We present a new method for estimating the edges in a piecewise smooth function from blurred and noisy Fourier data. The proposed method is constructed by combining the so called concentration factor edge detection method, which uses a finite number of Fourier coefficients to approximate the jump function of a piecewise smooth function, with compressed sensing ideas. Due to the global nature of...

This paper is a contribution to the sensitivity analysis of piecewise smooth equations. A piecewise smooth function is a Lipschitzian homeomorphism near a given point if and only if it is coherently oriented and has an invertible B-derivative at this point. We emphasise the role of functions of the type f = g h where g is piecewise smooth and h is smooth and present veriiable conditions which e...

We consider region of interest (ROI) tomography of piecewise constant functions. We prove that continuous ROI data determine piecewise constant functions. Additionally, an algorithm is developed for ROI tomography of piecewise constant functions using a Haar wavelet basis. A weighted `p–penalty is used with weights that depend on the relative location of wavelets to the region of interest. We p...

Abstract. We present a Bayesian analysis for recurrent events data using a nonhomogeneous mixed Poisson point process with a dynamic subject-specific frailty function and a dynamic baseline intensity func- tion. The dynamic subject-specific frailty employs a dynamic piecewise constant function with a known pre-specified grid and the baseline in- tensity uses an unknown grid for the piecewise ...

For two high-quality piecewise polynomial geometrically smooth (G) surface constructions, explicit G functions are derived that form the basis of a functions space on the G surfaces. The spaces are refinable and nested, i.e. the functions can be rerepresented at a finer level. By choosing all basis functions to be first order smooth a maximal set of degrees of freedom is obtained that have smal...