Parallel Graph Partitioning for Complex Networks

Processing large complex networks like social networks or web graphs has recently attracted considerable interest. In order to do this in parallel, we need to partition them into pieces of about equal size. Unfortunately, previous parallel graph partitioners originally developed for more regular mesh-like networks do not work well for these networks. This paper addresses this problem by parallelizing and adapting the label propagation technique originally developed for graph clustering. By introducing size constraints, label propagation becomes applicable for both the coarsening and the refinement phase of multilevel graph partitioning. We obtain very high quality by applying a highly parallel evolutionary algorithm to the coarsened graph. The resulting system is both more scalable and achieves higher quality than state-of-the-art systems like ParMetis or PT-Scotch. For large complex networks the performance differences are very big. For example, our algorithm can partition a web graph with 3.3 billion edges in less than sixteen seconds using 512 cores of a high performance cluster while producing a high quality partition -- none of the competing systems can handle this graph on our system.Comment: Review article. Parallelization of our previous approach arXiv:1402.328

Green's Functions for Neutrino Mixing

The Green's function formalism for neutrino mixing is presented and the exact oscillation formula is obtained. The usual Pontecorvo formula is recovered in the relativistic limit.Comment: 4 pages, LaTeX (need sprocl.sty). To appear in the Proceedings of the 6th International Symposium on Particles, Strings and Cosmology (PASCOS 98), Boston, 22-27 March 199

FDI liberalization, firm heterogeneity and foreign ownership: German firm decisions in reforming India

The paper investigates the role of firm-level productivity and industry-level R&D for MNEs' choice of undertaking FDI, and the share of ownership in foreign affiliates. Two firm-specific datasets on German MNEs with varying equity stakes in Indian affiliates are used to account for the two-step decision process. The paper also analyses how German firm decisions were affected by the liberalisation of FDI regulations in India. Results show remarkable differences between the selection and the ownership share equation, and also between the pre-reform and post-reform periods. The evidence clearly reveals the tradeoffs involved in selective FDI approvals and foreign ownership restrictions. --multinational enterprises,firm characteristics,selective FDI approval,German FDI,ownership share,Heckman model