Student identities in a mathematical community of practice : radical visible pedagogy and the teacher collective

This study investigated the practices of two teachers in a school that was successful in enabling the mathematical learning of students in Years 1 and 2, including those from backgrounds associated with low mathematical achievement. The study explained how the practices of the teachers constituted a radical visible pedagogy that enabled equitable outcomes. The study also showed that teachers’ practices have collective power to shape students’ mathematical identities. The role of the principal in the school was pivotal because she structured curriculum delivery so that students experienced the distinct practices of both teachers.

Lattice-free descriptions of collective motion with crowding and adhesion

Cell-to-cell adhesion is an important aspect of malignant spreading that is often observed in images from the experimental cell biology literature. Since cell-to-cell adhesion plays an important role in controlling the movement of individual malignant cells, it is likely that cell-to-cell adhesion also influences the spatial spreading of populations of such cells. Therefore, it is important for us to develop biologically realistic simulation tools that can mimic the key features of such collective spreading processes to improve our understanding of how cell-to-cell adhesion influences the spreading of cell populations. Previous models of collective cell spreading with adhesion have used lattice-based random walk frameworks which may lead to unrealistic results, since the agents in the random walk simulations always move across an artificial underlying lattice structure. This is particularly problematic in high-density regions where it is clear that agents in the random walk align along the underlying lattice, whereas no such regular alignment is ever observed experimentally. To address these limitations, we present a lattice-free model of collective cell migration that explicitly incorporates crowding and adhesion. We derive a partial differential equation description of the discrete process and show that averaged simulation results compare very well with numerical solutions of the partial differential equation.

On Presence, Collective Performance and Assumptions of Causality

The ways we assume, observe and model “presence” and its effects are the focus in this paper. Entities with selectively shared presences are the basis of any collective, and of attributions (such as “humorous”, “efficient” or “intelligent”). The subtleties of any joint presence can markedly influence potentials, perceptions and performance of the collective as demonstrated when a humorous tale is counterpoised with disciplined thought. Disciplines build on presences assumed known or knowable while fluid and interpretable presences pervade humor. Explorations in this paper allow considerations of collectives, causality and the philosophy of computing. Economics has long considered issues of collective action in ways circumscribed by assumptions about the presence of economic entities. Such entities are deemed rational but they are clearly not intelligent. To reach its potential, collective intelligence research needs more adequate considerations of alternate presences and their impacts.

Odometry-driven inference to link multiple exemplars of a location

A major challenge for robot localization and mapping systems is maintaining reliable operation in a changing environment. Vision-based systems in particular are susceptible to changes in illumination and weather, and the same location at another time of day may appear radically different to a system using a feature-based visual localization system. One approach for mapping changing environments is to create and maintain maps that contain multiple representations of each physical location in a topological framework or manifold. However, this requires the system to be able to correctly link two or more appearance representations to the same spatial location, even though the representations may appear quite dissimilar. This paper proposes a method of linking visual representations from the same location without requiring a visual match, thereby allowing vision-based localization systems to create multiple appearance representations of physical locations. The most likely position on the robot path is determined using particle filter methods based on dead reckoning data and recent visual loop closures. In order to avoid erroneous loop closures, the odometry-based inferences are only accepted when the inferred path's end point is confirmed as correct by the visual matching system. Algorithm performance is demonstrated using an indoor robot dataset and a large outdoor camera dataset.

It's just an old apron : aprons, artefacts and art - representations of personal and private 'her-stories', as public histories

This paper examines art and artefact in the representation and recollection of deeply personal WWII women’s experiences as POW’s under the Japanese. This kind of treatment of internees in the Tjideng Women and Children’s internment camp (and others) in Batavia under the Japanese in WWII, stands in stark and brutal contrast to the idyllic life lived by many families up to that time in what was then known as the Dutch East Indies (Indonesia). The deprivation and brutality of the Japanese incarceration of these women and children evoked responses - not military, but certainly militant, if muted. Representations of those responses – as both art and artefact - may be found in the most unlikely places and unexpected forms - and are still being unearthed to this day. However close we might personally be to these artists and artisans, can we, as observers from a distance, ever truly comprehend through spoken or written words alone, the day-today realities of those extraordinary times?

