208 research outputs found
An energy efficient time-mode digit classification neural network implementation
No full textThis paper presents the design of an ultra-low energy neural network that uses time-mode signal processing). Handwritten digit classification using a single-layer artificial neural network (ANN) with a Softmin-based activation function is described as an implementation example. To realize time-mode operation, the presented design makes use of monostable multivibrator-based multiplying analogue-to-time converters, fixed-width pulse generators and basic digital gates. The time-mode digit classification ANN was designed in a standard CMOS 0.18 μm IC process and operates from a supply voltage of 0.6 V. The system operates on the MNIST database of handwritten digits with quantized neuron weights and has a classification accuracy of 88%, which is typical for single-layer ANNs, while dissipating 65.74 pJ per classification with a speed of 2.37 k classifications per second. This article is part of the theme issue 'Harmonizing energy-autonomous computing and intelligence'.Accepted Author ManuscriptBio-Electronic
Feather forensics: tracing the origins of parrots in wildlife trade with stable isotopes and citizen science
No full textFirst published: 28 January 2025To supply the high demand for wildlife as exotic pets, animals may be illegally and unsustainably harvested from the wild and laundered as captive bred. Consequently, there is considerable interest in wildlife forensic tools that are capable of verifying captive origins. Stable isotope analysis is an emerging tool for verifying captive and wild origins by identifying key differences in dietary intake. While previous studies have effectively classified origins by differences in their stable isotope ratios, these studies are often limited to species with small population sizes and geographic ranges, masking potential variation caused by different environments and diets. We tested the accuracy of stable carbon (δ13C) and nitrogen (δ15N) isotope analyses to verify captive and wild origins using bird species that are common in pet trade, and have widespread distributions and generalist diets. Through a citizen science project in South Australia, we collected naturally dropped feathers from four native Australian cockatoo (Cacatuidae) species: Galahs (Eolophus roseicapilla); and three Cacatua species; sulphur-crested cockatoos (Cacatua galerita), little corellas (C. sanguinea) and long-billed Corellas (C. tenuirostris). We compared isotope ratios of captive and wild birds and calculated the classification accuracy of using stable isotopes to determine origin. Stable isotope values were significantly different between captive and wild adult birds, where captive birds had significantly higher δ13C and δ15N than wild birds. Captive and wild origins of individual Eolophus could be classified with relatively high accuracy (88%). However, Cacatua showed low repeatability and large overlaps between the origin groups, which reduced their classification accuracy (74%). Stable isotope analysis can be a potential classification tool in wildlife trade; however, before on-ground implementation, we recommend that variation from different diets across a species’ geographical range be more thoroughly investigated to better understand and explain the full range of possible δ13C and δ15N values.K. G. W. Hill, S. Delean, T. Hall, J. J. Tyler, O. C. Stringham, P. Casse
Who's a pretty bird? Predicting the traded abundance of bird species in Australian online pet trade
No full textPublished online: 16 December 2023The increasing popularity of online commerce provides a new opportunity to investigate and quantify the dynamics of pet trade. Understanding these dynamics, including relationships between species characteristics and a species’ relative abundance in trade, can assist in informing trade regulation for conservation and biosecurity. We identified the leading correlates behind the abundance in the Australian pet trade of parrot (Psittaciformes) and passerine (Passeriformes) species. We examined 14,000 online sales of parrots and passerines collected from a popular online Australian marketplace in 2019 (representing 235 species) using an automated data collection method. We identified the characteristics that correlated with online species abundance; including (i) breeding and handling requirements; (ii) trade and availability; and (iii) appearance and behaviour. We found 55% of parrot species and 64% of passerine species traded online were non-native to Australia; of these, 81% and 85% respectively have an extreme risk of establishing invasive populations. Species abundance of both orders was correlated with cheaper prices, which is also associated