Search for dissertations about: "spherical harmonics"

Showing result 1 - 5 of 16 swedish dissertations containing the words spherical harmonics.

2. 1. Some problems concerning spherical harmonics

   Author : Einar Hille; Stockholms högskola; []
   Keywords : ;

   Abstract : .... READ MORE

4. 2. Global Shape Description of Digital Objects

   Author : Ola Weistrand; Christer Kiselman; Gunilla Borgefors; Örjan Smedby; Michael Floater; Uppsala universitet; []
   Keywords : Applied mathematics; shape description; shape approximation; surface parameterization; digital object; spherical harmonics; digital surface; digital image; Tillämpad matematik;

   Abstract : New methods for global shape description of three-dimensional digital objects are presented. The shape of an object is first represented by a digital surface where the faces are either triangles or quadrilaterals. READ MORE

5. 3. Simulating rolling noise on ballasted and slab tracks: vibration, radiation, and pass-by signals

   Author : Jannik Theyssen; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Railway rolling noise; Numerical modelling; Green s functions; Time domain; Spherical harmonics; Slab track; 2.5D FE BE;

   Abstract : Shifting to rail-bound freight and passenger traffic is key in Europe's strategy towards transport decarbonisation. However, increasing railway traffic can increase environmental noise pollution. Rolling noise is often the dominant noise source. It originates from the interaction of the rough running surfaces of wheel and rail. READ MORE

6. 4. Scattering of elastic waves by an anisotropic sphere with application to polycrystalline materials

   Author : Ata Jafarzadeh; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Spherical obstacle; Anisotropy; Attenuation; Polycrystalline materials; Effective wave number; T matrix; Phase velocity; Scattering;

   Abstract : Scattering of a plane wave by a single spherical obstacle is the archetype of many scattering problems in various branches of physics. Spherical objects can provide a good approximation for many real objects, and the analytic formulation for a single sphere can be used to investigate wave propagation in more complex structures like particulate composites or grainy materials, which may have applications in non-destructive testing, material characterization, medical ultrasound, etc. READ MORE

7. 5. Investigation of acoustic source characterisation and installation effects for small axial fans

   Author : Per-Olof Berglund; KTH; []
   Keywords : axial fan; airborne sound; source characterisation; transmission path analysis; in-duct. Spherical harmonics;

   Abstract : Fans are often used in equipment such as home appliances andelectronic equipment where the margin of profit is small butcustomers demands on a low noise level are high. Therefore,methods for predicting the noise emitted by an applicationincluding one or several fans are desirable in order toimprove, accelerate and reduce the cost of low-noise design. READ MORE