title: Design and implementation of an AC voltage regulator based on series power semiconductor array

authors: Vandy, Francis

abstract: This thesis describes the use of an array of power semiconductors (series transistor array) and a buck-boost transformer in the design and implementation of a single phase AC voltage regulator. The power semiconductor array was used to act as variable impedance across the bridge points of a rectifier. The input point of the bridge rectifier was also connected directly to the primary winding of the buck-boost transformer. A closed loop circuit was designed using an RMS/DC converter chip, with complete electrical isolation between the low voltage control circuits and the power circuits. The major advantages of this technique are: fast response to RMS voltage fluctuation; waveform fidelity; light weight; and reduced size compared to that of a servo-driven AC voltage regulator such as the PS10 Smart Power Station, which was used in this project as a benchmark for the AC voltage regulator using the power semiconductor array. The device used for testing the performances of both AC voltage regulators was the NoiseKen VDS-2002 Voltage Dip and Swell Simulator. This simulator was used to perform voltage dip, swell, interruption, and variation tests in a manner fully compliant with IEC 61000 – 4 – 11.

text: Design and implementation of an AC voltage regulator based on series power semiconductor array This thesis describes the use of an array of power semiconductors (series transistor array) and a buck-boost transformer in the design and implementation of a single phase AC voltage regulator. The power semiconductor array was used to act as variable impedance across the bridge points of a rectifier. The input point of the bridge rectifier was also connected directly to the primary winding of the buck-boost transformer. A closed loop circuit was designed using an RMS/DC converter chip, with complete electrical isolation between the low voltage control circuits and the power circuits. The major advantages of this technique are: fast response to RMS voltage fluctuation; waveform fidelity; light weight; and reduced size compared to that of a servo-driven AC voltage regulator such as the PS10 Smart Power Station, which was used in this project as a benchmark for the AC voltage regulator using the power semiconductor array. The device used for testing the performances of both AC voltage regulators was the NoiseKen VDS-2002 Voltage Dip and Swell Simulator. This simulator was used to perform voltage dip, swell, interruption, and variation tests in a manner fully compliant with IEC 61000 – 4 – 11.

year: 2014

title: The Teaching of German as an Additional Language in Tertiary Institutions in Taiwan

authors: Parchwitz, Jörg-Alexander

subjects: Deutsch als Fremdsprache (DaF)

abstract: The research reported here explored the backgrounds, attitudes and professional practices of a sample of teachers of German working in the tertiary education sector in Taiwan using a mixed methods approach involving a questionnaire-based survey, semi-structured interviews and lesson observation and analysis. The overall aim was to determine the extent to which the attitudes and professional practices of the participants reflected awareness of major research-based changes and developments that have taken place in the teaching and learning of additional languages since the heyday of grammar translation.
The questionnaire-based survey involved 35 participants, that is, approximately 32% of the total membership (108) of the Taiwanese Association of German Studies and German Language Teaching at the time of the survey. All were working in the tertiary education sector. Less than one third claimed to have qualifications in the teaching of foreign languages in general or German in particular. Almost two-thirds, including some who had language teaching qualifications, were not satisfied with their teaching or with the proficiency gains of their students. While half believed that their teaching was ‘communicative’, almost three quarters reported that they themselves spoke for half or more of class time. Many were dissatisfied with the conditions of their employment, believing that workloads were too high, in-service training provision was inadequate, and research and publication were valued more highly than teaching.
Ten of the survey participants took part in follow-up semi-structured interviews, with the information and opinion collected reinforcing and/or expanding on some of the questionnaire data. In particular, the interviewees drew attention to problems typically experienced by teachers as a result of lack of effective training, in-service support and program planning and, in addition, the presence of a demanding compliance regime that was perceived to be largely time wasting.
Of 60 classroom sessions recorded in tertiary institutions throughout Taiwan, 55 were reviewed in order to gain an impressionistic overview. Five (5) were transcribed and analyzed in detail. Of the 55 sessions reviewed, 19 were found to involve CLT or aspects of CLT. Of the remaining 36 sessions, half were dominated by grammar translation or aspects of grammar translation and/or audio-lingual methodology or aspects of audio-lingual methodology. The others largely involved straightforward lecturing and/or translation of textbook segments. Of the 5 sessions that were analyzed in detail, 4 were teacher-dominated, with the teacher talking most of the time, generally translating texts or explaining grammar points. Student contributions were largely confined to chorus reading, gap filling and, in some cases, answering teacher initiated questions.
Overall, this research suggests that German is taught in Taiwanese tertiary institutions largely by untrained teachers who are, in common with those who have had some training, struggling to cope in the absence of effective program planning and in the face of very heavy workloads and largely unsupportive and time-consuming compliance regimes. Unless tertiary educational institutions begin to take the needs of these teachers and their students seriously, the dire situation so far as the teaching and learning of German in tertiary institutions in Taiwan is concerned is very unlikely to improve in the future.

