title: Stochastic gradient trees

authors: Gouk, Henry

subjects: Decision tree induction

abstract: We present an algorithm for learning decision trees using stochastic gradient information as the source of supervision. In contrast to previous approaches to gradient-based tree learning, our method operates in the incremental learning setting rather than the batch learning setting, and does not make use of soft splits or require the construction of a new tree for every update. We demonstrate how one can apply these decision trees to different problems by changing only the loss function, using classification, regression, and multi-instance learning as example applications. In the experimental evaluation, our method performs similarly to standard incremental classification trees, outperforms state of the art incremental regression trees, and achieves comparable performance with batch multi-instance learning methods.

text: Stochastic gradient trees We present an algorithm for learning decision trees using stochastic gradient information as the source of supervision. In contrast to previous approaches to gradient-based tree learning, our method operates in the incremental learning setting rather than the batch learning setting, and does not make use of soft splits or require the construction of a new tree for every update. We demonstrate how one can apply these decision trees to different problems by changing only the loss function, using classification, regression, and multi-instance learning as example applications. In the experimental evaluation, our method performs similarly to standard incremental classification trees, outperforms state of the art incremental regression trees, and achieves comparable performance with batch multi-instance learning methods.

year: 2019

title: Experimental investigation of CFS to steel connection using self-drilling screws

authors: Anthony, Anu

abstract: Screws are one of the most used methods for joining structural steel to Cold Formed Steel (CFS). An improved substitute for conventional nail and bolt connections is self-drilling screws. The wings in the screws make it easier to drive the screw into the steel without the use of a pre-drilled hole. Given that joints are the primary means of transferring energy to a structure, it is especially crucial to comprehend the seismic behaviour of their connection. New Zealand, for example, is a country that primarily experiences seismic activity and builds its buildings using a combination of structural steel and CFS. Numerous research that looks into how structural joints behave under cyclic and monotonic loading conditions are available in the literature. However, the majority of these studies did not address the use of self-drilling screws in cyclic stress to link CFS to structural steel. Thus, by experimental testing, this research examines the load deformation and failure mechanisms of CFS and steel connections utilising screws under cyclic and monotonic loads. 
Tensile testing was done to evaluate the material's properties of steel. A total of 54 experimental investigations were conducted to determine the cyclic nature of the junction. The structural steel thickness (8mm, 12mm, 16mm, and 20mm), the CFS thickness (1.8mm), and the screw diameter (6.3mm hexagonal screw), and varying the number of screws (1 and 2) were considered in test program. The same samples were subjected to monotonic tests in order to determine the maximum and minimum displacement for the cyclic loading. A total of 24 tests were performed in order to acquire the values. The experiment's findings, including load deformation and the failure process, are identified. Based on the contrasting data, the cyclic nature of all the connections can be analysed to ascertain which is the most correct.
The New Zealand standard AS/NZS 4600:2018, which particularly addresses the screw spacing with each other and the distance from the screw to the edge of the specimen, will serve as the basis for both the assembly and the spacing of the structural joints. The loading procedures and the number of cycles employed for cyclic loading are detailed in the Federal Emergency Management Agency 461 (FEMA). Appropriate displacement amplitudes for cyclic tests were determined using the initial results from the monotonic tests. 
During the cyclic testing it could be found that most of the specimens failed due to bearing and tear out failure. There is an average increase of 56.77 % in capacity as the number of screws were increased from single screw to double screw connection.  As the steel thickness was increased as 8mm, 12mm, 16mm, and 20mm, the average capacity was reduced to 10.13%, 18.11%, 7.98% accordingly for a single screw connection. For double screw connection as the steel thickness was increased as 8mm,12mm, 16mm, and 20mm, the average capacity was increased to 0.79%, 4.91%, 2.15% accordingly.

