Sökning: "Johan Casselgren"

Visar resultat 1 - 5 av 12 avhandlingar innehållade orden Johan Casselgren.

  1. 1. Road surface characterization using near infrared spectroscopy

    Författare :Johan Casselgren; Matti Kutila; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Spektroskopi; Väglagsklassificering; Friktion; Väglagskarakterisering; Experimental Mechanics; Experimentell mekanik;

    Sammanfattning : This thesis presents a technology and method for classifying and characterizing different road conditions such as dry asphalt and asphalt covered with water, ice and snow. The method uses light sources of different wavelengths to illuminate the road surface and a detector to measure the reflected light from the road surfaces, dependent on how the surface have absorbed, scattered and polarized the light it is possible to classify the road condition. LÄS MER

  3. 2. Road surface classification using near infrared spectroscopy

    Författare :Johan Casselgren; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Experimentell mekanik; Experimental Mechanics;

    Sammanfattning : Statistics shows that most traffic accidents with fatal outcome can be related to slippery road conditions. The most hazardous road conditions are the ones that are hard for the driver to detect and that appears sudden on the road. LÄS MER

  4. 3. On some graph coloring problems

    Författare :Carl Johan Casselgren; Roland Häggkvist; Svante Linusson; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; List coloring; interval edge coloring; coloring graphs from random lists; biregular graph; avoiding arrays; Latin square; scheduling; Discrete mathematics; Diskret matematik; Mathematics; matematik;

    Sammanfattning : .... LÄS MER

  5. 4. Edge Precoloring Extension of Trees

    Författare :Fikre Bogale Petros; Carl Johan Casselgren; Armen Asratian; Lars-Daniel Öhman; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : Given a set of k colors and a graph G with a subset S of precolored edges (a partial k-edge coloring of G), we consider the problem of determining whether G has a proper edge coloring of G with the same k colors (an extension of the partial coloring) where the colors of edges in S are not changed. If such a coloring exists, then the partial k-coloring is called extendable. LÄS MER

  7. 5. Experiments and simulations on the mechanics of ice and snow

    Författare :Hassan Bahaloohoreh; Johan Casselgren; Simon Larsson; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Experiments; Sintering force; Capillar bridge; liquid film; Discrete Element Method; Particles; Experimentell mekanik; Experimental Mechanics;

    Sammanfattning : In this study, experiments and simulations were conducted to investigate ice and snow. The ice sintering force as a function of temperature, pressing force (contact load), contact duration, and particle size during the primary stage of sintering was formulated using experimental methods along with an approximate, semi-analytic, close-form solution. LÄS MER