62 research outputs found
Fast Cell Discovery in mm-wave 5G Networks with Context Information
The exploitation of mm-wave bands is one of the key-enabler for 5G mobile
radio networks. However, the introduction of mm-wave technologies in cellular
networks is not straightforward due to harsh propagation conditions that limit
the mm-wave access availability. Mm-wave technologies require high-gain antenna
systems to compensate for high path loss and limited power. As a consequence,
directional transmissions must be used for cell discovery and synchronization
processes: this can lead to a non-negligible access delay caused by the
exploration of the cell area with multiple transmissions along different
directions.
The integration of mm-wave technologies and conventional wireless access
networks with the objective of speeding up the cell search process requires new
5G network architectural solutions. Such architectures introduce a functional
split between C-plane and U-plane, thereby guaranteeing the availability of a
reliable signaling channel through conventional wireless technologies that
provides the opportunity to collect useful context information from the network
edge.
In this article, we leverage the context information related to user
positions to improve the directional cell discovery process. We investigate
fundamental trade-offs of this process and the effects of the context
information accuracy on the overall system performance. We also cope with
obstacle obstructions in the cell area and propose an approach based on a
geo-located context database where information gathered over time is stored to
guide future searches. Analytic models and numerical results are provided to
validate proposed strategies.Comment: 14 pages, submitted to IEEE Transaction on Mobile Computin
Passive and Privacy-preserving Human Localization via mmWave Access Points for Social Distancing
The pandemic outbreak has profoundly changed our life, especially our social
habits and communication behaviors. While this dramatic shock has heavily
impacted human interaction rules, novel localization techniques are emerging to
help society in complying with new policies, such as social distancing.
Wireless sensing and machine learning are well suited to alleviate viruses
propagation in a privacy-preserving manner. However, its wide deployment
requires cost-effective installation and operational solutions. In public
environments, individual localization information-such as social
distancing-needs to be monitored to avoid safety threats when not properly
observed. To this end, the high penetration of wireless devices can be
exploited to continuously analyze-and-learn the propagation environment,
thereby passively detecting breaches and triggering alerts if required. In this
paper, we describe a novel passive and privacy-preserving human localization
solution that relies on the directive transmission properties of mmWave
communications to monitor social distancing and notify people in the area in
case of violations. Thus, addressing the social distancing challenge in a
privacy-preserving and cost-efficient manner. Our solution provides an overall
accuracy of about 99% in the tested scenarios
An Orchestration Framework for Open System Models of Reconfigurable Intelligent Surfaces
To obviate the control of reflective intelligent surfaces (RISs) and the
related control overhead, recent works envisioned autonomous and
self-configuring RISs that do not need explicit use of control channels.
Instead, these devices, named hybrid RISs (HRISs), are equipped with receiving
radio-frequency (RF) chains and can perform sensing operations to act
independently and in parallel to the other network entities. A natural problem
then emerges: as the HRIS operates concurrently with the communication
protocols, how should its operation modes be scheduled in time such that it
helps the network while minimizing any undesirable effects? In this paper, we
propose an orchestration framework that answers this question revealing an
engineering trade-off, called the self-configuring trade-off, that
characterizes the applicability of self-configuring HRISs under the
consideration of massive multiple-input multiple-output (mMIMO) networks. We
evaluate our proposed framework considering two different HRIS hardware
architectures, the power- and signal-based HRISs that differ in their hardware
complexity. The numerical results show that the self-configuring HRIS can offer
significant performance gains when adopting our framework.Comment: 31 pages, 7 figures, submitted to an IEEE journa
Use of Biomarkers in Ongoing Research Protocols on Alzheimer's Disease
The present study aimed to describe and discuss the state of the art of biomarker use in ongoing Alzheimer's disease (AD) research. A review of 222 ongoing phase 1, 2, 3, and 4 protocols registered in the clinicaltrials.gov database was performed. All the trials (i) enrolling subjects with clinical disturbances and/or preclinical diagnoses falling within the AD continuum; and (ii) testing the efficacy and/or safety/tolerability of a therapeutic intervention, were analyzed. The use of biomarkers of amyloid deposition, tau pathology, and neurodegeneration among the eligibility criteria and/or study outcomes was assessed. Overall, 58.2% of ongoing interventional studies on AD adopt candidate biomarkers. They are mostly adopted by studies at the preliminary stages of the drug development process to explore the safety profile of novel therapies, and to provide evidence of target engagement and disease-modifying properties. The biologically supported selection of participants is mostly based on biomarkers of amyloid deposition, whereas the use of biomarkers as study outcomes mostly relies on markers of neurodegeneration. Biomarkers play an important role in the design and conduction of research protocols targeting AD. Nevertheless, their clinical validity, utility, and cost-effectiveness in the "real world" remain to be clarified
