12,660 research outputs found
The existence of periodic solution for infinite dimensional Hamiltonian systems
In this paper, we will consider a kind of infinite dimensional Hamiltonian
system(HS), by the method of saddle point reduction, topology degree and the
index, we will get the existence of periodic solution for (HS)
Rank-frequency relation for Chinese characters
We show that the Zipf's law for Chinese characters perfectly holds for
sufficiently short texts (few thousand different characters). The scenario of
its validity is similar to the Zipf's law for words in short English texts. For
long Chinese texts (or for mixtures of short Chinese texts), rank-frequency
relations for Chinese characters display a two-layer, hierarchic structure that
combines a Zipfian power-law regime for frequent characters (first layer) with
an exponential-like regime for less frequent characters (second layer). For
these two layers we provide different (though related) theoretical descriptions
that include the range of low-frequency characters (hapax legomena). The
comparative analysis of rank-frequency relations for Chinese characters versus
English words illustrates the extent to which the characters play for Chinese
writers the same role as the words for those writing within alphabetical
systems.Comment: To appear in European Physical Journal B (EPJ B), 2014 (22 pages, 7
figures
The Least-core and Nucleolus of Path Cooperative Games
Cooperative games provide an appropriate framework for fair and stable profit
distribution in multiagent systems. In this paper, we study the algorithmic
issues on path cooperative games that arise from the situations where some
commodity flows through a network. In these games, a coalition of edges or
vertices is successful if it enables a path from the source to the sink in the
network, and lose otherwise. Based on dual theory of linear programming and the
relationship with flow games, we provide the characterizations on the CS-core,
least-core and nucleolus of path cooperative games. Furthermore, we show that
the least-core and nucleolus are polynomially solvable for path cooperative
games defined on both directed and undirected network
Giant plexiform neurofibroma with hemorrhage in cranio-maxillofacial region as depicted on CT and MRI
Plexiform neurofibroma (PN) is a rare benign tumor and a special subtype of neurofibromatosis type 1 (NF1). Though the incidence is low, giant PN of the craniomaxillofacial region could result in severe hemifacial hypertrophy which is known as a typical manifestation of NF1 in young children. Here, we retrospectively reported a giant plexiform neurofibroma with hemorrhage in the cranio-maxillofacial region detected by CT and MRI. In addition, a brief review of the relevant literature is presented
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