14,994 research outputs found
A clarification of the Goodwin model of the growth cycle
We show that there is a difficulty in the original Goodwin model which isalso found in some more recent applications. In it both the labour share and theproportion employed can exceed unity, properties which are untenable. However, weshow that the underlying dynamic structure of the model can be reformulated toensure that these variables cannot exceed unity. An illustrative example extends theoriginal model, and we argue it is both plausible and satisfies the necessary unit boxrestrictions. We show that there is a difficulty in the original Goodwin model which isalso found in some more recent applications. In it both the labour share and theproportion employed can exceed unity, properties which are untenable. However, weshow that the underlying dynamic structure of the model can be reformulated toensure that these variables cannot exceed unity. An illustrative example extends theoriginal model, and we argue it is both plausible and satisfies the necessary unit boxrestrictions
Microscale application of column theory for high resolution force and displacement sensing
We present the design, fabrication and experimental validation of a novel
device that exploits the amplification of displacement and attenuation of
structural stiffness in the post-buckling deformation of slender columns to
obtain pico-Newton force and nanometer displacement resolution even under an
optical microscope. The extremely small size, purely mechanical sensing scheme
and vacuum compatibility of the instrument makes it compatible with existing
visualization tools of nanotechnology. The instrument has a wide variety of
potential applications ranging from electro-mechanical characterization of one
dimensional solids to single biological cells
The Effect of Simultaneous Intensification on the Detective Quantum Efficiency
The effect of simultaneous intensification on the detective quantum efficiency of Kodak high definition aerial film type 3414 is investigated. The detective quantum efficiency or DQE varies from .00086 % to .115 % for the unintensified exposure over a log exposure range of 0.9, with the peak at .1223 %. This exposure has a base+fog density of 0.06. Different degrees of simultaneous intensification result in varying values of DQE. The exposure with simultaneous intensification which produced a base+fog of 0.24 gave the maximum sensitometric speed incease by a factor of 1.38 f/stops or 158 %. This exposure varies in DQE from .012 % to .06 % over the same exposure range of 0.9 log unit with the peak at .06 %. The ratio of maximum DQE to minimum DQE for the unintensified exposure is 226:1; compared to the ratio 5:1 for the intensified exposure. This shows the variation in detectivity of the two exposures over a given range of exposure. It can be clearly seen that the intensified exposure maintains an overall higher and constant level of DQE even though the maximum DQE is not as high as the unintensified exposure
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Shock Therapy and After: Prospects for Russian Reform
"In the third year of its transition to a functioning market
economy free from high inflation, Russia began its toughest phase
in 1994 under the Chernomyrdin government. The approval by the
International Monetary Fund (IMF) in March of the second tranche of
$1.5 billion signaled support for the economic program of the new
government. The subsequent adoption by the Duma (lower house of the
parliament) of the government's budget and the signing of the civil
accord by several parliamentary factions and industry groups marked
a step, albeit fragile, in the direction of national consensus.
The Goddard program of gamma ray transient astronomy
Gamma ray burst studies are reviewed. The past results, present status and future expectations are outlined regarding endeavors using experiments on balloons, IMP-6 and -7, OGO-3, ISEE-1 and -3, Helios-2, Solar Maximum Mission, the Einstein Observatory, Solar Polar and the Gamma Ray Observatory, and with the interplanetary gamma ray burst networks, to which some of these spacecraft sensors contribute. Additional emphasis is given to the recent discovery of a new type of gamma ray transient, detected on 1979 March 5
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