Prof. Dr. Jochen Ziegenbalg 

In addition to the material on my German (primary) homepage, here is some material in English.

Curriculum Vitae in English 

Some internet based materials in English   
  Interactive experiments and simulations
  Computeralgebra notebooks in Mathematica 
(More notebooks in German can be found on my German homepage.) 
    1. Mathematical Modelling, Dynamic Processes and Difference Equations

1.1 Introduction
1.2 Cobweb Diagrams 
1.3 Closed Form Representation  


2. Mean values      

2.1 Pythagorean Means
    3. Elementary Number Theory, Applications and Visualisation

3.1 Phi, Tau, Sigma in Elementary Number Theory   
3.2 Figurate Numbers 

    4.  Huffman Code  

4.1 Huffman Code   

Computeralgebra notebooks / worksheets in Maxima 
The following Maxima notebooks (or "worksheets") are stored in the wxmx  format.  They can be downloaded and should be opened using the Open Source Maxima computeralgebra system (CAS)  with the wxMaxima frontend  (enabling the worksheet functions, modules or procedures to be evaluated interactively).  
Download site for Maxima / wxMaxima:  see e.g.     
1.  Some historical algorithms
2.  Modeling and Simulation