46 resultados para Conceptions of Mathematics
Resumo:
We give a necessary and sufficient condition for amenability of the Banach algebra of approximable operators on a Banach space. We further investigate the relationship between amenability of this algebra and factorization of operators, strengthening known results and developing new techniques to determine whether or not a given Banach space carries an amenable algebra of approximable operators. Using these techniques, we are able to show, among other things, the non-amenability of the algebra of approximable operators on Tsirelson’s space.
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Attracting in-migration of the creative class has been argued by Florida (2002) to be a route to higher economic growth in the era of the knowledge economy. This paper critically evaluates this proposition in relation to old industrial regions using the example of Scotland. The paper presents an assessment of, in the first instance, to what extent there is a shortage of skilled, talented and entrepreneurial individuals and, in the second instance, whether a talent attraction strategy alone can hope to attract such people to Scotland. It is proposed that for most migrants the availability of appropriate economic opportunities is a prerequisite for mobility. However, despite uncertain evidence that place attractiveness is a catalyst to mobility among the so-called creative class, this is not a reason for dismissing talent attraction programmes. Instead it is argued that talent attraction programmes have the potential to contribute to old industrial economies, but their success will be greatest when talent attraction is carefully targeted and based on economic realities rather than the marketing of ethereal conceptions of place attractiveness.
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The reduced Whitehead group $\SK$ of a graded division algebra graded by a torsion-free abelian group is studied. It is observed that the computations here are much more straightforward than in the non-graded setting. Bridges to the ungraded case are then established by the following two theorems: It is proved that $\SK$ of a tame valued division algebra over a henselian field coincides with $\SK$ of its associated graded division algebra. Furthermore, it is shown that $\SK$ of a graded division algebra is isomorphic to $\SK$ of its quotient division algebra. The first theorem gives the established formulas for the reduced Whitehead group of certain valued division algebras in a unified manner, whereas the latter theorem covers the stability of reduced Whitehead groups, and also describes $\SK$ for generic abelian crossed products.
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Sketches and photographs are a familiar tool of the traveller-writer, who commonly draws on them when transforming experience into a textual narrative. The verbal thus displaces the visual — the latter retained, if at all, as mere illustration — in ways that echo James Heffernan's definition of ekphrasis as the ‘verbal description of visual representation’. Yet Nicolas Bouvier's 1963 travel narrative L'Usage du monde challenges conventional conceptions of ekphrasis. Juxtaposing the stark ink drawings of Thierry Vernet — Bouvier's travelling companion — with Bouvier's textual narrative, L'Usage du monde shifts representation away from a hierarchical relationship between verbal and visual; it offers instead an account of other cultures that is grounded in polyphony and exchange. This article applies Bouvier's own image of travel as a mosaic to the dual narrative form (or ‘iconotext’, to use Michael Nerlich's term) in order to consider a range of fluid relationships between Bouvier's text and Vernet's drawings. In examining these relationships of amplification, reduction, and absence, the article argues that the plurality of the narrative prompts a rethinking of conventional, binary paradigms of intercultural contact. Ultimately, the iconotextual nature of L'Usage du monde can be interpreted as a metaphor for the processes of cultural translation and transculturation that are central to Bouvier's travelling ethos.
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Let D be the differentiation operator Df = f' acting on the Fréchet space H of all entire functions in one variable with the standard (compact-open) topology. It is known since the 1950’s that the set H(D) of hypercyclic vectors for the operator D is non-empty. We treat two questions raised by Aron, Conejero, Peris and Seoane-Sepúlveda whether the set H(D) contains (up to the zero function) a non-trivial subalgebra of H or an infinite-dimensional closed linear subspace of H. In the present article both questions are answered affirmatively.
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In this paper, I question modes of listening in network music performance environments, and specifically draw on my experience as a performer listening in these scenarios. I situate network listening within the context of current music making, and refer to changes in compositional practices that draw specific attention to listening. I argue that some of these compositional developments play a determining role in articulating a new discourse of listening. Eric Satie's concept of Furniture Music, Schaeffer's ideas on reduced listening, Oliveros' deep listening practices as well as digital music platforms all serve to show a development towards a proliferation in listening experiences. I expand this narrative to listening practices in network performance environments, and identify a specific bodily fragility in listening in and to the network. This fragile state of listening and de-centered kind of performative being allow me to draw parallels to the Japanese art form Butoh and Elaine Scarry's metaphor of beauty. My own performance experiences, set within the context of several critical texts, allow me to see network[ed] listening as an ideal corporeal state, which offers a rethinking of linear conceptions of the other and a subject's own relation with her world. Ultimately, network[ed] listening posits listening as a corporeal and multi-dimensional experience that is continuously being re-shaped by technological, socio-political and cultural concerns.
