Assessing of circuit breaker restrike risks using computer simulation and wavelet analysis

A breaker restrike is an abnormal arcing phenomenon, leading to a possible breaker failure. Eventually, this failure leads to interruption of the transmission and distribution of the electricity supply system until the breaker is replaced. Before 2008, there was little evidence in the literature of monitoring techniques based on restrike measurement and interpretation produced during switching of capacitor banks and shunt reactor banks in power systems. In 2008 a non-intrusive radiometric restrike measurement method and a restrike hardware detection algorithm were developed by M.S. Ramli and B. Kasztenny. However, the limitations of the radiometric measurement method are a band limited frequency response as well as limitations in amplitude determination. Current restrike detection methods and algorithms require the use of wide bandwidth current transformers and high voltage dividers. A restrike switch model using Alternative Transient Program (ATP) and Wavelet Transforms which support diagnostics are proposed. Restrike phenomena become a new diagnostic process using measurements, ATP and Wavelet Transforms for online interrupter monitoring. This research project investigates the restrike switch model Parameter „A. dielectric voltage gradient related to a normal and slowed case of the contact opening velocity and the escalation voltages, which can be used as a diagnostic tool for a vacuum circuit-breaker (CB) at service voltages between 11 kV and 63 kV. During current interruption of an inductive load at current quenching or chopping, a transient voltage is developed across the contact gap. The dielectric strength of the gap should rise to a point to withstand this transient voltage. If it does not, the gap will flash over, resulting in a restrike. A straight line is fitted through the voltage points at flashover of the contact gap. This is the point at which the gap voltage has reached a value that exceeds the dielectric strength of the gap. This research shows that a change in opening contact velocity of the vacuum CB produces a corresponding change in the slope of the gap escalation voltage envelope. To investigate the diagnostic process, an ATP restrike switch model was modified with contact opening velocity computation for restrike waveform signature analyses along with experimental investigations. This also enhanced a mathematical CB model with the empirical dielectric model for SF6 (sulphur hexa-fluoride) CBs at service voltages above 63 kV and a generalised dielectric curve model for 12 kV CBs. A CB restrike can be predicted if there is a similar type of restrike waveform signatures for measured and simulated waveforms. The restrike switch model applications are used for: computer simulations as virtual experiments, including predicting breaker restrikes; estimating the interrupter remaining life of SF6 puffer CBs; checking system stresses; assessing point-on-wave (POW) operations; and for a restrike detection algorithm development using Wavelet Transforms. A simulated high frequency nozzle current magnitude was applied to an Equation (derived from the literature) which can calculate the life extension of the interrupter of a SF6 high voltage CB. The restrike waveform signatures for a medium and high voltage CB identify its possible failure mechanism such as delayed opening, degraded dielectric strength and improper contact travel. The simulated and measured restrike waveform signatures are analysed using Matlab software for automatic detection. Experimental investigation of a 12 kV vacuum CB diagnostic was carried out for the parameter determination and a passive antenna calibration was also successfully developed with applications for field implementation. The degradation features were also evaluated with a predictive interpretation technique from the experiments, and the subsequent simulation indicates that the drop in voltage related to the slow opening velocity mechanism measurement to give a degree of contact degradation. A predictive interpretation technique is a computer modeling for assessing switching device performance, which allows one to vary a single parameter at a time; this is often difficult to do experimentally because of the variable contact opening velocity. The significance of this thesis outcome is that it is a non-intrusive method developed using measurements, ATP and Wavelet Transforms to predict and interpret a breaker restrike risk. The measurements on high voltage circuit-breakers can identify degradation that can interrupt the distribution and transmission of an electricity supply system. It is hoped that the techniques for the monitoring of restrike phenomena developed by this research will form part of a diagnostic process that will be valuable for detecting breaker stresses relating to the interrupter lifetime. Suggestions for future research, including a field implementation proposal to validate the restrike switch model for ATP system studies and the hot dielectric strength curve model for SF6 CBs, are given in Appendix A.

