15,933 research outputs found

    Reassessing the Link between Voter Heterogeneity and Political Accountability: A Latent Class Regression Model of Economic Voting

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    While recent research has underscored the conditioning effect of individual characteristics on economic voting behavior, most empirical studies have failed to explicitly incorporate observed heterogeneity into statistical analyses linking citizens' economic evaluations to electoral choices. In order to overcome these drawbacks, we propose a latent class regression model to jointly analyze the determinants and influence of economic voting in Presidential and Congressional elections. Our modeling approach allows us to better describe the effects of individual covariates on economic voting and to test hypotheses on the existence of heterogeneous types of voters, providing an empirical basis for assessing the relative validity of alternative explanations proposed in the literature. Using survey data from the 2004 U.S. Presidential, Senate and House elections, we and that voters with college education and those more interested in political campaigns based their vote on factors other than their economic perceptions. In contrast, less educated and interested respondents assigned considerable weight to economic assessments, with sociotropic jugdgments strongly in uencing their vote in the Presidential election and personal financial considerations affecting their vote in House elections. We conclude that the main distinction in the 2004 election was not between `sociotropic' and `pocketbook' voters, but rather between `economic' and `non-economic' voters

    Quasi-Langmuir-Blodgett Thin Film Deposition of Carbon Nanotubes

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    The handling and manipulation of carbon nanotubes continues to be a challenge to those interested in the application potential of these promising materials. To this end, we have developed a method to deposit pure nanotube films over large flat areas on substrates of arbitrary composition. The method bears some resemblance to the Langmuir-Blodgett deposition method used to lay down thin organic layers. We show that this redeposition technique causes no major changes in the films' microstructure and that they retain the electronic properties of as-deposited film laid down on an alumina membrane.Comment: 3 pages, 3 figures, submitted Journal of Applied Physic

    Figure of merit studies of beam power concepts for advanced space exploration

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    Surface to surface, millimeter wavelength beam power systems for power transmission on the lunar base were investigated. Qualitative/quantitative analyses and technology assessment of 35, 110 and 140 GHz beam power systems were conducted. System characteristics including mass, stowage volume, cost and efficiency as a function of range and power level were calculated. A simple figure of merit analysis indicates that the 35 GHz system would be the preferred choice for lunar base applications, followed closely by the 110 GHz system. System parameters of a 35 GHz beam power system appropriate for power transmission on a recent lunar base concept studied by NASA-Johnson and the necessary deployment sequence are suggested

    The ballistic acceleration of a supercurrent in a superconductor

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    One of the most primitive but elusive current-voltage (I-V) responses of a superconductor is when its supercurrent grows steadily after a voltage is first applied. The present work employed a measurement system that could simultaneously track and correlate I(t) and V(t) with sub-nanosecond timing accuracy, resulting in the first clear time-domain measurement of this transient phase where the quantum system displays a Newtonian like response. The technique opens doors for the controlled investigation of other time dependent transport phenomena in condensed-matter systems.Comment: 4 pages, 3 figure

    Scaling laws for precision in quantum interferometry and bifurcation landscape of optimal state

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    Phase precision in optimal 2-channel quantum interferometry is studied in the limit of large photon number N≫1N\gg 1, for losses occurring in either one or both channels. For losses in one channel an optimal state undergoes an intriguing sequence of local bifurcations as the losses or the number of photons increase. We further show that fixing the loss paramater determines a scale for quantum metrology -- a crossover value of the photon number NcN_c beyond which the supra-classical precision is progressively lost. For large losses the optimal state also has a different structure from those considered previously.Comment: 4 pages, 3 figures, v3 is modified in response to referee comment

    The Solow model in discrete time and decreasing population growth rate

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    This paper reformulates the neoclassical Solow-Swan model of economic growth in discrete time by introducing a generic population growth law that verifies the following properties: 1) population is strictly increasing and bounded 2) the rate of growth of population is decreasing to zero as time tends to infinity. We show that in the long run the capital per worker of the model converges to the non-trivial steady state of the Solow Swan model with zero labor growth rate. In addition we prove that the solutions of the model are asymptotically stable.Solow model
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