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This paper examines the structure of popular conceptions of the new genetics, and assesses why genetics has been so readily accepted in medicine and in the public discourse. Adapting Rene Dubos' classic analysis, Mirage of Health, we examine the new genetics by comparing it to Dubos' analysis of the structure and limits of germ theory. Germ theory focuses on the internal rather than the external environment, emphasises a doctrine of specific aetiology, and adopts the metaphor of the body as a machine. The germ theory model narrowed our vision about disease aetiology, proved misleading in some cases, yet remained the basis for clinical medical models of disease. In recent years, genetics has moved to the cutting edge of medical research and thinking about disease and behaviour. The structure of popular conceptions of the new genetics shows remarkable parallels with germ theory. This has eased the acceptance of genetics but simultaneously raises questions about these genetic explanations. An appearance and allure of specificity privileges genetic explanations in the public discourse; on examination, this specificity may prove to be a mirage.
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In conditional probabilistic logic programming, given a query, the two most common forms for answering the query are either a probability interval or a precise probability obtained by using the maximum entropy principle. The former can be noninformative (e.g.,interval [0; 1]) and the reliability of the latter is questionable when the priori knowledge isimprecise. To address this problem, in this paper, we propose some methods to quantitativelymeasure if a probability interval or a single probability is sufficient for answering a query. We first propose an approach to measuring the ignorance of a probabilistic logic program with respect to a query. The measure of ignorance (w.r.t. a query) reflects howreliable a precise probability for the query can be and a high value of ignorance suggests that a single probability is not suitable for the query. We then propose a method to measure the probability that the exact probability of a query falls in a given interval, e.g., a second order probability. We call it the degree of satisfaction. If the degree of satisfaction is highenough w.r.t. the query, then the given interval can be accepted as the answer to the query. We also prove our measures satisfy many properties and we use a case study to demonstrate the significance of the measures. © Springer Science+Business Media B.V. 2012
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Political parties have only recently become a subject of investigation in political theory. In this paper I analyse religious political parties in the context of John Rawls’s political liberalism. Rawlsian political liberalism, I argue, overly constrains the scope of democratic political contestation and especially for the kind of contestation channelled by parties. This restriction imposed upon political contestation risks undermining democracy and the development of the kind of democratic ethos that political liberalism cherishes. In this paper I therefore aim to provide a broader and more inclusive understanding of ‘reasonable’ political contestation, able to accommodate those parties (including religious ones) that political liberalism, as customarily understood, would exclude from the democratic realm. More specifically, I first embrace Muirhead and Rosenblum’s (Perspectives on Politics 4: 99–108 2006) idea that parties are ‘bilingual’ links between state and civil society and I draw its normative implications for party politics. Subsequently, I assess whether Rawls’s political liberalism is sufficiently inclusive to allow the presence of parties conveying religious and other comprehensive values. Due to Rawls’s thick conceptions of reasonableness and public reason, I argue, political liberalism risks seriously limiting the number and kinds of comprehensive values which may be channelled by political parties into the public political realm, and this may render it particularly inhospitable to religious political parties. Nevertheless, I claim, Rawls’s theory does offer some scope for reinterpreting the concepts of reasonableness and public reason in a thinner and less restrictive sense and this may render it more inclusive towards religious partisanship.
