Dual-Band Integrated Antennas for DVB-T Receivers

An overview on compact Planar Inverted-F Antennas (PIFAs) that are suitable for monitor-equipped devices is presented. In particular, high efficiency PIFAs (without any dielectric layer) with a percentage bandwidth (%BW) greater than 59% (470–862 MHz DVB-T band) are considered. In this context, two PIFA configurations are reviewed, where a dual-band feature has been obtained, in the 3300–3800 MHz (14% percentage bandwidth) WiMAX and 2400–2484 MHz (2.7% percentage bandwidth) WLAN IEEE 802.11b,g frequency bands, respectively, to also guarantee web access to on-demand services. The two PIFAs fill an overall volume of  mm3 and  mm3, respectively. They are composed of a series of branches, properly dimensioned and separated to generate the required resonances. Finally, to show the extreme flexibility of the previous two configurations, a novel dual-band L-shape PIFA has been designed. A reflection coefficient less than −6 dB and −10 dB and an antenna gain of around 2 dBi and 6.3 dBi have been obtained in the 470–862 MHz DVB-T band and the 2400–2484 MHz WLAN band, respectively. The L-shape PIFA prototype can be obtained by properly cutting and folding a single metal sheet, thus resulting in a relatively low-cost and mechanically robust antenna configuration

Exploring waste-collection fleet data: challenges in a real-world use case from multiple data providers

In the age of connected vehicles, large amounts of data can be collected while driving through a variety of on-board sensors. The information collected can be used for various types of data-driven analytics that can be of great benefit to both vehicle owners, e.g., to reduce costs by means of predictive maintenance, and to society as a whole, e.g., to optimize mobility behavior. Prior to any real-world data analysis, an investigation and characterization of the available data is of utmost importance in order to evaluate the quality and quantity of the data and to set the right expectations. In this paper, we focus on the data exploration and characterization step, which is necessary to avoid inconsistencies in the collected parameters and to enable valid, data-driven modeling. The proposed data exploration considers both the frequency of samples and their values for all monitored parameters. A specific cross-provider data comparison is performed to compare values collected for the same vehicle at the same time from different fleet monitoring data providers. The study is applied to a real-world use case with months of data from dozens of vehicles deployed in the waste collection service managed by SEA, Soluzioni Eco Ambientali, in Italy. The analyzes uncover unexpected behaviors in the measurements and lead to their early identification, bringing great benefits to the company operating the fleet by improving data collection and enabling a safe modeling phase

Open Access, Open Science, Open Society

Open Access’ main goal is not the subversion of publishers’ role as driving actors in an oligopolistic market characterised by reduced competition and higher prices. OA’s main function is to be found somewhere else, namely in the ability to subvert the power to control science’s governance and its future directions (Open Science), a power that is more often found within the academic institutions rather than outside. By decentralising and opening-up not just the way in which scholarship is published but also the way in which it is assessed, OA removes the barriers that helped turn science into an intellectual oligopoly even before an economic one. The goal of this paper is to demonstrate that Open Access is a key enabler of Open Science, which in turn will lead to a more Open Society. Furthermore, the paper argues that while legislative interventions play an important role in the top-down regulation of Open Access, legislators currently lack an informed and systematic vision on the role of Open Access in science and society. In this historical phase, other complementary forms of intervention (bottom-up) appear much more “informed” and effective. This paper, which intends to set the stage for future research, identifies a few pieces of the puzzle: the relationship between formal and informal norms in the field of Open Science and how these impact on intellectual property rights, the protection of personal data, the assessment of science and the technology employed for the communication of science

Antennas and photovoltaic panels: Toward a green Internet of Things

The perspective of a wide use of green power motivates the scientific community to study the possibility of fabricating integrated stand-alone devices. In particular, solar energy is one of the most promising renewable powers, and it is widely used in autonomous wireless communication systems. Specifically, integration of sensors and antennas in a solar panel represents a challenge for future technology. In this paper, the feasibility of a single integrated autonomous device equipped with WiFi capability is analyzed, discussing its potentiality in the framework of the Internet of Things

Electroweak effects in the B0−Bˉ0B^0-{\bar B}^0 mixing

We compute analytically the complete electroweak two-loop corrections to the $B^0-{\bar B}^0$ mixing. These corrections fix the normalization of the electroweak coupling employed in the extraction of $|V_{td}|$ and reduce the theoretical uncertainty due to higher order electroweak effects from several percent to a few parts in a thousand. If the LO result is expressed in terms of $G_\mu$ or of the $\bar{MS}$ coupling $\hat{g}(M_Z)$, the two-loop corrections are $O(1$, the exact value depending on the mass of the Higgs boson. We discuss in detail the renormalization procedure and the scheme and scale dependence, and provide practical formulas for the numerical implementation of our results. We also consider the heavy top mass expansion and show that in the case at hand it converges very slowly.Comment: LaTeX, 29 pages, 6 postscript figures include

