Inside High-Rise Housing

EPDF and EPUB available Open Access under CC-BY-NC-ND licence. Condominium and comparable legal architectures make vertical urban growth possible, but do we really understand the social implications of restructuring city land ownership in this way? Geographer and architect Megan Nethercote enters the condo tower to explore the hidden social and territorial dynamics of private vertical communities. Informed by residents’ accounts of Australian high-rise living, this book shows how legal and physical architectures fuse in ways that jeopardize residents’ experience of home and stigmatize renters. As cities sprawl skywards and private renting expands, this compelling geographic analysis of property identifies high-rise development’s overlooked hand in social segregation and urban fragmentation, and raises bold questions about the condominium’s prospects

An Enhanced Features Extractor for a Portfolio of Constraint Solvers

Recent research has shown that a single arbitrarily efficient solver can be significantly outperformed by a portfolio of possibly slower on-average solvers. The solver selection is usually done by means of (un)supervised learning techniques which exploit features extracted from the problem specification. In this paper we present an useful and flexible framework that is able to extract an extensive set of features from a Constraint (Satisfaction/Optimization) Problem defined in possibly different modeling languages: MiniZinc, FlatZinc or XCSP. We also report some empirical results showing that the performances that can be obtained using these features are effective and competitive with state of the art CSP portfolio techniques

Valgrind A Program Supervision Framework

AbstractValgrind is a programmable framework for creating program supervision tools such as bug detectors and profilers. It executes supervised programs using dynamic binary translation, giving it total control over their every part without requiring source code, and without the need for recompilation or relinking prior to execution.New supervision tools can be easily created by writing skins that plug into Valgrind's core. As an example, we describe one skin that performs Purify-style memory checks for C and C++ programs

High-contrast approximation for penetrable wedge diffraction

Abstract The important open canonical problem of wave diffraction by a penetrable wedge is considered in the high-contrast limit. Mathematically, this means that the contrast parameter, the ratio of a specific material property of the host and the wedge scatterer, is assumed small. The relevant material property depends on the physical context and is different for acoustic and electromagnetic waves for example. Based on this assumption, a new asymptotic iterative scheme is constructed. The solution to the penetrable wedge is written in terms of infinitely many solutions to (possibly inhomogeneous) impenetrable wedge problems. Each impenetrable problem is solved using a combination of the Sommerfeld–Malyuzhinets and Wiener–Hopf techniques. The resulting approximated solution to the penetrable wedge involves a large number of nested complex integrals and is hence difficult to evaluate numerically. In order to address this issue, a subtle method (combining asymptotics, interpolation and complex analysis) is developed and implemented, leading to a fast and efficient numerical evaluation. This asymptotic scheme is shown to have excellent convergent properties and leads to a clear improvement on extant approaches.</jats:p

Analytical methods for perfect wedge diffraction: A review

© 2019 Elsevier B.V. The subject of diffraction of waves by sharp boundaries has been studied intensively for well over a century, initiated by groundbreaking mathematicians and physicists including Sommerfeld, Macdonald and Poincaré. The significance of such canonical diffraction models, and their analytical solutions, was recognised much more broadly thanks to Keller, who introduced a geometrical theory of diffraction (GTD) in the middle of the last century, and other important mathematicians such as Fock and Babich. This has led to a very wide variety of approaches to be developed in order to tackle such two and three dimensional diffraction problems, with the purpose of obtaining elegant and compact analytic solutions capable of easy numerical evaluation. The purpose of this review article is to showcase the disparate mathematical techniques that have been proposed. For ease of exposition, mathematical brevity, and for the broadest interest to the reader, all approaches are aimed at one canonical model, namely diffraction of a monochromatic scalar plane wave by a two-dimensional wedge with perfect Dirichlet or Neumann boundaries. The first three approaches offered are those most commonly used today in diffraction theory, although not necessarily in the context of wedge diffraction. These are the Sommerfeld–Malyuzhinets method, the Wiener–Hopf technique, and the Kontorovich–Lebedev transform approach. Then follows three less well-known and somewhat novel methods, which would be of interest even to specialists in the field, namely the embedding method, a random walk approach, and the technique of functionally-invariant solutions. Having offered the exact solution of this problem in a variety of forms, a numerical comparison between the exact solution and several powerful approximations such as GTD is performed and critically assessed

