Sökning: "Spatial autocorrelation"

Visar resultat 21 - 25 av 26 avhandlingar innehållade orden Spatial autocorrelation.

1. 21. Fungal communities of West African ectomycorrhizal woodlands

   Författare :Brendan R. Furneaux; Martin Ryberg; Matthew Smith; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; ectomycorrhizal fungi; West Africa; metabarcoding; Sudanian woodlands; community ecology; ethnomycology; edible mushrooms; fungi; Biology with specialization in Systematics; Biologi med inriktning mot systematik;

   Sammanfattning : Ectomycorrhizal symbiosis is a widespread mutualist relationship between fungi and plants, often trees. It is most well-known in temperate and boreal forests, but also occurs in a variety of tropical ecosystems, including Sudanian savanna woodlands and gallery forests in West Africa. LÄS MER

3. 22. Generalized linear models with clustered data

   Författare :Henrik Holmberg; Erling Häggström Lundevaller; Göran Broström; Douglas Bates; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Statistics; statistik;

   Sammanfattning : In situations where a large data set is partitioned into many relatively small groups, and where the members within a group have some common unmeasured characteristics, the number of parameters requiring estimation tends to increase with sample size if a fixed effects model is applied. This fact causes the assumptions underlying asymptotic results to be violated. LÄS MER

4. 23. Spaceborne Synthetic Aperture Radar for Sea Ice Observations, Concentration and Dynamics

   Författare :Anders Berg; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; synthetic aperture radar; interferometry; satellite; sea ice dynamics; sea ice monitoring; sea ice concentration;

   Sammanfattning : Spaceborne Synthetic Aperture Radar (SAR) is the primary choice for sea ice monitoring due to its all-weather, day-and-night capability and regular delivery of high resolution images. This thesis presents methods for estimation of sea ice concentration and drift, a multi-sensor study of Baltic Sea ice radar signatures and an interferometric study of landfast sea ice. LÄS MER

5. 24. Short Pulses in Engineered Nonlinear Media

   Författare :Stefan Holmgren; Fredrik Laurell; Derryck Reid; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; nonlinear optics; KTiOPO4; frequency conversion; mode-locked lasers; ultra-fast lasers; visible lasers; short pulses; ultrafast nonlinear optics; diagnostic applications of nonlinear optics; nonlinear optical materials; Physics; Fysik;

   Sammanfattning : Short optical pulses and engineered nonlinear media is a powerful combination. Mode locked pulses exhibit high peak powers and short pulse duration and the engineered ferro-electric KTiOPO4 facilitates several different nonlinear processes. LÄS MER

7. 25. On perfusion estimation using ultrasound

   Författare :Tomas Jansson; Avdelningen för Biomedicinsk teknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Instrumentation technology; Speckle; Artifacts; Perfusion; Ultrasound; Doppler; Mät- och instrumenteringsteknik;

   Sammanfattning : This thesis has the main focus on ways to improve the blood perfusion estimate, as obtained from a continuous wave Doppler system. Earlier studies have shown large temporal variations in the detected perfusion estimate, due to speckle. LÄS MER