Speckle reduction in optical coherence tomography imaging by affine-motion image registration

Signal-degrading speckle is one factor that can reduce the quality of optical coherence tomography images. We demonstrate the use of a hierarchical model-based motion estimation processing scheme based on an affine-motion model to reduce speckle in optical coherence tomography imaging, by image registration and the averaging of multiple B-scans. The proposed technique is evaluated against other methods available in the literature. The results from a set of retinal images show the benefit of the proposed technique, which provides an improvement in signal-to-noise ratio of the square root of the number of averaged images, leading to clearer visual information in the averaged image. The benefits of the proposed technique are also explored in the case of ocular anterior segment imaging.

How to pick a fight : Visualisation and sharing in catastrophic times

In a post September 11 era “the fight”, as a cultural construct, could hardly be more pertinent. We are seemingly forever poised on the edge of controversial U.S. led attacks on wayward Middle Eastern states and unexamined oppositions between the concepts of ‘good’ and ‘evil’ are evoked as valid justifications for battle. Our leaders muster us into wars of vigilance and national cohesion against unseen, unknown and uncomprehended terrorists hiding where communists once lurked under our beds. The articles in this issue examine fights in terms of media strategies and cultural divides in a range of contexts.

Joined-up governance in Australia : how the past can inform the future

Joined-up enterprises have become a cornerstone of the institutional architecture to facilitate closer linkages within and between departments and across sectors. Some of these initiatives are now mainstream enterprises, while others struggled to gain purchase or effect. Since the future is likely to be characterized by an ongoing emphasis on joined-up initiatives, an assessment of past efforts can provide a valuable backdrop for the development of new approaches and the fine tuning of existing ones. Drawing on ten years of research data, this article tracks the ebbs and flows of joined-up or integrated practice in Queensland. In doing so, it examines the drivers for integration, preferred models, and the language used to engender change. It also assesses what has worked and why and whether integrated reform has been sustained. Based on these insights, an extended integration framework is presented, which will assist those responsible for the design, monitoring, and evaluation of joined-up processes.

Apps and attitudes : towards an understanding of the m-librarian’s professional make-up

This chapter will discuss a research project that identifies the skills, knowledge and attitudes of the m-librarian. Six library and information professionals engaged in the provision of m-library services throughout Australia were interviewed. Six themes emerged as being critical for the m-librarian: technology, personal traits, user focus, communication, collaboration, research and development. The research is significant because it establishes an open dialogue between current industry professionals, library science educators and the professional association on the evolving skills and knowledge required by information professional in a world of rapidly changing technology. This dialogue will guide the development of current and future education of library and information professionals.

Fiber Bragg Grating sensors for railway systems

Fiber Bragg grating (FBG) sensor technology has been attracting substantial industrial interests for the last decade. FBG sensors have seen increasing acceptance and widespread use for structural sensing and health monitoring applications in composites, civil engineering, aerospace, marine, oil & gas, and smart structures. One transportation system that has been benefitted tremendously from this technology is railways, where it is of the utmost importance to understand the structural and operating conditions of rails as well as that of freight and passenger service cars to ensure safe and reliable operation. Fiberoptic sensors, mostly in the form of FBGs, offer various important characteristics, such as EMI/RFI immunity, multiplexing capability, and very long-range interrogation (up to 230 km between FBGs and measurement unit), over the conventional electrical sensors for the distinctive operational conditions in railways. FBG sensors are unique from other types of fiber-optic sensors as the measured information is wavelength-encoded, which provides self-referencing and renders their signals less susceptible to intensity fluctuations. In addition, FBGs are reflective sensors that can be interrogated from either end, providing redundancy to FBG sensing networks. These two unique features are particularly important for the railway industry where safe and reliable operations are the major concerns. Furthermore, FBGs are very versatile and transducers based on FBGs can be designed to measure a wide range of parameters such as acceleration and inclination. Consequently, a single interrogator can deal with a large number of FBG sensors to measure a multitude of parameters at different locations that spans over a large area.

