Search for dissertations about: "equation"

Showing result 31 - 35 of 1504 swedish dissertations containing the word equation.

2. 31. Perturbed Renewal Equations with Non-Polynomial Perturbations

   Author : Ying Ni; Dmitrii Silvestrov; Anatoliy Malyarenko; Yuri Belyaev; Mälardalens högskola; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Renewal equation; perturbed renewal equation; non-polynomial perturbation; exponential asymptotic expansion; risk process; ruin probability; Mathematical statistics; Matematisk statistik; Mathematics Applied Mathematics; matematik tillämpad matematik;

   Abstract : This thesis deals with a model of nonlinearly perturbed continuous-time renewal equation with nonpolynomial perturbations. The characteristics, namely the defect and moments, of the distribution function generating the renewal equation are assumed to have expansions with respect to a non-polynomial asymptotic scale: $\{\varphi_{\nn} (\varepsilon) =\varepsilon^{\nn \cdot \w}, \nn \in \mathbf{N}_0^k\}$  as $\varepsilon \to 0$, where $\mathbf{N}_0$ is the set of non-negative integers, $\mathbf{N}_0^k \equiv \mathbf{N}_0 \times \cdots \times \mathbf{N}_0, 1\leq k . READ MORE

4. 32. Debugging techniques for equation-based languages

   Author : Peter Bunus; Linköpings universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Computer science; Datavetenskap;

   Abstract : Mathematical modeling and simulation of complex physical systems is emerging as a key technology in engineering. Modern approaches to physical system simulation allow users to specify simulation models with the help of equation-based languages. READ MORE

5. 33. Kinetic modelling of runaway in plasmas

   Author : Ola Embréus; Chalmers tekniska högskola; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Fokker-Planck equation; synchrotron radiation; plasma; runaway; bremsstrahlung; Boltzmann equation;

   Abstract : The phenomenon of runaway occurs in plasmas in the presence of a strong electric field, which overcomes the collisional friction acting on the charged particles moving through the plasma. A subpopulation of particles can then be accelerated to energies significantly higher than the thermal energy. READ MORE

6. 34. Stress, Flow and Particle Transport in Rock Fractures

   Author : Tomofumi Koyama; Lanru Jing; Marc Boulon; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Numerical simulation; laboratory experiments; rock fracture; coupled stress-flow-tracer test; shear displacement; fluid flow; particle transport; finite element method FEM ; particle tracking method; Navier-Stokes equation; Reynolds equation; streamline velocity dispersion.; Geoengineering; Geoteknik;

   Abstract : The fluid flow and tracer transport in a single rock fracture during shear processes has been an important issue in rock mechanics and is investigated in this thesis using Finite Element Method (FEM) and streamline particle tracking method, considering evolutions of aperture and transmissivity with shear displacement histories under different normal stresses, based on laboratory tests. The distributions of fracture aperture and its evolution during shear were calculated from the initial aperture fields, based on the laser-scanned surface roughness features of replicas of rock fracture specimens, and shear dilations measured during the coupled shear-flow-tracer tests in laboratory performed using a newly developed testing apparatus in Nagasaki University, Nagasaki, Japan. READ MORE

7. 35. Kinetic modelling of runaways in plasmas

   Author : Ola Embréus; Chalmers tekniska högskola; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; runaway; Fokker-Planck equation; tokamak; Boltzmann equation; positrons; bremsstrahlung; plasma; synchrotron radiation;

   Abstract : The phenomenon of runaway occurs in plasmas in the presence of a strong electric field, when the accelerating force overcomes the collisional friction acting on the charged particles moving through the plasma. Electron runaway is observed in both laboratory and space plasmas, and is of great importance in fusion-energy research, where the energetic electrons can damage the plasma-facing components of fusion reactors. READ MORE