In this paper a formal calulus was developed that makes it possible to describe and formally verify processings of synchronously working parallel systems. This calculus made it possible to detect a serious design error in a famous systolic VLSI system ...

This paper provides a first systematic categorization of all possible computational modes in the context of Log-space bounded computations. It was detected that beside of the well-known deterministic and nondeterministic / co-nondeterministic modes there exits merely one additional mode, the firstly characterized parity mode. More you can read here. 

As a generalization of the computational parity mode we newly invent modulo acceptation modes, and define and investigate corresponding Log-space MOD complexity classes.

OBDDs are a famous data structure for the formal verification of electronic micro-cicuits since they allow efficient Boolean synthesis and equivalence testing. It was a great surprise when we could show that same is true for the more compact FBDDs. More you can read here.

Here we introduce and investigate new complexity classes which are characterized by different modes of communication complexity. By proving various exponential lower bounds we are even able to show that these classes are all different when communication complexity is restricted.  

The paper founds the use of ordered binary decisions diagrams  (OBDDs) as a data structure for representing mirco-electronic circuits as well as surveys our contributions to increase their efficiency.  

Shifting ist a powerful technique to find suited variable order which minimize complexity of OBDD-based cuircuit representations and, therefore, enhance OBDD-based synthesis and verification. We considerably improved this method by exploiting and utilizing powerful algebraic techniques.

This paper summarizes our experiences in designing, establishing and maintainining the (worldwide first) electronic colloquium. Focusing on computational complexity ECCC opens new ways for fast and reliable communicating of new scientific results and enhances (Internet-based) scientific discussions.

Our design of a virtual lab opens completely new ways to teach and exercise IT-security. Concept and architecuture of our Tele-Lab "IT-security" was one of the first attemps to utilize virtual machines for e-learning.