title: Conflicts and projections

authors: Malik, Robi

subjects: computer science

abstract: This paper studies abstraction methods suitable to verify very large models of discrete-event systems to be nonconflicting. It compares the observer property to methods known from process algebra, namely to conflict equivalence and observation equivalence. The observer property is shown to be the property that corresponds to conflict equivalence in the case where natural projection is used for abstraction. In this case, the observer property turns out to be the least restrictive condition that can be imposed on natural projection to enable compositional reasoning about conflicts. The observer property is also shown to be closely related to observation equivalence. Several examples and propositions are presented to relate different aspects of these methods of abstraction.

text: Conflicts and projections This paper studies abstraction methods suitable to verify very large models of discrete-event systems to be nonconflicting. It compares the observer property to methods known from process algebra, namely to conflict equivalence and observation equivalence. The observer property is shown to be the property that corresponds to conflict equivalence in the case where natural projection is used for abstraction. In this case, the observer property turns out to be the least restrictive condition that can be imposed on natural projection to enable compositional reasoning about conflicts. The observer property is also shown to be closely related to observation equivalence. Several examples and propositions are presented to relate different aspects of these methods of abstraction.

year: 2007

title: Hauraki Gulf sedimentation: Unintended consequences of flood protection

authors: de Lange, Willem P.

abstract: The Universities of Waikato and Bremen have examined sedimentation in the Hauraki Gulf, focussing on the sediment discharges from the Coromandel Peninsula and the Waihou/Ohinemuri river systems, to assess whether anthropic land-use changes over the last millennium have resulted in increased sedimentation rates. Previous studies identified increased sedimentation due to burning of vegetation following Polynesian settlement, and Kauri logging, mining and forest clearance following European settlement. Most studies attribute the highest sedimentation rates to European settlement. This paper considers the results of investigations of depocenters in the central Hauraki Gulf, Southern Firth of Thames, and Coromandel Harbour, as well as the sediment pathway along the Ohinemuri and Waihou Rivers from mining areas of the southern Coromandel Peninsula to the Hauraki Gulf. Contrary to expectations, the central Hauraki Gulf was found to consist of palimpsest fluvial and biogenic marine deposits, with minor Holocene sedimentation lacking a clear anthropic signal. The shallower depocenters contain thicker sequences of Holocene sediments, with high spatial variability. Areas with clear anthropic signals were those proximal to potential sources. Commonly there was a significant time gap between the palynological indications of European settlement and changes in metal concentrations or inferred sedimentation rates, which was inconsistent with historical records suggesting land disturbance was contemporary with settlement. Gold mining in the southern Coromandel Peninsula generated tailings that were deposited into the Ohinemuri River. Initially the Ohinemuri River aggraded and annual floods deposited tailings on the floodplains, predominantly between the Waihou and Ohinemuri Rivers south of Paeroa. Since 1910, the floodplains have progressively been drained and protected by stopbanks constructed from sediment dredged from the beds of rivers and canals, and intertidal flats; with the final major scheme being completed in 1972. Metal concentrations in surficial sediments indicate most tailings have been deposited on floodplains upstream of Paeroa, with little evidence of transport downstream of the Waihou/Ohinemuri confluence. Since the completion of the stopbanks major floods have predominantly discharged sediment into the Firth of Thames, instead of onto the floodplains. The progressive removal of the floodplains as potential depositional sites coincides with the documented expansion of mudflats and mangrove in the southern Firth of Thames. This may also account for the delayed onset of a significant anthropic signal in the Firth of Thames depocenter.

