3,474 research outputs found
VISJET & VISFLOOD: Software for environment hydraulic modeling & visualization
We present two general interactive PC-based modeling and visualization software systems developed for
the study of two types of environmental water flows: buoyant jet mixing and urban drainage problems.
VISJET (http://www.aoe-water.hku.hk/visjet) is arguably the most robust software with advanced
graphics for the prediction of mixing and transport of effluent discharges into a stratified crossflow. The
prediction engine is a Lagrangian model for buoyant jets with three-dimensional trajectories, and is based
on extensive basic experiments and turbulence model calculations. It can be used in outfall design and
environmental impact assessment, and as an educational or training tool. VISFLOOD
(http://www.aoe-water.hku.hk/visflood) is based on the numerical solution of the Saint-Venant equations,
and caters for the simulation of unsteady flood propagation in urban drainage systems. Both software
systems are fully interactive with data interrogation; the 3D visualization is fully integrated with the
model engine, and enables the user to appreciate the context of the problem in a most effective way. Both
models have been well-validated against laboratory and field data, and have been applied to many actual
engineering projects. This software product is an outcome of a grant by the Hong Kong Innovation and
Technology Fund (ITF).published_or_final_versio
FSL-BM: Fuzzy Supervised Learning with Binary Meta-Feature for Classification
This paper introduces a novel real-time Fuzzy Supervised Learning with Binary
Meta-Feature (FSL-BM) for big data classification task. The study of real-time
algorithms addresses several major concerns, which are namely: accuracy, memory
consumption, and ability to stretch assumptions and time complexity. Attaining
a fast computational model providing fuzzy logic and supervised learning is one
of the main challenges in the machine learning. In this research paper, we
present FSL-BM algorithm as an efficient solution of supervised learning with
fuzzy logic processing using binary meta-feature representation using Hamming
Distance and Hash function to relax assumptions. While many studies focused on
reducing time complexity and increasing accuracy during the last decade, the
novel contribution of this proposed solution comes through integration of
Hamming Distance, Hash function, binary meta-features, binary classification to
provide real time supervised method. Hash Tables (HT) component gives a fast
access to existing indices; and therefore, the generation of new indices in a
constant time complexity, which supersedes existing fuzzy supervised algorithms
with better or comparable results. To summarize, the main contribution of this
technique for real-time Fuzzy Supervised Learning is to represent hypothesis
through binary input as meta-feature space and creating the Fuzzy Supervised
Hash table to train and validate model.Comment: FICC201
Effects of heavy modes on vacuum stability in supersymmetric theories
We study the effects induced by heavy fields on the masses of light fields in
supersymmetric theories, under the assumption that the heavy mass scale is much
higher than the supersymmetry breaking scale. We show that the square-masses of
light scalar fields can get two different types of significant corrections when
a heavy multiplet is integrated out. The first is an indirect level-repulsion
effect, which may arise from heavy chiral multiplets and is always negative.
The second is a direct coupling contribution, which may arise from heavy vector
multiplets and can have any sign. We then apply these results to the sGoldstino
mass and study the implications for the vacuum metastability condition. We find
that the correction from heavy chiral multiplets is always negative and tends
to compromise vacuum metastability, whereas the contribution from heavy vector
multiplets is always positive and tends on the contrary to reinforce it. These
two effects are controlled respectively by Yukawa couplings and gauge charges,
which mix one heavy and two light fields respectively in the superpotential and
the Kahler potential. Finally we also comment on similar effects induced in
soft scalar masses when the heavy multiplets couple both to the visible and the
hidden sector.Comment: LaTex, 24 pages, no figures; v2 some comments and references adde
The singlet scalar as FIMP dark matter
The singlet scalar model is a minimal extension of the Standard Model that
can explain the dark matter. We point out that in this model the dark matter
constraint can be satisfied not only in the already considered WIMP regime but
also, for much smaller couplings, in the Feebly Interacting Massive Particle
(FIMP) regime. In it, dark matter particles are slowly produced in the early
Universe but are never abundant enough to reach thermal equilibrium or
annihilate among themselves. This alternative framework is as simple and
predictive as the WIMP scenario but it gives rise to a completely different
dark matter phenomenology. After reviewing the calculation of the dark matter
relic density in the FIMP regime, we study in detail the evolution of the dark