Riluzole use in presence of contraindications in adults affected by amyotrophic lateral sclerosis and its off-label use in other motor neuron diseases: Findings from an Italian multicentre study (the {CAESAR} project)
Background: This analysis describes the use of riluzole in amyotrophic lateral sclerosis (ALS) individuals with contraindications and off-label use for subjects with other motor neuron diseases (o-MND) in the Italian regions of Latium, Tuscany and Umbria.Methods: A cohort of adults with ALS prescribed with riluzole during the years 2016–2019 was enrolled from administrative healthcare databases, excluding subjects with o-MND in the preceding 5 years. Being affected by ALS for more than 5 years, presence of tracheostomy, renal or hepatic failure were considered as contraindications to the use of riluzole. A cohort of adults with o-MND was enrolled in 2016–2019 for whom off-label use of riluzole was retrieved up to 4 years, analysing over the time differences related to sex.Results: Among 206 ALS individuals prescribed with riluzole in Latium, 336 in Tuscany and 60 in Umbria, less than 1% were diagnosed with ALS for more than 5 years. Less than 2% were tracheotomised or affected by hepatic failure. Renal failure was documented for 1.9%, 2.7%, and 5.0% of ALS individuals in Latium, Tuscany and Umbria. The o-MND cohort comprised 264 subjects in Latium, 222 in Tuscany, and 66 in Umbria. Non-negligible off-label riluzole use was observed: 8.5%, 33.0%, and 4.2% in females, and 19.9%, 26.5% and 2.4% in males in Latium, Tuscany and Umbria.Discussion: Riluzole use in ALS individuals in the presence of contraindications is rare, with slightly higher numbers in presence of renal failure. Off-label use in o-MND was found to be non-negligible, with variations between sexes
A Systematic Review of the Biological Processes Involved in Deep-Brain Stimulation for Parkinson's disease: A Focus on the Potential Disease-Modifying Effects
Deep-Brain Stimulation (DBS) is an important treatment option for the management of Parkinson's disease (PD) and is a common symptomatic treatment. However, an increasing number of studies have examined the biological processes to assess if DBS can also modify the natural history of PD by acting on its pathophysiological mechanisms. Relevant literature published up to November 2020 was systematically searched on databases such as PubMed, ISI Web of Knowledge, Academic Search Index, and Science Citation Index. The following predefined inclusion criteria were applied to the full-text versions of the selected articles: i) recruiting and monitoring of PD subjects that were previously treated with DBS and ii) investigating the electrophysiological, biochemical, epigenetic, or neuroimaging effects of DBS. Studies focusing exclusively on motor and clinical changes were excluded. Reviews, case reports, studies on animal models, and computational studies were also not considered. Out of 2,960 records screened, 43 studies met the inclusion criteria. Only three studies described a potential disease-modifying effect of DBS. However, a wide heterogeneity was observed in the investigated biomarkers, and the design and methodological issues of several studies limited their ability to find potential disease-modifying features. Specifically, 60.4% of the trials followed-up subjects for no more than 1 year from the surgical intervention, and 67.4% observed patients with PD only once after DBS. Moreover, 64.2% of the studies enrolled late-stage PD patients. Most of the studies (88.4%) reported that DBS only had a symptomatic effect, with several of them showing some limitations in the study design and recruitment of patients. Further studies using shared biomarkers are encouraged to assess if and how DBS might affect the progression of PD. Based on the existing preclinical literature, prospective clinical trials examining the course of PD in early-stage patients are needed
Towards versatile access networks (Chapter 3)
Compared to its previous generations, the 5th generation (5G) cellular network features an additional type of densification, i.e., a large number of active antennas per access point (AP) can be deployed. This technique is known as massive multipleinput multiple-output (mMIMO) [1]. Meanwhile, multiple-input multiple-output (MIMO) evolution, e.g., in channel state information (CSI) enhancement, and also on the study of a larger number of orthogonal demodulation reference signal (DMRS) ports for MU-MIMO, was one of the Release 18 of 3rd generation partnership project (3GPP Rel-18) work item. This release (3GPP Rel-18) package approval, in the fourth quarter of 2021, marked the start of the 5G Advanced evolution in 3GPP. The other items in 3GPP Rel-18 are to study and add functionality in the areas of network energy savings, coverage, mobility support, multicast broadcast services, and positionin
Il metodo della scala di deflusso nel monitoraggio delle portate nei corsi d'acqua di montagna
Dottorato di ricerca in metodi e tecnologie per il monitoraggio ambientale. 8. ciclo. Supervisori I. Becchi e V. A. CopertinoConsiglio Nazionale delle Ricerche - Biblioteca Centrale - P.le Aldo Moro, 7, Rome; Biblioteca Nazionale Centrale - P.za Cavalleggeri, 1, Florence / CNR - Consiglio Nazionale delle RichercheSIGLEITItal
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