17 research outputs found

    Interactions In Space For Archaeological Models

    Full text link
    In this article we examine a variety of quantitative models for describing archaeological networks, with particular emphasis on the maritime networks of the Aegean Middle Bronze Age. In particular, we discriminate between those gravitational networks that are most likely (maximum entropy) and most efficient (best cost/benefit outcomes).Comment: 21 pages, 6 figures, 2 tables. Contribution to special issue of Advances in Complex Systems from the conference `Cultural Evolution in Spatially Structured Populations', UCL, London, September 2010. To appear in Advances in Complex System

    Delineation of the Path Dependence in Development of Central Business Districts (CBD) in Turkey's Kayseri

    Get PDF
    This article examines the demolition-oriented restructuring relationship during urban development processes in the case study of the central business district in Kayseri (Turkey) by systematically analysing externally-conditioned events and trajectories. This transformation, characterised by changing periods of development and the analysis of the actors who are particularly active in the process, is explored through the socio-spatial developments in Kayseri. In this study, this has been expounded through the concept of path dependence, which states that current conditions are more dependent on past events and those past events lead to today's results. The decisions on the historically contingent periods and three critical junctures identified in the study were found to have been maintained until the next stage and strengthened by following the path-dependent tendency

    Using the State Space of a BLV Retail Model to Analyse the Dynamics and Categorise Phase Transitions of Urban Development

    Get PDF
    Urban areas are now the dominant human habitat, with more influence than ever on economies, environment and our health. Dynamic urban models are increasingly applied to explore possible future scenarios of urban development to achieve sustainability. However, it is still challenging to use these models for prediction, taking into consideration the complex nature of urban systems, the nonlinear interactions between different parts of the system, and the large quantities of data output from simulations. The aim of this study is to analyse the dynamics of two hypothetical dynamic BLV (Boltzmann-Lotka-Volterra) retail models (2-zone and 3-zone). Here, by visualising and analysing the qualitative nature of state space (the space of all possible initial conditions), we propose an alternative way of understanding urban dynamics more fully. This involves examining all possible configurations of an urban system in order to identify the potential development in future. Using this method we are able to identify a supply-demand balancing hyperplane and identify two causes of phase transition of urban development: 1) change in variable values (e.g. building a new shopping centre) that cause the system to cross a basin boundary, 2) state space change (e.g. construction of a new motorway changes travel costs in the region) causes the containing basin to be modified. We also identify key characteristics of the dynamics such as velocity and how the phase space landscape changes over time. This analysis is then linked with equilibrium-size graphs, which allow insights from state space to be applicable to models with large numbers of zones. More generally this type of analysis can potentially offer insights into the nature of the dynamics in any dynamical-systems-type urban model. This is critical for increasing our understanding and helping stakeholders and policy-makers to plan for future urban changes

    Harris and Wilson (1978) Model Revisited: The Spatial Period-doubling Cascade in an Urban Retail Model

    Get PDF
    Harris and Wilson (1978)’s retail location model is one of the pioneering works in regional sciences on the combination of the “fast” and “slow” dynamic describing spatial pattern formation processes in the economic landscape, which is a current well-established modeling technique. Although proposed some time ago, the comparative static (bifurcation) properties of the model have not yet been sufficiently explored. We employ a simple analytical approach developed by Akamatsu et al. (2012) to reveal previously unknown bifurcation properties of the model in a space with a large number of locations. It is analytically shown that the evolutionary path of spatial structure exhibits a remarkable property, namely “spatial period- doubling cascade,” which we cannot observe in the popular two-location setup. We also discuss strong linkages between the model and the models of “new economic geography” regarding the modeling strategies and their bifurcation properties

    Harris and Wilson (1978) Model Revisited: The Spatial Period-doubling Cascade in an Urban Retail Model

    Get PDF
    Harris and Wilson (1978)’s retail location model is one of the pioneering works in regional sciences. This model considers the combination of the “fast” and “slow” dynamics to describe spontaneous spatial pattern formation processes in the economic landscape. Although the model was proposed some time ago, its comparative static (bifurcation) properties have not yet been sufficiently explored. We employ a simple analytical approach developed by Akamatsu et al. (2012) to reveal previously unknown bifurcation properties of the model in a space with a large number of locations. It is analytically shown that the spatial structure’s evolutionary path exhibits a remarkable property, namely a “spatial period-doubling cascade,” which cannot be observed in the popular two-location setup. Furthermore, we discuss strong linkages between the model and “new economic geography” models in terms of their model structures and bifurcation properties. These results offer a new theoretical perspective for understanding agglomeration and spatial structure evolution

