Cities as emergent models: the morphological logic of Manhattan and Barcelona

This paper is set to unveil several particulars about the logic embedded in the diachronic model of city growth and the rules which govern the emergence of urban spaces. The paper outlines an attempt to detect and define the generative rules of a growing urban structure by means of evaluation techniques. The initial approach in this regards will be to study the evolution of existing urban regions or cities which in our case are Manhattan and Barcelona and investigate the rules and causes of their emergence and growth. The paper will concentrate on the spatial aspect of the generative rules and investigate their behaviour and dimensionality. Several Space Syntax evaluation methods will be implemented to capture the change of spatial configurations within the growing urban structures. In addition, certain spatial elements will be isolated and tested aiming to illustrate their influence on the main spatial structures. Both urban regions were found to be emergent products of a bottom up organic growth mostly distinguished in the vicinities of the first settlements. Despite the imposition of a uniform grid on both cities in later stages of their development these cities managed to deform the regularity in the preplanned grid in an emergent manner to end up with an efficient model embodied in their current spatial arrangement. The paper reveals several consistencies in the spatial morphology of both urban regions and provides explanation of these regularities in an approach to extract the underlying rules which contributed to the growth optimization process

The isomorphism conjecture for 3-manifold groups and K-theory of virtually poly-surface groups

This article has two purposes. In \cite{R3} (math.KT/0405211) we showed that the FIC (Fibered Isomorphism Conjecture for pseudoisotopy functor) for a particular class of 3-manifolds (we denoted this class by \cal C) is the key to prove the FIC for 3-manifold groups in general. And we proved the FIC for the fundamental groups of members of a subclass of \cal C. This result was obtained by showing that the double of any member of this subclass is either Seifert fibered or supports a nonpositively curved metric. In this article we prove that for any M in {\cal C} there is a closed 3-manifold P such that either P is Seifert fibered or is a nonpositively curved 3-manifold and \pi_1(M) is a subgroup of \pi_1(P). As a consequence this proves that the FIC is true for any B-group (see definition 3.2 in \cite{R3}). Therefore, the FIC is true for any Haken 3-manifold group and hence for any 3-manifold group (using the reduction theorem of \cite{R3}) provided we assume the Geometrization conjecture. The above result also proves the FIC for a class of 4-manifold groups (see \cite{R2}(math.GT/0209119)). The second aspect of this article is to relax a condition in the definition of strongly poly-surface group (\cite{R1} (math.GT/0209118)) and define a new class of groups (we call them {\it weak strongly poly-surface} groups). Then using the above result we prove the FIC for any virtually weak strongly poly-surface group. We also give a corrected proof of the main lemma of \cite{R1}.Comment: 12 pages, AMS Latex file, 1 figure, final version. accepted for publication in K-theor

Towards an extended network-based description for BIM and Smart Cities

The pervasive deployment of “smart city” and “smart building” projects in cities world-wide is driving innovation on many fronts including; technology, telematics, engineering and entrepreneurship. Traditionally, descriptive models of built form were adapted to predict performance by using few data sets. This trend has recently diverted towards making short-term predictions and visualizing real-time information enabled by Big Data and the Internet of Things. Building and urban morphology need yet to adapt new frameworks to embrace these new technologies in the design and evolution of sustainable infrastructure. Through representing relationships between different infrastructure components and linking the resultant network to smart systems, it is perhaps possible to provide better predictions of the operational performance of buildings and cities. This workshop was dedicated to provide a platform for discussing these challenges between academics, construction and engineering experts, and policy makers. Together with a team of academics and researchers from UCL, the BIM Task Group at the Government Department of Business Innovation and Skills has scored success at releasing the Digital Built Britain construction strategy. The strategy will execute the UK government plans for BIM Level’3, making a shift from file-based collaboration to the more scalable and flexible semantic web. This is thought to provide opportunities for acquiring information about how performance data could support the design and operation phases of buildings and how BIM could constitute a bottom up approach to smart cities. The “Towards an extended network-based description for BIM and Smart Cities” workshop, which took place at Space Syntax Limited, was dedicated to tackle these challenges and plan for a start on the BIM level’3 project by attending to the morphological and performance aspects of the built environment and the wealth of research that was done in this field at UCL over the last decades. The workshop was intended to discuss a wide-range of theoretical frameworks and representational schemes for establishing network-based models as to structure data in building and urban information models and respond to social and environmental performance requirements of the built environment. The workshop has also discussed some applications and challenges presented by IoT, and by the data available on energy performance of buildings. The core discussion was centred on whether network-based models are fundamental to comprehend and represent the complexity of cities and inform urban design and public policy practices, during the design, construction, and operation phases of infrastructure projects

Discursive and Non-Discursive Design Processes

This research study investigates the hypothesis that Space Syntax plays a role in enhancing architectural design as a knowledge-based process by bringing the nondiscursive design process onto a discursive level, and by making explicit the logic of processing, evaluating, and reasoning about design. In order to establish an evidencebased argument for this hypothesis the study will scrutinize the performances and outcomes of architects solving a well-defined problem. The paper constructs the study on a literature background exploring the different theories which were concerned with the analysis and evaluation of design processes and outcomes. The analysis of design processes was investigated on micro and macro scales and the evaluation of solutions was considered in terms of spatial configurations and the social organization embodied in space. The research then goes on to apply some of these analytical studies to a set of design tasks made by architects who have a background in Space Syntax theory, and architects with other architectural backgrounds. The question then turns to the influence of Space Syntax theory on the strategies and cognitive actions of the design processes and the observational study will attempt to prove whether the knowledge of Space Syntax can have a positive effect on architects during their design process, taking into consideration that Space Syntax, as a morphic language, can render the non-discursive discursive of architecture. In the following step the design solutions are evaluated in terms of qualities regarding social organization, and in terms of quantities measuring the values of their spatial configurations. The analysis of the design processes and outcomes will show differences between the two groups of architects, in addition to some individual differences between the architects. Thus this research proves that the knowledge of space syntax may partially enhance the productivity of design process by making it more explicit

