774 research outputs found
Synthesizing SystemC Code from Delay Hybrid CSP
Delay is omnipresent in modern control systems, which can prompt oscillations
and may cause deterioration of control performance, invalidate both stability
and safety properties. This implies that safety or stability certificates
obtained on idealized, delay-free models of systems prone to delayed coupling
may be erratic, and further the incorrectness of the executable code generated
from these models. However, automated methods for system verification and code
generation that ought to address models of system dynamics reflecting delays
have not been paid enough attention yet in the computer science community. In
our previous work, on one hand, we investigated the verification of delay
dynamical and hybrid systems; on the other hand, we also addressed how to
synthesize SystemC code from a verified hybrid system modelled by Hybrid CSP
(HCSP) without delay. In this paper, we give a first attempt to synthesize
SystemC code from a verified delay hybrid system modelled by Delay HCSP
(dHCSP), which is an extension of HCSP by replacing ordinary differential
equations (ODEs) with delay differential equations (DDEs). We implement a tool
to support the automatic translation from dHCSP to SystemC
A Low-Complexity Decision Feedforward Equalizer Architecture for High-Speed Receivers on Highly Dispersive Channels
This paper presents an improved decision feedforward equalizer (DFFE) for high speed receivers in the presence of highly dispersive channels. This decision-aided equalizer technique has been recently proposed for multigigabit communication receivers, where the use of parallel processing is mandatory. Well-known parallel architectures for the typical decision feedback equalizer (DFE) have a complexity that grows exponentially with the channel memory. Instead, the new DFFE avoids that exponential increase in complexity by using tentative decisions to cancel iteratively the intersymbol interference (ISI). Here, we demostrate that the DFFE not only allows to obtain a similar performance to the typical DFE but it also reduces the compelxity in channels with large memory. Additionally, we propose a theoretical approximation for the error probability in each iteration. In fact, when the number of iteration increases, the error probability in the DFFE tends to approach the DFE. These benefits make the DFFE an excellent choice for the next generation of high-speed receivers.Fil: Pola, Ariel Luis. Universidad Nacional de Cordoba. Facultad de Cs.exactas Fisicas y Naturales. Departamento de Electronica. Laboratorio de Comunicaciones; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas; ArgentinaFil: Cousseau, Juan Edmundo. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico BahÃa Blanca. Instituto de Investigación En IngenierÃa Eléctrica; Argentina. Universidad Nacional del Sur; ArgentinaFil: Agazzi, Oscar E.. Irvine Center Drive. ClariPhy Communications; Estados UnidosFil: Hueda, Mario Rafael. Universidad Nacional de Cordoba. Facultad de Cs.exactas Fisicas y Naturales. Departamento de Electronica. Laboratorio de Comunicaciones; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas; Argentin
Pulsed Current Effect on the Hard Anodizing of an AlSi10Mg Aluminum Alloy Obtained via Additive Manufacturing
The hard anodizing treatments of cast Al-Si alloys are notoriously difficult. Indeed, their microstructural features hinder the growth of a uniform, compact, and defect-free anodic oxide. In this paper, AlSi10Mg samples, produced via Gravity Casting (GC) and Additive Manufacturing, i.e., Laser Powder Bed Fusion (L-PBF), were hard anodized in a sulfuric acid bath, in order to verify how the particular microstructure obtained via L-PBF affects the thickness, hardness, compactness, and defectiveness of the anodic oxide. Moreover, for the first time, Pulsed Direct Current (PDC) procedures were used to perform the hard anodizing treatments on additively manufactured AlSi10Mg alloy. Several combinations of temperature and electrical parameters, i.e., current density, frequency, and Duty Cycle, were tested. The anodized samples were characterized through optical microscopy analysis, Scanning Electron Microscopy (SEM) analysis, and accelerated corrosion tests, i.e., Potentiodynamic Polarization (POL) and Electrochemical Impedance Spectroscopy (EIS) measurements. The PDC procedures allowed improvement of the compromise between evenness, compactness, and defectiveness. Among the attempted PDC procedures, a specific combination of electrical parameters and temperature allowed the best results to be obtained, i.e., the highest hardness and the lowest volumetric expansion values without compromising the oxide quality rating and the corrosion resistance behavior. However, none of the attempted PCD strategies allowed the hardness values obtained on samples produced via GC to be reached
Sustainable Co-Design with Older People: The case of a Public Restorative Garden in Milan (Italy)
The demographic aging and the evolution of lifestyles require new strategies to promote the well-being and active aging of elderly. Active aging depends on many factors: some of these are
related to objective data such as physical environment, others are personal elements; it is important to improve environmental physical factors to encourage personal attitudes to the green spaces in use.
