2,037 research outputs found

    Isolation and component structure in spaces of composition operators

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    We establish a condition that guarantees isolation in the space of composition operators acting between H p (B N ) and H q (B N ), for 0 \u3c p ≤ ∞, 0 \u3c q \u3c ∞, and N ≥ 1. This result will allow us, in certain cases where 0 \u3c q \u3c p ≤ ∞, completely to characterize the component structure of this space of operators

    A densitometric analysis of commercial 35mm films

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    IIaO films have been subjected to various sensitometric tests. The have included thermal and aging effects and reciprocity failure studies. In order to compare the special IIaO film with popular brands of 35 mm films and their possible use in astrophotography, Agfa, Fuji and Kodak print and slide formats, as well as black and white and color formats, were subjected to sensitometric, as well as densitometric analysis. A scanning electron microscope was used to analyze grain structure size, and shape as a function of both speed and brand. Preliminary analysis of the grain structure using an ISI-SS40 scanning electron microscope indicates that the grain sizes for darker densities are much larger than the grain size for lighter densities. Researchers analyze the scanning electron microscope findings of the various grains versus densities as well as enhancement of the grains, using the IP-8500 Digital Image Processor

    Eigenvalue Spacing Distribution for the Ensemble of Real Symmetric Toeplitz Matrices

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    Consider the ensemble of Real Symmetric Toeplitz Matrices, each entry iidrv from a fixed probability distribution p of mean 0, variance 1, and finite higher moments. The limiting spectral measure (the density of normalized eigenvalues) converges weakly to a new universal distribution with unbounded support, independent of p. This distribution's moments are almost those of the Gaussian's; the deficit may be interpreted in terms of Diophantine obstructions. With a little more work, we obtain almost sure convergence. An investigation of spacings between adjacent normalized eigenvalues looks Poissonian, and not GOE.Comment: 24 pages, 3 figure

    Moessbauer spectroscopy and scanning electron microscopy of the Murchison meteorite

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    Meteorites provide a wealth of information about the solar system's formation, since they have similar building blocks as the Earth's crust but have been virtually unaltered since their formation. Some stony meteorites contain minerals and silicate inclusions, called chondrules, in the matrix. Utilizing Moessbauer spectroscopy, we identified minerals in the Murchison meteorite, a carbonaceous chondritic meteorite, by the gamma ray resonance lines observed. Absorption patterns of the spectra were found due to the minerals olivine and phyllosilicate. We used a scanning electron microscope to describe the structure of the chondrules in the Murchison meteorite. The chondrules were found to be deformed due to weathering of the meteorite. Diameters varied in size from 0.2 to 0.5 mm. Further enhancement of the microscopic imagery using a digital image processor was used to describe the physical characteristics of the inclusions

    Deliberative democracy and inequality: Two cheers for enclave deliberation among the disempowered

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    Deliberative democracy grounds its legitimacy largely in the ability of speakers to participate on equal terms. Yet theorists and practitioners have struggled with how to establish deliberative equality in the face of stark differences of power in liberal democracies. Designers of innovative civic forums for deliberation often aim to neutralize inequities among participants through proportional inclusion of disempowered speakers and discourses. In contrast, others argue that democratic equality is best achieved when disempowered groups deliberate in their own enclaves (interest groups, parties, and movements) before entering the broader public sphere. Borrowing from each perspective, the authors argue that there are strong reasons to incorporate enclave deliberation among the disempowered within civic forums. They support this claim by presenting case study evidence showing that participants in such forums can gain some of the same benefits of deliberation found in more heterogeneous groups (e.g., political knowledge, efficacy and trust), can consider a diversity of viewpoints rather than falling into groupthink and polarization, and can persuade external stakeholders of the legitimacy of the group’s deliberations
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