Chancellery

Operability analysis of nonlinear processes based on incremental dissipativity

Henry Santoso et al. — Thu, 30 Aug 2012 20:00:35 PDT

Process operability can be defined as the ability of a process to reject disturbances at a specified operating point and/or to move quickly and smoothly from one operating point to another operating point using a feedback control system. Unlike linear processes, the properties of nonlinear processes (e.g., stability, minimum phase condition, etc.) are different around different equilibria. Most existing operability analysis for nonlinear systems focuses on one particular operating point of interest. This paper addresses the issues of dynamic process operability at various operating points, including the reachability of all equilibrium points or output trajectories in an operating region, regardless of initial conditions. In this work, a nonlinear analysis approach is developed based on the concept of incremental stability. Conditions for incremental stability are derived based on incremental dissipativity. The links between input and output multiplicities and incremental dissipativity are explored. The dynamic control performance achievable in terms of the speed of the response of the closed-loop system and offset minimization is studied. A method for determination of incremental dissipativity using Linear Differential Inclusion (LDI) is also presented, to facilitate the dissipativity based operability analysis.

Ontogenetic behaviour and swimming ability of the endangered eastern freshwater cod, Maccullochella ikei, with notes on growth and development

Gavin L. Butler et al. — Thu, 30 Aug 2012 20:00:33 PDT

Understanding the larval ecology of individual fish species is fundamental in ensuring their long-term conservation. The endangered eastern freshwater cod, Maccullochella ikei, is endemic to the Clarence and Richmond River systems of north-eastern New South Wales, Australia. Little is known about the behaviour of larval M. ikei in the wild, particularly before and after the swim-up stage, and following dispersal from the nest site. The aims of this study were to quantify the swimming ability, depth selection, light preference and substrate selection of hatchling to day-30 M. ikei under controlled laboratory conditions, and to describe its growth and development over the same period. Maccullochella ikei larvae grew constantly but not consistently during the experiment. Exogenous feeding commenced around day 12, prior to the full exhaustion of the yolk. Maximal swimming ability improved daily, but maximum swimming speed declined significantly between days 12 and 13 and remained low. Maccullochella ikei larvae were initially photonegative but were positively phototactic by day 10. Depth selection was for the benthos until day 8, beyond which time larvae dispersed to all depths when released. Substrate selection was for sand in younger larvae but changed to upstream substrates as the experiment progressed. The results of the current study suggest that the period between day 10 and day 20 is critical in the early ontogeny of M. ikei, when it switched phototrophic behaviour, transitioned from endogenous to exogenous feeding and experienced a decline in swimming ability.

Abundance of East coast Australian humpback whales (Megaptera novaeangliae) in 2005 estimated using multi-point sampling and capture recapture analysis

David A. Paton et al. — Thu, 30 Aug 2012 20:00:32 PDT

The humpback whales (Megaptera novaeangliae) that migrate along the east coast of Australia were hunted to near extinction during the last century. This remnant population is part of Breeding Stock E. Previous abundance estimates for the east Australian portion of Breeding Stock E have been based mainly on land based counts. Here we present a capture-recapture abundance estimate for this population using photo identification data. These data were collected at three locations on the migration route (Byron Bay – northern migration, Hervey Bay and Ballina - southern migration) in order to estimate the population of humpback whales that migrated along the east coast of Australia in 2005. The capture-recapture data were analysed using a variety of closed population models with a model-averaged estimate of 7041 (4075 –10008 95% C.I.) whales.

Patterns of alcohol and other drug use associated with major depression among gay men attending general practices in Australia

Martin Holt et al. — Thu, 30 Aug 2012 19:04:25 PDT

Our aim was to clarify the role of alcohol and other drug (AOD) use in major depression among gay men attending general medical practices. A secondary analysis was conducted on survey data collected from 531 gay men attending high-HIV-caseload general practices in Adelaide and Sydney, Australia. The survey contained demographic, social, behavioural and AOD variables. Participants were classified into those with (n = 130) and without major depression (n = 401) using the PHQ-9 screening tool. Although rates of drug use were very high in the sample, multivariate logistic regression analysis showed that the majority of variables independently associated with major depression were social and behavioural factors. Only one AOD variable was associated with major depression: the use of three or more drug types in the past 6 months. Attending to specific patterns of AOD use may assist in the identification of gay men most at risk of major depression.

Unstraightening: ethical adventures with queer heterosexuality in an open text

Nollie Nahrung — Thu, 30 Aug 2012 19:04:24 PDT

Charlie Rich sang that ‘no-one knows what goes on behind closed doors’. And with the (normatively bedroom) doors firmly shut, the heteronormative privilege to privacy is invoked, drawing the doona of homogeneity over heterosexuality. Yet what may be gained from opening closed doors from the inside? Abstract: Ethical writing considerations will be explored in the context of why, through the creation of an autoethnographic text for my Honours research project, I have decided to reject the privilege of privacy to examine my lived experience of heterosexual polyamory. This discussion will engage with the productive debates surrounding queer heterosexuality to explore the possibilities and limitations of writing against normativity while simultaneously holding a position of heterosexual privilege. In doing so, this paper will consider how the construction of an open text, that includes tools (scalpel and pencil) and spaces (blank right hand pages) for the reader to respond, may acknowledge the limitations of speaking about the self by opening the project to other voices and experiences. It will outline how the construction of such a text supports a belief that autoethnography holds significant potential to promote research as dialogue, or conversation. Yet, through constructing a text as the site of intended reciprocal exchange, what are the ethics of placing both author and reader in positions that may prove unfamiliar and perhaps uncomfortable?

