804 research outputs found

    Enhanced fault diagnosis of DFIG converter systems

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    Neural Correlates of Auditory Perceptual Awareness and Release from Informational Masking Recorded Directly from Human Cortex: A Case Study.

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    In complex acoustic environments, even salient supra-threshold sounds sometimes go unperceived, a phenomenon known as informational masking. The neural basis of informational masking (and its release) has not been well-characterized, particularly outside auditory cortex. We combined electrocorticography in a neurosurgical patient undergoing invasive epilepsy monitoring with trial-by-trial perceptual reports of isochronous target-tone streams embedded in random multi-tone maskers. Awareness of such masker-embedded target streams was associated with a focal negativity between 100 and 200 ms and high-gamma activity (HGA) between 50 and 250 ms (both in auditory cortex on the posterolateral superior temporal gyrus) as well as a broad P3b-like potential (between ~300 and 600 ms) with generators in ventrolateral frontal and lateral temporal cortex. Unperceived target tones elicited drastically reduced versions of such responses, if at all. While it remains unclear whether these responses reflect conscious perception, itself, as opposed to pre- or post-perceptual processing, the results suggest that conscious perception of target sounds in complex listening environments may engage diverse neural mechanisms in distributed brain areas

    Statistical analysis of factors associated with recent traffic accidents dataset: a practical study

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    In this paper, we propose a logistic model to fit accidents dataset of 10,000 road crash incidents for the Emirate of Abu Dhabi published in 2020. After cleaning up the dataset, we use descriptive and inferential statistical tools to study the attributes of each variable. Then, we identify the main independent variables that can be incorporated in a general logistic regression model which also includes the interactions between them. Our analysis using the significance level of (alpha = 0.05) found that there is a reduced logistic regression model that can fit the data in which the ‘location of accident’ can be represented using ‘type of accident’ and the ‘age’ of people involved in the accidents. Moreover, the results show that the interaction terms are not significant to be included in the model. Furthermore, the study shows that the odds for accidents by young age group (less than 40 years old) in external streets is 27% higher than the odds for internal streets, and that the odds for sequential type accidents in external streets is 13% higher than the odds for internal streets

    Reduction of pavement thickness using a subgrade layer treated by different techniques

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    A range of stabilisers for poor quality subgrade soils have been developed to promote road constructions. Many of them are becoming more popular depending on their effectiveness. The purpose behind this research is to identify the relative efficacy of many physical and chemical stabilisation techniques for enhancing the properties of three types of local Iraqi subgrade soils. The comparison of the samples is based on the CBR tests. The AASHTO (1993) flexible pavement design was used to compute the pavement thickness requirements. The soil samples A, B and C have a natural CBR values of 3.8, 3.9 and 4, respectively, on which the physical stabilisers of Powdered rock (PR), grained recycled concrete (GRC), and recycled crumb rubber grains (CR) were employed, while Quicklime (QL) and activated fly ash (AFA) were both utilised as chemical stabilisers. The stabilisation with 15 % of AFA proved to be the most applicable method for soil types A and B for reducing the pavement thickness requirements by 51 % and 32 %, respectively, with a reasonable financial feasibility for both. The same feasibility is proven when stabilising soil type C with 15 % of GRC, which reduces the pavementthickness by 25.7 %

    VLSI low-power digital signal processing

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    Biometric Template Protection based on Hill Cipher Algorithm with Two Invertible Keys

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    The security of stored templates has become an important issue in biometric authentication systems this because most of the biometric attacks target the biometric database beside the difficulty of issuing the templates again. Thus, to protect the biometric templates it must be encrypted before storing in database. In this paper we proposed an efficient encryption method based on two invertible and random keys to enhance and overcome the weakness of hill cipher algorithm the keys generated using upper triangular matrices with Pseudo-Random Number Generator (PRNG) using two large and random encryption keys. The proposed encryption method provides sufficient security and protection for the biometric templates from attacks, where the experimental results showed high efficiency comparing with the traditional Hill Cipher and existing methods

    Characterizing the spiking dynamics of subthalamic nucleus neurons in Parkinson's disease using generalized linear models

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    Accurately describing the spiking patterns of neurons in the subthalamic nucleus (STN) of patients suffering from Parkinson's disease (PD) is important for understanding the pathogenesis of the disease and for achieving the maximum therapeutic benefit from deep brain stimulation (DBS). We analyze the spiking activity of 24 subthalamic neurons recorded in Parkinson's patients during a directed hand movement task by using a point process generalized linear model (GLM). The model relates each neuron's spiking probability simultaneously to factors associated with movement planning and execution, directional selectivity, refractoriness, bursting, and oscillatory dynamics. The model indicated that while short-term history dependence related to refractoriness and bursting are most informative in predicting spiking activity, nearly all of the neurons analyzed have a structured pattern of long-term history dependence such that the spiking probability was reduced 20–30 ms and then increased 30–60 ms after a previous spike. This suggests that the previously described oscillatory firing of neurons in the STN of Parkinson's patients during volitional movements is composed of a structured pattern of inhibition and excitation. This point process model provides a systematic framework for characterizing the dynamics of neuronal activity in STN
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