1,762 research outputs found
Protocol for the United Kingdom Rotator Cuff Study (UKUFF) : a randomised controlled trial of open and arthroscopic rotator cuff repair
This project was funded by the NIHR Health Technology Assessment programme (project number 05/47/02). J. L. Rees has received a grant from Oxford University which is related to this paper. J. Dawson reports that Oxford University has received a grant from HTA which is related to this paper, as well as a study grant.Peer reviewedPublisher PD
The influence of facies heterogeneity on the doublet performance in low-enthalpy geothermal sedimentary reservoirs
AbstractA three-dimensional model is used to study the influence of facies heterogeneity on energy production under different operational conditions of low-enthalpy geothermal doublet systems. Process-based facies modelling is utilised for the Nieuwerkerk sedimentary formation in the West Netherlands Basin to construct realistic reservoir models honouring geological heterogeneity. A finite element based reservoir simulator is used to model the fluid flow and heat transfer over time. A series of simulations is carried out to examine the effects of reservoir heterogeneity (Net-to-Gross ratio, N/G) on the life time and the energy recovery rate for different discharge rates and the production temperature (Tmin) above which the doublet is working. With respect to the results, we propose a design model to estimate the life time and energy recovery rate of the geothermal doublet. The life time is estimated as a function of N/G, Tmin and discharge rate, while the design model for the energy recovery rate is only a function of N/G and Tmin. Both life time and recovery show a positive relation with an increasing N/G. Further our results suggest that neglecting details of process-based facies modelling may lead to significant errors in predicting the life time of low-enthalpy geothermal systems for N/G values below 70%
A high-quality video denoising algorithm based on reliable motion estimation
11th European Conference on Computer Vision, Heraklion, Crete, Greece, September 5-11, 2010, Proceedings, Part IIIAlthough the recent advances in the sparse representations of images have achieved outstanding denosing results, removing real, structured noise in digital videos remains a challenging problem. We show the utility of reliable motion estimation to establish temporal correspondence across frames in order to achieve high-quality video denoising. In this paper, we propose an adaptive video denosing framework that integrates robust optical flow into a non-local means (NLM) framework with noise level estimation. The spatial regularization in optical flow is the key to ensure temporal coherence in removing structured noise. Furthermore, we introduce approximate K-nearest neighbor matching to significantly reduce the complexity of classical NLM methods. Experimental results show that our system is comparable with the state of the art in removing AWGN, and significantly outperforms the state of the art in removing real, structured noise
Extensions to the charge exchange recombination spectroscopy diagnostic suite at ASDEX Upgrade
A new core charge exchange recombination spectroscopy diagnostic has been installed in the ASDEX
Upgrade tokamak that is capable of measuring the impurity ion temperature, toroidal rotation, and
density on both the low field side (LFS) and high field side (HFS) of the plasma. The new system
features 48 lines-of-sight (LOS) with a radial resolution that varies from
±
2 cm on the LFS down
to
±
0.75 cm on the HFS and has sufficient signal to run routinely at 10 ms and for special circum-
stances down to 2.5 ms integration time. The LFS-HFS ion temperature profiles provide an additional
constraint on the magnetic equilibrium reconstruction, and the toroidal rotation frequency profiles
are of sufficiently high quality that information on the poloidal velocity can be extracted from the
LFS-HFS asymmetry. The diagnostic LOS are coupled to two flexible-wavelength spectrometers such
that complete LFS-HFS profiles from two separate impurities can be imaged simultaneously, albeit
with reduced radial coverage. More frequently, the systems measure the same impurity providing very
detailed information on the chosen species. Care has been taken to calibrate the systems as accurately
as possible and to include in the data analysis any effects that could lead to spurious temperatures or
rotations.European Commission (EUROfusion 633053
The role of smoking and body mass index in mortality risk assessment for geriatric hip fracture patients
Background Smoking, obesity, and being below a healthy body weight are known to increase all-cause mortality rates and are considered modifiable risk factors. The purpose of this study is to assess whether adding these risk factors to a validated geriatric inpatient mortality risk tool will improve the predictive capacity for hip fracture patients. We hypothesize that the predictive capacity of the Score for Trauma Triage in the Geriatric and Middle-Aged (STTGMA) tool will improve. Methodology Between October 2014 and August 2021, 2,421 patients \u3e55-years-old treated for hip fractures caused by low-energy mechanisms were analyzed for demographics, injury details, hospital quality measures, and mortality. Smoking status was recorded as a current every-day smoker, former smoker, or never smoker. Smokers (current and former) were compared to non-smokers (never smokers). Body mass index (BMI) was defined as underweight (\u3c18.5 kg/
Complexity of multi-dimensional spontaneous EEG decreases during propofol induced general anaesthesia
Emerging neural theories of consciousness suggest a correlation between a specific type of neural dynamical complexity and the level of consciousness: When awake and aware, causal interactions between brain regions are both integrated (all regions are to a certain extent connected) and differentiated (there is inhomogeneity and variety in the interactions). In support of this, recent work by Casali et al (2013) has shown that Lempel-Ziv complexity correlates strongly with conscious level, when computed on the EEG response to transcranial magnetic stimulation. Here we investigated complexity of spontaneous high-density EEG data during propofol-induced general anaesthesia. We consider three distinct measures: (i) Lempel-Ziv complexity, which is derived from how compressible the data are; (ii) amplitude coalition entropy, which measures the variability in the constitution of the set of active channels; and (iii) the novel synchrony coalition entropy (SCE), which measures the variability in the constitution of the set of synchronous channels. After some simulations on Kuramoto oscillator models which demonstrate that these measures capture distinct ‘flavours’ of complexity, we show that there is a robustly measurable decrease in the complexity of spontaneous EEG during general anaesthesia
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