title: Partial unfolding for compositional nonblocking verification of extended finite-state machines

authors: Mohajerani, Sahar

abstract: This working paper describes a framework for compositional nonblocking veriﬁcation of reactive systems modelled as extended ﬁnite-state machines. The nonblocking property can capture the absence of livelocks and deadlocks in concurrent systems. Compositional veriﬁcation is shown in previous work to be effective to verify this property for large discrete event systems. Here, these results are applied to extended ﬁnite-state machines communicating via shared memory.
The model to be veriﬁed is composed gradually, simplifying components through abstraction at each step, while conﬂict equivalence guarantees that the ﬁnal veriﬁcation result is the same as it would have been for the non-abstracted model. The working paper concludes with an example showing the potential of compositional veriﬁcation to achieve substantial state-space reduction.

text: Partial unfolding for compositional nonblocking verification of extended finite-state machines This working paper describes a framework for compositional nonblocking veriﬁcation of reactive systems modelled as extended ﬁnite-state machines. The nonblocking property can capture the absence of livelocks and deadlocks in concurrent systems. Compositional veriﬁcation is shown in previous work to be effective to verify this property for large discrete event systems. Here, these results are applied to extended ﬁnite-state machines communicating via shared memory.
The model to be veriﬁed is composed gradually, simplifying components through abstraction at each step, while conﬂict equivalence guarantees that the ﬁnal veriﬁcation result is the same as it would have been for the non-abstracted model. The working paper concludes with an example showing the potential of compositional veriﬁcation to achieve substantial state-space reduction.

year: 2013-01-30

title: Spectral analysis of seasonality in tourism demand

authors: Chan, Felix

subjects: Fast Fourier Transform

abstract: This paper aims to analyse the seasonality in New Zealand tourism demand from Australia and the USA using spectral analysis. Tourism demand is divided into four different categories depending on the tourists’ visiting purposes as registered in the customs cards upon their arrivals in New Zealand. Spectral analysis based on the sample from January 1980 to December 2007 revealed that different travel purposes share similar cyclical components but their contributions to the total variation in tourism demand differ between travel purposes and markets. More importantly, the results show that analysing aggregated data is often not sufficient to reveal the underlying seasonal patterns of tourist arrivals and policy makers would benefit greatly by analysing disaggregated data rather than relying on the analysis of aggregated data alone.

text: Spectral analysis of seasonality in tourism demand This paper aims to analyse the seasonality in New Zealand tourism demand from Australia and the USA using spectral analysis. Tourism demand is divided into four different categories depending on the tourists’ visiting purposes as registered in the customs cards upon their arrivals in New Zealand. Spectral analysis based on the sample from January 1980 to December 2007 revealed that different travel purposes share similar cyclical components but their contributions to the total variation in tourism demand differ between travel purposes and markets. More importantly, the results show that analysing aggregated data is often not sufficient to reveal the underlying seasonal patterns of tourist arrivals and policy makers would benefit greatly by analysing disaggregated data rather than relying on the analysis of aggregated data alone.

year: 2010

title: Developing an integrated ocean observing system for New Zealand

authors: O'Callaghan, J

subjects: Science & Technology

abstract: New Zealand (NZ) is an island nation with stewardship of an ocean twenty times larger than its land area. While the challenges facing NZ's ocean are similar to other maritime countries, no coherent national plan exists that meets the needs of scientists, stakeholders or kaitiakitanga (guardianship) of NZ's ocean in a changing climate. The NZ marine science community used the OceanObs'19 white paper to establish a framework and implementation plan for a collaborative NZ ocean observing system (NZ-OOS). Co-production of ocean knowledge with Māori will be embedded in this national strategy for growing a sustainable, blue economy for NZ. The strengths of an observing system for a relatively small nation come from direct connections between the science impetus through to users and stakeholders of an NZ-OOS. The community will leverage off existing ocean observations to optimize effort and resources in a system that has historically made limited investment in ocean observing. The goal of the community paper will be achieved by bringing together oceanographers, data scientists and marine stakeholders to develop an NZ-OOS that provides best knowledge and tools to the sectors of society that use or are influenced by the ocean.

text: Developing an integrated ocean observing system for New Zealand New Zealand (NZ) is an island nation with stewardship of an ocean twenty times larger than its land area. While the challenges facing NZ's ocean are similar to other maritime countries, no coherent national plan exists that meets the needs of scientists, stakeholders or kaitiakitanga (guardianship) of NZ's ocean in a changing climate. The NZ marine science community used the OceanObs'19 white paper to establish a framework and implementation plan for a collaborative NZ ocean observing system (NZ-OOS). Co-production of ocean knowledge with Māori will be embedded in this national strategy for growing a sustainable, blue economy for NZ. The strengths of an observing system for a relatively small nation come from direct connections between the science impetus through to users and stakeholders of an NZ-OOS. The community will leverage off existing ocean observations to optimize effort and resources in a system that has historically made limited investment in ocean observing. The goal of the community paper will be achieved by bringing together oceanographers, data scientists and marine stakeholders to develop an NZ-OOS that provides best knowledge and tools to the sectors of society that use or are influenced by the ocean.

year: 2019-03-26