title: Superintegrability and higher-order constants for classical and quantum systems

authors: Kalnins, Ernie G.

subjects: mathematics

abstract: We extend recent work by Tremblay, Turbiner, and Winternitz which analyzes an infinite family of solvable and integrable quantum systems in the plane, indexed by the positive parameter k. Key components of their analysis were to demonstrate that there are closed orbits in the corresponding classical system if k is rational, and for a number of examples there are generating quantum symmetries that are higher order differential operators than two. Indeed they conjectured that for a general class of potentials of this type, quantum constants of higher order should exist. We give credence to this conjecture by showing that for an even more general class of potentials in classicalmechanics, there are higher-order constants of the motion as polynomials in the momenta. Thus these systems are all superintegrable.

text: Superintegrability and higher-order constants for classical and quantum systems We extend recent work by Tremblay, Turbiner, and Winternitz which analyzes an infinite family of solvable and integrable quantum systems in the plane, indexed by the positive parameter k. Key components of their analysis were to demonstrate that there are closed orbits in the corresponding classical system if k is rational, and for a number of examples there are generating quantum symmetries that are higher order differential operators than two. Indeed they conjectured that for a general class of potentials of this type, quantum constants of higher order should exist. We give credence to this conjecture by showing that for an even more general class of potentials in classicalmechanics, there are higher-order constants of the motion as polynomials in the momenta. Thus these systems are all superintegrable.

year: 2011

title: Proximity assurances based on natural and artificial ambient environments

authors: Gurulian, Iakovos

subjects: computer science

abstract: Relay attacks are passive man-in-the-middle attacks that aim to extend the physical distance of devices involved in a transaction beyond their operating environment. In the field of smart cards, distance bounding protocols have been proposed in order to counter relay attacks. For smartphones, meanwhile, the natural ambient environment surrounding the devices has been proposed as a potential Proximity and Relay-Attack Detection (PRAD) mechanism. These proposals, however, are not compliant with industry-imposed constraints that stipulate maximum transaction completion times, e.g. 500 ms for EMV contactless transactions. We evaluated the effectiveness of 17 ambient sensors that are widely-available in modern smartphones as a PRAD method for time-restricted contactless transactions. In our work, both similarity- and machine learning-based analyses demonstrated limited effectiveness of natural ambient sensing as a PRAD mechanism under the operating requirements for proximity and transaction duration specified by EMV and ITSO. To address this, we propose the generation of an Artificial Ambient Environment (AAE) as a robust alternative for an effective PRAD. The use of infrared light as a potential PRAD mechanism is evaluated, and our results indicate a high success rate while remaining compliant with industry requirements.

text: Proximity assurances based on natural and artificial ambient environments Relay attacks are passive man-in-the-middle attacks that aim to extend the physical distance of devices involved in a transaction beyond their operating environment. In the field of smart cards, distance bounding protocols have been proposed in order to counter relay attacks. For smartphones, meanwhile, the natural ambient environment surrounding the devices has been proposed as a potential Proximity and Relay-Attack Detection (PRAD) mechanism. These proposals, however, are not compliant with industry-imposed constraints that stipulate maximum transaction completion times, e.g. 500 ms for EMV contactless transactions. We evaluated the effectiveness of 17 ambient sensors that are widely-available in modern smartphones as a PRAD method for time-restricted contactless transactions. In our work, both similarity- and machine learning-based analyses demonstrated limited effectiveness of natural ambient sensing as a PRAD mechanism under the operating requirements for proximity and transaction duration specified by EMV and ITSO. To address this, we propose the generation of an Artificial Ambient Environment (AAE) as a robust alternative for an effective PRAD. The use of infrared light as a potential PRAD mechanism is evaluated, and our results indicate a high success rate while remaining compliant with industry requirements.

year: 2017

title: 'Entitled to a History': The World of Alice Tawhai's Short Stories and the Maori Literary Tradition

authors: Modlik, Kimberley

subjects: Alice Tawhai

abstract: New Zealand short story writer Alice Tawhai is one of the latest additions to the Maori literary tradition. Her three collections of short stories, Festival of Miracles, Luminous and Dark Jelly, deal with issues not entirely unique to New Zealand – from gang life, to domestic violence, to drug and alcohol abuse – and take as their primary subject an alienated, marginalized and disenfranchised underclass. This means she is likely to be read as speaking solely for the Maori experience.  This thesis will revise this misconception, which in effect ghettoizes or marginalizes Tawhai’s work.

