11,817 research outputs found

    Encode/Decode facility for FORTRAN 4

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    An ENCODE and DECODE facility, a subroutine added to a FORTRAN 4 library, allows alphanumeric data to be transfered to or from an area in memory rather than to or from external input/output devices. A buffer storage array allows the operations on the data prior to writing

    Punch-magnet delay eliminated by modification of circuit

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    Reduction of retardation by diode-resistor networks of the current-decay time of a punch magnet by connection of a Zener diode in series with the damping network increases the reliability of data on paper tape

    Old Licenses and New Uses: Motion Picture and Television Rights

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    There are many possible ways to perform the attitude control of a quadcopter and, recently, the subject of event-triggered control has become relevant in the scientic community. This thesis deals with the analysis and implementation of a saturating attitude controller for a quadcopter system, together with the derivation of an event-triggering rule to work with it. Two distinct rules are presented, one that ensures the stability of the closed loop system, the other, a linearised version that does not. The way those were derived consists in the use of a Lyapunov based approach. The stability of the system when under these rules was veried experimentally

    Rechargeable battery which combats shape change of the zinc anode

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    A rechargeable cell or battery is provided in which shape change of the zinc anode is combatted by profiling the ionic conductivity of the paths between the electrodes. The ion flow is greatest at the edges of the electrodes and least at the centers, thereby reducing migration of the zinc ions from edges to the center of the anode. A number of embodiments are disclosed in which the strength and/or amount of electrolyte, and/or the number and/or size of the paths provided by the separator between the electrodes, are varied to provide the desired ionic conductivity profile

    Fuse and switch functions combined within a single housing

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    Fuswitch provides both switch and fuse functions within a single housing. A mercury capillary is used to alternately vaporize and condense the mercury within a reservoir. The housing is impervious to mercury and the fuse portion of the device operates on the principle of the self-healing mercury fuse

    Prediction of Functional Sites in SCOP Domains using Dynamics Perturbation Analysis

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    Dynamics perturbation analysis (DPA) finds regions in a protein structure where proteins are "ticklish", i.e., where interactions cause a large change in protein dynamics. Previously, such regions were shown to predict the location of native binding sites in a docking test set, but the more general applicability of DPA to the prediction of functional sites in proteins was not shown. Here we describe the results of applying an accelerated algorithm, called Fast DPA, to predict functional sites in over 50,000 SCOP domains

    An analysis of the vertical structure equation for arbitrary thermal profiles

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    The vertical structure equation is a singular Sturm-Liouville problem whose eigenfunctions describe the vertical dependence of the normal modes of the primitive equations linearized about a given thermal profile. The eigenvalues give the equivalent depths of the modes. The spectrum of the vertical structure equation and the appropriateness of various upper boundary conditions, both for arbitrary thermal profiles were studied. The results depend critically upon whether or not the thermal profile is such that the basic state atmosphere is bounded. In the case of a bounded atmosphere it is shown that the spectrum is always totally discrete, regardless of details of the thermal profile. For the barotropic equivalent depth, which corresponds to the lowest eigen value, upper and lower bounds which depend only on the surface temperature and the atmosphere height were obtained. All eigenfunctions are bounded, but always have unbounded first derivatives. It was proved that the commonly invoked upper boundary condition that vertical velocity must vanish as pressure tends to zero, as well as a number of alternative conditions, is well posed. It was concluded that the vertical structure equation always has a totally discrete spectrum under the assumptions implicit in the primitive equations

    Red Sequence Cluster Finding in the Millennium Simulation

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    We investigate halo mass selection properties of red-sequence cluster finders using galaxy populations of the Millennium Simulation (MS). A clear red sequence exists for MS galaxies in massive halos at redshifts z < 1, and we use this knowledge to inform a cluster-finding algorithm applied to 500 Mpc/h projections of the simulated volume. At low redshift (z=0.4), we find that 90% of the clusters found have galaxy membership dominated by a single, real-space halo, and that 10% are blended systems for which no single halo contributes a majority of a cluster's membership. At z=1, the fraction of blends increases to 22%, as weaker redshift evolution in observed color extends the comoving length probed by a fixed range of color. Other factors contributing to the increased blending at high-z include broadening of the red sequence and confusion from a larger number of intermediate mass halos hosting bright red galaxies of magnitude similar to those in higher mass halos. Our method produces catalogs of cluster candidates whose halo mass selection function, p(M|\Ngal,z), is characterized by a bimodal log-normal model with a dominant component that reproduces well the real-space distribution, and a redshift-dependent tail that is broader and displaced by a factor ~2 lower in mass. We discuss implications for X-ray properties of optically selected clusters and offer ideas for improving both mock catalogs and cluster-finding in future surveys.Comment: final version to appear in MNRAS. Appendix added on purity and completeness, small shift in red sequence due to correcting an error in finding i

    Progress in electrochemical storage for battery systems

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    Efforts to improve electrochemical systems for space use relate to: (1) improvement of conventional systems; (2) development of fuel cells to practical power systems; and (3) a search for new systems that provide gains in energy density but offer comparable life and performance as conventional systems. Improvements in sealed conventional systems resulted in the areas of materials, charge control methods, cell operations and battery control, and specific process controls required during cell manufacture. Fuel-cell systems have been developed for spacecraft but the use of these power plants is limited. For present and planned flights, nickel-cadmium, silver-zinc, and silver-cadmium systems will be used. Improvements in nickel-cadmium batteries have been applied in medical and commercial areas
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