920,437 research outputs found

    Variations on the Author

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    “Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship

    Hyperfine interaction and spin decoherence in quantum dots

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    Hyperfine interaction is a typical example of a topic in physics, that, due to technological advances, experiences a revival. Originally, hyperfine interaction was studied in atomic physics. In atoms, the interaction between the magnetic moments of the electrons and the nucleus leads to the hyperfine structure. The name hyperfine is historically due to the fact that the energy level splittings in atoms due to spin-orbit interaction were discovered first, and referred to as the atomic fine structure. The further splitting of these levels was then named hyperfine structure and the interaction that gives rise to it hyperfine interaction. In recent years, with the rise of nanotechnology, new structures have been created, one of them being so-called quantum dots. Quantum dots are also called artificial atoms, since, like atoms, they confine electrons to tiny (nanometer-size) regions. As for atoms, there is also hyperfine interaction in quantum dots: the spin of an electron confined to a quantum dot interacts with the lattice nuclei. In contrast to atoms, which have properties that are “given” by nature, the properties of quantum dots can be designed and thus allow to not only study new phenomena, but also open the way for new applications. Quantum computing is one of these applications where quantum dots could play an important role. The basic building block for a quantum computer is a quantum bit (qubit). Like a classical bit a qubit is an ideal two-level system. However, a qubit is a quantum mechanical two-level system instead of a classical one. There are several requirements a quantum-mechanical twolevel system has to fulfill to be a good qubit. The requirement central in this thesis is that the two states of the qubit and their superpositions should be long lived. More precisely it is crucial that coherent superpositions of the two states remain coherent for a long time compared to the manipulation time, i.e., that decoherence (the loss of coherence) is sufficiently slow. One promising candidate for the physical implementation of a qubit is the spin of an electron confined in a quantum dot. In an applied magnetic field the spin component along the field direction forms a natural two-level system. Research in the last few years, parts of which are being presented in this thesis, has shown that the main source of decoherence for spins in quantum dots is the hyperfine interaction with the surrounding nuclei in the host material. Since the wave function of an electron confined to a quantum dot extends over many sites of the underlying cristal lattice, the electron spin also interacts with many nuclei, in sharp contrast to an electron spin in an atom, which only interacts with a single nucleus. In this thesis we address several aspects of hyperfine interaction and decoherence in quantum dots. First, we analyze some aspects of the decoherence that arises from the hyperfine interaction. In the case of driven single-spin oscillations we show that hyperfine interaction leads to a universal phase shift and a power-law decay. Both of these effects have been confirmed experimentally. We also find a universal phase shift and a power-law decay for the case of two electron spins in a double quantum dot in the subspace with total spin zero along the quantization axis. The appearance of the these effects both in single and in double quantum dots is a consequence of the non-Markovian nature of the nuclear spin bath. Since the main effect of hyperfine-induced decoherence can be attributed to the uncertainty in the Overhauser field, the effective magnetic field generated by the nuclei at the position of the electron, one strategy to reduce decoherence is to prepare the nuclei in a state with a narrow Overhauser field distribution, i.e., to narrow the nuclear spin state. We propose a method to measure the Overhauser field using the dynamics of the electron spins as a probe. More specifically, we propose to narrow the nuclear spin state by monitoring Rabi oscillations in a double quantum dot. Hyperfine interaction not only leads to decoherence of the electron spin state, it also provides a mechanism for interaction between the nuclei in the quantum dot. We study the dynamics of the Overhauser field under the mutual interaction between nuclear spins that is mediated by the electron via the hyperfine interaction. At high magnetic fields we find an incomplete decay of the Overhauser field. We further show that the decay of the Overhauser field can be suppressed by measuring the Overhauser field, a clear manifestation of the quantum Zeno effect

    Appropriate Similarity Measures for Author Cocitation Analysis

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    We provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis

