Automatic object segmentation of unstructured scenes using colour and depth maps

This study presents a segmentation pipeline that fuses colour and depth information to automatically separate objects of interest in video sequences captured from a quadcopter. Many approaches assume that cameras are static with known position, a condition which cannot be preserved in most outdoor robotic applications. In this study, the authors compute depth information and camera positions from a monocular video sequence using structure from motion and use this information as an additional cue to colour for accurate segmentation. The authors model the problem similarly to standard segmentation routines as a Markov random field and perform the segmentation using graph cuts optimisation. Manual intervention is minimised and is only required to determine pixel seeds in the first frame which are then automatically reprojected into the remaining frames of the sequence. The authors also describe an automated method to adjust the relative weights for colour and depth according to their discriminative properties in each frame. Experimental results are presented for two video sequences captured using a quadcopter. The quality of the segmentation is compared to a ground truth and other state-of-the-art methods with consistently accurate results.

Career-path analysis using optimal matching and self-organizing maps

This paper is devoted to the analysis of career paths and employability. The state-of-the-art on this topic is rather poor in methodologies. Some authors propose distances well adapted to the data, but are limiting their analysis to hierarchical clustering. Other authors apply sophisticated methods, but only after paying the price of transforming the categorical data into continuous, via a factorial analysis. The latter approach has an important drawback since it makes a linear assumption on the data. We propose a new methodology, inspired from biology and adapted to career paths, combining optimal matching and self-organizing maps. A complete study on real-life data will illustrate our proposal.

Vision-only autonomous navigation using topometric maps

This paper presents a mapping and navigation system for a mobile robot, which uses vision as its sole sensor modality. The system enables the robot to navigate autonomously, plan paths and avoid obstacles using a vision based topometric map of its environment. The map consists of a globally-consistent pose-graph with a local 3D point cloud attached to each of its nodes. These point clouds are used for direction independent loop closure and to dynamically generate 2D metric maps for locally optimal path planning. Using this locally semi-continuous metric space, the robot performs shortest path planning instead of following the nodes of the graph --- as is done with most other vision-only navigation approaches. The system exploits the local accuracy of visual odometry in creating local metric maps, and uses pose graph SLAM, visual appearance-based place recognition and point clouds registration to create the topometric map. The ability of the framework to sustain vision-only navigation is validated experimentally, and the system is provided as open-source software.

Count-min sketches for estimating password frequency within Hamming distance two

The count-min sketch is a useful data structure for recording and estimating the frequency of string occurrences, such as passwords, in sub-linear space with high accuracy. However, it cannot be used to draw conclusions on groups of strings that are similar, for example close in Hamming distance. This paper introduces a variant of the count-min sketch which allows for estimating counts within a specified Hamming distance of the queried string. This variant can be used to prevent users from choosing popular passwords, like the original sketch, but it also allows for a more efficient method of analysing password statistics.

In the shadow of the enlightenment : Le Corbusier, Le Faisceau and Georges Valois

