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On Partial ovoids of Hermitian surfaces
No full textLower bounds for the size of a complete partial ovoid in a non-degenerate Hermitian surface are obtained. For even characteristic, a sharp bound is obtained and all examples of this size are described. Next, a general construction method for locally hermitian partial ovoids is explained, which leads to interesting small examples. Finally, a conjecture is given for the size of the largest complete strictly partial ovoid. By using partial derivation, several examples of complete strictly partial ovoids of this size are provide
Complete spans on Hermitian varieties
No full textLet L be a general linear complex in PG(3, q) for any prime power q. We show that when GF(q) is extended to GF(q(2)), the extended lines of L cover a non-singular Hermitian surface H congruent to H(3, q(2)) of PG(3, q(2)). We prove that if S is any symplectic spread PG(3, q), then the extended lines of this spread form a complete (q(2) + 1)-span of H. Several other examples of complete spans of H for small values of q are also discussed. Finally, we discuss extensions to higher dimensions, showing in particular that a similar construction produces complete (q(3) + 1)-spans of the Hermitian variety H(5, q(2))
On pairs of permutable Hermitian surfaces
No full textAbstractWe investigate the intersection R of two permutable Hermitian surfaces of PG(3,q2), q odd. We show that R is a determinantal variety. From the combinatorial point of view R comprises a complete (q2+1)-span of the two corresponding Hermitian surfaces
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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