The discrete dynamics of small-scale spatial events: agent-based models of mobility in carnivals and street parades

Small-scale spatial events are situations in which elements or objects vary in such away that temporal dynamics is intrinsic to their representation and explanation. Someof the clearest examples involve local movement from conventional traffic modelingto disaster evacuation where congestion, crowding, panic, and related safety issue arekey features of such events. We propose that such events can be simulated using newvariants of pedestrian model, which embody ideas about how behavior emerges fromthe accumulated interactions between small-scale objects. We present a model inwhich the event space is first explored by agents using ?swarm intelligence?. Armedwith information about the space, agents then move in an unobstructed fashion to theevent. Congestion and problems over safety are then resolved through introducingcontrols in an iterative fashion and rerunning the model until a ?safe solution? isreached. The model has been developed to simulate the effect of changing the route ofthe Notting Hill Carnival, an annual event held in west central London over 2 days inAugust each year. One of the key issues in using such simulation is how the processof modeling interacts with those who manage and control the event. As such, thischanges the nature of the modeling problem from one where control and optimizationis external to the model to one where this is intrinsic to the simulation

Pedestrian demand modelling of large cities: an applied example from London

This paper introduces a methodology for the development of city wide pedestrian demand models and shows its application to London. The approach used for modelling is Multiple Regression Analysis of independent variables against the dependent variable of observed pedestrian flows. The test samples were from manual observation studies of average total pedestrian flow per hour on 237 sample sites. The model will provide predicted flow values for all 7,526 street segments in the 25 square kilometres of Central London. It has been independently validated by Transport for London and is being tested against further observation data. The longer term aim is to extend the model to the entire greater London area and to incorporate additional policy levers for use as a transport planning and evaluation tool

The relationship between urban street configuration and office rent patterns in Berlin

This thesis presents a study of the influence of urban street configuration on the pattern of commercial office rents in Berlin. The hypothesis is that there is a relationship between the two, and that the alteration of the street network with reunification has precipitated a spatial reorganisation of office rents. The identification of an independent spatial variable that can be used to account for the pattern of rent is a key problem in office rent studies. Unlike previously used distances to a point in the Central Business District (CBD) or other destinations, this study uses 'space syntax' measures of the morphology of the street network. 'Global integration' is used to measure the role of each street within the entire configuration, revealing fundamental changes in the spatial structure of Berlin both with the city's historical development and with reunification. Whereas most previous office rent studies have used yearly average asking rents per building for a short period, a sample of 412 achieved rents over a 7 year period was collected to control for the influence of lease provisions and the effect of market change over time on rents. The spatial pattern of 'location rents' is investigated through visual representations using GIS. Significant variation from street to street and a marked rise from periphery to centre are found. Unlike previous studies, spatial changes over time were investigated: a marked shift in the pattern of rents from West Berlin to the East has occurred in the 7 years following reunification. This shift corresponds to the changing spatial structure of the city revealed in the spatial analysis. Multiple Regression Analysis (MRA) is used to quantify the importance of spatial variables (space syntax measures) in rent determination but also taking non-spatial variables (time, building quality, and lease provisions) into account. The main findings are that rents in West Berlin can be explained by the date of lease commencement (falling with the recession) and the global spatial integration as it was in divided Berlin. In East Berlin the global integration pattern of reunfied Berlin is most important and secondly the date of lease commencement. Other variables such as floorspace and lease length are not found to have statistical significance. It is concluded that the change in Berlin's spatial structure that occurred with reunification led to a spatial reorganisation of prime office rents from the West Berlin CBD into the former East Berlin district of Mitte. It is argued that 'location value' will be an emergent property of any spatial system because a differentiated potential for co-presence is created

The Network Analysis of Urban Streets: A Primal Approach

The network metaphor in the analysis of urban and territorial cases has a long tradition especially in transportation/land-use planning and economic geography. More recently, urban design has brought its contribution by means of the "space syntax" methodology. All these approaches, though under different terms like accessibility, proximity, integration,connectivity, cost or effort, focus on the idea that some places (or streets) are more important than others because they are more central. The study of centrality in complex systems,however, originated in other scientific areas, namely in structural sociology, well before its use in urban studies; moreover, as a structural property of the system, centrality has never been extensively investigated metrically in geographic networks as it has been topologically in a wide range of other relational networks like social, biological or technological. After two previous works on some structural properties of the dual and primal graph representations of urban street networks (Porta et al. cond-mat/0411241; Crucitti et al. physics/0504163), in this paper we provide an in-depth investigation of centrality in the primal approach as compared to the dual one, with a special focus on potentials for urban design.Comment: 19 page, 4 figures. Paper related to the paper "The Network Analysis of Urban Streets: A Dual Approach" cond-mat/041124

Technological acquisitions:The impact of geography on post-acquisition innovative performance

Contains fulltext : 160470.pdf (publisher's version ) (Closed access)Our empirical study considers the impact of geography on post-acquisition performance for technological acquisitions. Relying on insights from the transaction costs and international business literatures we suggest that both geographic distance and borders influence post-acquisition innovative performance. Examining the patent portfolios of 3683 high tech acquirers in the period 2000–2012 we support a ‘liability of distance’ hypothesis and show that every 1000 km between the target and the acquirer costs as much as 19 lost patent applications. We do not find support for a ‘liability of foreignness’ hypothesis, however, but show in fact, that else equal, cross-border deals result in 3.15 additional patent applications. For high tech acquirers we find that ‘foreignness’ appears, therefore, to be more of an ‘asset’ than a ‘liability’. We find that the lion’s share of this is attributable to cultural differences

The space of innovation: interaction and communication in the work environment

As the pace of organisational change accelerates and as new technologies demand more rapid responses from organisations to changing conditions in their business environment, buildings are being called on to play an active role in helping to generate new organisational structures and in facilitating individual communication. This raises questions not only of the nature of organisational structure and of how communication technologies will affect that, but also of the possible mechanisms by which spatial structure can affect patterns of interaction in the work organisation. In this paper we will review two recent research-led design projects in which space syntax techniques were used to help define the building brief for an organisation which depends for its market lead on its ability to innovate. Building on research into the design of research laboratories, we found that patterns of space use and movement generated by spatial configuration have a direct impact on the frequency of contact between workers in office-based organisations. The frequency of contact is shown in turn to have an impact on work-related communications cited as 'useful' by questionnaire. These patterns are found to be 'system effects' in that they cannot be attributed to an individual worker's desk location but appear to result from the configuration of the whole system of spaces through which people move in their daily work, and have detectable effects on the mean 'usefulness' to others of all workers in a part of a building. The analysis suggests, however, that spatial integration alone may be insufficient to support flexible working and that spatial differentiation is necessary to provide the range of environments needed by different types of work activity.