25,053 research outputs found
Computer-Aided System for Wind Turbine Data Analysis
Context: The current work on wind turbine failure detection focuses on researching suitable signal processing algorithms and developing efficient diagnosis algorithms. The laboratory research would involve large and complex data, and it can be a daunting task.
Aims: To develop a Computer-Aided system for assisting experts to conduct an efficient laboratory research on wind turbine data analysis. System is expected to provide data visualization, data manipulation, massive data processing and wind turbine failure detection.
Method: 50G off-line SCADA data and 4 confident diagnosis algorithms were used in this project. Apart from the instructions from supervisor, this project also gained help from two experts from Engineering Department. Java and Microsoft SQL database were used to develop the system.
Results: Data visualization provided 6 different charting solutions and together with robust user interactions. 4 failure diagnosis solutions and data manipulations were provided in the system. In addition, dedicated database server and Matlab API with Java RMI were used to resolve the massive data processing problem.
Conclusions: Almost all of the deliverables were completed. Friendly GUI and useful functionalities make user feel more comfortable. The final product does enable experts to conduct an efficient laboratory research. The end of this project also gave some potential extensions of the system
MC-TESTER: a universal tool for comparisons of Monte Carlo predictions for particle decays in high energy physics
Theoretical predictions in high energy physics are routinely provided in the
form of Monte Carlo generators. Comparisons of predictions from different
programs and/or different initialization set-ups are often necessary. MC-TESTER
can be used for such tests of decays of intermediate states (particles or
resonances) in a semi-automated way. Our test consists of two steps. Different
Monte Carlo programs are run; events with decays of a chosen particle are
searched, decay trees are analysed and appropriate information is stored. Then,
at the analysis step, a list of all found decay modes is defined and branching
ratios are calculated for both runs. Histograms of all scalar Lorentz-invariant
masses constructed from the decay products are plotted and compared for each
decay mode found in both runs. For each plot a measure of the difference of the
distributions is calculated and its maximal value over all histograms for each
decay channel is printed in a summary table. As an example of MC-TESTER
application, we include a test with the tau lepton decay Monte Carlo
generators, TAUOLA and PYTHIA. The HEPEVT (or LUJETS) common block is used as
exclusive source of information on the generated events.Comment: Version as published in Computer Physics Communications, 157(2004) 1,
pp 39-6
Boundary Shear Stress Distribution in Smooth and Rough Open Channel Flow
Boundary shear distribution in open channel flow is a crucial issue for river engineer and researchers working in this area.An experimental investigation has been carried out to measure the boundary shear stress distribution along the wetted perimeter of the smooth and rough channel using piston tube technique the accuracy of the method has been compared and checked with another convention method,NDM, VDM,MPM,Velocity Profile Method and energy gradient approach.The boundary shear along the bed and wall of the channel are different for different flow depth and for different roughness conditions.The percentage of boundary shear carried by the wall and bed has been analysed and found to depends on upon non-dimensional geometry and hydraulic parameters such as Aspect ratio,Reynolds number and Froude’s number.A multi linear regression model has been applied to predict the boundary shear distribution for bed.The equation is useful to calculate the roughness coefficient (friction factor) of the wall and bed of the channel separately,which further determines the composite roughness of the open channel flow accuracy.The methodology has been applied successfully to calculate the stage discharge relationship of the open channel flow.The methodology has been validated against other experimental data, other researcher’s models and Natural Rive
Finite Element Simulation of Dense Wire Packings
A finite element program is presented to simulate the process of packing and
coiling elastic wires in two- and three-dimensional confining cavities. The
wire is represented by third order beam elements and embedded into a
corotational formulation to capture the geometric nonlinearity resulting from
large rotations and deformations. The hyperbolic equations of motion are
integrated in time using two different integration methods from the Newmark
family: an implicit iterative Newton-Raphson line search solver, and an
explicit predictor-corrector scheme, both with adaptive time stepping. These
two approaches reveal fundamentally different suitability for the problem of
strongly self-interacting bodies found in densely packed cavities. Generalizing
the spherical confinement symmetry investigated in recent studies, the packing
of a wire in hard ellipsoidal cavities is simulated in the frictionless elastic
limit. Evidence is given that packings in oblate spheroids and scalene
ellipsoids are energetically preferred to spheres.Comment: 17 pages, 7 figures, 1 tabl
PHASE, a Monte Carlo event generator for six-fermion physics at the LHC
PHASE is a new event generator dedicated to the study of Standard Model
processes with six fermions in the final state at the LHC. The code is intended
for analyses of vector boson scattering, Higgs search, three gauge boson
production, and top physics. This first version of the program describes final
states characterized by the presence of one neutrino, , at
O(). PHASE is based on a new iterative-adaptive multichannel
technique, and employs exact leading order matrix elements. The code can
generate unweighted events for any subset of all available final states. The
produced parton-level events carry full information on their colour and flavour
structure, enabling the evolution of the partons into fully hadronised final
states. An interface to hadronization packages is provided via the Les Houches
Protocol.Comment: 27 pages, Latex, 6 figure
Results from 730 kg days of the CRESST-II Dark Matter Search
The CRESST-II cryogenic Dark Matter search, aiming at detection of WIMPs via
elastic scattering off nuclei in CaWO crystals, completed 730 kg days of
data taking in 2011. We present the data collected with eight detector modules,
each with a two-channel readout; one for a phonon signal and the other for
coincidently produced scintillation light. The former provides a precise
measure of the energy deposited by an interaction, and the ratio of
scintillation light to deposited energy can be used to discriminate different
types of interacting particles and thus to distinguish possible signal events
from the dominant backgrounds. Sixty-seven events are found in the acceptance
region where a WIMP signal in the form of low energy nuclear recoils would be
expected. We estimate background contributions to this observation from four
sources: 1) "leakage" from the e/\gamma-band 2) "leakage" from the
\alpha-particle band 3) neutrons and 4) Pb-206 recoils from Po-210 decay. Using
a maximum likelihood analysis, we find, at a high statistical significance,
that these sources alone are not sufficient to explain the data. The addition
of a signal due to scattering of relatively light WIMPs could account for this
discrepancy, and we determine the associated WIMP parameters.Comment: 17 pages, 13 figure
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