title: Compositional supervisor synthesis with state merging and transition removal

authors: Mohajerani, Sahar

abstract: This working paper proposes a framework to obtain memory-efficient supervisors for large discrete event systems, which are least restrictive, controllable, and nonblocking. The approach combines compositional synthesis and state-based abstraction with transition removal to mitigate the state-space explosion problem and reduce the memory requirements. Hiding and nondeterminism after abstraction are also supported. To ensure least restrictiveness after transition removal, the synthesised supervisor has the form of cascaded maps representing the safe states. These maps have lower space complexity than previous automata-based supervisors. The algorithm has been implemented in the DES software tool Supremica and applied to compute supervisors for several large industrial models. The results show that supervisor maps can be computed efficiently and in many cases require less memory than automata-based supervisors.

text: Compositional supervisor synthesis with state merging and transition removal This working paper proposes a framework to obtain memory-efficient supervisors for large discrete event systems, which are least restrictive, controllable, and nonblocking. The approach combines compositional synthesis and state-based abstraction with transition removal to mitigate the state-space explosion problem and reduce the memory requirements. Hiding and nondeterminism after abstraction are also supported. To ensure least restrictiveness after transition removal, the synthesised supervisor has the form of cascaded maps representing the safe states. These maps have lower space complexity than previous automata-based supervisors. The algorithm has been implemented in the DES software tool Supremica and applied to compute supervisors for several large industrial models. The results show that supervisor maps can be computed efficiently and in many cases require less memory than automata-based supervisors.

year: 2016

title: Examining the institutional work of sustainability reporting managers and sustainability assurance providers: An institutional work perspective

authors: Farooq, Muhammad Bilal

subjects: Sustainability reporting

abstract: Sustainability reporting and sustainability assurance are new accounting technologies which have been introduced to assist organisations in transitioning to a sustainable growth model. The overarching research objective guiding this study is to understand how sustainability reporting managers (SRMs) prepare sustainability reports and how sustainability assurance providers (SAPs) undertake sustainability assurance. The study draws on Lawrence and Suddaby’s (2006) typology to understand the forms of institutional work SRMs and SAPs undertake as they perform their roles and how these efforts affect the institutionalisation of sustainability reporting and sustainability assurance. Given the interpretive nature of this research the tenants of hermeneutic theory are used to provide the research methodology and research method to guide the investigation. Data comprises of semi-structured interviews with SRMs and SAPs based in Australia and New Zealand. From the overarching research objective, three research questions are addressed. 
The first research question explores the supply-side of the sustainability assurance market. The institutional efforts of accounting sustainability assurance (ASAPs) are directed at institutionalising sustainability assurance as similar to or the same as a traditional financial statements audit. In comparison, the institutional efforts of non-accounting sustainability assurance providers (NASAPs) are directed towards institutionalising sustainability assurance as a vehicle designed to drive sustainability within reporting organisations. 
The second research question explores the institutional work of SRMs as they attempt to institutionalise sustainability reporting within their organisations. SRMs play the role of sustainability reporting champions and sustainability reporting experts. These efforts occur within the backdrop of the new GRI G4 reporting guidelines. As a result, SRMs are changing the normative foundations underlying sustainability reporting from bigger is better to more focused materiality assessment driven reporting. However, while SRMs have been successful in embedding and routinising sustainability reporting these efforts have had a lesser immediate impact in promoting balanced sustainability reporting practices. 
The third research question focuses on the demand-side of the sustainability assurance market.  Given the voluntary nature of sustainability assurance, SAPs institutional efforts are aimed at achieving the dual objectives of enhancing the credibility of sustainability reports and promoting the sustainability assurance as a value added service. However, due to the voluntary nature of sustainability assurance, the efforts of SAPs have had a relatively greater impact in promoting reliable sustainability reporting and less success in promoting balanced sustainability reporting. Finally, the efforts of SAPs in promoting sustainability assurance as a value added activity has also met with difficulties as this study finds that the engagement suffers from diminishing returns. 
The contributions from this study are both practical and academic. At a practical level, the findings will prove beneficial to inexperienced SRMs. The study recommends that given the voluntary nature of the engagement, there is a need for greater regulation designed to strengthen the position of SAPs. At an academic level, the findings build on the limited body of interpretive research examining the phenomena of sustainability reporting and sustainability assurance. Finally, the findings contribute to the literature on institutional work, building on Lawrence and Suddaby’s (2006) typology of forms of institutional work.

