Accurate silhouette segmentation using motion detection and graph cuts

Acquiring accurate silhouettes has many applications in computer vision. This is usually done through motion detection, or a simple background subtraction under highly controlled environments (i.e. chroma-key backgrounds). Lighting and contrast issues in typical outdoor or office environments make accurate segmentation very difficult in these scenes. In this paper, gradients are used in conjunction with intensity and colour to provide a robust segmentation of motion, after which graph cuts are utilised to refine the segmentation. The results presented using the ETISEO database demonstrate that an improved segmentation is achieved through the combined use of motion detection and graph cuts, particularly in complex scenes.

Labelled silhouettes for human pose estimation

This paper proposes a new method of using foreground silhouette images for human pose estimation. Labels are introduced to the silhouette images, providing an extra layer of information that can be used in the model fitting process. The pixels in the silhouettes are labelled according to the corresponding body part in the model of the current fit, with the labels propagated into the silhouette of the next frame to be used in the fitting for the next frame. Both single and multi-view implementations are detailed, with results showing performance improvements over only using standard unlabelled silhouettes.

Rejoinder to James Hamilton

Hamilton (2001) makes a number of comments on our paper (Harding and Pagan, 2002b). The objectives of this rejoinder are, firstly, to note the areas in which we agree; secondly, to define with greater clarity the areas in which we disagree; and, thirdly, to point to other papers, including a longer version of this response, where we have dealt with some of the issues that he raises. The core of our debate with him is whether one should use an algorithm with a specified set of rules for determining the turning points in economic activity or whether one should use a parametric model that features latent states. Hamilton begins his criticism by stating that there is a philosophical distinction between the two methods for dating cycles and concludes that the method we use “leaves vague and intuitive exactly what this algorithm is intended to measure”. Nothing is further from the truth. When seeking ways to decide on whether a turning point has occurred it is always useful to ask the question, what is a recession? Common usage suggests that it is a decline in the level of economic activity that lasts for some time. For this reason it has become standard to describe a recession as a decline in GDP that lasts for more than two quarters. Finding periods in which quarterly GDP declined for two periods is exactly what our approach does. What is vague about this?

Practice-led research and the innovation agenda : beyond the postgraduate research degree in the arts, design and media

The rise of the ‘practice-led’ research approach has given us a new way of understanding what creative practice in art, design and media can do in the academy and the world— it can materialise new ideas and forms into being as a form of experimental research. Yet, to date, attention around the world, and especially in Australia, has been chiefly directed at the postgraduate research degrees, most notably the PhD or doctoral equivalents. Recent mapping projects and surveys of practice-led research in Australia reveal much about the institutional conditions of higher degree researchers, supervisors, examiners and research training (Baker et al 2009; Evans et al 2003; Dally et al 2004; Paltridge et al 2009; Phillips et al 2009). Given this focus, we might well ask: is the practice-led approach destined to be a part of the higher degree ghetto only, or does it have an afterlife? What is the place of ‘practice-led’ beyond the postgraduate degree? After all postgraduate researchers do not remain postgraduates forever, and perhaps the practice-led approach to research may have benefits in wider university, professional and communal contexts.

La raza y la lengua como capital en las escuelas : una propuesta sociológica para las reformas en educación lingüística

Este texto hace un acercamiento sociológico al análisis de la raza y la lengua en la formación de programas de educación en idiomas. Este enfoque usa los modelos de Bourdieu de habitus y campo social, los cuales enmarcan la raza y la lengua como elementos variables en el cambio educativo y pedagógico, que están, a la vez, sujetos a la agenciamiento de profesores y estudiantes. El enfoque sugiere que una política de educación en lenguas para la justicia social puede concentrarse no sólo en el cambio y el desarrollo del sujeto humano, sino también en cambio sistemático de los campos sociales del currículo.

Effect of the Summer Months on Body Weight and Composition in College Women

BACKGROUND AND OBJECTIVES: College students and young adults are experiencing the greatest increases in rates of obesity, and 20% of college students are classified as obese. The objective of this study was to compare changes and rates of change in body weight and body composition between the freshman academic year and the summer after the freshman year among female college students. METHODS: Participants were recruited early in their freshman year of college to participate in a prospective longitudinal study examining changes in body weight and composition over the college years. Height and weight were measured, and body composition was assessed using dual energy x-ray absorptiometry (DEXA) at the beginning and end of the freshman year. Upon return from the summer for their sophomore year, participants returned to have all measurements repeated. Sixty-nine female participants completed all three visits. RESULTS: Body weight increased 1.3 kg during the academic period and an additional 0.1 kg during the summer period. Body mass index (BMI) increased between the first two visits but did not change between the last two visits. However, percent fat increased at each visit. Fat-free mass significantly increased 0.5 kg over the academic year but decreased by 1.1 kg over the summer (p<0.05). Greater rates of change were detected in percent fat, fat-free mass, and BMI during the summer compared with the academic year (p<0.05). CONCLUSIONS: Differences in body composition between the academic and summer periods may reflect changes in living situations between these periods. Unfavorable changes during the summer suggest the need to promote healthy lifestyles to freshman women before they leave campus for the summer

Engaging data-literate beginning teachers

Gen Y beginning teachers have an edge: they’ve grown up in an era of educational accountability, so when their students have to sit a high-stakes test, they can relate.

The effect of metamictization on the Raman spectroscopy of the uranyl titanate mineral davidite (La,Ce)(Y,U,Fe2+)(Ti,Fe3+)20(O,OH)38

Raman spectra of the uranyl titanate mineral davidite-(La) (La,Ce)(Y,U,Fe2+)(Ti,Fe3+)20(O,OH)38 were analysed and related to the mineral structure. Observed bands are attributed to the TiO and (UO2)2+ stretching and bending vibrations, U-OH bending vibrations, H2O and (OH)- stretching, bending and libration modes. U-O bond lengths in uranyls and O-H…O bond lengths are calculated from the wavenumbers assigned to the stretching vibrations. Raman bands of davidite-(La) are in harmony with those of the uranyl oxyhydroxides. The mineral davidite-(La) is metamict as is evidenced by the intensity of the UO stretching and bending modes being of lower intensity than expected and with bands that are significantly broader.

Researching professionals and online social networking : toward a professional doctorate

The professional doctorate is a degree that is specifically designed for professionals investigating real world problems and relevant issues for a profession, industry and/ or the community. The study on which this paper is based sought to track the scholarly skill development of a cohort of professional doctoral students who commenced their course in January 2008 at an Australian University. Via an initial survey and two focus groups held six months apart, the study aimed to determine if there had been any qualitative shifts in students’ understandings, expectations and perceptions regarding this developing knowledge and skills. Three key findings has emerged from this study were: (i) the appropriateness of using a blended learning approach for this doctoral cohort; (ii) the challenges of using wikis as an online technology of creating communities of practice: and (iii) that the transition from student to scholar is a process that is unlikely to be achieved in a short time frame.