2,759 research outputs found
Solar g-mode oscillations: Comparison of SMM-ACRIM and ground-based observations
Progress was made in access to data and in developing programs for its analysis. The difficulties in completing the work in the planned time can be traced to several factors. The correction of the Stanford oscillation using gridded intensity data was not successful. It was concluded that due to poor continuity of the 1985 and 1986 data due to clouds, that a joint analysis with the ACRIM data (best solar oscillation data to date) on the summer 1987 observations should be performed. The 1988 Stanford oscillation data are being examined and the cross comparison of the ACRIM spectrum with the Standford spectrum for 1987 in the g-mode regime will shortly begin
Review of observations relevant to solar oscillations
Recent solar oscillation observations and methods used are described. Integrated or almost integrated sunlight (Sun as a star observation) was observed. The most certain observations are in the 5 minute range. The p-mode and g-mode oscillations are expected from 3 to more than 300 minutes. The possible period ranges are described into the three intervals: (1) the 5 minute range for which the most dramatic and certain results are reported; (2) the 10 to 20 minute range for which solar diameter oscillations are reported; and (3) the 160 minute oscillation found in velocity and several other quantities
Annual and solar-magnetic-cycle variations in the interplanetary magnetic field, 1926-1971
The analysis of forty-five years of inferred interplanetary magnetic field polarity shows an annual variation and a variation of about twenty years, associated here with the solar magnetic cycle. On the average the phase of the annual variation of the interplanetary field changes about 2 and 2/3 years after sunspot maximum, i.e. for about ten consecutive years the predominant polarity of the interplanetary field is away from the sun during the six-month interval in which the earth is at southern heliographic latitudes. Then a change of phase occurs so that for about the next ten years the predominant polarity is toward the sun, while the earth is at southern heliographic latitudes. The annual variation changes its predominant polarity within a few days of the times when the heliographic latitude of the earth is zero
Pseudo-rip: Cosmological models intermediate between the cosmological constant and the little rip
If we assume that the cosmic energy density will remain constant or strictly
increase in the future, then the possible fates for the universe can be divided
into four categories based on the time asymptotics of the Hubble parameter
H(t): the cosmological constant, for which H(t) = constant, the big rip, for
which H(t) goes to infinity at finite time, the little rip, for which H(t) goes
to infinity as time goes to infinity, and the pseudo-rip, for which H(t) goes
to a constant as time goes to infinity. Here we examine the last of these
possibilities in more detail. We provide models that exemplify the pseudo-rip,
which is an intermediate case between the cosmological constant and the little
rip. Structure disintegration in the pseudo-rip depends on the model
parameters. We show that pseudo-rip models for which the density and Hubble
parameter increase monotonically can produce an inertial force which does not
increase monotonically, but instead peaks at a particular future time and then
decreases.Comment: 4 pages, 2 figures, title changed to agree with published versio
The equatorial rotation velocity of the photosphere is measured to be the same as sunspots
The equatorial rotation rate of the photosphere was measured at effect data. It was found that scattered light has a large influence and must be taken into account properly. When this was done it was found that the rotation rate from Doppler shifts agreed very well with the rate found for sunspots. Short-term fluctuations in rotation rate (i.e. from day to day) were less than plus or minus 15 m/s and were thus within observational errors
An Analysis of Information Technology Training Effectiveness: The Impact on Trainee Reactions, Learning, and Performance
Through its Global Reach , the Air Force operates globally and in environments that are potentially dynamic, competitive, and lethal. Information Dominance has assumed a central role in such environments. In order to achieve Information Dominance, the Air Force must have trained and skilled personnel able to perform highly intensive activities using information technologies. Therefore, it is crucial that information technology training be able to deliver the requisite skills personnel need to attain and sustain performance on these systems. The importance of training gives rise to the need to determine how information technology training can be continually improved to maximize return on training dollars and produce adequately trained personnel. Evaluation of information technology training provides such an avenue by providing information that assesses how well the training program is meeting its goals, both during training and on-the-job. This thesis analyzes the impact of information technology training on trainee reactions, learning, and performance via an information technology training program for a global Air Force command and control (C2) system. Trainee confidence, perceptions, attitudes, test scores, and performance with regard to the C2 system are analyzed to discover if the training positively increases any of these factors. Among the most important results presented is the degree of trainee on-the-job performance improvement using the system following training. With training\u27s relationship to these factors clearly outlined and understood, information technology training courses can be improved and resources allocated to those courses that consistently produce skilled personnel who can perform using information technology
A physical mechanism for the prediction of the sunspot number during solar cycle 21
On physical grounds it is suggested that the sun's polar field strength near a solar minimum is closely related to the following cycle's solar activity. Four methods of estimating the sun's polar magnetic field strength near solar minimum are employed to provide an estimate of cycle 21's yearly mean sunspot number at solar maximum of 140 plus or minus 20. This estimate is considered to be a first order attempt to predict the cycle's activity using one parameter of physical importance
- …