Calculation of the optical conductivity for the Anderson impurity model using the slave boson technique

The optical conductivity of the Anderson impurity mode l has been calculated by emp l oying the slave boson technique and an expansion in powers of l i N, where N is the d egeneracy o f the f electron level . This method has been used to find the effective mass of the conduction electrons for temperatures above and below the Kondo tempera ture. For low temperatures, the mass enhancement is f ound to be large while a t high t emperatures, the mass enhancement is sma ll. The conductivity i s f ound to be Drude like with frequency dependent effective mass and scattering time for low independent effective mass and temperatures and scattering time f requency for high t emperatures. The behavior of both the effective mass and the conductivity is in qualitative agreement with experimental r esul t s .

Indenture between Gilbert Anderson, Phoebe Anderson and John Picard

Indenture of bargain and sale between Gilbert Anderson the younger of the Township of Niagara and Phoebe Anderson (his wife) and John Picard of the Township of Niagara. The instrument no. is 6268. April 14, 1855.

Letter to Joseph A. Woodruff from Mr. Anderson

Letter to Joseph A. Woodruff from Mr. Anderson. He asks if Mr. Woodruff was able to bear some pressure on the judge to settle the old claim between Milroy and Price. This is accompanied by an envelope, Aug. 24, 1865.

Receipt from Adam, Meldrum and Anderson Dry Goods and Carpets

Receipt from Adam, Meldrum and Anderson Dry Goods and Carpets, Buffalo, New York for curtains, materials and hooks, Sept. 6, 1886.

Receipt from Adam, Meldrum and Anderson, Buffalo, New York

Receipt from Adam, Meldrum and Anderson, Buffalo, New York for sateen, May 17, 1887.

Chaotic, memory, and cooling rate effects in spin glasses: Evaluation of the Edwards-Anderson model

We investigate chaotic, memory, and cooling rate effects in the three-dimensional Edwards-Anderson model by doing thermoremanent (TRM) and ac susceptibility numerical experiments and making a detailed comparison with laboratory experiments on spin glasses. In contrast to the experiments, the Edwards-Anderson model does not show any trace of reinitialization processes in temperature change experiments (TRM or ac). A detailed comparison with ac relaxation experiments in the presence of dc magnetic field or coupling distribution perturbations reveals that the absence of chaotic effects in the Edwards-Anderson model is a consequence of the presence of strong cooling rate effects. We discuss possible solutions to this discrepancy, in particular the smallness of the time scales reached in numerical experiments, but we also question the validity of the Edwards-Anderson model to reproduce the experimental results.

Mining Events from Multimedia streams, Jon Hare

peaker(s): Jon Hare Organiser: Time: 25/06/2014 11:00-11:50 Location: B32/3077 Abstract The aggregation of items from social media streams, such as Flickr photos and Twitter tweets, into meaningful groups can help users contextualise and effectively consume the torrents of information on the social web. This task is challenging due to the scale of the streams and the inherently multimodal nature of the information being contextualised. In this talk I'll describe some of our recent work on trend and event detection in multimedia data streams. We focus on scalable streaming algorithms that can be applied to multimedia data streams from the web and the social web. The talk will cover two particular aspects of our work: mining Twitter for trending images by detecting near duplicates; and detecting social events in multimedia data with streaming clustering algorithms. I'll will describe in detail our techniques, and explore open questions and areas of potential future work, in both these tasks.

Nova et Vetera: Edición 12, Abril 7 - 13 de 2014

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Intervención del Estado colombiano en el sector solidario

El propósito de este libro es explicar los fundamentos históricos, jurídicos, políticos y económicos que permiten al Estado colombiano incidir en el sector solidario, con base en los principios de igualdad Y libertad y en el marco del Estado social de derecho, que exige su activismo a través de algunos modelos e instrumentos de intervención económica. Para ello, se ha adoptado una taxonomía emergente que aglutina sus componentes en dos subsectores, a partir de una identidad y una racionalidad propias que los diferencia de los demás empresas capitalistas, estos son: el de las organizaciones de economía solidaria (OES) y el de las organizaciones solidarias de desarrollo (OSD). Esta visión holística posibilita aportar ciertos elementos críticos que cuestionan el comportamiento de los actores públicos, cuyo papel está definido por mandato constitucional, y el de las organizaciones, que al proceder de manera disfuncional obstaculizan el progreso económico y social del país.

Fast and accurate SCFT calculations for periodic block-copolymer morphologies using the spectral method with Anderson mixing

We study the numerical efficiency of solving the self-consistent field theory (SCFT) for periodic block-copolymer morphologies by combining the spectral method with Anderson mixing. Using AB diblock-copolymer melts as an example, we demonstrate that this approach can be orders of magnitude faster than competing methods, permitting precise calculations with relatively little computational cost. Moreover, our results raise significant doubts that the gyroid (G) phase extends to infinite $\chi N$. With the increased precision, we are also able to resolve subtle free-energy differences, allowing us to investigate the layer stacking in the perforated-lamellar (PL) phase and the lattice arrangement of the close-packed spherical (S$_{cp}$) phase. Furthermore, our study sheds light on the existence of the newly discovered Fddd (O$^{70}$) morphology, showing that conformational asymmetry has a significant effect on its stability.

Efficiency of pseudo-spectral algorithms with Anderson mixing for the SCFT of periodic block-copolymer phases

This study examines the numerical accuracy, computational cost, and memory requirements of self-consistent field theory (SCFT) calculations when the diffusion equations are solved with various pseudo-spectral methods and the mean field equations are iterated with Anderson mixing. The different methods are tested on the triply-periodic gyroid and spherical phases of a diblock-copolymer melt over a range of intermediate segregations. Anderson mixing is found to be somewhat less effective than when combined with the full-spectral method, but it nevertheless functions admirably well provided that a large number of histories is used. Of the different pseudo-spectral algorithms, the 4th-order one of Ranjan, Qin and Morse performs best, although not quite as efficiently as the full-spectral method.