Political Economy : Variability and Consistency in the Development of Worker Owned Cooperatives

The relationship between worker cooperatives and their social and economic environment has sparked interest among the sociological community for the contradictions and harmony typical of these interactions. However, these studies do not examine how firm behavior varies and/or remains constant in different social conditions. With insights from economic sociology, neo-institutionalism, and social movements theory, the paper pursues this issue by answering the following question: how do worker cooperatives respond to different social conditions over time? Using interviews with members of eight worker cooperatives in a Midwestern metropolitan area, the author compares behavior in older and younger cooperatives to observe similarities and differences in their practices under different social conditions. The analysis demonstrates that differences in social support and market competition created variation among older and newer cooperatives. For instance, the decision to start worker-owned cooperatives reflected different political motivations that emerged from distinct socio-economic conditions. However, all firms eventually behaved like businesses because they framed economic activities as political activism, exposing them to fluctuations in the city’s political scene. As a result, these businesses created market niches, attract customers and competent workers, and copy other successful democratic enterprises to survive demographic fluctuations in the market

Bose-Einstein Final State Symmetrization for Event Generators of Heavy Ion Collisions

We discuss algorithms which allow to calculate identical two-particle correlations from numerical simulations of relativistic heavy ion collisions. A toy model is used to illustrate their properties.Comment: Talk given at CRIS'98 (Catania, June 8-12, 1998), to appear in "CRIS'98: Measuring the size of things in the Universe: HBT interferometry and heavy ion physics", (S. Costa et al., eds.), World Scientific, Singapore, 1998. (10 pages Latex, 1 eps-figure, extended version of conference proceedings, Fig1 a,b added and corresponding discussion enlarged

Decay-assisted collinear resonance ionization spectroscopy: Application to neutron-deficient francium

This paper reports on the hyperfine-structure and radioactive-decay studies of the neutron-deficient francium isotopes $^{202-206}$Fr performed with the Collinear Resonance Ionization Spectroscopy (CRIS) experiment at the ISOLDE facility, CERN. The high resolution innate to collinear laser spectroscopy is combined with the high efficiency of ion detection to provide a highly-sensitive technique to probe the hyperfine structure of exotic isotopes. The technique of decay-assisted laser spectroscopy is presented, whereby the isomeric ion beam is deflected to a decay spectroscopy station for alpha-decay tagging of the hyperfine components. Here, we present the first hyperfine-structure measurements of the neutron-deficient francium isotopes $^{202-206}$Fr, in addition to the identification of the low-lying states of $^{202,204}$Fr performed at the CRIS experiment.Comment: Accepted for publication with Physical Review

Fourier Based Fast Multipole Method for the Helmholtz Equation

The fast multipole method (FMM) has had great success in reducing the computational complexity of solving the boundary integral form of the Helmholtz equation. We present a formulation of the Helmholtz FMM that uses Fourier basis functions rather than spherical harmonics. By modifying the transfer function in the precomputation stage of the FMM, time-critical stages of the algorithm are accelerated by causing the interpolation operators to become straightforward applications of fast Fourier transforms, retaining the diagonality of the transfer function, and providing a simplified error analysis. Using Fourier analysis, constructive algorithms are derived to a priori determine an integration quadrature for a given error tolerance. Sharp error bounds are derived and verified numerically. Various optimizations are considered to reduce the number of quadrature points and reduce the cost of computing the transfer function.Comment: 24 pages, 13 figure

The derived Picard group of an affine Azumaya algebra

We describe the derived Picard group of an Azumaya algebra A on an affine scheme X in terms of global sections of the constant sheaf of integers on X, the Picard group of X, and the stabilizer of the Brauer class of A under the action of Aut(X). In particular, we find that the derived Picard group of an Azumaya algebra is generally not isomorphic to that of the underlying scheme. In the case of the trivial Azumaya algebra, our result refines Yekutieli's description of the derived Picard group of a commutative algebra. We also get, as a corollary, an alternate proof of a result of Antieau which relates derived equivalences to Brauer equivalences for affine Azumaya algebras. The example of a Weyl algebra in finite characteristic is examined in some detail.Comment: 19 pages, updated presentatio