title: Automatic Weighing for Dry Stock

authors: Smialowski, Grzegorz

subjects: weighing

abstract: The aim of the research was to develop an accurate weight estimation algorithm for dry stock cattle using unsupervised walk-over equipment and to investigate the accuracy of the dairy cow algorithm for dry stock animals. Several customers and research organisations requested a suitable product for weighing dry stock, similar to the automatic weighing system for dairy cows. The development of the algorithm had to take into account the erratic behaviour of dry stock cattle. An additional requirement for the research was to improve cost effectiveness of the existing system, by removing the need for the lead-on platform.
Data was collected from a series of dry stock herds, as they walked over the existing dairy cow walk-over weighing (WOW) platform, in either a paddock or a stockyard. All dry stock cattle were static weighed before walking over the WOW to obtain an accurate true weight of the animal. The weight estimations produced by the dairy cow algorithm were recorded and the raw load cell data was captured. The raw load cell data was then used to devise a new algorithm specifically for dry stock cattle. The new algorithm was tested against the collected load cell data from various herds. The dairy cow algorithm results were used to compare the accuracy of the existing algorithm on dry stock cattle.
The new devised algorithm used a threshold to locate a rough start and end point for each walk-over event. The data between the initial start and end points was processed to locate the period which had the full weight of the cattle located on the weighing platform. The algorithm estimated the weight of the animal from the data between these points.
It was found that the dairy cow algorithm was nearing the required accuracy, but was not able to determine weights for the majority of the animals. The new algorithm devised for dry stock cattle was unable to obtain an improvement in accuracy, but was able to estimate weights for a greater proportion of the cattle. Additionally the new algorithm was successful in eliminating the need for the lead-on platform for detecting animals.

text: Automatic Weighing for Dry Stock The aim of the research was to develop an accurate weight estimation algorithm for dry stock cattle using unsupervised walk-over equipment and to investigate the accuracy of the dairy cow algorithm for dry stock animals. Several customers and research organisations requested a suitable product for weighing dry stock, similar to the automatic weighing system for dairy cows. The development of the algorithm had to take into account the erratic behaviour of dry stock cattle. An additional requirement for the research was to improve cost effectiveness of the existing system, by removing the need for the lead-on platform.
Data was collected from a series of dry stock herds, as they walked over the existing dairy cow walk-over weighing (WOW) platform, in either a paddock or a stockyard. All dry stock cattle were static weighed before walking over the WOW to obtain an accurate true weight of the animal. The weight estimations produced by the dairy cow algorithm were recorded and the raw load cell data was captured. The raw load cell data was then used to devise a new algorithm specifically for dry stock cattle. The new algorithm was tested against the collected load cell data from various herds. The dairy cow algorithm results were used to compare the accuracy of the existing algorithm on dry stock cattle.
The new devised algorithm used a threshold to locate a rough start and end point for each walk-over event. The data between the initial start and end points was processed to locate the period which had the full weight of the cattle located on the weighing platform. The algorithm estimated the weight of the animal from the data between these points.
It was found that the dairy cow algorithm was nearing the required accuracy, but was not able to determine weights for the majority of the animals. The new algorithm devised for dry stock cattle was unable to obtain an improvement in accuracy, but was able to estimate weights for a greater proportion of the cattle. Additionally the new algorithm was successful in eliminating the need for the lead-on platform for detecting animals.

year: 2013

title: Macroinvertebrate–pressure relationships in boatable New Zealand rivers: Influence of underlying environment and sampling substrate

authors: Collier, Kevin J.

