Sökning: "Linear time trend"

Visar resultat 1 - 5 av 54 avhandlingar innehållade orden Linear time trend.

  1. 1. Validation and time series analysis of global stratospheric data sets

    Författare :Ashley Jones; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; OSIRIS; MIPAS; remote sensing; data assimilation; Trend; stratosphere; ozone; linear regression; Odin; validation;

    Sammanfattning : The depletion of ozone from the stratosphere and the impact of global warming have been identified as phenomena caused as a result of anthropogenic activity. Scientists are thus trying to find quicker and more reliable ways to analyse these environmental problems. LÄS MER

  3. 2. Seasonal Adjustment and Dynamic Linear Models

    Författare :Can Tongur; Daniel Thorburn; Sune Karlsson; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Dynamic linear models; DLM; direct and indirect seasonal adjustment; relative efficiency; Huber loss function; Polls of polls; Wiener process; Swedish elections; Statistics; statistik;

    Sammanfattning : Dynamic Linear Models are a state space model framework based on the Kalman filter. We use this framework to do seasonal adjustments of empirical and artificial data. A simple model and an extended model based on Gibbs sampling are used and the results are compared with the results of a standard seasonal adjustment method. LÄS MER

  4. 3. Removal processes in sewage treatment plants : Sludge quality and treatment efficiency of structurally diverse organic compounds

    Författare :Ulrika Olofsson; Peter Haglund; Staffan Lundstedt; Juliane Hollender; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Environmetrics; flame retardants; GCxGC; non-targeted screening; mass flow; metals; plasticizers; poorly removed contaminants; POP; PPCP; prediction; Principal Component Analysis; removal efficiency; sewage; sewage treatment plants; sludge; sludge adsorption; sources; time-trend analysis; Environmental chemistry; Miljökemi;

    Sammanfattning : Large and ever-increasing numbers of chemicals, including large quantities of a broad spectrum of organic compounds are used in modern society. More than 30 000 of the more than 100 000 chemical substances registered in the EU are estimated to be daily used, of which many will be discharged into the waste-streams handled by municipal sewage treatment plants (STPs). LÄS MER

  5. 4. Essays on Energy Demand and Household Energy Choice

    Författare :Amin Karimu; Runar Brännlund; Jonas Nordström; Umeå universitet; []
    Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; Choice Probability; derivatives; energy policy; gasoline demand; propensity score; tax simulation; unobserved trend; nationalekonomi; Economics;

    Sammanfattning : This thesis consists of four self-contained papers related to energydemand and household cooking energy.Paper [I] examine the impact of price, income and non-economicfactors on gasoline demand using a structural time series model. LÄS MER

  7. 5. Latent variable based computational methods for applications in life sciences : Analysis and integration of omics data sets

    Författare :Max Bylesjö; Johan Trygg; Tormod Naes; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Chemometrics; orthogonal projections to latent structures; OPLS; O2PLS; K-OPLS; kernel-based; non-linear; regression; classification; Populus; Chemistry; Kemi;

    Sammanfattning : With the increasing availability of high-throughput systems for parallel monitoring of multiple variables, e.g. levels of large numbers of transcripts in functional genomics experiments, massive amounts of data are being collected even from single experiments. LÄS MER