title: Modelling fractal-structured smart microgrids: Exploring signals and protocols

authors: Apperley, Mark

subjects: computer science

abstract: This paper discusses some of the issues surrounding the interconnection of smart microgrids, with a focus on fractal structures, their implementation, management, operation, and potential effectiveness. It builds on a basic smart microgrid model which focuses on the property of localised energy balance, in order to mitigate the dependency on legacy-grid resources to accommodate short-term (hourly) and medium term (daily to monthly) imbalance. This model provides the basis for further development to allow connecting a group of such micro-grids into a network which externally presents identical structure and characteristics, so enabling the fractal-like interconnection of these micro-grids, or groups of microgrids. Such structures simplify the interconnection, management and operation of smart microgrids, and their connection to the legacy grid. They also intrinsically enable the notion of grid-edge trading. These characteristics have the potential not just to further enable and promote the effective utilisation of distributed generation and storage, but also to simplify and rationalise future backbone grid development.

text: Modelling fractal-structured smart microgrids: Exploring signals and protocols This paper discusses some of the issues surrounding the interconnection of smart microgrids, with a focus on fractal structures, their implementation, management, operation, and potential effectiveness. It builds on a basic smart microgrid model which focuses on the property of localised energy balance, in order to mitigate the dependency on legacy-grid resources to accommodate short-term (hourly) and medium term (daily to monthly) imbalance. This model provides the basis for further development to allow connecting a group of such micro-grids into a network which externally presents identical structure and characteristics, so enabling the fractal-like interconnection of these micro-grids, or groups of microgrids. Such structures simplify the interconnection, management and operation of smart microgrids, and their connection to the legacy grid. They also intrinsically enable the notion of grid-edge trading. These characteristics have the potential not just to further enable and promote the effective utilisation of distributed generation and storage, but also to simplify and rationalise future backbone grid development.

year: 2019

title: What's the risk? A comparison of actual and perceived driving risk

authors: Charlton, Samuel G.

subjects: Social Sciences

abstract: It has long been presumed that drivers’ perceptions of risk play an important role in guiding on-road behaviour. The answer to how accurately drivers perceive the momentary risk of a driving situation, however, is unknown. This research compared drivers’ perceptions of the momentary risk for a range of roads to the objective risk associated with those roads. Videos of rural roads, filmed from the drivers’ perspective, were presented to 69 participants seated in a driving simulator while they indicated the momentary levels of risk they were experiencing by moving a risk meter mounted on the steering wheel. Estimates of the objective levels of risk for the roads were calculated using road protection scores from the KiwiRAP database (part of the International Road Assessment Programme). Subsequently, the participants also provided risk estimates for still photos taken from the videos. Another group of 10 participants viewed the videos and photos while their eye movements and fixations were recorded. In a third experiment, 14 participants drove a subset of the roads in a car while providing risk ratings at selected points of interest. Results showed a high degree of consistency across the different methods. Certain road situations were rated as being riskier than the objective risk, and perhaps more importantly, the risk of other situations was significantly under-rated. Horizontal curves and narrow lanes were associated with over-rated risk estimates, while intersections and roadside hazards such as narrow road shoulders, power poles and ditches were significantly under-rated. Analysis of eye movements indicated that drivers did not fixate these features and that the spread of fixations, pupil size and eye blinks were significantly correlated with the risk ratings. An analysis of the road design elements at 77 locations in the video revealed five road characteristics that predicted nearly 80% of the variance in drivers’ risk perceptions; horizontal curvature, lane and shoulder width, gradient, and the presence of median barriers.

text: What's the risk? A comparison of actual and perceived driving risk It has long been presumed that drivers’ perceptions of risk play an important role in guiding on-road behaviour. The answer to how accurately drivers perceive the momentary risk of a driving situation, however, is unknown. This research compared drivers’ perceptions of the momentary risk for a range of roads to the objective risk associated with those roads. Videos of rural roads, filmed from the drivers’ perspective, were presented to 69 participants seated in a driving simulator while they indicated the momentary levels of risk they were experiencing by moving a risk meter mounted on the steering wheel. Estimates of the objective levels of risk for the roads were calculated using road protection scores from the KiwiRAP database (part of the International Road Assessment Programme). Subsequently, the participants also provided risk estimates for still photos taken from the videos. Another group of 10 participants viewed the videos and photos while their eye movements and fixations were recorded. In a third experiment, 14 participants drove a subset of the roads in a car while providing risk ratings at selected points of interest. Results showed a high degree of consistency across the different methods. Certain road situations were rated as being riskier than the objective risk, and perhaps more importantly, the risk of other situations was significantly under-rated. Horizontal curves and narrow lanes were associated with over-rated risk estimates, while intersections and roadside hazards such as narrow road shoulders, power poles and ditches were significantly under-rated. Analysis of eye movements indicated that drivers did not fixate these features and that the spread of fixations, pupil size and eye blinks were significantly correlated with the risk ratings. An analysis of the road design elements at 77 locations in the video revealed five road characteristics that predicted nearly 80% of the variance in drivers’ risk perceptions; horizontal curvature, lane and shoulder width, gradient, and the presence of median barriers.

