1778793
The competition number of a graph having exactly one hole
Let D be an acyclic digraph. The competition graph of D has the same set of vertices as D and an edge between vertices u and v if and only if there is a vertex x in D such that (u,x) and (v,x) are arcs of D. The competition number of a graph G, denoted by k(G), is the smallest number k such that G together with k isolated vertices is the competition graph of an acyclic digraph. In this paper, we show that the competition number of a graph having exactly one chordless cycle of length at least 4 is at most two. We also give a large family of such graphs whose competition numbers are less than or equal to one.
14022405
The m-step competition graph of a digraph
The competition graph of a digraph was introduced by Cohen in 1968 associated with the study of ecosystems. Since then, the competition graph has been widely studied and many variations have been introduced. In this paper, we define and study the m-step competition graph of a digraph which is another generalization of competition graph.
22820549
Mobility-Aware Mobile Router Selection and Address Management for IPv6 Network Mobility
Network mobility (NEMO) extends IP mobility to moving networks, which are groups of nodes that often constitute a subnet of a mobile router (MR). To realize this collective mobility, there are a number of important issues such as addressing and multihoming. With the proliferation of mobile nodes connected to the Internet, the efficient allocation/deallocation of addresses is becoming a vital requirement. We propose a collaborative address management scheme for network mobility, where the home DHCPv6 agent of a mobile network performs prefix delegation, while the mobile DHCPv6 agent (in the mobile network) allocates the IPv6 address to each mobile node. Also, network mobility with multiple MRs is taken into consideration. To provide a mobile network that has multiple MRs with robust Internet connectivity, we propose mobility-aware mobile router selection schemes. The concept of “mobility awareness” refers to the capability of a moving network in a vehicle (e.g., a train) to pinpoint the most stable Internet connectivity, by choosing the mobile router based on the vehicle’s movement pattern. The simulation shows that the proposed scheme outperforms a round-robin mobile router selection scheme in terms of the amount of carried traffic.
11159214
The impacts of Delphi communication structure on small and medium sized asynchronous groups: preliminary results
Communication structure is a way of improving the effectiveness of group communications by coordinating group members' individual efforts. This study investigates the use of Delphi, a communication structure which has been widely used to collect ideas and opinions from geographically dispersed experts. A new approach in Delphi implementation using asynchronous computer-mediated communication (CMC) is developed. A 2X2 controlled experiment investigates the effect of Delphi structure on small-sized (5-6 members) and medium-sized (10-12 members) asynchronous CMC groups. The group task is to describe the potential applications and impacts of pervasive devices that can track the location of individuals. Preliminary results indicate that the Delphi structure does result in more unique ideas per person than the unstructured condition.