130 research outputs found
Designing power system stabilizer for multimachine power system using neuro-fuzzy algorithm
This paper describes a design procedure for a fuzzy logic based power system stabilizer (FLPSS) and adaptive neuro-fuzzy inference system (ANFIS) and investigates their robustness for a multi-machine power system. Speed deviation of a machine and its derivative are chosen as the input signals to the FLPSS. A four-machine and a two-area power system is used as the case study. Computer simulations for the test system subjected to transient disturbances i.e. a three phase fault, were carried out and the results showed that the proposed controller is able to prove its effectiveness and improve the system damping when compared to a conventional lead-lag based power system stabilizer controller
The Sheffield Mk3.5 absolute resistivity aEIT system – Review of recent updates and future trends
Suitability of PSA-detected localised prostate cancers for focal therapy: Experience from the ProtecT study
This article is available through a Creative Commons Attribution-NonCommercial-Share Alike 3.0 Unported License. Copyright @ 2011 Cancer Research UK.Background: Contemporary screening for prostate cancer frequently identifies small volume, low-grade lesions. Some clinicians have advocated focal prostatic ablation as an alternative to more aggressive interventions to manage these lesions. To identify which patients might benefit from focal ablative techniques, we analysed the surgical specimens of a large sample of population-detected men undergoing radical prostatectomy as part of a randomised clinical trial. Methods: Surgical specimens from 525 men who underwent prostatectomy within the ProtecT study were analysed to determine tumour volume, location and grade. These findings were compared with information available in the biopsy specimen to examine whether focal therapy could be provided appropriately. Results: Solitary cancers were found in prostatectomy specimens from 19% (100 out of 525) of men. In addition, 73 out of 425 (17%) men had multiple cancers with a solitary significant tumour focus. Thus, 173 out of 525 (33%) men had tumours potentially suitable for focal therapy. The majority of these were small, well-differentiated lesions that appeared to be pathologically insignificant (38–66%). Criteria used to select patients for focal prostatic ablation underestimated the cancer's significance in 26% (34 out of 130) of men and resulted in overtreatment in more than half. Only 18% (24 out of 130) of men presumed eligible for focal therapy, actually had significant solitary lesions. Conclusion: Focal therapy appears inappropriate for the majority of men presenting with prostate-specific antigen-detected localised prostate cancer. Unifocal prostate cancers suitable for focal ablation are difficult to identify pre-operatively using biopsy alone. Most lesions meeting criteria for focal ablation were either more aggressive than expected or posed little threat of progression.National Institute for Health Researc
A 4-Week Diet Low or High in Advanced Glycation Endproducts Has Limited Impact on Gut Microbial Composition in Abdominally Obese Individuals : The deAGEing Trial
Dietary advanced glycation endproducts (AGEs), abundantly present in Westernized diets, are linked to negative health outcomes, but their impact on the gut microbiota has not yet been well investigated in humans. We investigated the effects of a 4-week isocaloric and macronutrient-matched diet low or high in AGEs on the gut microbial composition of 70 abdominally obese individuals in a double-blind parallel-design randomized controlled trial (NCT03866343). Additionally, we investigated the cross-sectional associations between the habitual intake of dietary dicarbonyls, reactive precursors to AGEs, and the gut microbial composition, as assessed by 16S rRNA amplicon-based sequencing. Despite a marked percentage difference in AGE intake, we observed no differences in microbial richness and the general community structure. Only the Anaerostipes spp. had a relative abundance >0.5% and showed differential abundance (0.5 versus 1.11%; p = 0.028, after low- or high-AGE diet, respectively). While the habitual intake of dicarbonyls was not associated with microbial richness or a general community structure, the intake of 3-deoxyglucosone was especially associated with an abundance of several genera. Thus, a 4-week diet low or high in AGEs has a limited impact on the gut microbial composition of abdominally obese humans, paralleling its previously observed limited biological consequences. The effects of dietary dicarbonyls on the gut microbiota composition deserve further investigation.Peer reviewe
Comparison of black-, white-, and grey-box models to predict ultimate tensile strength of high-strength hot rolled coils at the Port Talbot hot strip mill
Non-Linear Circuit Mode Analysis
An exposition is given of recent advances in the theoretical analysis of circuits comprising sets of intercoupled non-linear oscillators. Motivation for this work has come from mathematical modelling of biomedical systems, particularly for the electrical activity of the gastro-intestinal digestive tract. Over the past few years a matrix linearisation method has been developed and applied to a wide range of structures comprising chains, arrays, rings and tubes. Also, different coupling components including pur time delay and two types of van der Pol oscillator dynamics have neeb investigated. Numerous mode patterns have been predicted and experimentally observed and stability criteria established for a wide range of conditions. The multi-oscillator mode analysis entails a two-stage process comprising matrix mode decoupling followed by equivalent linearisation similar to the Krylov-Bogolioubov approach
Hybrid Self-Organising Fuzzy Logic PID Controllers for Muscle Relaxation Anaesthesia
Hybrid PID forms of SOFLC were investigated in computer simulation for controlling muscle relaxation in the operating theatre with a view to reducing computational requirements and comparing their control performance. A 5×5 fuzzy rule base was used and an efficient fuzzy inferencing procedure identified which uses singletons for input and output fuzzy sets. The performance of a self-organising fuzzy PD+I controller was compared with a self-organising PI+I controller in computer simulations with regard to noise tolerance and tracking ability with a fixed setpoint and changing process gain. Both self-organising fuzzy logic controllers have similar control performance under the simulated condition. The SOFPD+I controller output is considerably more variable than the SOFPI+I controller under high noise conditions but gives a faster response to genuine process changes under low noise conditions
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