32,988 research outputs found
Housing professionalism in the United Kingdom: the final curtain or a new age?
The unusually large, predominantly municipal, housing sector in the UK has provided the context for a large occupational grouping of "housing managers" that has claimed professional status. However, within the post-1945 British welfare state this professional project enjoyed limited success and social housing remained a fragile professional domain. This article explores the consequences for housing professionalism of the recent displacement of the bureau-professional "organisational settlement" by that characterising an emerging "managerial state". Managerialism constitutes a clear challenge to established forms of "professionalism", especially a weak profession such as housing management. However, professionalism is temporally and culturally plastic. Hence, the demands of managerialism, within the specific context of New Labour's quest for "community" cohesion, may be providing opportunities for a new urban network professionalism founded on claims to both generic and specific skills and also a knowledge base combining abstraction with local concreteness. The prominence in these networks of erstwhile "housing" practitioners may become the basis for a new, quite different, professional project. This argument is developed through both conceptual exploration and reference to empirical research. The latter involves reference to recent work by the authors on, first, the perception of housing employers of the changing nature and demands of "housing" work and its consequences for professionalism and, secondly, the professional project implications of the increasing prominence of neighbourhood management.</p
Majorana spinors and extended Lorentz symmetry in four-dimensional theory
An extended local Lorentz symmetry in four-dimensional (4D) theory is
considered. A source of this symmetry is a group of general linear
transformations of four-component Majorana spinors GL(4,M) which is isomorphic
to GL(4,R) and is the covering of an extended Lorentz group in a 6D Minkowski
space M(3,3) including superluminal and scaling transformations. Physical
space-time is assumed to be a 4D pseudo-Riemannian manifold. To connect the
extended Lorentz symmetry in the M(3,3) space with the physical space-time, a
fiber bundle over the 4D manifold is introduced with M(3,3) as a typical fiber.
The action is constructed which is invariant with respect to both general 4D
coordinate and local GL(4,M) spinor transformations. The components of the
metric on the 6D fiber are expressed in terms of the 4D pseudo-Riemannian
metric and two extra complex fields: 4D vector and scalar ones. These extra
fields describe in the general case massive particles interacting with an extra
U(1) gauge field and weakly interacting with ordinary particles, i.e.
possessing properties of invisible (dark) matter.Comment: 24 page
TropicalâNorth Pacific Climate Linkages over the Past Four Centuries
Analyses of instrumental data demonstrate robust linkages between decadal-scale North Pacific and tropical Indo-Pacific climatic variability. These linkages encompass common regime shifts, including the noteworthy 1976 transition in Pacific climate. However, information on Pacific decadal variability and the tropical high-latitude climate connection is limited prior to the twentieth century. Herein tree-ring analysis is employed to extend the understanding of North Pacific climatic variability and related tropical linkages over the past four centuries. To this end, a tree-ring reconstruction of the December-May North Pacific index (NPI)-an index of the atmospheric circulation related to the Aleutian low pressure cell-is presented (1600-1983). The NPI reconstruction shows evidence for the three regime shifts seen in the instrumental NPI data, and for seven events in prior centuries. It correlates significantly with both instrumental tropical climate indices and a coral-based reconstruction of an optimal tropical Indo-Pacific climate index, supporting evidence for a tropical-North Pacific link extending as far west as the western Indian Ocean. The coral-based reconstruction (1781-1993) shows the twentieth-century regime shifts evident in the instrumental NPI and instrumental tropical Indo-Pacific climate index, and three previous shifts. Changes in the strength of correlation between the reconstructions over time, and the different identified shifts in both series prior to the twentieth century, suggest a varying tropical influence on North Pacific climate, with greater influence in the twentieth century. One likely mechanism is the low-frequency variability of the El Nino-Southern Oscillation (ENSO) and its varying impact on Indo-Pacific climate.</p
Beyond capitalism and liberal democracy: on the relevance of GDH Coleâs sociological critique and alternative
This article argues for a return to the social thought of the often ignored early 20th-century English thinker GDH Cole. The authors contend that Cole combined a sociological critique of capitalism and liberal democracy with a well-developed alternative in his work on guild socialism bearing particular relevance to advanced capitalist societies. Both of these, with their focus on the limitations on âfree communal serviceâ in associations and the inability of capitalism to yield emancipation in either production or consumption, are relevant to social theorists looking to understand, critique and contribute to the subversion of neoliberalism. Therefore, the authors suggest that Coleâs associational sociology, and the invitation it provides to think of formations beyond capitalism and liberal democracy, is a timely and valuable resource which should be returned to
Reconstruction Analysis of Galaxy Redshift Surveys: A Hybrid Reconstruction Method
In reconstruction analysis of galaxy redshift surveys, one works backwards
from the observed galaxy distribution to the primordial density field in the
same region, then evolves the primordial fluctuations forward in time with an
N-body code. This incorporates assumptions about the cosmological parameters,
the properties of primordial fluctuations, and the biasing relation between
galaxies and mass. These can be tested by comparing the reconstruction to the
observed galaxy distribution, and to peculiar velocity data. This paper
presents a hybrid reconstruction method that combines the `Gaussianization''
technique of Weinberg(1992) with the dynamical schemes of Nusser & Dekel(1992)
and Gramann(1993). We test the method on N-body simulations and on N-body mock
catalogs that mimic the depth and geometry of the Point Source Catalog Redshift
Survey and the Optical Redshift Survey. This method is more accurate than
Gaussianization or dynamical reconstruction alone. Matching the observed
morphology of clustering can limit the bias factor b, independent of Omega.
