Power converters design and analysis for high power piezoelectric ultrasonic transducers

High power piezoelectric ultrasonic transducers have been widely exploited in a variety of applications. The critical behaviour of a piezoelectric device is encapsulated in its resonant frequencies because of its maximum transmission performance at these frequencies. Therefore power electronic converters should be tuned at those resonant frequencies to transfer electrical power to mechanical power efficiently. However, structural and environmental changes cause variations in the device resonant frequencies which can degrade the system performance. Hence, estimating the device resonant frequencies within the incorporated setup can significantly improve the system performance. This paper proposes an efficient resonant frequency estimation approach to maintain the performance of high power ultrasonic applications using the employed power converter. Experimental validations indicate the effectiveness of the proposed method.

Rethinking the literacy capabilities of pre-service primary teachers in testing times

As a group of committed literacy teacher educators from five universities across three Australian states, the authors bring professional critique to the problematic issue of what counts in current and possible future measures of pre-service teachers��� literacy capacity. In times when normalising models of literacy assessment ignore innovative developments in technologies, we provide an example of what is happening at the ���chalk-face��� of literacy teacher education. This paper describes a study that demonstrates how responsible alignment of teacher accreditation requirements with a scholarly impetus to incorporate digital literacies to prepare pre-service teachers will help address changing educational needs and practices (AITSL 2012; Gillen & Barton 2010; Hattie 2003; Johnson, Smith, Willis, Levine & Haywood 2011; Klein 2006; Masny & Cole 2012; OECD 2011).

Understanding VET teachers' dilemmas in providing quality education to international students in Brisbane

In the past fifteen years, increasing attention has been given to the role of Vocational Education and Training (VET) in attracting large numbers of international students and its contribution to the economic development of Australia. This trend has given rise to many challenges in vocational education, especially with regard to providing quality education that ensures international students' stay in Australia is a satisfactory experience. Teaching and learning is continuously scrutinized, teaching quality and student assessment are subject to regular audit (Takerei, 2010). VET teachers are key stakeholders in international education and share responsibility for ensuring international students gain quality learning experiences and positive outcomes, however, their experiences are generally not well understood. Therefore, this thesis, investigates particular challenges and associated dilemmas that VET teachers experience when teaching international students. The research participants were 15 teachers from several public and private VET institutions in Brisbane, Australia. The method involved responsive interviewing and inductive data analysis to identify and categorize teachers' challenges and dilemmas. The research reveals qualitatively different ways in which the 15 VET educators experienced challenges and associated dilemmas in their culturally diverse teaching context. The research shows that VET teachers experience numerous challenges and various inter-related professional, educational and personal dilemmas. These dilemmas result from ethical tensions teachers experience in their interactions with international students, teaching colleagues and their employment institutions. The dilemmas are often influenced by current economic and political conditions of international education. The dilemmas raised in the study by 15 VET teachers might be familiar to other teachers in VET and universities but to date they have received limited attention by researchers. This study's findings indicate significant implications for VET teachers, students, VET institutions and the government at a time of rapid economic, political, cultural and educational change. The findings are of potential interest to VET policy makers, managers and teachers. By giving voice to VET teachers, who are key stakeholders in the sustainability and future growth of VET, they contribute evidence for ongoing review and development of quality learning and teaching in the culturally diverse VET sector.

Identifying leadership practices for mentoring preservice teachers

There are many forms of leadership and concepts of school leadership have evolved significantly over the last few decades. Mentoring is a form of leadership, where the classroom teacher (mentor) leads and guides the preservice teacher towards advancing teaching practices. What do school executives identify as their leadership practices and what leadership practices have inspired them? This study uses a five-part Likert scale survey with extended written responses that were coded into themes. These participants indicated they had leadership potential, which they associated with being organised, passionate and knowledgeable about education, interpersonally-skilled to build relationships, and visionary with action plans for improving education. These practices were also identified by participants as inspiring practices from leaders they knew. Generally, these participants perceived themselves as transformational leaders. Transformational practices associated with individualized consideration, intellectual stimulation, inspirational motivation, and idealized influences were agreed upon by 80% or more of the participants. Mentors need to understand inspiring leadership practices and identify their own leadership practices that may lead towards reflection on practice and, hence, a way to make educationally-sound changes in leadership behaviour.

Acknowledging, moving toward and transcending psychophysiological angst during a paradox of conflicting desires

In this paper I integrate the work of a number of philosophers to clarify some psychological issues that can arise in human existence when a conflict of intrapersonal or interpersonal desires arises. This paper utilises the work of Deleuze, Freud, Jung, Heidegger, Hegel and Nietzsche to provide a conceptual framework as to how mental disturbances can arise if unconscious desires cannot be satisfied due to the experience of a resistance from a conflicting or opposing desire. This paper argues that the phenomenal experience of a conflict of desires can be unconcealed in moments of un-readiness-to-hand and from the awareness of the psychophysiological experience of stress or angst. The work that is presented, results in the conclusion that it is fundamentally necessary to embrace Nietzsche���s idea of the ���will to power��� to overcome these difficulties and to achieve personal individuation and authentic wellbeing. This advice is in contrast to an inauthentic choice of depending on the use of Freudian defence mechanisms to conceal a conflict of desires from consciousness. A detailed theoretical example of the process involved in the resolution of a conflict of desires through self-transcendence is specifically informed by the ideas of Nietzsche and Jung.

