633 research outputs found

    Managing Accessibility — The Configurational Approach to the Inclusive Design of Urban Spaces

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    This paper concerns the theme of the universal accessibility to urban spaces, proposing the contribution of configurational approach to their inclusive design. Several questions persuade that a merely functional approach, essentially based on the position of the located activities, cannot be said satisfying: only a configurational approach can account for the effects of the grid configuration on the actual accessibility of its spaces. This research focuses on Italian urban settlements, which appear as ideal case studies, due to the typical consistency of their urban spaces, which, especially in the inner historical cores, are densely build, geometrically irregular and hence generally far from actually providing a universal material accessibility. Here the impedance of space is much more than a theoretical hypothesis and concrete interventions are generally requested to eliminate or reduce its barriers and to make space actually and safely usable. Rather than at indicating the technical solution of single urban problems, which of course are strongly different each other, the research aims at defining a method suitable for any local context. Such method, integrating into a reliable tool the configurational vision with the functional and interactional approach, will provide a hierarchy of urban spaces with reference to the necessity of their universal accessibility

    Homothetic Behavior of Betweenness Centralities: A Multiscale Alternative Approach to Relate Cities and Large Regional Structures

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    Regional configuration can reveal important aspects about city sustainability, as local-regional interactions shape the evolution and inner geography of urban settlements. However, modelling these large-scale structures remains a challenge, due to their sheer size as physical objects. Despite recent improvements in processing power and computing methods, extensive time periods are still required for ordinary microprocessors to model network centralities in road-graphs with high element counts, connectivity and topological depth. Generalization is often the chosen option to mitigate time-constraints of regional network complexity. Nevertheless, this can impact visual representation and model precision, especially when multiscale comparisons are desired. Tests using Normalized Angular Choice (NACH), a Space Syntax mathematical derivative of Betweenness Centrality, found recursive visual similitudes in centrality spatial distribution when modelling distinct scaled map sections of the same large regional network structure. Therefore, a sort of homothetic behavior is identified, since statistical analyses demonstrate that centrality values and distributions remain rather consistent throughout scales, even when considering edge effects. This paper summarizes these results and considers homotheties as an alternative to extensive network generalization. Hence, data maps can be constructed sooner and more accurately as “pieces of a puzzle”, since each individual lesser scale graph possesses a faster processing time

    A square for people a visually communicative, configuration informed and social-oriented redevelopment project for Largo da Graça, Lisbon

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    This paper describes an experimental project in which the urban designer uses Space Syntax and other analysis techniques coming from Public Life Studies and Building Thermal Physics, to inform the Design Decision-Making for the redevelopment of a public square. Largo da Graça in the historic centre of Lisbon was selected as a case study, suitable for testing many possible and different design changes when space syntax is embedded in the design decisions. The experiment generated a digital workflow with all the steps undertaken in solving design problems, a ‘design journal’ that includes efficiency targets (centrality, connectivity, enclosure, thermal comfort, social security, equality, and interaction) and a comparative test of the design proposals. The adopted design strategy, as well as the examples extracted from the workflow, could be used to illustrate a link between research and design, adequate for supporting and orientating the project and design of urban spaces

    Swift and Fermi observations of X-ray flares: the case of Late Internal Shock

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    Simultaneous Swift and Fermi observations of gamma-ray bursts (GRBs) offer a unique broadband view of their afterglow emission, spanning more than ten decades in energy. We present the sample of X-ray flares observed by both Swift and Fermi during the first three years of Fermi operations. While bright in the X-ray band, X-ray flares are often undetected at lower (optical), and higher (MeV to GeV) energies. We show that this disfavors synchrotron self-Compton processes as origin of the observed X-ray emission. We compare the broadband properties of X-ray flares with the standard late internal shock model, and find that, in this scenario, X-ray flares can be produced by a late-time relativistic (Gamma>50) outflow at radii R~10^13-10^14 cm. This conclusion holds only if the variability timescale is significantly shorter than the observed flare duration, and implies that X-ray flares can directly probe the activity of the GRB central engine.Comment: 13 pages, 4 figures, accepted for publication in Ap

    Urban squares morphologies, contributes of a multidimensional analysis

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    The word Square and the Latin – platea – derived terms (piazza, plaza, praça, piaţă) are used to identify a public space of an exceptional character that is morphologically distinct in the urban morphology. The study of urban morphology seeks to understand the spatial structure and character of the city by identifying the patterns of its elements and the process of its development. The characterizing traits of the urban square are diverse and their origin twofold: global properties, referred to its relationships within the whole grid, and local properties, depending on the intrinsic morphologic features of its space; what requires a multi-dimensional and multi-scale approach. This paper will present a multidimensional analysis of two Italian Tuscan historic squares and two Portuguese historic squares. The squares will be analysed from a simultaneous view of their attributes. Thus, it is proposed, in an ongoing joint research project, to address the limitations of traditional-descriptive urban morphology in dealing with this simultaneity. Developing the relations between formal attributes and intangible spatial properties, their identity and closeness may be disclosed by multivariate statistical analysis and computational techniques.info:eu-repo/semantics/acceptedVersio