Analysis of terrain geometry representations for traversability of a Mars rover

For a planetary rover to successfully traverse across unstructured terrain autonomously, one of the major challenges is to assess its local traversability such that it can plan a trajectory to achieve its mission goals efficiently while minimising risk to the vehicle itself. This paper aims to provide a comparative study on different approaches for representing the geometry of Martian terrain for the purpose of evaluating terrain traversability. An accurate representation of the geometric properties of the terrain is essential as it can directly affect the determination of traversability for a ground vehicle. We explore current state-of-the-art techniques for terrain estimation, in particular Gaussian Processes (GP) in various forms, and discuss the suitability of each technique in the context of an unstructured Martian terrain. Furthermore, we present the limitations of regression techniques in terms of spatial correlation and continuity assumptions, and the impact on traversability analysis of a planetary rover across unstructured terrain. The analysis was performed on datasets of the Mars Yard at the Powerhouse Museum in Sydney, obtained using the onboard RGB-D camera.

Traversability estimation for a planetary rover via experimental kernel learning in a Gaussian process framework

A critical requirement for safe autonomous navigation of a planetary rover is the ability to accurately estimate the traversability of the terrain. This work considers the problem of predicting the attitude and configuration angles of the platform from terrain representations that are often incomplete due to occlusions and sensor limitations. Using Gaussian Processes (GP) and exteroceptive data as training input, we can provide a continuous and complete representation of terrain traversability, with uncertainty in the output estimates. In this paper, we propose a novel method that focuses on exploiting the explicit correlation in vehicle attitude and configuration during operation by learning a kernel function from vehicle experience to perform GP regression. We provide an extensive experimental validation of the proposed method on a planetary rover. We show significant improvement in the accuracy of our estimation compared with results obtained using standard kernels (Squared Exponential and Neural Network), and compared to traversability estimation made over terrain models built using state-of-the-art GP techniques.

Knowledge unlatched : encouraging innovation in academic publishing through collective action and Open Access licensing

This case study examines the way in which Knowledge Unlatched is combining collective action and open access licenses to encourage innovation in markets for specialist academic books. Knowledge Unlatched is a not for profit organisation that has been established to help a global community of libraries coordinate their book purchasing activities more effectively and, in so doing, to ensure that books librarians select for their own collections become available for free for anyone in the world to read. The Knowledge Unlatched model is an attempt to re-coordinate a market in order to facilitate a transition to digitally appropriate publishing models that include open access. It offers librarians an opportunity to facilitate the open access publication of books that their own readers would value access to. It provides publishers with a stable income stream on titles selected by libraries, as well as an ability to continue selling books to a wider market on their own terms. Knowledge Unlatched provides a rich case study for researchers and practitioners interested in understanding how innovations in procurement practices can be used to stimulate more effective, equitable markets for socially valuable products.

Representations for evolutionary design modelling

This research looked at using the metaphor of biological evolution as a way of solving architectural design problems. Drawing from fields such as language grammars, algorithms and cellular biology, this thesis looked at ways of encoding design information for processing. The aim of this work is to help in the building of software that support the architectural design process and allow designers to examine more variations.

Representations of foreign places outside the news : an analysis of Australian newspaper travel sections

Despite continued growth over recent decades, travel journalism has so far gained little attention in journalism research, with scholars often ridiculing it and other forms of lifestyle journalism as not being real journalism. This paper aims to the shift the focus by arguing that non-news journalism is increasingly important as a site for research. It reports the results from a content analysis of Australian newspaper travel sections and examines the role they play in mediating foreign places. The results demonstrate that travel stories can be mostly classed as service stories in that they focus on destinations which are already popular with Australians. At the same time they report very little about local cultures at the destinations, demonstrating a focus on the tourist experience and a missed opportunity for improving inter-cultural understanding. A visual analysis of photographs shows stereotypical portrayals of destinations broadly in line with tourism promotion materials.