Teaching principles of network and agent-based models to architecture students

Architectural design is necessarily a situated learning process that continues to be a subject of interest in architectural education. Whether designers should give preference to a functional design product or whether the focus should be centered on creative output are issues that need to be questioned. Given the typically vague descriptions of creativity it is even harder to determine whether design functionality and design creativity should be treated as separate entities. The implications of any preferences made on the methods of assessment are crucial. While teaching is necessarily aligned to design as an experiential learning process, it also requires careful understanding of how knowledge can inform rather than constrain creativity. In evaluating the creativity or even the functionality of a design there are challenges present in accounting for a comprehensive and yet practical framework for assessment. In teaching practices the challenge is to ensure that the assessment process is sufficiently specified without limiting creative explorations. It is argued that through exposing design propositions to internal and external criticism, assessing progress becomes less of a challenge. In this course of development 'creativity' is revealed not as value-neutral but as a product of a social process that is practiced through experiential learning

Virtual Communities and Patterns of Social Interactions in ‘Tech City’

The impact of social media and Web 2.0 on socioeconomic behaviour in the physical space of the built environment had recently become a matter of intense debate in social sciences and human geography. This paper examines the relationship between the configurations of urban space from the perspective of 'space syntax' theory by Hillier and Hanson (1984) and the configurations of social networks in Twitter, whilst focusing on the technology start-up cluster in 'Tech City' London. Where there has been arguments made for a strong correlation between twitter ties in businesses and physical distance, this research is focused on the borough scale aiming to outline a relationship between the configurations of streets and the virtual and socioeconomic attributes of start-up businesses. The paper reports a moderate relationship between indices of centrality in twitter network and its correspondent measure in street networks. In addition, the research yields global and temporal patterns of relationships with land uses and land values. The paper concludes by reflecting on how the configurations of twitter Tech-City community are present in the physical medium, where short and long links define the local and global part-whole relationship between Tech-City and other communities

Comparison of Decision Rules for Subsurface Drip Irrigation Practices Using a Nonlinear Mathematical Programming Model

A comparison of decision rules has been made for case studies of corn production using subsurface drip irrigation under three agricultural management practices (no irrigation, uniform irrigation, and variable rate irrigation). The uniform irrigation strategy appeared to perform the best than the other two management practices under different risk scenarios.corn production, mathematical programming, profitability, risk management, subsurface drip irrigation, variable rate irrigation, Farm Management,

Entrained defects and mechanical properties of aluminium castings

The presence of entrained double oxide films, known as bifilms, has been identified as a contributing factor to the variability in mechanical properties observed in aluminium castings. These bifilms consist of folded-over oxide films containing gas-filled crevices and are formed due to turbulence on the liquid metal's surface during handling and pouring. Additionally, it has been suggested that hydrogen dissolved in the aluminium melt can permeate these defects, causing them to expand and leading to the formation of hydrogen porosity. This, in turn, exacerbates the detrimental effects on the mechanical properties of the castings. In this study, the ultimate tensile strength (UTS) and percentage elongation of sand cast bars were compared under various casting conditions. These parameters were chosen as indicators of casting reliability, which was expected to be influenced by the presence of oxide films. The results indicated that incorporating filters in the gating system and reducing the runner height led to a noticeable improvement in tensile strength and elongation. This improvement was attributed to enhanced mold filling conditions, which reduced the likelihood of oxide film entrainment. The findings of this research provide valuable insights into the factors that affect the properties of light metal alloy castings. By understanding these influences, it becomes possible to develop improved practices that result in healthier castings with enhanced mechanical properties

Influence of bifilm defects generated during mould filling on the tensile properties of Al–Si–Mg cast alloys

Entrapped double oxide film defects are known to be the most detrimental defects during the casting of aluminium alloys. In addition, hydrogen dissolved in the aluminium melt was suggested to pass into the defects to expand them and cause hydrogen porosity. In this work, the effect of two important casting parameters (the filtration and hydrogen content) on the properties of Al–7 Si–0.3 Mg alloy castings was studied using a full factorial design of experiments approach. Casting properties such as the Weibull modulus and position parameter of the elongation and the tensile strength were considered as response parameters. The results suggested that adopting 10 PPI filters in the gating system resulted in a considerable boost of the Weibull moduli of the tensile strength and elongation due to the enhanced mould filling conditions that minimised the possibility of oxide film entrainment. In addition, the results showed that reducing the hydrogen content in the castings samples from 0.257 to 0.132 cm3/100 g Al was associated with a noticeable decrease in the size of bifilm defects with a corresponding improvement in the mechanical properties. Such significant effect of the process parameters studied on the casting properties suggests that the more careful and quiescent mould filling practice and the lower the hydrogen level of the casting, the higher the quality and reliability of the castings produced