An overview of design of experiments

An overview of the design of statistical experiments is presented, with special emphasis on response surface designs, block designs, neighbor designs. Applications are mentioned for industrial quality improvement, agricultural experiments, biometry. An outlook towards design optimality concludes the survey.     

An upper bound for binary constant weight codes

An upper bound for binary constant weight codes is presented, and several examples which achieve this upper bound are given. Based on this upper bound, some properties of equidistant constant weight codes are obtained. A new proof for Grey–Rankin bound in coding theory is also presented in this paper.     

Understanding Canonical Correlation through the General Linear Model and Principal Components

Canonical correlation has been little used and little understood, even by otherwise sophisticated analysts. An alternative approach to canonical correlation, based on a general linear multivariate model, is presented. Properties of principal component analysis are used to help explain the method. Standard computational methods for full rank canonical correlation, techniques for canonical correlation on component scores, and canonical correlation with less than full rank are discussed. They are seen to be essentially equivalent when the model equation for canonical correlation on component scores is presented. The two approaches to less than full rank situations are equivalent in some senses, but quite different in usefulness, depending on the application. An example dataset is analyzed in detail to help demonstrate the conclusions.     

Bayesian object matching

A Bayesian approach to object matching is presented. An object and a scene are each represented by features, such as critical points, line segments and surface patches, constrained by unary properties and contextual relations. The matching is presented as a labeling problem, where each feature in the scene is assigned (associated with) a feature of the known model objects. The prior distribution of a scene's labeling is modeled as a Markov random field, which encodes the between-object constraints. The conditional distribution of the observed features labeled is assumed to be Gaussian, which encodes the within-object constraints. An optimal solution is defined as a maximum a posteriori estimate. Relationships with previous work are discussed. Experimental results are shown.     

A two-sample parametric group sequential procedure for monitoring clinical trials

A group sequential procedure is presented which allows for staggered entry of patients, random loss to followup, and utilizes the flexible boundary approach of Lan and DeMets. The proposed procedure assumes that response times are nearly exponentially distributed. An example as well as simulation studies comparing the performance of the proposed procedure with the group sequential logrank are also presented.     

The mean of linear signed rank statistics under alternatives

An expression is presented for the mean of a linear signed rank statistic for the one sample location model. Several examples are given to illustrate its application.     

Asymptotic inference for coefficients of variation

Asymptotic inference results for the coefficients of variation of normal populations are presented in this article. This includes formulas for test statistics, power, confidence intervals, and simultaneous inference. The results are based on the asymptotic normality of the sample coefficient of variation as derived by Miller (1991). An example which compares the homogeneity of bone test samples produced from two different methods is presented.     

Shape change along geodesics with application to cleft lip surgery

Continuous shape change is represented as curves in the shape space. A method for checking the closeness of these curves to a geodesic is presented. Three large databases of short human motions are considered and shown to be well approximated by geodesics. The motions are thus approximated by two shapes on the geodesic and the rate of progress along the path. An analysis of facial motion data taken from a study of subjects with cleft lip or cleft palate is presented that allows the motion to be considered independently from the static shape. Inferential methods for assessing the change in motion are presented. The construction of predicted animated motions is discussed.     

The negative multinomial logit model

A polychotomous logit model is defined for negative multinomial frequency counts within independent populations. An efficient estimator of the model parameters and estimator covariance matrix is given in closed form. Minimum chi-square and Wald tests are presented.     

Efficient maximin distance designs for experiments in mixtures

In this paper, different dissimilarity measures are investigated to construct maximin designs for compositional data. Specifically, the effect of different dissimilarity measures on the maximin design criterion for two case studies is presented. Design evaluation criteria are proposed to distinguish between the maximin designs generated. An optimization algorithm is also presented. Divergence is found to be the best dissimilarity measure to use in combination with the maximin design criterion for creating space-filling designs for mixture variables.     

Mapping water quality by local scoring

The mean density of bacteria in a water body is commonly monitored using quantal assay. This paper describes the use of local scoring in estimating the spatial distribution of mean density from quantal assay results at a set of point locations. An application to estimating the mean density of fecal conform bacteria in a coastal pond is presented. Model diagnostics based on a parametric bootstrap are also presented.     

A Decomposition of Pearson–Fisher and Dzhaparidze–Nikulin Statistics and Some Ideas for a More Powerful Test Construction

An explicit decomposition on asymptotically independent distributed as chi-squared with one degree of freedom components of the Pearson–Fisher and Dzhaparidze–Nikulin tests is presented. The decomposition is formally the same for both tests and is valid for any partitioning of a sample space. Vector-valued tests, components of which can be not only different scalar tests based on the same sample, but also scalar tests based on components or groups of components of the same statistic are considered. Numerical examples illustrating the idea are presented.     

The “Caterpillar”-SSA method for analysis of time series with missing values

The paper concerns the problem of applying singular spectrum analysis to time series with missing data. A method of filling in the missing data is proposed and is applied to time series of finite rank. Conditions of exact reconstruction of missing data are developed and versions of the algorithm applicable to real-life time series are presented. The proposed algorithms result in the extraction of additive components of time series such as trends and periodic components, with simultaneous filling in of the missing data. An example is presented.     

Quadratic estimation in mixed linear models with two variance components

Explicit expressions for Bayes invariant quadratic estimates, biased and unbiased, are presented and proved to cover the entire class of admissible estimates in the considered classes. An unbalanced genetic model is studied for demonstration.     

The indicator formalism in spatial statistics

In this paper the indicator approach in spatial data analysis is presented for the determination of probability distributions to characterize the uncertainty about any unknown value. Such an analysis is non-parametric and is done independently of the estimate retained. These distributions are given through a series of quantile estimates and are not related to any particular prior model or shape. Moreover, determination of these distributions accounts for the data configuration and data values. An application is discussed. Moreover, some properties related to the Gaussian model are presented.     

Boundary bias correction in nonparametric density estimation

An approach for removing boundary bias in nonparametric density esti-mation is considered. The technique is based on suitable finite-dimensional projections in Hilbert space. Applications to boundary bias removal with kernel and trigonometric series estimators are presented.     

The jackknife procedure for the probabilities of misclassification

Seven estimators for the probabilities of misclassifi-cation associated with the linear discriminant function are considered. Four of them are known in the literature. The remaining three are constructed through the Jackknife Pro-cedure. An empirical investigation is conducted to evalu-ate the relative merits of these estimators. Summary of the results is presented.     

Generating random points in a polytope

An algorithm is presented for generating pseudorandom variates distributed uniformly over an arbitrary convex polytope in a Euclidean space of arbitrary dimension. Many commonly used methods for generating uniform variates require that the polytope be expressed as the solution set of a system of linear inequalities; the algorithm presented here requires instead that the polytope be presented in terms of a finite generating set, typically the set of its vertices. Included in the algorithm are procedures for identifying all faces of the polytope and for decomposing the polytope into simplices.     

The minimum discrimination information approach in analyzing categorical data

A brief review of the minimum discrimination information (MDI) approach in analyzing categorical data is presented in a question -answer format, An example is given to bring out situations in which the MDI approach is more useful. No new results are proved.     

Estimation for aggregate models: The aggregate Markov chain

An argument in favour of projecting the score function for models involving incomplete data is presented. Projection is then applied to the aggregate Markov-chain model resulting in weighted least-squares estimators. The limit theory and efficiency of these estimators are studied using martingale limit theory.