title: Doppler velocimetry lidar with amplified reference beam storage loop

authors: Shen, Jyi-Lai

abstract: Wind shear and clear air turbulence are phenomena in which wind speeds can change rapidly presenting a threat to aircraft and their passengers. Lidar is a proven technique for wind speed measurement but remains a research tool only and is not yet commercially viable as an early warning system. This is mainly due to the expense and bulk of the single frequency injection locked lasers required for long-range coherent measurements. 

A different design philosophy for a pulsed Doppler lidar system has recently been presented in the literature, where the reference beam pulse is stored in a fibre optic storage loop. Each successive reference pulse has travelled a distance equivalent to the measurement beam’s path length. This approach reduces the coherence requirements and allows the use of cheaper, smaller, and lower coherence sources. However, a major problem of this system is that the energy of the stored pulses decays exponentially. 

This thesis introduces a new and improved reference pulse storage loop, which includes an erbium doped fibre amplifier to compensate for the decay of the reference signal. Details of the design are presented. The original storage loop concept is transferred to the fibre optics telecommunication wavelength range of 1.55μm. The noise and gain of the system is characterized. Special attention is paid to avoiding laser oscillation while maintaining sufficient gain. The components, like isolators, filters, and polarisation controllers, required to achieve satisfactory operation are presented. Electronic and software techniques based on phase lock loop and wavelet transformation are included in the overall system design to reduce noise. The experiments prove that the amplitude of 16 stored pulses remains constant to within 10% fluctuation.

To prove the validity of the concept the velocity of a rotating mirror is measured at various measurement distances of 0 to 583 m that coincide with the 16 reference pulses. The experiments show successful optical mixing between the stored amplified reference and the delayed measurement beams. In the range 1 to 10 m/s the velocity can be determined to better than ±0.14 m/s (standard deviation). Software simulations of the system indicate that with improved equipment measurements should be possible for up to 70 stored pulses, which correspond to a measurement distance of 2,550 m.

The results obtained illustrate that the amplified reference beam storage loop is a viable concept for Doppler lidar velocimetry.

text: Doppler velocimetry lidar with amplified reference beam storage loop Wind shear and clear air turbulence are phenomena in which wind speeds can change rapidly presenting a threat to aircraft and their passengers. Lidar is a proven technique for wind speed measurement but remains a research tool only and is not yet commercially viable as an early warning system. This is mainly due to the expense and bulk of the single frequency injection locked lasers required for long-range coherent measurements. 

A different design philosophy for a pulsed Doppler lidar system has recently been presented in the literature, where the reference beam pulse is stored in a fibre optic storage loop. Each successive reference pulse has travelled a distance equivalent to the measurement beam’s path length. This approach reduces the coherence requirements and allows the use of cheaper, smaller, and lower coherence sources. However, a major problem of this system is that the energy of the stored pulses decays exponentially. 

This thesis introduces a new and improved reference pulse storage loop, which includes an erbium doped fibre amplifier to compensate for the decay of the reference signal. Details of the design are presented. The original storage loop concept is transferred to the fibre optics telecommunication wavelength range of 1.55μm. The noise and gain of the system is characterized. Special attention is paid to avoiding laser oscillation while maintaining sufficient gain. The components, like isolators, filters, and polarisation controllers, required to achieve satisfactory operation are presented. Electronic and software techniques based on phase lock loop and wavelet transformation are included in the overall system design to reduce noise. The experiments prove that the amplitude of 16 stored pulses remains constant to within 10% fluctuation.

To prove the validity of the concept the velocity of a rotating mirror is measured at various measurement distances of 0 to 583 m that coincide with the 16 reference pulses. The experiments show successful optical mixing between the stored amplified reference and the delayed measurement beams. In the range 1 to 10 m/s the velocity can be determined to better than ±0.14 m/s (standard deviation). Software simulations of the system indicate that with improved equipment measurements should be possible for up to 70 stored pulses, which correspond to a measurement distance of 2,550 m.

The results obtained illustrate that the amplified reference beam storage loop is a viable concept for Doppler lidar velocimetry.

year: 2003

title: Using SmartQuit®, an acceptance and commitment therapy smartphone application, to reduce smoking intake.

