共查询到20条相似文献,搜索用时 46 毫秒
1.
The Significance Analysis of Microarrays (SAM; Tusher et al., 2001) method is widely used in analyzing gene expression data while controlling the FDR by using resampling-based procedure in the microarray setting. One of the main components of the SAM procedure is the adjustment of the test statistic. The introduction of the fudge factor to the test statistic aims at deflating the large value of test statistics due to the small standard error of gene-expression. Lin et al. (2008) pointed out that the fudge factor does not effectively improve the power and the control of the FDR as compared to the SAM procedure without the fudge factor in the presence of small variance genes. Motivated by the simulation results presented in Lin et al. (2008), in this article, we extend our study to compare several methods for choosing the fudge factor in the modified t-type test statistics and use simulation studies to investigate the power and the control of the FDR of the considered methods. 相似文献
2.
Shesh N. Rai Jianmin Pan Xiaobin Yuan Jianguo Sun Melissa M. Hudson Deo K. Srivastava 《统计学通讯:理论与方法》2013,42(17):3117-3133
New drug discovery in the pediatrics has dramatically improved survival, but with long- term adverse events. This motivates the examination of adverse outcomes such as long-term toxicity in a phase IV trial. An ideal approach to monitor long-term toxicity is to systematically follow the survivors, which is generally not feasible. Instead, cross-sectional surveys are conducted in Hudson et al. (2007), with one of the objectives to estimate the cumulative incidence rates along with specific interest in fixed-term (5 or 10 year) rates. We present inference procedures based on current status data to our motivating example with very interesting findings. 相似文献
3.
Based on the semiparametric median regression analysis for the right-censored data developed by Ying et al. (1995), an empirical likelihood based inferential procedure for the regression coefficients is proposed. The limiting distribution of the proposed log-empirical likelihood ratio test statistic follows a chi-squared distribution, which corresponds to the standard asymptotic results of the empirical likelihood method. The inference about the subsets of the entire regression coefficients vector is discussed. The proposed method is illustrated by some simulation studies. 相似文献
4.
Qian Chen 《统计学通讯:模拟与计算》2013,42(4):789-804
We consider the relative merits of various saddlepoint approximations for the cumulative distribution function (cdf) of a statistic with a possibly non normal limit distribution. In addition to the usual Lugannani-Rice approximation, we also consider approximations based on higher-order expansions, including the case where the base distribution for the approximation is taken to be non normal. This extends earlier work by Wood et al. (1993). These approximations are applied to the distribution of the Anderson-Darling test statistic. While these generalizations perform well in the middle of the distribution's support, a conventional normal-based Lugannani-Rice approximation (Giles, 2001) is superior for conventional critical regions. 相似文献
5.
Robert M. Adams 《统计学通讯:理论与方法》2013,42(13):2425-2442
This article generalizes results from Park et al. (1998) and Adams et al. (1999) on semiparametric efficient estimation of panel models. The form of semiparametric efficient estimators depends on the statistical assumptions imposed. Normality assumptions on the transitory error are sometimes inappropriate. We relax the normality assumption used in the articles above to derive more general semiparametric efficient estimators. These estimators are illustrated in a Monte Carlo simulation and an analysis of banking productivity. 相似文献
6.
Suchandan Kayal 《统计学通讯:理论与方法》2018,47(20):4938-4957
Several probability distributions such as power-Pareto distribution (see Gilchrist 2000 and Hankin and Lee 2006), various forms of lambda distributions (see Ramberg and Schmeiser 1974 and Freimer et al. 1988), Govindarajulu distribution (see Nair, Sankaran, and Vineshkumar 2012), etc., do not have manageable distribution functions, though they have tractable quantile functions. Hence, analytical study of the properties of Chernoff distance of two random variables associated with these distributions via traditional distribution function-based tool becomes difficult. To make this simple, in this paper, we introduce quantile-based Chernoff distance for (left or right) truncated random variables and study its various properties. Some useful bounds as well as characterization results are obtained. 相似文献
7.
Accelerated failure time models are useful in survival data analysis, but such models have received little attention in the context of measurement error. In this paper we discuss an accelerated failure time model for bivariate survival data with covariates subject to measurement error. In particular, methods based on the marginal and joint models are considered. Consistency and efficiency of the resultant estimators are investigated. Simulation studies are carried out to evaluate the performance of the estimators as well as the impact of ignoring the measurement error of covariates. As an illustration we apply the proposed methods to analyze a data set arising from the Busselton Health Study (Knuiman et al., 1994). 相似文献
8.
Feng-Shou Ko 《统计学通讯:理论与方法》2013,42(15):2681-2698
A proposed method based on frailty models is used to identify longitudinal biomarkers or surrogates for a multivariate survival. This method is an extention of earlier models by Wulfsohn and Tsiatis (1997) and Song et al. (2002). In this article, similar to Henderson et al. (2002), a joint likelihood function combines the likelihood functions of the longitudinal biomarkers and the multivariate survival times. We use simulations to explore how the number of individuals, the number of time points per individual and the functional form of the random effects from the longitudianl biomarkers influence the power to detect the association of a longitudinal biomarker and the multivariate survival time. The proposed method is illustrate by using the gastric cancer data. 相似文献
9.
