title: Partial unfolding for compositional nonblocking verification of extended finite-state machines

authors: Mohajerani, Sahar

abstract: This working paper describes a framework for compositional nonblocking veriﬁcation of reactive systems modelled as extended ﬁnite-state machines. The nonblocking property can capture the absence of livelocks and deadlocks in concurrent systems. Compositional veriﬁcation is shown in previous work to be effective to verify this property for large discrete event systems. Here, these results are applied to extended ﬁnite-state machines communicating via shared memory.
The model to be veriﬁed is composed gradually, simplifying components through abstraction at each step, while conﬂict equivalence guarantees that the ﬁnal veriﬁcation result is the same as it would have been for the non-abstracted model. The working paper concludes with an example showing the potential of compositional veriﬁcation to achieve substantial state-space reduction.

text: Partial unfolding for compositional nonblocking verification of extended finite-state machines This working paper describes a framework for compositional nonblocking veriﬁcation of reactive systems modelled as extended ﬁnite-state machines. The nonblocking property can capture the absence of livelocks and deadlocks in concurrent systems. Compositional veriﬁcation is shown in previous work to be effective to verify this property for large discrete event systems. Here, these results are applied to extended ﬁnite-state machines communicating via shared memory.
The model to be veriﬁed is composed gradually, simplifying components through abstraction at each step, while conﬂict equivalence guarantees that the ﬁnal veriﬁcation result is the same as it would have been for the non-abstracted model. The working paper concludes with an example showing the potential of compositional veriﬁcation to achieve substantial state-space reduction.

year: 2013-01-30

title: Secondary School Students' Conceptions of Sustainability

authors: Haines, Elizabeth Anne

subjects: sustainability

abstract: Sustainability is a word that is frequently used and often without the understanding that it warrants.  An understanding of sustainability is vital today as people need to adopt strategies to cope with issues caused by environmental degradation, social inequity and economic disparity.   Education for sustainability has gained momentum after calls by international bodies to provide a vehicle for change to prioritise sustainability and integrate sustainable development at all levels of education.   This thesis investigates what secondary school students understand about the complex concept of sustainability.    It explores students’ conceptions of sustainability, their views about sustainability issues and the relationship between the students’ conceptions and their views about sustainability issues. 
 
This research used a mixed method approach to collect quantitative and qualitative data from questionnaires and follow up focus group interviews.  Open and closed questions were used to investigate students’ conceptions of sustainability and these were compared to conceptions of sustainability that educators and scholars regard as important for citizens to hold for a sustainable future.  Students’ views about sustainability issues were explored using modification of semantic differentials that were directly related to principles of sustainability that had been drawn from the literature.   Data gathered were analysed using a thematic approach and simple statistical tests. 
 
Findings showed that students in this study had some understanding of sustainability.  A minority of students held simple, one dimensional conceptions of sustainability but a significant number of students held conceptions that were more complex and multi-dimensional in nature.  There were no students who held the expert conceptions of sustainability that scholars and educators regard as important, where environmental, economic, cultural, social and political conceptions are interrelated within an inter-generational setting.   Findings also showed that students’ views of sustainability issues, determined from a series of differential statements, indicated that the majority of students agreed or strongly agreed with the sustainable view for most of the environmental, economic, cultural, social, political and inter-generational sustainability issues presented to them.  Comparison of these findings indicated that a student who held a more complex conception of sustainability, and was able to identify a number of conceptions of sustainability, is more likely to make a sustainable choice on an issue if given the opportunity.  These findings are encouraging but, because of the importance of sustainability, they suggest a need to further develop students’ understandings of this complex concept.

text: Secondary School Students' Conceptions of Sustainability Sustainability is a word that is frequently used and often without the understanding that it warrants.  An understanding of sustainability is vital today as people need to adopt strategies to cope with issues caused by environmental degradation, social inequity and economic disparity.   Education for sustainability has gained momentum after calls by international bodies to provide a vehicle for change to prioritise sustainability and integrate sustainable development at all levels of education.   This thesis investigates what secondary school students understand about the complex concept of sustainability.    It explores students’ conceptions of sustainability, their views about sustainability issues and the relationship between the students’ conceptions and their views about sustainability issues. 
 
This research used a mixed method approach to collect quantitative and qualitative data from questionnaires and follow up focus group interviews.  Open and closed questions were used to investigate students’ conceptions of sustainability and these were compared to conceptions of sustainability that educators and scholars regard as important for citizens to hold for a sustainable future.  Students’ views about sustainability issues were explored using modification of semantic differentials that were directly related to principles of sustainability that had been drawn from the literature.   Data gathered were analysed using a thematic approach and simple statistical tests. 
 
Findings showed that students in this study had some understanding of sustainability.  A minority of students held simple, one dimensional conceptions of sustainability but a significant number of students held conceptions that were more complex and multi-dimensional in nature.  There were no students who held the expert conceptions of sustainability that scholars and educators regard as important, where environmental, economic, cultural, social and political conceptions are interrelated within an inter-generational setting.   Findings also showed that students’ views of sustainability issues, determined from a series of differential statements, indicated that the majority of students agreed or strongly agreed with the sustainable view for most of the environmental, economic, cultural, social, political and inter-generational sustainability issues presented to them.  Comparison of these findings indicated that a student who held a more complex conception of sustainability, and was able to identify a number of conceptions of sustainability, is more likely to make a sustainable choice on an issue if given the opportunity.  These findings are encouraging but, because of the importance of sustainability, they suggest a need to further develop students’ understandings of this complex concept.

year: 2014

title: The state of the Rotorua Lakes in 2017

authors: Hamilton, David P.

abstract: I have been asked to give an overview of the Rotorua Te Arawa Lakes and then focus on just four of the lakes. Chris McBride will pick up other lakes.  I would like to acknowledge Warwick Silvester who set up the Lakes Chair, Simon Stuart who is working outside the rohe, on Lake Taupō, but has a great body of knowledge on the food chain in that lake, with potential applications to the Te Arawa lakes. Also to Kohji Muraoka who helped me over the last 24 hours, putting data together which enabled me to synthesise my thoughts on these lakes.

text: The state of the Rotorua Lakes in 2017 I have been asked to give an overview of the Rotorua Te Arawa Lakes and then focus on just four of the lakes. Chris McBride will pick up other lakes.  I would like to acknowledge Warwick Silvester who set up the Lakes Chair, Simon Stuart who is working outside the rohe, on Lake Taupō, but has a great body of knowledge on the food chain in that lake, with potential applications to the Te Arawa lakes. Also to Kohji Muraoka who helped me over the last 24 hours, putting data together which enabled me to synthesise my thoughts on these lakes.

year: 2017