‎In this paper first we define the morphism between geometric spaces in two different types‎. ‎We construct two categories of $uu$ and $l$ from geometric spaces then investigate some properties of the two categories‎, ‎for instance $uu$ is topological‎. ‎The relation between hypergroups and geometric spaces is studied‎. ‎By constructing the category $qh$ of $H_{v}$-groups we answer the question...

Categorization models based on laboratory research focus on a narrower range of explanatory constructs than appears necessary for explaining the structure of natural categories. This mismatch is caused by the reliance on classification as the basis of laboratory studies. Category representations are formed in the process of interacting with category members. Thus, laboratory studies must explor...

Based on unbalanced panel dates of 4060 companies listed from 2003 2007 in Shanghai and Shenzhen Stock Markets, this paper empirically studies the degree of product market competition, the relationship between cash dividends distribution tendency and cash dividends policy. Results show that controlling shareholders have significant motivation to distribute cash dividends, and this kind of incen...

Article history: Received 9 April 2009 Available online 17 September 2010 Communicated by Luchezar L. Avramov Dedicated to Professor Claus Michael Ringel on the occasion of his sixty-fifth birthday MSC: 18G25 18E30 16E65

We introduce the concept of combed graphs and present an ear decomposition theorem for this class of graphs. This theorem includes the well known ear decomposition theorem for matching covered graphs proved by Lovász and Plummer. Then we use the ear decomposition theorem to show that any two edges of a 2-connected combed graph lie in a balanced circuit of an equivalent combed graph. This result...