On 9 January 1927 Le Corbusier materialised on the front cover of the Faisceau journal edited by Georges Valois Le Nouveau Siècle which printed the single-point perspective of Le Corbusier’s Plan Voisin and an extract from the architect’s discourse in Urbanisme. In May Le Corbusier presented slides of his urban designs at a fascist rally. These facts have been known ever since the late 1980s when studies emerged in art history that situated Le Corbusier’s philosophy in relation to the birth of twentieth-century fascism in France—an elision in the dominant reading of Le Corbusier’s philosophy, as a project of social utopianism, whose received genealogy is Saint-Simon and Charles Fourier. Le Corbusier participated with the first group in France to call itself fascist, Valois’s militant Faisceau des Combattants et Producteurs, the “Blue Shirts,” inspired by the Italian “Fasci” of Mussolini. Thanks to Mark Antliff, we know the Faisceau did not misappropriate Le Corbusier’s plans, in some remote quasi-symbolic sense, rather Valois’s organisation was premised on the redesign of Paris based on Le Corbusier’s schematic designs. Le Corbusier’s Urbanisme was considered the “prodigious” model for the fascist state Valois called La Cité Française – after his mentor the anarcho-syndicalist Georges Sorel. Valois stated that Le Corbusier’s architectural concepts were “an expression of our profoundest thoughts,” the Faisceau, who “saw their own thought materialized” on the pages of Le Corbusier’s plans. The question I pose is, In what sense is Le Corbusier’s plan a complete representation of La Cité? For Valois, the fascist city “represents the collective will of La Cité” invoking Enlightenment philosophy, operative in Sorel, namely Rousseau, for whom the notion of “collective will” is linked to the idea of political representation: to ‘stand in’ for someone or a group of subjects i.e. the majority vote. The figures in Voisin are not empty abstractions but the result of “the will” of the “combatant-producers” who build the town. Yet, the paradox in anarcho-syndicalist anti-enlightenment thought – and one that became a problem for Le Corbusier – is precisely that of authority and representation. In Le Corbusier’s plan, the “morality of the producers” and “the master” (the transcendent authority that hovers above La Cité) is lattened into a single picture plane, thereby abolishing representation. I argue that La Cité pushed to the limits of formal abstraction by Le Corbusier thereby reverts to the Enlightenment myth it first opposed, what Theodor Adorno would call the dialectic of enlightenment.

Shadow boxing with an imaginary enemy : a response to "Law and Order Blues"

In our rejoinder to Don Weatherburn's paper,"Law and Order Blues", we do not take issue with his advocacy of the need to take crime seriously and to foster a more rational approach to the problems it poses. Where differences do emerge is (1) with his claim that he is willing to do so whilst we (in our different ways) are not; and (2) on the question of what this involves. Of particular concern is the way in which his argument proceeds by a combination of simple misrepresentation of the positions it seeks to disparage, and silence concerning issues of real substance where intellectual debate and exchange would be welcome and useful. Our paper challenges, in turn, the misrepresentation of Indermaur's analysis of trends in violent crime, the misrepresentation of Hogg and Brown's Rethinking Law and Order, the misrepresentation of the findings of some of the research into the effectiveness of punitive policies and the silence on sexual assault in "Law and Order Blues". We suggest that his silence on sexual assault reflects a more widespread unwillingness to acknowledge the methodological problems that arise in the measurement of crime because such problems severely limit the extent to which confident assertions can be made about prevalence and trends.

Augmenting traversability maps with ultra-wideband radar to enhance obstacle detection in vegetated environments

Operating in vegetated environments is a major challenge for autonomous robots. Obstacle detection based only on geometric features causes the robot to consider foliage, for example, small grass tussocks that could be easily driven through, as obstacles. Classifying vegetation does not solve this problem since there might be an obstacle hidden behind the vegetation. In addition, dense vegetation typically needs to be considered as an obstacle. This paper addresses this problem by augmenting probabilistic traversability map constructed from laser data with ultra-wideband radar measurements. An adaptive detection threshold and a probabilistic sensor model are developed to convert the radar data to occupancy probabilities. The resulting map captures the fine resolution of the laser map but clears areas from the traversability map that are induced by obstacle-free foliage. Experimental results validate that this method is able to improve the accuracy of traversability maps in vegetated environments.

Shadow boxing with an imaginary enemy : a response to “law and order blues”

In our rejoinder to Don Weatherburn's paper, “Law and Order Blues”, we do not take issue with his advocacy of the need to take crime seriously and to foster a more rational approach to the problems it poses. Where differences do emerge is (1) with his claim that he is willing to do so whilst we (in our different ways) are not; and (2) on the question of what this involves. Of particular concern is the way in which his argument proceeds by a combination of simple misrepresentation of the positions it seeks to disparage, and silence concerning issues of real substance where intellectual debate and exchange would be welcome and useful. Our paper challenges, in turn, the misrepresentation of Indermaur's analysis of trends in violent crime, the misrepresentation of Hogg and Brown's Rethinking Law and Order, the misrepresentation of the findings of some of the research into the effectiveness of punitive policies and the silence on sexual assault in “Law and Order Blues”. We suggest that his silence on sexual assault reflects a more widespread unwillingness to acknowledge the methodological problems that arise in the measurement of crime because such problems severely limit the extent to which confident assertions can be made about prevalence and trends.

