117,634 research outputs found
Erratum to: Effect of moderate red wine intake on cardiac prognosis after recent acute myocardial infarction of subjects with Type 2 diabetes mellitus (Diabetic Medicine, (2006), 23, 9, (974-981), 10.1111/j.1464-5491.2006.01886.x)
No full textIn an article by Marfella et al, the author name C. Saron is incorrect and should be listed as C. Sardu. Therefore the correct author list is: R. Marfella, F. Cacciapuoti, M. Siniscalchi, F. C. Sasso, F. Marchese, F. Cinone, E. Musacchio, M. A. Marfella, L. Ruggiero, G. Chiorazzo, D. Liberti, G. Chiorazzo, G. F. Nicoletti, C. Sardu, F. D'Andrea, C. Ammendola, M. Verza and L. Coppola.In an article by Marfella et al, the author name C. Saron is incorrect and should be listed as C. Sardu. Therefore the correct author list is: R. Marfella, F. Cacciapuoti, M. Siniscalchi, F. C. Sasso, F. Marchese, F. Cinone, E. Musacchio, M. A. Marfella, L. Ruggiero, G. Chiorazzo, D. Liberti, G. Chiorazzo, G. F. Nicoletti, C. Sardu, F. D'Andrea, C. Ammendola, M. Verza and L. Coppola
The semi-classical limit with a delta-prime potential
No full textWe consider the quantum evolution e(-it/)((h) over barH beta)psi((h) over bar )(xi)of a Gaussian coherent state psi((h) over bar)(xi) is an element of L-2(R) localized close to the classical state xi (q, p) is an element of R-2, where H-beta denotes a self-adjoint realization of the formal Hamiltonian -(h) over bar (2)/2m d(2)/dx(2) + beta delta(0)' with delta(0)' the derivative of Dirac's delta distribution at x = 0 and beta a real parameter. We show that in the semi-classical , limit such a quantum evolution can be approximated (with respect to the L-2(R)-norm, uniformly for any t is an element of R away from the collision time) by e(i/)((h) over bar At) e(itLB )phi((h) over bar)(x), where A(t) = p(2)t/2m, phi((h) over bar)(x)(xi) := psi((h) over bar)(xi)(x) and L-B is a suitable self-adjoint extension of the restriction to C-c(infinity)(M-0), M-0 := {(q, p) is an element of R-2 vertical bar q not equal 0}, of (-i times) the generator of the free classical dynamics. While the operator L-B here utilized is similar to the one appearing in our previous work [C. Cacciapuoti, D. Fermi and A. Posilicano, The semi-classical limit with a delta potential, Ann. Mat. Pura Appl. 200 (2021) 453-489], in the present case the approximation gives a smaller error: it is of order (h) over bar (7/2)(-lambda), 0 < lambda < 1/2, whereas it turns out to be of order (h) over bar (3/2-lambda), 0 < lambda < 3/2, for the delta potential. We also provide similar approximation results for both the wave and scattering operators
Model Reduction in space and time for ab initio decomposition of 4D Variational Data Assimilation problems
No full textWe present an innovative approach for solving time dependent Four Dimensional Variational Data Assimilation (4D VAR DA) problems. The proposed approach performs a decomposition of the whole physical domain, i.e. both along spatial and temporal directions; a reduction in space and time of both the Partial Differential Equations-based model and the Data Assimilation functional; finally it uses a modified regularization functional describing restricted 4D VAR DA problems on the domain decomposition. Innovation mainly lies in the introduction ab initio, i.e. on the numerical model – of a domain decomposition approach in space and time joining the idea of Schwarz's method and Parallel in Time (PinT)–based approaches. We provide the numerical framework of this method including convergence analysis and error propagation. A validation analysis is performed discussing computational results on a case study relying on Shallow Water Equations. © 2020 IMAC
A note on domain decomposition approaches for solving 3D variational data assimilation models
No full textData assimilation (DA) is a methodology for combining mathematical models simulating complex systems (the background knowledge) and measurements (the reality or observational data) in order to improve the estimate of the system state (the forecast). The DA is an inverse and ill posed problem usually used to handle a huge amount of data, so, it is a big and computationally expensive problem. In the present work we prove that the functional decomposition of the 3D variational data assimilation (3D Var DA) operator, previously introduced by the authors, is equivalent to apply multiplicative parallel Schwarz (MPS) method, to the Euler–Lagrange equations arising from the minimization of the data assimilation functional. It results that convergence issues as well as mesh refininement techniques and coarse grid correction—issues of the functional decomposition not previously addressed—could be employed to improve performance and scalability of the 3D Var DA functional decomposition in real cases
Widely-linear versus linear blind multiuser detection with subspace-based channel estimation: finite sample-size effects
No full textIn a recent paper [A. S. Cacciapuoti et al., “Finite-
Sample Performance Analysis of Widely Linear Multiuser
