<> "The repository administrator has not yet configured an RDF license."^^ . <> . . . "Scale-free models for the structure of business firm networks"^^ . "We study firm collaborations in the life sciences and the information and communication technology sectors. We propose an approach to characterize industrial leadership using k-shell decomposition, with top-ranking firms in terms of market value in higher k-shell layers. We find that the life sciences industry network consists of three distinct components: a “nucleus,” which is a small well-connected subgraph, “tendrils,” which are small subgraphs consisting of small degree nodes connected exclusively to the nucleus, and a “bulk body,” which consists of the majority of nodes. Industrial leaders, i.e., the largest companies in terms of market value, are in the highest k-shells of both networks. The nucleus of the life sciences sector is very stable: once a firm enters the nucleus, it is likely to stay there for a long time. At the same time we do not observe the above three components in the information and communication technology sector. We also conduct a systematic study of these three components in random scale-free networks. Our results suggest that the sizes of the nucleus and the tendrils in scale-free networks decrease as the exponent of the power-law degree distribution λ increases, and disappear for λ≥3. We compare the k-shell structure of random scale-free model networks with two real-world business firm networks in the life sciences and in the information and communication technology sectors. We argue that the observed behavior of the k-shell structure in the two industries is consistent with the coexistence of both preferential and random agreements in the evolution of industrial networks."^^ . "2010-03" . . "81" . "3" . . "American Physical Society"^^ . . . "Physical Review E"^^ . . . "15393755" . . . . . . . . . . . . . . . . . . . "Shlomo"^^ . "Havlin"^^ . "Shlomo Havlin"^^ . . "Massimo"^^ . "Riccaboni"^^ . "Massimo Riccaboni"^^ . . "Maksim"^^ . "Kitsak"^^ . "Maksim Kitsak"^^ . . "H. Eugene"^^ . "Stanley"^^ . "H. Eugene Stanley"^^ . . "Fabio"^^ . "Pammolli"^^ . "Fabio Pammolli"^^ . . . . . . "Scale-free models for the structure of business firm networks (PDF)"^^ . . . . . "PhysRevE.Pammolli_Riccaboni_2010.pdf"^^ . . . "Scale-free models for the structure of business firm networks (Other)"^^ . . . . . . "lightbox.jpg"^^ . . . "Scale-free models for the structure of business firm networks (Other)"^^ . . . . . . "preview.jpg"^^ . . . "Scale-free models for the structure of business firm networks (Other)"^^ . . . . . . "medium.jpg"^^ . . . "Scale-free models for the structure of business firm networks (Other)"^^ . . . . . . "small.jpg"^^ . . "HTML Summary of #634 \n\nScale-free models for the structure of business firm networks\n\n" . "text/html" . . . "HB Economic Theory"@en . . . "QC Physics"@en . .