The greatest shadow on Earth

In a total solar eclipse, the Moon completely covers the Sun, casting a shadow several hundred km wide across the face of the Earth. This paper describes observations of the 14 November 2012 total eclipse of the Sun visible from north Queensland, Australia. The edge of the umbra was captured on video during totality, and this video is provided for teaching purposes. A series of simple 'kitchen' experiments are described which demonstrate the 'sunset' effect seen on the horizon during a total solar eclipse and also the curved umbra seen in the sky when the eclipsed Sun is relatively close to the horizon.

Reconstruction of the ancestral marsupial karyotype from comparative gene maps

BACKGROUND: The increasing number of assembled mammalian genomes makes it possible to compare genome organisation across mammalian lineages and reconstruct chromosomes of the ancestral marsupial and therian (marsupial and eutherian) mammals. However, the reconstruction of ancestral genomes requires genome assemblies to be anchored to chromosomes. The recently sequenced tammar wallaby (Macropus eugenii) genome was assembled into over 300,000 contigs. We previously devised an efficient strategy for mapping large evolutionarily conserved blocks in non-model mammals, and applied this to determine the arrangement of conserved blocks on all wallaby chromosomes, thereby permitting comparative maps to be constructed and resolve the long debated issue between a 2n=14 and 2n=22 ancestral marsupial karyotype. RESULTS: We identified large blocks of genes conserved between human and opossum, and mapped genes corresponding to the ends of these blocks by fluorescence in situ hybridization (FISH). A total of 242 genes was assigned to wallaby chromosomes in the present study, bringing the total number of genes mapped to 554 and making it the most densely cytogenetically mapped marsupial genome. We used these gene assignments to construct comparative maps between wallaby and opossum, which uncovered many intrachromosomal rearrangements, particularly for genes found on wallaby chromosomes X and 3. Expanding comparisons to include chicken and human permitted the putative ancestral marsupial (2n=14) and therian mammal (2n=19) karyotypes to be reconstructed. CONCLUSIONS: Our physical mapping data for the tammar wallaby has uncovered the events shaping marsupial genomes and enabled us to predict the ancestral marsupial karyotype, supporting a 2n=14 ancestor. Futhermore, our predicted therian ancestral karyotype has helped to understand the evolution of the ancestral eutherian genome.

In the shadow of the welfare state : the role of payday lending in poverty survival in Australia

A defining characteristic of contemporary welfare governance in many western countries has been a reduced role for governments in direct provision of welfare, including housing, education, health and income support. One of the unintended consequences of devolutionary trends in social welfare is the development of a ‘shadow welfare state’ (Fairbanks, 2009; Gottschalk, 2000), which is a term used to describe the complex partnerships between statebased social protection, voluntarism and marketised forms of welfare. Coupled with this development, conditional workfare schemes in countries such as the United States, Canada, the UK and Australia are pushing more people into informal and semi-formal means of poverty survival (Karger, 2005). These transformations are actively reshaping welfare subjectivities and the role of the state in urban governance. Like other countries such as the US, Canada and the UK, the fringe lending sector in Australia has experienced considerable growth over the last decade. Large numbers of people on low incomes in Australia are turning to non-mainstream financial services, such as payday lenders, for the provision of credit to make ends meet. In this paper, we argue that the use of fringe lenders by people on low incomes reveals important theoretical and practical insights into the relationship between the mixed economy of welfare and the mixed economy of credit in poverty survival.

Linkage maps in pea

We have analyzed segregation patterns of markers among the late generation progeny of several crosses of pea. From the patterns of association of these markers we have deduced linkage orders. Salient features of these linkages are discussed, as is the relationship between the data presented here and previously published genetic and cytogenetic data.

