2,146 research outputs found

    Sol–gel-derived photonic structures handling erbium ions luminescence

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    The sol–gel technique is a very flexible, relatively simple, and low-cost method to fabricate many different innovative photonic structures characterized by specific functionalities. During synthesis, starting from the molecular level, compounds or composites with well controlled composition can be obtained as thin films, powders or monoliths. These materials can be used to prepare such structures as waveguides, photonic crystals, coatings, and bulk glasses including spheres, rings and other geometries exploited in optical resonators fabrication. This article presents some results obtained by the authors in the field of the sol–gel-derived photonic structures. To emphasise the scientific and technological interest in this kind of systems and the versatility of the sol–gel route, the glass-based nano and micrometer scale range systems are discussed. Particularly, the following systems are described: silica–hafnia glass and glass–ceramic planar waveguides, nanosized tetraphosphates, and silica colloidal crystals. The attention is focused on the spectroscopic properties of Er3+-activated materials that due to the light emission can be used in the integrated optics area covering application in sensing, biomedical diagnostic, energy conversion, telecommunication, lighting, and photon management

    A bank of unscented Kalman filters for multimodal human perception with mobile service robots

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    A new generation of mobile service robots could be ready soon to operate in human environments if they can robustly estimate position and identity of surrounding people. Researchers in this field face a number of challenging problems, among which sensor uncertainties and real-time constraints. In this paper, we propose a novel and efficient solution for simultaneous tracking and recognition of people within the observation range of a mobile robot. Multisensor techniques for legs and face detection are fused in a robust probabilistic framework to height, clothes and face recognition algorithms. The system is based on an efficient bank of Unscented Kalman Filters that keeps a multi-hypothesis estimate of the person being tracked, including the case where the latter is unknown to the robot. Several experiments with real mobile robots are presented to validate the proposed approach. They show that our solutions can improve the robot's perception and recognition of humans, providing a useful contribution for the future application of service robotics

    An upgraded version of the Eta model

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    Upgrades implemented over a number of years in an open source version of the Eta Model, posted at the CPTEC web site http://etamodel.cptec.inpe.br/, are summarized and examples of benefits are shown. The version originates from the NCEP's Workstation Eta code posted on the NCEP web site http://www.emc.ncep.noaa.gov/mmb/wrkstn_eta, which differs from the NCEP's latest operational Eta by having the WRF-NMM nonhydrostatic option included. Most of the upgrades made resulted from attention paid to less than satisfactory performance noted in several Eta results, and identification of the reasons for the problem. Others came from simple expectation that including a feature that is physically justified but is missing in the code should help. The most notable of the upgrades are the introduction of the so-called sloping steps, or discretized shaved cells topography; piecewise-linear finite-volume vertical advection of dynamic variables; vapor and hydrometeor loading in the hydrostatic equation, and changes aimed at refining the convection schemes available in the Eta. Several other modifications have to do with the calculation of exchange coefficients, conservation in the vertical diffusion, and diagnostic calculation of 10-m winds. Several examples showing improved performance resulting from the dynamics changes are given. One includes a case of unrealistically low temperatures in several mountain basins generated by a centered vertical advection difference scheme's unphysical advection from below ground, removed by its replacement with a finite-volume scheme. Another is that of increased katabatic winds in the Terra Nova Bay Antarctica region. Successful forecast of the severe downslope zonda winds case in the lee of the highest peaks of the Andes is also shown, and some of the recent successful verification results of the use of the upgraded model are pointed out. The code is used at numerous places, and along with setup information it is available for outside users at the CPTEC Eta web site given above

    Influence of Higenamine on Exercise Performance of Recreational Female Athletes: A Randomized Double-Blinded Placebo-Controlled Trial

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    The aim of this study was to determine the ergogenic effects and the safety profile of a one-component higenamine supplement in female recreational athletes. Twelve recreational female basketball players (age 29–41 years, oxygen consumption (VO2max) > 30 ml⋅kg–1⋅min–1, with training > 5 h wk–1) were randomized either to the higenamine group, or to the placebo group for 3 weeks. In order to determine ergogenic effects and safety profile of higenamine administration, we assessed the following variables before and after 3 weeks of supplementation: anthropometric parameters, resting metabolic rate (RMR), exercise testing variables, serum free fatty acids (FFAs), blood pressure, enzyme activity, urea, lipid profile, and complete blood count. There were no differences between groups in anthropometric parameters, including basal metabolic rate (BMR), RMR and body fat [p = 0.706 (Cohen’s d 0.223), p = 0.169 (Cohen’s d 0.857), and p = 0.223 (Cohen’s d 0.750), respectively], FFAs [0.43 ± 0.03 vs. 0.54 ± 0.23, p = 0.206 (Cohen’s d 0.540)], neither significant differences in cardiopulmonary parameters after the intervention period. Furthermore, all measured outcome variables in the safety assessment were not significant, with values remaining stable during the intervention period for participants in both groups. This is the first study to document the effects and the safety profile of higenamine-based dietary supplements at a specified dose in female recreational athletes. Our data indicate that 21-day of supplementation with 75 mg higenamine would not result in improving cardiopulmonary exercise fitness and weight loss in female recreational athletes. Moreover, supplementation with 75 mg higenamine is safe and well-tolerated in younger recreational female athletes

