We consider a random design model based on independent and identically distributed pairs of observations (Xi, Yi), where the regression function m(x) is given by m(x) = E(Yi|Xi = x) with one independent variable. In a nonparametric setting the aim is to produce a reasonable approximation to the...

We propose a new method to find spatially adaptive smoothing splines. This new method breaks down the interval [0, 1] into p disjoint sub-intervals. Then we define p functional components in [0, 1], which have two importantfeatures. First, the purpose of each of these p components is to estimate...

A time series analysis was performed on medical scheme statistics with the aim of determining current and future demographic and economic trends. This would enable one to reach a better perspective on the current and future financial dilemma presently experienced by medical schemes. Data for the...

We apply semiparametric efficient estimation procedures for a seemingly unrelated regression model where the multivariate error density is elliptically symmetric to study the efficiency of the foreign exchange market. We consider both cointegrating regressions and standard stationary...

Functional data analysis (FDA) is an active field of statistics, in which the primary subjectsin the study are curves. My dissertation consists of two innovative applications offunctional data analysis in biology. The data that motivated the research broadened thescope of FDA and demanded new...

Statistical flowgraphs represent multistate semi-Markov processes using integral transforms of transition time distributions between adjacent states; these are combinedalgebraically and inverted to derive parametric estimates for first passage time distributions between nonadjacent states. This...

Der Beitrag analysiert den Einfluss der Kundenzufriedenheit auf den ökonomischen Erfolg im Naturkostfachhandel. Auf Basis einer Befragung von 885 Kunden und der Analyse der Betriebskennzahlen von 11 Naturkostfachgeschäften zeigt sich, dass die Kundenzufriedenheit ein relevanter Erfolgsfaktor...

Die Dissertationsarbeit hat zum Ziel, die Gültigkeit der Aussagen eines außenhandelstheoretischen Ansatzes der Neo-Heckscher-Ohlin-Modellklasse in der realen Welt zu überprüfen. Der gewählte Modellierungstyp erlaubt die Koexistenz internationalen intra- und inter-industriellen Handels. Da...

This paper investigates the effects of ordinal regressors in linear regression models. Each ordered categorical variable is interpreted as a rough measurement of an underlying continuous variable as it is often done in microeconometrics for the dependent variable. It is shown that using ordinal...

Die Arbeit beschreibt die Methodiken des Data Mining. Im Fokus steht hierbei die Modellierung der Verfahren KNN, Entscheidungsbaum und Regression. Bei der Durchführung von Fallstudien wird u.a. auf das Pre-Processing eingegangen.