This thesis deals with computational methods in algebra, mainly focusing on the concept of Gröbner and SAGBI bases in non-commutative algebras. The material has a natural division into two parts. The first part is a rather extensive treatment of the basic theory of Gröbner bases and SAGBI bases in the non-commutative polynomial ring. The second part is a collection of six papers. In the first pap

Scattering of electromagnetic waves from a red blood cell is simulated using the finite-difference time-domain method (FDTD), the Rytov approximation and the discrete dipole approximation (DDA). Both FDTD and DDA are full wave methods that give accurate results in a wide range of wavelengths. The Rytov approximation is a much simpler method that is limited to scattering angles within 30/spl deg/ f

Lifetimes for the3S1,3P0, 1, 2 and3D1, 2, 3 states in the 3s23p5p configuration of silicon have been determined using stepwise dye laser excitation and time resolved detection. A comparison is made with theoretical values, calculated using multi-configuration Hartree-Fock wavefunctions. Laser-evaporation was used to produce free silicon atoms by focusing a Nd: YAG laser on a rotating silicon targe

The performance of a turbo code is dependent on two code properties: its distance spectrum and its suitability to be iteratively decoded. Both these properties are influenced by the choice of interleaver used in the turbo encoder. This paper presents an interleaver design criterion that focuses on the performance of iterative decoding, based on the correlation properties of the extrinsic inputs. I

A contaminated site at Lernacken in southern Sweden, formerly used for sludge disposal, was investigated using a 3-D resistivity imaging technique. The data acquisition was carried out using a roll-along technique for 3-D data acquisition that allows using standard multielectrode equipment designed for engineering and environmental applications. The technique allows for the measurement of large tr

AIMS: The increase in risk for cardiovascular complications in diabetic women is even greater than that in diabetic men. We found arterial stiffness to be increased in women, but not in men, with Type 1 diabetes mellitus (DM). The aims of the present study were to evaluate whether the changes in arterial distensibility are influenced by diabetes duration and to evaluate any association between aut

The aim of this study was to compare interstitial laser thermotherapy with excision of a liver tumour. A dimethylhydrazine-induced adenocarcinoma was implanted into the left lateral lobe of the rat liver, and treatment was performed 8 days later. Rats were treated with resection of the tumour-bearing lobe or underwent interstitial laser thermotherapy, which was performed at a steady-state temperat

This paper argues that there is reason to be skeptical about the idea that the transition to a service economy will bring about dematerialization of production and consequent environmental improvement. This is because the shift to a service economy is an illusion in terms of real production, but is instead generated by the fall in the price of manufacturing goods relative to services, which is in

We consider a two-echelon distribution inventory system with a central warehouse and a number of retailers. The retailers face stochastic demand. The system is controlled by continuous review installation stock (R,Q) policies with given batch quantities. One way to decentralize the system control is to provide a backorder cost to the warehouse, and let the warehouse choose its reorder point so tha

In the generalization of the cranking model from rotation about a principal axis [one dimensional (1D)] to tilted rotation (2D and 3D), the mapping of the lowest total routhian on the yrast band is broken. In tilted rotation the single-particle energy diagrams cannot alone be used to construct the yrast band, because they lack information of the spin component perpendicular to the rotation axis. I

Taxonomy of dependent clauses i Swedish according to semantic, syntactic or lexical criteria.

In the present work a detailed kinetic soot model is applied to study the formation and oxidation of soot particles in laminar premixed and turbulent non-premixed flames. The soot model used in this study is based on a detailed description of the chemical and physical processes involved in the formation of soot. In the first part of the study the soot model is extended to include the formation of

Using a test TPC, consisting of the ALICE TPC field cage prototype in combination with the final ALICE TPC readout and electronics, the energy loss distribution and resolution were measured for identified protons. The measurements were compared to theoretical calculations and good quantitative agreement was found when detector effects were taken into account. The implications for particle identifi

The surface properties of a protein are often crucial for recognition and interaction with other molecules. Important functional residues can be identified by mutational analysis. There is a need for rapid methods to study protein surfaces and surface changes due to mutations. Partitioning in aqueous two-phase systems has the potential to be used in this respect since protein partitioning depends