853 research outputs found

    Half-Metallic Ferromagnetism in the Heusler Compound Co2_2FeSi revealed by Resistivity, Magnetoresistance, and Anomalous Hall Effect measurements

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    We present electrical transport data for single-crystalline Co2_2FeSi which provide clear-cut evidence that this Heusler compound is truly a half-metallic ferromagnet, i.e. it possesses perfect spin-polarization. More specifically, the temperature dependence of ρ\rho is governed by electron scattering off magnons which are thermally excited over a sizeable gap Δ100K\Delta\approx 100 K (9meV\sim 9 meV) separating the electronic majority states at the Fermi level from the unoccupied minority states. As a consequence, electron-magnon scattering is only relevant at TΔT\gtrsim\Delta but freezes out at lower temperatures, i.e., the spin-polarization of the electrons at the Fermi level remains practically perfect for TΔT\lesssim\Delta. The gapped magnon population has a decisive influence on the magnetoresistance and the anomalous Hall effect (AHE): i) The magnetoresistance changes its sign at T100KT\sim 100 K, ii) the anomalous Hall coefficient is strongly temperature dependent at T100KT\gtrsim 100 K and compatible with Berry phase related and/or side-jump electronic deflection, whereas it is practically temperature-independent at lower temperatures

    Reservoir Computing Approach to Robust Computation using Unreliable Nanoscale Networks

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    As we approach the physical limits of CMOS technology, advances in materials science and nanotechnology are making available a variety of unconventional computing substrates that can potentially replace top-down-designed silicon-based computing devices. Inherent stochasticity in the fabrication process and nanometer scale of these substrates inevitably lead to design variations, defects, faults, and noise in the resulting devices. A key challenge is how to harness such devices to perform robust computation. We propose reservoir computing as a solution. In reservoir computing, computation takes place by translating the dynamics of an excited medium, called a reservoir, into a desired output. This approach eliminates the need for external control and redundancy, and the programming is done using a closed-form regression problem on the output, which also allows concurrent programming using a single device. Using a theoretical model, we show that both regular and irregular reservoirs are intrinsically robust to structural noise as they perform computation

    A Drosophila screen identifies NKCC1 as a modifier of NGLY1 deficiency

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    N-Glycanase 1 (NGLY1) is a cytoplasmic deglycosylating enzyme. Loss-of-function mutations in the NGLY1 gene cause NGLY1 deficiency, which is characterized by developmental delay, seizures, and a lack of sweat and tears. To model the phenotypic variability observed among patients, we crossed a Drosophila model of NGLY1 deficiency onto a panel of genetically diverse strains. The resulting progeny showed a phenotypic spectrum from 0 to 100% lethality. Association analysis on the lethality phenotype, as well as an evolutionary rate covariation analysis, generated lists of modifying genes, providing insight into NGLY1 function and disease. The top association hit was Ncc69 (human NKCC1/2), a conserved ion transporter. Analyses in NGLY1-/- mouse cells demonstrated that NKCC1 has an altered average molecular weight and reduced function. The misregulation of this ion transporter may explain the observed defects in secretory epithelium function in NGLY1 deficiency patients

    Information processing using a single dynamical node as complex system

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    Novel methods for information processing are highly desired in our information-driven society. Inspired by the brain's ability to process information, the recently introduced paradigm known as 'reservoir computing' shows that complex networks can efficiently perform computation. Here we introduce a novel architecture that reduces the usually required large number of elements to a single nonlinear node with delayed feedback. Through an electronic implementation, we experimentally and numerically demonstrate excellent performance in a speech recognition benchmark. Complementary numerical studies also show excellent performance for a time series prediction benchmark. These results prove that delay-dynamical systems, even in their simplest manifestation, can perform efficient information processing. This finding paves the way to feasible and resource-efficient technological implementations of reservoir computing

    Принципи та цілі логістичного обслуговування в контексті підвищення рівня конкурентоспроможності підприємства

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    In this article, we examine the digitalised emotional campaigning of one of Australia’s peak animal welfare body, Animals Australia, focusing on their most effective digital strategies associated with their campaigns against factory farming. Our broader interest lies with sounding out the affective affordances of the technologies informing such activist work; technologies of affect in a very significant sense. This discussion comprises three parts. First, we unpack the context for the problematic faced by animal and environmental activisms: neoliberalism, showing how neoliberal assumptions constrain such activisms to emotional appeals and denounce them for such strategising. Second, we sound out some of the affordances of digital media technologies for affectively oriented activisms; and finally, we delve into some of Animals Australia’s digital campaigning with regard to issues of factory farming in order to show the efficacy of such affectively oriented mediated strategising for the forming of new relations with factory farm. © 2017, © The Author(s) 2017

    Social Cohesion, Structural Holes, and a Tale of Two Measures

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    EMBARGOED - author can archive pre-print or post-print on any open access repository after 12 months from publication. Publication date is May 2013 so embargoed until May 2014.This is an author’s accepted manuscript (deposited at arXiv arXiv:1211.0719v2 [physics.soc-ph] ), which was subsequently published in Journal of Statistical Physics May 2013, Volume 151, Issue 3-4, pp 745-764. The final publication is available at link.springer.com http://link.springer.com/article/10.1007/s10955-013-0722-

    Carbon fiber masculinity: Disability and surfaces of homosociality

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    In this paper I am concerned with instances in which carbon fiber extends performances of masculinity that are attached to particular kinds of hegemonic male bodies. In examining carbon fiber as a prosthetic form of masculinity, I advance three main arguments. Firstly, carbon fiber can be a site of the supersession of disability that is affected through masculinized technology. Disability can be ‘overcome’ through carbon fiber. Disability is often culturally coded as feminine (Pedersen, 2001; Meeuf, 2009; Garland-Thompson 1997). Building on this cultural construction of disability as feminine, in and as a technology of masculine homosociality (Sedgwick, 1985), carbon fiber reproduced disability as feminine when carbon fiber prosthetic lower legs allowed Oscar Pistorius to compete in the non-disabled Olympic games. Secondly, I argue that carbon fiber can be a homosocial surface; that is, carbon fiber becomes both a surface extension of the self and a third party mediator in homosocial relationships, a surface that facilitates intimacy between men in ways that devalue femininity in both male and female bodies. I examine surfaces as material extensions of subjectivity, and carbon fiber surfaces as vectors of the cultural economies of masculine competition to which I refer. Thirdly, the case of Oscar Pistorius is exemplary of the masculinization of carbon fire, and the associated binding of a psychic attitude of misogyny and power to a form of violent and competitive masculine subjectivity. In this article I explore the affects, economies and surfaces of what I call ‘carbon fiber masculinity’ and discusses Pistorius’ use of carbon fiber, homosociality and misogyny as forms of protest masculinity through which he unconsciously attempted to recuperate his gendered identity from emasculating discourses of disability
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