Jung Won Sonn's research aims to uncover urban and regional aspects of technological knowledge production. There is ample evidence to suggest that R&D activities have become increasingly concentrated in a small number of cities of the world in spite of the development of telecommunication networks. Jung Won Sonn and his colleagues proposes to illuminate how the increasing concentration of R&D activities shapes both a city’s physical form and its technological specialisation in the U.S. They intend to I hypothesise that: 1) The R&D activities are mainly located beyond the conventional boundaries of cities, thereby enlarging the urban functions’ physical scales; and 2) The cities are becoming more and more specialised in their technology, further making a city’s R&D activities different from those in other cities. In testing these hypotheses, I will use the patents as the proxy of R&D activities