Sustaining tenancies in Australia&#039;s indigenous town-camps

Indigenous housing is an enduring policy problem in Australia. Policy failure (both rhetoric and reality) has characterised the history of the design, provision and management of housing welfare for Australia’s Indigenous communities in remote and town-camp locations. While the reasons for this are complex and contested, the consequences are more clear-cut: Indigenous people face much higher levels of disadvantage than non-Indigenous Australians. The 2008 reforms mark a significant structural break in government approaches to the Indigenous housing crisis in remote and town-camps communities. Pre-2008, government endorsed a community-housing approach to Indigenous housing provision, advocating for housing policies and programs developed and administered in partnership with Indigenous communities. This policy approach was abandoned with the 2008 government endorsement of a public housing system for the provision and management of Indigenous housing in remote and town-camp communities. Informed by neoliberal views of Indigenous dysfunction, and the individual’s role in this, the government pursues a behavioural change approach to induce tenants to adopt ways of life consistent with western ways of living in a house and managing a tenancy. One important government objective in these reforms is securing sustainable tenancies for Indigenous tenants. Sustainable tenancies not only prevent tenancy failure, but help achieve positive tenancy outcomes (such as stability, security and improved health and well-being). Meeting this objective may provide an important reprieve for Indigenous people from the enduring cycle of policy failure. This thesis aims to analyse how the initial implementation of the 2008 Indigenous housing reforms can lead to sustainable tenancies for residents in town-camp communities. Qualitative research methods were employed to study changes to tenants’ ways of living in Indigenous town-camp communities in the Northern Territory and Western Australia as a result of these reforms. Interviews were conducted with Indigenous tenants and a cross-section of Indigenous housing stakeholders involved in the design and implementation of these reforms in both jurisdictions. The investigation was guided by a dual approach to the analysis of the systems of housing welfare provision and of Indigenous tenants’ lived experience of these systems in order to understand the macro- and micro-level contexts for these housing reforms, how tenants’ ways of living were evolving as a result these reforms, and where opportunities might exist to further optimise positive tenancy outcomes. The primary contribution of this thesis is to bring together a review of the current systems of housing welfare provision in town-camp communities, with a practice-based analysis of the lived experience of housing welfare in Indigenous town-camps. This thesis develop new understandings of how the sustaining tenancies agenda is met within current Indigenous housing welfare reforms, and especially how the criterion for supportive housing management might be achieved through new dynamics in public housing governance. This thesis identifies a series of issues affecting the implementation of the current Indigenous housing reforms and their capacity to attain sustainable tenancies for Indigenous tenants. It concludes by identifying a potential platform (within the constraints of these housing reforms) to optimise positive tenancy outcomes in Indigenous town-camp communities

The office of leader of the opposition in the house of representatives

The structure, role, function and significance of the Opposition in political systems constructed on the so-called Westminster model has generally been a neglected area of study, both in Britain, where the term- 'His Majesty's Opposition' -has been current since the third decade of the nineteenth century, and in Australia, where opposition has been an accepted part of parliamentary government since its inception in the sixth decade of the nineteenth century. If the Opposition has been a neglected area of study it was not for want of early and perceptive guidance from a student of politics no less eminent than the celebrated Walter Bagehot who not only noted the existence of Opposition in the living constitution but also some of the ambiguities, ironies and subtleties of the institution which later writers on politics have for so long ignored. The English Constitution, Bagehot wrote, was the first to make 'criticism of administration as much a part of the policy as administration itself'. But, at the same time, he noted that the business of Opposition is far from straight-forward, for, although its task is to oppose the Government, it nevertheless must decide on what to oppose the Government: "The Opposition have the unrestricted selection of the point of attack, and they seldom choose a case in which the department, upon the surface of the matter, seems to be right.

Theory Learning with Symmetry Breaking

This paper investigates the use of a Prolog coded SMT solver in tackling a well known constraints problem, namely packing a given set of consecutive squares into a given rectangle, and details the developments in the solver that this motivates. The packing problem has a natural model in the theory of quantifier-free integer difference logic, a theory supported by many SMT solvers. The solver used in this work exploits a data structure consisting of an incremental Floyd-Warshall matrix paired with a watch matrix that monitors the entailment status of integer difference constraints. It is shown how this structure can be used to build unsatisfiable theory cores on the fly, which in turn allows theory learning to be incorporated into the solver. Further, it is shown that a problem-specific and non-standard approach to learning can be taken where symmetry breaking is incorporated into the learning stage, magnifying the effect of learning. It is argued that the declarative framework allows the solver to be used in this white box manner and is a strength of the solver. The approach is experimentally evaluated