Here, we apply the smoothing technique proposed by Chaubey et al. (2007) for the empirical survival function studied in Bagai and Prakasa Rao (1991) for a sequence of stationary non-negative associated random variables.The derivative of this estimator in turn is used to propose a nonparametric density estimator. The asymptotic properties of the resulting estimators are studied and contrasted with some other competing estimators. A simulation study is carried out comparing the recent estimator based on the Poisson weights (Chaubey et al., 2011) showing that the two estimators have comparable finite sample global as well as local behavior. 相似文献
10.
ABSTRACTIn the present paper, we discuss algorithms of record generation when records are taken from a normal population. We propose three new generation algorithms, compare their efficiency and find the most efficient algorithm (Algorithm 2.1). We then compare these algorithms with known generation algorithms presented in the work of Balakrishnan, So, and Zhu (2016). 相似文献
11.
Soo Hak Sung 《统计学通讯:理论与方法》2013,42(9):1663-1674
A complete convergence theorem for an array of rowwise independent random variables was established by Sung et al. (2005). This result has been generalized and extended by Kruglov et al. (2006) and Chen et al. (2007). In this article, we extend the results of Sung et al. (2005), Kruglov et al. (2006), and Chen et al. (2007) to an array of dependent random variables satisfying Hoffmann-Jørgensen type inequalities. 相似文献
12.
Hafiz M. R. Khan 《统计学通讯:理论与方法》2013,42(24):4427-4438
The purpose of this article is to investigate the predictive inference for responses from the location parameter mean as well as from the median given a doubly censored sample from the two-parameter Rayleigh model. The predictive results by Khan et al. (2010) are used to obtain the predictive inference for responses from the median, where Khan et al. (2010) obtained the future estimates from the mean. A numerical example representing 66 liver cancer patients is used for predictive analysis. It is concluded that the predictive inference from the median gives precise results as compared with the location parameter mean. 相似文献
13.
We consider a new generalization of the skew-normal distribution introduced by Azzalini (1985). We denote this distribution Beta skew-normal (BSN) since it is a special case of the Beta generated distribution (Jones, 2004). Some properties of the BSN are studied. We pay attention to some generalizations of the skew-normal distribution (Bahrami et al., 2009; Sharafi and Behboodian, 2008; Yadegari et al., 2008) and to their relations with the BSN. 相似文献
14.
Panel count data frequently occur in many situations including medical follow-up studies and reliability experiments. For two-sample comparison based on panel count data, several procedures have been proposed including Thall and Lachin (1988) and Sun and Fang (2003). In this article, a new class of nonparametric test procedures are presented. The test is a generalization of that for the same problem for failure time data and overcomes some shortcomings of the existing methods. Monte Carlo simulation studies are conducted to evaluate the presented approach and suggest that it works well. An illustrative example is discussed. 相似文献
15.
16.
The approximate D s -optimal design for discriminating between linear and quadratic log contrast models for experiments with mixtures suggested by Aitchison and Bacon-Shone (1984) is investigated, where the experimental domain is restricted further as in Chan (1992). It is found that for a symmetric subspace of the finite dimensional simplex, there is a D s -optimal design with the nice structure that puts a weight 1/2 k?1 on the centroid of this subspace and the remaining weight is uniformly distributed on the vertices of the experimental domain. Finally, the D s -efficiency of the D-optimal design for quadratic model and the design given by Aitchison and Bacon-Shone (1984) are also discussed. 相似文献
17.
Hidetoshi Murakami 《统计学通讯:模拟与计算》2013,42(10):2214-2219
The approximation for the distribution function of test statistic is extremely important in statistics. The standard and higher-order saddlepoint approximations are considered in tails of the limiting distribution for the modified Anderson–Darling test. The saddlepoint approximations are compared with the approximation of Sinclair et al. (1990) for upper tail area. An empirical function is derived to estimate the critical values of a saddlepoint approximation. 相似文献
18.
Abdullah Yilmaz 《统计学通讯:理论与方法》2013,42(23):7053-7059
ABSTRACTSkew-symmetric distributions have been discussed by several research-ers. In this article we construct a skew-symmetric Laplace distribution, which is the generalization of distribution given by Ali et al. (2009) and Nekoukhou and Alamatsaz (2012). This new distribution contains more parameters, and this induces flexibility properties, such as unimodality or bimodality. We study on some properties of this distribution. In the last section we also provide an application with a real data. Concerning example has recently been discussed by Nekoukhou et al. (2013) to apply to their model. We compare the behavior of our distribution to their distribution on this example. 相似文献
19.
In this article, we consider a new insurance risk model based on the entrance process proposed in Li et al. (2005), and investigate the finite time ruin probabilities of this model. It is showed that an exponential upper bound for the finite time ruin probability exists, when the distributions of the claim size are light tailed. Furthermore, when the distributions of the claim size are heavy tailed, an asymptotic formula for the finite time ruin probability is obtained. 相似文献
20.
We derive general formulae for the second-order biases of maximum likelihood estimates of the parameters in generalized nonlinear models with dispersion covariates. This result generalizes previous work by Botter and Cordeiro (1998) and Cordeiro and McCullagh (1991). The practical use of such bias corrections is illustrated in a simulation study. 相似文献