35455221
A characterization of pancyclic complements of line graphs
Abstract We characterize graphs G such that the complements of their line graphs are pancyclic.
10016971
Improved bottleneck domination algorithms
W.C.K. Yen introduced BOTTLENECK DOMINATION and BOTTLENECK INDEPENDENT DOMINATION. He presented an O(n log n + m)- time algorithm to compute a minimum bottleneck dominating set. He also obtained that the BOTTLENECK INDEPENDENT DOMINATING SET problem is NP-complete, even when restricted to planar graphs.We present simple linear time algorithms for the BOTTLENECK DOMINATING SET and the BOTTLENECK TOTAL DOMINATING SET problem. Furthermore, we give polynomial time algorithms (most of them with linear time-complexities) for the BOTTLENECK INDEPENDENT DOMINATING SET problem on the following graph classes: AT-free graphs, chordal graphs, split graphs, permutation graphs, graphs of bounded treewidth, and graphs of clique-width at most k with a given k-expression.
195860670
Optimal stream replication for video simulcasting
Video simulcasting enables a sender to generate multiple streams for the same video program but at different rates, targeting receivers of different capacities. Each stream can then be distributed to the target receivers via broadcast or multicast channels. One of the critical issues in video simulcasting is to strike a balance between bandwidth consumption and the user satisfaction. This is because stream replication introduces redundancy which can potentially lead to excessive use of the bandwidth, while on the other hand there usually is a mismatch between a receiver's capacity and the limited choice of the stream bandwidths. We present a formal study on the above issue, which we refer as the optimal stream replication problem. We first formulate the optimal replication problem for a given session bandwidth budget and number of streams, with the objective of minimizing the expected mismatch for all the receivers in the session. A proper choice for the number of the replicated streams is critical in the overall bandwidth provisioning. Though it has been largely assumed that the number of streams is predetermined by service providers, we find that dynamic adjustment of stream number is possible in advanced video stream systems, such as the MPEG-4 Delivery Multimedia Integration Framework (DIMF), and systems employing fast video transcoding algorithms. Therefore, we also study the case of a flexible stream number, with the objective of jointly optimize the stream number and bandwidth allocated to each stream.
18277516
Mesh Optimisation Using Edge Information in Feature-Based Surface Reconstruction
One of the most challenging and fundamental problems in computer vision is to reconstruct a surface model given a set of uncalibrated 2D images. Well-established Structure from Motion (SfM) algorithms often result in a sparse set of 3D surface points, but surface modelling based on sparse 3D points is not easy. In this paper, we present a new method to refine and optimise surface meshes using edge information in the 2D images. We design a meshing – edge point detection – re-meshing scheme that can gradually refine the surface mesh until it best fits the true physical surface of the object being modelled. Our method is tested on real images and satisfactory results are obtained.
36178651
The vertex linear arboricity of distance graphs
A distance graph is a graph G(R,D) with the set of all points of the real line as vertex set and two vertices u,[email protected]?R are adjacent if and only if |u-v|@?D where the distance set D is a subset of the positive real numbers. Here, the vertex linear arboricity of G(R,D) is determined when D is an interval between 1 and @d. In particular, the vertex linear arboricity of integer distance graphs G(D) is discussed, too.
215341
Experimental results on user knowledge assessment with an evidential reasoning methodology
User modeling is a crucial element of intelligent interfaces. This paper presents some preliminary resultson a method for the assessment of user knowledge. Knowledge of an individual is modeled as a subset of a global set of knowledge units (KU). The KUS are interrelated among each other through implication relations, indicating that certain KUS are prerequisite to others. The structure of implications is induced algorithmically through an induction procedure utilizing empirical data on the knowledge state of a number of subjects. It is thereafter used in a knowledge assessment process based on the Dempster-Shafer evidential reasoning methodology. The preliminary results demonstrate that our approach can successfully assess knowledge by randomly sampling KUS in a knowledge state and infer which KUS are known and unknown.
30478531
Hamiltonian decompositions of Cayley graphs on Abelian groups
Abstract Alspach has conjectured that any 2k-regular connected Cayley graph cay(A,S) on a finite abelian group A can be decomposed into k hamiltonian cycles. In this paper, the conjecture is shown to be true if S={s1,s2,s3} is a minimal generating set of A with |A| odd, or S={s1,s2,…,sk} is a generating set of A such that gcd(ord(si),ord(sj))= 1 for i≠j.