81,877 research outputs found
The remapped particle-mesh advection scheme
We describe the remapped particle-mesh method, a new mass-conserving method
for solving the density equation which is suitable for combining with
semi-Lagrangian methods for compressible flow applied to numerical weather
prediction. In addition to the conservation property, the remapped
particle-mesh method is computationally efficient and at least as accurate as
current semi-Lagrangian methods based on cubic interpolation. We provide
results of tests of the method in the plane, results from incorporating the
advection method into a semi-Lagrangian method for the rotating shallow-water
equations in planar geometry, and results from extending the method to the
surface of a sphere
Attitude ground support system for the solar maximum mission spacecraft
The SMM attitude ground support system (AGSS) supports the acquisition of spacecraft roll attitude reference, performs the in-flight calibration of the attitude sensor complement, supports onboard control autonomy via onboard computer data base updates, and monitors onboard computer (OBC) performance. Initial roll attitude acquisition is accomplished by obtaining a coarse 3 axis attitude estimate from magnetometer and Sun sensor data and subsequently refining it by processing data from the fixed head star trackers. In-flight calibration of the attitude sensor complement is achieved by processing data from a series of slew maneuvers designed to maximize the observability and accuracy of the appropriate alignments and biases. To ensure autonomy of spacecraft operation, the AGSS selects guide stars and computes sensor occultation information for uplink to the OBC. The onboard attitude control performance is monitored on the ground through periodic attitude determination and processing of OBC data in downlink telemetry. In general, the control performance has met mission requirements. However, software and hardware problems have resulted in sporadic attitude reference losses
Recent advances in agroforestry: supporting the transition from conventional to climate-resilient farming
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Weighted cohomology of arithmetic groups
M. Goresky, G. Harder, and R. MacPherson defined weighted cohomologies of
arithmetic groups \Gamma in a real group G, with coefficients in certain local
systems, associated to arbitrary upper and lower weight profiles. The author
shows, using essentially local arguments on the reductive Borel-Serre
compactification, that these cohomologies agree with certain weighted L^2
cohomologies defined by J. Franke. When the rank of G is equal to that of a
maximal compact subgroup, this implies that the cohomologies associated to both
upper and lower middle profiles are both isomorphic to L^2 cohomology.Comment: 32 pages, published version, abstract added in migratio
Using biochar from sewage sludge and other feedstocks in european agroforestry: opportunities and challenges
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Family Life & Life Skills Education for Adolescents: Trivandrum Experience
Adolescence is a period of experimenting, experiencing and expanding. Adolescents need help and guidance in
decision-making, problem solving, critical thinking, developing interpersonal skills, self-awareness, empathy,
coping with stress and managing emotions. The rebelliousness and dislike for parental intrusion usually keeps
parents at bay because teenagers do not relish the idea of help and guidance from parents. However, this may not
always be so. Beneath frequent violent outbursts, sudden mood swings and related interpersonal problems of an
adolescent, there may be a person crying out for professional help. All adolescents need support and guidance.
When parents find it difficult to handle signs of trouble, professional help should be sought at the earliest. Extra
care is needed while offering help to adolescents problems because it is not easy for teenagers to accept the fact
that they need help. Attempts should be made to understand the adolescent, and to safeguard, protect and guide
him/her. The Family Life & Life Skills Education Programme is a good support system for adolescents at the
community level
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