Przeglądaj Acta Universitatis Lodziensis. Folia Oeconomica nr 216/2008 według daty wydania
Wyświetlanie pozycji 21-40 z 45
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Estimation of parameters of Tömquist’s functions with Newton-Raphson’s method
(Wydawnictwo Uniwersytetu Łódzkiego, 2008)In the work there has been discussed Newton-Raphson’s iterative method of estimation of parameters of Tömquist’s functions of general class and there are derived formulas of their partial derivatives of Ist and 2nd rank. ... -
On robust inference for the Cox model - the coxrobust package
(Wydawnictwo Uniwersytetu Łódzkiego, 2008)A methodology supporting the COXROBUST package, designed for the robust inference in the Cox regression model, is presented. Basic functions of the package and its data analytic capabilities are described. -
Cluster analysis with clusterSim computer program and R environment
(Wydawnictwo Uniwersytetu Łódzkiego, 2008)The article presents auxiliary functions of clusterSim package (see Walesiak & Dudek (2006)) and selected functions of packages stats, cluster, and ade4, which are applied to solving clustering problems. In addition, the ... -
The modification of stepwise multiple procedure
(Wydawnictwo Uniwersytetu Łódzkiego, 2008)In this paper we discuss stepdown methods that control the familywise error rate in finite samples. Such methods proceed stagewise by testing an intersection hypothesis without regard to hypotheses previously rejected. ... -
Correlation among variables and methods of establishing weights of sample units. Monte Carlo analysis of the modified synthetic estimator
(Wydawnictwo Uniwersytetu Łódzkiego, 2008)In many statistical surveys one faces the problem of insufficient number of sample observations to make reliable inference about a given population domain of interest (small area). One possible solution, which has been ... -
Dispersion of estimates of linear regression parameters in case of the deepest regression method
(Wydawnictwo Uniwersytetu Łódzkiego, 2008)The deepest regression method is such a method of estimation of regression parameters that the maximal regression depth characterises the obtained model. In this paper the deeepest regression method is presented and the ... -
Distribution of linear combination the sample mean and the sample median
(Wydawnictwo Uniwersytetu Łódzkiego, 2008)In the work there is examined the estimator of linear combination of arithmetic mean and median from a random sample of a random variable in the symmetrical distribution. The coefficients of combinations are determined ... -
Remarks on the generalized probability of the bifuzzy event
(Wydawnictwo Uniwersytetu Łódzkiego, 2008)The presentation is a continuation of a paper at MSA’04 (T. Gerstenkorn, J. Gerstenkorn (2007)). In 1978 Ph. Smets proposed the so-called g-probability of a fuzzy event as a generalization of the L. Zadeh’s probability ... -
On Some Composite Estimator of the Population Mean
(Wydawnictwo Uniwersytetu Łódzkiego, 2008)In this paper an estimator of the finite population mean in the unit nonresponse situation is proposed. It is constructed as a combination of the well-known regression estimator derived from the linear model and a ... -
Bootstrap confidence regions based on the Mahalanobis depth measure of two-dimensional samples
(Wydawnictwo Uniwersytetu Łódzkiego, 2008)Construction of confidence regions for multi-dimensional samples is usually performed with a known stochastic distribution of a random vector in question. However, for multidimensional studies of socio-economic phenomena, ... -
Kohonen self-organizing maps for symbolic objects
(Wydawnictwo Uniwersytetu Łódzkiego, 2008)Visualizing data in the form of illustrative diagrams and searching, in these diagrams, for structures, clusters, trends, dependencies etc. is one of the main aims of multivariate statistical analysis. In the case of ... -
On testing the hypothesis of stability of the ratio of two random variables.
(Wydawnictwo Uniwersytetu Łódzkiego, 2008)The problem of testing the hypothesis of the stability of expected value of the ratio of random variables is considered in the article. The ratio of random variables X and Y under assumptions of the autoregression models ... -
Power of tests for multivariate normality based on skewness and flatness coefficients
(Wydawnictwo Uniwersytetu Łódzkiego, 2008)There are many methods of construction of multivariate normality tests. The current review of the literature proves that there are at least 60 procedures of verification of the hypothesis about multivariate normality of ... -
On the properties of some predictor in time series analysis
(Wydawnictwo Uniwersytetu Łódzkiego, 2008)Cieślak (1993) and Kohler and College (1988) considered a predictor being an arithmetic mean of a set of k-latest observations in time series, where k was constant. In this paper a modified predictor is presented and its ... -
Test of multivariate normality using shape measures of the distribution
(Wydawnictwo Uniwersytetu Łódzkiego, 2008)Karl Pearson, in 1990, proposed two numerical characteristics of the distribution of random variables i.e. asymmetry (skewness) and kurtosis (flatness). Their sample approximations allow to describe partially the empirical ... -
Combining different types of classifiers
(Wydawnictwo Uniwersytetu Łódzkiego, 2008)Model fusion has proved to be a very successful strategy for obtaining accurate models in classification and regression. The key issue, however, is the diversity of the component classifiers because classification error ... -
Bayes estimation in agricultural sample surveys in Poland
(Wydawnictwo Uniwersytetu Łódzkiego, 2008)Direct estimators used in sample surveys usually provide parameters’ estimates for country and regions. They do not provide estimates for smaller crosssections (age, gender etc.) or smaller geographical areas (subregions, ... -
Methodological aspects of labour market research based on the labour force survey in Poland
(Wydawnictwo Uniwersytetu Łódzkiego, 2008)The paper focuses on methodological aspects of labour market research on the basis of Labour Force Survey (LFS) in Poland. The analysis shows that methodology covers both the subject of research (the scope of research ... -
A proposal of a new method of choosing starting points for k-means grouping
Korzeniewski, Jerzy
(Wydawnictwo Uniwersytetu Łódzkiego, 2008)
When one groups set elements with the help of k-means it is crucial to choose starting points properly. If they are chosen incorrectly one may arrive at badly grouped elements. In the paper a new method of choosing ... -
Bayesian estimation of bonus malus coefficients in CR automobile liability insurance
Szymańska, Anna (Wydawnictwo Uniwersytetu Łódzkiego, 2008)
The basis of insurance activity is proper premium estimation. The gross premium is the net premium enlarged by a security loading and costs of insurance activity. In the paper individual net premium is calculated by means ...