101 research outputs found
Remarks on regulated limited ETOL systems and regulated context-free grammars
We continue the studies of the second author on regulated uniformly k-limited and regulated k-limited ETOL systems. We focus on the permitting and forbidding random context regulation. Especially, we establish some results on (regulated) propagating (uniformly) k-limited ETOL systems which were not solved in [2, 18, 21, 22]. Moreover, relations to recurrent programmed languages introduced by von Solms are exhibited. (orig.)Available from TIB Hannover: RR 4367(96-19) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman
An efficient fixed parameter algorithm for 3-Hitting Set
Given a collection of subsets of size three of a finite set S and a positive integer k, the 3-Hitting Set problem is to determine a subset S' subset or equal S with vertical stroke S' vertical stroke #<=#k, so that S' contains at least one element from each subset in C. The problem is NP-complete, and is motivated, for example, by applications in computational biology. Improving previous work, we give a O(2.311"k+n) time algorithm for 3-Hitting Set, which is efficient for small values of k, this being a typical occurrence when carried out in practice. (orig.)SIGLEAvailable from TIB Hannover: RR 4367(99-18) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman
How powerful is unconditional transfer? -When UT meets AC.-
We prove that every recursively enumerable language can be generated by a programmed grammar with context-free core rules using unconditional transfer with leftmost derivation of type 3 or type 2. We show that every recursively enumerable tally language can be generated by a programmed grammar with context-free core rules using unconditional transfer or by some k-limited ET0L system, where k element of N is arbitrary. (orig.)Available from TIB Hannover: RR 4367(97-7) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman
The complexity of obtaining solutions for problems in NP and NL
We review some of the known results about the complexity of computing solutions or proofs of membership for problems in NP. Trying to capture the complexity of this problem we consider the classes of functions FP"N"P, FP"N"P [f] (for certain bounded functions f), NPSV and FP_t_t"N"P and provide some examples of NP problems with search functions in these classes. We also consider whether NP-complete problems can have such proofs of membership and use the problem of obtaining solutions to compare the relative powers of the above function classes. Finally we consider the situation in the nondeterministic logarithmic space setting, showing how the complexity of obtaining solutions for NL sets compares with the NP case. (orig.)SIGLEAvailable from TIB Hannover: RR 4367(96-14) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman
Fortgeschrittene Konzepte der Standard Template Library (STL)
Available from TIB Hannover: RR 4367(96-18) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman
Studienplan zum Studium der Bioinformatik an der Universitaet Tuebingen fuer das Wintersemester 1999/2000
SIGLEAvailable from TIB Hannover: RR 4367(99-10) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman
Studienplan zum Studium der Informatik an der Universitaet Tuebingen fuer das Wintersemester 1998/99
Available from TIB Hannover: RR 4367(98-9) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman
How to lift a library
Generic algebraic libraries run the risk of losing efficiency compared to non-generic libraries. To solve the seeming antagonism between genericity and efficiency, we propose a technique which we call lifting. The lifting process is an abstraction process which starts with a well-known efficient algorithm and abstracts carefully from it. As lifting guarantees that fast non-generic algorithms instantiate their generic lifts, we preserve computing time. Apart from generic programming, lifting is interesting for computer algebra in conceptual and conceptional respects. (orig.)Available from TIB Hannover: RR 4367(96-7) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman
Studienplan zum Studium der Informatik an der Universitaet Tuebingen fuer das Wintersemester 2001/2002
Available from TIB Hannover: RR 4367(2001-15) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman
External memory sorting of strings: A practical approach
SIGLEAvailable from TIB Hannover: RR 4367(2000,24) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman
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