Spectral graph theory. Regional conference series (1997)

by F Chung
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Semi-Supervised Learning Literature Survey

by Xiaojin Zhu , 2006
"... We review the literature on semi-supervised learning, which is an area in machine learning and more generally, artificial intelligence. There has been a whole spectrum of interesting ideas on how to learn from both labeled and unlabeled data, i.e. semi-supervised learning. This document is a chapter ..."
Abstract - Cited by 757 (8 self) - Add to MetaCart
We review the literature on semi-supervised learning, which is an area in machine learning and more generally, artificial intelligence. There has been a whole spectrum of interesting ideas on how to learn from both labeled and unlabeled data, i.e. semi-supervised learning. This document is a chapter excerpt from the author’s doctoral thesis (Zhu, 2005). However the author plans to update the online version frequently to incorporate the latest development in the field. Please obtain the latest version at http://www.cs.wisc.edu/~jerryzhu/pub/ssl_survey.pdf

Distributed communication algorithms for ad hoc mobile networks

by Ioannis Chatzigiannakis, Sotiris Nikoletseas, Paul Spirakis - Journal of Parallel and Distributed Computing (JPDC , 2003
"... An ad-hoc mobile network is a collection of mobile hosts, with wireless communication capabilities, forming a temporary network without the aid of any established fixed infrastructure. In such networks, topological connectivity is subject to frequent, unpredictable change. Our work focuses on networ ..."
Abstract - Cited by 15 (10 self) - Add to MetaCart
An ad-hoc mobile network is a collection of mobile hosts, with wireless communication capabilities, forming a temporary network without the aid of any established fixed infrastructure. In such networks, topological connectivity is subject to frequent, unpredictable change. Our work focuses on networks with high rate of such changes to connectivity. For such dynamically changing networks we propose protocols which exploit the co-ordinated (by the protocol) motion of a small part of the network. We show that such protocols can be designed to work correctly and efficiently even in the case of arbitrary (but not malicious) movements of the hosts not affected by the protocol. We also propose a methodology for the analysis of the expected behavior of protocols for such networks, based on the assumption that mobile hosts (those whose motion is not guided by the protocol) conduct concurrent random walks in their motion space. In particular, our work examines the fundamental problem of communication and proposes distributed algorithms for it. We provide rigorous proofs of their correctness, and also give performance analyses by combinatorial tools. Finally, we have evaluated these protocols by experimental means. 1
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Clustering and Searching WWW Images using Link and Page Layout Analysis

by Xiaofei He, Deng Cai, Ji-rong Wen, Wei-ying Ma, Hong-jiang Zhang - ACM Trans. Multimedia Comput. Commun. Appl
"... Due to the rapid growth of the number of digital images on the Web, there is an increasing demand for an effective and efficient method for organizing and retrieving the available images. This article describes iFind, a system for clustering and searching WWW images. By using a vision-based page seg ..."
Abstract - Cited by 14 (2 self) - Add to MetaCart
Due to the rapid growth of the number of digital images on the Web, there is an increasing demand for an effective and efficient method for organizing and retrieving the available images. This article describes iFind, a system for clustering and searching WWW images. By using a vision-based page segmentation algorithm, a Web page is partitioned into blocks, and the textual and link information of an image can be accurately extracted from the block containing that image. The textual information is used for image indexing. By extracting the page-to-block, block-to-image, block-to-page relationships through link structure and page layout analysis, we construct an image graph. Our method is less sensitive to noisy links than previous methods like PageRank, HITS, and PicASHOW, and hence the image graph can better reflect the semantic relationship between images. Using the notion of Markov Chain, we can compute the limiting probability distributions of the images, ImageRanks, which characterize the importance of the images. The ImageRanks are combined with the relevance scores to produce the final ranking for image search. With the graph models, we can also use techniques from spectral graph theory for image clustering and embedding, or
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Organizing WWW Images Based on The Analysis of Page Layout and Web Link Structure

by Deng Cai, Xiaofei He, Wei-ying Ma, Ji-rong Wen, Hongjiang Zhang - in The 2004 IEEE International Conference on Multimedia and EXPO , 2004
"... Due to the rapid growth of the number of digital images on the Web, there is an increasing demand for effective and efficient method for organizing and retrieving the images available. This paper describes a method for clustering and embedding WWW images. By using a vision-based page segmentation al ..."
Abstract - Cited by 12 (6 self) - Add to MetaCart
Due to the rapid growth of the number of digital images on the Web, there is an increasing demand for effective and efficient method for organizing and retrieving the images available. This paper describes a method for clustering and embedding WWW images. By using a vision-based page segmentation algorithm, a web page is partitioned into blocks, and the textual and link information of an image can be accurately extracted from the block containing that image. By extracting the page-to-block, block-toimage, block-to-page relationships through link structure and page layout analysis, we construct an image graph. With the image graph model, we use techniques from spectral graph theory for image clustering and embedding. Some experimental results are given in the paper. 1.
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Design and analysis of an efficient communication strategy for hierarchical and highly changing ad-hoc mobile networks

