Sökning: "Graph Laplacian"

Visar resultat 1 - 5 av 7 uppsatser innehållade orden Graph Laplacian.

  1. 1. Phase Unwrapping MRI Flow Measurements

    Uppsats för yrkesexamina på avancerad nivå, Uppsala universitet/Avdelningen Vi3

    Författare :Mio Liljeblad; [2023]
    Nyckelord :phase unwrapping; computer vision; cine MRI; NMR; flow measurements; velocity encoding; venc; energy minimization; magnetic resonance; cardiac MRI; sinotubuar junction; pulmonary artery; ascending descending aorta; laplacian algorithm; iterative graph cuts; IGC; sequential tree-reweighted message passing; TRW-S; velocity to noise ratio; VNR; retrospective wrapping; energy formulation;

    Sammanfattning : Magnetic resonance images (MRI) are acquired by sampling the current of induced electromotiveforce (EMF). EMF is induced due to flux of the net magnetic field from coherent nuclear spins with intrinsic magnetic dipole moments. LÄS MER

  3. 2. Properties of Discrete Laplacians With Application on Brain Networks

    Master-uppsats, KTH/Matematisk statistik

    Författare :David Thinsz; [2022]
    Nyckelord :Graph Laplacian; Combinatorial Laplacian; Persistent Laplacian; Topological data analysis; Spectral theory; Homology; Clustering.; Graf-Laplacian; Kombinatorisk Laplacian; Beständig Laplacian; Topologisk dataanalys; Spektralteori; Homologi; Klustring.;

    Sammanfattning : This thesis investigates three discrete Laplace operators: the graph Laplacian, combinatorial Laplacian, and the more recently introduced persistent Laplacian. We discuss how these operators relate to each other and study their spectral properties. The graph Laplacian is a well-studied operator that plays a central role in spectral graph theory. LÄS MER

  4. 3. Image Processing using Graph Laplacian Operator

    Master-uppsats, KTH/Skolan för elektroteknik och datavetenskap (EECS)

    Författare :David Wobrock; [2019]
    Nyckelord :;

    Sammanfattning : The latest image processing methods are based on global data-dependent filters. These methods involve huge affinity matrices which cannot fit in memory and need to be approximated using spectral decomposition. LÄS MER

  5. 4. Low Supervision, Low Corpus size, Low Similarity! Challenges in cross-lingual alignment of word embeddings : An exploration of the limitations of cross-lingual word embedding alignment in truly low resource scenarios

    Master-uppsats, Uppsala universitet/Institutionen för lingvistik och filologi

    Författare :Andrew Dyer; [2019]
    Nyckelord :word embeddings; cross-lingual; multilingual; low-resource; corpus size; Vecmap; FastText; alignment; orthogonal; eigenvalues; Laplacian; isospectral; isomorphic; bilingual lexicon induction;

    Sammanfattning : Cross-lingual word embeddings are an increasingly important reseource in cross-lingual methods for NLP, particularly for their role in transfer learning and unsupervised machine translation, purportedly opening up the opportunity for NLP applications for low-resource languages.  However, most research in this area implicitly expects the availablility of vast monolingual corpora for training embeddings, a scenario which is not realistic for many of the world's languages. LÄS MER

  7. 5. A Game Theoretic Approach to Multi-Agent Cooperation with Application to Economic Systems

    Master-uppsats, KTH/Optimeringslära och systemteori

    Författare :Toshihiro Suzuki; [2014]
    Nyckelord :;

    Sammanfattning : Consensus problem with multi-agent systems has interested researchers in various areas. Its difficulties tend to appear when available information of each agent is limited for achieving consensus. LÄS MER