Results 1 - 10 of 13,756

Finding community structure in networks using the eigenvectors of matrices

by M. E. J. Newman , 2006
"... We consider the problem of detecting communities or modules in networks, groups of vertices with a higher-than-average density of edges connecting them. Previous work indicates that a robust approach to this problem is the maximization of the benefit function known as “modularity ” over possible div ..."
Abstract - Cited by 502 (0 self) - Add to MetaCart
divisions of a network. Here we show that this maximization process can be written in terms of the eigenspectrum of a matrix we call the modularity matrix, which plays a role in community detection similar to that played by the graph Laplacian in graph partitioning calculations. This result leads us to a

Magnetism from conductors and enhanced nonlinear phenomena,”

by . J B Pendry , A J Holden , D J Robbins , W J Stewart - IEEE Trans. on Microwave Theory and Techniques, , 1999
"... Abstract: We analyze the transmission properties of double negative metamaterials (DNM). Numerical simulations, based on the transfer matrix algorithm, show that some portion of the electromagnetic wave changes its polarization inside the DNM structure. As the transmission properties depend strongl ..."
Abstract - Cited by 465 (3 self) - Add to MetaCart
Abstract: We analyze the transmission properties of double negative metamaterials (DNM). Numerical simulations, based on the transfer matrix algorithm, show that some portion of the electromagnetic wave changes its polarization inside the DNM structure. As the transmission properties depend

Handling Churn in a DHT

by Sean Rhea, Dennis Geels, Timothy Roscoe, John Kubiatowicz - In Proceedings of the USENIX Annual Technical Conference , 2004
"... This paper addresses the problem of churn---the continuous process of node arrival and departure---in distributed hash tables (DHTs). We argue that DHTs should perform lookups quickly and consistently under churn rates at least as high as those observed in deployed P2P systems such as Kazaa. We then ..."
Abstract - Cited by 450 (22 self) - Add to MetaCart
then show through experiments on an emulated network that current DHT implementations cannot handle such churn rates. Next, we identify and explore three factors affecting DHT performance under churn: reactive versus periodic failure recovery, message timeout calculation, and proximity neighbor selection

A rapid hierarchical radiosity algorithm

by Pat Hanrahan, David Salzman - Computer Graphics , 1991
"... This paper presents a rapid hierarchical radiosity algorithm for illuminating scenes containing lar e polygonal patches. The afgorithm constructs a hierarchic“J representation of the form factor matrix by adaptively subdividing patches into su bpatches according to a user-supplied error bound. The a ..."
Abstract - Cited by 409 (11 self) - Add to MetaCart
. The algorithm guarantees that all form factors are calculated to the same precision, removing many common image artifacts due to inaccurate form factors. More importantly, the al o-rithm decomposes the form factor matrix into at most O? n) blocks (where n is the number of elements). Previous radiosity

Segmentation using eigenvectors: A unifying view

by Yair Weiss - In ICCV , 1999
"... Automatic grouping and segmentation of images remains a challenging problem in computer vision. Recently, a number of authors have demonstrated good performance on this task using methods that are based on eigenvectors of the a nity matrix. These approaches are extremely attractive in that they are ..."
Abstract - Cited by 380 (1 self) - Add to MetaCart
Automatic grouping and segmentation of images remains a challenging problem in computer vision. Recently, a number of authors have demonstrated good performance on this task using methods that are based on eigenvectors of the a nity matrix. These approaches are extremely attractive

A new method for non-parametric multivariate analysis of variance in ecology.

by Marti J Anderson - Austral Ecology, , 2001
"... Abstract Hypothesis-testing methods for multivariate data are needed to make rigorous probability statements about the effects of factors and their interactions in experiments. Analysis of variance is particularly powerful for the analysis of univariate data. The traditional multivariate analogues, ..."
Abstract - Cited by 368 (4 self) - Add to MetaCart
-parametric methods because it allows a direct additive partitioning of variation for complex models. It does this while maintaining the flexibility and lack of formal assumptions of other non-parametric methods. The teststatistic is a multivariate analogue to Fisher's F-ratio and is calculated directly from any

Partitioning of Unstructured Problems for Parallel Processing

by Horst D. Simon , 1991
"... Many large scale computational problems are based on unstructured computational domains. Primary examples are unstructured grid calculations based on finite volume methods in computational fluid dynamics, or structural analysis problems based on finite element approximations. Here we will address th ..."
Abstract - Cited by 344 (16 self) - Add to MetaCart
Many large scale computational problems are based on unstructured computational domains. Primary examples are unstructured grid calculations based on finite volume methods in computational fluid dynamics, or structural analysis problems based on finite element approximations. Here we will address

Measuring Bottleneck Link Speed in Packet-Switched Networks

by Robert L. Carter, Mark E. Crovella - PERFORMANCE EVALUATION , 1996
"... The quality of available network connections can often have a large impact on the performance of distributed applications. For example, document transfer applications such as FTP, Gopher and the World Wide Web suffer increased response times as a result of network congestion. For these applications, ..."
Abstract - Cited by 333 (10 self) - Add to MetaCart
, the document transfer time is directly related to the available bandwidth of the connection. Available bandwidth depends on two things: 1) the underlying capacity of the path from client to server, which is limited by the bottleneck link; and 2) the amount of other traffic competing for links on the path

Conflict Resolution for Air Traffic Management: A Study in Multiagent Hybrid Systems

by Claire Tomlin, George J. Pappas, Shankar Sastry - IEEE TRANSACTIONS ON AUTOMATIC CONTROL , 1998
"... Air Traffic Management (ATM) of the future allows for the possibility of free flight, in which aircraft choose their own optimal routes, altitudes, and velocities. The safe resolution of trajectory conflicts between aircraft is necessary to the success of such a distributed control system. In this p ..."
Abstract - Cited by 287 (50 self) - Add to MetaCart
Air Traffic Management (ATM) of the future allows for the possibility of free flight, in which aircraft choose their own optimal routes, altitudes, and velocities. The safe resolution of trajectory conflicts between aircraft is necessary to the success of such a distributed control system

A Markov-modulated characterization of packetized voice and data traffic and related statistical multiplexer performance

by Harry Heffes, et al. - IEEE J. ON SELECTED AREAS IN COMMUN , 1986
"... We study the performance of a statistical multiplexer whose inputs consist of a superposition of packetized voice sources and data. The performance analysis predicts voice packet delay distributions, which usually have a stringent requirement, as well as data packet delay distributions. The superpos ..."
Abstract - Cited by 288 (4 self) - Add to MetaCart
. The superposition is approximated by a correlated Markov modulated Poisson process (MMPP), which is chosen such that several of its statistical characteristics identically match those of the superposition. Matrix analytic methods are then used to evaluate system performance measures. In particular, we obtain
Results 1 - 10 of 13,756