Keywords: Pagerank * Patents * Trend Recognition * Damping Factor Recognition of Emerging Technology Trends. Class-selective Study of Citations in the U.s. Patent Citation Network

By adopting a citation-based recursive ranking method for patents the evolution of new fields of technology can be traced. Specifically, it is demonstrated that the laser / inkjet printer technology emerged from the recombination of two existing technologies: sequential printing and static image production. The dynamics of the citations coming from the different "precursor" classes illuminates the mechanism of the emergence of new fields and give the possibility to make predictions about future technological development. For the patent network the optimal value of the PageRank damping factor is close to 0.5; the application of d=0.85 leads to unacceptable ranking results. Powered by Editorial Manager® and ProduXion Manager® from Aries Systems Corporation Recognition of Emerging Technology Trends. Class-selective study of citations in the U.S. Patent Citation Network. Péter Bruck, István Réthy, Judit Szente, Jan Tobochnik and Péter Érdi a ProcessExpert Ltd, Budapest, Hungary, b Gobinfo Ltd, Budapest, Hungary, c Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, Ann Arbor, MI 48109, d Departments of Physics and Computer Science, Kalamazoo College, Kalamazoo, MI 49006, e Center for Complex Systems Studies, Kalamazoo College, Kalamazoo, MI 49006, and f Computational Neuroscience Group, Wigner Research Centre for Physics, Hungarian Academy of Sciences, Budapest Correspondence to Péter Érdi: Kalamazoo College, 1200 Academy Street, Kalamazoo, MI 49006; +1 269 337 5720; e-mail:[email protected] Abstracts By adopting a citation-based recursive ranking method for patents the evolution of new fields of technology can be traced. Specifically, it is demonstrated that the laser / inkjet printer technology emerged from the recombination of two existing technologies: sequential printing and static image production. The dynamics of the citations coming from the different ”precursor” classes illuminates the mechanism of the emergence of new fields and give the possibility to make predictions about future technological development. For the patent network the optimal value of the PageRank damping factor is close to 0.5; the application of d=0.85 leads to unacceptable ranking results.s By adopting a citation-based recursive ranking method for patents the evolution of new fields of technology can be traced. Specifically, it is demonstrated that the laser / inkjet printer technology emerged from the recombination of two existing technologies: sequential printing and static image production. The dynamics of the citations coming from the different ”precursor” classes illuminates the mechanism of the emergence of new fields and give the possibility to make predictions about future technological development. For the patent network the optimal value of the PageRank damping factor is close to 0.5; the application of d=0.85 leads to unacceptable ranking results.