title: Implementation considerations in supervisory control

authors: Malik, Robi

subjects: computer science

abstract: With supervisory control theory it is possible to describe controllers which influence the behaviour of a system by disabling controllable events. But sometimes it is desirable to have a controller which not only disables controllable events but also chooses one among the enabled ones. This event can be interpreted as a command given to the plant. This idea is formalized in the concept of an implementation, which is a special supervisor, enabling at most one controllable event at a time. In this paper, some useful properties are introduced, which ensure, when met, that each implementation of a given DES is nonblocking. The approach is applied to a simple chemical batch process example.

text: Implementation considerations in supervisory control With supervisory control theory it is possible to describe controllers which influence the behaviour of a system by disabling controllable events. But sometimes it is desirable to have a controller which not only disables controllable events but also chooses one among the enabled ones. This event can be interpreted as a command given to the plant. This idea is formalized in the concept of an implementation, which is a special supervisor, enabling at most one controllable event at a time. In this paper, some useful properties are introduced, which ensure, when met, that each implementation of a given DES is nonblocking. The approach is applied to a simple chemical batch process example.

year: 2001-06

title: The effect of some environmental factors on rapid mass movement in the Hunua Ranges, New Zealand

authors: Pain, C.F.

abstract: This paper describes some of the relationships between rapid mass movement and environmental factors in the Hunua Ranges.
Extreme climatic events appear to be important in triggering mass movement, while vegetation has a marked effect on mass movement processes and resulting landforms. The main effects of lithology and soils are connected with their influence on site conditions of mass movement. Drainage basin morphometry is affected by the addition of channels produced by mass movement.

text: The effect of some environmental factors on rapid mass movement in the Hunua Ranges, New Zealand This paper describes some of the relationships between rapid mass movement and environmental factors in the Hunua Ranges.
Extreme climatic events appear to be important in triggering mass movement, while vegetation has a marked effect on mass movement processes and resulting landforms. The main effects of lithology and soils are connected with their influence on site conditions of mass movement. Drainage basin morphometry is affected by the addition of channels produced by mass movement.

year: 1969

title: Artefacts, biology and bias in museum collection research

authors: Wehi, Priscilla M.

subjects: experimenta design

abstract: Museum collections are increasingly subjected to scientific scrutiny, including molecular, isotopic and trace-element analyses. Recent advances have extended analyses from natural history specimens to historical artefacts. We highlight three areas of concern that can influence interpretation of data derived from museum collections: sampling issues associated with museum collection use, methods of analysis, and the value of cross-referencing data with historical documents and data sets. We use a case study that focuses on kiwi (Apteryx spp.) feather samples from valuable 19th century Māori cloaks in New Zealand to show how sampling and analysis challenges need to be minimized by careful design. We argue that aligning historical records with scientific data generated from museum collections significantly improves data interpretation.

text: Artefacts, biology and bias in museum collection research Museum collections are increasingly subjected to scientific scrutiny, including molecular, isotopic and trace-element analyses. Recent advances have extended analyses from natural history specimens to historical artefacts. We highlight three areas of concern that can influence interpretation of data derived from museum collections: sampling issues associated with museum collection use, methods of analysis, and the value of cross-referencing data with historical documents and data sets. We use a case study that focuses on kiwi (Apteryx spp.) feather samples from valuable 19th century Māori cloaks in New Zealand to show how sampling and analysis challenges need to be minimized by careful design. We argue that aligning historical records with scientific data generated from museum collections significantly improves data interpretation.

year: 2012-07