72 research outputs found
Prediction of impending drought scenarios based on surface and subsurface parameters in a selected region of tropical Queensland, Australia
Droughts occur in all climatic regions around the world costing a large expense to global economies. Reasonably accurate prediction of drought events helps water managers proper planning for utilization of limited water resources and distribution of available waters to different sectors and avoid catastrophic consequences. Therefore, a means to create a simplistic approach for forecasting drought conditions with easily accessible parameters is highly desirable. This study proposes and evaluates newly developed accurate prediction models utilizing various hydrologic, meteorological, and geohydrology parameters along with the use of Artificial Neural Network (ANN) models with various forecast lead times. The present study develops a multitude of forecasting models to predict drought indices such as the Standard Precipitation Index with a lead-time of up to 6 months, and the Soil Moisture Index with a lead-time of 3 months. Furthermore, prediction models with the capability of approximating surface and groundwater storage levels including the Ross River Dam level have been developed with relatively high accuracy with a lead-time of 3 months. The results obtained from these models were compared to current values, revealing that ANN based approach can be used as a simple and effective predictive model that can be utilized for prediction of different aspects of drought scenarios in a typical study area like Townsville, North Queensland, Australia which had suffered severe recent drought conditions for almost six recent years (2014 to early 2019)
Primary transitional cell carcinoma of bulbar urethra
Primary urethral carcinoma (UC) is a rare entity, and bulbar UCs of transitional cell origin are even rarer. Primary presentation as a scrotal abscess and urethrocutaneous fistula is rarely documented in UC patients. We present a case of a 66-year-old male presenting to emergency department with a scrotal abscess. Following blind incision and drainage, the urethral injury was suspected, and biopsy of suspicious lesion was taken from scrotum which came out to be invasive transitional cell carcinoma. A wide local excision of the tumor was done after workup. Hence, all patients with scrotal abscess and urethrocutaneous fistula should be investigated before performing any blind procedure
Groundwater level prediction using a multiple objective genetic algorithm-grey relational analysis based weighted ensemble of anfis models
Predicting groundwater levels is critical for ensuring sustainable use of an aquiferâs limited groundwater reserves and developing a useful groundwater abstraction management strategy. The purpose of this study was to assess the predictive accuracy and estimation capability of various models based on the Adaptive Neuro Fuzzy Inference System (ANFIS). These models included Differential Evolution-ANFIS (DE-ANFIS), Particle Swarm Optimization-ANFIS (PSO-ANFIS), and traditional Hybrid Algorithm tuned ANFIS (HA-ANFIS) for the one-and multi-week forward forecast of groundwater levels at three observation wells. Model-independent partial autocorrelation functions followed by frequentist lasso regression-based feature selection approaches were used to recognize appropriate input variables for the prediction models. The performances of the ANFIS models were evaluated using various statistical performance evaluation indexes. The results revealed that the optimized ANFIS models performed equally well in predicting one-week-ahead groundwater levels at the observation wells when a set of various performance evaluation indexes were used. For improving prediction accuracy, a weighted-average ensemble of ANFIS models was proposed, in which weights for the individual ANFIS models were calculated using a Multiple Objective Genetic Algorithm (MOGA). The MOGA accounts for a set of benefits (higher values indicate better model performance) and cost (smaller values indicate better model performance) performance indexes calculated on the test dataset. Grey relational analysis was used to select the best solution from a set of feasible solutions produced by a MOGA. A MOGA-based individual model ranking revealed the superiority of DE-ANFIS (weight = 0.827), HA-ANFIS (weight = 0.524), and HAANFIS (weight = 0.697) at observation wells GT8194046, GT8194048, and GT8194049, respectively. Shannonâs entropy-based decision theory was utilized to rank the ensemble and individual ANFIS models using a set of performance indexes. The ranking result indicated that the ensemble model outperformed all individual models at all observation wells (ranking value = 0.987, 0.985, and 0.995 at observation wells GT8194046, GT8194048, and GT8194049, respectively). The worst performers were PSO-ANFIS (ranking value = 0.845), PSO-ANFIS (ranking value = 0.819), and DE-ANFIS (ranking value = 0.900) at observation wells GT8194046, GT8194048, and GT8194049, respectively. The generalization capability of the proposed ensemble modelling approach was evaluated for forecasting 2-, 4-, 6-, and 8-weeks ahead groundwater levels using data from GT8194046. The evaluation results confirmed the useability of the ensemble modelling for forecasting groundwater levels at higher forecasting horizons. The study demonstrated that the ensemble approach may be successfully used to predict multi-week-ahead groundwater levels, utilizing previous lagged groundwater levels as inputs
