Search results for "RESTOR"
showing 10 items of 670 documents
HST observation of the inner coma of 2060 chiron
1995
Abstract The analysis of persistent comae of very large and distant comets allows us to infer the poorly known physical properties of dust and icy grains produced beyond Jupiter. Chiron is particularly interesting because Fulle ( Astron. Astrophys. 282 , 980–988; 1994) has shown that the strong asymmetricity of its coma (West, Astron. Astrophys. 241 , 635–645 1991) allows us to infer rotational properties of Chiron's nucleus. In this paper we report the observation of the asymmetric inner coma of Chiron from the analysis of 44 images of Chiron and eight images of a standard star available from the HST archive. The images were taken during February/March 1993, when Ch iron was 9.3 AU from th…
General Hartree–Fock method and symmetry breaking in quantum dots
2010
Interaction and correlation effects in quantum dots play a fundamental role in defining both their equilibrium and transport properties. Numerical methods are commonly employed to study such systems. In this paper we present a two-step approach in which a Hartree-Fock method, with explicit symmetry breaking, is followed by a projection technique for symmetry restoration. Three different Hartree-Fock implementations, with an increasing degree of symmetry breaking, are introduced and applied to the study of interacting planar dots with N = 3 and 6, electrons in the presence of a perpendicular magnetic field. In addition to the restricted and unrestricted techniques already employed for quantu…
In-medium modifications of the pi pi interaction in photon-induced reactions
2002
Differential cross sections of the reactions $(\gamma,\pi^\circ\pi^\circ)$ and $(\gamma,\pi^\circ\pi^++\pi^\circ\pi^-)$ have been measured for several nuclei ($^1$H,$^{12}$C, and $^{\rm nat}$Pb) at an incident-photon energy of $E_{\gamma}$=400-460 MeV at the tagged-photon facility at MAMI-B using the TAPS spectrometer. A significant nuclear-mass dependence of the $\pi\pi$ invariant-mass distribution is found in the $\pi^\circ\pi^\circ$ channel. This dependence is not observed in the $\pi^\circ\pi^{+/-}$ channel and is consistent with an in-medium modification of the $\pi\pi$ interaction in the $I$=$J$=0 channel. The data are compared to $\pi$-induced measurements and to calculations within …
Il recupero e la manutenzione della Gipsoteca di scultura antica del Dipartimento Culture e Società dell’Università degli Studi di Palermo
2018
The Department Cultures and Societies of the University of Palermo in Italy owns a collection of forty plaster casts of ancient sculpture, dating back to the age of the academic teaching of Antonino Salinas (1841- 1914). In the intentions of the great archaeologist of Palermo, the plaster cast collection was of unavoidable help to teach classical art, in line with the contemporary usages of the Italian and foreign Universities. In the following decades, as everywhere, the collection progressively ended up by losing its central position in the study of archaeology, according to the transformations and the developments of the discipline over the twentieth century. In the latest times, all the…
Total Variation Based Image Restoration
2004
For the purpose of image restoration the process of image formation can be modeled in a first approximation by the formula [207] $$ {u_d} = Q\{ II(k*u) + n\} , $$ (1.1) where u represents the photonic flux k is the point spread function of the optical-captor joint apparatus П is a sampling operator, i.e., a Dirac comb supported by the centers of the matrix of digital sensors, n represents a random perturbation due to photonic or electronic noise, and Qis a uniform quantization operator mapping ℝ to a discrete interval of values, typically [0, 255].
Multiframe image restoration in the presence of noisy blur kernel
2009
We wish to recover an original image u from several blurry-noisy versions f k , called frames. We assume a more severe degradation model, in which the image u has been blurred by a noisy (stochastic) point spread function. We consider the problem of restoring the degraded image in a variational framework. Since the recovery of u from one single frame f is a highly ill-posed problem, we formulate two minimization problems based on the multiframe approach proposed for image super-resolution by Marquina-Osher [13]. Several experimental results for image restoration are shown, illustrating that the proposed models give visually satisfactory results.
Variational multiframe restoration of images degraded by noisy (stochastic) blur kernels
2013
This article introduces and explores a class of degradation models in which an image is blurred by a noisy (stochastic) point spread function (PSF). The aim is to restore a sharper and cleaner image from the degraded one. Due to the highly ill-posed nature of the problem, we propose to recover the image given a sequence of several observed degraded images or multiframes. Thus we adopt the idea of the multiframe approach introduced for image super-resolution, which reduces distortions appearing in the degraded images. Moreover, we formulate variational minimization problems with the robust (local or nonlocal) L^1 edge-preserving regularizing energy functionals, unlike prior works dealing wit…
Civil Justice in the Global Current Society
2017
The monopolization of the process model within the framework of Civil Justice has been a reality, especially in continental court systems, and found its raison d'etre in the social, political, economic and legal history of civilization. Civil justice was identified with the Process, even though it was not the only way to achieve it; but it was understood as the best one possible. This model of conflict resolution appeared as a static approach, linked to the idea of "public service", which is technically complex with certain formalities. The Process was progressively considered to be a conquest of civilization. This procedural model has been providing a way for the pacification of society, i…
Dynamic Animal Populations in Managed Forests: Species Ecological Requirements and Sustainable Harvesting
2015
Forest management has altered forested environments and provoked stress to many natural habitats and biodiversity. The goal of biodiversity management is the long-term persistence of populations in human-modified environments. We demonstrate a spatio-temporal modeling approach to address the relationship between various management objectives and population persistence in the long-term in a commercial forest landscape. We used the flying squirrel (Pteromys volans), the three-toed woodpecker (Picoides tridactylus) and the long-tailed tit (Aegithalos caudatus) as example species. They are all forest species but they have distinctly different habitat requirements. In the model, forest growth, f…
The effect of dentine pre-treatment using bioglass and/or polyacrylic acid on the interfacial characteristics of resin-modified glass ionomer cements.
2018
Objective To evaluate the effect of load-cycle aging and/or 6 months artificial saliva (AS) storage on bond durability and interfacial ultramorphology of resin-modified glass ionomer cement (RMGIC) applied to dentine air-abraded using Bioglass 45S5 (BAG) with/without polyacrylic acid (PAA) conditioning.Methods RMGIC (Ionolux, VOCO) was applied onto human dentine specimens prepared with silicon-carbide abrasive paper or air-abraded with BAG with or without the use of PAA conditioning. Half of bonded-teeth were submitted to load cycling (150,000 cycles) and half immersed in deionised water for 24 h. They were cut into matchsticks and submitted immediately to microtensile bond strength (μTBS) …