8,238 research outputs found
Brief Notice on T. H. Lewin’s Visit to the Arakan Hills in 1865-1866, edited by Michael W. Charney
This notice was originally published as “Diary of a Hill-Trip on the Borders of Arracan. By Lieutenant T. H. Lewis” in 1867. Edited by Michael W. Charney for the SOAS Bulletin of burma Research
Interface: Fringe Landscapes and Identity
An MFA thesis that weaves together: virtual landscapes, escapism, Theresa Hak Kyung Cha, utopia, family, and identity
A 2D systems approach to iterative learning control for discrete linear processes with zero Markov parameters
In this paper a new approach to iterative learning control for the practically relevant case of deterministic discrete linear plants with uniform rank greater than unity is developed. The analysis is undertaken in a 2D systems setting that, by using a strong form of stability for linear repetitive processes, allows simultaneous con-sideration of both trial-to-trial error convergence and along the trial performance, resulting in design algorithms that can be computed using Linear Matrix Inequalities (LMIs). Finally, the control laws are experimentally verified on a gantry robot that replicates a pick and place operation commonly found in a number of applications to which iterative learning control is applicable
Urban flooding in Britain:An approach to comparing ancient and contemporary flood exposure
Using modified UK Environment Agency Flood Estimation Handbook techniques, inundation extent and likely flood hydrographs for 0.1% probability annual return periods are compared for twelve Roman town sites in the UK, both at the present day and for simulated Roman catchment conditions. Eight of the study sites appear to have suffered minimal urban flood liability as occupied in the Roman period. The exceptions were Canterbury, York, Leicester, and Chichester. It is reasonable to expect flood characteristics to have changed subsequently in response to transformations in catchment land use, urban expansion, wetland reclamation, and floodway engineering. However, modelling results suggest limited differences in flood flows attributable to such factors. Greater present-day urban damage liability essentially results from floodplain urban extension. There are also contrasts between sites: those Roman towns lying on floodplains themselves, rather than on slightly elevated terraces (Canterbury, Chichester), are dominated by groundwater regimes with attenuated flood peaks. Taken together, these results suggest some Roman awareness of the actualities of urban flood liability at the time. Site sensitivity has not been carried forward as urban expansion has flourished, especially from the nineteenth century with suburban and industrial expansion. The straightforward mapping approach here suggested should in future take account of multiple century-scale hydroclimatic changes, morphological river channel and floodplain transformations over similar time periods, and on-going improvements to inundation modelling
Evolution of Massive Haloes in non-Gaussian Scenarios
We have performed high-resolution cosmological N-body simulations of a
concordance LCDM model to study the evolution of virialized, dark matter haloes
in the presence of primordial non-Gaussianity. Following a standard procedure,
departures from Gaussianity are modeled through a quadratic Gaussian term in
the primordial gravitational potential, characterized by a dimensionless
non-linearity strength parameter f_NL. We find that the halo mass function and
its redshift evolution closely follow the analytic predictions of Matarrese et
al.(2000). The existence of precise analytic predictions makes the observation
of rare, massive objects at large redshift an even more attractive test to
detect primordial non-Gaussian features in the large scale structure of the
universe.Comment: 7 pages,3 figures, submitted to MNRA
Performance and Fundamental Processes at Low Energy in a Two-Phase Liquid Xenon Dark Matter Detector
We extend the study of the performance of a prototype two-phase liquid xenon
WIMP dark matter detector to recoil energies below 20 keV. We demonstrate a new
method for obtaining the best estimate of the energies of events using a
calibrated sum of charge and light signals and introduce the corresponding
discrimination parameter, giving its mean value at 4 kV/cm for electron and
nuclear recoils up to 300 and 100 keV, respectively. We show that fluctuations
in recombination limit discrimination for most energies, and reveal an
improvement in discrimination below 20 keV due to a surprising increase in
ionization yield for low energy electron recoils. This improvement is crucial
for a high-sensitivity dark matter search.Comment: 4 pages, 6 figures, submitted to DM06 conference proceedings in Nucl
Phys
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