns macros for arbitrary planners and domains. Our method explores a wider macro space and learns macros that are somehow not observable from the examples. Our method also represents a generalised macro learning framework as it does not discover or utilise any specific structural properties of planners or domains
A study of a non-deepening tropical disturbance
Data from research vessel, instrumented research aircraft, and Tiros VI and Tiros VII SATELLITES to study nondeepening tropical disturbanc
Aperture synthesis for microwave radiometers in space
A technique is described for obtaining passive microwave measurements from space with high spatial resolution for remote sensing applications. The technique involves measuring the product of the signal from pairs of antennas at many different antenna spacings, thereby mapping the correlation function of antenna voltage. The intensity of radiation at the source can be obtained from the Fourier transform of this correlation function. Theory is presented to show how the technique can be applied to large extended sources such as the Earth when observed from space. Details are presented for a system with uniformly spaced measurements
Space shuttle: Basic hypersonic force data for Grumman delta wing orbiter configurations ROS-NB1 and ROS-WB1
Hypervelocity wind tunnel tests at Mach 10 of delta wing space shuttle model
Experimental proposal for accurate determination of the phase relaxation time and testing a formation of thermalized non-equilibrated matter in highly excited quantum many-body systems
We estimate how accurate the phase relaxation time of quantum many-body
systems can be determined from data on forward peaking of evaporating protons
from a compound nucleus. The angular range and accuracy of the data needed for
a reliable determination of the phase relaxation time are evaluated. The
general method is applied to analyze the inelastic scattering of 18 MeV protons
from Pt for which previously measured double differential cross sections for
two angles in the evaporating domain of the spectra show a strong forward
peaking. A new experiment for an improved determination of the phase relaxation
time is proposed. The experiment is also highly desirable for an accurate test
of a formation of thermalized non-equilibrated matter in quantum many-body
systems.Comment: 5 pages, 3 figure
The effect of electromagnetic properties of neutrinos on the photon-neutrino decoupling temperature
We examine the impact of electromagnetic properties of neutrinos on the
annihilation of relic neutrinos with ultra high energy cosmic neutrinos for the
process. For this process, photon-neutrino
decoupling temperature is calculated via effective lagrangian model beyond the
standard model. We find that photon-neutrino decoupling temperature can be
importantly reduced below the QCD phase transition with the model independent
analysis defining electromagnetic properties of neutrinos.Comment: 12 pages, 3 figures, published versio
Flocking Regimes in a Simple Lattice Model
We study a one-dimensional lattice flocking model incorporating all three of
the flocking criteria proposed by Reynolds [Computer Graphics vol.21 4 (1987)]:
alignment, centring and separation. The model generalises that introduced by O.
J. O' Loan and M. R. Evans [J. Phys. A. vol. 32 L99 (1999)]. We motivate the
dynamical rules by microscopic sampling considerations. The model exhibits
various flocking regimes: the alternating flock, the homogeneous flock and
dipole structures. We investigate these regimes numerically and within a
continuum mean-field theory.Comment: 24 pages 7 figure
Force chain splitting in granular materials: a mechanism for large scale pseudo-elastic behaviour
We investigate both numerically and analytically the effect of strong
disorder on the large scale properties of the hyperbolic equations for stresses
proposed in \protect\cite{bcc,wcc}. The physical mechanism that we model is the
local splitting of the force chains (the characteristics of the hyperbolic
equation) by packing defects. In analogy with the theory of light diffusion in
a turbid medium, we propose a Boltzmann-like equation to describe these
processes. We show that, for isotropic packings, the resulting large scale
effective equations for the stresses have exactly the same structure as those
of an elastic body, despite the fact that no displacement field needs to be
introduced at all. Correspondingly, the response function evolves from a two
peak structure at short scales to a broad hump at large scales. We find,
however, that the Poisson ratio is anomalously large and incompatible with
classical elasticity theory that requires the reference state to be
thermodynamically stable.Comment: 7 pages, 6 figures, An incorrect definition of the Poisson ratio in
dimensions not equal to 3 was amended. The conclusions are unchange
Development of tunable high pressure CO2 laser for lidar measurements of pollutants and wind velocities
The problem of laser energy extraction at a tunable monochromatic frequency from an energetic high pressure CO2 pulsed laser plasma, for application to remote sensing of atmospheric pollutants by Differential Absorption Lidar (DIAL) and of wind velocities by Doppler Lidar, was investigated. The energy extraction principle analyzed is based on transient injection locking (TIL) at a tunable frequency. Several critical experiments for high gain power amplification by TIL are presented
Detection of Prolonged Diapause of Northern Corn Rootworm in Michigan (Coleoptera: Chrysomelidae)
Prolonged diapause of northern corn rootworm, while known from other Midwestern states, has not previously been reported in Michigan. Populations of northern corn rootworm, (Diabrotica barberi) from two first-year corn fields in Genesee County, Michigan were examined for prolonged egg diapause. Pro- longed diapause was suspected in these populations due to an unusually high proportion of northern versus western corn rootworms in these fields. Eggs obtained from females collected at these sites were reared in the laboratory for two years. The presence of the prolonged diapause trait was confirmed in one population by eggs which hatched following two simulated winters (7.3%). None of the eggs m the second population hatched following the second chill period, however, some eggs in this population remained in apparent diapause at the end of two years. The potential for using observed population shifts in favor of D. barberi as an early warning of the expansion of prolonged diapause in a population is discussed
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