86,666 research outputs found
An Optics Field Site for Auroral Studies
The earlier orbits and ephemerides for the Soviet satellites were not sufficiently
accurate to be very useful in making observations in Alaska. Extrapolations
from our own observations gave better predictions. This merely pointed out the fact
that rough observations of meridian transits at high latitudes will give better values
of the inclination of the orbit than precision observations at low latitudes. Hence,
it was decided to observe visually the meridian transits estimating the altitude by
noting the position with respect to the stars or using crude alidade measurements.
The times of the earlier observations were observed on a watch or clock and the clock
correction obtained from WWV. Later the times were determined with the aid of stop
watches, taking time intervals from WWV signals.
This rather meager program of optical observations of the Soviet satellites was
undertaken to give supplementary data for use of the radio observations, and particularly
to assist in the prediction of position of the satellite so that the 61-foot
radar of Stanford Research Institute could be set accurately enough to observe it
(the beam width at the half-power points is about 3°).
This report contains primarily the visual observations made at the Geophysical
Institute by various members of the staff, and a series of observations by Olaf
Halverson at Nome, Alaska. In addition there is a short discussion of the geometry
of the trajectory, the illumination of a circumpolar satellite, and a note on the
evaluation of Brouwer's moment factors.IGY Project No. 1.14
NSF Grant No. Y/1.14/1771. Introduction -- 2. General Construction -- [3. Operation of Instruments] 3.1 Sky view and location -- 3.2 Supports for instruments -- 3.3 Facilities for each major instrument : a) Hunten scanning spectrometer ; b) IGY patrol spectrograph ; c) College meridian mirror spectrograph ; d) Huet prism spectrograph ; e) Roach scanning photometer ; f) All-sky camera ; g) Future installations -- 4. Auxiliary Facilities : 4.1 Electric power; circuit details ; 4.2 Other services -- 5. SummaryYe
Final-state interactions and superscaling in the semi-relativistic approach to quasielastic electron and neutrino scattering
The semi-relativistic approach to electron and neutrino quasielastic
scattering from nuclei is extended to include final-state interactions.
Starting with the usual non-relativistic continuum shell model, the problem is
relativized by using the semi-relativistic expansion of the current in powers
of the initial nucleon momentum and relativistic kinematics. Two different
approaches are considered for the final-state interactions: the Smith-Wambach
2p-2h damping model and the Dirac-equation-based potential extracted from a
relativistic mean-field plus the Darwin factor. Using the latter the scaling
properties of and cross sections for intermediate
momentum transfers are investigated.Comment: 36 pages, 17 figure
Biochemical, endocrine, and hematological factors in human oxygen tolerance extension: Predictive studies 6
The Predictive Studies VI (Biochemical, endocrine, and hematological factors in human oxygen tolerance extension) Program consisted of two related areas of research activity, integrated in design and performance, that were each based on an ongoing analysis of human organ oxygen tolerance data obtained for the continuous oxygen exposures of the prior Predictive Studies V Program. The two research areas effectively blended broad investigation of systematically varied intermittent exposure patterns in animals with very selective evaluation of specific exposure patterns in man
Native and Non-Native Speaker Judgements on the Quality of Synthesized Speech
The difference between native speakers' and non-native speak- ers' naturalness judgements of synthetic speech is investigated. Similar/difference judgements are analysed via a multidimen- sional scaling analysis and compared to Mean opinion scores. It is shown that although the two groups generally behave in a similar manner the variance of non-native speaker judgements is generally higher. While both groups of subject can clearly distinguish natural speech from the best synthetic examples, the groups' responses to different artefacts present in the synthetic speech can vary
General purpose airborne simulator - Conceptual design report
General purpose airborne simulator with capabilities for model controlled and response feedback types of variable stability operatio
Propagating plane harmonic waves through finite length plates of variable thickness using finite element techniques
An analysis is given using finite element techniques which addresses the propagaton of a uniform incident pressure wave through a finite diameter axisymmetric tapered plate immersed in a fluid. The approach utilized in developing a finite element solution to this problem is based upon a technique for axisymmetric fluid structure interaction problems. The problem addressed is that of a 10 inch diameter axisymmetric fixed plate totally immersed in a fluid. The plate increases in thickness from approximately 0.01 inches thick at the center to 0.421 inches thick at a radius of 5 inches. Against each face of the tapered plate a cylindrical fluid volume was represented extending five wavelengths off the plate in the axial direction. The outer boundary of the fluid and plate regions were represented as a rigid encasement cylinder as was nearly the case in the physical problem. The primary objective of the analysis is to determine the form of the transmitted pressure distribution on the downstream side of the plate
Adaptive Multigrid Algorithm for Lattice QCD
We present a new multigrid solver that is suitable for the Dirac operator in
the presence of disordered gauge fields. The key behind the success of the
algorithm is an adaptive projection onto the coarse grids that preserves the
near null space. The resulting algorithm has weak dependence on the gauge
coupling and exhibits very little critical slowing down in the chiral limit.
Results are presented for the Wilson Dirac operator of the 2d U(1) Schwinger
model.Comment: 4 pages, 2 figure
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