The Leiden Ranking 2011/2012 is a ranking of universities based on bibliometric indicators of publication output, citation impact, and scientific collaboration. The ranking includes 500 major universities from 41 different countries. This paper provides an extensive discussion of the Leiden Ranking 2011/2012. The ranking is compared with other global university rankings, in particular the Acade...

We settle the approximability of the Minimum Betweenness problem in tournaments by designing a polynomial time approximation scheme (PTAS). No constant factor approximation was previously known. We also introduce a more general class of so-called fragile ranking problems and construct PTASs for them. The results depend on a new technique of dealing with fragile ranking constraints and could be ...

The problem of rank aggregation has been studied in contexts varying from sports, to multi-criteria decision making, to machine learning, to academic citations, to ranking web pages, and to descriptive decision theory. Rank aggregation is the mapping of inputs that rank subsets of a set of objects into a consistent ranking that represents in some meaningful way the various inputs. In the rankin...

Bipartite ranking is a fundamental ranking problem that learns to order relevant instances ahead of irrelevant ones. One major approach for bipartite ranking, called the pair-wise approach, tackles an equivalent binary classification problem of whether one instance out of a pair of instances should be ranked higher than the other. Nevertheless, the number of instance pairs constructed from the ...

migration of virtual machine (vm) is a critical challenge in cloud computing. the process to move vms or applications from one physical machine (pm) to another is known as vm migration. in vm migration several issues should be considered. one of the major issues in vm migration problem is selecting an appropriate pm as a destination for a migrating vm. to face this issue, several approaches are...

This correspondence presents a novel hybrid wrapper and filter feature selection algorithm for a classification problem using a memetic framework. It incorporates a filter ranking method in the traditional genetic algorithm to improve classification performance and accelerate the search in identifying the core feature subsets. Particularly, the method adds or deletes a feature from a candidate ...