A hybrid generalised linear and Levenberg-Marquardt artificial neural network approach for downscaling future rainfall in North Western England

This paper describes a novel technique for downscaling daily rainfall which uses a combination of a generalised linear model (GLM) and artificial neural network (ANN) to downscale rainfall. A two-stage process is applied, an occurrence process which uses the GLM model and an amount process which uses an ANN model trained with a Levenberg–Marquardt approach. The GLM-ANN was compared with other three downscaling models, the traditional neural network (ANN), multiple linear regression (MLR) and Poisson regression (PR). The models are applied for downscaling daily rainfall at three locations in the North West of England during the winter and summer. Model performances with respect to reproduction of various statistics such as correlation coefficient, autocorrelation, root mean square errors (RMSE), standard deviation and the mean rainfall are examined. It is found that the GLM-ANN model performs better than the other three models in reproducing most daily rainfall statistics, with slight difficulties in predicting extremes rainfall event in summer. The GLM-ANN model is then used to project future rainfall at the three locations employing three different general circulation models (GCMs) for SRES scenarios A2 and B2. The study projects significant increases in mean daily rainfall at most locations for winter and decreases in summe

Application of the stochastic model for temporal rainfall disaggregation for hydrological studies in north western England

Assessment of climate change on any hydrological system requires higher temporal resolution at hourly or less in terms of time-scale. This paper implements the Bartlett-Lewis Rectangular Pulses (BLRP) model coupled with a proportional adjusting procedure to disaggregate daily rainfall to hourly rainfall in order to demonstrate the reliability of this method. Three stations in NorthWestern England have been selected that represent different climates in the region. Parameters estimation of the BLRP model has been performed under different levels of hourly rainfall aggregation for a combination of rainfall statistics. The Hyetos model, which applies BLRP, reproduced standard statistics such as mean, variance, Lag -1, autocorrelation as well as dry proportions. Moreover, the model was proven to have the capability to disaggregate the rainfall extremes. The fitted BLRP model could then be used to disaggregate future daily rainfall in order to investigate the climate change impact of different rainfall intensities

Application of the UKCP09 WG Outputs to Assess Performance of Combined Sewers System in a Changing Climate

In many parts of the world old sewer systems have been designed without consideration for change in climate, so probabilities and risks of sewer surcharge and flooding are elevated due to increase in extreme rainfall events as a consequence of global warming. The current paper is aiming to assess how the climate change on interannual to multidecadal timescale (2020s, 2050s, 2080s) will affect design standards of waste water networks due to the presumed increase in rainfall intensity and frequency in the Northwest of England area (selected site). Design storms have been analysed for future rainfall obtained from the UK Climate Projection version 2009 (UKCP09) weather generator, which was applied to the existing urban drainage system to check the level of service in winter and summer seasons. Two emission scenarios (SRES) have been adopted to simulate the greenhouse gas concentration; high scenario (A1FI) and low scenario (B1). Results indicate that the impact of increase in the deign storm of the system in winter lead to a potential of increase flood volume from manholes and intern basements at risk of flooding with the worst condition associated with 24 hours storm in 2080s. Moreover, when this design storm depth increased by only 15%, the corresponding flood volume increase by 40%, this indicates that the relation between the cause of flooding and its consequences is non-linear. Summer season has an opposite picture and flood volume is projected to decrease with the increase in the storm duration causing low risk. Considering climate change in this study caused most of urban drainage models runs to be very slow with some interruption in the simulation due to the inflation in some parameters, so cautious should be taken

“Analysis of The Lateral Response of A Reinforced Concrete Pile Penetrated In Sand Soil Using Finite Element”

Pile foundations are slender elements, underneath a major structure, frequently used for many decades as load carrying and load transferring systems from shallow inadequate subsurface soil layers to deep and stiff bearing strata with high degree of efficiency. Moreover, the laterally loaded response of concrete reinforced piles penetrated in sandy soil is normally analysed using Winkler Model (beam on elastic foundation), in which the sand-pile-sand interaction is simulated by highly nonlinear p–y curves. The present study presents the result of numerical analyses of the behaviour of reinforced concrete squared model piles (400 mm in diameter) with embedment depth-to-diameter ratio (L/d) of (20)penetrated in a calibrated chamber of pre prepared dense sand relative density

“Simulation of Soil Pile Interaction of Steel Batter Piles Penetrated in Sandy Soil subjected to Pull-out Loads”

Super structures like offshore platforms, tall buildings, transition towers, skyscrapers and bridges are normally designed to resist compression, uplift and lateral forces from wind waves, negative skin friction, ship impact and other applied loads. Better understanding and the precise simulation of the response of batter piles under the action of independent uplift loads is a vital topic and an area of active research in the field of geotechnical engineering. This paper investigates the use of finite element code (FEC) to examine the behaviour of model batter piles penetrated in dense sand, subjected to pull-out pressure by means of numerical modelling. The concept of the Winkler Model (beam on elastic foundation) has been used in which the interaction between the pile embedded depth and adjacent soil in the bearing zone is simulated by nonlinea

