Geometric and material constraints in parametric modelling : the design to fabrication process

Parametric modelling, commonly used in the automotive and aerospace industries, has recently been adopted in the architecture and construction fields. The ability to design small repeatable components and apply them to a larger governing surface geometry is one area of parametric modelling that has great design potential. This two level modelling control, of component and overall surface, can allow designers to explore new types of form generation subject to parametric constraints. This paper reports on the design to fabrication process using repeatable components over a governing or carrier surface. The paper reports on our study of the requirements and possible solutions for successfully controlling a repeatable element, known as a Representative Volumetric Element (RVE), using geometric parameters of a larger governing surface geometry and material properties. This modelling process, coupled with Rapid
Manufacturing (RM) and Computer Numerically Controlled (CNC) machines has the potential to significantly reduce the interface between design and fabrication.

A surface characterisation and microstructural study by scanning electron microscopy of the N-methyl-n-alkylpyrrolidinium tetrafluoroborate organic salts

A microstructural characterisation of the family of N-methyl-N-alkylpyrrolidinium tetrafluoroborate organic salts was carried out by observation of powder surface morphologies with the aim of extending the microstructure-property correlation. Inherent difficulties limiting extensive studies of organic solids by SEM, including volatility under vacuum, charging due to electron beam irradiation, and air-sensitivity were overcome with the use of a Field Emission SEM and cryostage attachment. This technique, providing considerable improvements in image quality at low accelerating voltages, enabled direct observation of complex microstructural features in samples exhibiting high temperature plastic crystalline phases (N,N-dimethylpyrrolidinium tetrafluoroborate [P11BF4]; N-methyl-N-ethylpyrrolidinium tetrafluoroborate [P12BF4]; N-methyl-N-propylpyrrolidinium tetrafluoroborate [P13BF4]). Extensive lattice imperfections including grain boundaries, slip planes and dislocation pits were observed within particles of approximately 200 mgrm diameter. The N-methyl-N-butylpyrrolidinium tetrafluoroborate (P14BF4) sample in this series revealed columnar single crystals with high aspect ratios. The origin of plastic flow properties is discussed using single crystal and polycrystalline slip observations and a relationship proposed between defect characteristics and transport properties.

A novel monotonic fixed-point algorithm for l1-regularized least square vector and matrix problem

Least square problem with l₁ regularization has been proposed as a promising method for sparse signal reconstruction (e.g., basis pursuit de-noising and compressed sensing) and feature selection (e.g., the Lasso algorithm) in signal processing, statistics, and related fields. These problems can be cast as l₁-regularized least-square program (LSP). In this paper, we propose a novel monotonic fixed point method to solve large-scale l₁-regularized LSP. And we also prove the stability and convergence of the proposed method. Furthermore we generalize this method to least square matrix problem and apply it in nonnegative matrix factorization (NMF). The method is illustrated on sparse signal reconstruction, partner recognition and blind source separation problems, and the method tends to convergent faster and sparser than other l₁-regularized algorithms.

Glaucoma and on-road driving performance

PURPOSE. To investigate the on-road driving performance of patients with glaucoma.

METHODS. The sample comprised 20 patients with glaucoma and 20 subjects with normal vision, all licensed drivers, matched for age and sex. Driving performance was tested over a 10-km route incorporating 55 standardized maneuvers and skills through residential and business districts of Halifax, Nova Scotia, Canada. Testing was conducted by a professional driving instructor and assessed by an occupational therapist certified in driver rehabilitation, masked to participant group membership and level of vision. Main outcome measures were total number of satisfactory maneuvers and skills, overall rating, and incidence of at-fault critical interventions (application of the dual brake and/or steering override by the driving instructor to prevent a potentially unsafe maneuver). Measures of visual function included visual acuity, contrast sensitivity, and visual fields (Humphrey Field Analyzer; Carl Zeiss Meditec, Inc., Dublin, CA; mean deviation [MD] and binocular Esterman points).

