Zobrazeno 1 - 10
of 107
pro vyhledávání: '"Päivärinta, Lassi"'
We study the inverse scattering from a screen with using only one incoming time--harmonic plane wave but with measurements of the scattered wave done at all directions. Especially we focus on the 2D--case i.e. (inverse) scattering from an open bounde
Externí odkaz:
http://arxiv.org/abs/2409.02591
Publikováno v:
Bl{\aa}sten, E. L. K., P\"aiv\"arinta, L., Sadique, S. (2023). The Fourier, Hilbert, and Mellin transforms on a half-line. SIAM Journal on Mathematical Analysis, 55(6), 7529-7548
We are interested in the singular behaviour at the origin of solutions to the equation $\mathscr{H} \rho = e$ on a half-axis, where $\mathscr H$ is the one-sided Hilbert transform, $\rho$ an unknown solution and $e$ a known function. This is a simple
Externí odkaz:
http://arxiv.org/abs/2302.03521
Publikováno v:
Mathematics 2020, 8, 1156
We consider the problem of fixed frequency acoustic scattering from a sound-soft flat screen. More precisely the obstacle is restricted to a two-dimensional plane and interacting with a arbitrary incident wave, it scatters acoustic waves to three-dim
Externí odkaz:
http://arxiv.org/abs/2006.06546
Autor:
Ola, Petri1 (AUTHOR) petri.ola@helsinki.fi, Päivärinta, Lassi2 (AUTHOR) lassi.paivarinta@taltech.ee, Sadique, Sadia2 (AUTHOR)
Publikováno v:
Mathematics (2227-7390). Nov2023, Vol. 11 Issue 22, p4655. 12p.
We present a few ways of using conformal maps in the reconstruction of two-dimensional conductivities in electrical impedance tomography. First, by utilizing the Riemann mapping theorem, we can transform any simply connected domain of interest to the
Externí odkaz:
http://arxiv.org/abs/1702.07531
Autor:
Päivärinta, Lassi, Piiroinen, Petteri
In this paper, we study the recovery of the Hurst parameter from a given discrete sample of fractional Brownian motion with statistical inverse theory. In particular, we show that in the limit the posteriori distribution of the parameter given the sa
Externí odkaz:
http://arxiv.org/abs/1606.07576
Autor:
Cristina, Jan, Päivärinta, Lassi
We study the evolution equation $\partial_{t}u=-\Lambda_{t}u$ where $\Lambda_ {t}$ is the Dirichlet-Neumann operator of a decreasing family of Riemannian manifolds with boundary $\Sigma_{t}$. We derive a lower bound for the solution of such an equati
Externí odkaz:
http://arxiv.org/abs/1511.01233
We study an inverse acoustic scattering problem in half-space with a probabilistic impedance boundary value condition. The Robin coefficient (surface impedance) is assumed to be a Gaussian random function $\lambda = \lambda(x)$ with a pseudodifferent
Externí odkaz:
http://arxiv.org/abs/1407.2481
We prove the absence of non-scattering energies for potentials in the plane having a corner of angle smaller than $\pi$. This extends the earlier result of Bl{\aa}sten, P\"aiv\"arinta and Sylvester who considered rectangular corners. In three dimensi
Externí odkaz:
http://arxiv.org/abs/1404.2513
Autor:
Päivärinta, Lassi, Zubeldia, Miren
We study the inverse Robin problem for the Schr\"odinger equation in a half-space. The potential is assumed to be compactly supported. We first solve the direct problem for dimensions two and three. We then show that the Robin-to-Robin map uniquely d
Externí odkaz:
http://arxiv.org/abs/1311.6947