180 research outputs found

    On the Relay-Fallback Tradeoff in Millimeter Wave Wireless System

    Full text link
    Millimeter wave (mmWave) communications systems are promising candidate to support extremely high data rate services in future wireless networks. MmWave communications exhibit high penetration loss (blockage) and require directional transmissions to compensate for severe channel attenuations and for high noise powers. When blockage occurs, there are at least two simple prominent options: 1) switching to the conventional microwave frequencies (fallback option) and 2) using an alternative non-blocked path (relay option). However, currently it is not clear under which conditions and network parameters one option is better than the other. To investigate the performance of the two options, this paper proposes a novel blockage model that allows deriving maximum achievable throughput and delay performance of both options. A simple criterion to decide which option should be taken under which network condition is provided. By a comprehensive performance analysis, it is shown that the right option depends on the payload size, beam training overhead, and blockage probability. For a network with light traffic and low probability of blockage in the direct link, the fallback option is throughput- and delay-optimal. For a network with heavy traffic demands and semi-static topology (low beam-training overhead), the relay option is preferable.Comment: 6 pages, 5 figures, accepted in IEEE INFOCOM mmNet Worksho

    Backscattering UWB/UHF hybrid solutions for multi-reader multi-tag passive RFID systems

    Get PDF
    Ultra-wideband (UWB) technology is foreseen as a promising solution to overcome the limits of ultra-high frequency (UHF) techniques toward the development of green radio frequency identification (RFID) systems with low energy consumption and localization capabilities. While UWB techniques have been already employed for active tags, passive tags solutions are more appealing also due to their lower cost. With the fundamental requirement of maintaining backward compatibility in the RFID domain, we propose a hybrid UWB/UHF architecture to improve passive tag identification both in single-reader and multi-reader scenarios. We then develop two hybrid algorithms: the first one exploits the UWB signal to improve ISO/IEC 18000-6C UHF standard, while the other one exploits UWB to enhance a compressive sensing (CS) technique for tag identification in the multi-reader, multi-tag scenario. Both solutions are able to improve success rate and reading speed in the tag identification process and reduce the energy consumption. The multi-reader version of the proposed approaches is based on a cooperative scheme in order to manage reader-tag collisions and reader-reader collisions besides the typical tag-tag collisions. Furthermore, timing synchronization non-idealities are analyzed for the proposed solutions and simulation results reveal the effectiveness of the developed schemes

    BIPOLAR AND BORDERLINE PERSONALITY DISORDERS: A DESCRIPTIVE COMPARISON OF PSYCHOPATHOLOGICAL ASPECTS IN PATIENTS DISCHARGED FROM AN ITALIAN INPATIENT UNIT USING PANSS AND BPRS

    Get PDF
    Background: There is current scientific debate in consideration of the possibility to consider the Borderline Personality Disorder (BPD) as a mood disorder within the bipolar spectrum furthermore, authors reported about the challenging differential diagnosis of BPD and Bipolar Disorder (BD). Subjects and methods: 32 patients hospitalized in the Inpatient Psychiatric Unit in Perugia, discharged with a diagnosis of BD or BPD, were included. Factor analyses of BPRS and PANSS items were performed. Association between socio-demographic, clinical and psychopathological variables was tested using bivariate analyses. Results: Factor analysis identified 6 Factors, explaining 67.6% of the variance, interpreted as follow: 1) Euphoric Mania, 2) Psychosis, 3) Inhibited Depression, 4) Disorganization, 5) Psychosomatic features, and 6) Mixed features. Bivariate analyses identified statistically significant differences between BPD and BD according to: PANSS positive symptoms domain, BPRS total score, Euphoric Mania and Disorganization. No statistically significant differences came up on socio-demographic and clinical aspects. Conclusion: Even though the sample is small, interesting findings came out from our investigation. Our findings are in line with the current literature. Euphoric mood, is one of the aspects which best differentiated BD from BPD. Higher scores in Disorganization, BPRS and PANSS positive symptoms in BD may be related to the fact that our sample is a group of patients from an acute inpatient unit, so the impact of the symptoms severity for BD may be remarkable

    A quantum-inspired version of the nearest mean classifier

    Get PDF
    We introduce a framework suitable for describing standard classification problems using the mathematical language of quantum states. In particular, we provide a one-to-one correspondence between real objects and pure density operators. This correspondence enables us: (1) to represent the nearest mean classifier (NMC) in terms of quantum objects, (2) to introduce a quantum-inspired version of the NMC called quantum classifier (QC). By comparing the QC with the NMC on different datasets, we show how the first classifier is able to provide additional information that can be beneficial on a classical computer with respect to the second classifier

    Demo: Automatic Personal Identification System for Security in Critical Services: A Case Study

    No full text
    ISBN: 978-1-4503-0718-5International audienceThe demonstration proposal moves from the capabilities of a wireless biometric badge [4], which integrates a localization and tracking service along with an automatic personal identification mechanism, to show how a full system architecture is devised to enable the control of physical accesses to restricted areas. The system leverages on the availability of a novel IEEE 802.15.4/Zigbee Cluster Tree network model, on enhanced security levels and on the respect of all the users' privacy issues

    More than antioxidant: N-acetyl-L-cysteine in a murine model of endometriosis

    Get PDF
    N-acetyl-L-cysteine exerts a complex action on endometrial cells, involving regulation of gene expression and protein activity and location, all converging into a decreased proliferation and a switch toward a differentiating, less invasive, and less inflammatory phenotype. Also considering the lack of undesired side effects, including unaffected fertility potential, this suggests a beneficial use of NAC in endometriosis clinical treatment. Copyright © 2010 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved

    Vasodilators in Septic Shock Resuscitation: A Clinical Perspective

    Get PDF
    ABSTRACT: Microcirculatory abnormalities have been shown to be frequent in patients with septic shock despite “normalization” of systemic hemodynamics. Several studies have explored the impact of vasodilator therapy (prostacyclin, inhaled nitric oxide, topic acetylcholine and nitroglycerin) on microcirculation and tissue perfusion, with contradictory findings.In this narrative review, we briefly present the pathophysiological aspects of microcirculatory dysfunction, and depict the evidence supporting the use of vasodilators and other therapeutic interventions (fluid administration, blood transfusion, vasopressors and dobutamine) aiming to improve the microcirculatory flow in septic shock patients
    corecore