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Visar resultat 1 - 5 av 92 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. Estimation of wood fibre length distributions from censored mixture data

    Författare :Ingrid Svensson; Sara Sjöstedt - de Luna; Lennart Bondesson; Aila Särkkä; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; censoring; fibre length distribution; identifiability; increment core; length bias; mixture; stochastic EM algorithm; Mathematical statistics; Matematisk statistik;

    Sammanfattning : The motivating forestry background for this thesis is the need for fast, non-destructive, and cost-efficient methods to estimate fibre length distributions in standing trees in order to evaluate the effect of silvicultural methods and breeding programs on fibre length. The usage of increment cores is a commonly used non-destructive sampling method in forestry. LÄS MER

  3. 2. Near wall fibre orientation in flowing suspensions

    Författare :Allan Carlsson; Daniel Söderberg; Fredrik Lundell; Helge I. Andersson; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; fluid mechanics; fibre orientation; shear flow; wall effect; fibre suspension; papermaking; Fluid mechanics; Strömningsmekanik;

    Sammanfattning : This thesis deals with fibre orientation in wall-bounded shear flows. The primary application in mind is papermaking. The study is mainly experimental,but is complemented with theoretical considerations.The main part of the thesis concerns the orientation of slowly settlingfibres in a wall-bounded viscous shear flow. LÄS MER

  4. 3. Estimation of Wood Fibre Length Distributions with Data from Increment Cores

    Författare :Ingrid Svensson; Lennart Bondesson; Sara Sjöstedt deLuna; Aila Särkkä; Umeå universitet; []
    Nyckelord :Censoring; EM algorithm; fibre length distribution; increment core; MCEM algorithm; mixture distribution;

    Sammanfattning : .... LÄS MER

  5. 4. Fibre-Optic Displacement and Temperature Sensing Using Coupling Based Intensity Modulation and Polarisation Modulation Techniques

    Författare :Johan Jason; Hans-Erik Nilsson; Bertil Arvidsson; Werner Daum; Mittuniversitetet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; optical fibre sensor; displacement measurement; temperature measurement; fibre coupling; intensity modulation; birefringence; polarisation; OTDR; side-hole fibre;

    Sammanfattning : Optical fibre sensors are employed in the measurements of a number of different physical properties or for event detection in safety and security systems. In those environments which suffer from electromagnetic disturbance, in harsh environments where electronics cannot survive and in applications in favour of distributed detection, fibre-optic sensors have found natural areas of use. LÄS MER

  7. 5. Fibre Orientation Modelling Applied to Contracting Flows Related to Papermaking

    Författare :Marko Hyensjö; Anders Dahlkild; Markku Kataja; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Fokker-Planck; fibre orientation; shear flow; fibre suspension; planar contraction; headbox; turbulent flow; Other engineering mechanics; Övrig teknisk mekanik;

    Sammanfattning : The main goal of this work was to develop numerical models for studying the behaviour of fibres in an accelerated flow. This is of special interest for e.g. papermaking. LÄS MER