Nonlinearity-assisted quantum tunneling in a matter-wave interferometer

We investigate the {\em nonlinearity-assisted quantum tunneling} and formation of nonlinear collective excitations in a matter-wave interferometer, which is realised by the adiabatic transformation of a double-well potential into a single-well harmonic trap. In contrast to the linear quantum tunneling induced by the crossing (or avoided crossing) of neighbouring energy levels, the quantum tunneling between different nonlinear eigenstates is assisted by the nonlinear mean-field interaction. When the barrier between the wells decreases, the mean-field interaction aids quantum tunneling between the ground and excited nonlinear eigenstates. The resulting {\em non-adiabatic evolution} depends on the input states. The tunneling process leads to the generation of dark solitons, and the number of the generated dark solitons is highly sensitive to the matter-wave nonlinearity. The results of the numerical simulations of the matter-wave dynamics are successfully interpreted with a coupled-mode theory for multiple nonlinear eigenstates.Comment: 11 pages, 6 figures, accept for publication in J. Phys.

T1T_1- and T2T_2-spin relaxation time limitations of phosphorous donor electrons near crystalline silicon to silicon dioxide interface defects

A study of donor electron spins and spin--dependent electronic transitions involving phosphorous ($^{31}$P) atoms in proximity of the (111) oriented crystalline silicon (c-Si) to silicon dioxide (SiO$_{2}$) interface is presented for [$^{31}$P] = 10$^{15}$ $\mathrm{cm}^{-3}$ and [$^{31}$P] = 10$^{16}$ $\mathrm{cm}^{-3}$ at about liquid $^4$He temperatures ($T = 5$ $\mathrm{K} - 15$ $\mathrm{K}$). Using pulsed electrically detected magnetic resonance (pEDMR), spin--dependent transitions between the \Phos donor state and two distinguishable interface states are observed, namely (i) \Pb centers which can be identified by their characteristic anisotropy and (ii) a more isotropic center which is attributed to E$^\prime$ defects of the \sio bulk close to the interface. Correlation measurements of the dynamics of spin--dependent recombination confirm that previously proposed transitions between \Phos and the interface defects take place. The influence of these electronic near--interface transitions on the \Phos donor spin coherence time $T_2$ as well as the donor spin--lattice relaxation time $T_1$ is then investigated by comparison of spin Hahn--echo decay measurements obtained from conventional bulk sensitive pulsed electron paramagnetic resonance and surface sensitive pEDMR, as well as surface sensitive electrically detected inversion recovery experiments. The measurements reveal that both $T_2$ and $T_1$ of \Phos donor electrons spins in proximity of energetically lower interface states at $T\leq 13$ K are reduced by several orders of magnitude

Assessment of Water Harvesting System for a Smart Building Considering Climate Change

With climate change now a reality rather than speculated possibility, the future change of rainfall pattern will affect the demand for potable water. Forth coming regulatory changes will mean that over 90% of UK homes will have their water usage metered, making consumers more and more aware of how expensive the commodity of "common or garden" water has become. In this paper the design of different rainwater harvesting systems (RWH) is evaluated for three residential properties of different roof areas. The design considered climate change effect and change in future rainfall for three periods 2020s, 2050s and 2080s under the high (AIFI) and low (B1) SRES scenarios in NW of England. The RWH systems were shown to fulfill between 25% and 85% of WC, washing machine and outdoor use demand making the system more valuable as a sustainable solution

Mechanism, dynamics, and biological existence of multistability in a large class of bursting neurons

Multistability, the coexistence of multiple attractors in a dynamical system, is explored in bursting nerve cells. A modeling study is performed to show that a large class of bursting systems, as defined by a shared topology when represented as dynamical systems, is inherently suited to support multistability. We derive the bifurcation structure and parametric trends leading to multistability in these systems. Evidence for the existence of multirhythmic behavior in neurons of the aquatic mollusc Aplysia californica that is consistent with our proposed mechanism is presented. Although these experimental results are preliminary, they indicate that single neurons may be capable of dynamically storing information for longer time scales than typically attributed to nonsynaptic mechanisms.Comment: 24 pages, 8 figure

A Role for the Vacuolating Cytotoxin, VacA, in Colonization and Helicobacter pylori-Induced Metaplasia in the Stomach

Carriage of Helicobacter pylori strains producing more active (s1/i1) forms of VacA is strongly associated with gas-tric adenocarcinoma. To our knowledge, we are the first to determine effects of different polymorphic forms of VacA on inflammation and metaplasia in the mouse stomach. Bacteria producing the less active s2/i2 form of VacA colonized mice more efficiently than mutants null for VacA or producing more active forms of it, providing the first evidence of a positive role for the minimally active s2/i2 toxin. Strains producing more active toxin forms induced more severe and extensive metaplasia and in flammation in the mouse stomach than strains producing weakly active (s2/i2) toxin. We also examined the association in humans, controlling for cag PAI status. In human gastric biopsy specimens, the vacA i1 allele was strongly associated with precancerous intestinal metaplasia, with almost complete absence of intestinal metaplasia in subjects infected with i2-type strains, even in a vacA s1, cagA+ background