To design a small sustainable restorative green space in Milan, Italy, restorative garden design criteria are summarized in the first section of the paper and both social and environmental sustainability are considered. The methodology section describes the co-design process and how it was applied to include dierent older user groups in the design of the area. In the results section authors apply a taxonomy based on the four properties of restorative settings according to the Attention Restoration Theory by Kaplan (compatibility, being away, extent, fascination): this provides a unified system to classify users\u2019 expectations and to describe the final project. The proposed co-design process combines social and environmental sustainability, as it provides designers an insight about the user\u2019s experience in nature. Such information can be fruitfully integrated with professional competences about comfort aspects and environmental protection in order to improve the whole design project
Equivalence of switching linear systems by bisimulation
A general notion of hybrid bisimulation is proposed for the class of switching linear systems. Connections between the notions of bisimulation-based equivalence, state-space equivalence, algebraic and input–output equivalence are investigated. An algebraic characterization of hybrid bisimulation and an algorithmic procedure converging in a finite number of steps to the maximal hybrid bisimulation are derived. Hybrid state space reduction is performed by hybrid bisimulation between the hybrid system and itself. By specializing the results obtained on bisimulation, also characterizations of simulation and abstraction are derived. Connections between observability, bisimulation-based reduction and simulation-based abstraction are studied.\ud
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Correlation between magnetic and transport properties in nanocrystalline Fe thin films: A grain-boundary magnetic disorder effect
We report on transport and magnetic measurements of islanded Fe(110) thin films. The electrical resistivity exhibits an anomalous increase at low temperatures, which disappears under the action of a magnetic field. Since such an anomaly completely disappears under the action of a magnetic field, it is inferred that it originates from spin-dependent scattering. We interpret the strong changes in the spin-dependent scattering in our films to be due to a low-temperature spin freezing of the island boundary magnetic regions that impedes ferromagnetic exchange between islands. A consequence of this magnetic behavior is the random arrangement of the individual magnetization, determined by the magnetocrystalline anisotropy of each island, resulting in an increase of the resistivity below the freezing temperature.Z.S. and J.L.M. acknowledge the Comunidad de Madrid for financial support. Work was performed under the financial support of the Comunidad de Madrid and the Spanish Commission of Science and Technology.Peer reviewe
Venous thromboembolism in patients with COVID-19: Systematic review and meta-analysis
Background: Venous thromboembolism (VTE) may complicate the course of Coronavirus Disease 2019 (COVID-19). Objectives: To evaluate the incidence of VTE in patients with COVID-19. Methods: MEDLINE, EMBASE, and PubMed were searched up to 24th June 2020 for studies that evaluated the incidence of VTE, including pulmonary embolism (PE) and/or deep vein thrombosis (DVT), in patients with COVID-19. Pooled proportions with corresponding 95% confidence intervals (CI) and prediction intervals (PI) were calculated by random-effect meta-analysis. Results: 3487 patients from 30 studies were included. Based on very low-quality evidence due to heterogeneity and risk of bias, the incidence of VTE was 26% (95% PI, 6%–66%). PE with or without DVT occurred in 12% of patients (95% PI, 2%–46%) and DVT alone in 14% (95% PI, 1%–75%). Studies using standard algorithms for clinically suspected VTE reported PE in 13% of patients (95% PI, 2%–57%) and DVT in 6% (95% PI, 0%–60%), compared to 11% (95% PI, 2%–46%) and 24% (95% PI, 2%–85%) in studies using other diagnostic strategies or patient sampling. In patients admitted to intensive care units, VTE occurred in 24% (95% PI, 5%–66%), PE in 19% (95% PI, 6%–47%), and DVT alone in 7% (95% PI, 0%–69%). Corresponding values in general wards were respectively 9% (95% PI, 0%–94%), 4% (95% PI, 0%–100%), and 7% (95% CI, 1%–49%). Conclusions: VTE represents a frequent complication in hospitalized COVID-19 patients and often occurs as PE. The threshold for clinical suspicion should be low to trigger prompt diagnostic testing
PREDICTORS OF RENAL AND PATIENT OUTCOMES IN ATHEROEMBOLIC RENAL DISEASE: A PROSPECTIVE STUDY.
Characterization of a Be(p,xn) neutron source for fission yields measurements
We report on measurements performed at The Svedberg Laboratory (TSL) to
characterize a proton-neutron converter for independent fission yield studies
at the IGISOL-JYFLTRAP facility (Jyv\"askyl\"a, Finland). A 30 MeV proton beam
impinged on a 5 mm water-cooled Beryllium target. Two independent experimental
techniques have been used to measure the neutron spectrum: a Time of Flight
(TOF) system used to estimate the high-energy contribution, and a Bonner Sphere
Spectrometer able to provide precise results from thermal energies up to 20
MeV. An overlap between the energy regions covered by the two systems will
permit a cross-check of the results from the different techniques. In this
paper, the measurement and analysis techniques will be presented together with
some preliminary results.Comment: 3 pages, 3 figures, also submitted as proceedings of the
International Conference on Nuclear Data for Science and Technology 201
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