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1038 Uppsatser om Signal species - Sida 8 av 70
En jämförelse mellan får- och nötkreatursbetade hagmarker med avseende på populationsstorlek samt artsammansättning hos dagfjärilar och örter
Many of Europe?s day-living butterflies have shown decreasing populations during the last decades and many species are threatened. Many butterflies are dependent on managed semi-natural grasslands because of their richness in nectar sources and host plants for the butterfly larva. Swedish pastures are mostly managed through grazing. The number of cattle in Sweden have been decreasing while the number of sheep in the country increased by 30%.
Kan en periodiseringsbaserad investeringsstrategi effektiviseras med hjälp av fundamental analys?
This paper investigates whether the traditional accrual based trading strategy first documented by Sloan (1996) can be refined using fundamental analysis. Specifically, this is done by implementing the composite signal F_SCORE introduced by Piotroski (2000) to identify financially strong or weak firms. We find that by applying both investment models simultaneously, in a model we call P_KOMB, the mean market-adjusted return earned by an investor exploiting the accrual anomaly can be increased by 14.8% annually. This is achieved by taking a long position in strong firms (as defined by the composite signal) in the lowest accrual portfolio, while an offsetting short position is taken in weak firms in the highest accrual portfolio, repeated annually between 1997 and 2007. Consistent with prior studies, positive market-adjusted returns can be attained through assessment of accruals as well as key value drivers found in historical financial data.
Utveckling av projektlaborationför signalbehandling : med digital signalprocessor programmeradmed LabVIEW och Matlab
This report describes how to process audio signals in real time with a digital signalprocessor. The digital signal processor used in the thesis and described in the reportare the Blackfin processor ADSP-BF537 from Analog Devices.In the body of this report there is theory of the processor characteristics and thevarious programming languages used. All experiments that were made on theprocessor are described, these descriptions also help in understanding the annexeswhere the experiments will be presented. The body of this report also describes theprogram used to do experiments. Testing the CPU limit was done and the results arepresented to get a good view of what it can handle.
Survey of Fusarium species on yellow onion (Allium cepa) on Öland
It has been observed by both onion producers and a plant protection advisor on Öland (an island off the east coast of Sweden) that basal rot is the largest contributory factor to reduced onion quality and yield. Basal rot is mainly caused by species of Fusarium fungi. The aim of this study was to: a) investigate which species of Fusarium that can be found in onion produced on Öland, b) describe the symptoms caused by the different Fusarium fungi found and c) explore, through interviews with the onion producers on Öland, the mechanisms that may be involved in the observed increase in basal rot.Onion bulbs (Allium cepa) were sampled on two occasions. In total 181 onions from 11 different fields were analysed. In addition, eight onion producers were interviewed.
Grodsamhällen längs vattendrag på Borneo : En identifiering av habitatkaraktärer viktiga för diversitet och abundans av grodor i tropisk regnskog
The stretch from the riparian zone of a major river, through the mouth and upstream in tributaries forms a range of differing habitats. The aim of this study was to investigate the effect of these different habitats on the riparian frog community in primary rain forest in Borneo; i.e. examine whether any gradients could be demonstrated in terms of species composition, diversity and density of frogs, as well as which environmental characteristics that seem to be of most importance in forming habitats of high conservational value. A major river, Segama, and three of its tributaries were investigated. The surveys were carried out at night by searching for frogs visually and acoustically along the streams, from the shore of the Segama river and 400 metres upstream in the tributaries.
Variation in protein precipitation and phenolic content within and among species across an elevational gradient in subarctic Sweden
This project investigated how elevation and vegetation type influences variation in plant litter phenolic content and protein precipitation capacity among and within common plant species for two different vegetation types, heath and meadow, in a subarctic ecosystem in the Abisko region of northern Sweden. As nutrient availability generally decreases with increasing elevation as a result of decreasing temperature, I hypothesised that phenolic content would increase with elevation and be higher on the heath than the meadow. To test this, the total phenolic content and protein precipitation capacity was estimated in leaf litter from 13 species in both heath and meadow vegetation across an elevational gradient ranging from 500 to 1000 meters above sea level (m.a.s.l.) in the study region. The results showed that elevation and vegetation type both had a strong impact on both variables. Total phenolic concentrations decreased with elevation for the meadow, and were greater for the heath than the meadow.
Kunskapsläge och attityder till vildsvin (Sus scrofa) och dess förvaltning i Sverige
The wild boar (Sus scrofa) is since its recent establishment and increasing density a controversial species in Sweden. But the attitudes towards the wild boar are poorly documented so far. To improve this knowledge, a questionnaire was sent out to chosen people (n=400) connected to the management and/or land use activities.
The study got 162 replies (reply frequency 40,5%) and the results show varying attitude trends among organizations and individuals, with some aspects coherent within groups and some not. Farmers and their organization showed the most negative attitudes towards wild boars, which was expected due to the practical and economic problems they suffer from this species. People involved with forestry were more positive to wild boars, probably because the species does not affect forest growth etc severely, and may even promote plant establishment by the rooting.
Nya träd för stadsmiljö
Trees in urban environment are exposed to extreme conditions, foremost the ones that grow in the hard packed soil along our streets. They are also exposed to damaging insects and fungal diseases both local and new ones spreading from South Europe. The global warming with warmer temperatures provides a longer growing season, making it easier for insects and fungus to establish a habitat. Based on these facts new tree species need to be available for future urban plantings.To determine what these trees would be an interview study began. Six people were selected who have experience in the field of urban environment planting.
