3,843 research outputs found

    Convolutional Radio Modulation Recognition Networks

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    We study the adaptation of convolutional neural networks to the complex temporal radio signal domain. We compare the efficacy of radio modulation classification using naively learned features against using expert features which are widely used in the field today and we show significant performance improvements. We show that blind temporal learning on large and densely encoded time series using deep convolutional neural networks is viable and a strong candidate approach for this task especially at low signal to noise ratio

    Critical properties of the unconventional spin-Peierls system TiOBr

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    We have performed detailed x-ray scattering measurements on single crystals of the spin-Peierls compound TiOBr in order to study the critical properties of the transition between the incommensurate spin-Peierls state and the paramagnetic state at Tc2 ~ 48 K. We have determined a value of the critical exponent beta which is consistent with the conventional 3D universality classes, in contrast with earlier results reported for TiOBr and TiOCl. Using a simple power law fit function we demonstrate that the asymptotic critical regime in TiOBr is quite narrow, and obtain a value of beta_{asy} = 0.32 +/- 0.03 in the asymptotic limit. A power law fit function which includes the first order correction-to-scaling confluent singularity term can be used to account for data outside the asymptotic regime, yielding a more robust value of beta_{avg} = 0.39 +/- 0.05. We observe no evidence of commensurate fluctuations above Tc1 in TiOBr, unlike its isostructural sister compound TiOCl. In addition, we find that the incommensurate structure between Tc1 and Tc2 is shifted in Q-space relative to the commensurate structure below Tc1.Comment: 12 pages, 8 figures. Submitted to Physical Review

    Networks as ‘laboratories of experience’: exploring the life cycle of the suffrage movement and its aftermath in Ireland 1870–1937

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    Applying an innovative conceptual framework this article presents an interdisciplinary re-appraisal of the suffrage movement and its aftermath in Ireland throughout the years 1870–1937. New social movement theory is utilised to consider how, in the words of the Italian sociologist Alberto Melucci ‘the submerged networks of social movements are laboratories of experience’. Going beyond the previously published work of each author, this article uses the sociological lens of ‘laboratories of experience’ to re-analyse aspects of the suffrage movement, female activism and the wider women's movement in Ireland. This application of social movement theory to female networks, their origins, aims and strategies, along with their interconnectedness, provides a more nuanced and detailed understanding of the ‘life-cycle’ of this movement. The article aims to demonstrate how an analysis of network dynamics and application of the concept of ‘latency’ is useful in further understanding the significance, impact and longevity of the women's movement in Ireland

    Issues in microenterprise employment, production and coping strategies in post-devaluation Dakar : the case of garment-making and woodworking firms

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    Thesis (M.C.P.)--Massachusetts Institute of Technology, Dept. of Urban Studies and Planning, 1996.Includes bibliographical references (p. 85-87).by John C. Powers, Jr.M.C.P

    Commensurate Fluctuations in the Pseudogap and Incommensurate spin-Peierls Phases of TiOCl

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    X-ray scattering measurements on single crystals of TiOCl reveal the presence of commensurate dimerization peaks within both the incommensurate spin-Peierls phase and the so-called pseudogap phase above T_c2. This scattering is relatively narrow in Q-space indicating long correlation lengths exceeding ~ 100 A below T* ~ 130 K. It is also slightly shifted in Q relative to that of the commensurate long range ordered state at the lowest temperatures, and it coexists with the incommensurate Bragg peaks below T_c2. The integrated scattering over both commensurate and incommensurate positions evolves continuously with decreasing temperature for all temperatures below T* ~ 130 K.Comment: To appear in Physical Review B: Rapid Communications. 5 page

    Suppression of the commensurate spin-Peierls state in Sc-doped TiOCl

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    We have performed x-ray scattering measurements on single crystals of the doped spin-Peierls compound Ti(1-x)Sc(x)OCl (x = 0, 0.01, 0.03). These measurements reveal that the presence of non-magnetic dopants has a profound effect on the unconventional spin-Peierls behavior of this system, even at concentrations as low as 1%. Sc-doping suppresses commensurate fluctuations in the pseudogap and incommensurate spin-Peierls phases of TiOCl, and prevents the formation of a long-range ordered spin-Peierls state. Broad incommensurate scattering develops in the doped compounds near Tc2 ~ 93 K, and persists down to base temperature (~ 7 K) with no evidence of a lock-in transition. The width of the incommensurate dimerization peaks indicates short correlation lengths on the order of ~ 12 angstroms below Tc2. The intensity of the incommensurate scattering is significantly reduced at higher Sc concentrations, indicating that the size of the associated lattice displacement decreases rapidly as a function of doping.Comment: 7 pages, 5 figure

    Acupuncture for treatment of alcohol dependence - establishment of collaboration with St George’s Mental Health NHS Trust and Community Drug Service South London

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    Alcohol dependence is an increasing social problem. In the UK, the NHS estimates that around 9% of men and 4% of women show signs of alcohol dependence. Acupuncture, as a treatment for addiction, can be integrated into a comprehensive programme to combat alcohol dependence. There have been research studies into the effectiveness of acupuncture to treat alcohol dependence and its related mental health disorders. However, although some findings are positive, they are still not sufficient or conclusive. Two questions need to be answered. The first is whether or not acupuncture is effective in treating alcohol addiction and its associated physiological and psychological symptoms, and the second is whether acupuncture is effective in preventing recidivism. We have established cooperation between our School, South West London and St George’s Mental Health NHS Trust and Community Drug Service South London (CDS). Since January 2015, some alcohol dependent clients have been given acupuncture, and their clinical records show that acupuncture may be effective in helping prevent recidivism. The hypothesis of this research is that acupuncture is effective in treating alcohol dependence by helping addicts quit alcohol drinking and maintain abstinence, and acupuncture has positive effects on symptoms of withdrawal and quality of life. This paper will present the aims and stages of this practical research and will demonstrate how we will measure the effect of treatment on the management of the clients’ addiction to alcohol
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