text: The Teaching of German as an Additional Language in Tertiary Institutions in Taiwan The research reported here explored the backgrounds, attitudes and professional practices of a sample of teachers of German working in the tertiary education sector in Taiwan using a mixed methods approach involving a questionnaire-based survey, semi-structured interviews and lesson observation and analysis. The overall aim was to determine the extent to which the attitudes and professional practices of the participants reflected awareness of major research-based changes and developments that have taken place in the teaching and learning of additional languages since the heyday of grammar translation.
The questionnaire-based survey involved 35 participants, that is, approximately 32% of the total membership (108) of the Taiwanese Association of German Studies and German Language Teaching at the time of the survey. All were working in the tertiary education sector. Less than one third claimed to have qualifications in the teaching of foreign languages in general or German in particular. Almost two-thirds, including some who had language teaching qualifications, were not satisfied with their teaching or with the proficiency gains of their students. While half believed that their teaching was ‘communicative’, almost three quarters reported that they themselves spoke for half or more of class time. Many were dissatisfied with the conditions of their employment, believing that workloads were too high, in-service training provision was inadequate, and research and publication were valued more highly than teaching.
Ten of the survey participants took part in follow-up semi-structured interviews, with the information and opinion collected reinforcing and/or expanding on some of the questionnaire data. In particular, the interviewees drew attention to problems typically experienced by teachers as a result of lack of effective training, in-service support and program planning and, in addition, the presence of a demanding compliance regime that was perceived to be largely time wasting.
Of 60 classroom sessions recorded in tertiary institutions throughout Taiwan, 55 were reviewed in order to gain an impressionistic overview. Five (5) were transcribed and analyzed in detail. Of the 55 sessions reviewed, 19 were found to involve CLT or aspects of CLT. Of the remaining 36 sessions, half were dominated by grammar translation or aspects of grammar translation and/or audio-lingual methodology or aspects of audio-lingual methodology. The others largely involved straightforward lecturing and/or translation of textbook segments. Of the 5 sessions that were analyzed in detail, 4 were teacher-dominated, with the teacher talking most of the time, generally translating texts or explaining grammar points. Student contributions were largely confined to chorus reading, gap filling and, in some cases, answering teacher initiated questions.
Overall, this research suggests that German is taught in Taiwanese tertiary institutions largely by untrained teachers who are, in common with those who have had some training, struggling to cope in the absence of effective program planning and in the face of very heavy workloads and largely unsupportive and time-consuming compliance regimes. Unless tertiary educational institutions begin to take the needs of these teachers and their students seriously, the dire situation so far as the teaching and learning of German in tertiary institutions in Taiwan is concerned is very unlikely to improve in the future.

year: 2015

title: Imaging and Imagining the Waikato: A Spatial History c.1800-c.1914

authors: Dench, Simon Jeffery

subjects: colonisation

abstract: This thesis reframes the history of the Waikato from the late eighteenth to the early twentieth centuries through a spatial history approach using a visual archive. I argue that Pākehā images of the Waikato were both contemporary records and instruments of colonisation in the region, and that the discursive power of these images is undiminished. In this thesis I focus on spatial occasions represented by maps and photographs in order to reframe the history of colonisation in the Waikato.
First, I move visual sources of historical evidence, specifically maps and photographs, from the periphery to the centre of the frame. An exploration of
the historical context of the selected maps and photographs serves as the narrative framework for the thesis in a strategy that replaces the more usual method of choosing images to illustrate a text that has already been written. This theoretical and methodological framework for what I consider to be a richer and more satisfying use of visual evidence in history is a key feature of this thesis. Second, I employ a colonisation lens to emphasise the negative consequences of colonisation for the indigenous people and landscapes, as well as the diverse and far from unproblematic experiences of the colonists themselves. This thesis positions three phases of Pākehā colonisation: Reconnaissance, Invasion and Occupation. These overtly militaristic labels apply to real military actions as well as to less obvious but longer-lasting and wider-spread discursive strategies of incursion and control.
While this thesis emphasises the negative impacts of colonisation, this is a history from the colonisers’ point of view. The images that form the focus of the thesis were created by Pākehā in the service of Pākehā intentions, actions and identities. But, rather than serving to justify or excuse colonisation as an end that justified the means, I undermine the inevitability inherent in the traditional settlement narrative. I do this by highlighting the ambiguities and contradictions of the colonisers’ intentions and experiences through a close and contextualised reading of the images they made to record and represent themselves. In the process, I refute the legitimacy and validity of Pākehā claims to control Waikato spaces.

text: Imaging and Imagining the Waikato: A Spatial History c.1800-c.1914 This thesis reframes the history of the Waikato from the late eighteenth to the early twentieth centuries through a spatial history approach using a visual archive. I argue that Pākehā images of the Waikato were both contemporary records and instruments of colonisation in the region, and that the discursive power of these images is undiminished. In this thesis I focus on spatial occasions represented by maps and photographs in order to reframe the history of colonisation in the Waikato.
First, I move visual sources of historical evidence, specifically maps and photographs, from the periphery to the centre of the frame. An exploration of
the historical context of the selected maps and photographs serves as the narrative framework for the thesis in a strategy that replaces the more usual method of choosing images to illustrate a text that has already been written. This theoretical and methodological framework for what I consider to be a richer and more satisfying use of visual evidence in history is a key feature of this thesis. Second, I employ a colonisation lens to emphasise the negative consequences of colonisation for the indigenous people and landscapes, as well as the diverse and far from unproblematic experiences of the colonists themselves. This thesis positions three phases of Pākehā colonisation: Reconnaissance, Invasion and Occupation. These overtly militaristic labels apply to real military actions as well as to less obvious but longer-lasting and wider-spread discursive strategies of incursion and control.
While this thesis emphasises the negative impacts of colonisation, this is a history from the colonisers’ point of view. The images that form the focus of the thesis were created by Pākehā in the service of Pākehā intentions, actions and identities. But, rather than serving to justify or excuse colonisation as an end that justified the means, I undermine the inevitability inherent in the traditional settlement narrative. I do this by highlighting the ambiguities and contradictions of the colonisers’ intentions and experiences through a close and contextualised reading of the images they made to record and represent themselves. In the process, I refute the legitimacy and validity of Pākehā claims to control Waikato spaces.

year: 2018