30442545
On Kotzig's conjecture concerning graphs with a unique regular path-connectivity
Abstract Kotzig (see Bondy and Murty, Graph Theory with Applications, North-Holland, Amsterdam, 1976) conjectured that there exists no graph with the property that every pair of vertices is connected by a unique path of length k, k>2 . Kotzig (Graph Theory and Related Topics, Academic Press, New York, 1979, pp. 358–367) has proved this conjecture for 2 . Xing and Hu (Discrete Math. 135 (1994) 387–393) have proved it for k>11 . Here we prove this conjecture for the remaining cases k=9,10,11 .
7877505
Three forbidden subgraphs for line graphs
We construct a set of three graphs with the property that a 3-connected graph with minimum degree at least 7 is a line graph if and only if it does not contain any of the three graphs as an induced subgraph. We also show that the number of excluded subgraphs cannot be reduced no matter what connectivity is specified.
205877442
On distinct distance sets in a graph
A distinct distance set (DD set) for a graph G is a vertex subset of G with the property that for vbSvb = s, we have (2s) distinct distances of the pairs of vertices in S.In this article, it is shown that(a) For 6 ? k ? 18 there exists a tree T with DD(T) = k and dm(T) = LB(k) < B1(Kk), where LB(k) is the smallest value L for which there are positive integers A and B with A+B=k, A2+B2??L2?, AB??L2?.(b) For k ? 10, the minimum order of a tree T with DD(T) = k is B1(Kk), which is the order of the corresponding Colomb ruler for k.
10222228
The third Ramsey numbers for graphs with at most four edges
Abstract With the help of a computer, the Ramsey numbers r 3 ( H ) are obtained for each of the 19 graphs H with at most four edges and no isolated vertices.
12971843
Smooth Playout Control for Video Streaming over Error-Prone Channels
The quality of media streaming over best-effort networks suffers from network delays and packet losses. The latter is more profound for wireless video. To enhance the QoS of streaming services, adaptive media playout (AMP) has been developed to adjust the playout interval. With AMP, the risk of delay and buffer underflow is reduced. However, the smoothness of playback is not guaranteed. In this paper, we propose a novel AMP control that enables smooth playout and meanwhile maintains reliable visual quality. Our AMP control adjusts the playout interval based on an estimation of channel quality, so it is more adaptive than conventional AMP controls that are based on buffer fullness. Experimental results are provided to justify our approach. Even at 20% packet loss rate, the proposed AMP control is still able to provide smooth and reliable playback
1161111
Localization in sparse networks using sweeps
Determining node positions is essential for many next-generation network functionalities. Previous localization algorithms lack correctness guarantees or require network density higher than required for unique localizability. In this paper, we describe a class of algorithms for fine-grained localization called Sweeps. Sweeps correctly finitely localizes all nodes in bilateration networks. Sweeps also handles angle measurements and noisy measurements. We demonstrate the practicality of our algorithm through extensive simulations on a large number of networks, upon which it consistently localizes one-thousand-node networks of average degree less than five in less than two minutes on a consumer PC.
17384103
RDT Properties and Evaluations
Proposed for MPCs, RDT has already been proved to support better performances than most of the direct network, such as smaller diameter based on its vector routing algorithm, smaller degree, embedded mesh/torus topology, etc. It gives a network form method to form groups of networks with recursively structured torus/torus-like networks. A RDT structure can be formed with the method and its related parameters. After analyzing its performance by the average distance, the descending vector routing reducing redundant computations and the fault-tolerant routing algorithm are proposed. A simpler structure named RDT(2,2,1)/a are proposed for the parallel systems with no more than 5000 nodes and given its performance evaluation. Considering the structure features of the practical RDTs, they are suitable for the interconnection network of an NoC design. The design of laying out RDT(2,2, 1)/a is proposed and proved to be available
1759932
Main business service dimensions in an e-commerce environment
Improving service quality has long been recognized as a key business strategy in consumer market. However, little is written in the literature about service among business organizations. The shortage of knowledge on business service (BS) poses a significant challenge in tracking and improving BS quality in today's e-commerce environment. To address this, this paper takes a first step to identify main BS dimensions in an e-commerce environment. It first provides a review on BS. Then the BS gap model and main BS dimension are identified. The paper concludes with a summary and future research suggestions.
2911118
A Theory of Network Localization
In this paper, we provide a theoretical foundation for the problem of network localization in which some nodes know their locations and other nodes determine their locations by measuring the distances to their neighbors. We construct grounded graphs to model network localization and apply graph rigidity theory to test the conditions for unique localizability and to construct uniquely localizable networks. We further study the computational complexity of network localization and investigate a subclass of grounded graphs where localization can be computed efficiently. We conclude with a discussion of localization in sensor networks where the sensors are placed randomly