1,954 research outputs found
Relative performance of 8.5-GHz and 32-GHz telemetry links on the basis of total data return per pass
The performance of X-band (8.5-GHz) and 32-GHz telemetry links is compared on the basis of the total data return per DSN station pass. Differences in spacecraft transmitter efficiency, transmit circuit loss, and transmitting antenna area efficiency and pointing loss are not considered in these calculations. Thus, the performance differentials calculated in this memo are those produced by a DSN 70-m station antenna gain and clear weather receiving system noise temperature and by weather. These calculations show that, assuming mechanical compensation of the DSN 70-m antenna for 32-GHz operation, a performance advantage for 32 GHz over X-band of 8.2 dB can be achieved for at least one DSN station location. Even if only Canberra and Madrid are used, a performance advantage of 7.7 dB can be obtained for at least one DSN station location. A system using a multiple beam feed (electronic compensation) should achieve similar results
Effect of interference on a binary communication channel using known signals
Sinusoidal and Gaussian interference effects on binary communication channel using known signals in white random nois
Asymptotic structure of perturbative series for lepton decay observables: corrections
In a previous paper we performed an analysis of asymptotic structure of
perturbation theory series for semileptonic -lepton decays in massless
limit. We extend our analysis to the Cabibbo suppressed decay
modes of the lepton. In particular we address the problem of
corrections to theoretical formulas. The properties of the asymptotic behavior
of the finite order perturbation theory series for the coefficient functions of
the corrections are studied.Comment: 25 page
Overcoming system-size limitations in spin glasses
In order to overcome the limitations of small system sizes in spin-glass
simulations, we investigate the one-dimensional Ising spin chain with power-law
interactions. The model has the advantage over traditional higher-dimensional
Hamiltonians in that a large range of system sizes can be studied. In addition,
the universality class of the model can be changed by tuning the power law
exponent, thus allowing us to scan from the mean-field to long-range and
short-range universality classes. We illustrate the advantages of this model by
studying the nature of the spin glass state where our results hint towards a
replica symmetry breaking scenario. We also compute ground-state energy
distributions and show that mean-field and non-mean-field models are
intrinsically different.Comment: 5 pages, 2x2 figures, proceedings of the 2004 SPDSA Conference in
Hayama, Japan, July 12 - 15, 200
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