text: Examining the institutional work of sustainability reporting managers and sustainability assurance providers: An institutional work perspective Sustainability reporting and sustainability assurance are new accounting technologies which have been introduced to assist organisations in transitioning to a sustainable growth model. The overarching research objective guiding this study is to understand how sustainability reporting managers (SRMs) prepare sustainability reports and how sustainability assurance providers (SAPs) undertake sustainability assurance. The study draws on Lawrence and Suddaby’s (2006) typology to understand the forms of institutional work SRMs and SAPs undertake as they perform their roles and how these efforts affect the institutionalisation of sustainability reporting and sustainability assurance. Given the interpretive nature of this research the tenants of hermeneutic theory are used to provide the research methodology and research method to guide the investigation. Data comprises of semi-structured interviews with SRMs and SAPs based in Australia and New Zealand. From the overarching research objective, three research questions are addressed. 
The first research question explores the supply-side of the sustainability assurance market. The institutional efforts of accounting sustainability assurance (ASAPs) are directed at institutionalising sustainability assurance as similar to or the same as a traditional financial statements audit. In comparison, the institutional efforts of non-accounting sustainability assurance providers (NASAPs) are directed towards institutionalising sustainability assurance as a vehicle designed to drive sustainability within reporting organisations. 
The second research question explores the institutional work of SRMs as they attempt to institutionalise sustainability reporting within their organisations. SRMs play the role of sustainability reporting champions and sustainability reporting experts. These efforts occur within the backdrop of the new GRI G4 reporting guidelines. As a result, SRMs are changing the normative foundations underlying sustainability reporting from bigger is better to more focused materiality assessment driven reporting. However, while SRMs have been successful in embedding and routinising sustainability reporting these efforts have had a lesser immediate impact in promoting balanced sustainability reporting practices. 
The third research question focuses on the demand-side of the sustainability assurance market.  Given the voluntary nature of sustainability assurance, SAPs institutional efforts are aimed at achieving the dual objectives of enhancing the credibility of sustainability reports and promoting the sustainability assurance as a value added service. However, due to the voluntary nature of sustainability assurance, the efforts of SAPs have had a relatively greater impact in promoting reliable sustainability reporting and less success in promoting balanced sustainability reporting. Finally, the efforts of SAPs in promoting sustainability assurance as a value added activity has also met with difficulties as this study finds that the engagement suffers from diminishing returns. 
The contributions from this study are both practical and academic. At a practical level, the findings will prove beneficial to inexperienced SRMs. The study recommends that given the voluntary nature of the engagement, there is a need for greater regulation designed to strengthen the position of SAPs. At an academic level, the findings build on the limited body of interpretive research examining the phenomena of sustainability reporting and sustainability assurance. Finally, the findings contribute to the literature on institutional work, building on Lawrence and Suddaby’s (2006) typology of forms of institutional work.

year: 2016

title: Are they really at risk? Students' stories of success.

authors: Gray, Sheridan

subjects: Student engagement

abstract: In 2011, as the year level dean for year 13, I was surprised and pleased to see a group of students complete their fifth year of secondary schooling, contrary to teacher expectations, and in spite of earlier signs of disengagement and struggle.  Such students are frequently labelled “at risk” in our secondary schools. Truancy, lack of achievement, conduct issues, learning difficulties and health problems are seen as indicators of an at risk student by teachers. 

Statistically in Aotearoa, Māori and Pasifika students and students from low socio-economic families tend to be overrepresented among disengaged or early leavers from secondary schools, and so being from these cultures, and being from a low socio-economic group becomes a “risk” factor.   This can lead to assumptions among teachers about the students’ families, how parents value education, and even about the capacity of these groups to be able to succeed in education.  A range of strategies and programmes have been implemented in an attempt to address these issues, including Te Kotahitanga, Ka Hikitia and the Pasifika Education Plan, Resource Teachers Learning and Behaviour, Restorative Practice, and more recently Positive Behaviour for Learning

While there has been a shift in such approaches from deficit of students to emphasising more positive attitudes in teachers, the perspectives of the students themselves are missing from the discussion about these issues.  This study asks students what factors helped them to stay, and to achieve at least a level one NCEA qualification

The findings show that retention and engagement of “at risk” students requires careful attention to the quality of relationships across the school community: students, teachers and parents. They discredit some commonly held assumptions that “at risk” students and their parents do not value education and that teachers cannot support these students sufficiently. These quality relationships are respectful, responsive and tenacious showing a high level of respect for and interest in the students that goes beyond a teaching and learning relationship.  It also suggests that the discourse of “risk” invites a disrespectful response to retention and engagement of students.

text: Are they really at risk? Students' stories of success. In 2011, as the year level dean for year 13, I was surprised and pleased to see a group of students complete their fifth year of secondary schooling, contrary to teacher expectations, and in spite of earlier signs of disengagement and struggle.  Such students are frequently labelled “at risk” in our secondary schools. Truancy, lack of achievement, conduct issues, learning difficulties and health problems are seen as indicators of an at risk student by teachers. 

Statistically in Aotearoa, Māori and Pasifika students and students from low socio-economic families tend to be overrepresented among disengaged or early leavers from secondary schools, and so being from these cultures, and being from a low socio-economic group becomes a “risk” factor.   This can lead to assumptions among teachers about the students’ families, how parents value education, and even about the capacity of these groups to be able to succeed in education.  A range of strategies and programmes have been implemented in an attempt to address these issues, including Te Kotahitanga, Ka Hikitia and the Pasifika Education Plan, Resource Teachers Learning and Behaviour, Restorative Practice, and more recently Positive Behaviour for Learning

While there has been a shift in such approaches from deficit of students to emphasising more positive attitudes in teachers, the perspectives of the students themselves are missing from the discussion about these issues.  This study asks students what factors helped them to stay, and to achieve at least a level one NCEA qualification

The findings show that retention and engagement of “at risk” students requires careful attention to the quality of relationships across the school community: students, teachers and parents. They discredit some commonly held assumptions that “at risk” students and their parents do not value education and that teachers cannot support these students sufficiently. These quality relationships are respectful, responsive and tenacious showing a high level of respect for and interest in the students that goes beyond a teaching and learning relationship.  It also suggests that the discourse of “risk” invites a disrespectful response to retention and engagement of students.

year: 2012