Essays about: "density gradients"

Showing result 11 - 15 of 26 essays containing the words density gradients.

1. 11. Spatial and temporal variability in grassland structure associated with different densities of the white rhinoceros (Ceratotherium simum) in a South African savanna

   University essay from SLU/Dept. of Wildlife, Fish and Environmental Studies

   Author : Emilia Malmström; [2019]
   Keywords : white rhinoceros; african savanna; keystone species; herbivory; cascading effects; poaching;

   Abstract : The direct and indirect relationships between species in different trophic levels are referred to as trophic dynamics and are important in maintaining the function of ecosystems. Megaherbivores may have effects both directly and indirectly on other species since their impact may be disproportionately large relative to their population size. READ MORE

3. 12. Measuring the Risk-neutral Probability Distribution of Equity Index Options

   University essay from Linköpings universitet/Produktionsekonomi

   Author : Gustav Dackner; Linus Falk; [2019]
   Keywords : ;

   Abstract : The focus of this master thesis is to develop a model that measures the risk-neutral probability distributionof the future value of a portfolio consisting of options on the S&P 500 index. The cornerstone of the model is an explicit and thorough construction of the local volatility surface. The parametric model of Coleman etal. READ MORE

4. 13. Innovative Methods for Welding Ultra High Strength Steel with Resistance Spot Welding

   University essay from KTH/Industriell produktion

   Author : Rickard Aldén; [2018]
   Keywords : ;

   Abstract : Resistance spot welding (RSW) is the most frequently used method for welding thin sheets in manufacturing industries such as the automotive industry, because of the high productivity of RSW. In order to reduce CO2 emissions the automotive industry strives towards creating structures of light weight, this is partly achieved by the use of lightweight materials such as Aluminum and composite materials. READ MORE

5. 14. Direct optimization of dose-volume histogram metrics in intensity modulated radiation therapy treatment planning

   University essay from KTH/Skolan för teknikvetenskap (SCI)

   Author : Tianfang Zhang; [2018]
   Keywords : Optimization; intensity-modulated radiation therapy; DVH functions; dose-at-volume; volume-at-dose; value-at-risk; smooth approximation; kernel density estimation; fluence map optimization; Optimering; intensitetsmodulerad strålterapi; DVH-funktioner; dose-at-volume; volumeat- dose; value-at-risk; slätapproximation; ickeparametrisk skattning; fluensoptimering;

   Abstract : In optimization of intensity-modulated radiation therapy treatment plans, dose-volumehistogram (DVH) functions are often used as objective functions to minimize the violationof dose-volume criteria. Neither DVH functions nor dose-volume criteria, however,are ideal for gradient-based optimization as the former are not continuously differentiableand the latter are discontinuous functions of dose, apart from both beingnonconvex. READ MORE

6. 15. Topology Optimization for Additive Manufacturing

   University essay from Lunds universitet/Hållfasthetslära

   Author : Kajsa Söderhjelm; [2017]
   Keywords : Topology optimization; Additive manufacturing; Overhang constraint; Technology and Engineering;

   Abstract : Topology optimization answers the question "How to place the material within a prescribed design domain in order to obtain the best structural performance? " and the design obtained is usually complex. Additive manufacturing comes with a well known design freedom and the design provided by topology optimization can be manufactured without as many constraints as conventional manufacturing methods. READ MORE