text: Hauraki Gulf sedimentation: Unintended consequences of flood protection The Universities of Waikato and Bremen have examined sedimentation in the Hauraki Gulf, focussing on the sediment discharges from the Coromandel Peninsula and the Waihou/Ohinemuri river systems, to assess whether anthropic land-use changes over the last millennium have resulted in increased sedimentation rates. Previous studies identified increased sedimentation due to burning of vegetation following Polynesian settlement, and Kauri logging, mining and forest clearance following European settlement. Most studies attribute the highest sedimentation rates to European settlement. This paper considers the results of investigations of depocenters in the central Hauraki Gulf, Southern Firth of Thames, and Coromandel Harbour, as well as the sediment pathway along the Ohinemuri and Waihou Rivers from mining areas of the southern Coromandel Peninsula to the Hauraki Gulf. Contrary to expectations, the central Hauraki Gulf was found to consist of palimpsest fluvial and biogenic marine deposits, with minor Holocene sedimentation lacking a clear anthropic signal. The shallower depocenters contain thicker sequences of Holocene sediments, with high spatial variability. Areas with clear anthropic signals were those proximal to potential sources. Commonly there was a significant time gap between the palynological indications of European settlement and changes in metal concentrations or inferred sedimentation rates, which was inconsistent with historical records suggesting land disturbance was contemporary with settlement. Gold mining in the southern Coromandel Peninsula generated tailings that were deposited into the Ohinemuri River. Initially the Ohinemuri River aggraded and annual floods deposited tailings on the floodplains, predominantly between the Waihou and Ohinemuri Rivers south of Paeroa. Since 1910, the floodplains have progressively been drained and protected by stopbanks constructed from sediment dredged from the beds of rivers and canals, and intertidal flats; with the final major scheme being completed in 1972. Metal concentrations in surficial sediments indicate most tailings have been deposited on floodplains upstream of Paeroa, with little evidence of transport downstream of the Waihou/Ohinemuri confluence. Since the completion of the stopbanks major floods have predominantly discharged sediment into the Firth of Thames, instead of onto the floodplains. The progressive removal of the floodplains as potential depositional sites coincides with the documented expansion of mudflats and mangrove in the southern Firth of Thames. This may also account for the delayed onset of a significant anthropic signal in the Firth of Thames depocenter.

year: 2018

title: Māori in the Faculty of Arts and Social Sciences: An analysis of the Faculty of Arts and Social Science data records from 1997-2002

authors: Ashwell, Allanah

subjects: Maori students

abstract: The Ministry of Education has compiled annual reports on the participation of Maori in
tertiary education. The 2002 report presented a comprehensive description of Maori
participation across all tertiary institutions within New Zealand in that year. The figures
show that Maori are markedly under-represented in tertiary institutions, particularly
universities.
The barriers encountered by Maori students can either directly or indirectly impact on
Maori participation, retention and success. The more disturbing outcome is that of
withdrawal or dropping out of higher education, is more likely when a Maori student
experiences and has to confront multiple rather than single barriers.
With this in mind, the aim of this study was to examine and identify trends apparent in
data records of Maori students enrolled in courses offered by the Faculty of Arts and
Social Sciences at the University of Waikato between 1997 and 2002 and to make
recommendations to the Faculty about how negative trends might be addressed. Specific
areas for analysis are detailed in the report.

text: Māori in the Faculty of Arts and Social Sciences: An analysis of the Faculty of Arts and Social Science data records from 1997-2002 The Ministry of Education has compiled annual reports on the participation of Maori in
tertiary education. The 2002 report presented a comprehensive description of Maori
participation across all tertiary institutions within New Zealand in that year. The figures
show that Maori are markedly under-represented in tertiary institutions, particularly
universities.
The barriers encountered by Maori students can either directly or indirectly impact on
Maori participation, retention and success. The more disturbing outcome is that of
withdrawal or dropping out of higher education, is more likely when a Maori student
experiences and has to confront multiple rather than single barriers.
With this in mind, the aim of this study was to examine and identify trends apparent in
data records of Maori students enrolled in courses offered by the Faculty of Arts and
Social Sciences at the University of Waikato between 1997 and 2002 and to make
recommendations to the Faculty about how negative trends might be addressed. Specific
areas for analysis are detailed in the report.

year: 2003-06