11,062 research outputs found

    The use of the Winograd matrix multiplication algorithm in digital multispectral processing

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    The Winograd procedure for matrix multiplication provides a method whereby general matrix products may be computed more efficiently than the normal method. The algorithm and the time savings that can be effected are described. A FORTRAN program is provided which performs a general matrix multiply according to this algorithm. A variation of this procedure that may be used to calculate Gaussian probability density functions is also described. It is shown how a time savings can be effected in this calculation. The extension of this method to other similar calculations should yield similar savings

    Self-dual Yang-Mills fields in pseudoeuclidean spaces

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    The self-duality Yang-Mills equations in pseudoeuclidean spaces of dimensions d≀8d\leq 8 are investigated. New classes of solutions of the equations are found. Extended solutions to the D=10, N=1 supergravity and super Yang-Mills equations are constructed from these solutions.Comment: 9 pages, LaTeX, no figure

    A Tale of Three Cities: Crime and Displacement after Hurricane Katrina

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    When Hurricane Katrina struck New Orleans in August 2005, it greatly disrupted both the physical and social structures of that community. One consequence of the hurricane was the displacement of large numbers of New Orleans residents to other cities, including Houston, San Antonio, and Phoenix. There has been media speculation that such a grand-scale population displacement led to increased crime in communities that were recipient of large numbers of displaced New Orleans residents. This study was a case study of three cities with somewhat different experiences with Katrina\u27s diaspora. Time series analysis was used to examine the pre- and post-Katrina trends in six Part I offenses (murder, robbery, aggravated assault, rape, burglary, and auto theft) to assess any impact of such large-scale population shifts on crime in host communities. Contrary to much popular speculation, only modest effects were found on crime. Social disorganization theory was used to frame both the analysis and the interpretation of these result

    Effective Gap Equation for the Inhomogeneous LOFF Superconductive Phase

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    We present an approximate gap equation for different crystalline structures of the LOFF phase of high density QCD at T=0. This equation is derived by using an effective condensate term obtained by averaging the inhomogeneous condensate over distances of the order of the crystal lattice size. The approximation is expected to work better far off any second order phase transition. As a function of the difference of the chemical potentials of the up and down quarks, ÎŽÎŒ\delta\mu, we get that the octahedron is energetically favored from ÎŽÎŒ=Δ0/2\delta\mu=\Delta_0/\sqrt 2 to 0.95Δ00.95\Delta_0, where Δ0\Delta_0 is the gap for the homogeneous phase, while in the range 0.95Δ0−1.32Δ00.95\Delta_0-1.32\Delta_0 the face centered cube prevails. At ÎŽÎŒ=1.32Δ0\delta\mu=1.32\Delta_0 a first order phase transition to the normal phase occurs.Comment: 11 pages, 5 figure

    Extending Native Winter Pasture Use with Spring Grazing Practices

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    Improving profitability will help sustain the economic viability of ranch operations. Feed costs typically represent well over half of annual cow-calf production costs. Two things, 1) grazing strategies aimed at increasing the proportion of feed supplied through grazing and 2) decreasing reliance on high-cost harvested forages, have the potential to improve profit

    Alternativity and reciprocity in the Cayley-Dickson algebra

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    We calculate the eigenvalue \rho of the multiplication mapping R on the Cayley-Dickson algebra A_n. If the element in A_n is composed of a pair of alternative elements in A_{n-1}, half the eigenvectors of R in A_n are still eigenvectors in the subspace which is isomorphic to A_{n-1}. The invariant under the reciprocal transformation A_n \times A_{n} \ni (x,y) -> (-y,x) plays a fundamental role in simplifying the functional form of \rho. If some physical field can be identified with the eigenspace of R, with an injective map from the field to a scalar quantity (such as a mass) m, then there is a one-to-one map \pi: m \mapsto \rho. As an example, the electro-weak gauge field can be regarded as the eigenspace of R, where \pi implies that the W-boson mass is less than the Z-boson mass, as in the standard model.Comment: To be published in J. Phys. A: Mathematical and Genera

    The Ginzburg-Landau Free Energy Functional of Color Superconductivity at Weak Coupling

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    We derive the Ginzburg-Landau free energy functional of color superconductivity in terms of the thermal diagrams of QCD in its perturbative region. The zero mode of the quadratic term coefficient yields the same transition temperature, including the pre-exponential factor, as the one obtained previously from the Fredholm determinant of the two quark scattering amplitude. All coefficients of the free energy can be made identical to those of a BCS model by setting the Fermi velocity of the latter equal to the speed of light. We also calculate the induced symmetric color condensate near TcT_c and find that it scales as the cubic power of the dominant antisymmetric color component. We show that in the presence of an inhomogeneity and a nonzero gauge potential, while the color-flavor locked condensate dominates in the bulk, the unlocked condensate, the octet, emerges as a result of a simultaneous color-flavor rotation in the core region of a vortex filament or at the junction of super and normal phases.Comment: 32 pages, Plain Tex, 3 figure
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