589 research outputs found
Application of particle swarm optimization algorithm to multiuser detection in CDMA
Multiple access interference and near-far effect cause performance limitation in the conventional single-user detector used in direct sequence/code division multiple access (DS-CDMA)-systems. In this paper, we present a novel multiuser detector (MUD) based on the new heuristic algorithm known as particle swarm algorithm (MUDPSO). We evaluate the BER performance of the proposed algorithm, by means of Monte Carlo simulation technique, and compare it to the BER performances of both the matched filter detector and the decorrelator multiuser detectors. We show that the new algorithm outperforms the other two. Moreover, the performance under near-far scenario, the system capacity and the computational complexity of the proposed detector are also investigated
Application of particle swarm optimization algorithm to multiuser detection in CDMA
Multiple access interference and near-far effect cause performance limitation in the conventional single-user detector used in direct sequence/code division multiple access (DS-CDMA)-systems. In this paper, we present a novel multiuser detector (MUD) based on the new heuristic algorithm known as particle swarm algorithm (MUDPSO). We evaluate the BER performance of the proposed algorithm, by means of Monte Carlo simulation technique, and compare it to the BER performances of both the matched filter detector and the decorrelator multiuser detectors. We show that the new algorithm outperforms the other two. Moreover, the performance under near-far scenario, the system capacity and the computational complexity of the proposed detector are also investigated
Machine Learning-Based Fault Diagnosis for a PWR Nuclear Power Plant
In the nuclear power industry, safety and reliability are of the utmost importance. Sensors and actuators are integral components in such systems, and potential faults may adversely impact system performance. It is therefore imperative to design a fault detection and diagnosis (FDD) system that achieves the highest standards of safety. This paper presents a machine learning-based fault detection and diagnosis (FDD) technique for actuators and sensors in a pressurized water reactor (PWR). In the proposed FDD framework, faults are first detected using a shallow neural network. Second, fault diagnosis is performed using 15 different classifiers provided in the MATLAB Classification Learner toolbox, including support vector machine (SVM), K-nearest neighbor (KNN), and ensemble. Several classifiers were found to provide superior classification performance, including medium KNN, cubic KNN, cosine KNN, weighted KNN, fine Gaussian SVM, quadratic SVM, medium Gaussian SVM, coarse Gaussian, bagged trees, and subspace KNN. The accuracy of the FDD approach was demonstrated using a set of simulation results
Risk-stratified faecal immunochemical testing (FIT) for urgent colonoscopy in Lynch syndrome during the COVID-19 pandemic
BACKGROUND: Lynch syndrome is a hereditary cancer disease resulting in an increased risk of colorectal cancer. Herein, findings are reported from an emergency clinical service implemented during the COVID-19 pandemic utilizing faecal immunochemical testing ('FIT') in Lynch syndrome patients to prioritize colonoscopy while endoscopy services were limited. METHODS: An emergency service protocol was designed to improve colonoscopic surveillance access throughout the COVID-19 pandemic in England for people with Lynch syndrome when services were extremely restricted (1 March 2020 to 31 March 2021) and promoted by the English National Health Service. Requests for faecal immunochemical testing from participating centres were sent to the National Health Service Bowel Cancer Screening South of England Hub and a faecal immunochemical testing kit, faecal immunochemical testing instructions, paper-based survey, and pre-paid return envelope were sent to patients. Reports with faecal haemoglobin results were returned electronically for clinical action. Risk stratification for colonoscopy was as follows: faecal haemoglobin less than 10 µg of haemoglobin/g of faeces (µg/g)-scheduled within 6-12 weeks; and faecal haemoglobin greater than or equal to 10 µg/g-triaged via an urgent suspected cancer clinical pathway. Primary outcomes of interest included the identification of highest-risk Lynch syndrome patients and determining the impact of faecal immunochemical testing in risk-stratified colonoscopic surveillance. RESULTS: Fifteen centres participated from June 2020 to March 2021. Uptake was 68.8 per cent amongst 558 patients invited. For 339 eligible participants analysed, 279 (82.3 per cent) had faecal haemoglobin less than 10 µg/g and 60 (17.7 per cent) had faecal haemoglobin greater than or equal to 10 µg/g. In the latter group, the diagnostic accuracy of faecal immunochemical testing was 65.9 per cent and escalation to colonoscopy was facilitated (median 49 versus 122 days, χ2 = 0.0003, P < 0.001). CONCLUSION: Faecal immunochemical testing demonstrated clinical value for Lynch syndrome patients requiring colorectal cancer surveillance during the pandemic in this descriptive report of an emergency COVID-19 response service. Further longitudinal investigation on faecal immunochemical testing efficacy in Lynch syndrome is warranted and will be examined under the 'FIT for Lynch' study (ISRCTN15740250)
