14,724 research outputs found
Some monetary facts
This article describes three long-run monetary facts derived by examining data for 110 countries over a 30-year period, using three definitions of a country's money supply and two subsamples of countries: (1) Growth rates of the money supply and the general price level are highly correlated for all three money definitions, for the full sample of countries, and for both subsamples. (2) The growth rates of money and real output are not correlated, except for a subsample of countries in the Organisation for Economic Co-operation and Development, where these growth rates are positively correlated. (3) The rate of inflation and the growth rate of real output are essentially uncorrelated. ; Reprinted in Quarterly Review, Fall 2001 (v. 25, no. 4)Money supply ; Monetary theory
NASA research activities in aeropropulsion
NASA is responsible for advancing technologies related to air transportation. A sampling of the work at NASA's Lewis Research Center aimed at improved aircraft propulsion systems is described. Particularly stressed are efforts related to reduced noise and fuel consumption of subsonic transports. Generic work in specific disciplines are reviewed including computational analysis, materials, structures, controls, diagnostics, alternative fuels, and high-speed propellers. Prospects for variable cycle engines are also discussed
One-dimensional p-wave superconductor toy-model for Majorana fermions in multiband semiconductor nanowires
Majorana fermions are particles identical to their antiparticles proposed
theoretically in 1937 by Ettore Majorana as real solutions of the Dirac
equation. Alexei Kitaev suggested that Majorana particles should emerge in
condensed matter systems as zero mode excitations in one-dimensional p-wave
superconductors, with possible applications in quantum computation due to their
non-abelian statistics. The search for Majorana zero modes in condensed matter
systems led to one of the first realistic models based in a semiconductor
nanowire with high spin-orbit coupling, induced superconducting s-wave pairing
and Zeeman splitting. Soon, it was realized that size-quantization effects
should generate subbands in these systems that could even allow the emergence
of more than one Majorana mode at each edge, resulting in a zero bias peak on
the differential conductance with a different shape from the predicted by
simplified theoretical models. In this work, we provide a connection between a
finite-size nanowire with two occupied subbands and a 2-band Kitaev chain and
discuss the advantage of an one-dimensional model to understand the
phenomenology of the system, including the presence of a hidden chiral symmetry
and its similarity with a spinfull Kitaev chain under a magnetic field.Comment: 4 pages, 2 figures. IEEE Transactions on Applied Superconductivity
accepted versio
Territoriality and Spatial Structure in the Green Anole, Anolis carolinensis
Anolis carolinensis has been a model organism for ecology and evolutionary biology since the seventies, yet there are still understudied aspects of their ecology. A five-year study has provided microsatellite genotypes to be used in building a pedigree and assess relatedness, enabling us to evaluate the spatial distribution of an urban population of A. carolinensis. Results indicate no correlation between a male’s size and the distance others keep from it; however, males belonging in the heavyweight morph are dictating the spatial distribution in this population. In addition, juvenile dispersal of male offspring and partial philopatry of female offspring are key in this dynamic, where a single heavyweight male will actively defend a small area that contains multiple females, some of which are be daughters, and multiple unrelated males, most likely sneaker males
Paleoenvironmental Analysis and Test of Stratigraphic Cyclicity in the Nolichucky Shale and Maynardville Limestone (Upper Cambrian) in Central East Tennessee
The Upper Cambrian Nolichucky Shale and Maynardville Limestone (upper Conasauga Group) crop out along a succession of southeastward dipping imbricate thrust sheets, which trend northeast-southwest in the Valley and Ridge of eastern Tennessee. In the vicinity of Oak Ridge and Knoxville, Nolichucky and Maynardville outcrop and drill core have been examined at six localities. The Nolichucky contains an abundance of thick shale and thinly bedded shale and limestone, whereas the Maynardville is composed of very thick-bedded carbonate, predominantly limestone. In central east Tennessee fourteen major lithofacies are identified in the upper Conasauga Group. The Nolichucky/Maynardville sequence is subdivided into three parts representing: (1) a slightly deeper intracratonic basin (30-50 m water depth; lower Nolichucky, (2) a shallow intracratonic basin (5-30 m deep; upper Nolichucky), and (3) a peritidal platform (0-5 m deep; Maynardville).
The Nolichucky Shale was deposited in a storm-dominated paleoÂenvironmental setting, whereas the Maynardville Limestone is similar to other ancient tidally-influenced deposits. In the Nolichucky, the majority of carbonate production occurred in and around shoals and within cyanobacterial mats. Storms were effective in moving carbonate sediment off the shoals and mats into adjacent shale-dominated subtidal areas. The Maynardville represents small tidal flats that accreted vertically and migrated laterally. Sediment was produced in open-water subtidal areas, which were adjacent to tidal flats, and tides, storms, and fairweather waves transported sediment to nearby low-relief intertidal banks and supratidal islands. The distribution of facies along the Nolichucky/Maynardville bathymetric profile was much more irregular (mosaic-like) than predicted by the depositional model of earlier workers.
An integrated approach of overlying substitutability analysis, embedded Markov chain analysis, and modified autoassociation analysis to verify statistically the occurrence of cycles in stratigraphic sequences is applied to the upper Conasauga Group of central east Tennessee. Stratigraphic sections within the Nolichucky Shale and in the Maynardville Limestone show weakly developed cyclicity, which is probably a result of the storm- and tide-dominated paleoenvironmental setting. Local processes were more important in controlling lithologic repetition than were larger-scale processes (e.g., geoidal, tectonic, or glacioeustatic). Large-scale processes have been documented in modern and other ancient settings, but their record may be masked in many sequences by local events
On Program Synthesis in Intelligent Calculators Through Current Autoprogramming Techniques
Recent technology has placed powerful computing devices within the grasp of the average layman. The calculator is the most widely utilized such device end its power now compares to that of the first computers. While the users of these calculators are familiar with strict sequential operations, few are familiar with programming techniques. Much work has been done on program and machine inference from example input and output traces. An evaluation and assimilation of current machine synthesis studies and auto programming techniques has been described. An intelligent calculator capable of automatically constructing or inferring suitable programs from example computations executed by the user, keeping the additional required knowledge of the user at a minimum, has been proposed
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