Network geography: relations, interactions, scaling and spatial processes in GIS

This chapter argues that the representational basis of GIS largely avoidseven the most rudimentary distortions of Euclidean space as reflected, forexample, in the notion of the network. Processes acting on networks whichinvolve both short and longer term dynamics are often absent from GIscience. However a sea change is taking place in the way we view thegeography of natural and man-made systems. This is emphasising theirdynamics and the way they evolve from the bottom up, with networks anessential constituent of this decentralized paradigm. Here we will sketchthese developments, showing how ideas about graphs in terms of the waythey evolve as connected, self-organised structures reflected in theirscaling, are generating new and important views of geographical space.We argue that GI science must respond to such developments and needs tofind new forms of representation which enable both theory andapplications through software to be extended to embrace this new scienceof networks

Reaction time and incident cancer: 25 years of follow-up of study members in the UK Health and Lifestyle Survey

<b>Objectives</b><p></p> To investigate the association of reaction time with cancer incidence.<p></p> <b>Methods</b><p></p> 6900 individuals aged 18 to 94 years who participated in the UK Health and Lifestyle Survey in 1984/1985 and were followed for a cancer registration for 25 years.<p></p> <b>Results</b><p></p> Disease surveillance gave rise to 1015 cancer events from all sites. In general, there was essentially no clear pattern of association for either simple or choice reaction time with cancer of all sites combined, nor specific malignancies. However, selected associations were found for lung cancer, colorectal cancer and skin cancer.<p></p> <b>Conclusions</b><p></p> In the present study, reaction time and its components were not generally related to cancer risk

Planning Support Systems: Progress, Predictions, and Speculations on the Shape of Things to Come

In this paper, we review the brief history of planning support systems, sketching the way both the fields of planning and the software that supports and informs various planning tasks have fragmented and diversified. This is due to many forces which range from changing conceptions of what planning is for and who should be involved, to the rapid dissemination of computers and their software, set against the general quest to build ever more generalized software products applicable to as many activities as possible. We identify two main drivers – the move to visualization which dominates our very interaction with the computer and the move to disseminate and share software data and ideas across the web. We attempt a brief and somewhat unsatisfactory classification of tools for PSS in terms of the planning process and the software that has evolved, but this does serve to point up the state-ofthe- art and to focus our attention on the near and medium term future. We illustrate many of these issues with three exemplars: first a land usetransportation model (LUTM) as part of a concern for climate change, second a visualization of cities in their third dimension which is driving an interest in what places look like and in London, a concern for high buildings, and finally various web-based services we are developing to share spatial data which in turn suggests ways in which stakeholders can begin to define urban issues collaboratively. All these are elements in the larger scheme of things – in the development of online collaboratories for planning support. Our review far from comprehensive and our examples are simply indicative, not definitive. We conclude with some brief suggestions for the future

Hierarchies in cities and city systems

Hierarchy is implicit in the very term city. Cities grow from hamlets andvillages into small towns and thence into larger forms such as ?metropolis?,?megalopolis? and world cities which are ?gigalopolis?. In one sense, allurban agglomerations are referred to generically as cities but this sequenceof city size from the smallest identifiable urban units to the largest containsan implicit hierarchy in which there are many more smaller cities thanlarger ones. This organisation approximately scales in a regular but simplemanner, city sizes following a rank-size rule whose explanation is bothmysterious and obvious. In this chapter, we begin with a simple but wellknownmodel of urban growth where growth is randomly proportionate tocity size and where it is increasingly unlikely that a small city becomesvery big. It is easy to show that this process generates a hierarchy which isstatistically self-similar, hence fractal but this does not contain anyeconomic interactions that we know must be present in the way cities growand compete. We thus modify the model adding mild diffusion and thennote how these ideas can be fashioned using network models whichgenerate outcomes consistent with these kinds of order and scaling. Wethen turn this argument on its head and describe how the same sorts ofmorphology can be explained using ideas from central place theory. Thesenotions are intrinsic to the way cities evolve and we conclude by notinghow city design must take account of natural hierarchies which groworganically, rather than being established using top-down, centralizedplanning

