This article proposes a new procedure for obtaining one-sided tolerance limits in unbalanced random effects models. The procedure is a generalization of that proposed by Mee and Owen for the balanced situation, and ca...
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This article proposes a new procedure for obtaining one-sided tolerance limits in unbalanced random effects models. The procedure is a generalization of that proposed by Mee and Owen for the balanced situation, and can be easily implemented, because it only needs a non-central-t table. Two simulation studies are carried out to assess the performance of the new procedure and to compare it with one of the other procedures laid out in previous statistical literature. The article findings show that the new procedure is much simpler to compute and performs better than the previous ones, having inferior values of the gamma bias in a wide range of situations, representative of many actual industrial applications, and behaving also reasonably well in more extreme sampling situations. The use of the new limits is illustrated by an application to an actual example from the steel industry.
This paper provides a design method for two-degrees-of-freedom I-PD (2DOF-I-PD) controllers including switched PD compensator based on bilinear matrix inequalities (BMIs). Two design specifications based on H-2 norm a...
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ISBN:
(纸本)0780383354
This paper provides a design method for two-degrees-of-freedom I-PD (2DOF-I-PD) controllers including switched PD compensator based on bilinear matrix inequalities (BMIs). Two design specifications based on H-2 norm are formulated in BMIs, and PID parameters can be exactly obtained by solving the BMI problems via branch and bound algorithms. A set of PD compensators can be obtained simultaneously using proposing design method. The most effective parameter is selected out of the set of PD compensator based on the switching criterion which obtained from estimated system conditions using the statistic algorithms. Numerical examples are also shown.
Recent advances in the study of global patterns of gene expression with the use of microarray technology, coupled with data analysis using sophisticated statistical algorithms, have provided new insights into pathogen...
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Recent advances in the study of global patterns of gene expression with the use of microarray technology, coupled with data analysis using sophisticated statistical algorithms, have provided new insights into pathogenic mechanisms of disease. Complementary and reproducible data from multiple laboratories have documented the feasibility of analysis of heterogeneous populations of peripheral blood mononuclear cells from patients with rheumatic diseases through use of this powerful technology. Although some patterns of gene expression, including increased expression of immune system cell surface activation molecules, confirm previous data obtained with other techniques, some novel genes that are differentially expressed have been identified. Most interesting is the dominant pattern of interferon-induced gene expression detected among blood mononuclear cells from patients with systemic lupus erythematosus and juvenile dermatomyositis. These data are consistent with long-standing observations indicating increased circulating interferon-alpha in the blood of patients with active lupus, but draw attention to the dominance of the interferon pathway in the hierarchy of gene expression pathways implicated in systemic autoimmunity.
Image degradation by blurring is a well-known phenomenon often described by the mathematical operation of convolution. Fourier methods are well developed for recovery, or restoration, of the true image from an observe...
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Image degradation by blurring is a well-known phenomenon often described by the mathematical operation of convolution. Fourier methods are well developed for recovery, or restoration, of the true image from an observed image affected by convolution blur and additive constant variance Gaussian noise. One focus of this paper is to describe another statistical restoration method which is available when the image data exhibits Poisson variability. This is a common situation when counts of recorded activity from the image, as in medical imaging contexts. We apply Maximum Likelihood (ML) and Maximum Penalized Likelihood (MPL) procedures to deconvolve image data which has been degraded by blurring and Poisson variability in recorded activity. A second focus is formulation and comparison of automated selection procedures for regularization (smoothing) parameters in this context. (C) 1998 Elsevier Science B.V. All rights reserved.
The theory of wavelets has recently undergone a period of rapid development. We introduce a software package called wavethresh that works within the statistical language S to perform one- and two-dimensional discrete ...
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Cornish and Fisher (1937) gave the first few terms of the formal expansions for the distribution and percentiles of an asymptotically normal random variable (r.v.) in terms of its cumulants. They also showed that thes...
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Cornish and Fisher (1937) gave the first few terms of the formal expansions for the distribution and percentiles of an asymptotically normal random variable (r.v.) in terms of its cumulants. They also showed that these expansions can sometimes produce extremely accurate approximations. In practice the cumulants are first expanded as a power series in a known parameter n (such as the sample size or degrees of freedom), and these expansions are substituted into the Edgeworth and Cornish-Fisher expansions, which are then rearranged in powers of 1/√ n and truncated. This paper gives explicit formulae for the general terms both for the Cornish-Fisher expansions and for the derived expansions.
The influence of computers on the teaching of statistics at university level is surveyed by considering recent research which, by virtue of its use of the immense power of modern computers, has radically transformed s...
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The influence of computers on the teaching of statistics at university level is surveyed by considering recent research which, by virtue of its use of the immense power of modern computers, has radically transformed statistical practice and which, in turn, is modifying what and how we teach statistics to the next generation of statisticians.
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