229 research outputs found

    Diagnosis of rotor fault using neuro-fuzzy inference system

    Get PDF
    The three-phase induction machines (IM) is large importance and are being widely used as electromechanical system device regarding for their robustness, reliability, and simple design with well developed technologies. This work presents a reliable method for diagnosis and detection of rotor broken bars faults in induction machine. The detection faults are based on monitoring of the current signal. Also the calculation of the value of relative energy for each level of signal decomposition using package wavelet, which will be useful as data input of adaptive Neuro-Fuzzy inference system (ANFIS). In this method, fuzzy logic is used to make decisions about the machine state. The adaptive Neuro-Fuzzy inference system is able to identify the IM bearing state with high precision. This technique is applied under the MATLAB®.Keywords: Induction Machine; Diagnosis; Detection; Neuro-Fuzzy inference system

    THE SYNDROME OF OVERTRAINING AMONG THE ALGERIAN ELITE JUDOKAS (YOUNGER MEMBERS OF THE ALGERIAN NATIONAL TEAM) DURING A COMPETITION FOLLOW-UP

    Get PDF
    Introduction:  The main objective of this study is to detect the existence of a state of fatigue and a syndrome of overtraining among Algerians judokas of the youngest category (girls and boys) by the use of the questionnaire of fatigue among the child athlete (QFES) and to evaluate the variations of the score by report has its 07 dimensions. Method: 24 judokas cadets of the national team, 14 boys 58.3% and 10 girls 41,7%. The boys are an average age of 16.21±0.21 years, an average weight of 67±16,40kg and a stature of 171,64±9,49cm. They have a body mass index(BMI) of 22.69±4.94 kg/m².girls have an average age of 16.20±0.78 years, a weight of 59.1±7.89 kg and a stature of 163.9±3,14cm.The BMI is equal to 21,95±2.50 kg/sq. m. The athletes are attending school between the fourth average year at the College and the second year of secondary school. During the period of the microcycle stage of competition which is taking place between 01 March 2017 and 31 May 2017, we distributed the questionnaire at the end of the competition at the Championship in Algeria (Algiers, 27/05/2017). Results: The score of the questionnaire was to 40.01±8.58 (minimum=27, 00, maximum=54), 33.33% of athletes their scores to the QFES≥45. The average score for an item is 1.1±0.11. The ranking of items of the QFES by average quotation with significant threshold retained of p<0.05. The results are expressed in average ± standard deviation. Conclusion: The main results show that in the questionnaire QFES fatigue is a sensitive tool to detect a state of fatigue. However, a biological study is imperative in order to establish the correlation between syndrome of the overtraining and oxidative stress among young judokas  Article visualizations

    Ion impact induced Interatomic Coulombic Decay in neon and argon dimers

    Full text link
    We investigate the contribution of Interatomic Coulombic Decay induced by ion impact in neon and argon dimers (Ne2_2 and Ar2_2) to the production of low energy electrons. Our experiments cover a broad range of perturbation strengths and reaction channels. We use 11.37 MeV/u S14+^{14+}, 0.125 MeV/u He1+^{1+}, 0.1625 MeV/u He1+^{1+} and 0.150 MeV/u He2+^{2+} as projectiles and study ionization, single and double electron transfer to the projectile as well as projectile electron loss processes. The application of a COLTRIMS reaction microscope enables us to retrieve the three-dimensional momentum vectors of the ion pairs of the fragmenting dimer into Neq+^{q+}/Ne1+^{1+} and Arq+^{q+}/Ar1+^{1+} (q = 1, 2, 3) in coincidence with at least one emitted electron

    A biomechanical model for fibril recruitment: Evaluation in tendons and arteries

    Get PDF
    Simulations of soft tissue mechanobiological behaviour are increasingly important for clinical prediction of aneurysm, tendinopathy and other disorders. Mechanical behaviour at low stretches is governed by fibril straightening, transitioning into load-bearing at recruitment stretch, resulting in a tissue stiffening effect. Previous investigations have suggested theoretical relationships between stress-stretch measurements and recruitment probability density function (PDF) but not derived these rigorously nor evaluated these experimentally. Other work has proposed image-based methods for measurement of recruitment but made use of arbitrary fibril critical straightness parameters. The aim of this work was to provide a sound theoretical basis for estimating recruitment PDF from stress-stretch measurements and to evaluate this relationship using image-based methods, clearly motivating the choice of fibril critical straightness parameter in rat tail tendon and porcine artery. Rigorous derivation showed that the recruitment PDF may be estimated from the second stretch derivative of the first Piola-Kirchoff tissue stress. Image-based fibril recruitment identified the fibril straightness parameter that maximised Pearson correlation coefficients (PCC) with estimated PDFs. Using these critical straightness parameters the new method for estimating recruitment PDF showed a PCC with image-based measures of 0.915 and 0.933 for tendons and arteries respectively. This method may be used for accurate estimation of fibril recruitment PDF in mechanobiological simulation where fibril-level mechanical parameters are important for predicting cell behaviour

