Sökning: "Inversion method"

Visar resultat 1 - 5 av 107 avhandlingar innehållade orden Inversion method.

  1. 1. Inversion and Joint Inversion of Electromagnetic and Potential Field Data

    Författare :Jochen Kamm; Ari Tryggvason; Laust B Pedersen; Mehrdad Bastani; Douglas Oldenburg; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Inversion; Electromagnetic methods; Joint inversion; Potential Field methods; Inversion; Elektromagnetische Verfahren; Joint-Inversion; Potentialverfahren; Geofysik med inriktning mot fasta jordens fysik; Geophysics with specialization in Solid Earth Physics;

    Sammanfattning : In this thesis, four inversion problems of different scale and difficulty are solved. Two of them are electromagnetic inverse problems. Two more are joint inversion problems of potential field data and other types of data. LÄS MER

  3. 2. Quantifying the Seismic Response of Underground Structures via Seismic Full Waveform Inversion : Experiences from Case Studies and Synthetic Benchmarks

    Författare :Fengjiao Zhang; Christopher Juhlin; Ari Tryggvason; Yanghua Wang; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; full waveform inversion; waveform tomography; CO2 monitoring; CO2 sequestration; time lapse seismic; Inversion; Geofysik med inriktning mot fasta jordens fysik; Geophysics with specialization in Solid Earth Physics;

    Sammanfattning : Seismic full waveform inversion (waveform tomography) is a method to reconstruct the underground velocity field in high resolution using seismic data. The method was first introduced during the 1980’s and became computationally feasible during the late 1990’s when the method was implemented in the frequency domain. LÄS MER

  4. 3. Efficient carbohydrate synthesis by controlled inversion strategies

    Författare :Hai Dong; Olof Ramström; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Carbohydrate Chemistry; Carbohydrate Protection; Epimerization; Inversion; Dynamic; Regioselective Control; Neighboring Group Participation; Organic chemistry; Organisk kemi;

    Sammanfattning : The Lattrell-Dax method of nitrite-mediated substitution of carbohydrate triflates is an efficient method to generate structures of inverse configuration. In this study it has been demonstrated that a neighboring equatorial ester group plays a highly important role in this carbohydrate epimerization reaction, inducing the formation of inversion compounds in good yields. LÄS MER

  5. 4. Three-dimensional forward modelling and inversion of controlled-source electromagnetic data using the edge-based finite-element method

    Författare :Paula Rulff; Thomas Kalscheuer; Michael Becken; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Applied geophysics; Controlled-source electromagnetics; Numerical modelling; Finite-element method; Geophysical inversion; Geofysik med inriktning mot fasta jordens fysik; Geophysics with specialization in Solid Earth Physics;

    Sammanfattning : Electromagnetic geophysical methods are applied to investigate anomalous subsurface structures exhibiting contrasts in electrical resistivity, as for example in mineral exploration or geothermal areas. When evaluating electromagnetic data, one big challenge is to account for full three-dimensional measurement setups and subsurface scenarios. LÄS MER

  7. 5. Resistivity investigation and monitoring for detection of internal erosion and anomalous seepage in embankment dams

    Författare :Pontus Sjödahl; Teknisk geologi; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Hydrogeologi; teknisk geologi; internal erosion; Hydrogeology; geographical and geological engineering; time-lapse inversion; inversion; monitoring; modelling; resistivity; detection; leakage; seepage; teknisk geografi; embankment dam;

    Sammanfattning : Methods for monitoring seepage and detecting internal erosion are essential for the safety evaluation of embankment dams. Internal erosion is one of the major reasons for embankment dam failures, and there are several tenths of thousands of large embankment dams in the world. LÄS MER