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We describe an algorithm for the FEEDBACK VERTEX SET problem on undirected graphs, parameterized by the size k of the feedback vertex set, that runs in time O(c k n 3) where c = 10.567 and n is the number of vertices in the graph. The best previous algorithms were based on the method of bounded search trees, branching on short cycles. The best previous(More)
Fixed-parameter tractability (FPT) techniques have recently been successful in solving NP-complete problem instances of practical importance which were too large to be solved with previous methods. In this paper, we show how to enhance this approach through the addition of parallelism, thereby allowing even larger problem instances to be solved in practice.(More)
BACKGROUND Identification of protein interaction networks has received considerable attention in the post-genomic era. The currently available biochemical approaches used to detect protein-protein interactions are all time and labour intensive. Consequently there is a growing need for the development of computational tools that are capable of effectively(More)
The subtree prune and regraft distance (d(SPR)) between phylogenetic trees is important both as a general means of comparing phylogenetic tree topologies as well as a measure of lateral gene transfer (LGT). Although there has been extensive study on the computation of d(SPR) and similar metrics between rooted trees, much less is known about SPR distances(More)
In order to facilitate efficient query processing, the information contained in data warehouses is typically stored as a set of materialized views. Deciding which views to materialize represent a challenge in order to minimize view maintenance and query processing costs. Some existing approaches are applicable only for small problems, which are far from(More)
We study scalable parallel computational geometry algorithms for the coarse grained multicomputer model: p processors solving a problem on n data items, were each processor has O(n p) O(1) local memory and all processors are connected via some arbitrary interconnection network (e.g. mesh, hypercube, fat tree). We present O(Tsequential p + T s (n; p)) time(More)
In this paper, we study the cluster editing problem which is fixed parameter tractable. We present the first practical implementation of a FPT based method for cluster editing, using the approach in [6,7], and compare our implementation with the straightforward greedy method and a solution based on linear programming [3]. Our experiments show that the best(More)
In order to facilitate query processing, the information contained in data warehouses is typically stored as a set of materialized views. Deciding which views to materialize presents a considerable challenge. The task is to select from a very large search space a set of views that minimizes view maintenance and query processing costs. Heuristic methods have(More)
Parallelism pervades all aspects of modern computing, from in-home devices such as cell phones to large-scale supercomputers. Recognizing this - and motivated by the premise that every undergraduate student in a computer-related field should be prepared to cope with parallel computing - a working group sponsored by NSF and IEEE/TCPP, and interacting with(More)