What do we need to add to a social network to get a society? answer: something like what we have to add to a spatial network to get a city

Recent years have seen great advances in social network analysis. Yet, with a few exceptions, the field of network analysis remains remote from social theory. As a result, much social network research, while technically accomplished and theoretically suggestive, is essentially descriptive. How then can social networks be linked to social theory ? Here we pose the question in its simplest form: what must we add to a social network to get a society ? We begin by showing that one reason for the disconnection between network theory and society theory is that because it exists in spacetime, the concept of social network raises the issue of space in a way that is problematical for social theory. Here we turn the problem on its head and make the problem of space in social network theory explicit by proposing a surprising analogy with the question: what do you have to add to an urban space network to get a city. We show first that by treating a city as a naïve spatial network in the first instance and allowing it to acquire two formal properties we call reflexivity and nonlocality, both mediated through a mechanism we call description retrieval, we can build a picture of the dynamics processes by which collections of the buildings become living cities. We then show that by describing societies initially as social networks in space-time and adding similar properties, we can construct a plausible ontology of a simple human society

Studying cities to learn about minds: some possible implications of space syntax for spatial cognition

What can we learn of the human mind by examining its products? The city is a case in point. Since the beginning of cities human ideas about them have been dominated by geometric ideas, and the real history of cities has always oscillated between the geometric and the ‘organic’. Set in the context of the suggestion from cognitive neuroscience that we impose more geometric order on the world than it actually possesses, and intriguing question arises: what is the role of the geometric intuition in how we understand cities and how we create them? Here I argue, drawing on space syntax research which has sought to link the detailed spatial morphology of cities to observable functional regularities, that all cities, the organic as well as the geometric, are pervasively ordered by geometric intuition, so that neither the forms of the cities nor their functioning can be understood without insight into their distinctive and pervasive emergent geometrical forms. The city is often said to be the creation of economic and social processes, but here it is argued that these processes operate within an envelope of geometric possibility defined by the human mind in its interaction with spatial laws that govern the relations between objects and spaces in the ambient world

On the Importance of the Interclump Medium for Superionization: O VI Formation in the Wind of Zeta Pup

We have studied superionization and X-ray line formation in the spectra of Zeta Pup using our new stellar atmosphere code (XCMFGEN) that can be used to simultaneously analyze optical, UV, and X-ray observations. Here, we present results on the formation of the O VI ll1032, 1038 doublet. Our simulations, supported by simple theoretical calculations, show that clumped wind models that assume void in the interclump space cannot reproduce the observed O VI profiles. However, enough O VI can be produced if the voids are filled by a low density gas. The recombination of O VI is very efficient in the dense material but in the tenuous interclump region an observable amount of O VI can be maintained. We also find that different UV resonance lines are sensitive to different density regimes in Zeta Pup : C IV is almost exclusively formed within the densest regions, while the majority of O VI resides between clumps. N V is an intermediate case, with contributions from both the tenuous gas and clumps.Comment: Accepted for publication in ApJL, 4 pages with 3 figure

Social exclusion and transportation in Peachtree City, Georgia

This paper will discuss how, in a small American city, Peachtree City (43km south of Atlanta), the flexibility and relative affordability of electric golf carts, as a viablealternative to the automobile, means that the level at which families and individuals are disadvantaged through their lack of access to public/private transport is effectively lowered. Economic access to golf carts, in of itself, would not be sufficient if it were not for the extensive, highly penetrative and 'ringy' spatial structure of the cart path system, a mostly-segregated, 150 kilometre network. A spatial analysis of this dual transportation system is presented and its implications discussed. The conclusion of this paper is that the duality of the effective spatial structure of the cart path networkand the relative low cost and inherent flexibility of the golf carts combine to reduce transportation-linked social exclusion in Peachtree City. This argument is substantiated, in the final section of the paper, through the evidence of a questionnairedistributed to a random sampling of 1,038 property owners and renters in the city

The knowledge that shapes the city:the human city beneath the social city

In the Atlanta Symposium (Hillier, 2001, 2003a) a theory of the social constructionof the city was presented. In this paper it is proposed that underlying the variouskinds of social city there is a deeper, more generic human city, which arises from thepervasive intervention of the human cognitive subject in the shaping and workingof the city. This intervention is explored at two critical stages in the forming of thecity: in the 'vertical' form-creating process by which the accumulation of built formscreates an emergent spatial pattern; and in the 'lateral' form-function process bywhich the emergent spatial pattern shapes movement and sets off the process bywhich an aggregate of buildings becomes a living city. The nature of these cognitiveinterventions is investigated by asking a question: how do human beings 'synchronise'diachronically acquired (and diachronically created) spatial information into asynchronic picture of ambient urban spatial patterns, since it is such synchronicpictures which seem to mediate both interventions? A possible answer is sought bydeveloping the concept of 'description retrieval', originally proposed in 'The SocialLogic of Space' as the means by which human beings retrieve abstract informationfrom patterns of relations in the real world. Our ability to retrieve such descriptionhappens, it is argued, at more than one level, and can includes the high-level notionsof the grid which seems to plays a key role in cognitive intervention in the city.Finally we ask what the ubiquity of the human cognitive subject in the formation ofthe city implies for how we should see cities as complex systems. It is argued that,as with language, there is a 'objective subject' at the heart of the processes by whichcities come into existence, and that this provides us both with the need and themeans to mediate between the social physics paradigm of the city, with its focus onthe mathematics of the generation of the physical city and phenomenologicalparadigm with its - too often anti-mathematical - focus on the human experience ofthe city. Since the intervention of the cognitive subject involves formal ideas andhas formal consequences for the structure of the city, we cannot, it is argued, explaineither without the other