matter abundance in the early Universe and the predicted relic density as a
function of the parameters of the model. A new dark matter compatible region of
the singlet model is identified, featuring couplings of order 10^-11 to 10^-12
for singlet masses in the GeV to TeV range. As a consequence, no signals at
direct or indirect detection experiments are expected. The relevance of this
new viable region for the correct interpretation of recent experimental bounds
is emphasized.Comment: 12 pages, 6 figure
Mixed Mediation of Supersymmetry Breaking with Anomalous U(1) Gauge Symmetry
Models with anomalous U(1) gauge symmetry contain various superfields which
can have nonzero supersymmetry breaking auxiliary components providing the
origin of soft terms in the visible sector, e.g. the U(1) vector superfield,
the modulus or dilaton superfield implementing the Green-Schwarz anomaly
cancellation mechanism, U(1)-charged but standard model singlet matter
superfield required to cancel the Fayet-Iliopoulos term, and finally the
supergravity multiplet. We examine the relative strength between these
supersymmetry breaking components in a simple class of models, and find that
various different mixed mediations of supersymmetry breaking, involving the
modulus, gauge, anomaly and D-term mediations, can be realized depending upon
the characteristics of D-flat directions and how those D-flat directions are
stabilized with a vanishing cosmological constant. We identify two parameters
which represent such properties and thus characterize how the various
mediations are mixed. We also discuss the moduli stabilization and soft terms
in a variant of KKLT scenario, in which the visible sector K\"ahler modulus is
stabilized by the D-term potential of anomalous U(1) gauge symmetry.Comment: 30 pages, 5 figure
The mu problem and sneutrino inflation
We consider sneutrino inflation and post-inflation cosmology in the singlet
extension of the MSSM with approximate Peccei-Quinn(PQ) symmetry, assuming that
supersymmetry breaking is mediated by gauge interaction. The PQ symmetry is
broken by the intermediate-scale VEVs of two flaton fields, which are
determined by the interplay between radiative flaton soft masses and higher
order terms. Then, from the flaton VEVs, we obtain the correct mu term and the
right-handed(RH) neutrino masses for see-saw mechanism. We show that the RH
sneutrino with non-minimal gravity coupling drives inflation, thanks to the
same flaton coupling giving rise to the RH neutrino mass. After inflation,
extra vector-like states, that are responsible for the radiative breaking of
the PQ symmetry, results in thermal inflation with the flaton field, solving
the gravitino problem caused by high reheating temperature. Our model predicts
the spectral index to be n_s\simeq 0.96 due to the additional efoldings from
thermal inflation. We show that a right dark matter abundance comes from the
gravitino of 100 keV mass and a successful baryogenesis is possible via
Affleck-Dine leptogenesis.Comment: 27 pages, no figures, To appear in JHE
Does the `Higgs' have Spin Zero?
The Higgs boson is predicted to have spin zero. The ATLAS and CMS experiments
have recently reported of an excess of events with mass ~ 125 GeV that has some
of the characteristics expected for a Higgs boson. We address the questions
whether there is already any evidence that this excess has spin zero, and how
this possibility could be confirmed in the near future. The excess observed in
the gamma gamma final state could not have spin one, leaving zero and two as
open possibilities. We calculate the angular distribution of gamma gamma pairs
from the decays of a spin-two boson produced in gluon-gluon collisions, showing
that is unique and distinct from the spin-zero case. We also calculate the
distributions for lepton pairs that would be produced in the W W* decays of a
spin-two boson, which are very different from those in Higgs decays, and note
that the kinematics of the event selection used to produce the excess observed
in the W W* final state have reduced efficiency for spin two.Comment: 22 pages, 22 figures, Version accepted for publication in JHEP,
includes additional plots of dilepton mass distribution
Oral immunization of haemaggulutinin H5 expressed in plant endoplasmic reticulum with adjuvant saponin protects mice against highly pathogenic avian influenza A virus infection
Pandemics in poultry caused by the highly pathogenic avian influenza (HPAI) A virus occur too frequently globally, and there is growing concern about the HPAI A virus due to the possibility of a pandemic among humans. Thus, it is important to develop a vaccine against HPAI suitable for both humans and animals. Various approaches are underway to develop such vaccines. In particular, an edible vaccine would be a convenient way to vaccinate poultry because of the behaviour of the animals. However, an edible vaccine is still not available. In this study, we developed a strategy of effective vaccination of mice by the oral administration of transgenic Arabidopsis plants (HA-TG) expressing haemagglutinin (HA) in the endoplasmic reticulum (ER). Expression of HA in the ER resulted in its high-level accumulation, N-glycosylation, protection from proteolytic degradation and long-term stability. Oral administration of HA-TG with saponin elicited high levels of HA-specific systemic IgG and mucosal IgA responses in mice, which resulted in protection against a lethal influenza virus infection with attenuated inflammatory symptoms. Based on these results, we propose that oral administration of freeze-dried leaf powders from transgenic plants expressing HA in the ER together with saponin is an attractive strategy for vaccination against influenza A virus.X111411Ysciescopu
