Thomas Young's contribution to visual optics : the Bakerian lecture "On the mechanism of the eye"

Thomas Young (1773-1829) carried out major pioneering work in many different subjects. In 1800 he gave the Bakerian Lecture of the Royal Society on the topic of the “mechanism of the eye”: this was published in the following year (Young, 1801). Young used his own design of optometer to measure refraction and accommodation, and discovered his own astigmatism. He considered the different possible origins of accommodation and confirmed that it was due to change in shape of the lens rather than to change in shape of the cornea or an increase in axial length. However, the paper also dealt with many other aspects of visual and ophthalmic optics, such as biometric parameters, peripheral refraction, longitudinal chromatic aberration, depth-of-focus and instrument myopia. These aspects of the paper have previously received little attention. We now give detailed consideration to these and other less-familiar features of Young’s work and conclude that his studies remain relevant to many of the topics which currently engage visual scientists.

Innovation in construction : a case study of the Australian context

The dominant economic paradigm currently guiding industry policy making in Australia and much of the rest of the world is the neoclassical approach. Although neoclassical theories acknowledge that growth is driven by innovation, such innovation is exogenous to their standard models and hence often not explored. Instead the focus is on the allocation of scarce resources, where innovation is perceived as an external shock to the system. Indeed, analysis of innovation is largely undertaken by other disciplines, such as evolutionary economics and institutional economics. As more has become known about innovation processes, linear models, based on research and development or market demand, have been replaced by more complex interactive models which emphasise the existence of feedback loops between the actors and activities involved in the commercialisation of ideas (Manley 2003). Currently dominant among these approaches is the national or sectoral innovation system model (Breschi and Malerba 2000; Nelson 1993), which is based on the notion of increasingly open innovation systems (Chesbrough, Vanhaverbeke, and West 2008). This chapter reports on the ‘BRITE Survey’ funded by the Cooperative Research Centre for Construction Innovation which investigated the open sectoral innovation system operating in the Australian construction industry. The BRITE Survey was undertaken in 2004 and it is the largest construction innovation survey ever conducted in Australia. The results reported here give an indication of how construction innovation processes operate, as an example that should be of interest to international audiences interested in construction economics. The questionnaire was based on a broad range of indicators recommended in the OECD’s Community Innovation Survey guidelines (OECD/Eurostat 2005). Although the ABS has recently begun to undertake regular innovation surveys that include the construction industry (2006), they employ a very narrow definition of the industry and only collect very basic data compared to that provided by the BRITE Survey, which is presented in this chapter. The term ‘innovation’ is defined here as a new or significantly improved technology or organisational practice, based broadly on OECD definitions (OECD/Eurostat 2005). Innovation may be technological or organisational in nature and it may be new to the world, or just new to the industry or the business concerned. The definition thus includes the simple adoption of existing technological and organisational advancements. The survey collected information about respondents’ perceptions of innovation determinants in the industry, comprising various aspects of business strategy and business environment. It builds on a pilot innovation survey undertaken by PricewaterhouseCoopers (PWC) for the Australian Construction Industry Forum on behalf of the Australian Commonwealth Department of Industry Tourism and Resources, in 2001 (PWC 2002). The survey responds to an identified need within the Australian construction industry to have accurate and timely innovation data upon which to base effective management strategies and public policies (Focus Group 2004).

Treating an unhealthy organisational culture : the implications of the Bundaberg Hospital inquiry for managerial ethical decision making

This paper explores the interplay between individual values, espoused organisational values and the values of the organisational culture in practice in light of a recent Royal Commission in Queensland, Australia, which highlighted systematic failures in patient care. The lack of congruence among values at these levels impacts upon the ethical decision making of health managers. The presence of institutional ethics regimes such as the Public Sector Ethics Act 1994 (Qld) and agency codes of conduct are not sufficient to counteract the negative influence of informal codes of practice that undermine espoused organisational values and community standards. The ethical decision-making capacity of health care managers remains at the front line in the battle against unethical and unprofessional practice. What is known about the topic? Value congruence theory focusses on the conflicts between individual and organisational values. Congruence between individual values, espoused values and values expressed in everyday practice can only be achieved by ensuring that such shared values are an ever-present factor in managerial decision making. What does this paper add? The importance of value congruence in building and sustaining a healthy organisational culture is confirmed by the evidence presented in the Bundaberg Hospital Inquiry. The presence of strong individual values among staff and strong espoused values in line with community expectations and backed up by legislation and ethics regimes were not, in themselves, sufficient to ensure a healthy organisational culture and prevent unethical, and possibly illegal, behaviour. What are the implications for practitioners? Managers must incorporate ethics in decision making to establish and maintain the nexus between individual and organisational values that is a vital component of a healthy organisational culture.