RESULTS. There was no significant difference between patients with glaucoma (mean MD = −1.7 dB [SD 2.2] and −6.5 dB [SD 4.9], better and worse eyes, respectively) and control subjects in total satisfactory maneuvers and skills (P = 0.65), or overall rating (P = 0.60). However, 12 (60%) patients with glaucoma had one or more at-fault critical interventions, compared with 4 (20%) control subjects (odds ratio = 6.00, 95% CI, 1.46–24.69; higher still after adjustment for age, sex, medications and driving exposure), the predominant reason being failure to see and yield to a pedestrian. In the glaucoma group, worse-eye MD was associated with the overall rating of driving (r = 0.66, P = 0.002).

CONCLUSIONS. This sample of patients with glaucoma with slight to moderate visual field impairment performed many real-world driving maneuvers safely. However, they were six times as likely as subjects with normal vision to have a driving instructor intervene for reasons suggesting difficulty with detection of peripheral obstacles and hazards and reaction to unexpected events.

Relationship between vision impairment and ability to perform activities of daily living

Purpose: To determine the relationship between clinical measures of vision impairment and the ability to perform activities of daily living (ADLs).

Methods: One hundred and twenty subjects with low vision from a variety of causes participated in the study. Vision impairment was assessed under binocular conditions by measuring distance visual acuity, near word acuity, Melbourne Edge Test contrast sensitivity, Pelli–Robson Chart contrast sensitivity and visual fields. The ADL performance was assessed using the Melbourne Low Vision ADL Index (MLVAI), which is in part an observed performance assessment of instrumental ADLs and in part a self-report assessment of basic self-care ADLs.

Results: All vision measures had a high, statistically significant correlation with MLVAI total score. Near word acuity, had the strongest correlation (rs=−0.86, p < 0.001), followed by Melbourne Edge Test contrast sensitivity (rs=0.80, p < 0.001). Visual field had the weakest correlation (rs=0.56, p < 0.001). Together, age, near word acuity, Melbourne Edge Test contrast sensitivity and visual field accounted for 82.2% (adjusted R2, p < 0.001) of the variance in MLVAI total score. All correlations obtained were higher for the observed performance assessment of instrumental ADLs than for the self-report assessment of basic self-care ADLs.

Conclusions: Clinical vision impairment measures are highly correlated with capacity to perform ADLs, as measured by the MLVAI.

Function-based single and dual point haptic interaction in Cyberworlds

Polygon and point based models dominate virtual reality. These models also affect haptic rendering algorithms, which are often based on collision with polygons. With application to dual point haptic devices for operations like grasping, complex polygon and point based models will make the collision detection procedure slow. This results in the system not able to achieve interactivity for force rendering. To solve this issue, we use mathematical functions to define and implement geometry (curves, surfaces and solid objects), visual appearance (3D colours and geometric textures) and various tangible physical properties (elasticity, friction, viscosity, and force fields). The function definitions are given as analytical formulas (explicit, implicit and parametric), function scripts and procedures. We proposed an algorithm for haptic rendering of virtual scenes including mutually penetrating objects with different sizes and arbitrary location of the observer without a prior knowledge of the scene to be rendered. The algorithm is based on casting multiple haptic rendering rays from the Haptic Interaction Point (HIP), and it builds a stack to keep track on all colliding objects with the HIP. The algorithm uses collision detection based on implicit function representation of the object surfaces. The proposed approach allows us to be flexible when choosing the actual rendering platform, while it can also be easily adopted for dual point haptic collision detection as well as force and torque rendering. The function-defined objects and parts constituting them can be used together with other common definitions of virtual objects such as polygon meshes, point sets, voxel volumes, etc. We implemented an extension of X3D and VRML as well as several standalone application examples to validate the proposed methodology. Experiments show that our concern about fast, accurate rendering as well as compact representation could be fulfilled in various application scenarios and on both single and dual point haptic devices.

