Search results for "Theorem"
showing 10 items of 1250 documents
Total curvatures of convex hypersurfaces in hyperbolic space
1999
We give sharp upper estimates for the difference circumradius minus inradius and for the angle between the radial vector (respect to the center of an inball) and the normal to the boundary of a compact $h$-convex domain in the hyperpolic space. We apply these estimates to get the limit at the infinity for the quotients Volume/Area and (Total $k$-mean curvature)/Area of a family of $h$-convex domains which expand over the whole space. The theorem for the first quotient gives an extension to arbitrary dimension of a result of Santalo and Yanez for the hyperbolic plane.
THE HOROSPHERICAL GEOMETRY OF SUBMANIFOLDS IN HYPERBOLIC SPACE
2005
Some geometrical properties associated to the contact of submanifolds with hyperhorospheres in hyperbolic -space are studied as an application of the theory of Legendrian singularities.
Passive millimeter wave image classification with large scale Gaussian processes
2017
Passive Millimeter Wave Images (PMMWIs) are being increasingly used to identify and localize objects concealed under clothing. Taking into account the quality of these images and the unknown position, shape, and size of the hidden objects, large data sets are required to build successful classification/detection systems. Kernel methods, in particular Gaussian Processes (GPs), are sound, flexible, and popular techniques to address supervised learning problems. Unfortunately, their computational cost is known to be prohibitive for large scale applications. In this work, we present a novel approach to PMMWI classification based on the use of Gaussian Processes for large data sets. The proposed…
Geographical variation in pharmacological prescription
2009
Promoting rational drug administration in treatments is one of the most important issues in Public Health. Bayesian hierarchical models are a very useful tool for incorporating geographical information into the analysis of pharmacological prescription data. They allow the mapping of spatial components which express the trend of geographical variation. In addition, these models are able to deal with uncertainty in a sequential way through prior distributions on parameters and hyperparameters. Bayes' theorem combines all types of information and provides the posterior distribution which is computed through Markov Chain Monte Carlo (MCMC) simulation methods. Simulated data for pharmacological …
Hydrogen Supplied Wireless Charging System for Electric Vehicles
2020
The aim of this work is the experimental characterization of a Wireless Charging System based on IPT (Inductive Power Transfer) supplied by a PEMFC (Proton Exchange Membrane Fuel Cell) in order to verify the possibility of its installation in not electrified areas. A hydrogen-based supply system is designed and assembled with the purpose of having an EV (electrical vehicle) charging station not connected to the main power grid. An efficiency analysis of the wireless transmission system is carried out taking into account external parameters such as distance and misalignment between the transmitter coil and the receiver coil, verifying the integration potentialities of both IPT and fuel cell …
Contactless power transfer application for devices identification
2019
This paper deals with the problem of non-contact power transfer systems to identify components based on infrared signatures reading. This approach enables the distinction of a larger number of different devices situated in a relatively small area, compared to RFID technology. Moreover, the presented infrared contactless identification is resilient to natural environmental infrared perturbations. The advantages of this approach are demonstrated in a simple use-case: continuously identifying low consumption chess pieces on a custom chessboard. This approach can be further instantiated for high consumption devices such as electrically charging small autonomous guided vehicles.
Altered metabolism of gut microbiota contributes to chronic immune activation in HIV-infected individuals.
2015
Altered interplay between gut mucosa and microbiota during treated HIV infection may possibly contribute to increased bacterial translocation and chronic immune activation, both of which are predictors of morbidity and mortality. Although a dysbiotic gut microbiota has recently been reported in HIV + individuals, the metagenome gene pool associated with HIV infection remains unknown. The aim of this study is to characterize the functional gene content of gut microbiota in HIV + patients and to define the metabolic pathways of this bacterial community, which is potentially associated with immune dysfunction. We determined systemic markers of innate and adaptive immunity in a cohort of HIV-in…
Continuous spectrum for a two phase eigenvalue problem with an indefinite and unbounded potential
2020
Abstract We consider a two phase eigenvalue problem driven by the ( p , q ) -Laplacian plus an indefinite and unbounded potential, and Robin boundary condition. Using a modification of the Nehari manifold method, we show that there exists a nontrivial open interval I ⊆ R such that every λ ∈ I is an eigenvalue with positive eigenfunctions. When we impose additional regularity conditions on the potential function and the boundary coefficient, we show that we have smooth eigenfunctions.
A pseudo-Jahn–Teller model of the photochromic effect in sodium nitroprusside
2003
Abstract A new model for the photochromic effect in sodium nitroprusside Na2[Fe(CN)5(NO)]·2H2O based on the concept of the pseudo-Jahn–Teller effect is proposed. The model takes into account the electron transfer from the Fe2+ ion to the π* orbitals of the NO-ligand as well as the vibronic mixing of three electronic states of the Fe NO fragment through the non-symmetric and full-symmetric modes. The problem is solved within the adiabatic approximation. Under certain conditions the lower sheet of the adiabatic potential is shown to possess three minima with the increasing energies that correspond to the N-bound, sideways bound and O-bound NO group. The barriers between the minima are estimat…
Robust stability and stabilization of uncertain T-S fuzzy systems with time-varying delay: An input-output approach
2013
An input-output approach to the stability and stabilization of uncertain Takagi-Sugeno (T-S) fuzzy systems with time-varying delay is proposed in this paper. The time-varying parameter uncertainties are assumed to be norm-bounded, and the delay is intervally time varying. A novel method is employed to approximate the time-varying delay, based on which the considered system is transformed into a feedback interconnection form. The new formulation of the system is comprised of a forward subsystem with constant time delay and a feedback subsystem embedding the uncertainties. By applying the scaled small-gain theorem to the converted system, less conservative stability and stabilization criteria…