2,150 research outputs found
Sighted: an overview
This article is an examination of audience responses to Sighted, two solo dance performances presented individually and simultaneously. The work was presented at venues related to different disciplines. Audience members, who numbered up to 20 and who were free to choose where to stand or move around the space and how to behave, were invited immediately following the performance to write down their responses. This was in order to elicit direct and undigested thoughts before conversation or dialogue has started. These, together with interviews with the dancers, form the basis for this research, which looks at the nature of venues and audiences and to what extent privately felt and communally understood audience commentary can correlate
Unsteady turbulent buoyant plumes
We model the unsteady evolution of turbulent buoyant plumes following
temporal changes to the source conditions. The integral model is derived from
radial integration of the governing equations expressing the conservation of
mass, axial momentum and buoyancy. The non-uniform radial profiles of the axial
velocity and density deficit in the plume are explicitly described by shape
factors in the integral equations; the commonly-assumed top-hat profiles lead
to shape factors equal to unity. The resultant model is hyperbolic when the
momentum shape factor, determined from the radial profile of the mean axial
velocity, differs from unity. The solutions of the model when source conditions
are maintained at constant values retain the form of the well-established
steady plume solutions. We demonstrate that the inclusion of a momentum shape
factor that differs from unity leads to a well-posed integral model. Therefore,
our model does not exhibit the mathematical pathologies that appear in
previously proposed unsteady integral models of turbulent plumes. A stability
threshold for the value of the shape factor is identified, resulting in a range
of its values where the amplitude of small perturbations to the steady
solutions decay with distance from the source. The hyperbolic character of the
system allows the formation of discontinuities in the fields describing the
plume properties during the unsteady evolution. We compute numerical solutions
to illustrate the transient development following an abrupt change in the
source conditions. The adjustment to the new source conditions occurs through
the propagation of a pulse of fluid through the plume. The dynamics of this
pulse are described by a similarity solution and, by constructing this new
similarity solution, we identify three regimes in which the evolution of the
transient pulse following adjustment of the source qualitatively differ.Comment: 41 pages, 16 figures, under consideration for publication in Journal
of Fluid Mechanic
Tree-ring analysis of winter climate variability and ENSO in Mediterranean California
The feasibility of using tree-ring data as a proxy for regional precipitation and ENSO events in the Mediterranean region of California is explored. A transect of
moisture-sensitive tree-ring sites, extending from southwestern to northcentral California, documents regional patterns of winter precipitation and replicates the regional response to ENSO events in the 20th century. Proxy records of ENSO were used with the tree-ring data to examine precipitation/ENSO patterns in the 18 and 19th centuries. Results suggest some temporal and spatial variability in the regional precipitation response to ENSO over the last three centuries
The Computational Power of Minkowski Spacetime
The Lorentzian length of a timelike curve connecting both endpoints of a
classical computation is a function of the path taken through Minkowski
spacetime. The associated runtime difference is due to time-dilation: the
phenomenon whereby an observer finds that another's physically identical ideal
clock has ticked at a different rate than their own clock. Using ideas
appearing in the framework of computational complexity theory, time-dilation is
quantified as an algorithmic resource by relating relativistic energy to an
th order polynomial time reduction at the completion of an observer's
journey. These results enable a comparison between the optimal quadratic
\emph{Grover speedup} from quantum computing and an speedup using
classical computers and relativistic effects. The goal is not to propose a
practical model of computation, but to probe the ultimate limits physics places
on computation.Comment: 6 pages, LaTeX, feedback welcom
The Political Cost of Public-Private Partnerships: Theory and Evidence from Colombian Infrastructure Development
Infrastructure public–private partnerships (PPPs) eschew traditional public management to provide distributive goods worldwide. Yet, in Colombia, the context of our study, both the promise of and voters' experience with PPPs hinder incumbent parties in elections when theories of distributive politics expect otherwise. We argue that negative experiences with PPPs introduce a sociotropic turn in individual voting: bad experience crowds out the possibility that promising a new project will improve a voter's own welfare. Studying what are, to our knowledge, all 109 Colombian PPP projects between 1998 and 2014, and over 8,700 individual survey responses, our evidence shows that vote intention for the incumbent executive or his party decreases as experience with more PPPs in respondents' districts increases. Our analysis and results introduce an important agenda for research into the political significance of these legacies of new public management
- …