Monte Carlo verification of gel dosimetry measurements for stereotactic radiotherapy

The quality assurance of stereotactic radiotherapy and radiosurgery treatments requires the use of small-field dose measurements that can be experimentally challenging. This study used Monte Carlo simulations to establish that PAGAT dosimetry gel can be used to provide accurate, high resolution, three-dimensional dose measurements of stereotactic radiotherapy fields. A small cylindrical container (4 cm height, 4.2 cm diameter) was filled with PAGAT gel, placed in the parietal region inside a CIRS head phantom, and irradiated with a 12 field stereotactic radiotherapy plan. The resulting three-dimensional dose measurement was read out using an optical CT scanner and compared with the treatment planning prediction of the dose delivered to the gel during the treatment. A BEAMnrc DOSXYZnrc simulation of this treatment was completed, to provide a standard against which the accuracy of the gel measurement could be gauged. The three dimensional dose distributions obtained from Monte Carlo and from the gel measurement were found to be in better agreement with each other than with the dose distribution provided by the treatment planning system's pencil beam calculation. Both sets of data showed close agreement with the treatment planning system's dose distribution through the centre of the irradiated volume and substantial disagreement with the treatment planning system at the penumbrae. The Monte Carlo calculations and gel measurements both indicated that the treated volume was up to 3 mm narrower, with steeper penumbrae and more variable out-of-field dose, than predicted by the treatment planning system. The Monte Carlo simulations allowed the accuracy of the PAGAT gel dosimeter to be verified in this case, allowing PAGAT gel to be utilised in the measurement of dose from stereotactic and other radiotherapy treatments, with greater confidence in the future.

Government initiative and start-up firms’ eco-innovation : A case study through the ecological modernisation lens

Government programs to finance small firms or start-ups have attracted a little empirical attention. From an economical perspective, the effect of government grants is evaluated by a measure of innovation or firm productivity. Yet, this paper takes a different approach from economical view aiming to address the research question “How do start ups firms view the relationship between government grants and their co-efficient innovation effort?” Semi-structured interviews with grant recipients (start-up business owners revealed that the grants assist firms to leverage their resource limitations but at the same time the grants also act as a major roadblock for their product development success.

Optical and microscopic study of a polymer-nanotube mixture for organic photovoltaic applications

Organic solar cells based on bulk heterojunction between a conductive polymer and a carbon nanostructure offer potential advantages compared to conventional inorganic cells. Low cost, light weight, flexibility and high peak power per unit weight are all features that can be considered a reality for organic photovoltaics. Although polymer/carbon nanotubes solar cells have been proposed, only low power conversion efficiencies have been reached without addressing the mechanisms responsible for this poor performance. The purpose of this work is therefore to investigate the basic interaction between carbon nanotubes and poly(3-hexylthiophene) in order to demonstrate how this interaction affects the performance of photovoltaic devices. The outcomes of this study are the contributions made to the knowledge of the phenomena explaining the behaviour of electronic devices based on carbon nanotubes and poly(3-hexylthiophene). In this PhD, polymer thin films with the inclusion of uniformly distributed carbon nanotubes were deposited from solution and characterised. The bulk properties of the composites were studied with microscopy and spectroscopy techniques to provide evidence of higher degrees of polymer order when interacting with carbon nanotubes. Although bulk investigation techniques provided useful information about the interaction between the polymer and the nanotubes, clear evidence of the phenomena affecting the heterojunction formed between the two species was investigated at nanoscale. Identifying chirality-driven polymer assisted assembly on the carbon nanotube surface was one of the major achievements of this study. Moreover, the analysis of the electrical behaviour of the heterojunction between the polymer and the nanotube highlighted the charge transfer responsible for the low performance of photovoltaic devices. Polymer and carbon nanotube composite-based devices were fabricated and characterised in order to study their electronic properties. The carbon nanotube introduction in the polymer matrix evidenced a strong electrical conductivity enhancement but also a lower photoconductivity response. Moreover, the extension of pristine polymer device characterisation models to composites based devices evidenced the conduction mechanisms related to nanotubes. Finally, the introduction of carbon nanotubes in the polymer matrix was demonstrated to improve the pristine polymer solar cell performance and the spectral response even though the power conversion efficiency is still too low.

Class contestations and Australia’s resource boom : the emergence of the ‘cashed-up bogan’

This article examines the figure of the ‘Cashed-up Bogan’ or ‘Cub’ in Australian media from 2006 to 2009. It explains that ‘Bogan’, like that of ‘Chav’ in Britain, is a widely engaged negative descriptor for the white working-class poor. In contrast, ‘Cubs’ have economic capital. This capital, and the Cub’s emergence, is linked to Australia’s resource boom of recent decades when the need for skilled labour allowed for a highly demarcated segment of the working class to earn relatively high incomes in the mining sector and to participate in consumption. We argue that access to economic capital has provided the Cub with mobility to enter the everyday spaces of the middle class, but this has caused disruption and anxiety to middle-class hegemony. As a result, the middle class has redrawn and reinforced class-infused symbolic and cultural boundaries, whereby, despite their wealth, pernicious media representations mark Cubs as ‘other’ to the middle-class deservingness, taste and morality.