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Computing Shortest, Fastest, and Foremost Journeys in Dynamic Networks
- Binh-Minh Bui-Xuan, Afonso Ferreira, A. Jarry
- Computer ScienceInt. J. Found. Comput. Sci.
- 1 April 2003
A recently proposed graph theoretic model is used and extended, which helps capture the evolving characteristic of complex communications networks, in order to propose and formally analyze least cost journey in a class of dynamic networks, where the changes in the topology can be predicted in advance.
Complexity of Connected Components in Evolving Graphs and the Computation of Multicast Trees in Dynamic Networks
This paper first shows that computing different types of strongly connected components in evolving digraphs is NP-Complete, and then proposes an algorithm to build all rooted directed minimum spanning trees in strongly connected dynamic networks.
Building a reference combinatorial model for MANETs
- Afonso Ferreira
- Computer ScienceIEEE Network
- 1 September 2004
It is shown how the modeling of time-changes unsettles old questions and allows for new insights into central problems in networking, such as routing metrics, connectivity, and spanning trees.
Efficient Parallel Graph Algorithms for Coarse-Grained Multicomputers and BSP
- F. Dehne, Afonso Ferreira, Edson Cáceres, S. W. Song, A. Roncato
- Computer ScienceAlgorithmica
- 1 June 2002
The algorithms for Problems (1)—(7) are the first practically relevant parallel algorithms for these standard graph problems, and the number of communication rounds/ supersteps obtained in this paper is independent of the problem size, and grows only logarithmically with respect to p.
Scheduling Multiprocessor Tasks with Genetic Algorithms
- Ricardo C. Corrêa, Afonso Ferreira, P. Rebreyend
- Computer ScienceIEEE Trans. Parallel Distributed Syst.
- 1 August 1999
A new combined approach, where a genetic algorithm is improved with the introduction of some knowledge about the scheduling problem represented by the use of a list heuristic in the crossover and mutation genetic operations, which shows that the knowledge-augmented algorithm produces much better results in terms of quality of solutions, although being slower interms of execution time.
Optimal information dissemination in Star and Pancake networks
- Afonso Ferreira, P. Berthomé, S. Pérennes
- Computer ScienceProceedings of 5th IEEE Symposium on Parallel…
- 2 December 1993
The paper presents a new decomposition technique for hierarchical Cayley graphs. This technique yields a very easy implementation of the divide and conquer paradigm for weak order problems on very…
The Minimum Range Assignment Problem on Linear Radio Networks
- A. Clementi, P. Penna, Afonso Ferreira, S. Pérennes, R. Silvestri
- 1 February 2003
This paper presents the first polynomial-time, approximation algorithm for the MIN ASSIGNMENT problem, which guarantees a 2-approximation ratio and runs in O(hn 3 ) time and proves that, for fixed h and for ``well spaced'' instances, the problem admits a polynometric-time approximation scheme.
Revisiting parametric multi-terminal problems: Maximum flows, minimum cuts and cut-tree computations
Efficient Parallel Graph Algorithms For Coarse Grained Multicomputers and BSP
The algorithms presented are the first practically relevant deterministic parallel algorithms for these problems to be used for commercially available coarse grained parallel machines and view as an important step towards the final goal of O(1) communication rounds.
Computing the Medial Axis Transform in Parallel With Eight Scan Operations
The main result of this paper shows that the block-based digital medial axis transform can be computed in parallel by a constant number of calls to scan (parallel prefix) operations. This gives time-…