Concomitant CIS on TURBT does not impact oncological outcomes in patients treated with neoadjuvant or induction chemotherapy followed by radical cystectomy
© Springer-Verlag GmbH Germany, part of Springer Nature 2018Background: Cisplatin-based neoadjuvant chemotherapy (NAC) for muscle invasive bladder cancer improves all-cause and cancer specific survival. We aimed to evaluate whether the detection of carcinoma in situ (CIS) at the time of initial transurethral resection of bladder tumor (TURBT) has an oncological impact on the response to NAC prior to radical cystectomy. Patients and methods: Patients were identified retrospectively from 19 centers who received at least three cycles of NAC or induction chemotherapy for cT2-T4aN0-3M0 urothelial carcinoma of the bladder followed by radical cystectomy between 2000 and 2013. The primary and secondary outcomes were pathological response and overall survival, respectively. Multivariable analysis was performed to determine the independent predictive value of CIS on these outcomes. Results: Of 1213 patients included in the analysis, 21.8% had concomitant CIS. Baseline clinical and pathologic characteristics of the âCISâ versus âno-CISâ groups were similar. The pathological response did not differ between the two arms when response was defined as pT0N0 (17.9% with CIS vs 21.9% without CIS; p = 0.16) which may indicate that patients with CIS may be less sensitive to NAC or †pT1N0 (42.8% with CIS vs 37.8% without CIS; p = 0.15). On Cox regression model for overall survival for the cN0 cohort, the presence of CIS was not associated with survival (HR 0.86 (95% CI 0.63â1.18; p = 0.35). The presence of LVI (HR 1.41, 95% CI 1.01â1.96; p = 0.04), hydronephrosis (HR 1.63, 95% CI 1.23â2.16; p = 0.001) and use of chemotherapy other than ddMVAC (HR 0.57, 95% CI 0.34â0.94; p = 0.03) were associated with shorter overall survival. For the whole cohort, the presence of CIS was also not associated with survival (HR 1.05 (95% CI 0.82â1.35; p = 0.70). Conclusion: In this multicenter, real-world cohort, CIS status at TURBT did not affect pathologic response to neoadjuvant or induction chemotherapy. This study is limited by its retrospective nature as well as variability in chemotherapy regimens and surveillance regimens.Peer reviewedFinal Accepted Versio
A statistical downscaling framework for environmental mapping
In recent years, knowledge extraction from data has become increasingly popular, with many numerical forecasting models, mainly falling into two major categoriesâchemical transport models (CTMs) and conventional statistical methods. However, due to data and model variability, data-driven knowledge extraction from high-dimensional, multifaceted data in such applications require generalisations of global to regional or local conditions. Typically, generalisation is achieved via mapping global conditions to local ecosystems and human habitats which amounts to tracking and monitoring environmental dynamics in various geographical areas and their regional and global implications on human livelihood. Statistical downscaling techniques have been widely used to extract high-resolution information from regional-scale variables produced by CTMs in climate model. Conventional applications of these methods are predominantly dimensional reduction in nature, designed to reduce spatial dimension of gridded model outputs without loss of essential spatial information. Their downside is twofoldâcomplete dependence on unlabelled design matrix and reliance on underlying distributional assumptions. We propose a novel statistical downscaling framework for dealing with data and model variability. Its power derives from training and testing multiple models on multiple samples, narrowing down global environmental phenomena to regional discordance through dimensional reduction and visualisation. Hourly ground-level ozone observations were obtained from various environmental stations maintained by the US Environmental Protection Agency, covering the summer period (JuneâAugust 2005). Regional patterns of ozone are related to local observations via repeated runs and performance assessment of multiple versions of empirical orthogonal functions or principal components and principal fitted components via an algorithm with fully adaptable parameters. We demonstrate how the algorithm can be extended to weather-dependent and other applications with inherent data randomness and model variability via its built-in interdisciplinary computational power that connects data sources with end-users
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