with a higher invasion risk. Trade in parrots was correlated with attractive birdsongs, being easier to care for, and a preference for native Australian species. Passerine abundance was correlated with attractive plumage colour and, to a lesser extent, the availability of colour mutations and smaller geographic range sizes. These results, combined with an understanding of consumer behaviour and international trends, may help predict which species will become abundant in domestic trade in the future, and identify current and future invasion risks to assist in environmental biosecurity efforts.Katherine G. W. Hill, Oliver C. Stringham, Stephanie Moncayo, Adam Toomes, Jonathan J. Tyler, Phillip Cassey, Steven Delea
Identifying recent captive escapees of Rainbow Lorikeets (Trichoglossus moluccanus) at different stages of the pet-release pathway
No full textIntroduction: Rainbow Lorikeets (Trichoglossus moluccanus) are a highly desirable bird in Australian pet trade and consequently have established invasive populations outside their native range. These birds are aggressive, outcompete native species, and cause significant damage to agriculture. Invasive populations have not been impacted by existing management practices, and it is unclear if their persistence is due to their high reproductive success in the wild, or from regular escapes from captivity. Methods: We tested the ability of stable isotope analysis to identify recently escaped captive Rainbow Lorikeets in wild populations within Australia. We compared the stable carbon (δ¹³C) and nitrogen (δ¹⁵N) isotopes of captive birds to three wild populations at different stages of the pet-release pathway: (i) birds within their native distribution; (ii) a newly established population; and (iii) a large invasive population. Results: We found evidence of two escaped captive birds in the newly established population due to the higher and more variable δ¹³C, which is likely driven by the consumption of nectar supplements. The invasive population had a similar isotopic niche area to the native population; potentially indicating the invasive birds have adapted to the environment and learnt to consume a large variety of local food sources, therefore reducing the effectiveness of detecting recent escapees. Discussion: Therefore, for contained wild populations with small isotopic niches, stable isotope analysis can be a useful tool to identify captive escapees and can inform management of invasive species incursions.Katherine G.W. Hill, Steven Delean, Susan A. Robinson, Tony Hall, Jonathan J. Tyler, Oliver C. Stringham, and Phillip Casse
Economising mooring and guiding constructions at lock approaches in inland waterways – the Dutch experience
No full textAs a result of diminishing budgets for maintenance, the Dutch waterway authority Rijkswaterstaat is amongst others in search for economizing infrastructural facilities for commercial inland vessels along its waterways. One type of those facilities are the mooring constructions for line up- and waiting areas at lock approaches. Another type are the guiding constructions for entering the lock chamber, the so called funnels. The mooring and guiding constructions basicly exist of piles, connected by crossbeams and can be designed in either a fixed or a floating version, depending on the fall of the waterway.Hydraulic EngineeringCivil Engineering and Geoscience
The role of classification and reference vessels in the design of inland fairways for commercial vessels – contribution to the Workshop of WG 141 Design Guidelines for Inland Waterways
No full textThe Pianc WG 141 is proceeding in the conception of Design Guidelines for Inland Waterways. WG 141 aims to produce its first draft in the end of 2015. Part of the forseen content are classification of waterways and the object of reference vessels. The role of those subjects will be presented and discussed in the Workshop, that WG 141 will give during the Smart Rivers 2015 Conference, scheduled at the 8th of September.Hydraulic EngineeringCivil Engineering and Geoscience
The Interconnected Fluidized Bed reactor - for gas/solids regenerative processes
No full textApplied Science
Richtlijnen Vaarwegen 2020
No full textDe Richtlijnen Vaarwegen bundelen de Nederlandse kennis op het gebied van het ontwerp en de inrichting van vaarwegen, zowel vaarwegvakken als havens, bruggen en sluizen. De richtlijnen geven aanwijzingen voor het kiezen van een maatgevend schip en maatgevende hydraulische randvoorwaarden voor zowel beroeps- als recreatievaart. De richtlijnen gelden voor vaarwegen tot en met CEMT-klasse VI. Door vaarwegen volgens dezelfde richtlijnen te ontwerpen, ontstaat een beter samenhangend vaarwegennetwerk
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