A study of the generalised max–min fair rate allocation for ABR control in ATM

In the rate-based flow control for ATM Available Bit Rate service, fairness is an important requirement, i.e. each flow should be allocated a fair share of the available bandwidth in the network. Max–min fairness, which is widely adopted in ATM, is appropriate only when the minimum cell rates (MCRs) of the flows are zero or neglected. Generalised max–min (GMM) fairness extends the principle of the max–min fairness to accommodate MCR. In this paper, we will discuss the formulation of the GMM fair rate allocation, propose a centralised algorithm, analyse its bottleneck structure and develop an efficient distributed explicit rate allocation algorithm to achieve the GMM fairness in an ATM network. The study in this paper addresses certain theoretical and practical issues of the GMM fair rate allocation.

Psychometric analysis of the Brisbane Practice Environment Measure (B-PEM)

Purpose: To undertake rigorous psychometric testing of the newly developed contemporary work environment measure (the Brisbane Practice Environment Measure [B-PEM]) using exploratory factor analysis and confirmatory factor analysis. Methods: Content validity of the 33-item measure was established by a panel of experts. Initial testing involved 195 nursing staff using principal component factor analysis with varimax rotation (orthogonal) and Cronbach's alpha coefficients. Confirmatory factor analysis was conducted using data from a further 983 nursing staff. Results: Principal component factor analysis yielded a four-factor solution with eigenvalues greater than 1 that explained 52.53% of the variance. These factors were then verified using confirmatory factor analysis. Goodness-of-fit indices showed an acceptable fit overall with the full model, explaining 21% to 73% of the variance. Deletion of items took place throughout the evolution of the instrument, resulting in a 26-item, four-factor measure called the Brisbane Practice Environment Measure-Tested. Conclusions: The B-PEM has undergone rigorous psychometric testing, providing evidence of internal consistency and goodness-of-fit indices within acceptable ranges. The measure can be utilised as a subscale or total score reflective of a contemporary nursing work environment. Clinical Relevance: An up-to-date instrument to measure practice environment may be useful for nursing leaders to monitor the workplace and to assist in identifying areas for improvement, facilitating greater job satisfaction and retention.

Validation of the Chinese version of the Problem Areas in Diabetes (PAID-C) scale

OBJECTIVE To examine the psychometric properties of a Chinese version of the Problem Areas In Diabetes (PAID-C) scale. RESEARCH DESIGN AND METHODS The reliability and validity of the PAID-C were evaluated in a convenience sample of 205 outpatients with type 2 diabetes. Confirmatory factor analysis, Bland-Altman analysis, and Spearman's correlations facilitated the psychometric evaluation. RESULTS Confirmatory factor analysis confirmed a one-factor structure of the PAID-C (χ2/df ratio = 1.894, goodness-of-fit index = 0.901, comparative fit index = 0.905, root mean square error of approximation = 0.066). The PAID-C was associated with A1C (rs = 0.15; P < 0.05) and diabetes self-care behaviors in general diet (rs = −0.17; P < 0.05) and exercise (rs = −0.17; P < 0.05). The 4-week test-retest reliability demonstrated satisfactory stability (rs = 0.83; P < 0.01). CONCLUSIONS The PAID-C is a reliable and valid measure to determine diabetes-related emotional distress in Chinese people with type 2 diabetes.

Estimation of the depth focus from wavefront measurements

It is possible to estimate the depth of focus (DOF) of the eye directly from wavefront measurements using various retinal image quality metrics (IQMs). In such methods, DOF is defined as the range of defocus error that degrades the retinal image quality calculated from IQMs to a certain level of the maximum value. Although different retinal image quality metrics are used, currently there have been two arbitrary threshold levels adopted, 50% and 80%. There has been limited study of the relationship between these threshold levels and the actual measured DOF. We measured the subjective DOF in a group of 17 normal subjects, and used through-focus augmented visual Strehl ratio based on optical transfer function (VSOTF) derived from their wavefront aberrations as the IQM. For each subject, a VSOTF threshold level was derived that would match the subjectively measured DOF. Significant correlation was found between the subject’s estimated threshold level and the HOA RMS (Pearson’s r=0.88, p<0.001). The linear correlation can be used to estimate the threshold level for each individual subject, subsequently leading to a method for estimating individual’s DOF from a single measurement of their wavefront aberrations.

