Acknowledgements : many thanks to professor Giovanni Pighizzini for its welcome and for having directed my internship. Many thanks also to Carlo Mereghetti and Beatrice Palano and all organizing committee of NCMA workshop for having given me the possibility to assist at this workshop. Many thanks also to Viliam Geffert for his contribution to our work. Thanks to Antonio Capoduro for coffees and...

For tabled Lindenmayer systems and their languages, the degree of synchronization and the degree of nondeterminism are well investigated measures of descriptional complexity. In this paper the sequential counterparts of tabled Lindenmayer systems, namely cooperating distributed grammar systems and their pure variant (working in the so called t-mode of derivation) are treated with respect to the...

In a designated verifier signature (DVS) scheme a signer creates a signature which is only verifiable by a designated verifier. A DVS is a useful scheme for authenticating a signer without disturbing her privacy. In a universal DVS (UDVS) scheme, everyone who holds Alice’s traditional signature on a message (the signature holder), is able to transform it to a DVS for a specific verifier. Non-de...

Decision tree pruning is critical for the construction of good decision trees. The most popular and widely used method among various pruning methods is cost-complexity pruning, whose implementation requires a training dataset to develop a full tree and a validation dataset to prune the tree. However, different pruned trees are found to be produced when the original dataset are randomly partitio...

My research interests involve Finite Model Theory and Descriptive Complexity, an area of research nestled in the intersection of Combinatorics, Logic and Computer Science. Inspired by Ehrenfeucht–Fräıssé games, I have been studying local properties of regular colored graphs– in particular, the computational complexity of realizing a given set of neighborhoods in a graph.

Although parallel systems with high peak performance have been exciting, high peak performance often means high power consumption. In this paper, power-aware parallel systems are investigated, where each node can make dynamic voltage scaling (DVS). Based on the characteristics of communication and memory access in MPI programs, a compiler is used to automatically form communication and computat...

Hiermit versichere ich, daa ich die Arbeit selbstt andig verfaat und keine anderen als die angegebenen Quellen und Hilfsmittel benutzt sowie Zitate kenntlich gemacht habe. I have many people to thank and acknowledge. Especially I would like to thank my advisor, Eric Rosen, for all the time he spent in supporting my thesis work.

Real time systems are widely used systems in now days. Most of these systems work in fault prone environment. The job running in these systems should be finished on its deadline as timing constraints which requires some energy to finishing it. If there is any fault occurring in the system then it may not be possible that the job running will finish on its deadline and will give the desired resu...

We consider extensions of xed-point logic by means of generalized quantiiers in the context of descriptive complexity. By the well-known theorem of Immerman and Vardi, xed-point logic captures PTime over linearly ordered structures. It fails, however , to express even most fundamental structural properties, like simple cardinality properties, in the absence of order. In the present investigatio...