title: Supercapacitor Assisted Inverter for the purposes of Input Ripple Control

authors: Gaylard, Carl

subjects: Supercapacitor

abstract: This thesis describes the use of a series/parallel supercapacitor to actively control the input ripple of a DC-AC power inverter through the use of a new inverter topology. The topology is made up of two 'sub-inverters' placed in series, with a supercapacitor which is in parallel with one and series with the other. By varying the current draw of each sub-inverter both the current flow into the inverter and the current flow in and out of the supercapacitor can actively be manipulated by adjusting the ratio of the current drawn by each sub-inverter. When the sub-inverter in series with the supercapacitor draws more current than the one in parallel the supercapacitor bank begins charging and more power is drawn by the inverter than is output, conversely when the parallel sub-inverter draws more current than the series one then the supercapacitor bank discharges and the inverter outputs more power than its input. By manipulating the ratio of the current draws the inverter can draw more power than it outputs during low periods of the output cycle and store it, and then release this energy during high periods of the output cycle. This technique overcomes the inefficiencies of using a conventional parallel input capacitor arrangement as the capacitor is charged in series with a load, resulting in only a negligible amount of energy lost in the path resistance.

text: Supercapacitor Assisted Inverter for the purposes of Input Ripple Control This thesis describes the use of a series/parallel supercapacitor to actively control the input ripple of a DC-AC power inverter through the use of a new inverter topology. The topology is made up of two 'sub-inverters' placed in series, with a supercapacitor which is in parallel with one and series with the other. By varying the current draw of each sub-inverter both the current flow into the inverter and the current flow in and out of the supercapacitor can actively be manipulated by adjusting the ratio of the current drawn by each sub-inverter. When the sub-inverter in series with the supercapacitor draws more current than the one in parallel the supercapacitor bank begins charging and more power is drawn by the inverter than is output, conversely when the parallel sub-inverter draws more current than the series one then the supercapacitor bank discharges and the inverter outputs more power than its input. By manipulating the ratio of the current draws the inverter can draw more power than it outputs during low periods of the output cycle and store it, and then release this energy during high periods of the output cycle. This technique overcomes the inefficiencies of using a conventional parallel input capacitor arrangement as the capacitor is charged in series with a load, resulting in only a negligible amount of energy lost in the path resistance.

year: 2016

title: The effect of the "lens of the teacher" on teacher summative assessment literacy and practice

authors: Edwards, Frances

abstract: Teachers’ summative assessment literacy is vital in the current educational environment in New Zealand, given the importance of teachers’ summative judgements in all levels of compulsory education. Through initial teacher education programmes, and inservice professional development and learning, beginner teachers are able to develop assessment knowledge and skills. However, their practice may not reflect what they have learnt.
This paper reports on a qualitative study which aimed to explore the characteristics of summative assessment literacy for secondary beginner teachers, and the contributors to this development. Teachers were interviewed five times over an 18 month period through their initial teacher education programme, and in their first year of employment. The transcripts were analysed by using the model for science teachers’ assessment literacy proposed by Abell and Siegel (2011) as an initial framework. This deductive coding was followed by and merged with subsequent deductive coding as new codes emerged progressively during data analysis.

Summative assessment literacy was found to be an amalgam of knowledges and skills that informed the teachers’ assessment decision making. However, teachers’ assessment decisions were not found to necessarily reflect their knowledge. Teacher commentary indicated that personal and contextual factors acted as amplifiers and/or filters as knowledge became personalised and as the teacher decided how to use it. Personal factors included teacher prior knowledge, experience and beliefs about assessment, teaching, learning, and science; beliefs about ethical matters and, emotional responses to assessment. Contextual factors included beginner teachers’ interactions and experiences with influential others, as well as wider influences such as school policy and practice, and national policy. These factors were found to mediate the translation of teacher professional knowledge to classroom practice, affecting assessment decisions, and sometimes leading to surprising outcomes.
This study provides an alternative view from which to consider teacher development for those working within the partnerships of teacher education and schools. By understanding the effect of teachers’ amplifiers and filters, those working with beginner teachers may be able to make the ‘lens of the teacher’ more explicit with regard to assessment. This in turn may facilitate summative assessment literacy development and assessment decisions that are more likely to be in accord with the principles of good assessment.

text: The effect of the "lens of the teacher" on teacher summative assessment literacy and practice Teachers’ summative assessment literacy is vital in the current educational environment in New Zealand, given the importance of teachers’ summative judgements in all levels of compulsory education. Through initial teacher education programmes, and inservice professional development and learning, beginner teachers are able to develop assessment knowledge and skills. However, their practice may not reflect what they have learnt.
This paper reports on a qualitative study which aimed to explore the characteristics of summative assessment literacy for secondary beginner teachers, and the contributors to this development. Teachers were interviewed five times over an 18 month period through their initial teacher education programme, and in their first year of employment. The transcripts were analysed by using the model for science teachers’ assessment literacy proposed by Abell and Siegel (2011) as an initial framework. This deductive coding was followed by and merged with subsequent deductive coding as new codes emerged progressively during data analysis.

Summative assessment literacy was found to be an amalgam of knowledges and skills that informed the teachers’ assessment decision making. However, teachers’ assessment decisions were not found to necessarily reflect their knowledge. Teacher commentary indicated that personal and contextual factors acted as amplifiers and/or filters as knowledge became personalised and as the teacher decided how to use it. Personal factors included teacher prior knowledge, experience and beliefs about assessment, teaching, learning, and science; beliefs about ethical matters and, emotional responses to assessment. Contextual factors included beginner teachers’ interactions and experiences with influential others, as well as wider influences such as school policy and practice, and national policy. These factors were found to mediate the translation of teacher professional knowledge to classroom practice, affecting assessment decisions, and sometimes leading to surprising outcomes.
This study provides an alternative view from which to consider teacher development for those working within the partnerships of teacher education and schools. By understanding the effect of teachers’ amplifiers and filters, those working with beginner teachers may be able to make the ‘lens of the teacher’ more explicit with regard to assessment. This in turn may facilitate summative assessment literacy development and assessment decisions that are more likely to be in accord with the principles of good assessment.

year: 2017

title: "It's about empowering the whānau": Māori adult students succeeding at university

authors: Williams, Daphne Christina (Tina)

subjects: māori academic success

abstract: A large number of studies have demonstrated that Māori students are not performing well in education. The literature in the general area of Māori education paints a very grim picture that demonstrates a clear preoccupation with failure and underachievement. These studies often overlook the experiences of Māori adult students who return to study long after leaving school and experience considerable success. This paper focuses on the academic success of 16 indigenous students at a New Zealand university. It is based on the findings of a qualitative investigation that explored the experiences of Māori adult students who entered university with very few formal school qualifications and then went on to attain undergraduate degrees. This paper pays particular attention to the role of the whānau in facilitating Māori educational success at university.

text: "It's about empowering the whānau": Māori adult students succeeding at university A large number of studies have demonstrated that Māori students are not performing well in education. The literature in the general area of Māori education paints a very grim picture that demonstrates a clear preoccupation with failure and underachievement. These studies often overlook the experiences of Māori adult students who return to study long after leaving school and experience considerable success. This paper focuses on the academic success of 16 indigenous students at a New Zealand university. It is based on the findings of a qualitative investigation that explored the experiences of Māori adult students who entered university with very few formal school qualifications and then went on to attain undergraduate degrees. This paper pays particular attention to the role of the whānau in facilitating Māori educational success at university.

year: 2011