741 research outputs found

    Canvas politics: Norman Lewis and the art of Abstract Resistance

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    Norman Lewis (1909-1979) is best remembered, perhaps erroneously, as the first African American Abstract Expressionist. In this dissertation, I argue that he is better suited as a Social Abstractionist and an Abstract Allusionist based on the life he lived, the work he produced, and his involvement in both black art and the Abstract Expressionist movement. ^ I begin by presenting a comprehensive overview of Lewis\u27 biography and oeuvre. Painting from the 1930s to the late 1970s, his aesthetic sensibilities can be categorized into three distinct phases: 1) in the 1930s, answering to the call for a new presentation of the Negro, Lewis, under the guidance of philosopher Alain Locke, painted in a style commonly associated with Social Realism; 2) in his second phase starting in the mid-1940s, Lewis, disillusioned with the inefficiency of painting Social Realist works, begin transitioning into a more abstract style of figuration; 3) in the final phase of his career from 1946 to the time of his death, Lewis worked on a series of fully abstracted paintings for which he became best known. During this time, Lewis developed his own symbolic language to present racially informed abstract paintings. My analysis will cover different ways to better understand Lewis\u27 position and contribution to the post World War II art scene in America. To this end, I call him both a Social Abstractionist and an Abstract Allusionist. I posit that these terms give new contexts to Lewis\u27 aesthetic, and demonstrate his innovations in fashioning his own complex cultural identity

    Adiabatic Elimination in Compound Quantum Systems with Feedback

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    Feedback in compound quantum systems is effected by using the output from one sub-system (``the system'') to control the evolution of a second sub-system (``the ancilla'') which is reversibly coupled to the system. In the limit where the ancilla responds to fluctuations on a much shorter time scale than does the system, we show that it can be adiabatically eliminated, yielding a master equation for the system alone. This is very significant as it decreases the necessary basis size for numerical simulation and allows the effect of the ancilla to be understood more easily. We consider two types of ancilla: a two-level ancilla (e.g. a two-level atom) and an infinite-level ancilla (e.g. an optical mode). For each, we consider two forms of feedback: coherent (for which a quantum mechanical description of the feedback loop is required) and incoherent (for which a classical description is sufficient). We test the master equations we obtain using numerical simulation of the full dynamics of the compound system. For the system (a parametric oscillator) and feedback (intensity-dependent detuning) we choose, good agreement is found in the limit of heavy damping of the ancilla. We discuss the relation of our work to previous work on feedback in compound quantum systems, and also to previous work on adiabatic elimination in general.Comment: 18 pages, 12 figures including two subplots as jpeg attachment

    Solutions of a certain class of fractional differintegral equations

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    AbstractRecently, several authors demonstrated the usefulness of fractional calculus in obtaining particular solutions of a number of such familiar second-order differential equations as those associated with Gauss, Legendre, Jacobi, Chebyshev, Coulomb, Whittaker, Euler, Hermite, and Weber equations. The main object of this paper is to show how some of the latest contributions on the subject by Tu et al. [1], involving the associated Legendre, Euler, and Hermite equations, can be presented in a unified manner by suitably appealing to a general theorem on particular solutions of a certain class of fractional differintegral equations

    Directly Observing Momentum Transfer in Twin-Slit "Which-Way" Experiments

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    Is the destruction of interference by a which-way measurement due to a random momentum transfer \wp\agt\hbar/s, with ss the slit separation? The weak-valued probability distribution Pwv()P_{\rm wv}(\wp), which is {\em directly observable}, provides a subtle answer. Pwv()P_{\rm wv}(\wp) cannot have support on the interval [/s,/s][-\hbar/s,\hbar/s]. Nevertheless, its moments can be identically zero.Comment: 5 pages, 1 figure. Almost the version almost accepted for publication in Phys. Lett.

    Spin squeezing via quantum feedback

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    We propose a quantum feedback scheme for producing deterministically reproducible spin squeezing. The results of a continuous nondemolition atom number measurement are fed back to control the quantum state of the sample. For large samples and strong cavity coupling, the squeezing parameter minimum scales inversely with atom number, approaching the Heisenberg limit. Furthermore, ceasing the measurement and feedback when this minimum has been reached will leave the sample in the maximally squeezed spin state.Comment: 4 pages, 3 figures, revtex

