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Habilitation
Computing Ground States for Fermi-Bose Mixtures through Efficient Numerical Methods
(2023-05)
In this work, we will first review the Quantum Mechanics theory to derive the main equations. Next, we will analyze these equations by Functional Analysis methods to find conditions for existence, uniqueness, multiplicity, and other properties as positivity. Next, we will review and develop some numerical methods for solving the nonlinear Schrödinger equation, its time version, generalizations with rotational terms, and systems of NLSE (NLSS). We notice that the main problem to run numerical methods is the memory ...
Dissertation
Diversity of aphyllophoroid fungi from taxonomical and biogeographical perspectives
(2018)
Comprehensive knowledge of biodiversity is a prerequisite for its long-term conservation and sustainable use. Fungi play crucial roles in ecosystems and are among the species-richest organism groups on Earth. However, all aspects of their diversity remain underexplored.
In this study, we aimed to fill the gaps in occurrence data and taxonomy as well as in understanding spatial diversity patterns of aphyllophoroid fungi (non-gilled macroscopic Basidiomycota). We digitized and made openly accessible 4,041 records of ...
Habilitation
Applicability of ordinal-array-based indicators to strange nonchaotic attractors
(Universität Kassel, 2017-06-12)
Time series are useful for modeling systems behavior, for predicting some events (catastrophes, epidemics, weather, ...) or for classification purposes (pattern recognition, pattern analysis). Among the existing data analysis algorithms, ordinal pattern based algorithms have been shown effective when dealing with simulation data. However, when applied to quasi-periodically forced systems, they fail to detect SNA and tori as regular dynamics. In this work we address this concern by defining ordinal array (OA) based ...
Dissertation
Modellbildung in der algebraischen Kryptoanalyse
(2015-04-22)
In der algebraischen Kryptoanalyse werden moderne Kryptosysteme als polynomielle, nichtlineare Gleichungssysteme dargestellt. Das Lösen solcher Gleichungssysteme ist NP-hart. Es gibt also keinen Algorithmus, der in polynomieller Zeit ein beliebiges nichtlineares Gleichungssystem löst. Dennoch kann man aus modernen Kryptosystemen Gleichungssysteme mit viel Struktur generieren. So sind diese Gleichungssysteme bei geeigneter Modellierung quadratisch und dünn besetzt, damit nicht beliebig. Dafür gibt es spezielle ...
Preprint
Degrees of Free Word-Order and Freely Rewriting Restarting Automata
(Universität Kassel, FB 17, Mathematik/Informatik, 2005)
In natural languages with a high degree of word-order freedom syntactic phenomena like dependencies (subordinations) or valencies do not depend on the word-order (or on the individual positions of the individual words). This means that some permutations of sentences of these languages are in some (important) sense syntactically equivalent. Here we study this phenomenon in a formal way. Various types of j-monotonicity for restarting automata can serve as parameters for the degree of word-order freedom and for the ...
Preprint
On the Descriptional Complexity of Simple RL-Automata
(2006)
Analysis by reduction is a method used in linguistics for checking the correctness of sentences of natural languages.
This method is modelled by restarting automata. Here we study a new type of restarting automaton, the so-called t-sRL-automaton, which is an RL-automaton that is rather restricted in that it has a window of size 1 only, and that it works under a minimal acceptance condition.
On the other hand, it is allowed to perform up to t rewrite (that is, delete) steps per cycle.
We focus on the descriptional ...
Preprint
On the Gap-Complexity of Simple RL-Automata
(2006)
Analysis by reduction is a method used in linguistics for checking the correctness of sentences of natural languages. This method is modelled by restarting automata. All types of restarting automata considered in the literature up to now accept at least the deterministic context-free languages. Here we introduce and study a new type of restarting automaton, the so-called t-RL-automaton, which is an RL-automaton that is rather restricted in that it has a window of size one only, and that it works under a minimal ...
Preprint
Restarting automata with restricted utilization of auxiliary symbols
(Universität Kassel, FB 17, Mathematik/Informatik, 2005)
The restarting automaton is a restricted model of computation that was introduced by Jancar et al. to model the so-called analysis by reduction, which is a technique used in linguistics to analyze sentences of natural languages. The most general models of restarting automata make use of auxiliary symbols in their rewrite operations, although this ability does not directly correspond to any aspect of the analysis by reduction. Here we put restrictions on the way in which restarting automata use auxiliary symbols, and ...
Preprint
Shrinking restarting automata
(Universität Kassel, FB 17, Mathematik/Informatik, 2005)
Restarting automata are a restricted model of computation that was introduced by Jancar et.al. to model the so-called analysis by reduction. A computation of a restarting automaton consists of a sequence of cycles such that in each cycle the automaton performs exactly one rewrite step, which replaces a small part of the tape content by another, even shorter word. Thus, each language accepted by a restarting automaton belongs to the complexity class $CSL cap NP$. Here we consider a natural generalization of this model, ...
Preprint
5. Krypto-Tag - Workshop über Kryptographie
(2006)
Dieser Tagungsband enthält die gesammelten Zusammenfassungen der acht eingereichten Vorträge des 5. Krypto-Tags. Der Kryptotag ist eine zentrale Aktivität der Fachgruppe "Angewandte Kryptologie" der Gesellschaft für Informatik e.V. Er ist eine wissenschaftliche Veranstaltung im Bereich der Kryptologie und von der organisatorischen Arbeit der Fachgruppe getrennt.