14 research outputs found

    Illumination of a production facility for communication and electric power cables

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    Sight represents 90% of our sensory everyday life. In specific work conditions, like long distance communication and electric power cable production, sight is by far more important. Work personnel must distinguish between many colours cables in verifying the cable delivered finally after the machine assembling. Errors are very costly since any non-conformity results in an entire production stock rejection. The luminosity in the production facility is estimated by similitude of different room scales and the necessary of artificial illumination. The results will be computed per the level of illumination indicated for production. A scaled-up estimation will be for the production facility, and is corrected with respect to the production equipment situated between the center of the room, occupied by the directing staff, and the facility edges. Equipment and machines are placed in a visible way from the central area occupied by offices. Results are analysed to improve facility design in terms of rectangularity ratio, colour of the walls, ceiling and floor and light sources emplacement

    Parametric and Nonparametric EEG Analysis for the Evaluation of EEG Activity in Young Children with Controlled Epilepsy

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    There is an important evidence of differences in the EEG frequency spectrum of control subjects as compared to epileptic subjects. In particular, the study of children presents difficulties due to the early stages of brain development and the various forms of epilepsy indications. In this study, we consider children that developed epileptic crises in the past but without any other clinical, psychological, or visible neurophysiological findings. The aim of the paper is to develop reliable techniques for testing if such controlled epilepsy induces related spectral differences in the EEG. Spectral features extracted by using nonparametric, signal representation techniques (Fourier and wavelet transform) and a parametric, signal modeling technique (ARMA) are compared and their effect on the classification of the two groups is analyzed. The subjects performed two different tasks: a control (rest) task and a relatively difficult math task. The results show that spectral features extracted by modeling the EEG signals recorded from individual channels by an ARMA model give a higher discrimination between the two subject groups for the control task, where classification scores of up to 100% were obtained with a linear discriminant classifier

    A decision support framework for the discrimination of children with controlled epilepsy based on EEG analysis

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    This work was supported in part by the EC-IST project Biopattern, contract no: 508803, by the EC ICT project TUMOR, contract no: 247754, by the University of Malta grant LBA-73-695, by an internal grant from the Technical University of Crete, ELKE# 80037 and by the Academy of Finland, project nos: 113572, 118355, 134767 and 213462.Background: In this work we consider hidden signs (biomarkers) in ongoing EEG activity expressing epileptic tendency, for otherwise normal brain operation. More specifically, this study considers children with controlled epilepsy where only a few seizures without complications were noted before starting medication and who showed no clinical or electrophysiological signs of brain dysfunction. We compare EEG recordings from controlled epileptic children with age-matched control children under two different operations, an eyes closed rest condition and a mathematical task. The aim of this study is to develop reliable techniques for the extraction of biomarkers from EEG that indicate the presence of minor neurophysiological signs in cases where no clinical or significant EEG abnormalities are observed. Methods: We compare two different approaches for localizing activity differences and retrieving relevant information for classifying the two groups. The first approach focuses on power spectrum analysis whereas the second approach analyzes the functional coupling of cortical assemblies using linear synchronization techniques. Results: Differences could be detected during the control (rest) task, but not on the more demanding mathematical task. The spectral markers provide better diagnostic ability than their synchronization counterparts, even though a combination (or fusion) of both is needed for efficient classification of subjects. Conclusions: Based on these differences, the study proposes concrete biomarkers that can be used in a decision support system for clinical validation. Fusion of selected biomarkers in the Theta and Alpha bands resulted in an increase of the classification score up to 80% during the rest condition. No significant discrimination was achieved during the performance of a mathematical subtraction task.peer-reviewe

    Comparison of single trial back-projected independent components with the averaged waveform for the extraction of biomarkers of auditory P300 EPs

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    The independent components analysis (ICA) of the auditory P300 evoked responses in the EEG of normal subjects is described. The purpose was to identify any features which might provide the basis for biomarkers for diseases, such as Alzheimer’s disease. Single trial P300s were analysed by ICA, the activations were back-projected to scalp electrodes, many artefactual components were removed automatically, and the back-projected independent components (BICs) were first clustered according to their amplitudes and latencies. Then these primary clusters were secondarily clustered according to the columns of their mixing matrices, which clusters together those BICs with the same scalp topographies and, therefore, source locations. The BICs comprising the P300s had simple shapes, approximating half-sinusoids. Trial- to-trial variations in the BICs were found, which explain why different averages have been reported. Both positive- and also negative-going BICs were identified, some associated with known peaks in the P300 waveform. Artefact-free, single trial P300 waveforms could be constructed from the BICs, but these are probably of less interest than the BICs themselves. The findings demonstrate that neither averaged P300s, nor single trial P300s, are reliable as biomarkers, but rather it will be necessary to investigate the BICs present in a number of single trial realizations.peer-reviewe

    To extract the independent components of the evoked potentials in the EEG using ICA

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    The aim was to develop a reliable method of extracting the independent components of single trial evoked potential (EP) signals to derive features for the subject’s bioprofile, for diagnostic, prognostic, and monitoring purposes. Single trials are of interest, because conventional averaging conceals trial-to-trial variability and hence information. Independent Components Analysis (ICA) is a technique for Blind Source Separation (BSS) to recover N temporally independent source signals s = {s1(t), ... sN(t)} from N linear mixtures (the observations), x = {x1(t), ... xN(t)} obtained by multiplying the matrix of unknown sources s by an unknown mixing matrix A, (x = A.s). ICA seeks a square unmixing matrix W such that s = W.x. Difficulties arise for short duration, relatively low amplitude EPs, which have sparse ICs. The effectiveness of different algorithms was compared. Problems associated with more sources than measurement electrodes and with the generation by the algorithms of artefactual components were investigated. Ways of extracting the true EP components were considered. Component grouping was applied to obtain reliable groups, which could be explored for any clinical interpretations. Here we describe the recommended approach as developed by our virtual research group.peer-reviewe

    Illumination of a production facility for communication and electric power cables

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    Sight represents 90% of our sensory everyday life. In specific work conditions, like long distance communication and electric power cable production, sight is by far more important. Work personnel must distinguish between many colours cables in verifying the cable delivered finally after the machine assembling. Errors are very costly since any non-conformity results in an entire production stock rejection. The luminosity in the production facility is estimated by similitude of different room scales and the necessary of artificial illumination. The results will be computed per the level of illumination indicated for production. A scaled-up estimation will be for the production facility, and is corrected with respect to the production equipment situated between the center of the room, occupied by the directing staff, and the facility edges. Equipment and machines are placed in a visible way from the central area occupied by offices. Results are analysed to improve facility design in terms of rectangularity ratio, colour of the walls, ceiling and floor and light sources emplacement

    Modelling of noise reduction for Datacentre buildings fire protection with inert gas systems

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    Regarding INERGEN Clean gas Total Flood Fire Suppression System, these systems are specifically engineered for total flooding application in either unoccupied or occupied areas, but against its design, or their proved long term efficiency and global scale usage, since INERGEN agent is stored as a gas, it discharges as an invisible gas that can have a more destroying impact than the fire itself. Since 2008 up to now, there have been recorded on yearly basis several reports about INERGEN gas discharges conducting to faults in hard discs (HDD) operating in Data Centres protected by such a solution from fire due to the level of noise produced. The paper shows an analysis of this problem as hard disks damaging source detection and optimization by modelling of nozzle placement in the space choice as a technical solution to avoid these fire extinguisher side effects
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