    Cost-effectiveness of implementing a digital psychosocial intervention for patients with psychotic spectrum disorders in low- and middle-income countries in Southeast Europe: Economic evaluation alongside a cluster randomised trial

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    BACKGROUND: DIALOG+ is a digital psychosocial intervention aimed at making routine meetings between patients and clinicians therapeutically effective. This study aimed to evaluate the cost-effectiveness of implementing DIALOG+ treatment for patients with psychotic disorders in five low- and middle-income countries in Southeast Europe alongside a cluster randomised trial. METHODS: Resource use and quality of life data were collected alongside the multi-country cluster randomised trial of 468 participants with psychotic disorders. Due to COVID-19 interruptions of the trial’s original 12-month intervention period, adjusted costs and quality-adjusted life years (QALYs) were estimated at the participant level using a mixed-effects model over the first 6 months only. We estimated the incremental cost-effectiveness ratio (ICER) with uncertainty presented using a cost-effectiveness plane and a cost-effectiveness acceptability curve. Seven sensitivity analyses were conducted to check the robustness of the findings. RESULTS: The average cost of delivering DIALOG+ was €91.11 per participant. DIALOG+ was associated with an incremental health gain of 0.0032 QALYs (95% CI –0.0015, 0.0079), incremental costs of €84.17 (95% CI –8.18, 176.52), and an estimated ICER of €26,347.61. The probability of DIALOG+ being cost-effective against three times the weighted gross domestic product (GDP) per capita for the five participating countries was 18.9%. CONCLUSION: Evidence from the cost-effectiveness analyses in this study suggested that DIALOG+ involved relatively low costs. However, it is not likely to be cost-effective in the five participating countries compared with standard care against a willingness-to-pay threshold of three times the weighted GDP per capita per QALY gained

    HV/HR-CMOS sensors for the ATLAS upgrade—concepts and test chip results

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    In order to extend its discovery potential, the Large Hadron Collider (LHC) will have a major upgrade (Phase II Upgrade) scheduled for 2022. The LHC after the upgrade, called High-Luminosity LHC (HL-LHC), will operate at a nominal leveled instantaneous luminosity of 5× 1034 cm−2 s−1, more than twice the expected Phase I . The new Inner Tracker needs to cope with this extremely high luminosity. Therefore it requires higher granularity, reduced material budget and increased radiation hardness of all components. A new pixel detector based on High Voltage CMOS (HVCMOS) technology targeting the upgraded ATLAS pixel detector is under study. The main advantages of the HVCMOS technology are its potential for low material budget, use of possible cheaper interconnection technologies, reduced pixel size and lower cost with respect to traditional hybrid pixel detector. Several first prototypes were produced and characterized within ATLAS upgrade R&D effort, to explore the performance and radiation hardness of this technology. In this paper, an overview of the HVCMOS sensor concepts is given. Laboratory tests and irradiation tests of two technologies, HVCMOS AMS and HVCMOS GF, are also given

    Radiation-hard active pixel sensors for HL-LHC detector upgrades based on HV-CMOS technology

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    Luminosity upgrades are discussed for the LHC (HL-LHC) which would make updates to the detectors necessary, requiring in particular new, even more radiation-hard and granular, sensors for the inner detector region. A proposal for the next generation of inner detectors is based on HV-CMOS: a new family of silicon sensors based on commercial high-voltage CMOS technology, which enables the fabrication of part of the pixel electronics inside the silicon substrate itself. The main advantages of this technology with respect to the standard silicon sensor technology are: low material budget, fast charge collection time, high radiation tolerance, low cost and operation at room temperature. A traditional readout chip is still needed to receive and organize the data from the active sensor and to handle high-level functionality such as trigger management. HV-CMOS has been designed to be compatible with both pixel and strip readout. In this paper an overview of HV2FEI4, a HV-CMOS prototype in 180 nm AMS technology, will be given. Preliminary results after neutron and X-ray irradiation are shown

    Applying eXplainable AI Techniques to Interpret Machine Learning Predictive Models for the Analysis of Problematic Internet Use among Adolescents

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    This research focusses on the potential application of artificial intelligence (AI) techniques in the analysis of behavioural addictions, specifically addressing problematic Internet use among adolescents. Using tabular data from a representative sample from Serbian high schools, the authors investigated the feasibility of employing eXplainable AI (XAI) techniques, placing special emphasis on feature selection and feature importance methods. The results indicate a successful application to tabular data, with global interpretations that effectively describe predictive models. These findings align with previous research, which confirms both relevance and accuracy. Interpretations of individual predictions reveal the impact of features, especially in cases of misclassified instances, underscoring the significance of XAI techniques in error analysis and resolution. Although AI’s influence on the medical domain is substantial, the current state of XAI techniques, although useful, is not yet advanced enough for the reliable interpretation of predictions. Nevertheless, XAI techniques play a crucial role in problem identification and the validation of AI models
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