Ludwig Fahrmeir, Christian Gieger, Christian Heumann
This paper discusses marginal regression for repeated ordinal measurements that are isotonic over time. Such data are often observed in longitudinal studies on healing processes where, due to...
Weighted Mixed Regression Estimation Under Biased Stochastic Restrictions (2007)
The paper considers the construction of estimators of regression coefficients in a linear regression model when some stochastic and biased apriori information is available. Such apriori information...
Stein-Rule Estimation under an Extended Balanced Loss Function (2007)
Toutenburg, Helge, Heumann, Christian
This paper extends the balanced loss function to a more general set up. The ordinary least squares and Stein-rule estimators are exposed to this general loss function with quadratic loss structure in...
Toutenburg, Helge, Heumann, Christian
This paper presents a general loss function under quadratic loss structure and discusses the comparison of risk functions associated with the unbiased least squares and biased Stein-rule estimators...
Toutenburg, Helge, Heumann, Christian
Choosing the performance criterion to be mean squared error matrix, we have compared the least squares and Stein-rule estimators for coefficients in a linear regression model when the disturbances...
Toutenburg, Helge, Heumann, Christian
The risk of the family of feasible generalized double k-class estimators under LINEX loss function is derived in a linear regression model. The disturbances are assumed to be non-spherical and their...
A Review on Joint Models in Biometrical Research (2006)
Neuhaus, Anneke, Augustin, Thomas, Heumann, Christian, Daumer, Martin
In some fields of biometrical research joint modelling of longitudinal measures and event time data has become very popular. This article reviews the work in that area of recent fruitful research by...
Statistische Methoden bei unvollständigen Daten (2004)
Toutenburg, Helge, Heumann, Christian, Nittner, T.
Dieser Artikel gibt einen überblick über die Problematik fehlender Daten im Rahmen der statistischen Datenanalyse. Im Prinzip sollte er auch Lesern mit geringem mathematischen und statistischen...
A review of agreement measure as a subset of association measure between raters (2004)
Adejumo, A. O., Heumann, Christian, Toutenburg, Helge
Agreement can be regarded as a special case of association and not the other way round. Virtually in all life or social science researches, subjects are being classified into categories by raters,...
Adejumo, A. O., Heumann, Christian, Toutenburg, Helge
In almost all life or social science researches, subjects are classified into categories by raters, interviewers or observers. Many approaches have been proposed by various authors for analyzing the...
Adejumo, A. O., Heumann, Christian, Toutenburg, Helge
The Poisson distribution has been widely used for modelling rater agreement using loglinear models. Mostly in all life or social science researches, subjects are being classified into categories by...
Parametric and Nonparametric Regression with Missing X's - A Review (2002)
Toutenburg, Helge, Heumann, Christian, Nittner, T., Scheid, S.
This paper gives a detailed overview of the problem of missing data in parametric and nonparametric regression. Theoretical basics, properties as well as simulation results may help the reader to get...
Intention-to-treat with drop-out (2000)
We consider the problem of an ITT analysis in a randomized clinical trial. Due to (study) drop-outs, standard methods are not applicable and simple imputation methods like LOCF (last observation...
Trevisani, M., Causin, R., Montecchio, L., Kastner, C., Heumann, Christian
This statistical survey originates from the problem of discovering which relationship exists between root ectomycorrhizal infection and health status of forest plants. The sampling scheme takes...
New features in MAREG 0.2.0 (1999)
Kastner, C., Fieger, A., Heumann, Christian
This paper describes changes in the software tool MAREG from version 0.0.7 (July 1997) to version 0.2.0 (June 1999). As these new features are not implemented in WinMAREG yet, they can only be used...
An Application of Isotonic Longitudinal Marginal Regression to Monitoring the Healing Process (1999)
Ludwig Fahrmeir, Christian Gieger, Christian Heumann
This paper discusses marginal regression for repeated ordinal measurements that are isotonic over time. Such data are often observed in longitudinal studies on healing processes where, due to...
Fieger, A., Kastner, C., Heumann, Christian
This paper is a short introduction into the usage of WinMAREG. Two examples are used to illustrate the most common options and features of the software.
Heumann, Christian, Fieger, A., Kastner, C.
Die hier vorgestellten Erweiterungen der bereits bestehenden generischen Bibliothek zur linearen Algebra (Fieger, A., Heumann, C., Kastner, C., Watzka, K., 1997:(Discussion Paper 63) stellen...
Regression modelling with fixed effects - missing values and other problems (1998)
Toutenburg, Helge, Fieger, A., Heumann, Christian
The paper considers new devices to predict the response variable using a convex target function weighting the response and its expectation. A MDEP-matrix superiority condition is given concerning...
Generische Bibliothek zur Linearen Algebra und zur Simulation in C++ (1997)
Fieger, A., Heumann, Christian, Kastner, C., Watzka, K.
Die hier vorgestellte Bibliothek implementiert in statistischen Anwendungsprogrammen haeufig benoetigte Bausteine in einer objektorientierten Sprache. Eine solche Bibliothek tritt ihrem Anwender...
An application of isotonic longitudinal marginal regression to monitoring the healing process (1997)
Fahrmeir, Ludwig, Gieger, Christian, Heumann, Christian
This paper discusses marginal regression for repeated ordinal measurements that are isotonic over time. Such data are often observed in longitudinal studies on healing processes where, due to...
Marginal regression modeling of correlated multicategorical response: A likelihood approach (1996)
A full likelihood approach for marginal regression modeling of correlated multicategorical data is proposed. It is in fact an extension of the approach of Fitzmaurice and Laird (1993) for repeated...
Fieger, A., Heumann, Christian, Kastner, C.
This paper describes a software tool for marginal regression methods. MAREG currently handles binary, categorical and continious data with several link functions. Although intended for the analysis...
Marginal regression modeling of correlated multicategorical response: A likelihood approach (1996)
A full likelihood approach for marginal regression modeling of correlated multicategorical data is proposed. It is in fact an extension of the approach of Fitzmaurice and Laird (1993) for repeated...
Andreas Fieger, Christian Heumann, Christian Kastner
This paper describes a software tool for marginal regression methods. MAREG currently handles binary, categorical and continious data with several link functions. Although intended for the analysis...
Die Wirkung von Superoxidradikalen auf den Stoffwechsel roter Blutzellen. (1988)
Berlin, Humboldt-Univ., Diss. A, 1988 (Nicht f.d. Austausch).