Minimum cost of transport in human running is not ubiquitous

Purpose This study explores recent claims that humans exhibit a minimum cost of transport (CoTmin) for running which occurs at an intermediate speed, and assesses individual physiological, gait and training characteristics. Methods Twelve healthy participants with varying levels of fitness and running experience ran on a treadmill at six self-selected speeds in a discontinuous protocol over three sessions. Running speed (km[middle dot]hr-1), V[spacing dot above]O2 (mL[middle dot]kg-1[middle dot]km-1), CoT (kcal[middle dot]km-1), heart rate (beats[middle dot]min-1) and cadence (steps[middle dot]min-1) were continuously measured. V[spacing dot above]O2 max was measured on a fourth testing session. The occurrence of a CoTmin was investigated and its presence or absence examined with respect to fitness, gait and training characteristics. Results Five participants showed a clear CoTmin at an intermediate speed and a statistically significant (p < 0.05) quadratic CoT-speed function, while the other participants did not show such evidence. Participants were then categorized and compared with respect to the strength of evidence for a CoTmin (ClearCoTmin and NoCoTmin). The ClearCoTmin group displayed significantly higher correlation between speed and cadence; more endurance training and exercise sessions per week; than the NoCoTmin group; and a marginally non-significant but higher aerobic capacity. Some runners still showed a CoTmin at an intermediate speed even after subtraction of resting energy expenditure. Conclusion The findings confirm the existence of an optimal speed for human running, in some but not all participants. Those exhibiting a COTmin undertook a higher volume of running, ran with a cadence that was more consistently modulated with speed, and tended to be aerobically fitter. The ability to minimise the energetic cost of transport appears not to be ubiquitous feature of human running but may emerge in some individuals with extensive running experience.

Shared generation of pseudo-random functions with cumulative maps

In Crypto’95, Micali and Sidney proposed a method for shared generation of a pseudo-random function f(·) among n players in such a way that for all the inputs x, any u players can compute f(x) while t or fewer players fail to do so, where 0 ≤ t < u ≤ n. The idea behind the Micali-Sidney scheme is to generate and distribute secret seeds S = s1, . . . , sd of a poly-random collection of functions, among the n players, each player gets a subset of S, in such a way that any u players together hold all the secret seeds in S while any t or fewer players will lack at least one element from S. The pseudo-random function is then computed as where f s i (·)’s are poly-random functions. One question raised by Micali and Sidney is how to distribute the secret seeds satisfying the above condition such that the number of seeds, d, is as small as possible. In this paper, we continue the work of Micali and Sidney. We first provide a general framework for shared generation of pseudo-random function using cumulative maps. We demonstrate that the Micali-Sidney scheme is a special case of this general construction.We then derive an upper and a lower bound for d. Finally we give a simple, yet efficient, approximation greedy algorithm for generating the secret seeds S in which d is close to the optimum by a factor of at most u ln 2.

Experience has no shadow

This research is situated in the field of practice-led research investigating embodied perspectives on the performance of dance making. In the stock of choreographic literature, the celebrated ‘creativity’ label is associated predominantly with the choreographer and is discussed in terms of product rather than process (Lussier-Ley and Durand-Bush 2009; Hennessey 2003). A reliance on the mystery of inspiration or choreographic genius (Penty 1998) for the production of ‘great’ dance works does not acknowledge the complex and timely process common in the creation of dance (Mace and Ward 2002) nor provide a true representation of the creative contributors (Farrer 2014). The failure to attribute creative impulses and skills to dancers is reminiscent of a time when they were thought of only as instruments in the creative process not active participants and collaborators (Jowitt 2001a; H’Doubler 1957). This project asked the question, to what end do dancers contribute to choreography and how is this contribution valued and recognised? Dancers are integral to the creative process. The research found that the scope of a dancers’ creative involvement in the development of a new work is dependent on: the individual choreographers approach to creating movement; the relationship between dancer and choreographer, and dancer and fellow company members; and the dancers collaborative skills and interpretive skills, versatility, and initiative. Recognition and attribution of dancers’ creative input is dependent on a choreographer’s viewpoint, generosity, and prior creative experiences. The work was created as a part of the Ausdance Queensland 2010 Bell Tower III Choreographic Residency program. Applicants were peer reviewed and vetted by a panel of local and national dance producers. The creative work was presented at the Judith Wright Centre for Live Arts. The project was funded by Ausdance Queensland and Arts Queensland. https://es-es.facebook.com/events/106661226023025/?hc_location=stream