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Some methods for classification and analysis of multivariate observations

by J. Macqueen - In 5-th Berkeley Symposium on Mathematical Statistics and Probability , 1967
"... The main purpose of this paper is to describe a process for partitioning an N-dimensional population into k sets on the basis of a sample. The process, which is called 'k-means, ' appears to give partitions which are reasonably ..."
Abstract - Cited by 3055 (3 self) - Add to MetaCart
The main purpose of this paper is to describe a process for partitioning an N-dimensional population into k sets on the basis of a sample. The process, which is called 'k-means, ' appears to give partitions which are reasonably

Selection on Observed and Unobserved Variables: Assessing the Effectiveness of Catholic Schools

by Joseph G. Altonji, Todd E. Elder, Christopher R. Taber , 2002
"... In this paper we measure the effect of Catholic high school attendance on educational attainment and test scores. Because we do not have a good instrumental variable for Catholic school attendance, we develop new estimation methods based on the idea that the amount of selection on the observed expla ..."
Abstract - Cited by 538 (14 self) - Add to MetaCart
In this paper we measure the effect of Catholic high school attendance on educational attainment and test scores. Because we do not have a good instrumental variable for Catholic school attendance, we develop new estimation methods based on the idea that the amount of selection on the observed

The Concerted Action’s main observations

by Donald Evans, Martyn Evans
"... Fertility, infertility and the human embryo: ethics, law and practice of human artificial procreation* ..."
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Fertility, infertility and the human embryo: ethics, law and practice of human artificial procreation*

Identification of programmed cell death in situ via specific labeling of nuclear DNA fragmentation

by Yael Gavrieli, Yoav Sherman, Shmuel A. Ben-sasson - J. Cell , 1992
"... Abstract. Programmed cell death (PCD) plays a key role in developmental biology and in maintenance of the steady state in continuously renewing tissues. Currently, its existence is inferred mainly from gel electrophoresis of a pooled DNA extract as PCD was shown to be associated with DNA fragmentati ..."
Abstract - Cited by 691 (0 self) - Add to MetaCart
Abstract. Programmed cell death (PCD) plays a key role in developmental biology and in maintenance of the steady state in continuously renewing tissues. Currently, its existence is inferred mainly from gel electrophoresis of a pooled DNA extract as PCD was shown to be associated with DNA

A Fast and Elitist Multi-Objective Genetic Algorithm: NSGA-II

by Kalyanmoy Deb, Amrit Pratap, Sameer Agarwal, T. Meyarivan , 2000
"... Multi-objective evolutionary algorithms which use non-dominated sorting and sharing have been mainly criticized for their (i) O(MN computational complexity (where M is the number of objectives and N is the population size), (ii) non-elitism approach, and (iii) the need for specifying a sharing param ..."
Abstract - Cited by 1815 (60 self) - Add to MetaCart
Multi-objective evolutionary algorithms which use non-dominated sorting and sharing have been mainly criticized for their (i) O(MN computational complexity (where M is the number of objectives and N is the population size), (ii) non-elitism approach, and (iii) the need for specifying a sharing

Least angle regression

by Bradley Efron, Trevor Hastie, Iain Johnstone, Robert Tibshirani , 2004
"... The purpose of model selection algorithms such as All Subsets, Forward Selection and Backward Elimination is to choose a linear model on the basis of the same set of data to which the model will be applied. Typically we have available a large collection of possible covariates from which we hope to s ..."
Abstract - Cited by 1326 (37 self) - Add to MetaCart
to select a parsimonious set for the efficient prediction of a response variable. Least Angle Regression (LARS), a new model selection algorithm, is a useful and less greedy version of traditional forward selection methods. Three main properties are derived: (1) A simple modification of the LARS algorithm

Climate and atmospheric history of the past 420,000 years from the Vostok ice core,

by J R Petit , J Jouzel , D Raynaud , N I Barkov , J.-M Barnola , I Basile , M Bender , J Chappellaz , M Davisk , G Delaygue , M Delmotte , V M Kotlyakov , M Legrand , V Y Lipenkov , C Lorius , L Pé , C Ritz , E Saltzmank , M Stievenard - Antarctica. Nature , 1999
"... Antarctica has allowed the extension of the ice record of atmospheric composition and climate to the past four glacial-interglacial cycles. The succession of changes through each climate cycle and termination was similar, and atmospheric and climate properties oscillated between stable bounds. Inte ..."
Abstract - Cited by 716 (15 self) - Add to MetaCart
glacial-interglacial cycles [4][5][6][7][8][9] Here we present a series of detailed Vostok records covering this ϳ400-kyr period. We show that the main features of the more recent Vostok climate cycle resemble those observed in earlier cycles. In particular, we confirm the strong correlation between

Brain magnetic resonance imaging with contrast dependent on blood oxygenation.

by S Ogawa , T M Lee , A R Kay , D W Tank - Proc. Natl. Acad. Sci. USA , 1990
"... ABSTRACT Paramagnetic deoxyhemoglobin in venous blood is a naturally occurring contrast agent for magnetic resonance imaging (MRI). By accentuating the effects of this agent through the use of gradient-echo techniques in high fields, we demonstrate in vivo images of brain microvasculature with imag ..."
Abstract - Cited by 648 (1 self) - Add to MetaCart
. This form of contrast is not observed in spin-echo images. Through simulations (9), we have shown that vessels as small as 50 ,um in diameter can be detected in images with a pixel size of 100 pum. We have also demonstrated that the size of the susceptibility-induced local field depends on (i

Hierarchical Modelling and Analysis for Spatial Data. Chapman and Hall/CRC,

by S Banerjee , B P Carlin , A E Gelfand , Chapman , / Hall , New Crc , N York; Cressie , P J Diggle , P J Ribeiro Jr , B D Ripley , 2004
"... Abstract Often, there are two streams in statistical research -one developed by practitioners and other by main stream statisticians. Development of geostatistics is a very good example where pioneering work under realistic assumptions came from mining engineers whereas it is only now that statisti ..."
Abstract - Cited by 442 (45 self) - Add to MetaCart
Abstract Often, there are two streams in statistical research -one developed by practitioners and other by main stream statisticians. Development of geostatistics is a very good example where pioneering work under realistic assumptions came from mining engineers whereas it is only now

The Determinants of Credit Spread Changes.

by Pierre Collin-Dufresne , Robert S Goldstein , J Spencer Martin , Gurdip Bakshi , Greg Bauer , Dave Brown , Francesca Carrieri , Peter Christoffersen , Susan Christoffersen , Greg Duffee , Darrell Duffie , Vihang Errunza , Gifford Fong , Mike Gallmeyer , Laurent Gauthier , Rick Green , John Griffin , Jean Helwege , Kris Jacobs , Chris Jones , Andrew Karolyi , Dilip Madan , David Mauer , Erwan Morellec , Federico Nardari , N R Prabhala , Tony Sanders , Sergei Sarkissian , Bill Schwert , Ken Singleton , Chester Spatt , René Stulz - Journal of Finance , 2001
"... ABSTRACT Using dealer's quotes and transactions prices on straight industrial bonds, we investigate the determinants of credit spread changes. Variables that should in theory determine credit spread changes have rather limited explanatory power. Further, the residuals from this regression are ..."
Abstract - Cited by 422 (2 self) - Add to MetaCart
at both the individual firm level (see, for example, Kwan (1996)) and portfolio level (see, for example, Blume, Keim and Patel (1991), and Cornell and Green (1991)). These studies focus on corporate bond returns, or yield changes. The main conclusions of these papers are: (1) high-grade bonds behave
Results 1 - 10 of 43,489