Application of the χ2\chi^2 principle and unbiased predictive risk estimator for determining the regularization parameter in 3D focusing gravity inversion

The $\chi^2$ principle and the unbiased predictive risk estimator are used to determine optimal regularization parameters in the context of 3D focusing gravity inversion with the minimum support stabilizer. At each iteration of the focusing inversion the minimum support stabilizer is determined and then the fidelity term is updated using the standard form transformation. Solution of the resulting Tikhonov functional is found efficiently using the singular value decomposition of the transformed model matrix, which also provides for efficient determination of the updated regularization parameter each step. Experimental 3D simulations using synthetic data of a dipping dike and a cube anomaly demonstrate that both parameter estimation techniques outperform the Morozov discrepancy principle for determining the regularization parameter. Smaller relative errors of the reconstructed models are obtained with fewer iterations. Data acquired over the Gotvand dam site in the south-west of Iran are used to validate use of the methods for inversion of practical data and provide good estimates of anomalous structures within the subsurface

Challenging Platonic Erôs: The Role of Thumos and Philotimia in Love

International audiencePlato's Dialogues continue to challenge our common definition of love. Whereas we commonly understand the primary meaning of love as an intense feeling addressed to an individual and attachment to his uniqueness-what we may call " personal love " hereafter-, Plato famously defines erôs as a force that drives each individual towards an object that appears to be rather abstract: Beauty (kalon). Platonic love provides the individual with happiness and leads him to virtue by knowledge of the Good. This intellectualized form of love goes together with a condemnation of sexual attachment and greediness, starting with the Symposium and the Phaedrus through to the Laws. It is therefore commonly argued that, for Plato, " personal love " cannot be an end in itself. As Vlastos has shown, love for an individual is a mere symptom of human deficiency, for the only thing truly worth loving is the Good, in a rather egoistic way. It is then a small step from the condemnation of inferior love whose paradigm is sexual attachment to an overall rejection of " personal love " , insofar as the lovers have not fulfilled the process of ascending the so-called " ladder of love " depicted in the Symposium (210a-212a)

Quaestiones practicae, medicae et chirurgicae

Copia digital. Valladolid : Junta de Castilla y León. Consejería de Cultura y Turismo, 2009-2010Sign.: a4, A-Z4, 2A-2G4, b-c4Port. con esc. calc. heráldic