The idea of women : representations of power in the work of Charles Bukowski

This thesis is a comparative textual analysis of Charles Bukowski's representations of power in relation to the idea of women. The exegesis explores Bukowski's idea of women and power as exemplified by the representational differences between his short stories for Hustler Magazine and his novel Women. The creative piece, a novel, "Many a Broken Hearted Woman" informed and was informed by this research.

‘Redstone is like electricity’: Children's performative representations in and around Minecraft

In this article, we investigate eight and nine year old girls’ school and home use of the popular game Minecraft and the ways in which the girls ‘bring themselves into being’ through talk and digital production in the social spaces of the classroom and within the game’s multiplayer online world. This work was conducted as part of a broader digital games in education project involving primary and secondary school-aged students in Australia and focuses specifically on data collected from an all-girls primary school in Brisbane. We investigate the processes of identity construction that occur as the girls undertake practices of curatorship (Potter, 2012) to display their knowledge of Minecraft through discussion of the game, both ‘in world’ and in face-to-face interactions, and as they assemble resources within and around the game to design, build and display their creations and share stories about their game play. The article begins with a consideration of recent scholarship focussing on children, learning and digital culture and literacy practices before explaining how Minecraft is, in many ways, an exemplary instance of a digital game that promotes and enables complex practices of digital participation. We then introduce the concepts of performativity and recognition (Butler 1990, 2004, 2005) which, we argue, provide productive ways to theorise identity work within affinity groups. The article then outlines some background to the research project and our methodology before providing analysis of the data in the second half of the article. We conclude by outlining the implications of our investigation for the conceptualisation of learning spaces as affinity groups and for considering digital participation as curatorship.

Cork as canvas : exploring intersections of citizenship and collective memory in the Shandon Big Wash Up murals

Urban space has the potential to shape people's experience and understanding of the city and of the culture of a place. In some respects, murals and allied forms of wall art occupy the intersection of street art and public art; engaging, and sometimes, transforming the urban space in which they exist and those who use it. While murals are often conceived as a more ‘permanent’ form of painted art there has been a trend in recent years towards more deliberately transient forms of wall art such as washed-wall murals and reverse graffiti. These varying forms of public wall art are embedded within the fabric of the urban space and history. This paper will explore the intersection of public space, public art and public memory in a mural project in the Irish city of Cork. Focussing on the washed-wall murals of Cork's historic Shandon district, we explore the sympathetic and synergetic relationship of this wall art with the heritage architecture of the built environment and of the murals as an expression of and for the local community, past and present. Through the Shandon Big Wash Up murals we reflect on the function of participatory public art as an explicit act of urban citizenship which works to support community-led re-enchantment in the city through a reconnection with its past.

The relevance of shared experiences : a multi-level study of collective efficacy as a moderator of job control in the stressor-strain relationship

Karasek's Job Demand-Control model proposes that control mitigates the positive effects of work stressors on employee strain. Evidence to date remains mixed and, although a number of individual-level moderators have been examined, the role of broader, contextual, group factors has been largely overlooked. In this study, the extent to which control buffered or exacerbated the effects of demands on strain at the individual level was hypothesized to be influenced by perceptions of collective efficacy at the group level. Data from 544 employees in Australian organizations, nested within 23 workgroups, revealed significant three-way cross-level interactions among demands, control and collective efficacy on anxiety and job satisfaction. When the group perceived high levels of collective efficacy, high control buffered the negative consequences of high demands on anxiety and satisfaction. Conversely, when the group perceived low levels of collective efficacy, high control exacerbated the negative consequences of high demands on anxiety, but not satisfaction. In addition, a stress-exacerbating effect for high demands on anxiety and satisfaction was found when there was a mismatch between collective efficacy and control (i.e. combined high collective efficacy and low control). These results provide support for the notion that the stressor-strain relationship is moderated by both individual- and group-level factors.