Influential women writers of the Maori literary tradition, such as J. C. Sturm, Patricia Grace and Keri Hulme, have taken a particular interest in the long legacy of colonialism in New Zealand, especially of the impact of that legacy on Maori women. This thesis demonstrates that while Tawhai’s work engages with these familiar notions, her gaze is not limited to these issues. This thesis therefore places Tawhai’s work within that tradition and matrilineal genealogy before going on to show how she moves the paradigm beyond the usual grievances of biculturalism and colonialism, orienting her work instead around the increasingly multicultural experience of contemporary life in New Zealand.

The first section of this thesis will establish a platform for reading Tawhai in regards to her literary legacy and in the context of contemporary thinking, drawing on cultural theorist Stuart Hall and his theory on identity formation and identity politics as well as indigenous writings experts Patrick Evans and Chadwick Allen. This thesis will then move into its second section, which is an analysis of some of the overarching themes that can be found in the short stories of Tawhai’s literary foremothers, Sturm, Grace and Hulme. These include, for example, racism and discrimination, loss of ancestral lands, problems to do with urbanization and family violence.

The third and final section of this thesis will then consider Tawhai’s representation of contemporary experience, taking a particular interest in her portrayals of contemporary multicultural ethnic identities as well as the flexible and provisional nature of gendered and sexual identities today. The final subsection will then analyze her representations of the new family and social structures that may have replaced the traditional family model.

Through a close reading of her short stories and an appreciation of the legacy that she bears, this thesis will show how Tawhai’s work is a larger lens of contemporary New Zealand society as well as a significant addition to the Maori literary tradition.

text: 'Entitled to a History': The World of Alice Tawhai's Short Stories and the Maori Literary Tradition New Zealand short story writer Alice Tawhai is one of the latest additions to the Maori literary tradition. Her three collections of short stories, Festival of Miracles, Luminous and Dark Jelly, deal with issues not entirely unique to New Zealand – from gang life, to domestic violence, to drug and alcohol abuse – and take as their primary subject an alienated, marginalized and disenfranchised underclass. This means she is likely to be read as speaking solely for the Maori experience.  This thesis will revise this misconception, which in effect ghettoizes or marginalizes Tawhai’s work.

Influential women writers of the Maori literary tradition, such as J. C. Sturm, Patricia Grace and Keri Hulme, have taken a particular interest in the long legacy of colonialism in New Zealand, especially of the impact of that legacy on Maori women. This thesis demonstrates that while Tawhai’s work engages with these familiar notions, her gaze is not limited to these issues. This thesis therefore places Tawhai’s work within that tradition and matrilineal genealogy before going on to show how she moves the paradigm beyond the usual grievances of biculturalism and colonialism, orienting her work instead around the increasingly multicultural experience of contemporary life in New Zealand.

The first section of this thesis will establish a platform for reading Tawhai in regards to her literary legacy and in the context of contemporary thinking, drawing on cultural theorist Stuart Hall and his theory on identity formation and identity politics as well as indigenous writings experts Patrick Evans and Chadwick Allen. This thesis will then move into its second section, which is an analysis of some of the overarching themes that can be found in the short stories of Tawhai’s literary foremothers, Sturm, Grace and Hulme. These include, for example, racism and discrimination, loss of ancestral lands, problems to do with urbanization and family violence.

The third and final section of this thesis will then consider Tawhai’s representation of contemporary experience, taking a particular interest in her portrayals of contemporary multicultural ethnic identities as well as the flexible and provisional nature of gendered and sexual identities today. The final subsection will then analyze her representations of the new family and social structures that may have replaced the traditional family model.

Through a close reading of her short stories and an appreciation of the legacy that she bears, this thesis will show how Tawhai’s work is a larger lens of contemporary New Zealand society as well as a significant addition to the Maori literary tradition.

year: 2014