M.H.D. van Leeuwen, Bijstand in Amsterdam, ca. 1800-1850. Armenzorg als beheersings- en overlevingsstrategie

Conformal profiles in theHilhorst – van Leeuwen model

We study the critical energy and magnetization profiles for the Ising quantum chain with a marginal extended surface perturbation of the form A/y, y being the distance from the surface (Hilhorst-van Leeuwen model). For weak local couplings, A < Ac, the model displays a continuous surface transition with A-dependent exponents, whereas, for A > Ac, there is surface order at the bulk critical poin...

186-197 van Leeuwen fall 04

This major international history project succeeded because of the goodwill, commitment, and collaborative endeavor of a team of researchers drawn not only from different countries but also from different disciplines. Its immediate product is a recently published book, HISCO: Historical International Standard Classification of Occupations (van Leeuwen, Maas, and Miles 2002). The authors describe...

The Advent of Modern Medicine in Philadelphia, 1800-1850 *

The historian can quote sources to suit his own purpose. It would be easy to portray the American medicine of 1800 as essentially forward-looking and progressive, if just the right evidence were selected to support this interpretation. This was indeed the view of contemporary physicians themselves, who faced the nineteenth century confident that American science had more than caught up with tha...

Magazine voor aluMni van de universiteit van aMsterdaM

Thirty Years of Collaboration with Jan van Leeuwen: In Search of Understanding Computation

I have collaborated with Jan van Leeuwen since the beginning of the 1980s. The non-standard models of computations have been the central subject of our joint work. Among these models, we focused especially onto realistic models of supercomputers, interactive computing, hypercomputing, characterization of contemporary computing in terms of extended Turing machine paradigm, and viewing computatio...