127 research outputs found

    Non-autonomous stochastic evolution equations and applications to stochastic partial differential equations

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    In this paper we study the following non-autonomous stochastic evolution equation on a UMD Banach space EE with type 2, {equation}\label{eq:SEab}\tag{SE} {{aligned} dU(t) & = (A(t)U(t) + F(t,U(t))) dt + B(t,U(t)) dW_H(t), \quad t\in [0,T], U(0) & = u_0. {aligned}. {equation} Here (A(t))t∈[0,T](A(t))_{t\in [0,T]} are unbounded operators with domains (D(A(t)))t∈[0,T](D(A(t)))_{t\in [0,T]} which may be time dependent. We assume that (A(t))t∈[0,T](A(t))_{t\in [0,T]} satisfies the conditions of Acquistapace and Terreni. The functions FF and BB are nonlinear functions defined on certain interpolation spaces and u0∈Eu_0\in E is the initial value. WHW_H is a cylindrical Brownian motion on a separable Hilbert space HH. Under Lipschitz and linear growth conditions we show that there exists a unique mild solution of \eqref{eq:SEab}. Under assumptions on the interpolation spaces we extend the factorization method of Da Prato, Kwapie\'n, and Zabczyk, to obtain space-time regularity results for the solution UU of \eqref{eq:SEab}. For Hilbert spaces EE we obtain a maximal regularity result. The results improve several previous results from the literature. The theory is applied to a second order stochastic partial differential equation which has been studied by Sanz-Sol\'e and Vuillermot. This leads to several improvements of their result.Comment: Accepted for publication in Journal of Evolution Equation

    2019 Italian Society of Cardiology census on telemedicine in cardiovascular disease : a report from the working group on telecardiology and informatics

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    Background The aim of this study was to assess by a census supported by the Italian Society of Cardiology (Societ\ue0 Italiana di Cardiologia, SIC) the present implementation of telemedicine in the field of cardiovascular disease in Italy. Methods A dedicated questionnaire was sent by email to all the members of the SIC: data on telemedicine providers, service provided, reimbursement, funding and organisational solutions were collected and analysed. Results Reported telemedicine activities were mostly stable and public hospital based, focused on acute cardiovascular disease and prehospital triage of suspected acute myocardial infarction (prehospital ECG, always interpreted by a cardiologist and not automatically reported by computerised algorithms). Private companies delivering telemedicine services in cardiology (ECGs, ambulatory ECG monitoring) were also present. In 16% of cases, ECGs were also delivered through pharmacies or general practitioners. ICD/CRT-D remote control was performed in 42% of cases, heart failure patient remote monitoring in 37% (21% vital parameters monitoring, 32% nurse telephone monitoring). Telemedicine service was public in 74% of cases, paid by the patient in 26%. About half of telemedicine service received no funding, 17% received State and/or European Union funding. Conclusions Several telemedicine activities have been reported for the management of acute and chronic cardiovascular disease in Italy. The whole continuum of cardiovascular disease is covered by telemedicine solutions. A periodic census may be useful to assess the implementation of guidelines recommendations on telemedicine

    Regularity of Ornstein-Uhlenbeck processes driven by a L{\'e}vy white noise

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    The paper is concerned with spatial and time regularity of solutions to linear stochastic evolution equation perturbed by L\'evy white noise "obtained by subordination of a Gaussian white noise". Sufficient conditions for spatial continuity are derived. It is also shown that solutions do not have in general \cadlag modifications. General results are applied to equations with fractional Laplacian. Applications to Burgers stochastic equations are considered as well.Comment: This is an updated version of the same paper. In fact, it has already been publishe

    JOYCE: JĂŒlich Observatory for cloud evolution

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    The JĂŒlich Observatory for Cloud Evolution (JOYCE), located at Forschungszentrum JĂŒlich in the most western part of Germany, is a recently established platform for cloud research. The main objective of JOYCE is to provide observations, which improve our understanding of the cloudy boundary layer in a midlatitude environment. Continuous and temporally highly resolved measurements that are specifically suited to characterize the diurnal cycle of water vapor, stability, and turbulence in the lower troposphere are performed with a special focus on atmosphere–surface interaction. In addition, instruments are set up to measure the micro- and macrophysical properties of clouds in detail and how they interact with different boundary layer processes and the large-scale synoptic situation. For this, JOYCE is equipped with an array of state-of-the-art active and passive remote sensing and in situ instruments, which are briefly described in this scientific overview. As an example, a 24-h time series of the evolution of a typical cumulus cloud-topped boundary layer is analyzed with respect to stability, turbulence, and cloud properties. Additionally, we present longer-term statistics, which can be used to elucidate the diurnal cycle of water vapor, drizzle formation through autoconversion, and warm versus cold rain precipitation formation. Both case studies and long-term observations are important for improving the representation of clouds in climate and numerical weather prediction models

    An Experimentalist's View of Neutrino Oscillations

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    Neutrinos, and primarily neutrino oscillations, have undoubtedly been one of the most exciting topics in the field of high-energy physics over the past few years. The existence of neutrino oscillations would require an extension of the currently accepted description of sub-nuclear phenomena beyond the Standard Model. Compelling evidence of new physics, which seems to be pointing towards neutrino oscillations, is coming from the solar neutrino deficit and from the atmospheric neutrino anomaly. More controversial effects have been observed with artificially produced neutrinos. The present experimental status of neutrino oscillations is reviewed, as well as the planned future experimental programme, which, it is hoped, will solve most of the outstanding puzzles.Comment: 64 pages, 29 figures, to be published in Intern. J. Mod. Phys. A (2001

    Neutrino oscillation physics at an upgraded CNGS with large next generation liquid Argon TPC detectors

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    The determination of the missing Ue3U_{e3} element (magnitude and phase) of the PMNS neutrino mixing matrix is possible via the detection of \numu\to\nue oscillations at a baseline LL and energy EE given by the atmospheric observations, corresponding to a mass squared difference E/L∌Δm2≃2.5×10−3eV2E/L \sim \Delta m^2\simeq 2.5\times 10^{-3} eV^2. While the current optimization of the CNGS beam provides limited sensitivity to this reaction, we discuss in this document the physics potential of an intensity upgraded and energy re-optimized CNGS neutrino beam coupled to an off-axis detector. We show that improvements in sensitivity to Ξ13\theta_{13} compared to that of T2K and NoVA are possible with a next generation large liquid Argon TPC detector located at an off-axis position (position rather distant from LNGS, possibly at shallow depth). We also address the possibility to discover CP-violation and disentangle the mass hierarchy via matter effects. The considered intensity enhancement of the CERN SPS has strong synergies with the upgrade/replacement of the elements of its injector chain (Linac, PSB, PS) and the refurbishing of its own elements, envisioned for an optimal and/or upgraded LHC luminosity programme.Comment: 37 pages, 20 figure
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