Hydrochemistry, water quality and land use signatures in an ephemeral tidal river : implications in water management in the southwestern coastal region of Bangladesh
Despite its complexity and importance in managing water resources in populous deltas, especially in tidal areas, literatures on tidal rivers and their land use linkage in connection to water quality and pollution are rare. Such information is of prior need for Integrated Water Resource Management in water scarce and climate change vulnerable regions, such as the southwestern coast of Bangladesh. Using water quality indices and multivariate analysis, we present here the land use signatures of a dying tidal river due to anthropogenic perturbation. Correlation matrix, hierarchical cluster analysis, factor analysis, and bio-geo-chemical fingerprints were used to quantify the hydro-chemical and anthropogenic processes and identify factors influencing the ionic concentrations. The results show remarkable spatial and temporal variations (p <0.05) in water quality parameters. The lowest solute concentrations are observed at the mid reach of the stream where the agricultural and urban wastewater mix. Agricultural sites show higher concentration of DO, Na+ and K+ reflecting the effects of tidal spill-over and shrimp wastewater effluents nearby. Higher level of Salinity, EC, Cl-, HCO3 (-), NO3 (-), PO4 (3-) and TSS characterize the urban sites indicating a signature of land use dominated by direct discharge of household organic waste into the waters. The spatial variation in overall water quality suggests a periodic enhancement of quality especially for irrigation and non-drinking purposes during monsoon and post-monsoon, indicating significant influence of amount of rainfall in the basin. We recommend that, given the recent trend of increasing precipitation and ground water table decrease, such dying tidal river basins may serve as excellent surface water reservoir to supplement quality water supply to the region.Peer reviewe
Signals of anomaly mediated supersymmetry breaking in an e^- gamma collider
We study the signatures of minimal anomaly mediated supersymmetry breaking in
an e^- gamma collider. We demonstrate that the associated production of a
sneutrino with the lightest chargino leads to a substantially large signal
size. The background is negligibly small, though. Even more interestingly, a
measurement of the fundamental supersymmetry breaking parameters could be
possible.Comment: 25 pages, LaTex, 7 PS figures and 1 table (included
Higgs production in association with top quark pair at e+e- colliders in theories of higher dimensional gravity
The models of large extra compact dimensions, as suggested by Arkani-Hamed,
Dimopoulos and Dvali, predict exciting phenomenological consequences with
gravitational interactions becoming strong at the TeV scale. Such theories can
be tested at the existing and future colliders. In this paper, we study the
contribution of virtual Kaluza-Klein excitations in the process at future linear collider (NLC). We find that the virtual exchange
KK gravitons can modify the cross-section
significantly from its Standard Model value and will allow the effective string
scale to be probed up to 7.9 TeV.Comment: 10 pages, Latex, 4 postscript figure
Flavor and CP violating Z exchange and the rate asymmetry in B --> phi K_S
Recent measurements of time dependent CP asymmetry in B --> phi K_S, if
confirmed, would indicate a new source of CP violation. We examine flavor
violating tree-level Z currents in models with extra down-type quark singlets
that arise naturally in string compactified gauge groups like E_6. We evaluate
the new operators at the scale mu = m_b in NLO, and using QCD improved
factorization to describe B --> phi K_S, find the allowed range of parameters
for rho and psi, the magnitude and phase of the flavor violating parameter
U_{bs}. This allowed range does satisfy the constraint from flavor changing
process b --> s l+ l- . However, further improvement in measurement of these
rates could severely constrain the model.Comment: 15 pages, Latex, 2 postscript figures. Sections 2 and 3 are
reordered. More references are added. Version to be published in PL
A study of single sneutrino production in association with fermion pairs at polarised photon colliders
We investigate single sneutrino production in the context of
R-parity-violating Supersymmetry at future linear colliders. The
sneutrino is produced in association with fermion pairs and it is shown that
its decays into two further fermions will lead to a clean signal. We also
discuss possible backgrounds and the effects of beam polarisation.Comment: 31 pages, LaTeX, 10 postscript figures. Title has been modified. Two
new figures and one appendix added. Detailed SM background estimations were
made. A new reference added. Version to appear in PR
A fourth generation, anomalous like-sign dimuon charge asymmetry and the LHC
A fourth chiral generation, with in the range GeV and a moderate value of the CP-violating phase can explain the
anomalous like-sign dimuon charge asymmetry observed recently by the D0
collaboration. The required parameters are found to be consistent with
constraints from other and decays. The presence of such quarks, apart
from being detectable in the early stages of the LHC, would also have important
consequences in the electroweak symmetry breaking sector.Comment: 18 pages, 9 figures, Figure 1 is modified, more discussions are added
in section 2. new references adde
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