Michael Porter's Cluster Theory as a local and regional development tool – the rise and fall of cluster policy in the UK

There has been much written on industrial agglomeration, but it is Michael Porter’s cluster theory, above all others, which has come to dominate local and regional economic development policy. His work has been adopted by the OECD, EU, national and local governments the world over. He and his consultancy group have led reviews of national economic growth strategies in dozens of countries. This rise to prominence, however, is in the face of widespread critique from academics. Cluster theory’s theoretical foundations, its methodological approach and practical implementation have all been unpicked, leading some to label little more than a successful brand riding the wave of new regionalist fashions. Despite libraries of incredibly useful books and articles on clusters, there remains an absence of work which interrogates the translation of clusters into, and then through local and national policy. The aim of this article is to go some way to remedying the situation by examining the influence of Porter’s cluster theory charted through an examin- ation of UK regional development policy in the 1990s and 2000s. To help map the journey of clusters into and through UK economic development policy actor-network theory is adopted as an explanatory framework

Fix Your Types

When using existing ACL2 datatype frameworks, many theorems require type hypotheses. These hypotheses slow down the theorem prover, are tedious to write, and are easy to forget. We describe a principled approach to types that provides strong type safety and execution efficiency while avoiding type hypotheses, and we present a library that automates this approach. Using this approach, types help you catch programming errors and then get out of the way of theorem proving.Comment: In Proceedings ACL2 2015, arXiv:1509.0552

Meta-extract: Using Existing Facts in Meta-reasoning

ACL2 has long supported user-defined simplifiers, so-called metafunctions and clause processors, which are installed when corresponding rules of class :meta or :clause-processor are proved. Historically, such simplifiers could access the logical world at execution time and could call certain built-in proof tools, but one could not assume the soundness of the proof tools or the truth of any facts extracted from the world or context when proving a simplifier correct. Starting with ACL2 Version 6.0, released in December 2012, an additional capability was added which allows the correctness proofs of simplifiers to assume the correctness of some such proof tools and extracted facts. In this paper we explain this capability and give examples that demonstrate its utility.Comment: In Proceedings ACL2Workshop 2017, arXiv:1705.0076

Verified AIG Algorithms in ACL2

And-Inverter Graphs (AIGs) are a popular way to represent Boolean functions (like circuits). AIG simplification algorithms can dramatically reduce an AIG, and play an important role in modern hardware verification tools like equivalence checkers. In practice, these tricky algorithms are implemented with optimized C or C++ routines with no guarantee of correctness. Meanwhile, many interactive theorem provers can now employ SAT or SMT solvers to automatically solve finite goals, but no theorem prover makes use of these advanced, AIG-based approaches. We have developed two ways to represent AIGs within the ACL2 theorem prover. One representation, Hons-AIGs, is especially convenient to use and reason about. The other, Aignet, is the opposite; it is styled after modern AIG packages and allows for efficient algorithms. We have implemented functions for converting between these representations, random vector simulation, conversion to CNF, etc., and developed reasoning strategies for verifying these algorithms. Aside from these contributions towards verifying AIG algorithms, this work has an immediate, practical benefit for ACL2 users who are using GL to bit-blast finite ACL2 theorems: they can now optionally trust an off-the-shelf SAT solver to carry out the proof, instead of using the built-in BDD package. Looking to the future, it is a first step toward implementing verified AIG simplification algorithms that might further improve GL performance.Comment: In Proceedings ACL2 2013, arXiv:1304.712

Geographies of Skateboarding - Newcastle upon Tyne and Gateshead, UK

This map is the result of a year-long research project on the geographies of skateboarding in Newcastle upon Tyne and Gateshead, UK. Skateboarders are often seen as invaders of urban space, subverting it for their own purposes, contrary to the normative actions of others. In the capitalist system, abstract space is created in which behaviour is prescribed and dictated, often for commercial consumption practices. Borden (2001) has suggested that the act of skateboarding the city rejects this use of urban space by implicitly critiquing space and architecture as a commodity. Through the reproduction of space as a play zone, skateboarders offer no monetary exchange value for the time which they spend at a location. This frequently leads to conflict with those seeking to control urban spaces designed for capitalist consumption

The accidental youth club: skateboarding in NewcastleGateshead.

Skateboarders re-invent and interrogate the physical structure of cityscapes as they use spaces, buildings and objects for skating. However skaters are routinely regarded by the civic and business interests who dominate city centre planning and regeneration as, at best, a nuisance and at worst an unruly and dangerous blight. This paper reports findings from a research project involving skaters which begins to unpick this stereotype. A participatory methodology combining mapping, interviews and observation was used to identify spots used by skaters in Newcastle and Gateshead (North East England). The key spots were characterized using Woolley & Johns’(2001) criteria: trickability, accessibility, sociability and compatibility. Findings reveal two further 12 factors – temporal and relational dimensions – are crucial the journeys skaters embark on. Sociability was the one constant factor defining favoured spots. The study revealed a sociable, entrepreneurial, creative skate scene. Far from being a problem the skaters add to the social capital of the cityscape. Our findings suggest rather than designing out skaters from the city the civic authorities should work with skaters to sustain their scene as a positive benefit to city regeneration