2867815
Matchings and matching extensions in graphs
Abstract Let G be a graph with a perfect matching and k be an integer such that 1 ⩽ k vbV ( G ) vb /2. Then G is said to be k -extendable if every matching of size k in G extends to a perfect matching of G . Plummer (1994) proved that every (2 k + 1)-connected K 1,3 -free graph of even order is k -extendable. In this paper, it was proved that every (2 k + n − 2)-connected K 1, n -free graph of even order is k -extendable. Also, an answer to the problem of characterizing maximal k -extendable graphs posted by Plummer (1994) and Saito (1989/90) is given. Besides, we show that a regular graph of even order belongs to the first class if its any two odd cycles have at least a vertex in common.
27005423
Binding number and toughness for matching extension
Abstract A graph G of even order is said to be k -extendable if every matching of size k in G can be extended to a 1-factor of G . Plummer (1988) showed that a graph G is k -extendable if tough ( G ) > k , and we here prove that G is also k -extendable if bind ( G ) > max {k, (7k + 13)/12}.
31774377
Factors in graphs with odd-cycle property
Abstract We present some conditions for the existence of a ( g , f )-factor or a ( g , f )-parity factor in a graph G with the odd-cycle property that any two odd cycles of G either have a vertex in common or are joined by an edge.
2344024
From latent semantics to spatial hypertext—an integrated approach
In this paper, we introduce an integrated approach to the development of spatial hypertext. This approach brings together several theories and techniques concerning semantic structures, and streamlines the transformation from implicit semantic structures to a semantic space rendered in virtual reality. Browsing and querying become natural, inherent, and compatible activities within the same semantic space. The overall design principle is based on the theory of cognitive maps. Techniques such as latent semantic indexing, Pathfinder network scaling, and virtual reality modelling are used in harmony. The value of this integrated approach is discussed based on initial results of a recent empirical study, which suggests that the spatial metaphor is intuitive and particularly useful when dealing with implicit information structures, or when a highly flexible and extensible virtual environment is required. Search strategies in association with the spatial hypertext and further work are also discussed.
38249565
An extreme problem concerning k-arc-cyclic property for a class of tournaments
B. Alspach has proved that a regular tournament is arc-pancyclic. Zhu and Tian proved that if a tournament T = (V, A) with vertex set V, arc set A and order p satisfies that for any arc (vi, vj) of T, if d+(vj)+d-(vi)⩾p−2, then T is arc-pancyclic, where p⩾7. In this paper we study an extreme problem concerning the k-arc-cyclic property for a class of tournaments. 
 
We say that a tournament T=(V, A) satisfies the condition O(p, q) if d+(v)+d-(u)⩾p−q for any arc (u, v) of T, where q is a positive integer and |V|=p. Zhu, Tian, Chen and Zhang proved that if a tournament T satisfies the condition O(p, q) and p⩾3q+3, then T is arc-pancyclic. Let S(p, q) be the set{T=(V, A): T is a tournament with p vertices and T satisfies the condition O(p, q)}; let Ck(u, v) be the set {cycles of T with length k using the arc (u, v)}. The aim of this paper is that for a given integer q, we can find an integer m(q, k) such that if p⩾m(q, k), then for any T ϵ S(p, q), T is k-arc-cyclic; if p⩽m(q, k)−1, then there exists T ϵ S(p, q) such that T is not k-arc-cyclic. We have found that m(q, 4)=5q−7, and m(q, 5)=⌊p∗(q)⌋+1 or ⌈p∗(q)⌉+1, where p∗(q)=(1+312)q−(1+43·3 12).
19946044
On edge-Hamiltonian property of Cayley graphs
Abstract Let G be a group generated by X . A Cayley graph over G is defined as a graph G ( X ) whose vertex set is G and whose edge set consists of all unordered pairs [ a,b ] with a , b ϵ G and a -1 b ϵ X ∩ X -1 , where X -1 denotes the set { x -1 ∣ x ϵ X }. When X is a minimal generating set or each element of X is of even order, it can be shown that G ( X ) is Hamiltonian if it is edge-Hamiltonian. Hence every Cayley graph of order a power of 2 is edge-Hamiltonian.
21308144
EmoEars: An Emotion Recognition System for Mandarin Speech
In this paper, an emotion recognition system for mandarin speech is presented. Five basic human emotions including angry, fear, happy, neutral and sad are investigated. The recognizer is based on neural network with OCON and ACON architecture. Some novel feature selection methods are also added as optional tool to enhance the efficiency and classification accuracy. The system can train speaker dependent emotion speech model through online emotional utterance recording. Experiment results show that emotion can be recognized through neural network model, the best mean accuracy is 86.7%. In addition, the feature selection module is effective to reduce the compute load and increase the generalization ability of the recognizer.
41020572
Cycle Partitions in Graphs
In this paper, we prove that every graph contains a cycle intersecting all maximum independent sets. Using this, we further prove that every graph with stability number α is spanned by α disjoint cycles. Here, the empty set, the graph of order 1 and the path of order 2 are all considered as degenerate cycles.