Sökning: "Uno Wennergren"
Visar resultat 11 - 15 av 15 avhandlingar innehållade orden Uno Wennergren.
11. Pairs of projections on a Hilbert space:properties and generalized invertibility
Sammanfattning : This thesis is concerned with the problem of characterizing sums, differences, and products of two projections on a separable Hilbert space. Other objective is characterizing the Moore-Penrose and the Drazin inverse for pairs of operators. We use reasoning similar to one presented in the famous P. LÄS MER
12. Permanence of age-structured populations in a spatio-temporal variable environment
Sammanfattning : It is widely recognized that various biotic and abiotic factors cause changes in the size of a population and its age distribution. Population structure, intra-specific competition, temporal variability and spatial heterogeneity are identified as the most important factors that, alone or in combination, influence population dynamics. LÄS MER
13. Quantifying Risk in Epidemiological and Ecological Contexts
Sammanfattning : The rates of globalization and growth of the human population puts ever increasing pressure on the agricultural sector to intensify and grow more complex, and with this intensification comes an increased risk of outbreaks of infectious livestock diseases. At the same time, and for the same reasons, the detrimental effect that humans have on other species with which we share the environment has never been more apparent, as the current rates of species loss from ecological communities rival those of ancient mass extinction events. LÄS MER
14. Conservation of semi-natural grasslands : Effects of different management methods on biodiversity
Sammanfattning : Species-rich semi-natural grassland are valuable habitats in the agricultural landscape as they may contain a high diversity of both plant and animal species, as well as provide essential ecosystem services like pollination. To keep these habitats open and to maintain the biodiversity in them, management like grazing or mowing is necessary. LÄS MER
15. Species’ responses to an ever-changing world
Sammanfattning : One of nature’s most astonishing features is the diversity of life, as more than a million species has been identified and classified. This diversity not only have a intrinsic value, but sustains us humans through a multitude of ecosystem services. Many of these services are critical for our sustenance. LÄS MER