Matching the cluster velocity dispersions and z-space distortions of the
correlation function xi(s,mu) constrains the parameter beta=Omega^{0.6}/b.
Relative to linear or quasi-linear approximations, a fully non-linear
reconstruction makes more accurate predictions of xi(s,mu) for a given beta,
thus reducing the systematic biases of beta measurements and offering further
scope for breaking the degeneracy between Omega and b. It also circumvents the
cosmic variance noise that limits conventional analyses of xi(s,mu). It can
also improve the determination of Omega and b from joint analyses of redshift
& peculiar velocity surveys as it predicts the fully non-linear peculiar
velocity distribution at each point in z-space.Comment: 72 pages including 33 figures, submitted to Ap
Smoothly-varying hopping rates in driven flow with exclusion
We consider the one-dimensional totally asymmetric simple exclusion process
(TASEP) with position-dependent hopping rates. The problem is solved,in a mean
field/adiabatic approximation, for a general (smooth) form of spatial rate
variation. Numerical simulations of systems with hopping rates varying linearly
against position (constant rate gradient), for both periodic and open boundary
conditions, provide detailed confirmation of theoretical predictions,
concerning steady-state average density profiles and currents, as well as
open-system phase boundaries, to excellent numerical accuracy.Comment: RevTeX 4.1, 14 pages, 9 figures (published version
In pursuit of the dynamic optimality conjecture
In 1985, Sleator and Tarjan introduced the splay tree, a self-adjusting
binary search tree algorithm. Splay trees were conjectured to perform within a
constant factor as any offline rotation-based search tree algorithm on every
sufficiently long sequence---any binary search tree algorithm that has this
property is said to be dynamically optimal. However, currently neither splay
trees nor any other tree algorithm is known to be dynamically optimal. Here we
survey the progress that has been made in the almost thirty years since the
conjecture was first formulated, and present a binary search tree algorithm
that is dynamically optimal if any binary search tree algorithm is dynamically
optimal.Comment: Preliminary version of paper to appear in the Conference on Space
Efficient Data Structures, Streams and Algorithms to be held in August 2013
in honor of Ian Munro's 66th birthda
Supersonic aeroelastic instability results for a NASP-like wing model
An experimental study and an analytical study have been conducted to examine static divergence for hypersonic-vehicle wing models at supersonic conditions. A supersonic test in the Langley Unitary Plan Wind Tunnel facility was conducted for two wind-tunnel models. These models were nearly identical with the exception of airfoil shape. One model had a four-percent maximum thickness airfoil and the other model had an eight-percent maximum thickness airfoil. The wing models had low-aspect ratios and highly swept leading edges. The all-movable wing models were supported by a single-pivot mechanism along the wing root. For both of the wind-tunnel models, configuration changes could be made in the wing-pivot location along the wing root and in the wing-pivot pitch stiffness. Three divergence conditions were measured for the four-percent thick airfoil model in the Mach number range of 2.6 to 3.6 and one divergence condition was measured for the eight-percent thick airfoil model at a Mach number of 2.9. Analytical divergence calculations were made for comparison with experimental results and to evaluate the parametric effects of wing-pivot stiffness, wing-pivot location, and airfoil thickness variations. These analyses showed that decreasing airfoil thickness, moving the wing-pivot location upstream, or increasing the pitch-pivot stiffness have the beneficial effect of increasing the divergence dynamic pressures. The calculations predicted the trend of experimental divergence dynamic pressure with Mach number accurately; however, the calculations were approximately 25 percent conservative with respect to dynamic pressure
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