title: Nonblocking and safe control of discrete-event systems modeled as extended finite automata

authors: Ouedraogo, L.

subjects: discrete event-systems

abstract: Extended Finite Automata (EFA), i.e., finite automata extended with variables, are a suitable modeling framework for discrete event systems owing to their compactness, resulting from the use of variables. In this paper, we propose a symbolic algorithm that efficiently synthesizes a supervisor for a plant modeled by an EFA and a specification defined by another EFA. The principle of the algorithm is to iteratively strengthen the guards of the plant EFA so that forbidden or blocking states become unreachable in the controlled plant. As a consequence of the algorithm, the controlled behavior is modeled by an EFA having the same structure as the plant EFA, having stronger guards and is shown to be maximally permissive. We illustrate our algorithm via a simple manufacturing example.

text: Nonblocking and safe control of discrete-event systems modeled as extended finite automata Extended Finite Automata (EFA), i.e., finite automata extended with variables, are a suitable modeling framework for discrete event systems owing to their compactness, resulting from the use of variables. In this paper, we propose a symbolic algorithm that efficiently synthesizes a supervisor for a plant modeled by an EFA and a specification defined by another EFA. The principle of the algorithm is to iteratively strengthen the guards of the plant EFA so that forbidden or blocking states become unreachable in the controlled plant. As a consequence of the algorithm, the controlled behavior is modeled by an EFA having the same structure as the plant EFA, having stronger guards and is shown to be maximally permissive. We illustrate our algorithm via a simple manufacturing example.

year: 2011

title: After the Civilian: Compassion in a changing politico-military context

authors: McKeogh, Colm

abstract: This paper looks at political, military and technological challenges to the rule against targeting civilians in war. Neither the concept nor the reality of the civilian offer the clarity once assumed. The paper argues that the category of the civilian is now collapsing and that new expressions of practical compassion in armed conflict must rise to take its place. Religions have a role to play in promoting the restraint of violence although that role will be more one of motivation than overtly religious argument.

text: After the Civilian: Compassion in a changing politico-military context This paper looks at political, military and technological challenges to the rule against targeting civilians in war. Neither the concept nor the reality of the civilian offer the clarity once assumed. The paper argues that the category of the civilian is now collapsing and that new expressions of practical compassion in armed conflict must rise to take its place. Religions have a role to play in promoting the restraint of violence although that role will be more one of motivation than overtly religious argument.

year: 2017

title: An outsider's guide to public oral history in New Zealand

authors: Mahuika, Nepia

subjects: Oral history

abstract: At the beginning of this century, public history in New Zealand was considered a ‘new term’ in historical practice, described as crucial in both ‘the emergence of professional history writing’ and the assertion of ‘cultural nationalism.’¹ In the past decade, scholars here have highlighted its breadth and significance in ‘the employment of historians and the historical method outside academia; in government, private companies, the media, historical societies and museums, as well as those working in private practice.’² Oral history has also become a significant part of public history’s nation-making, key in the collecting of exceptional and ‘ordinary’ public voices.³ For Māori, current definitions of oral and public history are problematic because, as this essay suggests, both are constructed within Pākehā-centric perspectives of history, tradition, orality and what counts as ‘public.’ Public history has been called a ‘slippery process’, often shaped in a contrast between ‘people’s history’ and a ‘search for social cohesion’.4 This search for ‘cohesion’ is a familiar colonial refrain that fuels a healthy native scepticism of public history as yet another settler-centric invention that keeps us on the outside. This essay considers the ways in which public oral history in New Zealand is articulated, noting how this is done within narrow definitions and binaries that displace, ignore, or distort, indigenous perspectives. It suggests a rethinking of oral history as a movement beyond current binaries in the field, and advocates a widening of the meaning of oral sources, methods and politics, in order to include indigenous definitions as legitimately oral and public. This analysis is decolonial, not because it seeks an eradication of nationalism, but because it seeks to disrupt colonial-centric meanings of oral and public history by recentering Māori perspectives as legitimate to the New Zealand public oral history vernacular.

text: An outsider's guide to public oral history in New Zealand At the beginning of this century, public history in New Zealand was considered a ‘new term’ in historical practice, described as crucial in both ‘the emergence of professional history writing’ and the assertion of ‘cultural nationalism.’¹ In the past decade, scholars here have highlighted its breadth and significance in ‘the employment of historians and the historical method outside academia; in government, private companies, the media, historical societies and museums, as well as those working in private practice.’² Oral history has also become a significant part of public history’s nation-making, key in the collecting of exceptional and ‘ordinary’ public voices.³ For Māori, current definitions of oral and public history are problematic because, as this essay suggests, both are constructed within Pākehā-centric perspectives of history, tradition, orality and what counts as ‘public.’ Public history has been called a ‘slippery process’, often shaped in a contrast between ‘people’s history’ and a ‘search for social cohesion’.4 This search for ‘cohesion’ is a familiar colonial refrain that fuels a healthy native scepticism of public history as yet another settler-centric invention that keeps us on the outside. This essay considers the ways in which public oral history in New Zealand is articulated, noting how this is done within narrow definitions and binaries that displace, ignore, or distort, indigenous perspectives. It suggests a rethinking of oral history as a movement beyond current binaries in the field, and advocates a widening of the meaning of oral sources, methods and politics, in order to include indigenous definitions as legitimately oral and public. This analysis is decolonial, not because it seeks an eradication of nationalism, but because it seeks to disrupt colonial-centric meanings of oral and public history by recentering Māori perspectives as legitimate to the New Zealand public oral history vernacular.

year: 2017