Improving data availability for brain image biobanking in healthy subjects: practice-based suggestions from an international multidisciplinary working group
International audienceBrain imaging is now ubiquitous in clinical practice and research. The case for bringing together large amounts of image data from well-characterised healthy subjects and those with a range of common brain diseases across the life course is now compelling. This report follows a meeting of international experts from multiple disciplines, all interested in brain image biobanking. The meeting included neuroimaging experts (clinical and non-clinical), computer scientists, epidemiologists, clinicians, ethicists, and lawyers involved in creating brain image banks. The meeting followed a structured format to discuss current and emerging brain image banks; applications such as atlases; conceptual and statistical problems (e.g. defining 'normality'); legal, ethical and technological issues (e.g. consents, potential for data linkage, data security, harmonisation, data storage and enabling of research data sharing). We summarise the lessons learned from the experiences of a wide range of individual image banks, and provide practical recommendations to enhance creation, use and reuse of neuroimaging data. Our aim is to maximise the benefit of the image data, provided voluntarily by research participants and funded by many organisations, for human health. Our ultimate vision is of a federated network of brain image biobanks accessible for large studies of brain structure and function
Mobilization of genomic islands of Staphylococcus aureus by temperate bacteriophage
The virulence of Staphylococcus aureus, in both human and animal hosts, is largely influenced by the acquisition of mobile genetic elements (MGEs). Most S. aureus strains carry a variety of MGEs, including three genomic islands (νSaα, νSaβ, νSaγ) that are diverse in virulence gene content but conserved within strain lineages. Although the mobilization of pathogenicity islands, phages and plasmids has been well studied, the mobilization of genomic islands is poorly understood. We previously demonstrated the mobilization of νSaβ by the adjacent temperate bacteriophage ϕSaBov from strain RF122. In this study, we demonstrate that ϕSaBov mediates the mobilization of νSaα and νSaγ, which are located remotely from ϕSaBov, mostly to recipient strains belonging to ST151. Phage DNA sequence analysis revealed that chromosomal DNA excision events from RF122 were highly specific to MGEs, suggesting sequence-specific DNA excision and packaging events rather than generalized transduction by a temperate phage. Disruption of the int gene in ϕSaBov did not affect phage DNA excision, packaging, and integration events. However, disruption of the terL gene completely abolished phage DNA packing events, suggesting that the primary function of temperate phage in the transfer of genomic islands is to allow for phage DNA packaging by TerL and that transducing phage particles are the actual vehicle for transfer. These results extend our understanding of the important role of bacteriophage in the horizontal transfer and evolution of genomic islands in S. aureus
Pulmonary cystic disease in HIV positive individuals in the Democratic Republic of Congo: three case reports
Pulmonary emphysema and bronchiectasis in HIV seropositive patients has been described in the presence of injection drug use, malnutrition, repeated opportunistic infections, such as Pneumocytis jirovici pneumonia and Mycobacterium tuberculosis infection, and has been linked to the presence of HIV virus in lung tissue. Given the high burden of pulmonary infections and malnutrition among people living with HIV in resource poor settings, these individuals may be at increased risk of developing pulmonary emphysema, potentially reducing the long term benefit of antiretroviral therapy (ART) if initiated late in the course of HIV infection
Cemented fixed-bearing PFC total knee arthroplasty: survival and failure analysis at 12–17 years
The giant graviton on AdS_{4} x CP^{3} - another step towards the emergence of geometry
We construct the giant graviton on AdS_{4} x CP^{3} out of a four-brane
embedded in and moving on the complex projective space. This configuration is
dual to the totally anti-symmetric Schur polynomial operator
\chi_{R}(A_{1}B_{1}) in the 2+1-dimensional, N = 6 super Chern-Simons ABJM
theory. We demonstrate that this BPS solution of the D4-brane action is
energetically degenerate with the point graviton solution and initiate a study
of its spectrum of small fluctuations. Although the full computation of this
spectrum proves to be analytically intractable, by perturbing around a "small'"
giant graviton, we find good evidence for a dependence of the spectrum on the
size, \alpha_{0}, of the giant. This is a direct result of the changing shape
of the worldvolume as it grows in size.Comment: 46 pages, 7 figures. Further details added to section 6 - the
solutions to the leading order fluctuation equations and the leading order
spectrum have been obtained - and additional comments added to the
discussion. Additional references added. Mistake in section 2 correcte
Heterogeneity in semantic priming effect with a lexical decision task in patients after left hemisphere stroke
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