title: Shape predicates allow unbounded verification of linearizability using canonical abstraction

authors: Friggens, David

subjects: canonical abstraction

abstract: Canonical abstraction is a static analysis technique that represents states as 3-valued logical structures, and is able to construct finite representations of systems with infinite statespaces for verification. The granularity of the abstraction can be altered by the definition of instrumentation predicates, which derive their meaning from other predicates. We introduce shape predicates for preserving certain structures of the state during abstraction. We show that shape predicates allow linearizability to be verified for concurrent data structures using canonical abstraction alone, and use the approach to verify a stack and two queue algorithms. This contrasts with previous efforts to verify linearizability with canonical abstraction, which have had to employ other techniques as well.

text: Shape predicates allow unbounded verification of linearizability using canonical abstraction Canonical abstraction is a static analysis technique that represents states as 3-valued logical structures, and is able to construct finite representations of systems with infinite statespaces for verification. The granularity of the abstraction can be altered by the definition of instrumentation predicates, which derive their meaning from other predicates. We introduce shape predicates for preserving certain structures of the state during abstraction. We show that shape predicates allow linearizability to be verified for concurrent data structures using canonical abstraction alone, and use the approach to verify a stack and two queue algorithms. This contrasts with previous efforts to verify linearizability with canonical abstraction, which have had to employ other techniques as well.

year: 2014

title: Boat electrofishing survey of the lower Waikato River and its tributaries

authors: Hicks, Brendan J.

subjects: New Zealand

abstract: We conducted the first electrofishing boat survey of the lower Waikato River and its tributaries between 8 and 15 February 2005. We caught 2,915 fish comprising seven introduced and six native fish species in 5.63 km of fished length from a total of 27 sites. Assuming that the bow-mounted anodes caught fish within a 1 m radius, the width fished was 4 m, and the total area fished was 22,520 m² or 2.252 ha.
Common smelt were the most numerous species caught (mean density 9.3 fish 100 m⁻²), followed by koi carp (mean density 1.7 fish 100 m⁻²) and goldfish (mean density 1.4 fish 100 m⁻²). Relatively few longfin eels, trout, bullies, and torrentfish were caught. In addition, three koi carp-goldfish hybrids were caught.

Koi carp comprised 285 kg, or 69% (range 0-97% per site) of the 410 kg of fish caught. The majority of koi carp were caught in Zones 2-4, where they occurred in all habitats except mid-channel sand bars. Koi carp biomasses up to 124 g m⁻² were associated with willow fringed and macrophyte beds. Biomass is more accurate reflection of the potential ecological impact of koi carp than their density. 

Adult trout were found only in the confluence habitats of Zone 1; all were brown trout except for one rainbow trout caught at LW007. Grey mullet comprised the greatest biomass of any native fish species, and shortfin eels, through widespread, did not comprise a high biomass. Only one torrentfish was found; this small juvenile (36 mm TL) was caught on a mid-channel bar at Mercer (site LW035).

Koi carp size increased with distance downstream, suggesting that the upper zones were more important for rearing than the lower river. The mean biomass for koi carp for all sites was 16 g m⁻², but previous results suggest that 21-73% of the total population estimate is caught on the first removal, depending on water visibility. As we fished over the area at each site only once, the estimates in this survey represent a minimum abundance, and true population sizes are likely to be 1.4-4.8 times greater. Of ecological concern for the Waikato region is the dominance of the fish biomass by introduced koi carp, which have a deleterious impace on aquatic habitats.

The fish data have been entered into NIWA’s New Zealand Freshwater Fish Database as card numbers 25,836 to 25,862.

text: Boat electrofishing survey of the lower Waikato River and its tributaries We conducted the first electrofishing boat survey of the lower Waikato River and its tributaries between 8 and 15 February 2005. We caught 2,915 fish comprising seven introduced and six native fish species in 5.63 km of fished length from a total of 27 sites. Assuming that the bow-mounted anodes caught fish within a 1 m radius, the width fished was 4 m, and the total area fished was 22,520 m² or 2.252 ha.
Common smelt were the most numerous species caught (mean density 9.3 fish 100 m⁻²), followed by koi carp (mean density 1.7 fish 100 m⁻²) and goldfish (mean density 1.4 fish 100 m⁻²). Relatively few longfin eels, trout, bullies, and torrentfish were caught. In addition, three koi carp-goldfish hybrids were caught.

