Results 1  10
of
25
Higher criticism for detecting sparse heterogeneous mixtures
 Ann. Statist
, 2004
"... Higher Criticism, or secondlevel significance testing, is a multiple comparisons concept mentioned in passing by Tukey (1976). It concerns a situation where there are many independent tests of significance and one is interested in rejecting the joint null hypothesis. Tukey suggested to compare the ..."
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Cited by 88 (15 self)
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Higher Criticism, or secondlevel significance testing, is a multiple comparisons concept mentioned in passing by Tukey (1976). It concerns a situation where there are many independent tests of significance and one is interested in rejecting the joint null hypothesis. Tukey suggested to compare the fraction of observed significances at a given αlevel to the expected fraction under the joint null, in fact he suggested to standardize the difference of the two quantities and form a zscore; the resulting zscore tests the significance of the body of significance tests. We consider a generalization, where we maximize this zscore over a range of significance levels 0 < α ≤ α0. We are able to show that the resulting Higher Criticism statistic is effective at resolving a very subtle testing problem: testing whether n normal means are all zero versus the alternative that a small fraction is nonzero. The subtlety of this ‘sparse normal means ’ testing problem can be seen from work of Ingster (1999) and Jin (2002), who studied such problems in great detail. In their studies, they identified an interesting range of cases where the small fraction of nonzero means is so
Test of significance when data are curves
 Journal of the American Statistical Association
, 1998
"... With modern technology, massive data can easily be collected in a form of multiple sets of curves. New statistical challenge includes testing whether there is any statistically significant difference among these sets of curves. In this paper, we propose some new tests for comparing two groups of cur ..."
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Cited by 31 (1 self)
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With modern technology, massive data can easily be collected in a form of multiple sets of curves. New statistical challenge includes testing whether there is any statistically significant difference among these sets of curves. In this paper, we propose some new tests for comparing two groups of curves based on the adaptive Neyman test and the wavelet thresholding techniques introduced in Fan (1996). We demonstrate that these tests inherit the properties outlined in Fan (1996) and they are simple and powerful for detecting di erences between two sets of curves. We then further generalize the idea to compare multiple sets of curves, resulting in an adaptive highdimensional analysis of variance, called HANOVA. These newly developed techniques are illustrated by using a dataset on pizza commercial where observations are curves and an analysis of cornea topography in ophthalmology where images of individuals are observed. A simulation example is also presented to illustrate the power of the adaptive Neyman test.
GoodnessofFit Tests for Parametric Regression Models
 JOUR. AMERI. STATIST. ASSOC
, 2001
"... Several new tests are proposed for examining the adequacy of a family of parametric models against large nonparametric alternatives. These tests formally check if the bias vector of residuals from parametric ts is negligible by using the adaptive Neyman test and other methods. The testing procedures ..."
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Cited by 19 (5 self)
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Several new tests are proposed for examining the adequacy of a family of parametric models against large nonparametric alternatives. These tests formally check if the bias vector of residuals from parametric ts is negligible by using the adaptive Neyman test and other methods. The testing procedures formalize the traditional model diagnostic tools based on residual plots. We examine the rates of contiguous alternatives that can be detected consistently by the adaptive Neyman test. Applications of the procedures to the partially linear models are thoroughly discussed. Our simulation studies show that the new testing procedures are indeed powerful and omnibus. The power of the proposed tests is comparable to the Ftest statistic even in the situations where F test is known to be suitable and can be far more powerful than the Ftest statistic in other situations. An application to testing linear models versus additive models are discussed.
Strong approximation for the sums of squares of augmented GARCH sequences
 Bernoulli
, 2006
"... Abstract: We study so–called augmented GARCH sequences, which include many submodels of considerable interest, such as polynomial and exponential GARCH. To model the returns of speculative assets, it is particularly important to understand the behaviour of the squares of the observations. The main ..."
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Cited by 10 (3 self)
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Abstract: We study so–called augmented GARCH sequences, which include many submodels of considerable interest, such as polynomial and exponential GARCH. To model the returns of speculative assets, it is particularly important to understand the behaviour of the squares of the observations. The main aim of this paper is to present a strong approximation for the sum of the squares. This will be achieved by an approximation of the volatility sequence with a sequence of blockwise independent random variables. Furthermore, we derive a necessary and sufficient condition for the existence of a unique (strictly) stationary solution of the general augmented GARCH equations. Also, necessary and sufficient conditions for the finiteness of moments are provided.
Goodnessoffit tests via phidivergences
, 2006
"... A unified family of goodnessoffit tests based on φdivergences is introduced and studied. The new family of test statistics Sn(s) includes both the supremum version of the Anderson–Darling statistic and the test statistic of Berk and Jones [Z. Wahrsch. Verw. Gebiete 47 (1979) 47–59] as special cas ..."
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Cited by 8 (1 self)
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A unified family of goodnessoffit tests based on φdivergences is introduced and studied. The new family of test statistics Sn(s) includes both the supremum version of the Anderson–Darling statistic and the test statistic of Berk and Jones [Z. Wahrsch. Verw. Gebiete 47 (1979) 47–59] as special cases (s = 2 and s = 1, resp.). We also introduce integral versions of the new statistics. We show that the asymptotic null distribution theory of Berk
A note on the asymptotic distribution of BerkJones type statistics under the null hypothesis
 In High Dimensional Probability, III (Sandjberg
, 2003
"... ..."
Stochastic bifurcation models
 Ann. Probab
, 1999
"... Abstract. We study an ordinary differential equation controlled by a stochastic process. We present results on existence and uniqueness of solutions, on associated local times (Trotter and RayKnight theorems), and on time and direction of bifurcation. A relationship with Lipschitz approximations to ..."
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Cited by 6 (3 self)
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Abstract. We study an ordinary differential equation controlled by a stochastic process. We present results on existence and uniqueness of solutions, on associated local times (Trotter and RayKnight theorems), and on time and direction of bifurcation. A relationship with Lipschitz approximations to Brownian paths is also discussed. Research partially supported by NSF grant DMS9700721. 1 1. Introduction. Let Bt be a continuous function of t, let t0, x0, β1, β2 ∈ R, and consider the ordinary differential equation dXt
Extremevalue analysis of standardized gaussian increments
, 2008
"... Let {Xi,i = 1,2,...} be i.i.d. standard gaussian variables. Let Sn = X1 +... + Xn be the sequence of partial sums and ..."
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Cited by 5 (0 self)
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Let {Xi,i = 1,2,...} be i.i.d. standard gaussian variables. Let Sn = X1 +... + Xn be the sequence of partial sums and
THE LIMIT DISTRIBUTION OF THE MAXIMUM INCREMENT OF A RANDOM WALK WITH REGULARLY VARYING JUMP SIZE DISTRIBUTION
, 2009
"... In this paper we deal with the asymptotic distribution of the maximum increment of a random walk with a regularly varying jump size distribution. This problem is motivated by a longstanding problem on change point detection for epidemic alternatives. It turns out that the limit distribution of the ..."
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Cited by 1 (1 self)
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In this paper we deal with the asymptotic distribution of the maximum increment of a random walk with a regularly varying jump size distribution. This problem is motivated by a longstanding problem on change point detection for epidemic alternatives. It turns out that the limit distribution of the maximum increment of the random walk is one of the classical extreme value distributions, the Fréchet distribution. We prove the results in the general framework of point processes and for jump sizes taking values in a separable Banach space.