38 research outputs found

    Performance Evaluation of Adaptive Cooperative NOMA Protocol at Road Junctions

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    Vehicular communications (VCs) protocols offer useful contributions in the context of accident prevention thanks to the transmission of alert messages. This is even truer at road intersections since these areas exhibit higher collision risks and accidents rate. On the other hand, non-orthogonal multiple access (NOMA) has been show to be a suitable candidate for five generation (5G) of wireless systems. In this paper, we propose and evaluate the performance of VCs protocol at road intersections, named adaptive cooperative NOMA (ACN) protocol. The transmission occurs between a source and two destinations. The transmission is subject to interference originated from vehicles located on the roads. The positions of the interfering vehicles follow a Poison point process (PPP). First, we calculate the outage probability related to ACN protocol, and closed form expressions are obtained. Then we compare it with other existing protocols in the literature. We show that ACN protocol offers a significant improvement over the existing protocols in terms of outage probability, especially at the intersection. We show that the performance of ACN protocol increases compared to other existing protocols for high data rates. The theoretical results are verified with Monte-Carlo simulations

    HyT-NAS: Hybrid Transformers Neural Architecture Search for Edge Devices

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    Vision Transformers have enabled recent attention-based Deep Learning (DL) architectures to achieve remarkable results in Computer Vision (CV) tasks. However, due to the extensive computational resources required, these architectures are rarely implemented on resource-constrained platforms. Current research investigates hybrid handcrafted convolution-based and attention-based models for CV tasks such as image classification and object detection. In this paper, we propose HyT-NAS, an efficient Hardware-aware Neural Architecture Search (HW-NAS) including hybrid architectures targeting vision tasks on tiny devices. HyT-NAS improves state-of-the-art HW-NAS by enriching the search space and enhancing the search strategy as well as the performance predictors. Our experiments show that HyT-NAS achieves a similar hypervolume with less than ~5x training evaluations. Our resulting architecture outperforms MLPerf MobileNetV1 by 6.3% accuracy improvement with 3.5x less number of parameters on Visual Wake Words.Comment: CODAI 2022 Workshop - Embedded System Week (ESWeek

    Electronics Properties of Monoclinic HfO2

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    Density functional theory (DFT) is a very successful technique to calculating the properties of manyelectron systems from first principles. The bands structures, charge density and density of state (DOS) of monoclinic HfO2 are calculated using Pseudo potential (PP) and Atomic Orbitals (AO) method, within the density functional theory DFT, generalized gradient approximation GGA and local density approximation LDA. Hafnium oxide (HfO2) is a high-k dielectric (dielectric constant k ~ 25 at 300 K, band gap Eg ≈ 6 eV); thermally stable up to 700 ◦C. HfO2 is used in semiconductor manufacturing processes where they are usually used to replace a silicon dioxide gate dielectric

    EXPERIMENTAL AND NUMERICAL INVESTIGATION OF COMBUSTION BEHAVIOUR IN DIESEL ENGINE FUELLED WITH WASTE POLYETHYLENE OIL

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    The aim of this investigation is to evaluate the usability of waste polyethylene oil as an alternative fuel for diesel engines. The novel fuel is obtained by a pyrolysis process of waste polyethylene at 973 K. The obtained oil is tested in a single cylinder air cooled (TS1) direct injection diesel engine at 1500 rpm. Engine performances and exhaust pollutant emissions from Waste Polyethylene Oil (WPO) were analysed and compared to those obtained from the same engine fuelled with conventional diesel fuel. Results showed that the total fuel consumption of WPO is lower than that of neat diesel fuel due to the higher heating value of WPO. Brake Thermal Efficiency (BTE) is improved for WPO especially at low load. The exhaust gas temperature is lower for WPO than that of diesel at low and full load. CO and UHC are found lower, while NOx emissions are higher at high loads. Furthermore, the use of numerical investigation permits to optimize the injection parameters, which can help to take advantages of WPO fuel. The simulation results suggest advancing the injection timing

    Congenital adrenal hyperplasia due to 11-Beta-hydroxylase deficiency in a Tunisian family

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    Congenital adrenal hyperplasia refers to a group of rare genetic disorders affecting the adrenal glands. 21-hydroxylase deficiency is the most prevalent and the most studied cause while the remaining enzymatic defects are less common, accounting for less than 10% of cases. We herein described the clinical, biological and molecular characteristics and outcome of patients of the same family diagnosed with 11-Beta-hydroxylase deficiency. The disorder was revealed by peripheral precocious puberty between the age of 2-3 years in males and by the virilization of the external genitalia in females. Genetics finding a homozygous p.Gly379Val mutation in the CYP11B1 gene. All patients received hydrocortisone supplementation therapy and mineralocorticoid-receptor antagonist. The females underwent a surgical correction of the ambiguous genitalia at the neonatal age. Long term follow-up revealed metabolic syndrome, obesity and hypertension in the first two patients, an impaired final height in the two females and hypokalemia in three patients
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