Displaying 101 – 120 of 125

Showing per page

Selective generalized F tests

C. Nunes, J. T. Mexia (2004)

Discussiones Mathematicae Probability and Statistics

Generalized F tests were introduced by Michalski and Zmyślony (1996) for variance components and later (1999) for linear functions of parameters in mixed linear models. We now use generalized polar coordinates to obtain, for the second case, tests that are more powerful for selected families of alternatives.

Sensitivity studies of pollutant concentrations calculated by the UNI-DEM with respect to the input emissions

Ivan Dimov, Raya Georgieva, Tzvetan Ostromsky, Zahari Zlatev (2013)

Open Mathematics

The influence of emission levels on the concentrations of four important air pollutants (ammonia, ozone, ammonium sulphate and ammonium nitrate) over three European cities (Milan, Manchester, and Edinburgh) with different geographical locations is considered. Sensitivity analysis of the output of the Unified Danish Eulerian Model according to emission levels is provided. The Sobol’ variance-based approach for global sensitivity analysis has been applied to compute the corresponding sensitivity measures....

Some inferential questions in regard to analysing two-way Layouts and associated linear model theory and practice

Brenton R. Clarke, Antony G. Monaco (2004)

Discussiones Mathematicae Probability and Statistics

In analysing a well known data set from the literature which can be thought of as a two-way layout it transpires that a robust adaptive regression approach for identifying outliers fails to be sensitive enough to detect the possible interchange of two observations. On the other hand if one takes the classical approach of diagnostic checking one may also stop too early and be satisfied with a model that falls short of a more detailed analysis that takes account of heteroscedasticity in the data....

Strictly associated models, prime basis factorials: an application

Francisco Carvalho (2011)

Discussiones Mathematicae Probability and Statistics

Mixed models will be considered using the Commutative Jordan Algebra of Symmetric matrices approach. Prime basis factorial models will now be considered in the framework provided by Commutative Jordan Algebra of Symmetric matrices. This will enable to obtain fractional replicates when the number of levels is neither a prime or a power of a prime. We present an application to the effect of lidocaine, at an enzymatic level, on the heart muscle of beagle dogs

The linear model with variance-covariance components and jackknife estimation

Jaromír Kudeláš (1994)

Applications of Mathematics

Let θ * be a biased estimate of the parameter ϑ based on all observations x 1 , , x n and let θ - i * ( i = 1 , 2 , , n ) be the same estimate of the parameter ϑ obtained after deletion of the i -th observation. If the expectation of the estimators θ * and θ - i * are expressed as E ( θ * ) = ϑ + a ( n ) b ( ϑ ) E ( θ - i * ) = ϑ + a ( n - 1 ) b ( ϑ ) i = 1 , 2 , , n , where a ( n ) is a known sequence of real numbers and b ( ϑ ) is a function of ϑ , then this system of equations can be regarded as a linear model. The least squares method gives the generalized jackknife estimator. Using this method, it is possible to obtain the unbiased...

The two-dimensional linear relation in the errors-in-variables model with replication of one variable

Anna Czapkiewicz, Antoni Dawidowicz (2000)

Applicationes Mathematicae

We present a two-dimensional linear regression model where both variables are subject to error. We discuss a model where one variable of each pair of observables is repeated. We suggest two methods to construct consistent estimators: the maximum likelihood method and the method which applies variance components theory. We study asymptotic properties of these estimators. We prove that the asymptotic variances of the estimators of regression slopes for both methods are comparable.

Uncertainty of coordinates and looking for dispersion of GPS receiver

Pavel Tuček, Jaroslav Marek (2006)

Acta Universitatis Palackianae Olomucensis. Facultas Rerum Naturalium. Mathematica

The aim of the paper is to show some possible statistical solution of the estimation of the dispersion of the GPS receiver. The presented method (based on theory of linear model with additional constraints of type I) can serve for an improvement of the accuracy of estimators of coordinates acquired from the GPS receiver.

Variance components and nonlinearity

Lubomír Kubáček, Eva Tesaříková (2006)

Acta Universitatis Palackianae Olomucensis. Facultas Rerum Naturalium. Mathematica

Unknown parameters of the covariance matrix (variance components) of the observation vector in regression models are an unpleasant obstacle in a construction of the best estimator of the unknown parameters of the mean value of the observation vector. Estimators of variance componets must be utilized and then it is difficult to obtain the distribution of the estimators of the mean value parameters. The situation is more complicated in the case of nonlinearity of the regression model. The aim of the...

Currently displaying 101 – 120 of 125