2,621 research outputs found

    Parameter Estimation Using Least Square Method for MIMO Takagi-Sugeno Neuro-Fuzzy in TIME Series Forecasting

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    This paper describes LSE method for improving Takagi-Sugeno neuro-fuzzy model for a multi-input and multi-output system using a set of data (Mackey-Glass chaotic time series). The performance of the generated model is verified using certain set of validation / test data. The LSE method is used to compute the consequent parameters of Takagi-Sugeno neuro-fuzzy model while mean and variance of Gaussian Membership Functions are initially set at certain values and will be updated using Back Propagation Algorithm. The simulation using Matlab shows that the developed neuro-fuzzy model is capable of forecasting the future values of the chaotic time series and adaptively reduces the amount of error during its training and validation

    A new type of charged defect in amorphous chalcogenides

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    We report on density-functional-based tight-binding (DFTB) simulations of a series of amorphous arsenic sulfide models. In addition to the charged coordination defects previously proposed to exist in chalcogenide glasses, a novel defect pair, [As4]--[S3]+, consisting of a four-fold coordinated arsenic site in a seesaw configuration and a three-fold coordinated sulfur site in a planar trigonal configuration, was found in several models. The valence-alternation pairs S3+-S1- are converted into [As4]--[S3]+ pairs under HOMO-to-LUMO electronic excitation. This structural transformation is accompanied by a decrease in the size of the HOMO-LUMO band gap, which suggests that such transformations could contribute to photo-darkening in these materials.Comment: 5 pages, 2 figure

    Frequency and Circadian Timing of Eating May Influence Biomarkers of Inflammation and Insulin Resistance Associated with Breast Cancer Risk.

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    Emerging evidence suggests that there is interplay between the frequency and circadian timing of eating and metabolic health. We examined the associations of eating frequency and timing with metabolic and inflammatory biomarkers putatively associated with breast cancer risk in women participating in the National Health and Nutrition Examination 2009-2010 Survey. Eating frequency and timing variables were calculated from 24-hour food records and included (1) proportion of calories consumed in the evening (5 pm-midnight), (2) number of eating episodes per day, and (3) nighttime fasting duration. Linear regression models examined each eating frequency and timing exposure variable with C-reactive protein (CRP) concentrations and the Homeostatic Model Assessment of Insulin Resistance (HOMA-IR). Each 10 percent increase in the proportion of calories consumed in the evening was associated with a 3 percent increase in CRP. Conversely, eating one additional meal or snack per day was associated with an 8 percent reduction in CRP. There was a significant interaction between proportion of calories consumed in the evening and fasting duration with CRP (p = 0.02). A longer nighttime fasting duration was associated with an 8 percent lower CRP only among women who ate less than 30% of their total daily calories in the evening (p = 0.01). None of the eating frequency and timing variables were significantly associated with HOMA-IR. These findings suggest that eating more frequently, reducing evening energy intake, and fasting for longer nightly intervals may lower systemic inflammation and subsequently reduce breast cancer risk. Randomized trials are needed to validate these associations

    Systems Thinking Using SSM and TRIZ for Stakeholder Engagement in Infrastructure Megaprojects

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    Infrastructure megaprojects straddle multiple stakeholder boundaries who have an interest in the project and are affected by the project. Multiple papers in the literature stress the need for holistic approaches to stakeholder engagement, as existing approaches only address the concerns of the noisy stakeholders. This research proposes an innovative approach in which Soft Systems Methodology (SSM) is used for understanding stakeholder concerns, complemented by the use of Theory of Inventive Problem Solving (TRIZ) for identifying innovative solutions to address conflicting stakeholder goals. The researchers simulated the stakeholder engagement of the Coimbatore metro rail project, in India, through a workshop setting in a classroom to check the feasibility of this approach for stakeholder engagement. The 15 participants of the workshop were divided into four groups representing different stakeholders of the project. Data was collected through participant observations by the authors and oral feedback from the participants. The results show that while SSM helped to capture the concerns and goals of each stakeholder, TRIZ helped to identify and dissolve conflicts among these goals through innovative solutions. The theoretical, practical and pedagogical contributions are highlighted

    Towards a second generation of spatial planning in the UK?