    The construction of Karen Karnak: The multi-author-function

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    This thesis is situated within the comparatively recent developments of Web 2.0 and the emergence of interactive WikiMedia, and explores the mode of authorship within a Read/Write culture compared to that of a Read/Only tradition. The hypothesis of this study is that the role of the audience has become merged with the author, and as such, represents new functions and attributes, distinct from a more conventional concept of authorship, in which the roles of audience and author are more separate. Read/Write and participatory culture, as defined by this study, is focused on collaboration, and includes the influences of D.I.Y. culture, Open-Source practices and the production of text by multiple authors. Multi-authorship presents a re-thinking of several concepts which support the notion of the individual author, since the focus of multi-authorship is not on attribution and ownership of a finished text, but on the continued malleability of a text. Modes of multi-authorship, demonstrated in the use of the pseudonyms Alan Smithee and Karen Eliot, represent declarative authors whose names signify multiple origins, whilst concurrently indicating a distinct body of work. The function of these names form an important context to this study, since primary research involves the construction of an experimental mode of multi-authorship utilising WikiMedia technology and the interaction of thirty nine participants, who are invited to create a body of work under the collective pseudonym Karen Karnak. The data generated by this experiment is analysed using aspects of Michel Foucault's author-function to identify and determine power structures inherent in the WikiMedia context. The interplay of power structures, including concepts such as identity, ownership and the body of work, affect the resulting mode of authorship and contribute to the construction of Karen Karnak, suggesting further areas of research into the emerging multi-author

    Dispelling the Myths Behind First-author Citation Counts

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    We conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more sophisticated methods

    PSYNDEX Tests Review für RD 1-2 - TEST ZUR RECHTSCHREIBDIAGNOSE 1-2

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    This is a PSYNDEX Tests Review of RD 1-2 - TEST ZUR RECHTSCHREIBDIAGNOSE 1-2. PSYNDEX Tests Reviews are written in German and describe and evaluate psychological and educational tests used in the German-speaking countries. PSYNDEX Tests is offered by the Leibniz Institute for Psychology as open access documentation.Das ist ein PSYNDEX Tests Review zu RD 1-2 - TEST ZUR RECHTSCHREIBDIAGNOSE 1-2. PSYNDEX Tests Reviews beschreiben und bewerten zentrale psychologische und pädagogische Testverfahren, die in den deutschsprachigen Ländern eingesetzt werden, nach einem standardisierten Raster. PSYNDEX Tests wird durch das Leibniz-Institut für Psychologie als Open Access Dokumentation angeboten.publishedVersio

    Vidéosurveillance et insécurités urbaines : Etude de l'efficacité préventive du dispositif de caméras installé au quartier des Pâquis à Genève

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    Abstract. Drawing upon police statistics, this paper explores the impacts of the videosurveillance cameras (CCTV) installed in November 2014 in the Pâquis neighborhood in Geneva. It focuses on the evolution of criminality within the filmed perimeter and nearby settings. This analysis completes a previous article on the perceived safety of residents (Klauser and Kaenzig, 2017). In line with former studies, our results underline the limited preventive effects of the CCTV system. The analysis shows that cameras are inducing criminality displacement, mainly of drug trafficking. Overall, this study provides a differentiated and complex image of CCTV systems as instruments of territorialization of monitored areas. </jats:p

    koamabayili/VECTRON-author-checklist: VECTRON author checklist

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    We have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used

    Vidéosurveillance et insécurités urbaines : Etude de l'efficacité préventive du dispositif de caméras installé au quartier des Pâquis à Genève

    No full text
    Drawing upon police statistics, this paper explores the impacts of the videosurveillance cameras (CCTV) installed in November 2014 in the Pâquis neighborhood in Geneva. It focuses on the evolution of criminality within the filmed perimeter and nearby settings. This analysis completes a previous article on the perceived safety of residents (Klauser and Kaenzig, 2017). In line with former studies, our results underline the limited preventive effects of the CCTV system. The analysis shows that cameras are inducing criminality displacement, mainly of drug trafficking. Overall, this study provides a differentiated and complex image of CCTV systems as instruments of territorialization of monitored areas

    Author Under Sail The Imagination of Jack London, 1893-1902

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    In Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Intro -- Title Page -- Copyright Page -- Dedication -- Contents -- Acknowledgments -- Introduction -- 1. Spirit Truth -- 2. From Absorption to Theatricality and Back Again -- 3. "I Will Build a New Present" -- 4. Sons as Authors -- 5. Fathers as Publishers -- 6. The Daughter as Author -- 7. Lovers as Authors -- 8. At Sea with the Family -- 9. Yellow News, Yellow Stories -- 10. The Return Home -- Notes -- Bibliography -- Index -- About Jay WilliamsIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
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