Bayesian radiocarbon modeling and the absolute chronology of the Middle Bronze Age Thapsos facies in mainland Sicily : a view from St. Ippolito (Caltagirone)

One of the most debated and explored period of the prehistory of Sicily is the Middle Bronze Age (15th-13th century BCE), which is considered as a crucial moment for the development of local prehistoric social, economic, and cross-cultural dynamics. The local Thapsos culture is what best represents this chronological period and is characterized at some sites by theoccurrence of datable ceramic imports from the Aegean alongside their local replicas. These have helped researchers with estab-lishing a local relative chronology based indirect beacons with eastern Mediterranean contexts. However, when it comes to an independent absolute chronology for MBA context in mainland Sicily, no recent program of radiocarbon dating has been carried out so far. In this contribution, the authors devise a Bayesian model based on evidence from a stratified MBA context at St. Ippolito (Caltagirone, central-eastern Sicily) where a set of seven samples have been radiocarbon dated. The study aims to assess which part of the overall development of the MBA the analyzed context corresponds to, to absolute date the activities represented by the deposit’s layers, and to lay the basis to tentatively bracket in time the use of some associated ceramic materials.peer-reviewe

Early Hemorrhagic Transformation of Brain Infarction: Rate, Predictive Factors, and Influence on Clinical Outcome

Background and Purpose— Early hemorrhagic transformation (HT) is a complication of ischemic stroke but its effect on patient outcome is unclear. The aims of this study were to assess: (1) the rate of early HT in patients admitted for ischemic stroke, (2) the correlation between early HT and functional outcome at 3 months, and (3) the risk factors for early HT. Methods— Consecutive patients with ischemic stroke were included in this prospective study in 4 study centers. Early HT was assessed by CT examination performed at day 5±2 after stroke onset. Study outcomes were 3-month mortality or disability. Disability was assessed using a modified Rankin score (≥3 indicating disabling stroke) by neurologists unaware of the occurrence of HT in the individual cases. Outcomes in patients with and without early HT were compared by χ 2 test. Multiple logistic regression analysis was used to identify predictors for HT. Results— Among 1125 consecutive patients (median age 76.00 years), 98 (8.7%) had HT, 62 (5.5%) had hemorrhagic infarction, and 36 (3.2%) parenchymal hematoma. At 3 months, 455 patients (40.7%) were disabled or died. Death or disability was seen in 33 patients with parenchymal hematoma (91.7%), in 35 patients with hemorrhagic infarction (57.4%) as compared with 387 of the 1021 patients without HT (37.9%). At logistic regression analysis, parenchymal hematoma, but not hemorrhagic infarction, was independently associated with an increased risk for death or disability (OR 15.29; 95% CI 2.35 to 99.35). At logistic regression analysis, parenchymal hematoma was predicted by large lesions (OR 12.20, 95% CI 5.58 to 26.67), stroke attributable to cardioembolism (OR 5.25; 95% CI 2.27 to 12.14) or to other causes (OR 6.77; 95% CI 1.75 to 26.18), high levels of blood glucose (OR 1.01; 95% CI 1.00 to 1.01), and thrombolytic treatment (OR 3.54, 95% CI 1.04 to 11.95). Conclusions— Early HT occurs in about 9% of patients. Parenchymal hematoma, seen in about 3% of patients, is associated with an adverse outcome. Parenchymal hematoma was predicted by large lesions attributable to cardioembolism or other causes, high blood glucose, and treatment with thrombolysis

Measurement of the gluon PDF at small x with neutrino telescopes

We analyze the possibility that neutrino telescopes may provide an experimental determination of the slope lambda of the gluon distribution in the proton at momentum fractions x smaller than the accelerator reach. The method is based on a linear relation between lambda and the spectral index (slope) of the down-going atmospheric muon flux above 100 TeV, for which there is no background. Considering the uncertainties in the charm production cross section and in the cosmic ray composition, we estimate the error on the measurement of lambda through this method, excluding the experimental error of the telescopes, to be ~ +/- 0.2Comment: 16 pages with 16 figures - new version, comments added, same results and figure