21 research outputs found

    Asymptotics for optimal design problems for the Schr\"odinger equation with a potential

    Get PDF
    We study the problem of optimal observability and prove time asymptotic observability estimates for the Schr\"odinger equation with a potential in L∞(Ω)L^{\infty}(\Omega), with Ω⊂Rd\Omega\subset \mathbb{R}^d, using spectral theory. An elegant way to model the problem using a time asymptotic observability constant is presented. For certain small potentials, we demonstrate the existence of a nonzero asymptotic observability constant under given conditions and describe its explicit properties and optimal values. Moreover, we give a precise description of numerical models to analyze the properties of important examples of potentials wells, including that of the modified harmonic oscillator

    Multiclass Data Segmentation using Diffuse Interface Methods on Graphs

    Full text link
    We present two graph-based algorithms for multiclass segmentation of high-dimensional data. The algorithms use a diffuse interface model based on the Ginzburg-Landau functional, related to total variation compressed sensing and image processing. A multiclass extension is introduced using the Gibbs simplex, with the functional's double-well potential modified to handle the multiclass case. The first algorithm minimizes the functional using a convex splitting numerical scheme. The second algorithm is a uses a graph adaptation of the classical numerical Merriman-Bence-Osher (MBO) scheme, which alternates between diffusion and thresholding. We demonstrate the performance of both algorithms experimentally on synthetic data, grayscale and color images, and several benchmark data sets such as MNIST, COIL and WebKB. We also make use of fast numerical solvers for finding the eigenvectors and eigenvalues of the graph Laplacian, and take advantage of the sparsity of the matrix. Experiments indicate that the results are competitive with or better than the current state-of-the-art multiclass segmentation algorithms.Comment: 14 page

    Asymptotics for Optimal Design Problems for the Schrodinger Equation with a Potential

    Get PDF
    We study the problem of optimal observability and prove time asymptotic observability estimates for the Schrodinger equation with a potential in L-infinity(Omega), with Omega subset of R-d, using spectral theory. An elegant way to model the problem using a time asymptotic observability constant is presented. For certain small potentials, we demonstrate the existence of a nonzero asymptotic observability constant under given conditions and describe its explicit properties and optimal values. Moreover, we give a precise description of numerical models to analyze the properties of important examples of potentials wells, including that of the modified harmonic oscillator
    corecore