Anthropogenic landscape change promotes asymmetric dispersal and limits regional patch occupancy in a spatially structured bird population

1. Local extinctions in habitat patches and asymmetric dispersal between patches are key processes structuring animal populations in heterogeneous environments. Effective landscape conservation requires an understanding of how habitat loss and fragmentation influence demographic processes within populations and movement between populations. 2. We used patch occupancy surveys and molecular data for a rainforest bird, the logrunner (Orthonyx temminckii), to determine (i) the effects of landscape change and patch structure on local extinction; (ii) the asymmetry of emigration and immigration rates; (iii) the relative influence of local and between-population landscapes on asymmetric emigration and immigration; and (iv) the relative contributions of habitat loss and habitat fragmentation to asymmetric emigration and immigration. 3. Whether or not a patch was occupied by logrunners was primarily determined by the isolation of that patch. After controlling for patch isolation, patch occupancy declined in landscapes experiencing high levels of rainforest loss over the last 100 years. Habitat loss and fragmentation over the last century was more important than the current pattern of patch isolation alone, which suggested that immigration from neighbouring patches was unable to prevent local extinction in highly modified landscapes. 4. We discovered that dispersal between logrunner populations is highly asymmetric. Emigration rates were 39% lower when local landscapes were fragmented, but emigration was not limited by the structure of the between-population landscapes. In contrast, immigration was 37% greater when local landscapes were fragmented and was lower when the between-population landscapes were fragmented. Rainforest fragmentation influenced asymmetric dispersal to a greater extent than did rainforest loss, and a 60% reduction in mean patch area was capable of switching a population from being a net exporter to a net importer of dispersing logrunners. 5. The synergistic effects of landscape change on species occurrence and asymmetric dispersal have important implications for conservation. Conservation measures that maintain large patch sizes in the landscape may promote asymmetric dispersal from intact to fragmented landscapes and allow rainforest bird populations to persist in fragmented and degraded landscapes. These sink populations could form the kernel of source populations given sufficient habitat restoration. However, the success of this rescue effect will depend on the quality of the between-population landscapes.

Leadership practices of Kuwaiti Secondary School Principals for embedding ICT

Globalisation and the emergence of knowledge-based economies have forced many countries to reform their education system. The enhancement of human capital to meet modern day demands of a knowledge economy, and equip the new generation with the capacity to meet the challenges of the 21st Century has become a priority. This change is particularly necessary in economies typical of countries, such as Kuwait, which have been dependent on the exploitation of non-renewable natural resources. Transiting from a resource-based economy to an economy based on knowledge and intellectual skills poses a key challenge for an education system. Significant in the development of this new economy has been the expansion of Information Communication Technology (ICT). In education, in particular, ICT is a tool for transforming the education setting. However, transformation is only successful where there are effective change management strategies and appropriate leadership. At the school level, rapid changes have affected the role that principals take particularly in relation to leading the change process. Therefore, this study investigated the leadership practices of school principals for embedding ICT into schools. The case study assessed two Kuwaiti secondary schools; both schools had well established ICT programs. The mode of data collection used a mixed-methods design, to address the purpose of the study, namely, to examine the leadership practices of school principals when managing the change processes associated with embedding ICT in the context of Kuwait. A theoretical model of principal leadership, developed, from the literature, documented and analysed the practices of the respective school principals. The study used the following five data sources: (a) face to face interviews (with each school principal), and two focus group interviews (with five teachers and five students, from each school); (b) school documents (related to the implementation and embedding of ICT); (c) one survey (of all teachers in each school); (d) an open-ended questionnaire (of participating principals and teachers); and (e) the observation of ICT activities (PD ICT activities and instruction meetings). The study revealed a range of strategies used by the principals and aligned with the theoretical perspective. However, these strategies needed to be refined and selectively used to fit the Kuwait context, both culturally and organisationally. The principals of Schools A and B employed three key strategies to maximise the impact on the teaching staff incorporating ICT into their teaching and learning practices. These strategies were: (a) encouragement for teaching staff to implement ICT in their teaching; (b) support to meet the material and human needs of teaching staff using ICT; and (c) provision of instructions and guidance for teaching staff in how and why such behaviours and practices should be performed. The strategies provided the basic leadership practices required to construct a successful ICT embedded implementation process. Hence, a revised model of leadership that has applicability in the adoption of ICT in Kuwait was developed. The findings provide a better understanding of how a school principal’s leadership practices impact upon the ICT embedding process. Hence, the outcome of this study informs emerging countries, which are also undergoing major change related to ICT, for example, other members of the Cooperation Council for the Arab States of the Gulf. From an educational perspective, this knowledge has the potential to support ICT-based learning environments that will help educational practitioners to effectively integrate ICT into teaching and learning that will facilitate students’ ICT engagement, and prepare them for the ICT development challenges that are associated with the new economy; this is achieved by increasing students’ knowledge and performance. Further, the study offers practical strategies that have been shown to work for school principals leading ICT implementation in Kuwait. These strategies include how to deal with the shortage in schools’ budgets, and the promotion of the ICT vision, as well as developing approaches to build collaborative culture in the schools.