by Ioannis Chatzigiannakis, Sotiris Nikoletseas - In ACM/Baltzer Mobile Networks Journal (MONET), Special Issue on Parallel Processing Issues in Mobile Computing, Guest Editors: A. Zomaya , 2004
"... In this work we introduce two practical and interesting models of ad-hoc mobile networks: a) hierarchical ad-hoc networks, comprised of dense subnetworks of mobile users interconnected by a very fast yet limited backbone infrastructure, b) highly changing ad-hoc networks, where the deployment area c ..."
Abstract - Cited by 12 (5 self) - Add to MetaCart
In this work we introduce two practical and interesting models of ad-hoc mobile networks: a) hierarchical ad-hoc networks, comprised of dense subnetworks of mobile users interconnected by a very fast yet limited backbone infrastructure, b) highly changing ad-hoc networks, where the deployment area changes in a highly dynamic way and is unknown to the protocol. In such networks, we study the problem of basic communication, i.e. sending messages from a sender node to a receiver node. For highly changing networks, we investigate an efficient communication protocol exploiting the coordinated motion of a small part of an ad-hoc mobile network (the “runners support”) to achieve fast communication. This protocol instead of using a fixed sized support for the whole duration of the protocol, employs a support of some initial (small) size which adapts (given some time which can be made fast enough) to the actual levels of traffic and the (unknown and possibly rapidly changing) network area, by changing its size in order to converge to an optimal size, thus satisfying certain Quality of Service criteria. Using random walks theory, we show that such an adaptive approach is, for this class of ad-hoc mobile networks, significantly more efficient than a simple non-adaptive implementation of the basic “runners

The problem of deficiency indices for discrete Schrödinger operators on locally finite graphs

by Christoph Schumacher - J. Math. Phys
"... ar ..."
Abstract - Cited by 12 (2 self) - Add to MetaCart
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Pervasive computing management: A model of network policy with local autonomy

by Mark Burgess, Siri Fagernes - IEEE Transactions on Software Engineering , 2006
"... We present a model for policy based management, stressing the role of decisive autonomy in generalized networks. The organization and consistency of agent cooperation is discussed within a cooperative network. We show that some simple rules can eliminate formal inconsistencies, allowing robust appro ..."
Abstract - Cited by 11 (9 self) - Add to MetaCart
We present a model for policy based management, stressing the role of decisive autonomy in generalized networks. The organization and consistency of agent cooperation is discussed within a cooperative network. We show that some simple rules can eliminate formal inconsistencies, allowing robust approximations to management. Using graph theoretical ranking methods, we evaluate also the probable consistency and robustness of cooperation in a network region. Our theory makes natural contact with social network models in building a theory of pervasive computing. We illustrate our model with a number of examples. Index Terms Configuration management, ad hoc networks, peer to peer, pervasive computing. I.
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Graph-Based Semi-Supervised Learning as a Generative Model

by Jingrui He, Jaime Carbonell, Yan Liu
"... This paper proposes and develops a new graph-based semi-supervised learning method. Different from previous graph-based methods that are based on discriminative models, our method is essentially a generative model in that the class conditional probabilities are estimated by graph propagation and the ..."
Abstract - Cited by 10 (0 self) - Add to MetaCart
This paper proposes and develops a new graph-based semi-supervised learning method. Different from previous graph-based methods that are based on discriminative models, our method is essentially a generative model in that the class conditional probabilities are estimated by graph propagation and the class priors are estimated by linear regression. Experimental results on various datasets show that the proposed method is superior to existing graph-based semi-supervised learning methods, especially when the labeled subset alone proves insufficient to estimate meaningful class priors. 1

A RELATION BETWEEN THE MULTIPLICITY OF THE SECOND EIGENVALUE OF A GRAPH LAPLACIAN, COURANT’S NODAL LINE THEOREM AND THE SUBSTANTIAL DIMENSION OF TIGHT POLYHEDRAL SURFACES

by Tsvi Tlusty , 2007
"... A relation between the multiplicity m of the second eigenvalue λ2 of a Laplacian on agraphG, tight mappings of G and a discrete analogue of Courant’s nodal line theorem is discussed. For a certain class of graphs, it is shown that the m-dimensional eigenspace of λ2 is tight and thus defines a tight ..."
Abstract - Cited by 8 (0 self) - Add to MetaCart
A relation between the multiplicity m of the second eigenvalue λ2 of a Laplacian on agraphG, tight mappings of G and a discrete analogue of Courant’s nodal line theorem is discussed. For a certain class of graphs, it is shown that the m-dimensional eigenspace of λ2 is tight and thus defines a tight mapping of G into an m-dimensional Euclidean space. The tightness of the mapping is shown to set Colin de Verdiére’s upper bound on the maximal λ2-multiplicity, m ≤ chr(γ(G)) − 1, where chr(γ(G)) is the chromatic number and γ(G) is the genus of G.

LINE DIGRAPHS AND COINED QUANTUM RANDOM WALKS

by Simone Severini , 2002
"... Abstract. In this note, we give a characterization of the adjacency matrix of the line digraph of a regular digraph and we discuss a generalization.On the light of the characterization given, we remark that the underlying digraph of a coined quantum random walk is the line digraph of a regular digra ..."
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Abstract. In this note, we give a characterization of the adjacency matrix of the line digraph of a regular digraph and we discuss a generalization.On the light of the characterization given, we remark that the underlying digraph of a coined quantum random walk is the line digraph of a regular digraph. 1. A characterization of the adjacency matrix of the line digraph of a regular digraph 1.1. Set-up. The notion of line digraph has been introduced by Harary and Norman [HN60] in 1960. A classic survey on line graphs and digraphs is [HB78]; a recent one is [P95]. Line digraphs are used in the design and analysis of interconnection networks (see e.g. [FYA84]). Line digraphs are also used in algorithms for DIRECTED MAX-CUT [CE90] and TRAVELLING SALESMAN [GKWS98]. Definition 1 (Line digraph). The line digraph − → LD of a digraph ( D = (V, A) is the
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