We develop a framework for parallel computation of the optimal rough set decision reducts from data. We adapt the island model for evolutionary computing. The idea is to optimize reducts within separate populations (islands) and enable the best reducts-chromosomes to migrate among islands. Experiments show that the proposed method speeds up calculations and also provides often better quality of...

We discuss the implementation and evaluation of move-based hypergraph partitioning heuristics in the context of VLSI design applications. Our rst contribution is a detailed software architecture, consisting of seven reusable components, that allows exible, e cient and accurate assessment of the practical implications of new move-based algorithms and partitioning formulations. Our second contrib...

The network community structure detection problem has been recently approached with several variants of an extremal optimization algorithm. An extremal optimization algorithm is a stochastic local search method that evolves pairs of individuals that can be represented as having several components by randomly replacing components having worst fitnesses. The number of components to be replaced in...

Grayscale skeletonization offers an interesting alternative to traditional skeletonization following a binarization. It is well known that parallel algorithms for skeletonization outperform sequential ones in terms of quality of results, yet no general and well defined framework has been proposed until now for parallel grayscale thinning. We introduce in this paper a parallel thinning algorithm...

We introduce a new method for fast texture synthesis on surfaces from examples. We generalize the image-based jump map texture synthesis algorithm, which partitions the task of texture synthesis into a slower analysis phase and a fast synthesis phase, by developing a new synthesis phase which works directly on arbitrary surfaces. Our method is one to two orders of magnitude faster than existing...

PURPOSE Collaboration between specialists is essential for achieving high-value care in patients with complex cancer needs. We explore how collaboration between oncologists and surgeons affects mortality and cost for patients requiring multispecialty cancer care. PATIENTS AND METHODS This was a retrospective cohort study of patients with stage III colon cancer from SEER-Medicare diagnosed bet...

The Baire metric induces an ultrametric on a dataset and is of linear computational complexity, contrasted with the standard quadratic time agglomerative hierarchical clustering algorithm. In this work we evaluate empirically this new approach to hierarchical clustering. We compare hierarchical clustering based on the Baire metric with (i) agglomerative hierarchical clustering, in terms of algo...

The optimization is essential for any high-performance querying system. Several optimization techniques were developed and successfully implemented for relational databases. However, these techniques should be re-examined and revised for distributed heterogeneous systems of information resources supporting diverse querying paradigms. We introduce cost models for approximate query evaluation in ...

Information retrieval systems are often evaluated through the use of effectiveness metrics. In the past, the metrics used have corresponded to fixed models of user behavior, presuming, for example, that the user will view a predetermined number of items in the search engine results page, or that they have a constant probability of advancing from one item in the result page to the next. Recently...

The Ciclovia program (CP) has emerged as an effective initiative to promote active living in urban spaces in Latin America. This study assessed the association between social conditions, the urban environment and participation in the CP among adults living in the city of Cali, Colombia. A cross-sectional study was conducted in 2011 and 2012 among 719 adults aged 18 to 44. Urban environment meas...