This report deals with identification of multivariable linear systems of finite order from measurements of input-output signals when the outputs are corrupted by additive random noises. The input-output relations of such systems can be described by a vector difference equation. A canonical form for the matrix coefficients of this equation is proposed and its existence and uniqueness are shown. Thi

in this paper, the problem of diffraction of a spherical wave by a hard half-plane is considered. The starting point is the Biot-Tolstoy theory of diffraction of a spherical wave by a fluid wedge with hard boundaries. In this theory, the field at a point in the fluid is composed eventually of a geometrical part: i.e., a direct component, one or two components due to the reflections on the sides of

Abstract in German Zur Bestimmung der Prävalenz vonHepatitis A Virus-Antikörpern (anti-HAV) bei Drogenabhängigen wurden Seren von 234 Drogenabhängigen mit akuter Hepatitis B, die in einer schwedischen Stadt während zehn Jahren gesammelt worden waren, auf anti-HAV getestet. Zum Vergleich wurde eine normale Bevölkerungsgruppe herangezogen, bei der nur 3,8% der nach 1950 Geborenen und 8,2% der JahrgäTo determine the prevalence of antibodies to Hepatitis A virus (anti-HAV) among drug addicts, sera collected in a Swedish city during a ten-year period from 234 drug addicts with acute hepatitis B were tested for anti-HAV. The results were compared with the normal population, where only 3.8% of those born after 1950 were anti-HAV-positive. In individuals born between 1941 and 1965, 8.2% in the nor

Adsorption of 0.2 ML Na on Al(1 0 0) at room temperature yields a disordered Al(1 0 0)-(1 x 1)-Na phase, which transforms reversibly to a well-ordered Al(1 0 0)-(root5 x root5)R27degrees-Na phase on cooling below 250 K. Based on low energy electron diffraction (LEED) and high resolution core-level spectroscopy (HRCLS) measurements, and on ab initio calculations, it is concluded that the structure

Host-plant volatiles or other volatiles that attract moths, especially females, could be useful as trap baits or as a complement to pheromones in pest management. Three chocolate products, which had previously been found to be attractive to other pyralid moths, were screened by combined gas chromatography-electrophysiology for compounds that could be used for trapping of Ephestia kuehniella Zeller

This paper presents a study of the turbulence field in an optical diesel engine operated under motored conditions using both large eddy simulation (LES) and Particle Image Velocimetry (PIV). The study was performed in a laboratory optical diesel engine based on a recent production engine from VOLVO Car. PIV is used to study the flow field in the cylinder, particularly inside the piston bowl that i

Popular Abstract in Swedish Avhandlingen innehåller en ny metod att behandla ekvationer av den typ som styr t.ex. värmeledning och diffusion. Användning av ''halva derivator'' i tidsled möjliggör ett angreppssätt mycket likt den välkända Dirichlets princip inom elektrostatiken. Fördelen jämfört med existerande metoder är att den nya metoden ger en enkel och strömlinjeformad behandling av källtermeIn this work we study a variational method for treating parabolic equations that yields new results for non-linear equations with low regularity on source and boundary data. We treat mainly strongly parabolic quasilinear equations and systems in divergence form. The basic idea is to compose the parabolic operator with a weighted sum of the identity operator and the Hilbert transformation in the ti

Popular Abstract in Swedish Denna avhandling baseras på studier av de provtagningscykloner vilka används vid yrkeshygienisk provtagning av respirabelt damm i Sverige och andra andra länder i Europa. Målsättningen för arbetet har varit att avgöra huruvida cyklonernas mätvärden är valida relativt internationella provtagningskonventioner för respirabelt damm, samt eventuellt förbättra deras överensstThe performance of cyclones used in occupational hygiene for sampling respirable dust was studied. Test methods for experimental determination of cyclone penetration have been designed and validated. The penetration curve for a sampling cyclone presently used in Europe was measured. The sampler's performance relative to three sampling conventions for respirable dust was determined. The cyclone was

RATIONALE AND OBJECTIVES: To improve the measurement of the glomerular filtration rate (GFR), we determined the extrarenal plasma clearance of the GFR markers iohexol, chromium-51-ethylenediaminetetraacetic acid (51Cr-EDTA), and inulin using 11 anephric pigs. METHODS: After an intravenous (i.v.) bolus injection of the markers, the decay curves of their plasma concentrations were monitored for 29 h

To evaluate the effects of dietary phospholipids on plasma lipoproteins in the postprandial phase six normolipidemic men were fed alternatively a test meal rich in phosphatidylcholine and a control meal low in phosphatidylcholine. Plasma very low-density lipoproteins, low-density lipoproteins, and high-density lipoproteins were isolated at 2, 4 and 6 h after the meals. The changes in lipoprotein c

TSH secretion from the anterior pituitary is mainly regulated by TRH and thyroid hormones. We hypothesized that in addition the pituitary itself could modulate TSH production by sensing its own TSH release, enabling fine-tuning of TSH secretion. For such an ultra-short loop control, the pituitary should contain a TSH receptor (TSH-R). To find evidence for this we screened a human pituitary complem

For the precise determination of the local mass density in thin samples analysed at the Lund Nuclear Microprobe, a modified version of off-axis STIM is described. An on-axis/off-axis geometry is used where a thin C-foil, placed behind the sample scatters protons into the particle detector. The advantage of this geometry compared to the off-axis case where particles are directly scattered from the

Popular Abstract in Swedish Politiskt deltagande är ett komplext studieobjekt. I denna studie har det politiska deltagandet studerats utifrån att det i grunden handlar om aktiviteter som syftar till att påverka offentliga beslut. Följande frågeställningar ligger till grund för studien: (1) Hur förhåller sig olika former av politiskt deltagande till idén om politisk jämlikhet? (2) Hur kan vi teorePolitical participation is promoted as a central component in a democracy. But what specifically is it that makes participation valuable and how do different forms of participation differ in regard to outcomes? A central aim of this study is to understand why different forms of participation produce different kinds of effects. The argument developed is that participation can be understood as havin

Using near-infrared femtosecond absorption spectroscopy, we have determined the S-1 energies of the carotenoids spheroidene and rhodopin glucoside in LH2 complexes of purple bacteria. The S-1 energies in the LH2 complexes yield values of 13400 +/- 100 cm(-1) for spheroidene and 12550 +/- 150 cm(-1) for rhodopin glucoside, which are very close to the S-1 energies obtained for both carotenoids in so

The first EGF-like module of human coagulation factor IX contains a single functionally important calcium ion binding site. We have now shown the dissociation constant for this site to be approximately 160 microM in a recombinant protein fragment consisting of residues 1-85 in human fIX. This represents a approximately 10-fold increase in affinity as compared with the isolated EGF module (residues

We present a flexible and compact, digital, lock-in detection system and its use in high-resolution tunable diode laser spectroscopy. The system involves coherent sampling, and is based on the synchronization of two data acquisition cards running on a single standard computer. A software-controlled arbitrary waveform generator is used for laser modulation, and a four-channel analog/digital board r