Experience, recursive awareness and understanding in autism spectrum disorders : insights of parents and teachers in Singapore

Provision of an individually responsive education requires a comprehensive understanding of the inner worlds of learners, such as their feelings and thoughts. However, this is difficult to achieve when learners, such as those with Autism Spectrum Disorders (ASD) and cognitive difficulties, have problems with communication. To address this issue, the current exploratory descriptive study sought the views of 133 Singaporean parents and teachers of school-age learners with ASD and cognitive difficulties regarding the inner experience of their children and students. The findings highlight the variety of abilities and difficulties found in how these learners experience their own mental states and understand those of others. These abilities and difficulties are characterized according to type of mental state and analysed in line with three qualia, those of experience, recursive awareness and understanding. The findings indicate that learners show a greater awareness of their own mental states compared to their ability to understand these same mental states in others. Educational implications are discussed.

How transit route passenger load and distance can together influence quality of service

This paper investigates quality of service and resource productivity implications of transit route passenger loading and travel distance. Weekday Automatic Fare Collection data for a premium radial bus route in Brisbane, Australia, is used to investigate correlation between load factor and distance factor. Relationships between boardings and transit work indicate that distance factor generally increases with load factor. Time series analysis is then presented by examining each direction on an hour by hour basis. Inbound correlation is medium to strong across the entire span of service and strong for daytime services up to 19:30, while outbound correlation is strong across the entire span. Passengers tend to be making longer distance, peak direction commuter trips under the least comfortable conditions under stretched peak schedules than off-peak. Therefore productivity gains may be possible by adjusting fleet utilization during off-peak times. Weekday profiles by direction are established for a composite load-distance factor. A threshold corresponding to standing passengers on the Maximum Load Segment reveals that on-board loading and travel distance combined are more severe during the morning inbound peak than evening outbound peak, although the sharpness of the former suggests that encouraging shoulder peak travel during the morning would be more effective than evening peak. Further research suggested includes: consideration of travel duration factor, relating noise within hour to Peak Hour Factor, profiling load-distance factor across a range of case studies, and relating load-distance factor threshold to line length.

Recovering from the earthquake : early childhood teachers and children collaboratively telling stories about their experiences

Purpose ��� Traumatic events can cause post-traumatic stress disorder due to the severity of the often unexpected events. The purpose of this paper is to reveal how conversations around lived experiences of traumatic events, such as the Christchurch earthquake in February 2011, can work as a strategy for people to come to terms with their experiences collaboratively. By encouraging young children to recall and tell of their earthquake stories with their early childhood teachers they can begin to respond, renew, and recover (Brown, 2012), and prevent or minimise more stress being developed. Design/methodology/approach ��� The study involved collecting data of the participating children taking turns to wear a wireless microphone where their interactions with each other and with teachers were video recorded over one week in November 2011. A total of eight hours and 21 minutes of footage was collected; four minutes and 19 seconds of that footage are presented and analysed in this paper. The footage was watched repeatedly and transcribed using conversation analysis methods (Sacks, 1995). Findings ��� Through analysing the detailed turn-taking utterances between teachers and children, the orderliness of the co-production of remembering is revealed to demonstrate that each member orients to being in agreement about what actually happened. These episodes of story telling between the teachers and children demonstrate how the teachers encourage the children to tell about their experiences through actively engaging in conversations with them about the earthquake. Originality/value ��� The conversation analysis approach used in this research was found to be useful in investigating aspects of disasters that the participants themselves remember as important and real. This approach offers a unique insight into understanding how the earthquake event was experienced and reflected on by young children and their teachers, and so can inform future policy and provision in post-disaster situations.

"I can't believe I just said that": Using guided reflections with non-Indigenous pre-service teachers in Australia

This paper explores the use of guided narrative reflection as a strategy used with high-achieving non-Indigenous pre-service teachers in Australia on teaching practicum. We suggest that reflections (and subsequent dialogue) can provide opportunities for non-Indigenous preservice teachers to re-think their beliefs and actions in ways that may intervene in the teaching that often causes educational disadvantage for Aboriginal and Torres Strait Islander students.

