title: Modular nonblocking verification using conflict equivalence

authors: Malik, Robi

subjects: computer science

abstract: This paper proposes a modular approach to verifying
whether a large discrete event system is nonconflicting.
The new approach avoids computing the synchronous
product of a large set of finite-state machines. Instead, the
synchronous product is computed gradually, and intermediate
results are simplified using conflict-preserving abstractions
based on process-algebraic results about fair testing. Heuristics
are used to choose between different possible abstractions.
Experimental results show that the method is applicable to
finite-state machine models of industrial scale and brings
considerable improvements in performance over other methods.

text: Modular nonblocking verification using conflict equivalence This paper proposes a modular approach to verifying
whether a large discrete event system is nonconflicting.
The new approach avoids computing the synchronous
product of a large set of finite-state machines. Instead, the
synchronous product is computed gradually, and intermediate
results are simplified using conflict-preserving abstractions
based on process-algebraic results about fair testing. Heuristics
are used to choose between different possible abstractions.
Experimental results show that the method is applicable to
finite-state machine models of industrial scale and brings
considerable improvements in performance over other methods.

year: 2006-07

title: The performance of thermally sprayed titanium based composite coatings in molten aluminium

authors: Salman, Asma Siddiq

subjects: mechanical milling

abstract: The service life of die and tool steels in contact with molten aluminium is important in the aluminium processing industry. This article describes an investigation of the efficiency of thermally sprayed Ti(Al,O)/Al₂O₃ and TiAl(O)/Al₂O₃ composite coatings in resisting aluminium soldering on H13 tool steel. The powder feedstocks for making the composite coatings were produced by high energy mechanical milling of a mixture of Al and TiO₂ powders using different molar ratios followed by a thermal reaction process. The feedstocks were then thermally sprayed using a high velocity oxygen fuel (HVOF) technique onto an H13 steel substrate to produce composite coatings. The performance of the coatings was assessed in terms of Al soldering and liquid metal corrosion resistance after immersing in molten aluminium at a temperature of 700 ± 10 °C. The results of this study showed that composite coatings have a potential to act as a physical barrier to prevent aluminium attack on H13 tool steel. The nature of Al attack on H13 tool steel changed from generalised to more localised attack with the thermally sprayed coating. A Ti(Al,O)/Al₂O₃ composite coating was not attacked by molten aluminium, however localised attack on a H13 tool steel substrate was found to be caused by molten metal penetration through defects in the coating. Composite coating TiAl(O)/Al₂O₃ was attacked by molten aluminium resulting in dissolution of the coating. Composite coatings showed significantly lower dissolution in molten aluminium compared with the uncoated H13 steel. A Ti(Al,O)/Al₂O₃ composite coating was found to be a more effective protective coating than a TiAl(O)/Al₂O₃ composite coating due its greater resistance to molten aluminium attack.

text: The performance of thermally sprayed titanium based composite coatings in molten aluminium The service life of die and tool steels in contact with molten aluminium is important in the aluminium processing industry. This article describes an investigation of the efficiency of thermally sprayed Ti(Al,O)/Al₂O₃ and TiAl(O)/Al₂O₃ composite coatings in resisting aluminium soldering on H13 tool steel. The powder feedstocks for making the composite coatings were produced by high energy mechanical milling of a mixture of Al and TiO₂ powders using different molar ratios followed by a thermal reaction process. The feedstocks were then thermally sprayed using a high velocity oxygen fuel (HVOF) technique onto an H13 steel substrate to produce composite coatings. The performance of the coatings was assessed in terms of Al soldering and liquid metal corrosion resistance after immersing in molten aluminium at a temperature of 700 ± 10 °C. The results of this study showed that composite coatings have a potential to act as a physical barrier to prevent aluminium attack on H13 tool steel. The nature of Al attack on H13 tool steel changed from generalised to more localised attack with the thermally sprayed coating. A Ti(Al,O)/Al₂O₃ composite coating was not attacked by molten aluminium, however localised attack on a H13 tool steel substrate was found to be caused by molten metal penetration through defects in the coating. Composite coating TiAl(O)/Al₂O₃ was attacked by molten aluminium resulting in dissolution of the coating. Composite coatings showed significantly lower dissolution in molten aluminium compared with the uncoated H13 steel. A Ti(Al,O)/Al₂O₃ composite coating was found to be a more effective protective coating than a TiAl(O)/Al₂O₃ composite coating due its greater resistance to molten aluminium attack.

year: 2011

title: Addressing diversity: Race, ethnicity, and culture in the classroom

authors: Bishop, Russell

subjects: New Zealand

abstract: The widely accepted educational goals for Maori, established at the first Hui Taumata Matauranga held in 2001, are that Maori ought to be able to live as Maori, actively participate as citizens of the world, and enjoy both good health and high standards of living (Durie, 2001). Together with the government goals of equipping learners with twenty-first century skills and reducing systemic underachievement in education, these goals inform the new 2008-2012 Maoni Education Strategy, Ka Hikitia Managing for Success (Ministry of Education, 2007), which has as its main strategic outcome: Maori students enjoying education success as Maori. Within this frame, there are four student outcomes for Maori: learning to learn, making a distinctive cultural contribution, contributing to Te Ao Maori, and contributing to Aotearoa/New Zealand and the world.

text: Addressing diversity: Race, ethnicity, and culture in the classroom The widely accepted educational goals for Maori, established at the first Hui Taumata Matauranga held in 2001, are that Maori ought to be able to live as Maori, actively participate as citizens of the world, and enjoy both good health and high standards of living (Durie, 2001). Together with the government goals of equipping learners with twenty-first century skills and reducing systemic underachievement in education, these goals inform the new 2008-2012 Maoni Education Strategy, Ka Hikitia Managing for Success (Ministry of Education, 2007), which has as its main strategic outcome: Maori students enjoying education success as Maori. Within this frame, there are four student outcomes for Maori: learning to learn, making a distinctive cultural contribution, contributing to Te Ao Maori, and contributing to Aotearoa/New Zealand and the world.

year: 2009