33972996
Chromatic equivalence classes of certain cycles with edges
Abstract Let P(G) denote the chromatic polynomial of a graph G . Two graphs G and H are chromatically equivalent, written G∼H , if P(G)=P(H) . A graph G is chromatically unique if for any graph H , G∼H implies that G is isomorphic with H . In this paper, we give the necessary and sufficient conditions for a family of generalized polygon trees to be chromatically unique.
11039476
On the chromatic uniqueness of certain bipartite graphs
Let K(p, q), p ⩽ q, denote the complete bipartite graph in which the two partite sets consist of p and q vertices, respectively. We denote by K-r(p, q), the family of all graphs obtained by deleting any r distinct edges from K(p, q). Teo and Koh showed that K-1(p, q) is chromatically unique (in short χ-unique) for all p, q such that 3 ⩽ p ⩽ q. In this paper, we obtain a sufficient condition for a graph in K-2(p, q) to be χ-unique. Using this result, we then prove that each graph in K-2(p, p + d) is χ-unique for p ⩾ 4and 0 ⩽ d ⩽ 3. For d ⩾ 4, the graphs in K-2(p, q + d) are χ-unique if p > (A + √B)/4d2, where A and B are polynomials in d. We also show that each graph (≇K(4, 4) – K(1, 3)) in K-3(p, p + d) is χ-unique, for p ⩾ 4 and d=0, 1; and all graphs in K-3(p, p + 2) are χ-unique if and only if all graphs in K-4(p + 1, p + 1) are χ-unique, where p ⩾ 4. Finally we prove that every graph in K-4(p, p + 1) is χ-unique for p ⩾ 5.
6604689
Chromaticity of certain tripartite graphs identified with a path
For a graph G, let P(G) be its chromatic polynomial. Two graphs G and H are chromatically equivalent if P(G)=P(H). A graph G is chromatically unique if P(H)=P(G) implies that [email protected]?G. In this paper, we classify the chromatic classes of graphs obtained from K"2","2","[email protected]?P"m(m>=3), (K"2","2","2-e)@?P"m(m>=5) and (K"2","2","2-2e)@?P"m(m>=6) by identifying the end-vertices of the path P"m with any two vertices of K"2","2","2, K"2","2","2-e and K"2","2","2-2e, respectively, where e and 2e are, respectively, an edge and any two edges of K"2","2","2. As a by-product of this, we obtain some families of chromatically unique and chromatically equivalent classes of graphs.
2551506
Chromatic Equivalence Classes of Certain Generalized Polygon Trees, II
Let P(G) denote the chromatic polynomial of a graph G. Two graphs G and H are chromatically equivalent, if P(G)=P(H). A set of graphs S is called a chromatic equivalence class if for any graph H that is chromatically equivalent with a graph G in S, then [email protected]?S. Peng et al. (Discrete Math. 172 (1997) 103-114), studied the chromatic equivalence classes of certain generalized polygon trees. In this paper, we continue that study and present a solution to Problem 2 in Koh and Teo (Discrete Math. 172 (1997) 59-78).
17328688
Improved Dataset Characterisation for Meta-learning
This paper presents new measures, based on the induced decision tree, to characterise datasets for meta-learning in order to select appropriate learning algorithms. The main idea is to capture the characteristics of dataset from the structural shape and size of decision tree induced from the dataset. Totally 15 measures are proposed to describe the structure of a decision tree. Their effectiveness is illustrated through extensive experiments, by comparing to the results obtained by the existing data characteristics techniques, including data characteristics tool (DCT) that is the most wide used technique in meta-learning, and Landmarking that is the most recently developed method.
18308344
Using Colored Petri Nets for Conversation Modeling
Conversations are a useful means of structuring communicative interactions among agents. The value of a conversation-based approach is largely determined by the conversational model it uses. Finite State Machines, used heavily to date for this purpose, are not sufficient for complex agent interactions requiring a notion of concurrency. We propose the use of Colored Petri Nets as a model underlying a language for conversation specification. This carries the relative simplicity and graphical representation of the former approach, along with greater expressive power and support for concurrency. The construction of such a language, Protolingua, is currently being investigated within the framework of the Jackal agent development environment. In this paper, we explore the use of Colored Petri Nets in modeling agent communicative interaction.
18522080
Example of supersonic solutions to a steady state Euler-Poisson system
Abstract We give an example of supersonic solutions to a one-dimensional steady state Euler–Poisson system arising in the modeling of plasmas and semiconductors. The existence of the supersonic solutions which correspond to large current density is proved by Schauder’s fixed point theorem. We show also the uniqueness of solutions in the supersonic region.
16963632
Agents Making Sense of the Semantic Web
Effective use of the vast quantity of available information and services on the Internet will require multi-agent systems to be tightly integrated with existing web infrastructure. This however will be impossible unless the information on the web is presented in a semantic language, such as the DARPA Agent Markup Language (DAML), which is one aim of the “Semantic Web”. As part of our exploration of Semantic Web technology, and DAML in particular, we have constructed ITTALKS, a web-based system for automatic and intelligent notification of information technology talks. In this paper, we describe the ITTALKS system, and discuss the numerous ways in which the use of Semantic Web concepts and DAML extend its ability to provide an intelligent online service to both the human community and, more interestingly, the agents assisting them.
14722098
TCS-Chord: An Improved Routing Algorithm to Chord Based on the Topology-aware Clustering in Self-organizing Mode
The study on semantic routing efficiency of DHTP2P networks is a key element to promote the development of P2P networks, it is critical for a P2P routing algorithm to be aware of the network physical topology, which leads to improvement of the routing efficiency. By analyzing the Hashing function's properties, some novel logical connections are presented among the destination node, the Chord semantic routing relay node sequence, and the ID of clustering neighbor nodes. This paper describes TCS-Chord (an improved routing algorithm to Chord based on the Topology-aware Clustering in Self-organizing mode) to improve the efficiency of Chord routing. Since the clustering nodes only have local views in the self-organizing mode, some rules are applied for a node to learn other nodes' physical topology-aware locations. The TCS-Chord's routing algorithm is described completely, and our experiments also indicate that TCS-Chord can improve the Chord semantic routing efficiently.