A theory of the city as object: or, how spatial laws mediate the social construction of urban space

A series of recent papers (Hillier et al 1993, Hillier 1996b, Hillier 2000) have outlined a generic process by which spatial configurations, through their effect on movement, first shape, and then are shaped by, land use patterns and densities. The aim of this paper is to make the spatial dimension of this process more precise. The paper begins by examining a large number of axial maps, and finds that although there are strong cultural variations in different regions of the world, there are also powerful invariants. The problem is to understand how both cultural variations and invariants can arise from the spatial processes that generate cities. The answer proposed is that socio-cultural factors generate the differences by imposing a certain local geometry on the local construction of settlement space, while micro-economic factors, coming more and more into play as the settlement expands, generate the invariants

The fuzzy boundary: the spatial definition of urban areas

Cities seem to have some kind of area structure, usually distinguished in terms of land use types, socio-economic variables, physical appearance or historical and culturalcharacteristics. Is there any possibility that urban areas could in general be differentiated from the spatial perspective? What is the nature of boundaries between areas in terms of space? These questions could be approached by the analysis of internal or contextual spatial structure, or the relation between the two. Most studies on area structure however had focused in the main on the internal area with a secondaryrole for the context. Is there any way in which we could give more explicit attention to the context, following the clue that had come out of the earlier studies?This paper is to try to develop spatial techniques for identifying area boundaries, and looking at their performance in both the traditional areas, such as the Central London and the Inner City of Beijing, and the new development of the London Docklands. It focuses on explicitly exploring the properties of contextual structure in the formation ofarea boundaries rather than simply the properties of internal structure. After much experimentation, a new technique was arrived at for exploring properties of the context. Each axial line or segment in the whole map is taken as the root of a graph, and the numbers of axial lines, or segments, found with increasing radius from the root is calculated, and expressed as a rate of change. This rate of change value is thenassigned to the original axial line and expressed through bands of color. The results show strong areal effects, in that groups of neighbouring lines tend to have similar coloring, and in many cases, these suggest natural areas.Through the case studies, this paper suggests that historic areas typically have what we will call fuzzy boundaries. Fuzzy boundaries arise from the way space is structured internally and how this relates to the external structure of space. Such boundaries can be effective in supporting functional differentiation of areas or the growth of areal identities and characters, but do not depend on the area being either spatially self contained or geometrically differentiated, or having clear spatial limits. It is the relation of urban areas and their further surroundings that determine fuzzy boundaries of these urban areas

The Environmental Contribution to Wayfinding in Museums: Enhancement and Usage by Controlling Flows and Paths

The field of research in which wayfinding is situated refers to the way people move in reaction to environmental stimulation. It therefore fully concerns not just signage but also space designing, its geometric configuration, technical solutions and their material characterization. The focus is consequently on environmental factors that facilitate wayfinding in a museum (accessibility, visibility, etc.) and on other elements such as spatial configuration, architectural features and functional aspects. These factors influence relational phenomena and therefore visitors’ satisfaction. Methods and tools for designing and managing spaces have been studied in the research. The configurational analysis method of space has been used to objectify syntactic features of space. In particular, the outcomes of an experimental project, which have been analyzed in a master’s thesis on the re-functionalization of the museum of Palazzo dei Diamanti in Ferrara, are presented. Permeability, proximity, connections of spaces, namely meaningful features to ensure wayfinding have been examined. Space parameters resulting from the geometry of the layout, from the visual connections and from the changes of direction were then evaluated. The outcomes have been used as inputs for designing a unitary tour route circuit, that also reconnects the museum’s second floor, and for planning three independent alternative routes for a differentiated use of the museum

Joint Tests for Zero Restrictions on Non-negative Regression Coefficients

Three tests for zero restrictions on regression coefficients that are known to be nonnegative are considered: the classical F test, the likelihood ratio test, and a one-sided t test in a particular direction. Critical values for the likelihood ratio test are given for the cases of two and three restrictions, and the power function is calculated for the case of two restrictions. The analysis is conducted in terms of a characterization of the clas all similar tests for the problem, of which each of the above tests is a member. The likelihood ratio test emerges as the preferred test.Likelihood ratio test; One-sided alternative; Regression; Similar regions.