Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 203 for “"Laplacian"”.
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LAPLACIAN TYPE EQUATIONS
… in diversi spazi ambiente, con operatori p-Laplaciano e (p, q)-Laplaciano, dove p e q possono essere numeri reali o funzioni a valori reali. Si tratta di un importante campo di applicazione dei metodi variazionali, che sono utili strumenti non solo per studiare l'esistenza di soluzioni, ma …
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Geometric Computing beyond the Laplacian
The Laplace–Beltrami operator, or, Laplacian, is the central object of study in shape analysis, geometry processing, and scientific computing. Motivated by the ubiquity of Laplacian in geometric computing algorithms, this thesis initiates a program for systematically designing novel algorithms by …
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Variational Methods for p-Laplacian Sturm-Liouville Problems
… we address the problem of eigencurves for the p-Laplacian operator on [0,1]. First we examine the simple case where p=2. Next, we prove the existence and several properties of the first eigencurve and its corresponding eigenfunction. In chapters 4 and 5, the nonhomogeneous case is considered. …
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The Laplacian for spaces with cone-like singularities
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mathematics, 1990.
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Predictive image coding with Pseudo-Laplacian edge detector
… video signals. These algorithms use the Pseudo-Laplacian edge detector to switch between the textural coding and the edge coding. The one-dimensional Song DM coder and the two-dimensional weighted average prediction DM coder were used as the textural coding. The edge coding was done with either …
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Interpretable Deep Image Denoiser by Unrolling Graph Laplacian Regularizer
… optimization problem regularized using a graph Laplacian prior. To guarantee a minimum level of performance, we initialize the network to a known (pseudo-)linear denoiser, which is mapped to a corresponding graph Laplacian matrix specifying the MAP problem, leveraging a previous linear algebraic …
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Synthesis of Progressive Varying Texture Through Blending Laplacian Pyramid Coefficients
We generate a texture synthesis algorithm where there is gradual progression of merged textures in the output image. The goal of the algorithm is to merge the textures based on given measure of texture proportion. The proportion of texture contents defines how much of textures from each input will …
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Theory of the growth and shape of Laplacian stream networks
… in this part are equally applicable to any Laplacian network driven by locally symmetric Laplacian growth. Second, I consider the longitudinal profiles of a river network whose river slopes are sufficiently large to carry sediment downstream. This restriction on the profile of a river has …
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Efficient feature detection using OBAloG: optimized box approximation of Laplacian of Gaussian
… accurately and efficiently approximates the Laplacian of Gaussian using an optimal set of weighted box filters that take advantage of integral images to reduce computations. When combined with state-of-the art descriptors for matching, the algorithm performs better than leading feature …
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Learning Sparse Graph Laplacian with K Eigenvector Prior via Iterative GLASSO and Projection
… an eigen-structural assumption on the graph Laplacian matrix is considered: the first K eigenvectors of the graph Laplacian are pre-selected, e.g., based on domain-specific criteria, and the remaining eigenvectors are then learned from data. One example use case is image coding, where the …
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Learning strictly orthogonal p-order nonnegative Laplacian embedding via smoothed iterative reweighted method
Laplacian embedding is a powerful graph based method with its ability in spectral clustering to reveal the intrinsic geometry of data in the high dimensional space. Imposing the orthogonality and the nonnegativity constraints can avoid degenerate and negative solutions, respectively. These two …
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Upper bounds of second Laplacian eigenvalues on the sphere and the projective space
Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2026-05-01
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Fast generation of Gaussian and Laplacian image pyramids using an FPGA-based custom computing platform
… of image pyramids: the Gaussian pyramid and the Laplacian pyramid. These have been developed using the SPLASH II attached processor, which is a reconfigurable platform based on Field Programmable Gate Arrays (FPGA). The design was first modeled in VHDL, and was then simulated and synthesized to a …
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A geometric description of the heat kernel of the Witten Laplacian and the Cheeger-Müller theorem
Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2025-10-19 without embargo terms
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Spectral problems on triangles and disks: Extremizers and ground states
… we study how the energy levels of the Laplacian depend upon the shape of the domain, and identify the ground state energy level of the magnetic Laplacian on the disk. Although we consider these different questions we can find some kind of unity in the sense that we are looking at the …
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Fractional Chromatic Numbers and Spectra of Graphs
… spectra of edge-independent random graphs, Laplacian spectra of hypergraphs, and loose Laplacian spectra of random hypergraphs.</p> <p>For a graph $G$, let $\chi_f(G)$ be the fractional chromatic number of $G$. Based on the study of independence numbers of triangle-free graphs with maximum …
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The optimal mechanism in differential privacy
… the optimal performances with those of the usual Laplacian mechanism, we show that in the high privacy regime (epsilon is small), the Laplacian mechanism is asymptotically optimal as epsilon to 0; in the low privacy regime (epsilon is large), the minimum magnitude and second moment of noise are …
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Semiclassical spectral analysis of discrete Witten Laplacians
A discrete analogue of the Witten Laplacian on the n-dimensional integer lattice is considered. After rescaling of the operator and the lattice size we analyze the tunnel effect between different wells, providing sharp asymptotics of the low-lying spectrum. Our proof, inspired by work of B. …
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Fourth order spectral theory and diffusion-driven instability
… innovation is that we replace the traditional Laplacian diffusion operator with a combination of the fourth order bi-Laplacian operator and the second order Laplacian. We find new phenomena when the fourth order and second order terms are competing, meaning one of them stabilizes the system …
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Spectra of Periodic Schrödinger Operators on the Octagonal Lattice
… lattice using the Floquet-Bloch transform of the Laplacian. We will first consider the spectrum of the Laplacian in detail and prove various properties thereof, including spectral-band limits and locations of singularities. In addition, we will prove that Schrödinger operators with 1-1 periodic …
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