year: 2014-07-01

title: Youth Development Circles: A Report on a School Trial

authors: Hannah, Belinda Anne

subjects: Youth Development Circles

abstract: This research traces the development and trial of the Youth Development Circle (YDC) process in a low decile secondary school in a rural community in Aotearoa New Zealand. Youth Development Circles are an intervention based on restorative justice principles initially proposed by Braithwaite (2004). They were originally suggested as a strategy for use in an alternative education centre or “activity centre”.  Increasing use of restorative approaches has enabled many schools to make significant progress in reducing suspensions, but there remains a concern for students whose behaviour is at the more serious end of the spectrum - who are at risk of suspension, or exclusion, after multiple stand-downs from school.  The possibilities for the use of YDC were proposed to the school by the researcher, who is a Deputy Principal responsible for behaviour management and pastoral care.  This proposal was supported fully by the school’s staff and Board of Trustees.  The YDC process documented in this study was developed by the researcher, informed by a range of sources including Youth Development Circles, Judge McElrea’s proposed School Community Conference (1996), and Hui Whakatika, developed at the University of Waikato (2003).  Participation in the circles was a condition for the student to remain at the school. The school is a state school, with a roll of approximately 800. The ethnic breakdown of the students is 56% Māori and 39% NZ European with 5% of Pasifika, Asian and other.  

The YDC is a deliberate and careful process which aims to bring increased focus on the individual student and their educational outcomes, through engaging a community of care in supporting them. There were many anticipated benefits of the YDC for the student. Such benefits included an opportunity to establish and maintain healthy relationships of trust (within which negative experiences can be learned from), a re-establishment of trust, improved self-confidence and improved educational outcomes. The circles included members of the student’s whānau/family, a kaumātua/elder who cared about them, and representatives from local Police, Social Welfare, and the school.  The circles were studied over a period of one year.  Circles met regularly throughout this time, at increasing intervals.

A mixed method case study approach was used for this research which includes the collection of both quantitative and qualitative data. The study evaluated the effectiveness of the YDCs by analysing student behaviour, attendance and achievement KAMAR data, minutes of each circle meeting, and interviews with circle participants.


Three student case studies are presented.  The stories have had details altered and pseudonyms used to protect the persons involved. All the students completed the academic year without receiving a further stand down or suspension.  The data showed an improvement in student attendance, achievement and engagement in all three case studies.  Other outcomes include reflections on the process used, strategies for implementation in the school, and factors that either hindered or supported student, family or community involvement in YDCs. 

This exploratory study suggests that the Youth Development Circle could offer a unique possibility for inter-sectorial collaboration in the field of restorative justice.

text: Youth Development Circles: A Report on a School Trial This research traces the development and trial of the Youth Development Circle (YDC) process in a low decile secondary school in a rural community in Aotearoa New Zealand. Youth Development Circles are an intervention based on restorative justice principles initially proposed by Braithwaite (2004). They were originally suggested as a strategy for use in an alternative education centre or “activity centre”.  Increasing use of restorative approaches has enabled many schools to make significant progress in reducing suspensions, but there remains a concern for students whose behaviour is at the more serious end of the spectrum - who are at risk of suspension, or exclusion, after multiple stand-downs from school.  The possibilities for the use of YDC were proposed to the school by the researcher, who is a Deputy Principal responsible for behaviour management and pastoral care.  This proposal was supported fully by the school’s staff and Board of Trustees.  The YDC process documented in this study was developed by the researcher, informed by a range of sources including Youth Development Circles, Judge McElrea’s proposed School Community Conference (1996), and Hui Whakatika, developed at the University of Waikato (2003).  Participation in the circles was a condition for the student to remain at the school. The school is a state school, with a roll of approximately 800. The ethnic breakdown of the students is 56% Māori and 39% NZ European with 5% of Pasifika, Asian and other.  

The YDC is a deliberate and careful process which aims to bring increased focus on the individual student and their educational outcomes, through engaging a community of care in supporting them. There were many anticipated benefits of the YDC for the student. Such benefits included an opportunity to establish and maintain healthy relationships of trust (within which negative experiences can be learned from), a re-establishment of trust, improved self-confidence and improved educational outcomes. The circles included members of the student’s whānau/family, a kaumātua/elder who cared about them, and representatives from local Police, Social Welfare, and the school.  The circles were studied over a period of one year.  Circles met regularly throughout this time, at increasing intervals.

A mixed method case study approach was used for this research which includes the collection of both quantitative and qualitative data. The study evaluated the effectiveness of the YDCs by analysing student behaviour, attendance and achievement KAMAR data, minutes of each circle meeting, and interviews with circle participants.


Three student case studies are presented.  The stories have had details altered and pseudonyms used to protect the persons involved. All the students completed the academic year without receiving a further stand down or suspension.  The data showed an improvement in student attendance, achievement and engagement in all three case studies.  Other outcomes include reflections on the process used, strategies for implementation in the school, and factors that either hindered or supported student, family or community involvement in YDCs. 

This exploratory study suggests that the Youth Development Circle could offer a unique possibility for inter-sectorial collaboration in the field of restorative justice.

year: 2015