    Information sharing, bank penetration and tax evasion in emerging markets

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    Tax evasion, which is typically considered an illegal activity, is a critical problem and is considered a barrier to economic growth. A review of the literature shows that tax and social security contributions, regulations, public sector services, the quality of institutions and tax compliance, play important roles in determining the degree to which firms attempt to evade taxes. Measuring tax evasion is problematic due to data requirements and inadequacies. Few tax evasion indices have been estimated but it appears that they cannot be used for international comparisons across countries. This important issue has largely been ignored in the literature, in particular for emerging markets. Consequently, this paper is conducted to develop a new tax evasion index (TEI) using the most substantial and recent data from the standardized World Bank Enterprises Survey 2006–2017. In addition, using the newly developed TEI, the paper examines the importance and contribution of information sharing and bank penetration to the degree of tax evasion in emerging markets. The paper uses a sample of 112 emerging markets from 2006–2017 and the Tobit model in estimation. The empirical findings from the paper indicate that the average TEI during the 2006– 2017 period for emerging markets is 0.62, with a range of (0.25, 0.75). In addition, we find that information sharing and bank penetration negatively affect the degree of tax evasion, as proxied by the TEI, in emerging markets. The empirical results also confirm the view that large firms are considered to have adopted good tax compliance practices, while firms located in remote areas are more likely to evade taxes. Policy implications have emerged on the basis of the empirical findings from the paper

    A noticeable difference? Productivity costs related to paid and unpaid work in economic evaluations on expensive drugs

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    Productivity costs can strongly impact cost-effectiveness outcomes. This study investigated the impact in the context of expensive hospital drugs. This study aimed to: (1) investigate the effect of productivity costs on cost-effectiveness outcomes, (2) determine whether economic evaluations of expensive drugs commonly include productivity costs related to paid and unpaid work, and (3) explore potential reasons for excluding productivity costs from the economic evaluation. We conducted a systematic literature review to identify economic evaluation

    Can patterns of everyday consumption indicate lifestyles? A secondary analysis of expenditures for fast moving goods and their social contexts

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    Ausgangspunkt der vorliegenden Studie bildet die Frage, ob sich Einkaufsformen beim täglichen Verbrauch als grundlegende Indikatoren von Lebensstilen erweisen. Datengrundlage bildet eine Sekundäranalyse von Panel-Daten zum Konsum schnelllebiger Waren, die vom weltweiten Marktforschungsunternehmen GfK im Jahr 1995 erhoben worden sind. Es wird zunächst eine Reihe von Hypothesen aufgestellt und die zugrunde gelegten Daten und die Stichprobe erläutert. Im Hauptteil der Studie werden 15 vollständige Cluster des Kaufverhaltens von Waren aus den Bereichen Nahrungsmittel, Getränke und Hygiene-Artikel untersucht und mit ausgewählten sozialen Indikatoren, wie z.B. sozialer Status, Mentalität und Umweltbewusstsein in Beziehung gesetzt. Die Ergebnisse zeigen, dass selbst der Kauf von schnelllebigen Konsumgütern in breitere Lebensstile eingebettet ist und auch im Zeitverlauf relativ konstant bleibt. (ICI

    Integrated engineering environments for large complex products

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    An introduction is given to the Engineering Design Centre at the University of Newcastle upon Tyne, along with a brief explanation of the main focus towards large made-to-order products. Three key areas of research at the Centre, which have evolved as a result of collaboration with industrial partners from various sectors of industry, are identified as (1) decision support and optimisation, (2) design for lifecycle, and (3) design integration and co-ordination. A summary of the unique features of large made-to-order products is then presented, which includes the need for integration and co-ordination technologies. Thus, an overview of the existing integration and co-ordination technologies is presented followed by a brief explanation of research in these areas at the Engineering Design Centre. A more detailed description is then presented regarding the co-ordination aspect of research being conducted at the Engineering Design Centre, in collaboration with the CAD Centre at the University of Strathclyde. Concurrent Engineering is acknowledged as a strategy for improving the design process, however design coordination is viewed as a principal requirement for its successful implementation. That is, design co-ordination is proposed as being the key to a mechanism that is able to maximise and realise any potential opportunity of concurrency. Thus, an agentoriented approach to co-ordination is presented, which incorporates various types of agents responsible for managing their respective activities. The co-ordinated approach, which is implemented within the Design Co-ordination System, includes features such as resource management and monitoring, dynamic scheduling, activity direction, task enactment, and information management. An application of the Design Co-ordination System, in conjunction with a robust concept exploration tool, shows that the computational design analysis involved in evaluating many design concepts can be performed more efficiently through a co-ordinated approach
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