Navigating in a sea of change : second set of working papers of the higher education policy project

This volume represents teh second collection of working papers and articles by participants in the Higher Education Policy Project (HEPP), a project funded by the Australian Research Council and based in the Graduate School of Education at the University of Queensland. The first volume, 'Higher Education in Transition: Working Papers of the Higher Education Policy Project (Bella, McCollow and Knight, 1993), took the broad theme of "higher education in transition" in order to introduce readers the HEPP and give them some idea of the breadth of the research being pursued by the HEPP research team itself and by the cohort of post-graduate students also associated with the project. Since then, higher education has remained in transition. Stubborn and resurgent questions continue: such as what a university ought to be, what forms of research should be supported in a mass system, and how institutional accountability can be demonstrated. In differing ways and using a variety of research perspectives and methodologies, the contributors to this volume explore these and other questions of relevance to higher education today.

Creative industries in China : art, design and media

Creative industries in China provides a fresh account of China’s emerging commercial cultural sector. The author shows how developments in Chinese art, design and media industries are reflected in policy, in market activity, and grassroots participation. Never has the attraction of being a media producer, an artist, or a designer in China been so enticing. National and regional governments offer financial incentives; consumption of cultural goods and services have increased; creative workers from Europe, North America and Asia are moving to Chinese cities; culture is increasingly positioned as a pillar industry. But what does this mean for our understanding of Chinese society? Can culture be industrialised following the low-cost model of China’s manufacturing economy. Is the national government really committed to social liberalisation? This engaging book is a valuable resource for students and scholars interested in social change in China. It draws on leading Chinese scholarship together with insights from global media studies, economic geography and cultural studies.

Researcher attitudes to data sharing : cultural change requires better motivations

While undertaking the ANDS RDA Gold Standard Record Exemplars project, research data sharing was discussed with many QUT researchers. Our experiences provided rich insight into researcher attitudes towards their data and the sharing of such data. Generally, we found traditional altruistic motivations for research data sharing did not inspire researchers, but an explanation of the more achievement-oriented benefits were more compelling.

Risk taking by motorcyclists : rider training and stages of change

Motorcyclists in Australia have been found to be 30 times more likely to be killed per kilometre travelled than car occupants and 40 times more likely to be seriously injured. One approach to preventing motorcycle-related injury is through training and education. While there is traditionally a major focus on developing riding skills during training for motorcyclists, there is also a need for training to promote safe riding to reduce subsequent risk taking. The Transtheoretical Model, commonly known as the ‘Stages of Change’ model, provides a rationale to support incremental behaviour change for risky riding that may be facilitated through motorcycle rider training and education. A sample of 438 learner motorcyclists attended a rider training program in Queensland, Australia, with the stages of change to adopt a safe riding mindset and safe riding practices being measured upon commencement of the course (Time 1) and then again upon completion (Time 2). A small subset of the original sample (n=45) responded at follow up 24 months post training (Time 3). Consistent with the aims of training, results showed a significant shift from the contemplation stage to the subsequent stages of change for participants between Time 1 and Time 2. Progression to the later stages in the model was found for the subset of participants that responded at the Time 3 follow up. Issues of questionnaire design and the utility of the Transtheoretical Model for motorcycle rider training are discussed.

