1,722,590 research outputs found
The Rossi-Vergne theorem and constant coefficient PDEs on the Heisenberg group
No full textQuaderni di Matematica,
Improved Parameterized Complexity of Happy Set Problems
Full text linkWe present fixed-parameter tractable (FPT) algorithms for two problems,
Maximum Happy Set (MaxHS) and Maximum Edge Happy Set (MaxEHS)--also known as
Densest k-Subgraph. Given a graph and an integer , MaxHS asks for a set
of vertices such that the number of with
respect to is maximized, where a vertex is happy if and all its
neighbors are in . We show that MaxHS can be solved in time
and , where and denote the
and the of , respectively.
This resolves the open questions posed in literature. The MaxEHS problem is an
edge-variant of MaxHS, where we maximize the number of ,
the edges whose endpoints are in . In this paper we show that MaxEHS can be
solved in time and
, where
and denote the
and the of , respectively, and is
some computable function. This result implies that MaxEHS is also
fixed-parameter tractable by
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
- …