    Being Interdisciplinary: Adventures in urban science and beyond

    Get PDF
    In Being Interdisciplinary, Alan Wilson draws on five decades as a leading figure in urban science to set out a systems approach to interdisciplinarity for those conducting research in this and other fields. He argues that most research is interdisciplinary at base, and that a systems perspective is particularly appropriate for collaboration because it fosters an outlook that sees beyond disciplines. There is a more subtle thread, too. A systems approach enables researchers to identify the game-changers of the past as a basis for thinking outside convention, for learning how to do something new and how to be ambitious, in a nutshell how to be creative. Ultimately, the ideas presented address how to do research. Building on this systems focus, the book first establishes the basics of interdisciplinarity. Then, by drawing on the author’s experience of doing interdisciplinary research, and working from his personal toolkit, it offers general principles and a framework from which researchers can build their own interdisciplinary toolkit, with elements ranging from explorations of game-changers in research to superconcepts. In the last section, the book tackles questions of managing and organising research from individual to institutional scales. Alan Wilson deploys his wide experience – researcher in urban science, university professor and vice-chancellor, civil servant and institute director – to build the narrative. While his experience in urban science provides the illustrations, the principles apply across many research fields

    Being Interdisciplinary

    Get PDF
    In Being Interdisciplinary, Alan Wilson draws on five decades as a leading figure in urban science to set out a systems approach to interdisciplinarity for those conducting research in this and other fields. He argues that most research is interdisciplinary at base, and that a systems perspective is particularly appropriate for collaboration because it fosters an outlook that sees beyond disciplines. There is a more subtle thread, too. A systems approach enables researchers to identify the game-changers of the past as a basis for thinking outside convention, for learning how to do something new and how to be ambitious, in a nutshell how to be creative. Ultimately, the ideas presented address how to do research. Building on this systems focus, the book first establishes the basics of interdisciplinarity. Then, by drawing on the author’s experience of doing interdisciplinary research, and working from his personal toolkit, it offers general principles and a framework from which researchers can build their own interdisciplinary toolkit, with elements ranging from explorations of game-changers in research to superconcepts. In the last section, the book tackles questions of managing and organising research from individual to institutional scales. Alan Wilson deploys his wide experience – researcher in urban science, university professor and vice-chancellor, civil servant and institute director – to build the narrative. While his experience in urban science provides the illustrations, the principles apply across many research fields

    Quantifying criticality, information dynamics and thermodynamics of collective motion

    Get PDF
    Active matter consists of self-propelled particles whose interactions give rise to coherent collective motion. Well-known examples include schools of fish, flocks of birds, swarms of insects and herds of ungulates. On the micro-scale, cells, enzymes and bacteria also move collectively as active matter, inspiring engineering of artificial materials and devices. These diverse systems exhibit similar collective behaviours, including gathering, alignment and quick propagation of perturbations, which emerge from relatively simple local interactions. This phenomenon is known as self-organisation and is observed in active matter as well as in many other complex collective phenomena, including urban agglomeration, financial crises, ecosystems dynamics and technological cascading failures. Some open challenges in the study of self-organisation include (a) how the information processing across the collective and over time gives rise to emergent behaviour, (b) how to identify the regimes in which different collective behaviours exist and their phase transitions, and (c) how to quantify the thermodynamics associated with these phenomena. This thesis aims to investigate these topics in the context of active matter, while building a rigorous theoretical framework. Specifically, this thesis provides three main contributions. Firstly, the question of how to formally measure information transfer across the collective is addressed and applied to a real system, i.e., a school of fish. Secondly, general relations between statistical mechanical and thermodynamical quantities are analytically derived and applied to a model of active matter, resulting in the formulation of the concept of “thermodynamic efficiency of computation during collective motion”. This concept is then extended to the domain of urban dynamics. Thirdly, this thesis provides a rigorous quantification of the non-equilibrium entropy production associated with the collective motion of active Brownian particles
    corecore