Receivers in DS-CDMA Systems, IEEE TRANSACTIONS ON SIGNAL PROCESSING, vol. 56, no. 4, pp. 1572–1588, Apr. 2008], we presented the finite-sample theoretical performance comparison between linear (L) and widely linear (WL) minimum output-energy (MOE) receivers for direct-sequence code-division multiple-access (DS-CDMA) systems, worked out under the assumption that the channel impulse response of the desired user is exactly known. The main scope of this paper is to extend such an analysis, taking into
account not only autocorrelation matrix (ACM) estimation effects, but also the accuracy of subspace-based blind channel estimation (CE). We aim to answer the two following questions: Which of the two estimation processes (ACM or CE) is the main source of degradation when implementing the receivers on the basis of a finite sample-size? Compared with the L-MOE one, is the finite-sample WL-MOE receiver with blind CE capable of achieving the performance gains predicted by the theory? To this goal, simple and easily interpretable formulas are developed for the signal-to-interference-
plus-noise ratio (SINR) at the output of the L- and WL-MOE
receivers with blind CE, when they are implemented using either the sample ACM or its eigendecomposition. In addition, the derived formulas, which are validated by simulations, allow one to recognize and discuss interesting tradeoffs between the main parameters of the DS-CDMA system
S-Adenosyl-L-Methionine Overcomes uL3-Mediated Drug Resistance in p53 Deleted Colon Cancer Cells
No full textPurpose: In order to study novel therapeutic approaches taking advantage of natural compounds showing anticancer and anti-proliferative effects, we focused our interest on S-adenosyl-l-methionine, a naturally occurring sulfur-containing nucleoside synthesized from adenosine triphosphate and methionine by methionine adenosyltransferase, and its potential in overcoming drug resistance in colon cancer cells devoid of p53. Results: In the present study, we demonstrated that S-adenosyl-l-methionine overcomes uL3-mediated drug resistance in p53 deleted colon cancer cells. In particular, we demonstrated that S-adenosyl-l-methionine causes cell cycle arrest at the S phase; inhibits autophagy; augments reactive oxygen species; and induces apoptosis in these cancer cells. Conclusions: Results reported in this paper led us to propose S-adenosyl-l-methionine as a potential promising agent for cancer therapy by examining p53 and uL3 profiles in tumors to yield a better clinical outcomes
Combined Cycle Power Regulation Problems in a Liberalized Market: Experimental and Energetic Analysis, Thermo-dynamic Simulation
No full textThis paper reports the experimental analysis and numerical performance of a 760 MWe Combined Cycle Gas-Steam Power Plant, built in Sparanise (ITALY) and went into service in September 2007. This Plant fills the problem of Frequency Regulation in the restructured Italian power system which, following the European deregulating process, has been moving from a vertically integrated structure to a new scenario, with several private hold companies competing on the generation side. The new legislation revealed a number of technical and economic issues for Electric Combined Cycle Power Plants, designed to reach out to a maximum efficiency in the operation at the nominal point. For the partial evaluation of these aspects has been carried out an experimental energetic analysis of current performance and, on the basis of this, a thermodynamic simulation tool has been developed to identify the combinations of control parameters designed to maximize the overall performance and to evaluate different layout system solutions. An application of this tool has been performed to evaluate the effect of the Inlet Fogging Technique on the global efficiency
A scalable Kalman Filter algorihm: trustworthy analysis on constrained least square model
No full textKalman filter (KF) is one of the most important and common estimation algorithms. We introduce an innovative designing of Kalman filter algorithm based on domain decomposition (we call it DD‐KF). DD‐KF involves decomposition of the whole computational problem, partitioning of the solution and a slight modification of KF algorithm allowing a correction at run‐time of local solutions. The resulted parallel algorithm consists of concurrent copies of KF algorithm, each one requiring the same amount of computations on each subdomain and an exchange of boundary conditions between adjacent subdomains. Main advantage of this approach is that it can be potentially applied in a moderately nonintrusive manner to existing codes for tracking and controlling systems in location, navigation, in computer graphics and in much more state estimation problems. To highlight the capability of DD‐KF of exploiting the computing power provided by future designs of microprocessors based on multi/many‐cores CPU/GPU technologies, we consider DD both at physical core level and at microprocessor level and we discuss scalability of DD‐KF algorithm at coarse and fine grained level. Throughout the present work, we derive and discuss DD‐KF algorithm for solving constrained least square model, which underlies any data sampling and estimation problem
Post-necrotic left ventricular dysfunction in diabetes mellitus: effects of Trimetazidine
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