Proceedings of the 21st Australian Software Engineering Conference (ASWEC 2010) : 6-9 April 2010, Auckland, New Zealand.

ASWEC is a joint conference of Engineers Australia and the Australian Computer Society reporting through the Engineers Australia/ACS Joint Board on Software Engineering.

The role of cardiopulmonary signals in the dynamics of the eye's wavefront aberrations

Abstract—The role of cardiopulmonary signals in the dynamics of wavefront aberrations in the eye has been examined. Synchronous measurement of the eye’s wavefront aberrations, cardiac function, blood pulse, and respiration signals were taken for a group of young, healthy subjects. Two focusing stimuli, three breathing patterns, as well as natural and cycloplegic eye conditions were examined. A set of tools, including time–frequency coherence and its metrics, has been proposed to acquire a detailed picture of the interactions of the cardiopulmonary system with the eye’s wavefront aberrations. The results showed that the coherence of the blood pulse and its harmonics with the eye’s aberrations was, on average, weak (0.4 ± 0.15), while the coherence of the respiration signal with eye’s aberrations was, on average, moderate (0.53 ± 0.14). It was also revealed that there were significant intervals during which high coherence occurred. On average, the coherence was high (>0.75) during 16% of the recorded time, for the blood pulse, and 34% of the time for the respiration signal. A statistically significant decrease in average coherence was noted for the eye’s aberrations with respiration in the case of fast controlled breathing (0.5 Hz). The coherence between the blood pulse and the defocus was significantly larger for the far target than for the near target condition. After cycloplegia, the coherence of defocus with the blood pulse significantly decreased, while this was not the case for the other aberrations. There was also a noticeable, but not statistically significant, increase in the coherence of the comatic term and respiration in that case. By using nonstationary measures of signal coherence, a more detailed picture of interactions between the cardiopulmonary signals and eye’s wavefront aberrations has emerged.

Analysis of the effect of negation on information retrieval of medical data

Most information retrieval (IR) models treat the presence of a term within a document as an indication that the document is somehow "about" that term, they do not take into account when a term might be explicitly negated. Medical data, by its nature, contains a high frequency of negated terms - e.g. "review of systems showed no chest pain or shortness of breath". This papers presents a study of the effects of negation on information retrieval. We present a number of experiments to determine whether negation has a significant negative affect on IR performance and whether language models that take negation into account might improve performance. We use a collection of real medical records as our test corpus. Our findings are that negation has some affect on system performance, but this will likely be confined to domains such as medical data where negation is prevalent.

Voices of the Unheard

Adversity has the effect of eliciting talents, which, in prosperous circumstances, would have lain dormant. Horace - Roman lyric poet and satirist 65BC – 8 BC This quotation from Horace could well be the chorus to a medley of songs sung by people who face extraordinary adversity and have gained emotional resilience through music making. In this chapter we present three composition ventures that are stories or verses in a new song and whose chorus summarises the nature of the resilience factors present in the narratives. We are aware that words on a page like this can have the effect of filtering out the engaging nature of musical experience and reduce music to a critique or an evaluation of its aesthetic value. This disjuncture between language and the ephemeral, embodied experience is a problem for those who use these creative processes in therapeutic and salutogenic ways (Antonovsky, 1996) for public health. The notion of salutogenic health, put simply, delineates it from therapy in that the processes focus upon wellness rather than therapy. Whilst we include evidence from the fields of community music therapy (Pavlicevic, 2004; Leitschuh et al., 1991), neuroscience (Bittman et al., 2001) and community music (Bartleet et al., 2009) the framework for a salutogenic health outcome in community music is one which seeks to employ music practices and the qualities of music making that provide positive health benefit to communities –to enhance health and well being rather than the “treatment” of disorders. It is essentially a holistic and interdisciplinary study. Therapy and salutogenic health are not mutually exclusive as both depend upon the qualities of music experience to affect change. Collecting, analysing and presenting evidence of change in human behaviour that can be directly attributed to creative music making is a problem of evaluation.

