Results 1 - 10 of 393,483

N: Meta-analysis in clinical trials

by Rebecca Dersimonian, Nan Laird - Controlled Clinical Trials , 1986
"... ABSTRACT: This paper examines eight published reviews each reporting results from several related trials. Each review pools the results from the relevant trials in order to evaluate the efficacy of a certain treatment for a specified medical condition. These reviews lack consistent assessment of hom ..."
Abstract - Cited by 1303 (0 self) - Add to MetaCart
ABSTRACT: This paper examines eight published reviews each reporting results from several related trials. Each review pools the results from the relevant trials in order to evaluate the efficacy of a certain treatment for a specified medical condition. These reviews lack consistent assessment

A Threshold of ln n for Approximating Set Cover

by Uriel Feige - JOURNAL OF THE ACM , 1998
"... Given a collection F of subsets of S = f1; : : : ; ng, set cover is the problem of selecting as few as possible subsets from F such that their union covers S, and max k-cover is the problem of selecting k subsets from F such that their union has maximum cardinality. Both these problems are NP-har ..."
Abstract - Cited by 776 (5 self) - Add to MetaCart
-hard. We prove that (1 \Gamma o(1)) ln n is a threshold below which set cover cannot be approximated efficiently, unless NP has slightly superpolynomial time algorithms. This closes the gap (up to low order terms) between the ratio of approximation achievable by the greedy algorithm (which is (1 \Gamma

Class-Based n-gram Models of Natural Language

by Peter F. Brown, Peter V. deSouza, Robert L. Mercer, Vincent J. Della Pietra, Jenifer C. Lai - Computational Linguistics , 1992
"... We address the problem of predicting a word from previous words in a sample of text. In particular we discuss n-gram models based on calsses of words. We also discuss several statistical algoirthms for assigning words to classes based on the frequency of their co-occurrence with other words. We find ..."
Abstract - Cited by 986 (5 self) - Add to MetaCart
We address the problem of predicting a word from previous words in a sample of text. In particular we discuss n-gram models based on calsses of words. We also discuss several statistical algoirthms for assigning words to classes based on the frequency of their co-occurrence with other words. We

The large N limit of superconformal field theories and supergravity

by Juan Maldacena , 1998
"... We show that the large N limit of certain conformal field theories in various dimensions include in their Hilbert space a sector describing supergravity on the product of AntideSitter spacetimes, spheres and other compact manifolds. This is shown by taking some branes in the full M/string theory and ..."
Abstract - Cited by 5631 (20 self) - Add to MetaCart
We show that the large N limit of certain conformal field theories in various dimensions include in their Hilbert space a sector describing supergravity on the product of AntideSitter spacetimes, spheres and other compact manifolds. This is shown by taking some branes in the full M/string theory

N Degrees of Separation: Multi-Dimensional Separation of Concerns

by Peri Tarr, Harold Ossher, William Harrison, Stanley M. Sutton, Jr. - IN PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON SOFTWARE ENGINEERING , 1999
"... Done well, separation of concerns can provide many software engineering benefits, including reduced complexity, improved reusability, and simpler evolution. The choice of boundaries for separate concerns depends on both requirements on the system and on the kind(s) of decompositionand composition a ..."
Abstract - Cited by 522 (8 self) - Add to MetaCart
Done well, separation of concerns can provide many software engineering benefits, including reduced complexity, improved reusability, and simpler evolution. The choice of boundaries for separate concerns depends on both requirements on the system and on the kind(s) of decompositionand composition a

AN n 5/2 ALGORITHM FOR MAXIMUM MATCHINGS IN BIPARTITE GRAPHS

by John E. Hopcroft, Richard M. Karp , 1973
"... The present paper shows how to construct a maximum matching in a bipartite graph with n vertices and m edges in a number of computation steps proportional to (m + n)x/. ..."
Abstract - Cited by 702 (1 self) - Add to MetaCart
The present paper shows how to construct a maximum matching in a bipartite graph with n vertices and m edges in a number of computation steps proportional to (m + n)x/.

The Dantzig selector: statistical estimation when p is much larger than n

by Emmanuel Candes, Terence Tao , 2005
"... In many important statistical applications, the number of variables or parameters p is much larger than the number of observations n. Suppose then that we have observations y = Ax + z, where x ∈ R p is a parameter vector of interest, A is a data matrix with possibly far fewer rows than columns, n ≪ ..."
Abstract - Cited by 879 (14 self) - Add to MetaCart
In many important statistical applications, the number of variables or parameters p is much larger than the number of observations n. Suppose then that we have observations y = Ax + z, where x ∈ R p is a parameter vector of interest, A is a data matrix with possibly far fewer rows than columns, n

Coarse-to-fine n-best parsing and MaxEnt discriminative reranking

by Eugene Charniak, Mark Johnson - In ACL , 2005
"... Discriminative reranking is one method for constructing high-performance statistical parsers (Collins, 2000). A discriminative reranker requires a source of candidate parses for each sentence. This paper describes a simple yet novel method for constructing sets of 50-best parses based on a co ..."
Abstract - Cited by 522 (15 self) - Add to MetaCart
Discriminative reranking is one method for constructing high-performance statistical parsers (Collins, 2000). A discriminative reranker requires a source of candidate parses for each sentence. This paper describes a simple yet novel method for constructing sets of 50-best parses based on a

A Faster Algorithm for Betweenness Centrality

by Ulrik Brandes - Journal of Mathematical Sociology , 2001
"... The betweenness centrality index is essential in the analysis of social networks, but costly to compute. Currently, the fastest known algorithms require #(n ) time and #(n ) space, where n is the number of actors in the network. ..."
Abstract - Cited by 554 (5 self) - Add to MetaCart
The betweenness centrality index is essential in the analysis of social networks, but costly to compute. Currently, the fastest known algorithms require #(n ) time and #(n ) space, where n is the number of actors in the network.

Numerical integration of the Cartesian equations of motion of a system with constraints: molecular dynamics of n-alkanes

by Jean-paul Ryckaert, Giovanni Ciccotti, Herman J. C. Berendsen - J. Comput. Phys , 1977
"... A numerical algorithm integrating the 3N Cartesian equations of motion of a system of N points subject to holonomic constraints is formulated. The relations of constraint remain perfectly fulfilled at each step of the trajectory despite the approximate character of numerical integration. The method ..."
Abstract - Cited by 704 (6 self) - Add to MetaCart
A numerical algorithm integrating the 3N Cartesian equations of motion of a system of N points subject to holonomic constraints is formulated. The relations of constraint remain perfectly fulfilled at each step of the trajectory despite the approximate character of numerical integration. The method
Results 1 - 10 of 393,483