Koi carp comprised 285 kg, or 69% (range 0-97% per site) of the 410 kg of fish caught. The majority of koi carp were caught in Zones 2-4, where they occurred in all habitats except mid-channel sand bars. Koi carp biomasses up to 124 g m⁻² were associated with willow fringed and macrophyte beds. Biomass is more accurate reflection of the potential ecological impact of koi carp than their density. 

Adult trout were found only in the confluence habitats of Zone 1; all were brown trout except for one rainbow trout caught at LW007. Grey mullet comprised the greatest biomass of any native fish species, and shortfin eels, through widespread, did not comprise a high biomass. Only one torrentfish was found; this small juvenile (36 mm TL) was caught on a mid-channel bar at Mercer (site LW035).

Koi carp size increased with distance downstream, suggesting that the upper zones were more important for rearing than the lower river. The mean biomass for koi carp for all sites was 16 g m⁻², but previous results suggest that 21-73% of the total population estimate is caught on the first removal, depending on water visibility. As we fished over the area at each site only once, the estimates in this survey represent a minimum abundance, and true population sizes are likely to be 1.4-4.8 times greater. Of ecological concern for the Waikato region is the dominance of the fish biomass by introduced koi carp, which have a deleterious impace on aquatic habitats.

The fish data have been entered into NIWA’s New Zealand Freshwater Fish Database as card numbers 25,836 to 25,862.

year: 2005

title: Representations of te reo Māori and te ao Māori in a translingual picturebook: How my Koro became a Star

authors: Barbour, Julie Renee

subjects: Indigenous language and culture

abstract: While English is the most commonly used language in Aotearoa New Zealand, it is a multilingual nation with two languages recognised as official: te reo Māori (the Māori language) and New Zealand Sign Language. The English language is dominant in children’s literature published in Aotearoa New Zealand, but since the 1980s there has been an increase in the number of picturebooks featuring two languages, te reo Māori and English. Previous work has explored how representations of te reo Māori and English in pukapuka pikitia reorua (dual language picturebooks) in Aotearoa reflect changing attitudes towards the two languages. In this article, we focus particularly on Brianne Te Paa and Story Hemi-Morehouse’s picturebook How my Koro became a Star. Originally written in te reo Māori, this multi-award winning picturebook is located at the beginning of Matariki, the Māori New Year celebration. In a move away from the linguistic analysis of te reo Māori being ‘borrowed’ by English, we consider how storytellers like Te Paa weave Māori language together with English in a translingual publication, supporting reader comprehension of Māori vocabulary and cultural meanings through embedded illustrations and explanations, inviting the curious reader to learn beyond the story.

text: Representations of te reo Māori and te ao Māori in a translingual picturebook: How my Koro became a Star While English is the most commonly used language in Aotearoa New Zealand, it is a multilingual nation with two languages recognised as official: te reo Māori (the Māori language) and New Zealand Sign Language. The English language is dominant in children’s literature published in Aotearoa New Zealand, but since the 1980s there has been an increase in the number of picturebooks featuring two languages, te reo Māori and English. Previous work has explored how representations of te reo Māori and English in pukapuka pikitia reorua (dual language picturebooks) in Aotearoa reflect changing attitudes towards the two languages. In this article, we focus particularly on Brianne Te Paa and Story Hemi-Morehouse’s picturebook How my Koro became a Star. Originally written in te reo Māori, this multi-award winning picturebook is located at the beginning of Matariki, the Māori New Year celebration. In a move away from the linguistic analysis of te reo Māori being ‘borrowed’ by English, we consider how storytellers like Te Paa weave Māori language together with English in a translingual publication, supporting reader comprehension of Māori vocabulary and cultural meanings through embedded illustrations and explanations, inviting the curious reader to learn beyond the story.

year: 2025