Sökning: "Jan Lundberg"

Visar resultat 6 - 10 av 20 avhandlingar innehållade orden Jan Lundberg.

1. 6. Aneuploidy compensatory mechanisms and genome-wide regulation of gene expression in Drosophila melanogaster

   Författare :Lina Lundberg; Jan Larsson; Brian Oliver; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Genome-wide gene regulation; aneuploidy; buffering; HP1a; POF; SETDB1; Su var 3-9; MSL; roX; genetik; Genetics;

   Sammanfattning : Stimulation or repression of gene expression by genome-wide regulatory mechanisms is an important epigenetic regulatory function which can act to efficiently regulate larger regions or specific groups of genes, for example by compensating for loss or gain of chromosome copy numbers. In Drosophila melanogaster there are two known chromosome-wide regulatory systems; the MSL complex, which mediates dosage compensation of the single male X-chromosome and POF, which stimulates expression from the heterochromatic 4th chromosome. LÄS MER

3. 7. Two-Level Multi-Objective Genetic Algorithm for Risk-Based Life Cycle Cost Analysis

   Författare :Yamur K. Al-Douri; Uday Kumar; Jan Lundberg; Hussan Hamodi; Ahmed Al-Dubai; Luleå tekniska universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Artificial intelligence AI ; Life cycle cost LCC ; Machine learning ML ; Multi-objective genetic algorithm MOGA ; Risk-based life cycle cost LCC ; Tunnel fans; Two-level system; Operation and Maintenance Engineering; Drift och underhållsteknik;

   Sammanfattning : Artificial intelligence (AI) is one of the fields in science and engineering and encompasses a wide variety of subfields, ranging from general areas (learning and perception) to specific topics, such as mathematical theorems. AI and, specifically, multi-objective genetic algorithms (MOGAs) for risk-based life cycle cost (LCC) analysis should be performed to estimate the optimal replacement time of tunnel fan systems, with a view towards reducing the ownership cost and the risk cost and increasing company profitability from an economic point of view. LÄS MER

4. 8. Non-destructive measurement of near-surface cracks in railheads : with focus on ultrasonic inspections

   Författare :Rayendra Anandika; Jan Lundberg; Paul Wilcox; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; rail inspection; phased array; ultrasonic testing; eddy current testing; surface cracks; non-destructive testing; NDT; railway; condition monitoring; Drift och underhållsteknik; Operation and Maintenance;

   Sammanfattning : Near-surface cracks in railhead that caused by rolling contact fatigue (RCF) is one of a kind rail defects that degrade rail track quality. Dependent on the trail load, the cracks can reach to severe level quickly. LÄS MER

5. 9. Effects of top-of-rail friction modifiers on the friction, wear and cracks of railway rails

   Författare :Saad Ahmed Khan; Jan Lundberg; Rolf Dollevoet; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Drift och underhållsteknik; Operation and Maintenance;

   Sammanfattning : The railway is an economical and environmentally friendly mode of transport for long distances and heavy loads. The demands on the operators are increasing with increased competition in the market, and therefore they are currently demanding more track capacity. In the short term, the existing network is expected to deliver the increased capacity. LÄS MER

7. 10. Collaborative conceptual design methods in the context of the Swedish deregulated railway market : From the perspectives of maintenance, infrastructure management, product provision, and research

   Författare :Anna Malou Petersson; Jan Lundberg; Tobias Larsson; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Drift och underhållsteknik; Operation and Maintenance;

   Sammanfattning : As a result of the deregulation of the Swedish railway market, the differentfunctions involved during the life cycle of railway products have been spreadout over different actors. The trigger for the work presented in this thesis wasthe insight that, since function-specific knowledge of the railway in Swedenbelongs to different organizations, special efforts would be needed to achieve aholistic picture of a railway product during the conceptual design phase. LÄS MER