Results 1 - 10 of 579

Poly-logarithmic deterministic fully-dynamic graph algorithms I: connectivity and minimum spanning tree

by Jacob Holm, Kristian de Lichtenberg, Mikkel Thorup - JOURNAL OF THE ACM , 1997
"... Deterministic fully dynamic graph algorithms are presented for connectivity and minimum spanning forest. For connectivity, starting with no edges, the amortized cost for maintaining a spanning forest is O(log² n) per update, i.e. per edge insertion or deletion. Deciding connectivity between any two ..."
Abstract - Cited by 154 (7 self) - Add to MetaCart
given vertices is done in O(log n= log log n) time. This matches the previous best randomized bounds. The previous best deterministic bound was O( 3 p n log n) amortized time per update but constant time for connectivity queries. For minimum spanning trees, first a deletions-only algorithm

Answering queries using views

by Alon Y. Levy, Alberto O. Mendelzon, Yehoshua Sagiv, Divesh Srivastava - In PODS Conference , 1995
"... We consider the problem of computing answers to queries by using materialized views. Aside from its potential in optimizing query evaluation, the problem also arises in applications such as Global Information Systems, Mobile Computing and maintaining physical data independence. We consider the probl ..."
Abstract - Cited by 447 (32 self) - Add to MetaCart
of deciding which literals from the original query can be deleted). We describe a polynomial time algorithm for nding rewritings, and show that under certain conditions, it will nd the minimal rewriting. Finally, we analyze the complexity of the problems when the queries and views may be disjunctive

The development and comparison of robust methods for estimating the fundamental matrix

by P. H. S. Torr, D. W. Murray - International Journal of Computer Vision , 1997
"... Abstract. This paper has two goals. The first is to develop a variety of robust methods for the computation of the Fundamental Matrix, the calibration-free representation of camera motion. The methods are drawn from the principal categories of robust estimators, viz. case deletion diagnostics, M-est ..."
Abstract - Cited by 266 (10 self) - Add to MetaCart
of the parameters are examined. The results of the comparison have broad applicability to vision algorithms where the input data are corrupted not only by noise but also by gross outliers.

The TPR*-Tree: An Optimized Spatio-Temporal Access Method for Predictive Queries

by Yufei Tao, Dimitris Papadias, Jimeng Sun - In VLDB , 2003
"... A predictive spatio-temporal query retrieves the set of moving objects that will intersect a query window during a future time interval. Currently, the only access method for processing such queries in practice is the TPR-tree. In this paper we first perform an analysis to determine the factor ..."
Abstract - Cited by 191 (10 self) - Add to MetaCart
the factors that affect the performance of predictive queries and show that several of these factors are not considered by the TPR-tree, which uses the insertion/deletion algorithms of the R*-tree designed for static data. Motivated by this, we propose a new index structure called the TPR*- tree, which

Incremental Clustering for Mining in a Data Warehousing Environment

by Martin Ester, Hans-Peter Kriegel, Jörg Sander, Michael Wimmer, Xiaowei Xu - PROC. 24TH INT. CONF. VERY LARGE DATA BASES, VLDB , 1998
"... Data warehouses provide a great deal of opportunities for performing data mining tasks such as classification and clustering. Typically, updates are collected and applied to the data warehouse periodically in a batch mode, e.g., during the night. Then, all patterns derived from the warehouse by some ..."
Abstract - Cited by 138 (8 self) - Add to MetaCart
is applicable to any database containing data from a metric space, e.g., to a spatial database or to a WWW-log database. Due to the density-based nature of DBSCAN, the insertion or deletion of an object affects the current clustering only in the neighborhood of this object. Thus, efficient algorithms can

Sorting by transpositions

by Vineet Bafna, Pavel, A. Pevzner - SIAM Journal on Discrete Mathematics , 1998
"... Abstract. Sequence comparison in computational molecular biology is a powerful tool for deriving evolutionary and functional relationships between genes. However, classical alignment algorithms handle only local mutations (i.e., insertions, deletions, and substitutions of nucleotides) and ignore glo ..."
Abstract - Cited by 140 (5 self) - Add to MetaCart
Abstract. Sequence comparison in computational molecular biology is a powerful tool for deriving evolutionary and functional relationships between genes. However, classical alignment algorithms handle only local mutations (i.e., insertions, deletions, and substitutions of nucleotides) and ignore

A General Incremental Technique for Maintaining Discovered Association Rules

by David W. Cheung, S. D. Lee, Benjamin Kao - In Proceedings of the Fifth International Conference On Database Systems For Advanced Applications , 1997
"... A more general incremental updating technique is developed for maintaining the association rules discovered in a database in the cases including insertion, deletion, and modification of transactions in the database. A previously proposed algorithm FUP can only handle the maintenance problem in the c ..."
Abstract - Cited by 110 (5 self) - Add to MetaCart
A more general incremental updating technique is developed for maintaining the association rules discovered in a database in the cases including insertion, deletion, and modification of transactions in the database. A previously proposed algorithm FUP can only handle the maintenance problem

Tracking join and self-join sizes in limited storage

by Noga Alon, Phillip B. Gibbons, Yossi Matias, Mario Szegedy , 2002
"... This paper presents algorithms for tracking (approximate) join and self-join sizes in limited storage, in the presence of insertions and deletions to the data set(s). Such algorithms detect changes in join and self-join sizes without an expensive recomputation from the base data, and without the lar ..."
Abstract - Cited by 123 (0 self) - Add to MetaCart
This paper presents algorithms for tracking (approximate) join and self-join sizes in limited storage, in the presence of insertions and deletions to the data set(s). Such algorithms detect changes in join and self-join sizes without an expensive recomputation from the base data, and without

An Efficient Algorithm for the Incremental Updation of Association Rules in Large Databases

by Shiby Thomas, Sreenath Bodagala, Khaled Alsabti, Sanjay Ranka , 1997
"... Efficient discovery of association rules in large databases is a well studied problem and several approaches have been proposed. However, it is non trivial to maintain the association rules current when the database is updated since, such updates could invalidate existing rules or introduce new rule ..."
Abstract - Cited by 86 (1 self) - Add to MetaCart
rules. In this paper, we propose an incremental updating technique based on negative borders, for the maintenance of association rules when new transaction data is added to or deleted from a transaction database. An important feature of our algorithm is that it requires a full scan(exactly one

Load balancing in dynamic structured p2p systems

by Brighten Godfrey, Karthik Lakshminarayanan, Sonesh Surana, Richard Karp, Ion Stoica - in Proc. IEEE INFOCOM , 2003
"... Abstract — Most P2P systems that provide a DHT abstraction distribute objects randomly among “peer nodes ” in a way that results in some nodes having times as many objects as the average node. Further imbalance may result due to nonuniform distribution of objects in the identifier space and a high d ..."
Abstract - Cited by 110 (1 self) - Add to MetaCart
, we propose an algorithm for load balancing in such heterogeneous, dynamic P2P systems. Our simulation results show that in the face of rapid arrivals and departures of objects of widely varying load, our algorithm achieves load balancing for system utilizations as high as 90 % while moving only about
Results 1 - 10 of 579