Forecasting success on large projects : developing reliable scales to predict multiple perspectives by multiple stakeholders over multiple time frames

Our aim is to develop a set of leading performance indicators to enable managers of large projects to forecast during project execution how various stakeholders will perceive success months or even years into the operation of the output. Large projects have many stakeholders who have different objectives for the project, its output, and the business objectives they will deliver. The output of a large project may have a lifetime that lasts for years, or even decades, and ultimate impacts that go beyond its immediate operation. How different stakeholders perceive success can change with time, and so the project manager needs leading performance indicators that go beyond the traditional triple constraint to forecast how key stakeholders will perceive success months or even years later. In this article, we develop a model for project success that identifies how project stakeholders might perceive success in the months and years following a project. We identify success or failure factors that will facilitate or mitigate against achievement of those success criteria, and a set of potential leading performance indicators that forecast how stakeholders will perceive success during the life of the project's output. We conducted a scale development study with 152 managers of large projects and identified two project success factor scales and seven stakeholder satisfaction scales that can be used by project managers to predict stakeholder satisfaction on projects and so may be used by the managers of large projects for the basis of project control.

An evolving perspective on physical activity counselling by medical professionals

Background Physical inactivity is a modifiable risk factor for many chronic conditions and a leading cause of premature mortality. An increasing proportion of adults worldwide are not engaging in a level of physical activity sufficient to prevent or alleviate these adverse effects. Medical professionals have been identified as potentially powerful sources of influence for those who do not meet minimum physical activity guidelines. Health professionals are respected and expected sources of advice and they reach a large and relevant proportion of the population. Despite this potential, health professionals are not routinely practicing physical activity promotion. Discussion Medical professionals experience several known barriers to physical activity promotion including lack of time and lack of perceived efficacy in changing physical activity behaviour in patients. Furthermore, evidence for effective physical activity promotion by medical professionals is inconclusive. To address these problems, new approaches to physical activity promotion are being proposed. These include collaborating with community based physical activity behaviour change interventions, preparing patients for effective brief counselling during a consultation with the medical professional, and use of interactive behaviour change technology. Summary It is important that we recognise the latent risk of physical inactivity among patients presenting in clinical settings. Preparation for improving patient physical activity behaviours should commence before the consultation and may include physical activity screening. Medical professionals should also identify suitable community interventions to which they can refer physically inactive patients. Outsourcing the majority of a comprehensive physical activity intervention to community based interventions will reduce the required clinical consultation time for addressing the issue with each patient. Priorities for future research include investigating ways to promote successful referrals and subsequent engagement in comprehensive community support programs to increase physical activity levels of inactive patients. Additionally, future clinical trials of physical activity interventions should be evaluated in the context of a broader framework of outcomes to inform a systematic consideration of broad strengths and weaknesses regarding not only efficacy but cost-effectiveness and likelihood of successful translation of interventions to clinical contexts.

Business planning, idea change, flexibility and performance: the best of both worlds?

The relationships between business planning and performance have divided the entrepreneurship research community for decades (Brinckmann et al, 2010). One side of this debate is the assumption that business plans may lock the firm in a specific direction early on, impede the firm to adapt to the changing market conditions (Dencker et al., 2009) and eventually, cause escalation of commitments by introducing rigidity (Vesper, 1993). Conversely, feedback received from the production and presentation of business plans may also lead the firm to take corrective actions. However, the mechanisms underlying the relationships between changes in business ideas, business plans and the performance of nascent firms are still largely unknown. While too many business idea changes may confuse stakeholders, exhaust the firm’s resources and hinder the undergoing legitimization process, some flexibility during the early stages of the venture may be beneficial to cope with the uncertainties surrounding new venture creation (Knight, 1921; March, 1982; Stinchcombe, 1965; Weick, 1979). Previous research has emphasized adaptability and flexibility as key success factors through effectual logic and interaction with the market (Sarasvathy, 2001; 2007) or improvisation and trial-and-error (Miner et al, 2001). However, those studies did not specifically investigate the role of business planning. Our objective is to reconcile those seemingly opposing views (flexibility versus rigidity) by undertaking a more fine-grained analysis at the relationships between business planning and changes in business ideas on a large longitudinal sample of nascent firms.

