Redundant data management system

Redundant data management system solves problem of operating redundant equipment in real time environment where failures are detected, isolated, and switched in simple manner. System consists of quadruply-redundant computer, input/output control units, and data buses. System inherently contains failure detection, isolation, and switching function

Discovery of hydroxyl and water masers in R Aquarii and H1-36 Arae

We present the first results from an all-sky maser-line survey of symbiotic Miras. Interferometric spectral-line observations of R Aqr and H1-36 Arae have revealed a 22-GHz water maser in the former and 1612-MHz hydroxyl and weak 22-GHz water maser emission from the latter. H1-36 has thus become the first known symbiotic OH/IR star. We have also detected weak OH line emission from the vicinity of R Aqr, but we note that there are small discrepencies between the OH- and H2O-line velocities and positions. These detections demonstrate unequivocally that dust can shield some circumstellar hydroxyl and water molecules from dissociation, even in systems which possess intense local sources of UV. Finally, we discuss some of the implications of these observations. The narrow profile of the water maser in R Aqr means that there may finally be an opportunity to determine the system's orbital parameters. We also point out that high resolution synthesis observations may trace the distribution of dust in H1-36 and R Aqr, possibly throwing light on the mass-loss process in symbiotic Miras and placing constraints on the amount of collimation experienced by UV radiation from their hot, compact companions.Comment: 7 pages; no figures attached; LaTex (MN style); postscript figures via anonymous ftp in /users/ers on astro.caltech.edu; University of Toronto pre-print; ERSRJI

The structure of equivalent 3-separations in a 3-connected matroid

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The structure of 3-connected matroids of path width three

For the abstract of this paper, please see the PDF file

Squarks in Tevatron Dilepton Events ?

We consider unusual events in the CDF and D0 dilepton+jets sample with very high ET(lepton) and ET(missing). It is possible, but very unlikely, that these events originate from top quark pair production; however, they have characteristics that are better accounted for by decays of supersymmetric quarks with mass in the region of 300 GeV.Comment: 5 pages, 2 postscript (eps) figures, uses sprocl.sty (included

A Feasibility Study of the Flare-Cylinder Configuration as a Reentry Body Shape for an Intermediate Range Ballistic Missile

A study has been made of a flare-cylinder configuration to investigate its feasibility as a reentry body of an intermediate range ballistic missile. Factors considered were heating, weight, stability, and impact velocity. A series of trajectories covering the possible range of weight-drag ratios were computed for simple truncated nose shapes of varying pointedness, and hence varying weight-drag ratios. Four trajectories were chosen for detailed temperature computation from among those trajectories estimated to be possible. Temperature calculations were made for both "conventional" (for example, copper, Inconel, and stainless steel) and "unconventional" (for example, beryllium and graphite) materials. Results of the computations showed that an impact Mach number of 0.5 was readily obtainable for a body constructed from conventional materials. A substantial increase in subsonic impact velocity above a Mach number of 0.5 was possible without exceeding material temperature limits. A weight saving of up to 134 pounds out of 822 was possible with unconventional materials. This saving represents 78 percent of the structural weight. Supersonic impact would require construction of the body from unconventional materials but appeared to be well within the range of attainability

Spiked oscillators: exact solution

A procedure to obtain the eigenenergies and eigenfunctions of a quantum spiked oscillator is presented. The originality of the method lies in an adequate use of asymptotic expansions of Wronskians of algebraic solutions of the Schroedinger equation. The procedure is applied to three familiar examples of spiked oscillators

Coulomb plus power-law potentials in quantum mechanics

We study the discrete spectrum of the Hamiltonian H = -Delta + V(r) for the Coulomb plus power-law potential V(r)=-1/r+ beta sgn(q)r^q, where beta > 0, q > -2 and q \ne 0. We show by envelope theory that the discrete eigenvalues E_{n\ell} of H may be approximated by the semiclassical expression E_{n\ell}(q) \approx min_{r>0}\{1/r^2-1/(mu r)+ sgn(q) beta(nu r)^q}. Values of mu and nu are prescribed which yield upper and lower bounds. Accurate upper bounds are also obtained by use of a trial function of the form, psi(r)= r^{\ell+1}e^{-(xr)^{q}}. We give detailed results for V(r) = -1/r + beta r^q, q = 0.5, 1, 2 for n=1, \ell=0,1,2, along with comparison eigenvalues found by direct numerical methods.Comment: 11 pages, 3 figure

Semiclassical energy formulas for power-law and log potentials in quantum mechanics

We study a single particle which obeys non-relativistic quantum mechanics in R^N and has Hamiltonian H = -Delta + V(r), where V(r) = sgn(q)r^q. If N \geq 2, then q > -2, and if N = 1, then q > -1. The discrete eigenvalues E_{n\ell} may be represented exactly by the semiclassical expression E_{n\ell}(q) = min_{r>0}\{P_{n\ell}(q)^2/r^2+ V(r)}. The case q = 0 corresponds to V(r) = ln(r). By writing one power as a smooth transformation of another, and using envelope theory, it has earlier been proved that the P_{n\ell}(q) functions are monotone increasing. Recent refinements to the comparison theorem of QM in which comparison potentials can cross over, allow us to prove for n = 1 that Q(q)=Z(q)P(q) is monotone increasing, even though the factor Z(q)=(1+q/N)^{1/q} is monotone decreasing. Thus P(q) cannot increase too slowly. This result yields some sharper estimates for power-potential eigenvlaues at the bottom of each angular-momentum subspace.Comment: 20 pages, 5 figure