A programming model for BSP with partitioned synchronisation

A BSP superstep is a distributed computation comprising a number of simultaneously executing processes which may generate asynchronous messages. A superstep terminates with a barrier which enforces a global synchronisation and delivers all ongoing communications. Multilevel supersteps can utilise barriers in which subsets of processes, interacting through shared memories, are locally synchronised (partitioned synchronisation). In this paper a state-based semantics, closely related to the classical sequential programming model, is derived for distributed BSP with partitioned synchronisation.

The Politics of Actually Existing Unsustainability:Human Flourishing in a Climate-Changed, Carbon-Constrained World

Going against both the naive techno-optimist of ‘greening business as usual’ and a resurgent ‘catastrophism’ within green thinking and politics, The Politics of Actually Existing Unsustainability offers an analysis of the causes of unsustainability and diminished human flourishing. The books locates the causes of unsustainability in dominant capitalist modes of production, debt-based consumer culture, the imperative for orthodox economic growth and the dominant ideology of neoclassical economics. It suggests that valuable insights into the causes of and alternatives to unsustainability can be found in a critical embracing of human vulnerability and dependency as both constitutive and ineliminable aspects of what it means to be human. The book defends resilience, the ability to ‘cope with’ rather than somehow ‘solve’ vulnerability. The book offers a trenchant critique of the dominant neoclassical economic ‘groupthink’, viewing it not as some value-neutral form of ‘expert knowledge’, but as a thoroughly ideological ‘common sense’. Outlining a green political economic alternative replacing economic growth with economic security, it argues economic growth has done its work in the minority, affluent world, which should now focus on improving human flourishing, lowering socio-economic equality and fostering solidarity as part of a new re-orientation of public policy. Complementing this, a, ‘green republicanism’ is developed as an innovative and original contribution to contemporary debates on a ‘post-growth’ economy and society. The Politics of Actually Existing Unsustainability draws widely from a range of disciplines and thinkers, from cultural critic Susan Sontag to the critical theory of the Frankfurt School, contemporary debates in green political thinking, and the latest thinking in heterodox and green economics, to produce a highly relevant, timely, and provocatively original statement on the human predicament in the twenty-first century.

Random neighbor sandpile model with constrained total energy

We propose as energy-constrained sandpile model with random neighbors. The critical behavior of the model is in the same universality class as the mean-field self-organized criticality sandpile. The critical energy E-c depends on the number of neighbors n of each site, but the various exponents do not. For n = 6, we got that E-c = 0.4545; and a self-similar structure of the energy distribution function with five major peaks is also observed. This is a natural result of system dynamics and the way the system is disturbed.

Universality and self-similarity of an energy-constrained sandpile model with random neighbors

We study an energy-constrained sandpile model with random neighbors. The critical behavior of the model is in the same universality class as the mean-field self-organized criticality sandpile. The critical energy E-c depends on the number of neighbors n for each site, but the various exponents are independent of n. A self-similar structure with n-1 major peaks is developed for the energy distribution p(E) when the system approaches its stationary state. The avalanche dynamics contributes to the major peaks appearing at E-Pk = 2k/(2n - 1) with k = 1,2,...,n-1, while the fine self-similar structure is a natural result of the way the system is disturbed. [S1063-651X(99)10307-6].