31 research outputs found

    Behavior modeling for a beacon-based indoor location system

    Get PDF
    In this work we performed a comparison between two different approaches to track a person in indoor environments using a locating system based on BLE technology with a smartphone and a smartwatch as monitoring devices. To do so, we provide the system architecture we designed and describe how the different elements of the proposed system interact with each other. Moreover, we have evaluated the system’s performance by computing the mean percentage error in the detection of the indoor position. Finally, we present a novel location prediction system based on neural embeddings, and a soft-attention mechanism, which is able to predict user’s next location with 67% accuracy

    Muon `Depth -- Intensity' Relation Measured by LVD Underground Experiment and Cosmic-Ray Muon Spectrum at Sea Level

    Get PDF
    We present the analysis of the muon events with all muon multiplicities collected during 21804 hours of operation of the first LVD tower. The measured angular distribution of muon intensity has been converted to the `depth -- vertical intensity' relation in the depth range from 3 to 12 km w.e.. The analysis of this relation allowed to derive the power index, γ\gamma, of the primary all-nucleon spectrum: γ=2.78±0.05\gamma=2.78 \pm 0.05. The `depth -- vertical intensity' relation has been converted to standard rock and the comparison with the data of other experiments has been done. We present also the derived vertical muon spectrum at sea level.Comment: 7 pages, 3 figures, to be published on Phys. Rev.

    Upper Limit on the Prompt Muon Flux Derived from the LVD Underground Experiment

    Get PDF
    We present the analysis of the muon events with all muon multiplicities collected during 21804 hours of operation of the first LVD tower. The measured depth-angular distribution of muon intensities has been used to obtain the normalization factor, A, the power index, gamma, of the primary all-nucleon spectrum and the ratio, R_c, of prompt muon flux to that of pi-mesons - the main parameters which determine the spectrum of cosmic ray muons at the sea level. The value of gamma = 2.77 +/- 0.05 (68% C.L.) and R_c < 2.0 x 10^-3 (95% C.L.) have been obtained. The upper limit to the prompt muon flux favours the models of charm production based on QGSM and the dual parton model.Comment: 10 pages, 4 figures, RevTex. To appear in Phys. Rev.

    Global overview of the management of acute cholecystitis during the COVID-19 pandemic (CHOLECOVID study)

    Get PDF
    Background: This study provides a global overview of the management of patients with acute cholecystitis during the initial phase of the COVID-19 pandemic. Methods: CHOLECOVID is an international, multicentre, observational comparative study of patients admitted to hospital with acute cholecystitis during the COVID-19 pandemic. Data on management were collected for a 2-month study interval coincident with the WHO declaration of the SARS-CoV-2 pandemic and compared with an equivalent pre-pandemic time interval. Mediation analysis examined the influence of SARS-COV-2 infection on 30-day mortality. Results: This study collected data on 9783 patients with acute cholecystitis admitted to 247 hospitals across the world. The pandemic was associated with reduced availability of surgical workforce and operating facilities globally, a significant shift to worse severity of disease, and increased use of conservative management. There was a reduction (both absolute and proportionate) in the number of patients undergoing cholecystectomy from 3095 patients (56.2 per cent) pre-pandemic to 1998 patients (46.2 per cent) during the pandemic but there was no difference in 30-day all-cause mortality after cholecystectomy comparing the pre-pandemic interval with the pandemic (13 patients (0.4 per cent) pre-pandemic to 13 patients (0.6 per cent) pandemic; P = 0.355). In mediation analysis, an admission with acute cholecystitis during the pandemic was associated with a non-significant increased risk of death (OR 1.29, 95 per cent c.i. 0.93 to 1.79, P = 0.121). Conclusion: CHOLECOVID provides a unique overview of the treatment of patients with cholecystitis across the globe during the first months of the SARS-CoV-2 pandemic. The study highlights the need for system resilience in retention of elective surgical activity. Cholecystectomy was associated with a low risk of mortality and deferral of treatment results in an increase in avoidable morbidity that represents the non-COVID cost of this pandemic

    Juvenile hallux valgus. Aetiopathogenetic aspects and surgical techniques.

    No full text
    Definitions, ethiology and surgical treatment of juvenile hallux valgus. Surgical technique by soft tissues procedures, clinical results, literature review and experts' opinion

    Towards a comprehensive data lifecycle model for big data environments

    No full text

    The combined use of IoT and Blockchain in Logistics: a comparative experiment

    No full text
    In the last decades, thanks to their ubiquitousness, IoT devices have become part of our lives by introducing innovative services that simplify common activities and, therefore, enhance people daily activities and duties. In addition, their usefulness has been further amplified by the combination of the IoT services with various technologies and innovations. For instance, the Distributed Ledger Technologies (DLTs) and the blockchains are supporting the IoT domain with their useful services and properties, e.g., trust and automation, since some years. However, the increasing interest in such a combination and the race towards the most significant innovation in the sector is shifting the focus away from some of the most important issues and questions. One of them regards the usefulness of the adopted technologies and their effectiveness with respect to similar alternative solutions. For example, the most frequently used approach to save data in a DLT foresees the simultaneous use of an off-chain database to store the actual data, and a DLT platform itself to guarantee some properties, e.g. to verify the immutability of such data. Such a common practice is adopted by almost every work on the domain but the real benefits brought by this approach are not usually measured. For this reason, the present paper is focused on an evaluation of two approaches: one based on the combination of DLT and off-chain databases, and the other one based only on the usage of the DLT. A realistic logistics use case has been introduced to compare the performances of each approach
    corecore