title: Variations of radiocarbon in tree rings: southern hemisphere offset preliminary results

authors: McCormac, F.G.

subjects: radiocarbon

abstract: The Queen's University of Belfast, Northern Ireland and University of Waikato, Hamilton, New Zealand radiocarbon laboratories have undertaken a series of high-precision measurements on decadal samples of dendrochronologically dated oak (Quercus patrea) and cedar (Libocedrus bidwillii) from Great Britain and New Zealand, respectively. The results show a real atmospheric offset of 3.4 ± 0.6% (27.2 ± 4.7 ¹⁴C yr) between the two locations for the interval AD 1725 to AD 1885, with the Southern Hemisphere being depleted in ¹⁴C. This result is less than the value currently used to correct Southern Hemisphere calibrations, possibly indicating a gradient in Δ¹⁴C within the Southern Hemisphere.

text: Variations of radiocarbon in tree rings: southern hemisphere offset preliminary results The Queen's University of Belfast, Northern Ireland and University of Waikato, Hamilton, New Zealand radiocarbon laboratories have undertaken a series of high-precision measurements on decadal samples of dendrochronologically dated oak (Quercus patrea) and cedar (Libocedrus bidwillii) from Great Britain and New Zealand, respectively. The results show a real atmospheric offset of 3.4 ± 0.6% (27.2 ± 4.7 ¹⁴C yr) between the two locations for the interval AD 1725 to AD 1885, with the Southern Hemisphere being depleted in ¹⁴C. This result is less than the value currently used to correct Southern Hemisphere calibrations, possibly indicating a gradient in Δ¹⁴C within the Southern Hemisphere.

year: 1998

title: An algorithmic approach to OpenFlow ruleset transformation

authors: Sanger, Richard

abstract: In an ideal development cycle for an OpenFlow application, a developer designs a pipeline to suit their application's needs and installs rules to that pipeline. Their application will run on any OpenFlow switch, whether software or hardware based. A network operator deploying this application would assess their network's requirements and purchase OpenFlow hardware to meet these requirements; such as bandwidth, port density, and flow table size. In reality, this level of interoperability does not exist as many OpenFlow switches are built on a fixed-function pipeline. Fixed-function pipelines limit the matches and actions available to rules depending on the table, but in doing so make more efficient use of expensive hardware resources such as TCAM.

This thesis investigates improving OpenFlow device interoperability by developing a method to rewrite existing rulesets to new complex fixed-function pipelines. Additionally, this thesis developed the tools to assess and verify the interoperability and equivalence of OpenFlow rulesets and pipelines. 

This thesis developed a library and tools for working with descriptions of fixed-function pipelines, specifically, the Table Type Pattern description. This library provides a method to check if an existing ruleset is compatible with a new pipeline. Additionally, this thesis designed and implemented a pragmatic approach to compare if the forwarding behaviour of two OpenFlow 1.3 rulesets is equivalent. Equivalence checking provides a tool to verify that an OpenFlow application rewritten to program a new pipeline maintains the correct forwarding behaviour.

Finally, this thesis investigates the problem of algorithmically rewriting an existing OpenFlow ruleset, programmed by an existing application, to fit a different fixed-function pipeline. Solving this problem allows an OpenFlow application to be written once and run on any OpenFlow switch. This research aimed to solve this problem in a comprehensive manner that did not rely on the target pipeline supporting features such as OpenFlow metadata. This thesis developed and implemented a general method to convert an OpenFlow 1.3 to a complex constrained fixed-function.

text: An algorithmic approach to OpenFlow ruleset transformation In an ideal development cycle for an OpenFlow application, a developer designs a pipeline to suit their application's needs and installs rules to that pipeline. Their application will run on any OpenFlow switch, whether software or hardware based. A network operator deploying this application would assess their network's requirements and purchase OpenFlow hardware to meet these requirements; such as bandwidth, port density, and flow table size. In reality, this level of interoperability does not exist as many OpenFlow switches are built on a fixed-function pipeline. Fixed-function pipelines limit the matches and actions available to rules depending on the table, but in doing so make more efficient use of expensive hardware resources such as TCAM.

This thesis investigates improving OpenFlow device interoperability by developing a method to rewrite existing rulesets to new complex fixed-function pipelines. Additionally, this thesis developed the tools to assess and verify the interoperability and equivalence of OpenFlow rulesets and pipelines. 

This thesis developed a library and tools for working with descriptions of fixed-function pipelines, specifically, the Table Type Pattern description. This library provides a method to check if an existing ruleset is compatible with a new pipeline. Additionally, this thesis designed and implemented a pragmatic approach to compare if the forwarding behaviour of two OpenFlow 1.3 rulesets is equivalent. Equivalence checking provides a tool to verify that an OpenFlow application rewritten to program a new pipeline maintains the correct forwarding behaviour.

Finally, this thesis investigates the problem of algorithmically rewriting an existing OpenFlow ruleset, programmed by an existing application, to fit a different fixed-function pipeline. Solving this problem allows an OpenFlow application to be written once and run on any OpenFlow switch. This research aimed to solve this problem in a comprehensive manner that did not rely on the target pipeline supporting features such as OpenFlow metadata. This thesis developed and implemented a general method to convert an OpenFlow 1.3 to a complex constrained fixed-function.

year: 2020

title: Donna Awatere’s Māori Sovereignty: Reflections on White Supremacy and the Racialization of Crime Control and Surveillance in Aotearoa New Zealand

authors: Dawson, Brian

abstract: Donna Awatere’s examination of whiteness within the Aotearoa New Zealand context, specifically white cultural imperialism, has largely been ignored in academic scholarship. For her, white culture, and its articulation through governance and policy, is the starting point and lens to understanding and addressing historical and contemporary Māori dispossession and ensuing strategies of racialized surveillance, control, and containment. In this essay, we argue that Awatere’s attention to past forms of genocide – mapping them to emerging forms of state confinement of Māori, which engender genocidal characteristics, and problematizing “whiteness” – situates the book Māori Sovereignty as an important text in the field of criminal justice, especially that which manifests in settler-colonial contexts.

text: Donna Awatere’s Māori Sovereignty: Reflections on White Supremacy and the Racialization of Crime Control and Surveillance in Aotearoa New Zealand Donna Awatere’s examination of whiteness within the Aotearoa New Zealand context, specifically white cultural imperialism, has largely been ignored in academic scholarship. For her, white culture, and its articulation through governance and policy, is the starting point and lens to understanding and addressing historical and contemporary Māori dispossession and ensuing strategies of racialized surveillance, control, and containment. In this essay, we argue that Awatere’s attention to past forms of genocide – mapping them to emerging forms of state confinement of Māori, which engender genocidal characteristics, and problematizing “whiteness” – situates the book Māori Sovereignty as an important text in the field of criminal justice, especially that which manifests in settler-colonial contexts.

year: 2023-07-27