Motivators and barriers to incorporating climate change-related health risks in environmental health impact assessment

Climate change presents risks to health that must be addressed by both decision-makers and public health researchers. Within the application of Environmental Health Impact Assessment (EHIA), there have been few attempts to incorporate climate change-related health risks as an input to the framework. This study used a focus group design to examine the perceptions of government, industry and academic specialists about the suitability of assessing the health consequences of climate change within an EHIA framework. Practitioners expressed concern over a number of factors relating to the current EHIA methodology and the inclusion of climate change-related health risks. These concerns related to the broad scope of issues that would need to be considered, problems with identifying appropriate health indicators, the lack of relevant qualitative information that is currently incorporated in assessment and persistent issues surrounding stakeholder participation. It was suggested that improvements are needed in data collection processes, particularly in terms of adequate communication between environmental and health practitioners. Concerns were raised surrounding data privacy and usage, and how these could impact on the assessment process. These findings may provide guidance for government and industry bodies to improve the assessment of climate change-related health risks.

The effect of screen size on mission commander's situation awareness

Situation awareness lost is a common factor leading to human error in the aviation industry. However, few studies have investigated the effect on situation awareness where the control interface is a touch-screen device that supports simultaneous multi-touch input and information output. This research aims to conduct an experiment to evaluate the difference in situation awareness on a large screen device, DiamondTouch (DT107), and a small screen device, iPad, both with multi-touch interactive functions. The Interface Operation and Situation Awareness Testing Simulator (IOSATS), is a simulator to test the three basis interface operations (Search Target, Information Reading, and Change Detection) by implementing a simplified search and rescue scenario. The result of this experiment will provide reliable data for future research for improving operator's situation awareness in the avionic domain.

An integrated approach to professional development in secondary schools

Following the implementation of the National Professional Standards for Teachers, all teachers in Australia will be required to undertake 30 hours per year of professional development (PD) to maintain their registration. However, defining what constitutes effective PD is complex and often contested. This paper looks at a case study in Queensland, Australia, where a high school worked collaboratively with a university lecturer to deliver effective whole-school professional development. The lecturer acted as an external change agent, working closely with the principal and staff to build a relationship of trust and to develop a strategy for the delivery of PD on-site. This case highlights how partnerships between teachers and teacher educators combined with a willing school leader can provide positive opportunities for collaborative, sustainable, professional growth and learning.

The effects of lane-changing on the immediate follower : anticipation, relaxation, and change in driver characteristics

This paper investigates the effects of lane-changing in driver behavior by measuring (i) the induced transient behavior and (ii) the change in driver characteristics, i.e., changes in driver response time and minimum spacing. We find that the transition largely consists of a pre-insertion transition and a relaxation process. These two processes are different but can be reasonably captured with a single model. The findings also suggest that lane-changing induces a regressive effect on driver characteristics: a timid driver (characterized by larger response time and minimum spacing) tends to become less timid and an aggressive driver less aggressive. We offer an extension to Newell’s car-following model to describe this regressive effect and verify it using vehicle trajectory data.

4000 years of phenotypic change in an island bird: heterogeneity of selection over three microevolutionary timescales.

Pronounced phenotypic shifts in island populations are typically attributed to natural selection, but reconstructing heterogeneity in long-term selective regimes remains a challenge. We examined a scenario of divergence proposed for species colonizing a new environment, involving directional selection with a rapid shift to a new optimum and subsequent stabilization. We provide some of the first empirical evidence for this model of evolution using morphological data from three timescales in an island bird, Zosterops lateralis chlorocephalus. In less than four millennia since separation from its mainland counterpart, a substantial increase in body size has occurred and was probably achieved in fewer than 500 generations after colonization. Over four recent decades, morphological traits have fluctuated in size but showed no significant directional trends, suggesting maintenance of a relatively stable phenotype. Finally, estimates of contemporary selection gradients indicated generally weak directional selection. These results provide a rare description of heterogeneity in long-term natural regimes, and caution that observations of current selection may be of limited value in inferring mechanisms of past adaptation due to a lack of constancy even over short time-frames.