Displaying 21 – 40 of 181

Showing per page

Efficient generation of 3D surfel maps using RGB-D sensors

Artur Wilkowski, Tomasz Kornuta, Maciej Stefańczyk, Włodzimierz Kasprzak (2016)

International Journal of Applied Mathematics and Computer Science

The article focuses on the problem of building dense 3D occupancy maps using commercial RGB-D sensors and the SLAM approach. In particular, it addresses the problem of 3D map representations, which must be able both to store millions of points and to offer efficient update mechanisms. The proposed solution consists of two such key elements, visual odometry and surfel-based mapping, but it contains substantial improvements: storing the surfel maps in octree form and utilizing a frustum culling-based...

Efficient simulation of synchronous systems by multi-speed systems

Tomasz Jurdziński, Mirosław Kutyłowski, Jan Zatopiański (2005)

RAIRO - Theoretical Informatics and Applications - Informatique Théorique et Applications

We consider systems consisting of finite automata communicating by exchanging messages and working on the same read-only data. We investigate the situation in which the automata work with constant but different speeds. We assume furthermore that the automata are not aware of the speeds and they cannot measure them directly. Nevertheless, the automata have to compute a correct output. We call this model multi-speed systems of finite automata. Complexity measure that we consider here is the number...

Efficient simulation of synchronous systems by multi-speed systems

Tomasz Jurdziński, Mirosław Kutyłowski, Jan Zatopiański (2010)

RAIRO - Theoretical Informatics and Applications

We consider systems consisting of finite automata communicating by exchanging messages and working on the same read-only data. We investigate the situation in which the automata work with constant but different speeds. We assume furthermore that the automata are not aware of the speeds and they cannot measure them directly. Nevertheless, the automata have to compute a correct output. We call this model multi-speed systems of finite automata. Complexity measure that we consider here is the...

Efficient validation and construction of border arrays and validation of string matching automata

Jean-Pierre Duval, Thierry Lecroq, Arnaud Lefebvre (2009)

RAIRO - Theoretical Informatics and Applications - Informatique Théorique et Applications

We present an on-line linear time and space algorithm to check if an integer array f is the border array of at least one string w built on a bounded or unbounded size alphabet Σ . First of all, we show a bijection between the border array of a string w and the skeleton of the DFA recognizing Σ * w , called a string matching automaton (SMA). Different strings can have the same border array but the originality of the presented method is that the correspondence between a border array and a skeleton of SMA...

Efficient validation and construction of border arrays and validation of string matching automata

Jean-Pierre Duval, Thierry Lecroq, Arnaud Lefebvre (2008)

RAIRO - Theoretical Informatics and Applications

We present an on-line linear time and space algorithm to check if an integer array f is the border array of at least one string w built on a bounded or unbounded size alphabet Σ. First of all, we show a bijection between the border array of a string w and the skeleton of the DFA recognizing Σ*ω, called a string matching automaton (SMA). Different strings can have the same border array but the originality of the presented method is that the correspondence between a border array and a...

Efficient weighted expressions conversion

Faissal Ouardi, Djelloul Ziadi (2008)

RAIRO - Theoretical Informatics and Applications - Informatique Théorique et Applications

J. Hromkovic et al. have given an elegant method to convert a regular expression of size n into an ε -free nondeterministic finite automaton having O ( n ) states and O ( n log 2 ( n ) ) transitions. This method has been implemented efficiently in O ( n log 2 ( n ) ) time by C. Hagenah and A. Muscholl. In this paper we extend this method to weighted regular expressions and we show that it can be achieved in O ( n log 2 ( n ) ) time.

Efficient weighted expressions conversion

Faissal Ouardi, Djelloul Ziadi (2007)

RAIRO - Theoretical Informatics and Applications

J. Hromkovic et al. have given an elegant method to convert a regular expression of size n into an ε-free nondeterministic finite automaton having O(n) states and O(nlog2(n)) transitions. This method has been implemented efficiently in O(nlog2(n)) time by C. Hagenah and A. Muscholl. In this paper we extend this method to weighted regular expressions and we show that it can be achieved in O(nlog2(n)) time.

Egipsys: An enhanced gene expression programming approach for symbolic regression problems

Heitor Lopes, Wagner Weinert (2004)

International Journal of Applied Mathematics and Computer Science

This paper reports a system based on the recently proposed evolutionary paradigm of gene expression programming (GEP). This enhanced system, called EGIPSYS, has features specially suited to deal with symbolic regression problems. Amongst the new features implemented in EGIPSYS are: new selection methods, chromosomes of variable length, a new approach to manipulating constants, new genetic operators and an adaptable fitness function. All the proposed improvements were tested separately, and proved...

Currently displaying 21 – 40 of 181