Fiber surfaces from alternating states

In this paper we define alternating Kauffman states of links and we characterize when the induced state surface is a fiber. In addition, we give a different proof of a similar theorem of Futer, Kalfagianni and Purcell on homogeneous states.Comment: 11 pages, 10 figures; Accepted for publication in Algebraic and Geometric Topolog

Web Acceptance and Usage Model: A Comparison between Goal-directed and Experiential Web Users

In this paper we analyse the Web acceptance and usage between goal-directed users and experiential users, incorporating intrinsic motives to improve the particular and explanatory TAM value –traditionally related to extrinsic motives-. A field study was conducted to validate measures used to operationalize model variables and to test the hypothesised network of relationships. The data analysis method used was Partial Least Squares (PLS).The empirical results provided strong support for the hypotheses, highlighting the roles of flow, ease of use and usefulness in determining the actual use of the Web among experiential and goal-directed users. In contrast with previous research that suggests that flow would be more likely to occur during experiential activities than goal-directed activities, we found clear evidence of flow for goal-directed activities. In particular the study findings indicate that flow might play a powerfulrole in determining the attitude towards usage,intention to useand, in turn,actual Web use among experiential and goal-directed users

Orders of branched covering of links

Let M, M′ be compact oriented 3-manifolds and L′ a link in M′. We prove that, under certain conditions, the topological types of M and (M′,L′) determine the degree of a cyclic covering p : M → M′, branched over L′

Orders and actions of branched coverings of hyperbolic links

Let M, M′ be compact oriented 3-manifolds and L′ a link in M′ whose exterior has positive Gromov norm. We prove that the topological types of M and (M′,L′) determine the degree of a strongly cyclic covering p : M → M′, branched over L′. Moreover, if M′ is an homology sphere then these topological types determine also the covering up to conjugacy