text: Experimental investigation of CFS to steel connection using self-drilling screws Screws are one of the most used methods for joining structural steel to Cold Formed Steel (CFS). An improved substitute for conventional nail and bolt connections is self-drilling screws. The wings in the screws make it easier to drive the screw into the steel without the use of a pre-drilled hole. Given that joints are the primary means of transferring energy to a structure, it is especially crucial to comprehend the seismic behaviour of their connection. New Zealand, for example, is a country that primarily experiences seismic activity and builds its buildings using a combination of structural steel and CFS. Numerous research that looks into how structural joints behave under cyclic and monotonic loading conditions are available in the literature. However, the majority of these studies did not address the use of self-drilling screws in cyclic stress to link CFS to structural steel. Thus, by experimental testing, this research examines the load deformation and failure mechanisms of CFS and steel connections utilising screws under cyclic and monotonic loads. 
Tensile testing was done to evaluate the material's properties of steel. A total of 54 experimental investigations were conducted to determine the cyclic nature of the junction. The structural steel thickness (8mm, 12mm, 16mm, and 20mm), the CFS thickness (1.8mm), and the screw diameter (6.3mm hexagonal screw), and varying the number of screws (1 and 2) were considered in test program. The same samples were subjected to monotonic tests in order to determine the maximum and minimum displacement for the cyclic loading. A total of 24 tests were performed in order to acquire the values. The experiment's findings, including load deformation and the failure process, are identified. Based on the contrasting data, the cyclic nature of all the connections can be analysed to ascertain which is the most correct.
The New Zealand standard AS/NZS 4600:2018, which particularly addresses the screw spacing with each other and the distance from the screw to the edge of the specimen, will serve as the basis for both the assembly and the spacing of the structural joints. The loading procedures and the number of cycles employed for cyclic loading are detailed in the Federal Emergency Management Agency 461 (FEMA). Appropriate displacement amplitudes for cyclic tests were determined using the initial results from the monotonic tests. 
During the cyclic testing it could be found that most of the specimens failed due to bearing and tear out failure. There is an average increase of 56.77 % in capacity as the number of screws were increased from single screw to double screw connection.  As the steel thickness was increased as 8mm, 12mm, 16mm, and 20mm, the average capacity was reduced to 10.13%, 18.11%, 7.98% accordingly for a single screw connection. For double screw connection as the steel thickness was increased as 8mm,12mm, 16mm, and 20mm, the average capacity was increased to 0.79%, 4.91%, 2.15% accordingly.

year: 2025-02-22

title: A Relationships Framework for Organisational Responsiveness to Te Tiriti/Treaty of Waitangi in the Work of Groups and Organisations in the Community and the Public Sector of Aotearoa New Zealand

authors: Spelman, Anthony Cyril

subjects: Organisation Development

abstract: This thesis is focussed on the development and implementation of a Relationships Framework based on Te Tiriti/Treaty of Waitangi.  The Framework has been designed to enable working together between Tangata Whenua and Tangata Tiriti in the community and Public Sector in Aotearoa New Zealand.  Its development is explored and its implementation critiqued.  Within that Framework, an original organisation development tool based on a Tiriti/Treaty two-worldview approach is examined in terms of its potential to facilitate change in the operation and management of public life in Aotearoa New Zealand.
My aim is to establish an effective approach for working with worldview difference in the context of Tiriti/Treaty of Waitangi relationships and their implications.  I have a belief that Tangata Whenua are currently excluded from participating in processes that govern public life due to the dominance of Tangata Tiriti worldviews.  Therefore I am committed to making a contribution to a change in this dynamic so that Tangata Whenua views are not only heard but form an integral part of how the infrastructure of our public life is developed and managed. 
The Tiriti/Treaty of Waitangi Relationships Framework [The Framework] presented in the thesis is critiqued in two ways: i) through an examination of the concepts that inform it, and ii) by exploring six examples of its operation and further development in the community and public sector in Aotearoa New Zealand.  The Framework and the Tiriti/Treaty Two-worldview approach used to inform it has worked effectively in a variety of settings.  Through my research I show that organisation development of this type is complex.  It appears that there need be no fixed starting point in the development process within an organisation.  However all key elements of that process must eventually be addressed if effective relationships are to be achieved and the resulting organisational change is to be sustained.  Commitment to organisation development of this type is therefore long-term and requires a commitment to leading and supporting change in behaviour, systems and processes, and structures.

text: A Relationships Framework for Organisational Responsiveness to Te Tiriti/Treaty of Waitangi in the Work of Groups and Organisations in the Community and the Public Sector of Aotearoa New Zealand This thesis is focussed on the development and implementation of a Relationships Framework based on Te Tiriti/Treaty of Waitangi.  The Framework has been designed to enable working together between Tangata Whenua and Tangata Tiriti in the community and Public Sector in Aotearoa New Zealand.  Its development is explored and its implementation critiqued.  Within that Framework, an original organisation development tool based on a Tiriti/Treaty two-worldview approach is examined in terms of its potential to facilitate change in the operation and management of public life in Aotearoa New Zealand.
My aim is to establish an effective approach for working with worldview difference in the context of Tiriti/Treaty of Waitangi relationships and their implications.  I have a belief that Tangata Whenua are currently excluded from participating in processes that govern public life due to the dominance of Tangata Tiriti worldviews.  Therefore I am committed to making a contribution to a change in this dynamic so that Tangata Whenua views are not only heard but form an integral part of how the infrastructure of our public life is developed and managed. 
The Tiriti/Treaty of Waitangi Relationships Framework [The Framework] presented in the thesis is critiqued in two ways: i) through an examination of the concepts that inform it, and ii) by exploring six examples of its operation and further development in the community and public sector in Aotearoa New Zealand.  The Framework and the Tiriti/Treaty Two-worldview approach used to inform it has worked effectively in a variety of settings.  Through my research I show that organisation development of this type is complex.  It appears that there need be no fixed starting point in the development process within an organisation.  However all key elements of that process must eventually be addressed if effective relationships are to be achieved and the resulting organisational change is to be sustained.  Commitment to organisation development of this type is therefore long-term and requires a commitment to leading and supporting change in behaviour, systems and processes, and structures.

year: 2013