Sökning: "Hyperbolic"

Visar resultat 36 - 40 av 115 avhandlingar innehållade ordet Hyperbolic.

1. 36. Combinatorics and zeros of multivariate polynomials

   Författare :Nima Amini; Petter Bränden; Jim Haglund; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Mathematics; Matematik;

   Sammanfattning : This thesis consists of five papers in algebraic and enumerative combinatorics. The objects at the heart of the thesis are combinatorial polynomials in one or more variables. We study their zeros, coefficients and special evaluations. Hyperbolic polynomials may be viewed as multivariate generalizations of real-rooted polynomials in one variable. LÄS MER

3. 37. Stable iterated function systems

   Författare :Erland Gadde; Hans Wallin; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Hausdorff metric; iterated function system IFS ; attractor; invariant set; address; Hutchinson’s metric; we a k* -topology; IFS with probabilities; invariant measure; the Random Iteration Algorithm;

   Sammanfattning : The purpose of this thesis is to generalize the growing theory of iterated function systems (IFSs). Earlier, hyperbolic IFSs with finitely many functions have been studied extensively. Also, hyperbolic IFSs with infinitely many functions have been studied. In this thesis, more general IFSs are studied. LÄS MER

4. 38. Perfectly Matched Layers and High Order Difference Methods for Wave Equations

   Författare :Kenneth Duru; Gunilla Kreiss; Jan Nordsröm; Ken Mattsson; Marcus Grote; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Elastic waves; Surface waves; Perfectly matched layers; High order difference methods; Stability; Summation-by-parts operators; Boundary treatments; Beräkningsvetenskap med inriktning mot numerisk analys; Scientific Computing with specialization in Numerical Analysis;

   Sammanfattning : The perfectly matched layer (PML) is a novel technique to simulate the absorption of waves in unbounded domains. The underlying equations are often a system of second order hyperbolic partial differential equations. In the numerical treatment, second order systems are often rewritten and solved as first order systems. LÄS MER

5. 39. Perfectly matched layers for second order wave equations

   Författare :Kenneth Duru; Gunilla Kreiss; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Beräkningsvetenskap med inriktning mot numerisk analys; Scientific Computing with specialization in Numerical Analysis;

   Sammanfattning : Numerical simulation of propagating waves in unbounded spatial domains is a challenge common to many branches of engineering and applied mathematics. Perfectly matched layers (PML) are a novel technique for simulating the absorption of waves in open domains. LÄS MER

7. 40. Topics in Analysis and Computation of Linear Wave Propagation

   Författare :Mohammad Motamed; Olof Runborg; Shi Jin; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Numerical analysis; Numerisk analys;

   Sammanfattning : This thesis concerns the analysis and numerical simulation of wave propagation problems described by systems of linear hyperbolic partial differential equations. A major challenge in wave propagation problems is numerical simulation of high frequency waves. LÄS MER