Search results for "Map"

Recovery of time-dependent coefficients from boundary data for hyperbolic equations

2019

We study uniqueness of the recovery of a time-dependent magnetic vector-valued potential and an electric scalar-valued potential on a Riemannian manifold from the knowledge of the Dirichlet to Neumann map of a hyperbolic equation. The Cauchy data is observed on time-like parts of the space-time boundary and uniqueness is proved up to the natural gauge for the problem. The proof is based on Gaussian beams and inversion of the light ray transform on Lorentzian manifolds under the assumptions that the Lorentzian manifold is a product of a Riemannian manifold with a time interval and that the geodesic ray transform is invertible on the Riemannian manifold.

Estimation of Purkinje trees from electro-anatomical mapping of the left ventricle using minimal cost geodesics

2015

The electrical activation of the heart is a complex physiological process that is essential for the understanding of several cardiac dysfunctions, such as ventricular tachycardia (VT). Nowadays, patient-specific activation times on ventricular chambers can be estimated from electro-anatomical maps, providing crucial information to clinicians for guiding cardiac radio-frequency ablation treatment. However, some relevant electrical pathways such as those of the Purkinje system are very difficult to interpret from these maps due to sparsity of data and the limited spatial resolution of the system. We present here a novel method to estimate these fast electrical pathways from the local activati…

Comparison theorems for the volume of a geodesic ball with a product of space forms as a model

1995

We prove two comparison theorems for the volume of a geodesic ball in a Riemannian manifold taking as a model a geodesic ball in a product of two space forms.

Red geodésica de 1er. orden y nivelaciones de precisión de España

Llegenda

Illustrazione di una carta geografica del 1455, e delle notizie, che in quel tempo aveansi dell' Antillia

1812

Sign.: [1]-[5]4, [6]3 Notes a peu de pàg.

L'isole piu famose del mondo / descritte da Thomaso Porcacchi da Castiglione aretino e intagliate da Girolamo Porro padovano con l'Aggiunta di molte …

1575

Sig. a-b6, c2, A-R6 Les il. calc. - Capitals grav. xil. Port. arquitectònica. - Text amb postil·les marginals. - Reclams. - Registre. - Errates de pag.

Modelling the spatial-temporal progression of the 2009 A/H1N1 influenza pandemic in Chile

2016

A spatial-temporal transmission model of 2009 A/H1N1 pandemic influenza across Chile, a country that spans a large latitudinal range, is developed to characterize the spatial variation in peak timing of that pandemic as a function of local transmission rates, spatial connectivity assumptions for Chilean regions, and the putative location of introduction of the novel virus into the country. Specifically, a metapopulation SEIR (susceptible-exposed-infected-removed) compartmental model that tracks the transmission dynamics of influenza in 15 Chilean regions is calibrated. The model incorporates population mobility among neighboring regions and indirect mobility to and from other regions via th…

Borders on the old maps of Jizera Mountain

2019

Abstract Old maps, mainly from the period between 1890 and 1940, have been collected in the framework of the project “Old Maps of the Jizera Mountains”. These maps provide us with a complex picture, mainly of tourism, in this currently Czech–Polish territory. The territory of the Jizera Mountains was inhabited mainly by a German-speaking population on both sides of the border until 1945. Yet it is interesting to examine how the border between the two states – in those times Czechoslovakia and Germany, now Czechia and Poland – was illustrated on these old maps. This article argues that the border was not perceived as a barrier as such until later on, mainly due to the ethnic change in the bo…

Geobotanical approach to detect land-use change of a Mediterranean landscape: a case study in Central-Western Sicily

2018

A landscape is a palimpsest of the interactions between human activities and ecological dynamics. In an interdisciplinary perspective of dialogue between the ‘Two Cultures’ (Natural Sciences and Humanities), a study of a rural area has been carried out through a reading of plant ecosystems as signs of human impact. The purpose of this paper—as part of the project ‘Harvesting Memories’: Ecology and landscape archaeology of Castro/Giardinallo Valley and Mt. Barrau district (Corleone, Palermo, Sicily)—is to analyse the formative-processes of a Sicilian rural landscape and its changes in the last century. A key element in the reconstruction of the formation of the present landscape is the serie…

Understanding the Effects of Fires on Surface Evapotranspiration Patterns Using Satellite Remote Sensing in Combination with an Energy Balance Model

2011

Forest fires are highly destructive for nature, affecting the landscape, the natural cicle of the vegetation, and the structure and functioning of ecosystems. Beyond that, they also provoke changes in the local and regional meteorology, and particularly in the surface energy flux patterns. In a fire-affected area, changes in the ecosystem structure and species composition modify the evapotranspiration (LE) and the rest of the terms involved in the energy balance equation. Besides, these changes in the local energy balance may persist for decades (Randerson et al., 2006). There is an increasing concern among the scientific community about the effect of forest fires on climate change at this …