1,976 research outputs found
Data-driven Flood Emulation: Speeding up Urban Flood Predictions by Deep Convolutional Neural Networks
Computational complexity has been the bottleneck of applying physically-based
simulations on large urban areas with high spatial resolution for efficient and
systematic flooding analyses and risk assessments. To address this issue of
long computational time, this paper proposes that the prediction of maximum
water depth rasters can be considered as an image-to-image translation problem
where the results are generated from input elevation rasters using the
information learned from data rather than by conducting simulations, which can
significantly accelerate the prediction process. The proposed approach was
implemented by a deep convolutional neural network trained on flood simulation
data of 18 designed hyetographs on three selected catchments. Multiple tests
with both designed and real rainfall events were performed and the results show
that the flood predictions by neural network uses only 0.5 % of time comparing
with physically-based approaches, with promising accuracy and ability of
generalizations. The proposed neural network can also potentially be applied to
different but relevant problems including flood predictions for urban layout
planning
Reconstruction of Quark Mass Matrices with Weak Basis Texture Zeroes from Experimental Input
All quark mass matrices with texture zeroes obtained through weak basis
transformations are confronted with the experimental data. The reconstruction
of the quark mass matrices M_u and M_d at the electroweak scale is performed in
a weak basis where the matrices are Hermitian and have a maximum of three
vanishing elements. The same procedure is also accomplished for the Yukawa
coupling matrices at the grand unification scale in the context of the Standard
Model and its minimal supersymmetric extension as well as of the two Higgs
doublet model. The analysis of all viable power structures on the quark Yukawa
coupling matrices that could naturally appear from a Froggatt-Nielsen mechanism
is also presented.Comment: RevTeX4, 3 tables, 21 pages; misprints corrected and one reference
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Software-defined networking: guidelines for experimentation and validation in large-scale real world scenarios
Part 1: IIVC WorkshopInternational audienceThis article thoroughly details large-scale real world experiments using Software-Defined Networking in the testbed setup. More precisely, it provides a description of the foundation technology behind these experiments, which in turn is focused around OpenFlow and on the OFELIA testbed. In this testbed preliminary experiments were performed in order to tune up settings and procedures, analysing the encountered problems and their respective solutions. A methodology consisting of five large-scale experiments is proposed in order to properly validate and improve the evaluation techniques used in OpenFlow scenarios
Observations of Reconnection Flows in a Flare on the Solar Disk
Magnetic reconnection is a well-accepted part of the theory of solar eruptive
events, though the evidence is still circumstantial. Intrinsic to the
reconnection picture of a solar eruptive event, particularly in the standard
model for two-ribbon flares ("CSHKP" model), are an advective flow of
magnetized plasma into the reconnection region, expansion of field above the
reconnection region as a flux rope erupts, retraction of heated
post-reconnection loops, and downflows of cooling plasma along those loops. We
report on a unique set of SDO/AIA imaging and Hinode/EIS spectroscopic
observations of the disk flare SOL2016-03-23T03:54 in which all four flows are
present simultaneously. This includes spectroscopic evidence for a plasma
upflow in association with large-scale expanding closed inflow field. The
reconnection inflows are symmetric, and consistent with fast reconnection, and
the post-reconnection loops show a clear cooling and deceleration as they
retract. Observations of coronal reconnection flows are still rare, and most
events are observed at the solar limb, obscured by complex foregrounds, making
their relationship to the flare ribbons, cusp field and arcades formed in the
lower atmosphere difficult to interpret. The disk location and favorable
perspective of this event have removed these ambiguities giving a clear picture
of the reconnection dynamics.Comment: 9 pages, 5 figures, and 1 table. Accepted for publication in ApJ
A KINEMATIC ANALYSIS OF ROWING PERFORMANCE DURING A 2000M ERGOMETER TEST
The aim of this study was to investigate how force, velocity and power change during a maximum 2000m-rowing test, and to examine the relationship between 2-D joint kinematics and performance. Ten male rowers performed a 2000m test, which was analysed in five periods, considering also the mean final results. One-way ANOVA for repeated measures showed that force, velocity and power changed significantly along the 2000m test. Hip, and elbow joint kinematic parameters remained unchanged throughout the test but knee’s angular displacement and angular position at the catch, changed significantly during the 2000m test. A stepwise multiple regression analysis evidenced that the knee angular position at the catch is in relationship with time to finish the 2000m rowing and remained the single predictor of performance
Estoque e qualidade da matéria orgânica de um solo cultivado com cana-de-açúcar por longo tempo.
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