Australian franchising research: review, synthesis and future research directions

Owen Wright et al. — Thu, 30 Aug 2012 19:04:22 PDT

This article represents a brief history of the development of franchising in Australia and its regulatory framework and links this to an analysis of relevant research. Findings indicate a disparate ad hoc approach to research including scoping studies at the embryonic stage of franchise development; significant evidence of census style research culminating in a trajectory of disparate studies utilising more sophisticated research methods. For franchising research to advance there appears to be a need to interface with other research domains in SME and entrepreneurship research, extend the range of issues which are the subject of franchising research: begin longitudinal studies in order to better understand change over time; promote studies which have a sectoral focus in order to improve knowledge and understanding at that level of analysis; and. increase the representation of cross-border/cultural research in the volume of work being undertaken.

Using the concept of resilience to explain entrepreneurial success in China

Jing Sun et al. — Thu, 30 Aug 2012 19:04:21 PDT

This paper aims (1) to explore resilience among Chinese entrepreneurs and its correlation with entrepreneurial types; (2) to examine the relationship between entrepreneurial type and other factors including locus of control, education and experience. A cross-sectional cohort study design was used. Fifty thousand entrepreneurs were randomly selected from 228 cities across 31 provinces in China, of which 38,890 agreed to participate in this study. Results indicated that entrepreneurs who founded a resource-based business had higher resilience scores than those who founded risk or knowledge-based ventures. The resource-based and skill-based entrepreneurs were similar to each other in terms of creativity and innovation, need for achievement, flexibility and knowledge seeking. The findings of this study suggest that institutions and small business support agencies need to provide training opportunities for entrepreneurs to develop resilience characteristics before they commence establishing business ventures.

Lost or just at a crossroads: is entrepreneurship the way forward for marketing?

Andrew McAuley — Thu, 30 Aug 2012 19:04:19 PDT

Purpose – The purpose of this paper is to reflect on whether entrepreneurship is the way forward for marketing.

Design/methodology/approach – The approach is to reflect on work undertaken in the area and to make some additional contemporary observations.

Findings – Together, both entrepreneurship and marketing offer the opportunity to develop unique and tailored solutions to consumers' needs and wants.

Originality/value – This viewpoint has value in its contribution to stimulating thinking and debate about future directions for research.

Quality assurance in Australian higher education: historical and future development

Mahsood Shah et al. — Tue, 28 Aug 2012 00:15:14 PDT

Higher education policies related to quality assurance are implemented in many countries. The purposes of such policies are to ensure the provision for high-quality education, university accountability and transparency in the use of public funding and meeting the needs of the diverse stakeholders. The current Australian Higher Education Quality Assurance Framework was implemented in the year 2000. It can be described that the framework has been enjoyed by universities, academics and other providers in Australia. This paper provides a brief history of quality assurance, its evolution in higher education in Australia and current changes and trends in quality assurance in other developed countries. It then provides an analysis of the success and deficiencies of the current framework used in Australia and suggestions which may be helpful in the development of the new framework. The analysis includes the thoughts of the three authors based on their experience in managing quality and reviews in seven different institutions and the views of more than 40 participants who are staff members from 25 Australian universities.

Low energy super-elastic scattering studies of calcium over the complete angular range using a magnetic angle changing device

Martyn Hussey et al. — Wed, 30 Jul 2008 14:29:34 PDT

Super-elastic scattering processes can be considered as the ‘time reversal’ of electron–photon coincidence measurements, with the advantage that data are accumulated thousands of times faster. This allows a far more extensive and accurate study of electron excitation of atoms which can also be excited using laser radiation. The application of a newly invented magnetic angle changing (MAC) device to these experiments has allowed the complete scattering geometry to be accessed for the first time, and experimental methods adopted in these new experiments are discussed here. Data are presented for excitation of the 4¹P₁ state of calcium by electron impact at scattering angles from near 0 degrees to beyond 180 degrees, with incident energies of 45 eV and 55 eV. The results are compared to the DWBA theory of Stauffer and colleagues, with generally excellent agreement.

Theoretical modeling of resonant laser excitation of atoms in a magnetic field

Andrew James Murray et al. — Wed, 30 Jul 2008 04:02:40 PDT

The interaction of near-resonant laser radiation with atoms immersed in a magnetic B field is calculated using a quantum electrodynamic model. In this model, the magnetic field is assumed to produce a small perturbation such that the degeneracy of the magnetic substates is lifted while maintaining the usual quantum numbers that define the states (the Zeeman effect). The laser radiation is considered to have a narrow bandwidth and to be temporally and spatially coherent. The model produces three general coupled differential equations that describe the state populations and their relative coherences and the optical coherences between levels coupled by the laser radiation. The model can therefore be directly applied to different experiments ranging from atom trapping and cooling experiments through to collision experiments carried out in magnetic and laser fields.

Superelastic electron scattering within a magnetic angle changer: determination of the angular momentum transferred during electron excitation over all scattering angles

Martyn Hussey et al. — Fri, 25 Jul 2008 03:56:32 PDT

By utilising super-elastic electron scattering from laser excited atoms together with a new Magnetic Angle Changing device, it is possible to determine the differential cross sections for excitation of atoms by electron impact over the complete scattering geometry. In the experiments described here, these techniques are combined to reveal the angular momentum transferred to calcium atoms during electron excitation to the 4¹P₁ state, from near zero degrees to beyond 180 degrees for the first time. The results significantly extend all previous data, and are compared to calculations based on a distorted wave Born approximation by Stauffer and colleagues. The experimental techniques are discussed, and results are presented for electron energies of 45eV and 55eV.