Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • 1990-1994  (8)
Source
Material
Years
Year
Person/Organisation
Keywords
  • 1
    Electronic Resource
    Electronic Resource
    Generalized sum graphs (1992)
    Springer
    Graphs and combinatorics 8 (1992), S. 23-29 
    Details
    ISSN: 1435-5914
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science , Mathematics
    Notes: Abstract Harary [8] calls a finite, simple graphG asum graph if one can assign to eachv i ∈V(G) a labelx i so that{v i ,v j }∈E(G) iffx i +x j =x k for somek. We generalize this notion by replacing “x i +x j ” with an arbitrary symmetric polynomialf(x i ,x j ). We show that for eachf, not all graphs are “f-graphs”. Furthermore, we prove that for everyf and every graphG we can transformG into anf-graph via the addition of |E(G)| isolated vertices. This result is nearly best possible in the sense that for allf and for $$ \leqslant \frac{1}{2}\left( {\begin{array}{*{20}c} n \\ 2 \\ \end{array} } \right)$$ , there is a graphG withn vertices andm edges which, even after the addition ofm-O(n logn) isolated vetices, is not andf-graph.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01271705
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    AlmostH-factors in dense graphs (1992)
    Springer
    Graphs and combinatorics 8 (1992), S. 95-102 
    Details
    ISSN: 1435-5914
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science , Mathematics
    Notes: Abstract The following asymptotic result is proved. For every fixed graphH withh vertices, any graphG withn vertices and with minimum degree $$d \geqslant \frac{{\chi (H) - 1}}{{\chi (H)}}n$$ contains (1−o(1))n/h vertex disjoint copies ofH.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02350627
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Packing of partial designs (1994)
    Springer
    Graphs and combinatorics 10 (1994), S. 11-18 
    Details
    ISSN: 1435-5914
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science , Mathematics
    Notes: Abstract We say that two hypergraphsH 1 andH 2 withv vertices eachcan be packed if there are edge disjoint hypergraphsH 1 ′ andH 2 ′ on the same setV ofv vertices, whereH i ′ is isomorphic toH i.It is shown that for every fixed integersk andt, wheret≤k≤2t−2 and for all sufficiently largev there are two (t, k, v) partial designs that cannot be packed. Moreover, there are twoisomorphic partial (t, k, v)-designs that cannot be packed. It is also shown that for every fixedk≥2t−1 and for all sufficiently largev there is a (λ1,t,k,v) partial design and a (λ1,t,k,v) partial design that cannot be packed, where λ1 λ2≤O(v k−2t+1 logv). Both results are nearly optimal asymptotically and answer questions of Teirlinck. The proofs are probabilistic.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01202465
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Transversal numbers of uniform hypergraphs (1990)
    Springer
    Graphs and combinatorics 6 (1990), S. 1-4 
    Details
    ISSN: 1435-5914
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science , Mathematics
    Notes: Abstract The transversal numberτ(H) of a hypergraphH is the minimum cardinality of a set of vertices that intersects all edges ofH. Fork ≥ 1 definec k =sup τ(H)/(m + n), whereH ranges over allk-uniform hypergraphs withn vertices andm edges. Applying probabilistic arguments we show thatc k = (1 +o(1))log e k/k. This settles a problem of Tuza.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01787474
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Spanning subgraphs of random graphs (1992)
    Springer
    Graphs and combinatorics 8 (1992), S. 91-94 
    Details
    ISSN: 1435-5914
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science , Mathematics
    Notes: Abstract We propose a problem concerning the determination of the threshold function for the edge probability that guarantees, almost surely, the existence of various sparse spanning subgraphs in random graphs. We prove some bounds and demonstrate them in the cases of ad-cube and a two dimensional lattice.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01271712
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    The maximum number of Hamiltonian paths in tournaments (1990)
    Springer
    Combinatorica 10 (1990), S. 319-324 
    Details
    ISSN: 1439-6912
    Keywords: 05 C 20 ; 05 C 35 ; 05 C 38
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Abstract Solving an old conjecture of Szele we show that the maximum number of directed Hamiltonian paths in a tournament onn vertices is at mostc · n 3/2 · n!/2 n−1, wherec is a positive constant independent ofn.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02128667
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Star arboricity (1992)
    Springer
    Combinatorica 12 (1992), S. 375-380 
    Details
    ISSN: 1439-6912
    Keywords: 05 C 70 ; 60 C 05
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Abstract Astar forest is a forest all of whose components are stars. Thestar arboricity, st(G) of a graphG is the minimum number of star forests whose union covers all the edges ofG. Thearboricity, A(G), of a graphG is the minimum number of forests whose union covers all the edges ofG. Clearlyst(G)≥A(G). In fact, Algor and Alon have given examples which show that in some casesst(G) can be as large asA(G)+Ω(logΔ) (where Δ is the maximum degree of a vertex inG). We show that for any graphG, st(G)≤A(G)+O(logΔ).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01305230
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Book
    Book
    ¬The¬ probabilistic method (1992)
    New York u.a. :Wiley,
    Details
    Title: ¬The¬ probabilistic method
    Author: Alon, Noga
    Contributer: Spencer, Joel H. , Erdos, Paul
    Publisher: New York u.a. :Wiley,
    Year of publication: 1992
    Pages: 254 S.
    Type of Medium: Book
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    ZIB Catalog
    Zuse Institute Berlin get availability status
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...