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    A New Survey for Giant Arcs

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    We report on the first results of an imaging survey to detect strong gravitational lensing targeting the richest clusters selected from the photometric data of the Sloan Digital Sky Survey (SDSS) with follow-up deep imaging observations from the Wisconsin Indiana Yale NOAO (WIYN) 3.5m telescope and the University of Hawaii 88-inch telescope (UH88). The clusters are selected from an area of 8000 deg^2 using the Red Cluster Sequence technique and span the redshift range 0.1 < z < 0.6, corresponding to a comoving cosmological volume of ~ 2 Gpc^3. Our imaging survey thus targets a volume more than an order of magnitude larger than any previous search. A total of 240 clusters were imaged of which 141 had sub-arcsecond image quality. Our survey has uncovered16 new lensing clusters with definite giant arcs, an additional 12 systems for which the lensing interpretation is very likely, and 9 possible lenses which contain shorter arclets or candidate arcs which are less certain and will require further observations to confirm their lensing origin. The number of new cluster lenses detected in this survey is likely > 30. Among these new systems are several of the most dramatic examples of strong gravitational lensing ever discovered with multiple bright arcs at large angular separation. These will likely become 'poster-child' gravitational lenses similar to Abell 1689 and CL0024+1654. The new lenses discovered in this survey will enable future sysetmatic studies of the statistics of strong lensing and its implications for cosmology and our structure formation paradigm.Comment: 19 pages, 7 pages of Figures, submitted to AJ. Fixed Typo

    Cosmological Implications of the Very High Redshift GRB 050904

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    We report near simultaneous multi-color (RIYJHK) observations made with the MAGNUM 2m telescope of the gamma ray burst GRB 050904 detected by the SWIFT satellite. The spectral energy distribution shows a very large break between the I and J bands. Using intergalactic transmissions measured from high redshift quasars we show that the observations place a 95% confidence lower limit of z=6.18 on the object, consistent with a later measured spectroscopic redshift of 6.29 obtained by Kawai et al. (2005) with the Subaru telescope. We show that the break strength in the R and I bands is consistent with that measured in the quasars. Finally we consider the implications for the star formation history at high redshift.Comment: Accepted for publication in the Astrophysical Journal. Expanded introduction and discussio

    Impact of COVID-19 on stroke admissions, treatments, and outcomes at a comprehensive stroke centre in the United Kingdom

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    Introduction The coronavirus disease (COVID-19) pandemic has changed routine clinical practice worldwide with major impacts on the provision of care and treatment for stroke patients. Methods This retrospective observational study included all patients admitted to the Royal Stoke University Hospital in Stokeon-Trent, UK, with a stroke or transient ischaemic attack between March 15th and April 14th, 2020 (COVID). Patient demographics, characteristics of the stroke, treatment details and logistics were compared with patients admitted in the corresponding weeks in the year before (2019). Results There was a 39.5% (n = 101 vs n = 167) reduction in admissions in the COVID cohort compared with 2019 with more severe strokes (median National Institutes of Health Stroke Scale (NIHSS) 7 vs 4, p = 0.02), and fewer strokes with no visible acute pathology (21.8 vs 37.1%, p = 0.01) on computed tomography. There was no statistically significant difference in the rates of thrombolysis (10.9 vs 13.2%, p = 0.72) and/or thrombectomy (5.9 vs 4.8%, p = 0.90) and no statistically significant difference in time from stroke onset to arrival at hospital (734 vs 576 min, p = 0.34), door-to-needle time for thrombolysis (54 vs 64 min, p = 0.43) and door-to-thrombectomy time (181 vs 445 min, p = 0.72). Thirty-day mortality was not significantly higher in the COVID year (10.9 vs 8.9%, p = 0.77). None of the 7 stroke patients infected with COVID-19 died. Conclusions During the COVID-19 pandemic, the number of stroke admissions fell, and stroke severity increased. There was no statistically significant change in the delivery of thrombolysis and mechanical thrombectomy and no increase in mortality
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