Big data, smart cities and city planning

I define big data with respect to its size but pay particular attention to the fact that the data I am referring to is urban data, that is, data for cities that are invariably tagged to space and time. I argue that this sort of data are largely being streamed from sensors, and this represents a sea change in the kinds of data that we have about what happens where and when in cities. I describe how the growth of big data is shifting the emphasis from longer term strategic planning to short-term thinking about how cities function and can be managed, although with the possibility that over much longer periods of time, this kind of big data will become a source for information about every time horizon. By way of conclusion, I illustrate the need for new theory and analysis with respect to 6 months of smart travel card data of individual trips on Greater London’s public transport systems

A new theory of space syntax

Relations between different components of urban structure are often measured in aliteral manner, along streets for example, the usual representation being routesbetween junctions which form the nodes of an equivalent planar graph. A popularvariant on this theme ? space syntax ? treats these routes as streets containing one ormore junctions, with the equivalent graph representation being more abstract, basedon relations between the streets which themselves are treated as nodes. In this paper,we articulate space syntax as a specific case of relations between any two sets, in thiscase, streets and their junctions, from which we derive two related representations.The first or primal problem is traditional space syntax based on relations betweenstreets through their junctions; the second or dual problem is the more usualmorphological representation of relations between junctions through their streets.The unifying framework that we propose suggests we shift our focus from the primalproblem where accessibility or distance is associated with lines or streets, to the dualproblem where accessibility is associated with points or junctions. This traditionalrepresentation of accessibility between points rather than between lines is easier tounderstand and makes more sense visually. Our unifying framework enables us toeasily shift from the primal problem to the dual and back, thus providing a muchricher interpretation of the syntax. We develop an appropriate algebra which providesa clearer approach to connectivity and distance in the equivalent graphrepresentations, and we then demonstrate these variants for the primal and dualproblems in one of the first space syntax street network examples, the French villageof Gassin. An immediate consequence of our analysis is that we show how the directconnectivity of streets (or junctions) to one another is highly correlated with thedistance measures used. This suggests that a simplified form of syntax can beoperationalized through counts of streets and junctions in the original street network

Complexity in city systems: Understanding, evolution, and design

6.4 Exemplars of complex systems There are many signatures of complexity revealed in the space-time patterning of cities (Batty, 2005) and here we will indicate three rather different but nevertheless linked exemplars. Our first deals with ..

The emergence of cities: complexity and urban dynamics

This paper presents an approach to urban dynamics that generalizes the traditionalrank-size model first popularized by Zipf (1949). It argues that we need to define the rate atwhich new cities emerge and old cities disappear within the apparent macro stability posed byZipf?s Law. We illustrate this with a reworking and extension of Zipf?s analysis of the USurban system, taking his analysis from 1790 to 1930 forward to the year 2000. In doing so, weintroduce a variety of devices to detect urban change based on traces through the rank-sizephase space, trajectories using a rank-time clock, and the definition of urban half-lives. We setthis analysis within the wider context of stochastic simulation that is currently dominatingdiscussion of scaling processes such as these

Online participation: the Woodberry Down experiment

The internet and world wide web are generating radical changes in the way we are able tocommunicate. Our ability to engage communities and individuals in designing theirenvironment is also beginning to change as new digital media provide ways in whichindividuals and groups can interact with planners and politicians in exploring their future.This paper tells the story of how the residents of one of the most disadvantagedcommunities in Britain ? the Woodberry Down Estate in the London borough ofHackney ? have begun to use an online system which delivers everything from routineservices about their housing to ideas about options for their future. Woodberry Down isone of the biggest regeneration projects in Western Europe. It will take at least 10 years,probably much longer, to complete, at a cost of over £150 million. Online participation isone of the many ways in which this community is being engaged but as we will show, itis beginning to act as a catalyst. The kinds of networks which are evolving aroundsystems like these will change the nature of participation itself, the ways we need to thinkabout it, and the ways we need to respond. Before the experiment is described, we set thecontext by describing the wide range of digital media for communicating plans andplanning which suggests a new typology for web participation consistent with this fastemerging network culture