The relationship between Australians and the overseas graves of the First World War

The purpose of this thesis is to outline the relationship that existed in the past and exists in the present, between Australians and the War Graves and Memorials to the Missing. commemorations of Australians who died during the First World War. Their final resting places are scattered all over the world and provide a tangible record of the sacrifice of men and women in the war, and represent the final result by Official Agencies such as the Imperial, and later, Commonwealth War Graves Commission, and its agency representative, the Office of Australian War Graves, of an attempt to appropriately commemorate them. The study follows the path of history from the event of death of an individual in the First World War, through their burial; temporary grave or memorial commemoration; the permanent commemoration; the family and public reaction to the deaths; how the Official Agencies of related Commonwealth Governments dealt with the dead; and finally, how the Australian dead are represented on the battlefields of the world in the 21st century. Australia.s war dead of the First World War are scattered around the globe in more than 40 countries and are represented in war cemeteries and civil cemeteries; and listed on large „Memorials to the Missing., which commemorate the individuals devoid of a known graves or final resting place.

Quantification of the relationship between Fuser Roller Temperature and Laser Printer Emissions

Recently published studies not only demonstrated that laser printers are often significant sources of ultrafine particles, but they also shed light on particle formation mechanisms. While the role of fuser roller temperature as a factor affecting particle formation rate has been postulated, its impact has never been quantified. To address this gap in knowledge, this study measured emissions from 30 laser printers in chamber using a standardized printing sequence, as well as monitoring fuser roller temperature. Based on a simplified mass balance equation, the average emission rates of particle number, PM2.5 and O3 were calculated. The results showed that: almost all printers were found to be high particle number emitters (i.e. > 1.01×1010 particles/min); colour printing generated more PM2.5 than monochrome printing; and all printers generated significant amounts of O3. Particle number emissions varied significantly during printing and followed the cycle of fuser roller temperature variation, which points to temperature being the strongest factor controlling emissions. For two sub-groups of printers using the same technology (heating lamps), systematic positive correlations, in the form of a power law, were found between average particle number emission rate and average roller temperature. Other factors, such as fuser material and structure, are also thought to play a role, since no such correlation was found for the remaining two sub-groups of printers using heating lamps, or for the printers using heating strips. In addition, O3 and total PM2.5 were not found to be statistically correlated with fuser temperature.

Observation of the suppression of water uptake by marine particles

A 4 week intensive measurement campaign was conducted in March–April 2007 at Agnes Water, a remote coastal site on the east coast of Australia. A Volatility-Hygroscopicity-Tandem Differential Mobility Analyser (VH-TDMA) was used to investigate changes in the hygroscopic properties of ambient particles as volatile components were progressively evaporated. Nine out of 18 VH-TDMA volatility scans detected internally mixed multi-component particles in the nucleation and Aitken modes in clean marine air. Evaporation of a volatile, organic-like component in the VH-TDMA caused significant increases in particle hygroscopicity. In 3 scans the increase in hygroscopicity was so large it was explained by an increase in the absolute volume of water uptake by the particle residuals, and not merely an increase in their relative hygroscopicity. This indicates the presence of organic components that were suppressing the hygroscopic growth of mixed particles on the timescale of humidification in the VH-TDMA (6.5 secs). This observation was supported by ZSR calculations for one scan, which showed that the measured growth factors of mixed particles were up to 18% below those predicted assuming independent water uptake of the individual particle components. The observed suppression of water uptake could be due to a reduced rate of hygroscopic growth caused by the presence of organic films or organic-inorganic interactions in solution droplets that had a negative effect on hygroscopicity.

Theoretical analysis of the motion and evaporation of exhaled respiratory droplets of mixed composition

The dynamics of droplets exhaled from the respiratory system during coughing or talking is addressed. A mathematical model is presented accounting for the motion of a droplet in conjunction with its evaporation. Droplet evaporation and motion are accounted for under two scenarios: 1) A well mixed droplet and 2) A droplet with inner composition variation. A multiple shells model was implemented to account for internal mass and heat transfer and for concentration and temperature gradients inside the droplet. The trajectories of the droplets are computed for a range of conditions and the spatial distribution and residence times of such droplets are evaluated.