Design av slutsteg med digital PWM-teknik för gitarr
Softube has developed DSP-card and software for simulation of the sound of old tube amplifiers. The purpose with this thesis is to design a compact amplifier with high power to function together with the DSP-card and build a unit that can replace several other guitar amplifiers. The advantages with that kind of solution could be that it would be cheaper, easier to carry and easier to stor than the real amplifiers. The amplifier that has been designed is of class D type with digital PWM modulator. There is several types of amplifier modules on the market that use analog input signal, but if one of them would be used a D-A converter is needed on the DSP card.
Biologin hos svenska Lilioceris arter och åtgärder för att begränsa deras skadeverkningar :
Summary
The leaf beetles, Lilioceris lilii and L. merdigera have existed in Asia, Europe and in North Africa for a long time, but have become much more abundant the last twenty-five years. Even North America has been affected during the last years.
The purpose of this investigation of Lilioceris species in Sweden, is to give advice to gardeners, which type of control measures is the most effective in order to restrict their damage to lilies.
Lilioceris species overwinter normally as pupae in the soil under the host or close by.
Literature and contact with advisors have described the life cycle and spreading of Lilioceris. Under favourable conditions these leaf beetles have two generations/year in the south of Sweden. Both the adults and the larva eat the foliage, and by strong attacks even flowers can be eaten and only the stem is remaining.
My own observations include different treatments of both lily foliage and of the leaf beetle.
Prestanda och precision pa? en enkortsdator i ett system med realtidskrav
The report aims to investigate how well a certain type of affordable embedded single board computer can hold up against today's more expensive computers in a computer system by doing various tests on a system with the specified requirements. The system has a Raspberry Pi as the single board computer which task is to control a camera based on coordinates obtained from a server as well as capture and stream a video signal on a network.The researches were conducted to check how much network traffic a single-chip computer sent in different video formats and how much CPU utilization was required. Studies were also made to ensure the accuracy of the camera control. The researches have been experimental, where several tests have been performed and analyzed.The results show that a sufficiently good accuracy can be obtained from the camera steering unit, in which two different servos have been investigated. When the video format MJPEG and H.264 are used, the single-chip computer is able to transmit a video signal up to 1280x720 at 15 fps.
Sammanvägning av diversitetssignaler med FPGA
Genom samtal med radioamatörer visade det sig att det fanns ett intresse för att använda rumsdiversitet på deras mottagare då de upplevde fädning (vid körning med bil) som ett problem för hörbarheten. I ett system där mottagaren är stationär och sändaren mobil kommer den mottagna signalen att fäda ibland då radiovågorna tar olika vägar till mottagaren och ibland förstärker och ibland stör varandra. Tanken med detta examensarbete var att kunna ta emot två bandbegränsade audiosignaler från två mottagare med varsin antenn som tar emot samma signal (rumsdiversitet) och vikta ihop dessa med lämplig metod för att få ut en bättre signal. Om man kunde implementera ett diversitetssystem med VHDL i en FPGA så skulle man få ett system som var både billigt och flexibelt. I det här examensarbetet har jag försökt att konstruera ett sådant system..
GIS-modellering av habitat för vitryggig hackspett (Dendrocopos leucotos) som hjälpmedel i naturvårdsplanering på landskapsnivå :
The white-backed woodpecker is a forest bird being critically endangered in Sweden. The species is dependent on older forests rich in deciduous trees and dead wood. The main problem for the survival of this species is present shortage of habitat. Conservation work on this umbrella species is at present focused on finding remaining or emerging habitat networks. Large areas are scrutinized in search for suitable habitats to be protected or managed for the species sake.
Lugnare katter på kliniken? : en studie om användningen av syntetiska analoger tillfelina ansiktsferomoner på svenska djursjukhus
Pheromones are chemical substances representing very specific signal messages within a species. Although a lot remains unknown about their precise effects, it is known that pheromones influence the behaviour of the receiver. Since the mid 1990s, when it was first possible to synthesise analogues of two fractions of feline facial pheromone, F3 (Feliway®) and F4 (Felifriend®), these have been used in so called pheromonotherapy to treat behavioural problems in cats. The initial use of pheromones for specific behavioural problems has been extended to cover the wide field of stress related issues. This studycontains a questionnaire where veterinary nurses and surgeons at 50 Swedish veterinary hospitals and clinics were asked about their use of synthetic analogues to feline facial pheromones in the care and treatment of cats.
Vems landskap ska förändras för att öka den biologiska mångfalden? : En studie av skillnaderna i odlingslandskapets konnektivitet med avseende på två skyddsvärda arter med olika preferenser
Organisms relevant for nature conservation dont follow administrative borders. Because of this there is a need for a landscape perspective within conservation and planning, and a need for the species of interest to have legal protection. Network analysis adapted for ecological purposes has grown to become a powerful tool for studying and communicating the relationships between species dispersion and access to habitat. In this study the following question is posed: How is the Osmoderma eremita and the Pernis apivorus dispersal possibilities in the small scale cultivated landscape of Borås affected by exploitation in respect to a) dispersal ability, b) habitat quality, c) position of habitat patches in a network? The analysis were based on municipal and regional nature conservation data, which in due to confidentiality is not accounted for in the report by maps, coordinates, etc.