1,721,028 research outputs found
5G beamforming implementation and trade-off investigation of cylindrical array arrangements
Full text linkIn this paper, we study the performance of a 5G network working at mmW range for the uplink. We consider a single base station scenario equipped with a cylindrical array and a circular array (which can be seen as a single ring cylindrical array), isotropic and directive antenna elements are taken into account and we evaluate the trade-off between antennas per ring and number of rings with fixed number of total antennas. Users are modeled as a spatial Binomial point process in a hexagonal cell. As beamforming techniques, Conventional and Capon algorithms have been considered. As main KPI to evaluate system performance, we consider average achievable per-user rate with different system configurations, such as network loading. The key result of the trade-off investigation is that, when the radius of the cell is much larger than the height of the base station, the best performance occurs when the cylindrical array degenerates in a circular array both when users lay at ground level and with random heights
Orthodontic treatment with self ligating multibraket appliance in adult. 5 years Follow-up
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Performance Analysis of Multi-User MIMO Schemes under Realistic 3GPP 3-D Channel Model for 5G mmWave Cellular Networks
Full text linkNovel techniques such as mmWave transmission and massive MIMO have proven to present many attractive features able to support high data demand for 5G NR technologies. Towards the standardization of 5G networks, channel modeling has become an important step in order to test the reliability of theoretical studies. In this paper, we study the performance of a 5G network at mmWave range for the downlink. We consider a single trisectorized base station equipped with planar arrays, and we model users as a spatial Poisson process in a hexagonal grid. We adopt the latest 3GPP channel model described in TR 38.901 and we provide a thorough description and step-by-step tutorial of it along with our customizations and MATLAB scripts for channel generation in the presented scenario. Moreover, we evaluate the performance of Multi-User Multi-Layer MIMO techniques, such as Signal-to-Leakage-plus-Noise Ratio (SLNR) precoding and MMSE combined with different system configurations by means of achievable per-user rate
Analysis of circular and cylindrical array arrangements for mmwave 5G beamforming techniques
Full text linkIn this paper, we study the performance of a 5G base station working in the mmWave range equipped with a cylindrical array. Conventional and Capon beamforming techniques are taken into account. We consider both isotropic and directive antenna elements and we evaluate the trade-off between antennas per ring and number of rings with fixed number of total antennas. Results are provided in terms of average achievable per-user rate with different system configurations, such as of network loading. We show that in the presented scenario, where users are randomly deployed in a hexagonal plane, the best performance occurs when the cylindrical array degenerates in a circular array
Abnormal cortical facilitation and L-dopa-induced dyskinesia in Parkinson's disease
Full text linkBackground: Animal models of Parkinson's Disease (PD) demonstrated increased facilitatory cortico-striatal activity, reflecting overactive glutamatergic neurotransmission and contributing to the pathophysiology of L-dopa induced dyskinesias (LIDs). Objective: To assess different facilitatory intracortical circuits in the primary motor cortex (M1) in patients with PD and LIDs by means of a combination of transcranial magnetic stimulation (TMS) protocols. Methods: We tested the Input/Output (I/O) curve, intracortical facilitation (ICF) and short-interval intracortical facilitation (SICF) at baseline (T0), ‘OFF’ and ‘ON’ state, in 20 PD patients with LIDs. The same parameters were examined after 2 weeks of chronic intake of 50 mg (T1) and 100 mg/day (T2) of safinamide. Finally, we tested SICF in a further group of patients without LIDs. Results: At T0, patients with LIDs showed increased I/O curve steepness, which was partly ameliorated by L-dopa. These patients also had normal ICF, and abnormally increased SICF, which did not change with L-dopa. Safinamide improved the I/O curve both at T1 and T2, it reduced SICF at T1 and normalized this measure at T2. In patients with PD and LIDs, SICF correlated with the severity of dyskinesia. In patients without LIDs, SICF was less prominently abnormal and responsive to L-dopa. Conclusions: Patients with PD and LIDs have abnormal cortical facilitation, possibly suggesting overactive glutamatergic neurotransmission in specific circuits within M1. Although not responsive to L-dopa, this dysfunction is restored by the anti-glutamatergic properties of safinamide 100 mg. The results suggest that the abnormal cortical facilitation in M1 contributes to the pathophysiology of LIDs
Influence of Thermodynamic on ECS Control in DLC Maneuver
No full textThe interaction between brakes and tires is crucial for the safety and performance of motor vehicles. This study aims to examine this interaction considering the thermodynamic evolution of tires and evaluating the differences in the dynamic behavior of the vehicle and then of the behavior of ESC (Electronic Stability Control). In particular, it focus on the detailed analysis of the “Double Lane Chang” maneuver once the thermodynamic evolution of the tires over time has been implemented. The results provide an important understanding of the braking and steering dynamics of vehicles, contributing to suggesting possible future developments to optimize safety and performance
Evolution of EEG patterns in cerebral reperfusion syndrome after carotid artery stenting
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Information reconciliation (IR) for continuous variable quantum key distribution (QKD) over free space optics (FSO) channel
No full textQuantum Key Distribution (QKD) is a communication method which exchanges secret keys using cryptographic protocols involving elements from quantum science. Continuous Variable (CV) QKD is a method to implement key exchange using sampling of Gaussian signals. Reconciliation in CV-QKD is fundamentally realized via coding of the Alice or Bob binary labels of the Gaussian samples using either one-way or interactive communications between the parties, Alice and Bob, over a public authenticated channel. We assume that the communication is performed through an Optical Wireless (OW) or Free Space Optics (FSO) channel. In that case the received signal suffers from stochastic fading due to pointing jitter or atmospheric turbulence. As a result of the channel fading and noise Alice and Bob Gaussian samples will not match. Information Reconciliation (IR) is the phase of the CV-QKD protocol that makes sure that Alice and Bob agree on a common and identical labeling of their samples, i.e. agree on a common stream of bits that we denote as “reconciled key.” The information reconciliation in CV-QKD could be done by one-way or two-way channel coding to correct the actual labels so that they do match. To do so Bob generates a sequence of parity bits using a systematic code. These bits are sent to Alice over an authenticated public channel. Alice then uses her own sequence of labels she obtains after quantization with the redundancy provided by Bob to recover Bob’s binary sequence. In this work we analyze the problem of information reconciliation for continuous variable quantum key distribution over a free space optics channel
Controlled Growth of Large SiO2 Shells onto Semiconductor Colloidal Nanocrystals: A Pathway Toward Photonic Integration
Full text linkThe growth of SiO2 shells on semiconductor nanocrystals is an established procedure and it is widely employed to provide dispersibility in polar solvents, and increased stability or biocompatibility. However, to exploit this shell to integrate photonic components on semiconductor nanocrystals, the growth procedure must be finely tunable and able to reach large particle sizes (around 100 nm or above). Here, we demonstrate that these goals are achievable through a design of experiment approach. Indeed, the use of a sequential full-factorial design allows us to carefully tune the growth of SiO2 shells to large values while maintaining a reduced size dispersion. Moreover, we show that the growth of a dielectric shell alone can be beneficial in terms of emission efficiency for the nanocrystal. We also demonstrate that, according to our modeling, the subsequent growth of two shells with increasing refractive index leads to an improved emission efficiency already at a reduced SiO2 sphere radius
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