Sökning: "stationary"

Visar resultat 36 - 40 av 705 avhandlingar innehållade ordet stationary.

1. 36. Essays on Fiscal Policy, Private Consumption and Non-Stationary Panel Data

   Författare :Kristian Jönsson; Nationalekonomiska institutionen; []
   Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; ekonomiska system; ekonomisk politik; economic systems; economic theory; econometrics; Economics; Cross-Sectional Dependence; Output Convergence; Unit Root; Stationarity; Panel Data; Government Consumption; Non-Keynesian Effects; Private Consumption; economic policy; Nationalekonomi; ekonometri; ekonomisk teori; Fiscal Policy;

   Sammanfattning : In the first essay of this thesis, we examine whether the effects of fiscal expansions and contractions exert a symmetric influence on the relationship between fiscal policy and private consumption. Our results indicate a considerable asymmetry across fiscal expansions and contractions. LÄS MER

3. 37. Heat Balance Modeling of a Stationary Fluidized-Bed Furnace Burning Biomass

   Författare :Fredrik Niklasson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; mixing; modeling; biomass; dispersion; heat balance; fluidized bed boiler;

   Sammanfattning : The influence of biomass fuel properties on the heat balance of the bottom region (bed and splash zone) of a commercial-scale bubbling fluidized-bed furnace is investigated theoretically and experimentally. The experiments have been carried out at the Chalmers 12 MWth research boiler, operated under non-circulating conditions during most of the experiments. LÄS MER

4. 38. Towards Robust and Adaptive Machine Learning : A Fresh Perspective on Evaluation and Adaptation Methodologies in Non-Stationary Environments

   Författare :Firas Bayram; Bestoun S. Ahmed; Patrick Glauner; Karlstads universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; machine learning; concept drift; covariate shift; performance robustness; evaluation methodology; adaptive learning; Computer Science; Datavetenskap;

   Sammanfattning : Machine learning (ML) has become ubiquitous in various disciplines and applications, serving as a powerful tool for developing predictive models to analyze diverse variables of interest. With the advent of the digital era, the proliferation of data has presented numerous opportunities for growth and expansion across various domains. LÄS MER

5. 39. Modelling effects of flame development on stationary and oscillating premixed turbulent combustion

   Författare :Pratap Sathiah; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; flame development; Keywords: Premixed turbulent flame; Flame Speed Closure model;

   Sammanfattning : The vast majority of contemporary models of premixed turbulent flames applied to multi-dimensional RANS numerical simulations of combustion in gas turbine engines and aero-engine afterburners focus on fully-developed flames, characterized by fully-developed turbulent diffusivity, thickness, and burning velocity. However, abundant experimental data obtained from statistically stationary premixed flames clearly show that a typical turbulent flame develops as it is convected by mean flow from a stabilization zone. LÄS MER

7. 40. Modeling Auto-Ignition, Flame Propagation and Combustion in Non-Stationary Turbulent Sprays

   Författare :Anders Karlsson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; auto-ignition; transient; flame propagation; turbulence; spray formation; prediction; stirred reactor approximation; model; reduced chemistry; combustion;

   Sammanfattning : This thesis focuses on detailed numerical studies of spray formation, auto-ignition, envelope flame development and combustion in a simple two-dimensional axi-symmetric geometry. A Lagrangian -- Eulerian formulation is used to analyze the droplet motion and gas flow field. LÄS MER