The value of a position in a risky asset when optimally sold in an illiquid market is considered. The optimization problem is described as a stochastic impulse control problem, and it is shown that it is related to solving a system of quasi-variational inequalities. Existence of a solution to these inequalities are proved. A numerical implementation of the valuation algorithm is discussed and two

To improve image quality in a vertical field MR imaging unit, operating at low field strength (0.3 T), we have designed a half-elliptical coil for use in the upper thoracic region of small children. Our intention was also to shorten the examination time, which until now has been long, because several scans with different coils have been necessary to cover the thoracic region. The experimental coil

Sixty-two patients with newly diagnosed sarcoidosis were examined with fibreoptic bronchoscopy, endobronchial biopsies and bronchoalveolar lavage (BAL) were analysed. Epithelioid granulomatosis in endobronchial biopsies were found in 28 (45%) of the patients (BPOS). The patients in this BPOS group showed higher inflammatory activity in BAL fluid compared to those with negative biopsies (BNEG), wit

Splitting failure in beam splice joints with glued-in rods parallel to grain in endwood subjected to pure shear is considered. A simple theoretical expression based on beam-on-elastic-foundation theory and quasi-non-linear fracture mechanics is presented for calculation of the joint strength. Tests were conducted on jointed beams in a four-point bending test setup in which the joints were located

Background: The hazards of elective splenectomy in the elderly have not been thoroughly investigated. The aim was to assess such a well-defined cohort with respect to perioperative and long-term outcome. Methods: Fifty-two consecutively splenectomised patients during the period 1971-1995, aged 65 years or older, were followed until death (44 cases) or the end of 1999 (8 cases). Results: No intraop

The cat has served as an important nonrodent research model for neurophysiology and retinal degenerative disease processes, yet very little is known about feline neural precursor cells. To culture these cells and evaluate marker expression, brains were dissected from 45-day-old fetuses, enzymatically dissociated, and grown in the presence of EGF, bFGF and PDGF. Expanded cells widely expressed nest

Results from therapeutic trials with radiolabelled monoclonal antibodies are difficult to compare, because of lack of accurate macroscopic and microscopic dosimetry for both tumours and normal tissues. Requirements for such a dosimetry are covered in the paper. Accurate in vivo dosimetric measurement techniques for verification of calculated absorbed doses are also needed to verify treatment plann

Bird migration was recorded by tracking radar and visual observation at 23 sites in the region of the Northwest Passage, between Baffin Island and Herschel Island in the Beaufort Sea. The studies took place during a ship-based expedition from 29 June to 3 September 1999. A total of 692 tracks (average duration 160 s) of bird flocks on postbreeding migration were recorded. Eastward migration was wi

The present study concerns heat and mass transfer in porous media dried by superheated steam. Specifically, the steam drying process of a packed bed of porous particles was studied in order to obtain design data for a band drier. The small scale averaged governing equations describing the heat and mass transfer within the porous particles were derived. The inherent transport coefficients were eit

This thesis is a collection of six papers in computational algebra. In particular, we study noncommutative Gröb- ner bases, SAGBI bases and similar algebraic objects which can be represented as a graph or an automaton. In Paper I we introduce the concept of bi-automaton algebras, generalizing the automaton algebras previously defined by Ufnarovski. A bi-automaton algebra is a quotient of the free

Patterns in the interaction of cationic surfactants with nonionic polymer gels, which were inferred from a recent study from our laboratory, are confirmed by measurements of a series of alkylammonium surfactants with different counterions with a series of alkyl acrylamide gels of increasing hydrophobicity. Two swelling patterns were observed: Either the swelling continued above the surfactant crit

The long-acting beta 2-agonist salmeterol has been shown in several in vitro studies to produce non-beta-mediated relaxant effects. The aim of the present study was to investigate whether these effects have any relevance in humans in vivo. Thirteen healthy individuals were studied in a randomized, double-blind, cross-over study on five separate days. The subjects were pre-treated orally with eithe

Recent advances in magnetic resonance imaging have made it possible to visualize and quantify flow of cerebrospinal fluid (CSF) in the brain. The net flow of CSF through the cerebral aqueduct was used to measure CSF production in six normal volunteers at different times during a 24-h period. CSF production varied greatly both intra- and interindividually. The average CSF production in each time in

Popular Abstract in Swedish Moderna tillverkningsmaskiner är dyra och därför måste dess tillgänglighet och effektivitet ständigt hållas högt. Sådana resultat kan man inte åstadkomma utan tillämpning av en effektiv underhållsstrategi. Förutsättningar för att minska eller arrestera förslitnings hastighet på maskins delar och öka maskinlivslängden är stora vid användning av tillståndsövervakning, (TÖModern machinery is expensive and therefore must run at high availability and effectiveness which cannot be achieved without an effective maintenance policy. Condition monitoring, (CM), techniques can be utilised to reduce or arrest the rate of deterioration of a component so increasing operating life. The main result reported in this thesis is that the rolling element bearing’s mean effective li