Sökning: "Joakim Ekström"

Hittade 4 avhandlingar innehållade orden Joakim Ekström.

  1. 1. Contributions to the Theory of Measures of Association for Ordinal Variables

    Författare :Joakim Ekström; Rolf Larsson; Albert Satorra; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Statistics; Statistik; Statistics; statistik;

    Sammanfattning : In this thesis, we consider measures of association for ordinal variables from a theoretical perspective. In particular, we study the phi-coefficient, the tetrachoric correlation coefficient and the polychoric correlation coefficient. LÄS MER

  2. 2. Designing Urban Road Congestion Charging Systems : Models and Heuristic Solution Approaches

    Författare :Joakim Ekström; Jan Lundgren; Anders Karlström; Linköpings universitet; []
    Nyckelord :transport modeling; congestion pricing; network design; bi-level optimization; toll locations; traffic assignment; user equilibrium; collection cost; TECHNOLOGY; TEKNIKVETENSKAP;

    Sammanfattning : The question of how to design a congestion pricing scheme is difficult to answer and involves a number of complex decisions. This thesis is devoted to the quantitative parts of designing a congestion pricing scheme with link tolls in an urban car traffic network. LÄS MER

  3. 3. Optimization Approaches for Design of Congestion Pricing Schemes

    Författare :Joakim Ekström; Jan Lundgren; Richard Connors; Linköpings universitet; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : In recent years, there has been a growing interest in congestion pricing as a tool for solving traffic congestion problems in urban areas. However, the transportation system is complex and to design a congestion pricing scheme, i.e. to decide where and how much to charge the road users, is not trivial. LÄS MER

  4. 4. Emission estimation based on traffic models and measurements

    Författare :Nikolaos Tsanakas; Jan T. Lundgren; Joakim Ekström; Johan Olstam; Marcus Gerstenberger; Linköpings universitet; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : Traffic congestion increases travel times, but also results in higher energy usage and vehicular emissions. To evaluate the impact of traffic emissions on environment and human health, the accurate estimation of their rates and location is required. LÄS MER