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Modelling of monopile-footing foundation system for offshore structures
While monopiles have proven to be an economically sound foundation solution for wind turbines, especially in relatively shallow water, their installation in deeper water and in hard ground may require a more complex foundation design in order to satisfy the loading conditions. One approach is that foundation systems are developed which combine several foundation elements to create a âhybridâ system. In this way it is possible to develop a foundation system which is more efficient for the combination of vertical and lateral loads associated with wind turbines while maintaining the efficiency and simplicity of the design. Previous studies have reported the results of single gravity tests of the hybrid system where the benefits of adding the footing to the pile are illustrated. This paper presents experimental results on the performance of skirted and unskirted monopile-footings. A simplified design approach based on conventional lateral pile analysis is presented
Automatic 4-D Registration in Dynamic MR Renography Based on Over-complete Dyadic Wavelet and Fourier Transforms
Dynamic contrast-enhanced 4-D MR renography has the potential for broad clinical applications, but suffers from respiratory motion that limits analysis and interpretation. Since each examination yields at least over 10-20 serial 3-D images of the abdomen, manual registration is prohibitively labor-intensive. Besides in-plane motion and translation, out-of-plane motion and rotation are observed in the image series. In this paper, a novel robust and automated technique for removing out-of-plane translation and rotation with sub-voxel accuracy in 4-D dynamic MR images is presented. The method was evaluated on simulated motion data derived directly from a clinical patient's data. The method was also tested on 24 clinical patient kidney data sets. Registration results were compared with a mutual information method, in which differences between manually co-registered time-intensity curves and tested time-intensity curves were compared. Evaluation results showed that our method agreed well with these ground truth data
Predictive runtime code scheduling for heterogeneous architectures
Heterogeneous architectures are currently widespread. With
the advent of easy-to-program general purpose GPUs, virtually every re-
cent desktop computer is a heterogeneous system. Combining the CPU
and the GPU brings great amounts of processing power. However, such
architectures are often used in a restricted way for domain-speci c appli-
cations like scienti c applications and games, and they tend to be used
by a single application at a time. We envision future heterogeneous com-
puting systems where all their heterogeneous resources are continuously
utilized by di erent applications with versioned critical parts to be able
to better adapt their behavior and improve execution time, power con-
sumption, response time and other constraints at runtime. Under such a
model, adaptive scheduling becomes a critical component.
In this paper, we propose a novel predictive user-level scheduler based on
past performance history for heterogeneous systems. We developed sev-
eral scheduling policies and present the study of their impact on system
performance. We demonstrate that such scheduler allows multiple appli-
cations to fully utilize all available processing resources in CPU/GPU-
like systems and consistently achieve speedups ranging from 30% to 40%
compared to just using the GPU in a single application mode.Postprint (published version
The STAR Time Projection Chamber: A Unique Tool for Studying High Multiplicity Events at RHIC
The STAR Time Projection Chamber (TPC) is used to record collisions at the
Relativistic Heavy Ion Collider (RHIC). The TPC is the central element in a
suite of detectors that surrounds the interaction vertex. The TPC provides
complete coverage around the beam-line, and provides complete tracking for
charged particles within +- 1.8 units of pseudo-rapidity of the center-of-mass
frame. Charged particles with momenta greater than 100 MeV/c are recorded.
Multiplicities in excess of 3,000 tracks per event are routinely reconstructed
in the software. The TPC measures 4 m in diameter by 4.2 m long, making it the
largest TPC in the world.Comment: 28 pages, 11 figure
A narrative analysis of career transition themes and outcomes using chaos theory as a guiding metaphor
In a rapidly changing world of work little research exists on mid-career transitions. We investigated these using the open-systems approach of chaos theory as a guiding metaphor and conducted interviews with seven mid-career individuals chosen for their experience of a significant mid-career transition. Four common themes were identified through narrative analysis, where âfalse startsâ to a career were a common experience prior to finding a career âfitâ. Career transitions, precipitated by a trigger state and/or event such as a period of disillusionment, were an important part of this âfinding a fitâ process. Overall, career success outcomes were shaped by a combination of chaos elements: chance, unplanned events, and non-linearity of resultant outcomes. We discuss implications for future research and for practice
Numerical evolutions of nonlinear r-modes in neutron stars
Nonlinear evolution of the gravitational radiation (GR) driven instability in
the r-modes of neutron stars is studied by full numerical 3D hydrodynamical
simulations. The growth of the r-mode instability is found to be limited by the
formation of shocks and breaking waves when the dimensionless amplitude of the
mode grows to about three in value. This maximum mode amplitude is shown by
numerical tests to be rather insensitive to the strength of the GR driving
force. Upper limits on the strengths of possible nonlinear mode--mode coupling
are inferred. Previously unpublished details of the numerical techniques used
are presented, and the results of numerous calibration runs are discussed.Comment: RevTeX 4, 17 pages, 26 figures. Slightly revised. To be published in
PRD (April 2002
Search for Neutral Higgs Bosons of the Minimal Supersymmetric Standard Model in e+e- Interactions at \sqrt{s} = 189 GeV
A search for the lightest neutral scalar and neutral pseudoscalar Higgs
bosons in the Minimal Supersymmetric Standard Model is performed using 176.4
pb^-1 of integrated luminosity collected by L3 at a center-of-mass energy of
189 GeV. No signal is observed, and the data are consistent with the expected
Standard Model background. Lower limits on the masses of the lightest neutral
scalar and pseudoscalar Higgs bosons are given as a function of tan(beta).
Lower mass limits for tan(beta)>1 are set at the 95% confidence level to be m_h
> 77.1 GeV and m_A > 77.1 GeV
Search for Extra Dimensions in Boson and Fermion Pair Production in e+e- Interactions at LEP
Extra spatial dimensions are proposed by recent theories that postulate the
scale of gravity to be of the same order as the electroweak scale. A sizeable
interaction between gravitons and Standard Model particles is then predicted.
Effects of these new interactions in boson and fermion pair production are
searched for in the data sample collected at centre-of-mass energies above the
Z pole by the L3 detector at LEP. In addition, the direct production of a
graviton associated with a Z boson is investigated. No statistically
significant hints for the existence of these effects are found and lower limits
in excess of 1 TeV are derived on the scale of this new theory of gravity
Measurement of the Probability of Gluon Splitting into Charmed Quarks in Hadronic Z Decays
We have measured the probability, n(g->cc~), of a gluon splitting into a
charm-quark pair using 1.7 million hadronic Z decays collected by the L3
detector. Two independent methods have been applied to events with a three-jet
topology. One method relies on tagging charmed hadrons by identifying a lepton
in the lowest energy jet. The other method uses a neural network based on
global event shape parameters. Combining both methods, we measure n(g->cc~)=
[2.45 +/- 0.29 +/- 0.53]%
Measurement of Triple-Gauge-Boson Couplings of the W Boson at LEP
We report on measurements of the triple-gauge-boson couplings of the W boson
in e+e- collisions with the L3 detector at LEP. W-pair, single-W and
single-photon events are analysed in a data sample corresponding to a total
luminosity of 76.7 pb^{-1} collected at centre-of-mass energies between 161 GeV
and 183 GeV. CP-conserving as well as both C- and P-conserving
triple-gauge-boson couplings are determined. The results, in good agreement
with the Standard-Model expectations, confirm the existence of the self
coupling among the electroweak gauge bosons and constrain its structure
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