Sökning: "edge length"

Visar resultat 1 - 5 av 94 avhandlingar innehållade orden edge length.

  1. 1. Forest edges in boreal landscapes - factors affecting edge influence

    Författare :Ulrika Jansson; Per-Anders Esseen; Mats Nilsson; Timo Kuuluvainen; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; aerial photographs; edge contrast; edge density; edge length; fetch size; forest fragmentation; lichen growth; line intersect sampling; pendulous lichen; photo interpretation; skogskant; flygbild; kantlängd; lav; Terrestrial ecology; Terrestisk ekologi; ekologisk botanik; Ecological Botany;

    Sammanfattning : The boreal forest in Fennoscandia has been subjected to major loss and fragmentation of natural forests due to intensive forestry. This has resulted in that forest edges are now abundant and important landscape features. Edges have documented effects on the structure, function and biodiversity in forests. LÄS MER

  3. 2. A Theoretical Study: The Connection between Stability of Single-Walled Carbon Nanotubes and Observed Products

    Författare :Daniel Hedman; Andreas Larsson; Sven Öberg; Krisztián Kordás; Luleå tekniska universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Single-walled carbon nanotubes; density functional theory; catalytic chemical vapor deposition; chirality-specific growth; stability; length; diameter; edge; chirality; Applied Physics; Tillämpad fysik;

    Sammanfattning : Over the past 20 years’ researchers have tried to utilize the remarkable properties of single-walled carbon nanotubes (SWCNTs) to create new high-tech materials and devices, such as strong light-weight composites, efficient electrical wires and super-fast transistors. But the mass production of these materials and devices are still hampered by the poor uniformity of the produced SWCNTs. LÄS MER

  4. 3. Interaction between electronic and vibrational edge states in graphene

    Författare :Anton Vikström; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; collective excitations; quantum acous- tics; quantum Hall effect; edge waves; graphene; solitons;

    Sammanfattning : A sheet of graphene in a magnetic field perpendicular to the sheet has electronic edge states with nonzero velocities. These edge states are localized to the edge of the sheet on the order of the magnetic length. LÄS MER

  5. 4. Lower Bounds and Trade-offs in Proof Complexity

    Författare :Susanna F. de Rezende; Jakob Nordström; Amit Chakrabarti; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Proof complexity; trade-offs; lower bounds; size; length; space; Computer Science; Datalogi;

    Sammanfattning : Propositional proof complexity is a field in theoretical computer science that analyses the resources needed to prove statements. In this thesis, we are concerned about the length of proofs and trade-offs between different resources, such as length and space. LÄS MER

  7. 5. On linear graph invariants related to Ramsey and edge numbers : or how I learned to stop worrying and love the alien invasion

    Författare :Oliver Krüger; Jörgen Backelin; Alexander Engström; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Ramsey number; edge number; minimal Ramsey graph; independence number; clique number; Turán s theorem; crochet pattern; H13-pattern; linear graph invariant; triangle-free graph; Mathematics; matematik;

    Sammanfattning : In this thesis we study the Ramsey numbers, R(l,k), the edge numbers, e(l,k;n) and graphs that are related to these. The edge number e(l,k;n) may be defined as the least natural number m for which all graphs on n vertices and less than m edges either contains a complete subgraph of size l or an independent set of size k. LÄS MER