authors: Singh, Satvir

subjects: Acceptance and Commitment Therapy

abstract: Objective: SmartQuit® is a smartphone application (app) for smoking cessation based on Acceptance and Commitment Therapy, a behavioural therapy that encourages individuals to accept internal experiences, such as cravings to smoke, without acting on those experiences or urges. We used a single-subject (A-B-A) design with 10 participants to examine whether SmartQuit® use would reduce cigarette intake in a New Zealand sample. 
Methods: 10 smokers tallied their own cravings experienced and cigarettes smoked then sent those tallies to the first author every day until we observed stable patterns (Phase A1). We then gave the participants individual access to the SmartQuit® app (Phase B). When they advised that they had ceased using the app, they again recorded daily cravings and cigarettes smoked for a minimum of three days (Phase A2). We also collected follow-up smoking and craving data at 1, 2 and up to 13 months after completion of Phase A2. 
Results: Using SmartQuit® reduced our participants' daily cigarette intake significantly in the short-term and three individuals remained smoke-free up to 13 months later. Cravings to smoke did not differ significantly across Phases A1, B and A2, but graphical analysis showed a trend for decreasing cravings. 
Conclusion: Our results suggest that SmartQuit® provides another readily accessible intervention to help people stop smoking and is suited for use with a New Zealand population.

text: Using SmartQuit®, an acceptance and commitment therapy smartphone application, to reduce smoking intake. Objective: SmartQuit® is a smartphone application (app) for smoking cessation based on Acceptance and Commitment Therapy, a behavioural therapy that encourages individuals to accept internal experiences, such as cravings to smoke, without acting on those experiences or urges. We used a single-subject (A-B-A) design with 10 participants to examine whether SmartQuit® use would reduce cigarette intake in a New Zealand sample. 
Methods: 10 smokers tallied their own cravings experienced and cigarettes smoked then sent those tallies to the first author every day until we observed stable patterns (Phase A1). We then gave the participants individual access to the SmartQuit® app (Phase B). When they advised that they had ceased using the app, they again recorded daily cravings and cigarettes smoked for a minimum of three days (Phase A2). We also collected follow-up smoking and craving data at 1, 2 and up to 13 months after completion of Phase A2. 
Results: Using SmartQuit® reduced our participants' daily cigarette intake significantly in the short-term and three individuals remained smoke-free up to 13 months later. Cravings to smoke did not differ significantly across Phases A1, B and A2, but graphical analysis showed a trend for decreasing cravings. 
Conclusion: Our results suggest that SmartQuit® provides another readily accessible intervention to help people stop smoking and is suited for use with a New Zealand population.

year: 2017

title: He pakiriha

authors: Temara, Pou

subjects: Tikanga

abstract: Kua tae ki te wā hai kōrero i ētahi tikanga marae, ētahi tikanga kawa e kawa ana ki tā te mātanga titiro. Tērā ētahi tikanga e whakamahia ana e ngā kaumātua o nāianei e uru atu ana ki te pae o rorirori, ka mutu, e ai ki tā ngā kaumātua nei, ko te mutunga mai o te tika ā rātau i whakatau ai. Nā hei whakarāpopoto i te whakaaro whānui, i ētahi wā kāore ko te mea e tika ana ki ō tātau whakaaro te huarahi pai. Ko tā te tikanga he kimi i te huarahi e tika ana, kia kore ai e whara ngā whakaaro o te tangata. Ko te tikanga ehara i te mea i whakairotia ki te kōhatu, engari e taea ana te neke i ngā pae o te tikanga kia pai ai te whakahaere a te tangata i āna mahi, kia tau ai te rangimārie, kia mau tonu ai te mana o te tangata. E whakapae ana ahau e kūmea ana e ētahi kaumātua ētahi tikanga kia hāngai ki tā rātau i whakaaro ai kai te tika, kai te hē rānei. Mā ētahi tauira e mārama ai te kaipānui ki te kaupapa me te whakaaro o te kaituhi.

text: He pakiriha Kua tae ki te wā hai kōrero i ētahi tikanga marae, ētahi tikanga kawa e kawa ana ki tā te mātanga titiro. Tērā ētahi tikanga e whakamahia ana e ngā kaumātua o nāianei e uru atu ana ki te pae o rorirori, ka mutu, e ai ki tā ngā kaumātua nei, ko te mutunga mai o te tika ā rātau i whakatau ai. Nā hei whakarāpopoto i te whakaaro whānui, i ētahi wā kāore ko te mea e tika ana ki ō tātau whakaaro te huarahi pai. Ko tā te tikanga he kimi i te huarahi e tika ana, kia kore ai e whara ngā whakaaro o te tangata. Ko te tikanga ehara i te mea i whakairotia ki te kōhatu, engari e taea ana te neke i ngā pae o te tikanga kia pai ai te whakahaere a te tangata i āna mahi, kia tau ai te rangimārie, kia mau tonu ai te mana o te tangata. E whakapae ana ahau e kūmea ana e ētahi kaumātua ētahi tikanga kia hāngai ki tā rātau i whakaaro ai kai te tika, kai te hē rānei. Mā ētahi tauira e mārama ai te kaipānui ki te kaupapa me te whakaaro o te kaituhi.

year: 2017