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This paper investigates the distribution of the condition number of complex Wishart matrices. Two closely related measures are considered: the standard condition number (SCN) and the Demmel condition number (DCN), both of which have important applications in the context of multiple-input multipleoutput (MIMO) communication systems, as well as in various branches of mathematics. We first present a novel generic framework for the SCN distribution which accounts for both central and non-central Wishart matrices of arbitrary dimension. This result is a simple unified expression which involves only a single scalar integral, and therefore allows for fast and efficient computation. For the case of dual Wishart matrices, we derive new exact polynomial expressions for both the SCN and DCN distributions. We also formulate a new closed-form expression for the tail SCN distribution which applies for correlated central Wishart matrices of arbitrary dimension and demonstrates an interesting connection to the maximum eigenvalue moments of Wishart matrices of smaller dimension. Based on our analytical results, we gain valuable insights into the statistical behavior of the channel conditioning for various MIMO fading scenarios, such as uncorrelated/semi-correlated Rayleigh fading and Ricean fading. © 2010 IEEE.
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In June and November 2000, the European Parliament and the Council adopted two Directives referring to ‘the principle of equal treatment irrespective of’ in their title, one relating to racial and ethnic origin, the other to disability, age, religion and belief or sexual orientation. A thorough reform of Directive 76/207/EEC on the principle of equal treatment for women and men in employment matters is pending between the European Parliament's second reading and adoption while this is written. Community secondary legislation on equal treatment of persons has thus expanded in scope and number of reasons which must not serve as starting points for differentiation. Does this signify progress in legal protection against personal discrimination? While not providing a ready answer, this article proposes an analytical framework to answer this question, concentrating on conceptions of equality in general and in particular on the problems multi-dimensional discrimination might pose for the law.
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We use representations of operator systems as quotients to deduce various characterisations of the weak expectation property (WEP) for C∗ -algebras. By Kirchberg’s work on WEP, these results give new formulations of Connes’ embedding problem.
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The recent electoral triumphs of the Democratic Unionist Party (DUP) have stimulated debate about the role of fundamentalist or ‘traditional evangelical’ Protestantism within the party and in Northern Irish politics. This paper argues that a significant restructuring of evangelical politics is taking place, one that is interest group‐centred rather than DUP‐centred. This process has been facilitated by changes in the structure of civil society. Traditional evangelical interest groups are ‘reframing’ their political projects in surprising new ways: abandoning Calvinist conceptions of church and state, using discourses of marginalisation and discrimination, and focusing on ‘moral’ issues. These subtle shifts in rhetoric constitute an acceptance of the post‐Belfast Agreement order. Rather than the tired, ‘Ulster Says No’ politics of the past, evangelicals are speaking out with a pragmatic ‘maybe’. This move parallels and reinforces the DUP’s ideological shifts, and provides an extra‐party platform for evangelicals to impact politics.
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A pilot study to investigate the effects of mathematics peer tutoring in Irish medium primary schools was undertaken. Five schools and 90 students took part in the pilot. Materials and resources that had previously been shown to work in English medium Scottish schools were translated into Irish by CCEA. Irish medium teachers attended three professional development days. Teachers implemented the peer tutoring techniques during mathematics lessons during a period of 16 weeks. Changes in attainment were measures with an Irish translation of the Scottish Survey of Achievement Mathematics Test. Results were positive. Student attainment was significantly raised during the 16-week implementation period by over one standard deviation. This equated to one-year’s worth of mathematics development during this time period. Results must be treated with caution. No control group was used in the pilot study. However, results are very promising and indicate that reciprocal role peer tutoring may be a useful pedagogy in Irish medium education. Further work would be required to establish this definitively.
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The provision of mathematics learning support in higher-level institutions on the island of Ireland has developed rapidly in recent times with the number of institutions providing some form of support doubling in the past seven years. The Irish Mathematics Learning Support Network aims to inform all mathematics support practitioners in Ireland on relevant issues. Consequently it was decided that a detailed picture of current provision was necessary. A comprehensive online survey was conducted to amass the necessary data. The ultimate aim of the survey is to benefit all mathematics support practitioners in Ireland, in particular those in third-level institutions who require further support to enhance the mathematical learning experience of their students. The survey reveals that the majority of Irish higher-level institutions provide mathematics learning support to some extent, with 65% doing so through a support centre. Learners of service mathematics are the primary users: first-year science, engineering and business undergraduates, with non-traditional students being a sizeable element. Despite the growing recognition for the need to offer mathematics learning support almost half of the centres are subject to annual review. Further, less than half the support offerings have a dedicated full-time manager, while 60% operate with a staff of five or fewer. The elevation of mathematics support as a viable and worthwhile career in order to attract and retain high quality staff is seen by many respondents as the crucial next phase of development.