Cross-validation of the factorial structure of the Neighborhood Environment Walkability Scale (NEWS) and its abbreviated form (NEWS-A)

Background : The Neighborhood Environment Walkability Scale (NEWS) and its abbreviated form (NEWS-A) assess perceived environmental attributes believed to influence physical activity. A multilevel confirmatory factor analysis (MCFA) conducted on a sample from Seattle, WA showed that, at the respondent level, the factor-analyzable items of the NEWS and NEWS-A measured 11 and 10 constructs of perceived neighborhood environment, respectively. At the census blockgroup (used by the US Census Bureau as a subunit of census tracts) level, the MCFA yielded five factors for both NEWS and NEWS-A. The aim of this study was to cross-validate the individual- and blockgroup-level measurement models of the NEWS and NEWS-A in a geographical location and population different from those used in the original validation study.

Methods : A sample of 912 adults was recruited from 16 selected neighborhoods (116 census blockgroups) in the Baltimore, MD region. Neighborhoods were stratified according to their socio-economic status and transport-related walkability level measured using Geographic Information Systems. Participants self-completed the NEWS. MCFA was used to cross-validate the individual- and blockgroup-level measurement models of the NEWS and NEWS-A.

Results : The data provided sufficient support for the factorial validity of the original individual-level measurement models, which consisted of 11 (NEWS) and 10 (NEWS-A) correlated factors. The original blockgroup-level measurement model of the NEWS and NEWS-A showed poor fit to the data and required substantial modifications. These included the combining of aspects of building aesthetics with safety from crime into one factor; the separation of natural aesthetics and building aesthetics into two factors; and for the NEWS-A, the separation of presence of sidewalks/walking routes from other infrastructure for walking.

Conclusion : This study provided support for the generalizability of the individual-level measurement models of the NEWS and NEWS-A to different urban geographical locations in the USA. It is recommended that the NEWS and NEWS-A be scored according to their individual-level measurement models, which are relatively stable and correspond to constructs commonly used in the urban planning and transportation fields. However, prior to using these instruments in international and multi-cultural studies, further validation work across diverse non-English speaking countries and populations is needed.

Extensions to knowledge acquisition and effect of multimodal representation in unsupervised learning

The phenomenal behaviour and composition of human cognition is yet to be defined comprehensibly. Developing the same, artificially, is a foremost research area in artificial intelligence and related fields. In this chapter we look at advances made in the unsupervised learning paradigm (self organising methods) and its potential in realising artificial cognitive machines. The first section delineates intricacies of the process of learning in humans with an articulate discussion of the function of thought and the function of memory. The self organising method and the biological rationalisations that led to its development are explored in the second section. The next focus is the effect of structure restrictions on unsupervised learning and the enhancements resulting from a structure adapting learning algorithm. Generation of a hierarchy of knowledge using this algorithm will also be discussed. Section four looks at new means of knowledge acquisition through this adaptive unsupervised learning algorithm while the fifth examines the contribution of multimodal representation of inputs to unsupervised learning. The chapter concludes with a summary of the extensions outlined.

Mediatization and education: a sociological account

This chapter presents an account of the mediatization of education policy through a focus on the development and uptake of the knowledge economy discourse in national education policy and research settings. During the late 20th and early part of the 21st century, Australia, like other nation states around the globe, came to adopt the knowledge economy discourse as a kind of meta-policy that would help connect a variety of statistical indicators and provide direction for a number of policy areas, including education, science, and research funding. In Australia the adoption of a knowledge economy discourse was preceded by coverage from specialized sections of the quality print media, discussed broadly as a debate about the social contract that was afforded to fields charged with developing and producing national capacities for knowledge production. Such a debate mirrored similar claims by Michael Gibbons in the late 1990s, where he argued for a new social contract between science and society. Given the media coverage surrounding the uptake of the knowledge economy discourse and the promotion of the concept by the OECD, this chapter presents an account of the emergence of the knowledge economy discourse through a focus on the mediatization of the concept. The broad argument presented in this account is that what could be called “mediatization effects”, related to the promotion and adoption of policy concepts, are variable, and reach the broader public in inconsistent, time-bound, and sporadic patterns. In order to understand mediatization effects in respect of policy, the paper draws on a broad Bourdieuian informed conceptual framework to understand different kinds of fields, their logics of practice, and importantly here, cross-field effects. Specifically, the focus is on those cross-field effects related to the impact of practices within both national and global fields of journalism on national and global fields of education policy. While the case is an Australian one, the account explores general and more broadly applicable ways to understand links between the globalization and the mediatization of policy.

