title: Robust stutter bisimulation for abstraction and controller synthesis with disturbance

authors: Krook, Jonas

subjects: controller synthesis

abstract: This paper proposes a method to synthesise controllers for cyber-physical systems subjected to disturbances, such that the controlled system satisfies specifications given as linear temporal logic formulas. To solve this problem, a finite-state abstraction of the original system is first constructed, and then a controller is synthesised for the abstraction. Due to the disturbances and uncertainty in the environment, future states cannot be predicted exactly, and the abstraction must take this into account. For this purpose, the robust stutter bisimulation relation is introduced, which preserves the existence of controllers for any given linear temporal logic formula that excludes the next operator. States are related by the robust stutter bisimulation relation if the same target sets can be guaranteed to be reached or avoided under control of some controller, thus ensuring that disturbances have similar effect on paths that start in related states. It is shown that there exists a controller enforcing a linear temporal logic formula for the original system if and only if a controller exists for the abstracted system. The approach is illustrated by a robot navigation example.

text: Robust stutter bisimulation for abstraction and controller synthesis with disturbance This paper proposes a method to synthesise controllers for cyber-physical systems subjected to disturbances, such that the controlled system satisfies specifications given as linear temporal logic formulas. To solve this problem, a finite-state abstraction of the original system is first constructed, and then a controller is synthesised for the abstraction. Due to the disturbances and uncertainty in the environment, future states cannot be predicted exactly, and the abstraction must take this into account. For this purpose, the robust stutter bisimulation relation is introduced, which preserves the existence of controllers for any given linear temporal logic formula that excludes the next operator. States are related by the robust stutter bisimulation relation if the same target sets can be guaranteed to be reached or avoided under control of some controller, thus ensuring that disturbances have similar effect on paths that start in related states. It is shown that there exists a controller enforcing a linear temporal logic formula for the original system if and only if a controller exists for the abstracted system. The approach is illustrated by a robot navigation example.

year: 2023

title: Empire, environment and religion: God and the natural world in nineteenth-century New Zealand

authors: Beattie, James John

subjects: empire

abstract: This article, using colonial New Zealand as a case-study, and integrating environment, empire and religion into a single analytic framework, contends that Christian and environmental discourses interpenetrated and interacted in irreducibly complex ways during the long nineteenth century. Many of the colony's mostly Protestant settlers interpreted the book of Genesis as giving them responsibility to 'subdue and replenish' the natural world; dominion theology played an important role in legitimising the improvement projects integral to settler capitalism whose consequences have aroused ambivalence from many modern scholars. Yet some, perhaps many, colonists also believed that they had a duty to take care of the land and its creatures even while transforming it. A commitment to large-scale environmental change could and often did co-exist with interest in and respect for nature. When the unexpected and unwanted consequences of environmental transformation became apparent, as they did shortly after the beginning of organised settlement, concerned Protestant community leaders deployed Christian discourse, biblical images and Protestant ethics along with utilitarian and scientific arguments to mobilise environmental concern and a conservationist conscience.

text: Empire, environment and religion: God and the natural world in nineteenth-century New Zealand This article, using colonial New Zealand as a case-study, and integrating environment, empire and religion into a single analytic framework, contends that Christian and environmental discourses interpenetrated and interacted in irreducibly complex ways during the long nineteenth century. Many of the colony's mostly Protestant settlers interpreted the book of Genesis as giving them responsibility to 'subdue and replenish' the natural world; dominion theology played an important role in legitimising the improvement projects integral to settler capitalism whose consequences have aroused ambivalence from many modern scholars. Yet some, perhaps many, colonists also believed that they had a duty to take care of the land and its creatures even while transforming it. A commitment to large-scale environmental change could and often did co-exist with interest in and respect for nature. When the unexpected and unwanted consequences of environmental transformation became apparent, as they did shortly after the beginning of organised settlement, concerned Protestant community leaders deployed Christian discourse, biblical images and Protestant ethics along with utilitarian and scientific arguments to mobilise environmental concern and a conservationist conscience.

year: 2007

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