    Task-specific transfer of perceptual learning across sensory modalities

    Get PDF
    It is now widely accepted that primary cortical areas of the brain that were once thought to be sensory-specific undergo significant functional reorganisation following sensory deprivation. For instance, loss of vision or audition leads to the brain areas normally associated with these senses being recruited by the remaining sensory modalities [1]. Despite this, little is known about the rules governing crossmodal plasticity in people who experience typical sensory development, or the potential behavioural consequences. Here, we used a novel perceptual learning paradigm to assess whether the benefits associated with training on a task in one sense transfer to another sense. Participants were randomly assigned to a spatial or temporal task that could be performed visually or aurally, which they practiced for five days; before and after training, we measured discrimination thresholds on all four conditions and calculated the extent of transfer between them. Our results show a clear transfer of learning between sensory modalities; however, generalisation was limited to particular conditions. Specifically, learned improvements on the spatial task transferred from the visual domain to the auditory domain, but not vice versa. Conversely, benefits derived from training on the temporal task transferred from the auditory domain to visual domain, but not vice versa. These results suggest a unidirectional transfer of perceptual learning from dominant to non-dominant sensory modalities and place important constraints on models of multisensory processing and plasticity

    phi^4 Kinks - Gradient Flow and Dynamics

    Full text link
    The symmetric dynamics of two kinks and one antikink in classical (1+1)-dimensional Ï•4\phi^4 theory is investigated. Gradient flow is used to construct a collective coordinate model of the system. The relationship between the discrete vibrational mode of a single kink, and the process of kink-antikink pair production is explored.Comment: 23 pages, LaTex, 11 eps figures. We have added some clarification of our metho

    Insights into Hox Protein Function from a Large Scale Combinatorial Analysis of Protein Domains

    Get PDF
    Protein function is encoded within protein sequence and protein domains. However, how protein domains cooperate within a protein to modulate overall activity and how this impacts functional diversification at the molecular and organism levels remains largely unaddressed. Focusing on three domains of the central class Drosophila Hox transcription factor AbdominalA (AbdA), we used combinatorial domain mutations and most known AbdA developmental functions as biological readouts to investigate how protein domains collectively shape protein activity. The results uncover redundancy, interactivity, and multifunctionality of protein domains as salient features underlying overall AbdA protein activity, providing means to apprehend functional diversity and accounting for the robustness of Hox-controlled developmental programs. Importantly, the results highlight context-dependency in protein domain usage and interaction, allowing major modifications in domains to be tolerated without general functional loss. The non-pleoitropic effect of domain mutation suggests that protein modification may contribute more broadly to molecular changes underlying morphological diversification during evolution, so far thought to rely largely on modification in gene cis-regulatory sequences

    Rapid and Reversible Recruitment of Early Visual Cortex for Touch

    Get PDF
    The loss of vision has been associated with enhanced performance in non-visual tasks such as tactile discrimination and sound localization. Current evidence suggests that these functional gains are linked to the recruitment of the occipital visual cortex for non-visual processing, but the neurophysiological mechanisms underlying these crossmodal changes remain uncertain. One possible explanation is that visual deprivation is associated with an unmasking of non-visual input into visual cortex.We investigated the effect of sudden, complete and prolonged visual deprivation (five days) in normally sighted adult individuals while they were immersed in an intensive tactile training program. Following the five-day period, blindfolded subjects performed better on a Braille character discrimination task. In the blindfold group, serial fMRI scans revealed an increase in BOLD signal within the occipital cortex in response to tactile stimulation after five days of complete visual deprivation. This increase in signal was no longer present 24 hours after blindfold removal. Finally, reversible disruption of occipital cortex function on the fifth day (by repetitive transcranial magnetic stimulation; rTMS) impaired Braille character recognition ability in the blindfold group but not in non-blindfolded controls. This disruptive effect was no longer evident once the blindfold had been removed for 24 hours.Overall, our findings suggest that sudden and complete visual deprivation in normally sighted individuals can lead to profound, but rapidly reversible, neuroplastic changes by which the occipital cortex becomes engaged in processing of non-visual information. The speed and dynamic nature of the observed changes suggests that normally inhibited or masked functions in the sighted are revealed by visual loss. The unmasking of pre-existing connections and shifts in connectivity represent rapid, early plastic changes, which presumably can lead, if sustained and reinforced, to slower developing, but more permanent structural changes, such as the establishment of new neural connections in the blind
    • …
    corecore