    Project methodology for the reversion of industrial sites located in periurban context, a case study in the 'Città Futura' of Piombino (LI)

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    The aim of the project was to identify a design methodology for the conversion of disused industrial sites, proposing the application of this method to a real case study, the area called "Future City" located in the Municipality of Piombino (LI). Starting from an analysis of the previous urban planning forecasts, the work began initially to identify the weaknesses of these forecasts. Given the state of soil pollution, the main obstacle to the realization of an urban reconversion was the one linked to the high reclamation costs usually connected to industrial sites. The focus was therefore to identify alternative solutions to overcome this obstacle. Going beyond what are usually the solutions envisaged for these problems, we proceeded to identify an intervention based on two key ideas: minimizing the volume of waste to be removed and giving it to landfill and using techniques of phytoremediation for the reclamation (Kennen & Kirkwoon, 2015; Pulford & Watson, 2003; Schwitzguébel, 2017). After a careful evaluation of the main characteristics linked to an intervention of this type it was concluded that it represents a very valid method for the reduction of reclamation costs (Rubeo, 2012). The work included a careful study of plant species spontaneously grown on the spot despite the unfavourable characteristics of the land (pH=12-13), in order to identify the most suitable species to be reused within a renaturalization intervention. A preliminary project was therefore proposed relating to the urban development of the area, in such a way as to highlight the potential of the same in terms of benefits to the community, as well as in aesthetic and environmental terms: the reconversion of the area (clearly state of abandonment) in a place dedicated mainly to green spaces therefore represented the best solution, also in light of an economic-financial analysis (Del Giudice, 2010). Finally, the methodology identified lends itself well to being applied to all areas subtracted from industrial use for which reconversion is necessary for public use, without prejudice to the objective of reducing the overall costs of intervention and maximizing benefits

    Assessing the impact of temporary housing sites on urban socio-spatial performance: the case of the Central Italy earthquake

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    This paperadvocatesa performance-based approach to the planningof temporary housing sites after sudden urban disasters. A “functionally graded”configurational analysis method is usedto assess,quantitatively and qualita-tively,thesocio-spatial impact of government-led housing assistance provisionacrossthe regional,urbanandneighbourhoodscales. To highlight the differentoutcomes achieved in different urban contextsby apparently similar housing re-covery plans, adiachronic comparative studyof four epicentral historic townshit by the 2016-2017Central Italyearthquakesis performed.The researchanalysestheconfigurationalpropertiesof these settlements at four critical points in time: before the disaster; right after it(emergency phase); during disaster recovery; after the reconstruction is completed. This paper builds on previous research on rapid urban modelling and economic spatial analysis workflows to respond to potential implementationchallenges,which include time constraints and geo-data availabilityissues after disasters. By using a real case scenario,this study seeks to demonstratethe potential benefitsof adopting the proposed multidimensional spatialanalysis methodto foster the delivery of integrated housing recovery so-lutions, which contribute to sustainable urban developmentTheseencompassin-forming, timely updating,and coordinatingstrategic, management,and opera-tional decisions related to the design and planningof temporary housing sites

    A study of the prompt and afterglow emission of the Short GRB 061201

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    Our knowledge of the intrinsic properties of short duration Gamma-Ray Bursts has relied, so far, only upon a few cases for which the estimate of the distance and an extended, multiwavelength monitoring of the afterglow have been obtained. We carried out multiwavelength observations of the short GRB 061201 aimed at estimating its distance and studying its properties. We performed a spectral and timing analysis of the prompt and afterglow emission and discuss the results in the context of the standard fireball model. A clear temporal break was observed in the X-ray light curve about 40 minutes after the burst trigger. We find that the spectral and timing behaviour of the X-ray afterglow is consistent with a jet origin of the observed break, although the optical data can not definitively confirm this and other scenarios are possible. No underlying host galaxy down to R~26 mag was found after fading of the optical afterglow. Thus, no secure redshift could be measured for this burst. The nearest galaxy is at z=0.111 and shows evidence of star formation activity. We discuss the association of GRB 061201 with this galaxy and with the ACO S 995 galaxy cluster, from which the source is at an angular distance of 17'' and 8.5', respectively. We also test the association with a possible undetected, positionally consistent galaxy at z~1. In all these cases, in the jet interpretation, we find a jet opening angle of 1-2 degrees.Comment: 10 pages, 7 figures, accepted for publication in A&
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