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Visar resultat 1 - 5 av 972 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. Studies of vector tomography

    Författare :Kent Stråhlén; Matematik LTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Doppler tomography; Doppler Radon transform; local tomography; vectorial k-plane transform; vectorial Radon transform; k-plane transform; Radon transform; tomography; vector tomography; Mathematics; Matematik;

    Sammanfattning : The motivation to study the kind of problems appearing in this thesis has been ultrasound measurements of flows, from which velocity spectra along lines can be determined. These velocity spectra can mathematically be described by a new non-linear transform, here called the Doppler Spectral Transform (DST). LÄS MER

  3. 2. Towards Asymptotic Vector Quantization

    Författare :Jonas Samuelsson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; EM algorithm; parametric models; expectation maximization; spectrum coding; Gaussian mixture models; fast search; bounded support; multidimensional companding; vector quantization; high rate quantization;

    Sammanfattning : We study topics in source coding, and vector quantization (VQ) in particular. We approach VQ from two directions: a theoretical starting point based on high rate quantization theory, and a practical based on a database desription of the signal source. LÄS MER

  4. 3. Clearing up Culex Confusion : A Basis for Virus Vector Discrimination in Europe

    Författare :Jenny C. Hesson; Jan O. Lundström; Örjan Östman; Åke Lundkvist; Anssi Laurila; Laura D Kramer; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Culex torrentium; Culex pipiens; mosquitoes; vector; ornithophilic; Sindbis virus; West Nile virus; Populationsbiologi; Population Biology;

    Sammanfattning : Mosquito species of the Culex genus are the enzootic vectors for several bird-associated viruses that cause disease in humans. In Europe, these viruses include Sindbis (SINV), West Nile and Usutu viruses. The morphologically similar females of Cx. torrentium and Cx. LÄS MER

  5. 4. Replication-competent adenovirus 11p vector as a new oncolytic agent

    Författare :Jim Silver; Ya-Fang Mei; Gunnel Halldén; Umeå universitet; []
    Nyckelord :Virologi; Adenovirus; Vector; mikrobiologi; Microbiology;

    Sammanfattning : Human adenoviruses (Ads) as vectors have been studied for cancer gene therapy for several decades due to their ability to shut down host cell replication and lyse tumour cells. Ad5 of species C is commonly used as a replication-defective or a replication-competent vector. LÄS MER

  7. 5. Towards Low-Complexity Vector Quantization

    Författare :T. Z. Shabestary; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Gaussian encoder; source coding; companding; Gaussian mixture; random coding; vector quantization; spectral coding;

    Sammanfattning : This thesis is about constructing low-complexity, yet high-performance, vector quantizers (VQs) for 'real-world' sources. Knowledge concerning the source is extracted from a finite training set. In contrast with conventional VQ design procedures, we use the training set to estimate a statistical model for the source. LÄS MER