The third space : Metaphor and the disturbing observer

This book is a collaboration with a poet,a painter and two literary critics/philosophers. It is an investigation into aesthetics and examines and presents the possibilities for a poet and a painter in going beyond appropriating words and images from practitioners within their respective verbal and visual fields. In this book, the poet and the painter have been placed in a dialogic position to each other. This book attempts to create further meaning in the positioning of poems alongside paintings. It is a book about the processes of creativity, the making of art, the irresolvable dilemma of attempting to create from a world from which one cannot separate. The subject matter deals with art processes when attempting to re-discover lost identities with a focus on historical, psychological and political contexts

Unhealthy food, integrated marketing communication and power: a critical analysis

Public health advocates have repeatedly highlighted parallels between food marketing and childhood obesity. Yet existing literature has not explored the connection between the promotion of unhealthy foods and beverages, certain characteristics of integrated marketing communication (IMC) and the power of multinational food and beverage companies. This is problematic because IMC represents the dominant marketing paradigm in use today. This article draws on critical theory and literature from across public health, marketing, business and related fields. By focusing on macro-level antecedents and interactions, this discussion highlights a previously unarticulated dimension of the promotion of unhealthy foods and beverages to children and adolescents. In doing so, this discussion aims to generate greater recognition of the broader environmental circumstances and processes that surround food marketing tactics and their consequences for public health nutrition. This perspective will also contribute to an expanded understanding of unhealthy food marketing and its unintended consequences, among an audience of nutrition, public health and policy communities.

Aboriginal and Torres Strait Islander People in the accounting profession : an exploratory study

The aim of this article is to explore the role that accounting skills and accounting qualifications may play in entering fields that have been virtually closed to Aboriginal and Torres Strait Islander (ATSI) people. It is acknowledged in the literature that accounting processes and accountants have historically had a domineering and detrimental impact on marginalised groups, such as ATSI peoples. However, we propose an alternative viewpoint using a Bourdieun perspective and theorise that accounting skills and accounting qualifications (capital) can open doors to powerful organisations and institutions (fields). As this is an exploratory study, we have limited our analysis to one key aspect of the Bourdieun framework, namely that of field. To that end, we examine accounting and other organisations that have traditionally closed their doors to marginalised groups in society. Interviews were conducted with ATSI people who have successfully gained entry into the field of the accounting profession, in an effort to understand the experiences and barriers they faced and to investigate the role that accounting skills plays in enabling ATSI people access to fields and decision-making positions that have traditionally been inaccessible to them.

New approaches for studies of Muslim women and sport

This article offers a new approach for examining Muslim women in sport, which combines the domains of sporting participation, consumption and representation. It proposes moving beyond a sports development paradigm and deficit model of sports participation, whereby marginal communities are incorporated into the mainstream by playing sport, to take account of other ways that people engage with sport as consumers and fans. Conceptually, this approach is informed by transnational feminist perspectives, which foreground the role of power hierarchies in the production of knowledge about the sporting female Other. It suggests that sport practitioners, scholars and policy makers pay greater theoretical attention to how Muslim women are constructed within sport discourses. By widening the research focus to consider consumption and representation, possibilities emerge to expand on the narrow research and policy fields of ‘ethnicity’ and ‘well-being’ focused on physical health outcomes through which Muslim women’s engagement with sport is commonly framed.

Antitumor and antimycobacterial activities of cyclopalladated complexes: X-ray structure of [Pd(C-2,N-dmba)(Br)(tu)] (dmba = N,N-dimethylbenzylamine, tu = thiourea)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Structure and antimycobacterial activity of the novel organometallic [Pd(C-bzan)(SCN)(dppp)] compound

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)