Investigating relationships between relationship quality, customer loyalty and cooperation : an empirical study of convenience stores' franchise chain systems

Franchising has become a way to minimise the risks of small business management. There has been little research into the factors that promote franchise relationship success. This study attempts to empirically examine the important elements (relationship quality, customer loyalty and cooperation), which might promote a successful long-term franchising relationship between franchisors and franchisees within the context of convenience stores in Taiwan. A model of these relationships was developed and tested. A total of 500 surveys were mailed to a random sample of convenience stores��� franchisee owners among the four main franchisors in Taiwan. The results show that relationship quality positively influences the cooperation between franchisors and franchisees and is positively correlated with franchisee loyalty. Additionally, the cooperative behaviour between franchisees and franchisors is significantly associated with franchisees��� loyalty.

Control, operation and power sharing among parallel converter-interfaced DERs in a microgrid in the presence of unbalanced and harmonic loads

This paper demonstrates power management and control of DERs in an autonomous MG. The paper focuses on the control and performance of converter-interfaced DERs in voltage controlled mode. Several case studies are considered for a MG based on the different types of loads supplied by the MG (i.e. balanced three-phase, unbalanced, single-phase and harmonic loads). DERs are controlled by adjusting the voltage magnitude and angle in their converter output through droop control, in a decentralized concept. Based on this control method, DERs can successfully share the total demand of the MG in the presence of any type of loads. This includes proper total power sharing, unbalanced power sharing as well as harmonic power sharing, depending on the load types. The efficacy of the proposed power control, sharing and management among DERs in a microgrid is validated through extensive simulation studies using PSCAD/EMTDC.

Voltage regulation, power balancing and battery storage discharge control by smart demand side management and multi-objective decision making

A novel intelligent online demand side management system is proposed for peak load management. The method also regulates the network voltage, balances the power in three phases and coordinates the battery storage discharge within the network. This method uses low cost controllers with low bandwidth two-way communication installed in costumers' premises and at distribution transformers to manage the peak load while maximizing customer satisfaction. A multi-objective decision making process is proposed to select the load(s) to be delayed or controlled. The efficacy of the proposed control system is verified through an event-based developed simulation in Matlab.

Tell me what you see : pre-service teachers' recognition of exemplary digital pedagogy

How do you identify "good" teaching practice in the complexity of a real classroom? How do you know that beginning teachers can recognise effective digital pedagogy when they see it? How can teacher educators see through their students��� eyes? The study in this paper has arisen from our interest in what pre-service teachers ���see��� when observing effective classroom practice and how this might reveal their own technological, pedagogical and content knowledge. We asked 104 pre-service teachers from Early Years, Primary and Secondary cohorts to watch and comment upon selected exemplary videos of teachers using ICT (information and communication technologies) in Science. The pre-service teachers recorded their observations using a simple PMI (plus, minus, interesting) matrix which were then coded using the SOLO Taxonomy to look for evidence of their familiarity with and judgements of digital pedagogies. From this, we determined that the majority of preservice teachers we surveyed were using a descriptive rather than a reflective strategy, that is, not extending beyond what was demonstrated in the teaching exemplar or differentiating between action and purpose. We also determined that this method warrants wider trialling as a means of evaluating students��� understandings of the complexity of the digital classroom.

Recruiting career-change professionals as teachers: the challenge of socialization into teaching

In many countries there is a shortage of quality teachers in areas of science, technology, engineering and mathematics (STEM). One solution has been to encourage mid-career professionals in the area of STEM to become school teachers. The transition of mid-career professionals to science and mathematics teaching in schools is thus becoming a common phenomenon. The assumption exists that their experiences and enthusiasm for their subject matter will inspire more students to achieve greater outcomes in school and to pursue careers in the sciences. Although the experiences of beginning teachers have been extensively studied for over half a century, there has been little research on career-change teachers and the particular challenges that they face in becoming school teachers. These career-changers have constructed professional identities and are accustomed to working within a culture of collaboration and inquiry. In contrast school cultures are quite different and often teaching is a lonely solitary affair with little opportunity for collegial relationships aimed at knowledge building in the context of teaching. This research was a longitudinal study that followed 17 teachers from the commencement of teaching. Most of these teachers left professional careers to become teachers. Seven remained in teaching after three years.

Linking ecological condition and the soundscape in fragmented Australian forests

Natural landscapes are increasingly subjected to anthropogenic pressure and fragmentation resulting in reduced ecological condition. In this study we examined the relationship between ecological condition and the soundscape in fragmented forest remnants of south-east Queensland, Australia. The region is noted for its high biodiversity value and increased pressure associated with habitat fragmentation and urbanisation. Ten sites defined by a distinct open eucalypt forest community dominated by spotted gum (Corymbia citriodora ssp. variegata) were stratified based on patch size and patch connectivity. Each site underwent a series of detailed vegetation condition and landscape assessments, together with bird surveys and acoustic analysis using relative soundscape power. Univariate and multivariate analyses indicated that the measurement of relative soundscape power reflects ecological condition and bird species richness, and is dependent on the extent of landscape fragmentation. We conclude that acoustic monitoring technologies provide a cost effective tool for measuring ecological condition, especially in conjunction with established field observations and recordings.