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1 Superconvergent discontinuous Galerkin methods for second-order elliptic problems / A multiscale finite element method for partial differential equations posed in domains with rough boundaries / Alexandre L. Madureira 35 Convergence and optimality of adaptive mixed finite element methods / 79 Overlapping additive Schwarz preconditioners for elliptic PDEs(More)
—Radio frequency (RF) tomography is proposed to detect underground voids, such as tunnels or caches, over relatively wide areas of regard. The RF tomography approach requires a set of low-cost transmitters and receivers arbitrarily deployed on the surface of the ground or slightly buried. Using the principles of inverse scattering and diffraction(More)
We present an approach to performing rapid calculations of temperature within tissue by interleaving, at regular time intervals, 1) an analytical solution to the Pennes (or other desired) bioheat equation excluding the term for thermal conduction and 2) application of a spatial filter to approximate the effects of thermal conduction. Here, the basic(More)
We present a six-dimensional distributed vector sensor for Direction of Arrival estimation applications. A vector sensor should measure all 6 components of the electromagnetic field at the same location. Such sensor is motivated by recent analytical results, showing an improved estimation of the direction of arrival of the signal from a single source. Since(More)
Experimental data are used to validate a novel inversion scheme, based on a Conjugate Gradient algorithm. The proposed inversion provides actionable reconstruction results at a fraction of the computational effort needed by classical regularization techniques. Additionally, Conjugate Gradient allows us to introduce physical bounds on the solution returned,(More)
We describe the use of numerical Green's functions applied to Radio Frequency Tomography. RF Tomography relies on a linear operator in matrix form, which depends on a Green's function. The availability of the correct Green's function can be an important limitation when imaging in non-trivial scenarios. If the function cannot be found analytically, numerical(More)