3,363 research outputs found

    Apparatus to measure the mid-infrared spectral emittance of cold powders in a vacuum

    Get PDF
    Apparatus for measuring mid-infrared spectral emission from cold powders in vacuu

    Functional co-monotony of processes with applications to peacocks and barrier options

    Get PDF
    We show that several general classes of stochastic processes satisfy a functional co-monotony principle, including processes with independent increments, Brownian diffusions, Liouville processes. As a first application, we recover some recent results about peacock processes obtained by Hirsch et al. which were themselves motivated by a former work of Carr et al. about the sensitivity of Asian Call options with respect to their volatility and residual maturity (seniority). We also derive semi-universal bounds for various barrier options.Comment: 27 page

    Diffusion, Cell Mobility, and Bandlimited Functions

    Get PDF
    The mechanism by which leukocytes steer toward a chemical attractant is not fully resolved. Experimental data suggest that these cells detect differences in concentration of chemoattractant over their surface and walk up the gradient. The problem has been considered theoretically only in stationary media, where the distribution of attractant is determined solely by diffusion. Experimentally, bulk flow has been allowed only unintentionally. Since bulk flow is characteristic of real systems, we examine a simple two-dimensional model incorporating both diffusion and an additional drift. The latter problem leads to an integral equation which is central also in the study of weighted Hilbert spaces of bandlimited functions. We find asymptotic expressions for the required solution by a Wiener-Hopf method adapted to a finite interval. We conclude that, without drift, the concentration does not vary detectably around the cell, but that drift inceases this variation substantially. Thus over model suggests that drift may play an important role in the cell\u27s chemotactic response

    Probation, credibility and justice

    Get PDF
    This paper explores the difficulties that arise for probation agencies or those that deliver community sanctions in developing and maintaining their credibility in prevailing ‘late-modern’ social conditions. It begins by questioning the limits of the pursuit and promise of ‘public protection’ as a source of credibility, and then proceeds to examine the emergence of an alternative strategy – based principally on reparation and ‘payback’ – in Scotland, arguing that these Scottish developments have much to say to the emerging debates in England and Wales (and elsewhere) about the ‘rehabilitation revolution’ and the proper use of imprisonment. The paper provides a critical account of the development and meaning of the Scottish version of ‘payback’, linking it to some important philosophical and empirical studies that may help to steer the development of payback away from a ‘merely punitive’ drift. In the conclusion, I argue that probation agencies and services need to engage much more deeply and urgently with their roles as justice services, rather than as ‘mere’ crime reduction agencies

    Ginzburg-Landau model with small pinning domains

    Full text link
    We consider a Ginzburg-Landau type energy with a piecewise constant pinning term aa in the potential (a2−∣u∣2)2(a^2 - |u|^2)^2. The function aa is different from 1 only on finitely many disjoint domains, called the {\it pinning domains}. These pinning domains model small impurities in a homogeneous superconductor and shrink to single points in the limit →ˇ0\v\to0; here, \v is the inverse of the Ginzburg-Landau parameter. We study the energy minimization in a smooth simply connected domain Ω⊂C\Omega \subset \mathbb{C} with Dirichlet boundary condition gg on \d \O, with topological degree {\rm deg}_{\d \O} (g) = d >0. Our main result is that, for small \v, minimizers have dd distinct zeros (vortices) which are inside the pinning domains and they have a degree equal to 1. The question of finding the locations of the pinning domains with vortices is reduced to a discrete minimization problem for a finite-dimensional functional of renormalized energy. We also find the position of the vortices inside the pinning domains and show that, asymptotically, this position is determined by {\it local renormalized energy} which does not depend on the external boundary conditions.Comment: 39 page

    Visions in monochrome: Families, marriage and the individualisation thesis

    Get PDF
    This paper takes issue with the way in which the individualisation thesis – in which it is assumed that close relationships have become tenuous and fragile - has become so dominant in ‘new’ sociological theorising about family life. Although others have criticised this thesis, in this paper the main criticism derives from empirical research findings carried out with members of transnational families living in Britain whose values and practices do not fit easily with ideas of individualisation. It is argued that we need a much more complex and less linear notion of how families change across generations and in time

    The two rival concepts of devotional leisure: Towards an understanding of Twenty-First Century human creativity and the possibility of freedom

    Get PDF
    The starting point of this article is that the ultimate objective of sociology so far as the study of leisure is concerned should be with understanding the ways in which twenty-first century modern men and women attempt to reconcile the demands of individuality and community (aka freedom and security) by focusing on what they choose to do when they can do anything at all. The first introductory part sets up the rest of the article by offering a brief critique of the sociology of leisure which operates with the somewhat startling assertion that in modern societies leisure is largely consumerist in orientation and that as a result freedom is a fiction. Counteracting this assertion with a startling one of its own it is subsequently argued that the twentieth century interregnum saw modernity radically revise its modernity which led to a transformation in the power of human agency and emergence of the insistent voice ‘I too am in individual’. Taking as its starting point Peter Sloterdijk’s reading of Nietzsche’s imperative to ‘Become who you are’ articulated passionately in his book You must change your life (2013), the second part of the article argues that in the twenty-first century terms like authentic leisure and consumerist leisure, work and leisure are not antithetical to one another, and there is a radical need to rethink how people give meaning and order to their lives though their leisure pursuits. Here the article explores the relationship between Sloterdijk’s concept of anthropotechnics, the art of living and leisure. The next part of the article fleshes out the theory of devotional leisure which is one part of a more embracing project set out in the book Re-imagining leisure studies (Blackshaw 2017). Here the article explores two contrasting ways of understanding devotional leisure practice, namely ‘devotional leisure’ and ‘performative leisure’ by drawing respectively on the examples of surfing and car cruising. The article concludes with an attempt to reconcile these two seemingly contradictory forms of devotional leisure practice with a discussion of urban exploration, speculating that their uniqueness to one another is never absolute, and the more you perceive their particularity, the more you understand their double nature, as simultaneously aspects of a third endeavour

    'Mine's a Pint of Bitter': Performativity, gender, class and representations of authenticity in real-ale tourism

    Get PDF
    Leisure choices are expressive of individual agency around the maintenance of taste, boundaries, identity and community. This research paper is part of a wider project designed to assess the social and cultural value of real ale to tourism in the north of England. This paper explores the performativity of real-ale tourism and debates about belonging in northern English real-ale communities. The research combines an ethnographic case study of a real-ale festival with semi-structured interviews with organisers and volunteers, northern English real-ale brewers and real-ale tourists visiting the festival. It is argued that real-ale tourism, despite its origins in the logic of capitalism, becomes a space where people can perform Habermasian, communicative leisure, and despite the contradictions of preferring some capitalist industries over others on the basis of their perceived smaller size and older age, real-ale fans demonstrate agency in their performativity
    • 

    corecore