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Visar resultat 1 - 5 av 12 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Stochastic model updating and model selection with application to structural dynamics

   Författare :Majid Khorsand Vakilzadeh; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Finite element model; Bayesian model selection; Bayesian model updating; stochastic simulation; Bootstrapping; Subspace system identification; Uncertainty quantification;

   Sammanfattning : Uncertainty induced by our incomplete state of knowledge about engineering systems and their surrounding environment give rise to challenging problems in the process of building predictive models for the system behavior. One such challenge is the model selection problem, which arises due to the existence of invariably multiple candidate models with different mathematical forms to represent the system behavior, and so there is a need to assess their plausibility based on experimental data. LÄS MER

3. 2. Essays on forecasting and Bayesian model averaging

   Författare :Jana Eklund; Handelshögskolan i Stockholm; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : This thesis, which consists of four chapters, focuses on forecasting in a data-rich environment and related computational issues. Chapter 1, “An embarrassment of riches: Forecasting using large panels” explores the idea of combining forecasts from various indicator models by using Bayesian model averaging (BMA) and compares the predictive performance of BMA with predictive performance of factor models. LÄS MER

4. 3. Environmental risk assessment of shipwrecks – Model development and application

   Författare :Hanna Landquist; Chalmers tekniska högskola; []
   Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Bayesian updating; shipwreck; environmental risk assessment; fault tree analysis; decision support;

   Sammanfattning : Potentially polluting shipwrecks containing oil or other hazardous substances pose a threat to the marine environment. This is a global problem and many shipwrecks stem from the Second World War having been deteriorating on the sea floor since then. Only in Swedish waters more than 300 wrecks are estimated to pose an environmental threat. LÄS MER

5. 4. Structural Reliability and Identification with Stochastic Simulation - Application to Railway Mechanics

   Författare :Sadegh Rahrovani; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; model reduction; time-integration; finite element model; sleeper-ballast load characterization; stochastic simulation; Bayesian system identification;

   Sammanfattning : System identification of structures based on measured response data can play a key role in improving reliability based structural designs. However, the experimental limitations of in situ tests and uncertainties of required model complexity together with the inverse nature of system identification give rise to a number of challenging issues. LÄS MER

7. 5. Optimal strategies and information in foraging theory

   Författare :Emma Sernland; Högskolan i Skövde; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Bayesian foraging; information use; public information; prior information; negative binomial distribution; group foraging; decision-making; information updating; leaving strategy; Ecology; Ekologi; NATURAL SCIENCES; NATURVETENSKAP; Other biology; Övrig biologi; Naturvetenskap; Natural sciences; information use; Bayesian foraging; public information; prior information; negative binomial distribution; group foraging; decision-making; information updating; leaving strategy; Ecology; Ekologi;

   Sammanfattning : In this thesis, I present both theoretical and empirical work where we have studied how humans and animals use information in situations where they need to continually update their information on the density of a resource. We have found that the amount of information, and the way the information is presented, are important factors for how well decisions are adapted to current circumstances. LÄS MER