A statistical approach to a posteriori blockmodeling for digraphs and valued digraphs is proposed. The probability model assumes that the vertices of the digraph are partitioned into several unobserved (latent) classes and that the probability distribution of the relation between two vertices depends only on the classes to which they belong. A Bayesian estimator based on Gibbs sampling is proposed

Signal processing can be used to condition medical signals to facilitate their interpretation, and to extract clinically important information. The purpose of the present doctoral thesis is to put forward solutions to certain problems encountered in the processing of electrocardiac signals. Paper I examines the properties of a maximum likelihood method for aligning vectorcardiographic loops, with

Time-domain fundamental solutions and Green dyadics for temporally dispersive, simple media are introduced. Second forerunner approximations to the electromagnetic fields from an electric point dipole in unbounded dispersive materials are obtained. Numerical results for two frequently used material models are presented. Moreover, surface integral representations of the electromagnetic fields in di

Dwarf eggs, e.g. eggs that are very much smaller than normal eggs, are occasionally found among normal eggs in nests of birds. Although they are not often mentioned in the handbooks, the frequency of dwarf eggs seems to be about one per thousand, or less. In 2001 I found one dwarf egg in a nest with two eggs of the Long-tailed Skua Stercorarius longicaudus at Ammarnas in Swedish Lapland. I did not

A stability criterion for nonlinear systems, recently derived by thethird author, can be viewed as a dual to Lyapunov's second theorem.The criterion is stated in terms of a function which can beinterpreted as the stationary density of a substance that is generatedall over the state space and flows along the system trajectoriestowards the equilibrium.The new criterion has a remarkable convexity pro

The population of metastable states produced in relativistic-energy fragmentation of a U-238 beam has been measured. For states with angular momentum greater than or similar to 20h, a much higher population than expected has been observed. By introducing a collective component to the generation of angular momentum the experimental data can be understood. This is the first time that a collective de

Popular Abstract in Swedish När yrkesutbildningar teoretiseras ställs lärare och studerande inför skriftspråksbaserad, ofta abstrakt information som de förväntas läsa, kritiskt granska, ifrågasätta och omskapa till något eget. Språk och lärande hör nära samman, men när de studerandes vardagsspråk ska möta sådana texter kan språkandet skapa problem. Vårt sociala sammanhang har stor betydelse för vaBrandvägg describes how a group of firefighters, who consistently maintain that they are “practitioners and not theorists”, relate to various forms of language based knowledge and language based “knowledging” in their vocational training, which is based on problem based learning. From a sociocultural perspective to learning, and within the parameters of a didactic perspective with the focus on the

It is fairly uncontroversial that there is a large gap between the communicative and cognitive systems of non-human animals and those of human beings. There is much less consensus, however, on what the nature of this gap is, and even less on how it was bridged in evolution.

Hot luminescence of self-trapped excitons in solid xenon has been investigated in a wide temperature range (from LHeT to 100 K), using X-ray and two-photon excimer laser (ArF and KrF) excitation. Hot luminescence of bulk Xe crystals of volume 2 cm(3) appears to be very sensitive to both the temperature and the quality of the samples, while its highest intensity has been registered under KrF laser