2,073 research outputs found

    Accuracy: The fundamental requirement for voting systems

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    There have been several attempts to develop a comprehensive account of the requirements for voting systems, particularly for public elections. Typically, these approaches identify a number of "high level" principals which are then refined either into more detailed statements or more formal constructs. Unfortunately, these approaches do not acknowledge the complexity and diversity of the contexts in which voting takes place. This paper takes a different approach by arguing that the only requirement for a voting system is that it is accurate. More detailed requirements can then be derived from this high level requirement for the particular context in which the system is implemented and deployed. A general, formal high level model for voting systems and their context is proposed. Several related definitions of accuracy for voting systems are then developed, illustrating how the term "accuracy" is in interpreted in different contexts. Finally, a context based requirement for voting system privacy is investigated as an example of deriving a subsidiary requirement from the high level requirement for accuracy

    Responsibility modelling for risk analysis

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    Deriving Information Requirements from Responsibility Models

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    This paper describes research in understanding the requirements for complex information systems that are constructed from one or more generic COTS systems. We argue that, in these cases, behavioural requirements are largely defined by the underlying system and that the goal of the requirements engineering process is to understand the information requirements of system stakeholders. We discuss this notion of information requirements and propose that an understanding of how a socio-technical system is structured in terms of responsibilities is an effective way of discovering this type of requirement. We introduce the idea of responsibility modelling and show, using an example drawn from the domain of emergency planning, how a responsibility model can be used to derive information requirements for a system that coordinates the multiple agencies dealing with an emergency

    Akubras to Hard Hats: Easing Skills Shortages through Labour Harmonisation Strategies

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    This article examines skill and labour shortages within rural agricultural industries in Western Australia. It draws on primary and secondary data, including 600 survey respondents in the sector. It is determined that there may be a shortage of farm workers during the busy seasons, while they are unemployed during the low seasons. Consequently, it is proposed that a human capability framework is utilised to encourage farm owners and (or) workers to consider the potential for labour-harmonisation (LH) strategies which would allow workers to transit between working on the land during the busy seasons and in mining during the low seasons. The outcomes of the study are considered in relation to indicators of precarious work illustrating that LH could enable an easing of labour shortages for both the farming and mining sectors, while providing benefits for the respective workers, employers, and the region in general

    A comparison of incompressible limits for resistive plasmas

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    The constraint of incompressibility is often used to simplify the magnetohydrodynamic (MHD) description of linearized plasma dynamics because it does not affect the ideal MHD marginal stability point. In this paper two methods for introducing incompressibility are compared in a cylindrical plasma model: In the first method, the limit Ī³ā†’āˆž\gamma \to \infty is taken, where Ī³\gamma is the ratio of specific heats; in the second, an anisotropic mass tensor Ļ\mathbf{\rho} is used, with the component parallel to the magnetic field taken to vanish, Ļāˆ„ā†’0\rho_{\parallel} \to 0. Use of resistive MHD reveals the nature of these two limits because the Alfv\'en and slow magnetosonic continua of ideal MHD are converted to point spectra and moved into the complex plane. Both limits profoundly change the slow-magnetosonic spectrum, but only the second limit faithfully reproduces the resistive Alfv\'en spectrum and its wavemodes. In ideal MHD, the slow magnetosonic continuum degenerates to the Alfv\'en continuum in the first method, while it is moved to infinity by the second. The degeneracy in the first is broken by finite resistivity. For numerical and semi-analytical study of these models, we choose plasma equilibria which cast light on puzzling aspects of results found in earlier literature.Comment: 14 pages, 10 figure

    Osteology and myology of the head and neck of the pied-billed grebes (Podilymbus)

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    http://deepblue.lib.umich.edu/bitstream/2027.42/56383/1/MP139.pd

    How cultural capital emerged in Gilded Age America: musical purification and cross-class inclusion at the New York Philharmonic

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    This article uses a new database of subscribers to the New York Philharmonic to explore how high culture became a form of socially valuable capital in late-19th-century America. The authors find support for the classic account of high culture?s purification and exclusiveness, showing how over the long Gilded Age the social elite of New York attended the Philharmonic both increasingly and in more socially patterned ways. Yet they also find that the orchestra opened up to a new group of subscribers hailing from an emerging professional, managerial, and intellectual middle class. Importantly, the inclusion of this new audience was segregated: they did not mingle with elites in the concert hall. This segregated inclusion paved a specific way for the constitution of cultural capital. It meant that greater purity and greater inclusiveness happened together, enabling elite cultural participation to remain distinctive while elite tastes acquired broader social currency

    Stability and transport of parallel velocity shear driven mode with negative magnetic shear

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    The linear and quasilinear behavior of the drift-like perturbation with a parallel velocity shear is studied in a sheared slab geometry. Full analytic studies show that when the magnetic shear has the same sign as the second derivative of the parallel velocity with respect to the radial coordinate, the linear mode may become unstable and turbulent momentum transport increases. On the other hand, when the magnetic shear has opposite sign to the second derivative of the parallel velocity, the linear mode is completely stabilized and turbulent momentum transport reduces

    Benzoylamidoacetonitrile is bound as a thioimidate in the active site of papain.

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    13C NMR spectroscopy has been used to demonstrate that 13CN-labeled benzoylamidoacetonitrile forms a covalent adduct with the thiol group of cysteine 25 in the active site of papain. Spectral comparison with model compounds indicates that the adduct is a thioimidate. On the basis of a proposed mechanism for the formation of the thioimidate, it is concluded that the -CH2C(= NH)S--imino nitrogen does not sit in the active site in the same manner as the thiol ester carbonyl oxygen of the thiol acyl enzyme (or the oxyanion of the tetrahedral intermediate). Thus, in this sense the stabilization of the thioimidate does not reflect a similarity in structure between the bound thioimidate and the transition state
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