4324450
Cycles through subsets with large degree sums
Let G be a 2-connected graph on n vertices and let X V(G). We say that G is X-cyclable if G has an X-cycle, i.e., a cycle containing all vertices of X. We denote by ?(X) the maximum number of pairwise nonadjacent vertices in the subgraph G[X] of G induced by X. If G[X] is not complete, we denote by ?(X) the minimum cardinality of a set of vertices of G separating two vertices of X. By ?(X) we denote the minimum degree (in G) of the vertices of X, and by ?3(X) the minimum value of the degree sum (in G) of any three pairwise nonadjacent vertices of X. Our first main result is the following extension in terms of X-cyclability of a result on hamiltonian graphs by Bauer et al. If ?3(X) n + mingk(X), ?(X), then G is X-cyclable. Our second main result is the following generalization of a result of Fournier. If ?(X) ?(X), then G is X-cyclable. We give a number of extensions of other known results, thereby generalizing some recent results of Veldman.
5056715
Cycles Containing Given Subsets in 1-Tough Graphs
5901027
Cycles Containing Many Vertices of Subsets in 1-Tough Graphs with Large Degree Sums
262582
Schedule burst proactively for optical burst switched networks
Optical Burst Switching (OBS) is a promising paradigm for the next-generation Internet infrastructure. In OBS, a key problem is to schedule bursts on channels with both fast and bandwidth efficient algorithms so as to reduce burst loss. To date, most scheduling algorithms avoid burst contention locally (or reactively). In this paper, we propose several novel algorithms for scheduling bursts in OBS networks with and without wavelength conversion capability. The basic idea of our algorithms is to serialize the bursts on an outgoing link to reduce the number of bursts that may arrive at downstream nodes simultaneously (and thus pro-actively reduce the burst contention and burst loss probability at downstream nodes). This can be accomplished by judiciously delaying locally assembled bursts beyond a pre-determined offset time at an ingress node using the electronic memory. Compared with the existing algorithms, our proposed algorithms can significantly reduce the loss rate while ensuring that maximum delay of a burst does not exceed its prescribed limit.
24315827
On neighborhood condition for graphs to have [a, b]-factors
Let G be a graph of order n, and let a and b be integers such that 1 ≤ a > b. Let δ(G) be the minimum degree of G. Then we prove that if δ(G) ≥ (k - 1) a, n ≥ (a + b)(k(a + b) - 2)/b, and |NG(x1) ∪ NG(x2) ∪..∪ NG(xk)| ≥ an/(a + b) for any independent subset {x1,x2 ..... xk} of V(G), where k ≥ 2, then G has an [a,b]-factor. This result is best possible in some sense.
7021137
Machine annotation and retrieval for digital imagery of historical materials
Annotating digital imagery of historical materials for the purpose of computer-based retrieval is a labor-intensive task for many historians and digital collection managers. We have explored the possibilities of automated annotation and retrieval of images from collections of art and cultural images. In this paper, we introduce the application of the ALIP (Automatic Linguistic Indexing of Pictures) system, developed at Penn State, to the problem of machine-assisted annotation of images of historical materials. The ALIP system learns the expertise of a human annotator on the basis of a small collection of annotated representative images. The learned knowledge about the domain-specific concepts is stored as a dictionary of statistical models in a computer-based knowledge base. When an un-annotated image is presented to ALIP, the system computes the statistical likelihood of the image resembling each of the learned statistical models and the best concept is selected to annotate the image. Experimental results, obtained using the Emperor image collection of the Chinese Memory Net project, are reported and discussed. The system has been trained using subsets of images and metadata from the Emperor collection. Finally, we introduce an integration of wavelet-based annotation and wavelet-based progressive displaying of very high resolution copyright-protected images.
27085181
A new degree condition for graphs to have [a, b]-factor
Abstract Let t ( ⩾ 3 ) , a and b be integers with 0 ⩽ a b . A graph is called K 1 , t -free if it contains no K 1 , t as an induced subgraph. We prove that every K 1 , t -free G has an [ a , b ] -factor if its minimum degree is at least ( t - 1 ) ( a + 1 ) + b b b + a ( t - 1 ) 2 ( t - 1 ) - t - 1 b b + a ( t - 1 ) 2 ( t - 1 ) 2 - 1 . This degree condition is sharp.
11869668
Joint image compression and classification with vector quantization and a two dimensional hidden Markov model
We present an algorithm to achieve good compression and classification for images using vector quantization and a two dimensional hidden Markov model. The feature vectors of image blocks are assumed to be generated by a two dimensional hidden Markov model. We first estimate the parameters of the model, then design a vector quantizer to minimize a weighted sum of compression distortion and classification risk, the latter being defined as the negative of the maximum log likelihood of states and feature vectors. The algorithm is tested on both synthetic data and real image data. The extension to joint progressive compression and classification is discussed.