subjects: bioassessment

abstract: Responses of macroinvertebrate communities to human pressure are poorly known in large rivers compared with wadeable streams, in part because of variable substrate composition and the need to disentangle pressure responses from underlying natural environmental variation. To investigate the interaction between these factors, we sampled macroinvertebrates from the following: (i) submerged wood; (ii) littoral substrates < 0.8 m deep; and (iii) inorganic substrates in deep water (> 1.5 m) benthic habitats in eleven 6th- or 7th-order New Zealand rivers spanning a catchment vegetation land cover gradient. Cluster analysis identified primary site groupings reflecting regional environmental characteristics and secondary groupings for moderate gradient rivers reflecting the extent of catchment native vegetation cover. Low pressure sites with high levels of native vegetation had higher habitat quality and higher percentages of several Ephemeroptera and Trichoptera taxa than sites in developed catchments, whereas developed sites were more typically dominated by Diptera, Mollusca and other Trichoptera. Partial regression analysis indicated that the combination of underlying environment and human pressure accounted for 77–89% of the variation in Ephemeroptera, Trichoptera and Plecoptera taxa richness, %Diptera and %Mollusca, with human pressure explaining more variance than underlying environment for %Mollusca. Analysis of replicate deepwater and littoral samples from moderate gradient sites at the upper and lower ends of the pressure gradient indicated that total Trichoptera and Diptera richness and %Diptera responded to land use differences in these boatable river catchments. Responses to human pressure were substrate specific with the combination of littoral and deepwater substrates providing the most consistent response and yielding the highest number of taxa. These results indicate that multiple substrate sampling is required to document the biodiversity and condition of boatable river macroinvertebrate communities and that spatial variation in the underlying natural environment needs to be accounted for when interpreting pressure–response relationships.

text: Macroinvertebrate–pressure relationships in boatable New Zealand rivers: Influence of underlying environment and sampling substrate Responses of macroinvertebrate communities to human pressure are poorly known in large rivers compared with wadeable streams, in part because of variable substrate composition and the need to disentangle pressure responses from underlying natural environmental variation. To investigate the interaction between these factors, we sampled macroinvertebrates from the following: (i) submerged wood; (ii) littoral substrates < 0.8 m deep; and (iii) inorganic substrates in deep water (> 1.5 m) benthic habitats in eleven 6th- or 7th-order New Zealand rivers spanning a catchment vegetation land cover gradient. Cluster analysis identified primary site groupings reflecting regional environmental characteristics and secondary groupings for moderate gradient rivers reflecting the extent of catchment native vegetation cover. Low pressure sites with high levels of native vegetation had higher habitat quality and higher percentages of several Ephemeroptera and Trichoptera taxa than sites in developed catchments, whereas developed sites were more typically dominated by Diptera, Mollusca and other Trichoptera. Partial regression analysis indicated that the combination of underlying environment and human pressure accounted for 77–89% of the variation in Ephemeroptera, Trichoptera and Plecoptera taxa richness, %Diptera and %Mollusca, with human pressure explaining more variance than underlying environment for %Mollusca. Analysis of replicate deepwater and littoral samples from moderate gradient sites at the upper and lower ends of the pressure gradient indicated that total Trichoptera and Diptera richness and %Diptera responded to land use differences in these boatable river catchments. Responses to human pressure were substrate specific with the combination of littoral and deepwater substrates providing the most consistent response and yielding the highest number of taxa. These results indicate that multiple substrate sampling is required to document the biodiversity and condition of boatable river macroinvertebrate communities and that spatial variation in the underlying natural environment needs to be accounted for when interpreting pressure–response relationships.

year: 2012

title: Working at the interface: Indigenous students’ experience of undertaking doctoral studies in Aotearoa New Zealand

authors: McKinley, Elizabeth

subjects: Māori

abstract: Māori (indigenous)¹ doctoral students in Aotearoa New Zealand face challenges not usually experienced by other doctoral candidates. We draw on data from in-depth interviews with 38 Māori doctoral candidates and argue that because of the tensions between academic disciplinary knowledge frameworks and knowledge drawn from te ao Māori (the Māori world) indigenous students have additional cultural, academic, and personal demands placed on them while aiming to produce research theses that meet conventional standards of academic scholarship. Complex methodological and ethical issues also emerge in undertaking doctoral research projects situated at the interface of academy and indigenous communities. Moreover, Māori students experience various degrees of tension between their sometimes strong cultural identities and their emerging and, therefore, less certain identities as researchers and scholars.

text: Working at the interface: Indigenous students’ experience of undertaking doctoral studies in Aotearoa New Zealand Māori (indigenous)¹ doctoral students in Aotearoa New Zealand face challenges not usually experienced by other doctoral candidates. We draw on data from in-depth interviews with 38 Māori doctoral candidates and argue that because of the tensions between academic disciplinary knowledge frameworks and knowledge drawn from te ao Māori (the Māori world) indigenous students have additional cultural, academic, and personal demands placed on them while aiming to produce research theses that meet conventional standards of academic scholarship. Complex methodological and ethical issues also emerge in undertaking doctoral research projects situated at the interface of academy and indigenous communities. Moreover, Māori students experience various degrees of tension between their sometimes strong cultural identities and their emerging and, therefore, less certain identities as researchers and scholars.

year: 2011