title: Application of lidar techniques to time-of-flight range imaging

authors: Whyte, Refael

subjects: Science & Technology

abstract: Amplitude modulated continuous wave (AMCW) time-of flight (ToF) range imaging cameras measure distance by illuminating the scene with amplitude modulated light and measuring the phase difference between the transmitted and reflected modulation envelope. This method of optical range measurement suffers from errors caused by multiple propagation paths, motion, phase wrapping and non-ideal amplitude modulation. In this paper a ToF camera is modified to operate in modes analogous to continuous wave (CW) and stepped frequency continuous wave (SFCW) lidar. In CW operation the velocity of objects can be measured. CW measurement of velocity was linear with true velocity (R² = 0.9969). Qualitative analysis of a complex scene confirms that range measured by SFCW is resilient to errors caused by multiple propagation paths, phase wrapping and non-ideal amplitude modulation which plague AMCW operation. In viewing a complicated scene through a translucent sheet, quantitative comparison of AMCW with SFCW demonstrated a reduction in the median error from −1.3 m to −0.06 m with inter-quartile range of error reduced from 4.0 m to 0.18 m.

text: Application of lidar techniques to time-of-flight range imaging Amplitude modulated continuous wave (AMCW) time-of flight (ToF) range imaging cameras measure distance by illuminating the scene with amplitude modulated light and measuring the phase difference between the transmitted and reflected modulation envelope. This method of optical range measurement suffers from errors caused by multiple propagation paths, motion, phase wrapping and non-ideal amplitude modulation. In this paper a ToF camera is modified to operate in modes analogous to continuous wave (CW) and stepped frequency continuous wave (SFCW) lidar. In CW operation the velocity of objects can be measured. CW measurement of velocity was linear with true velocity (R² = 0.9969). Qualitative analysis of a complex scene confirms that range measured by SFCW is resilient to errors caused by multiple propagation paths, phase wrapping and non-ideal amplitude modulation which plague AMCW operation. In viewing a complicated scene through a translucent sheet, quantitative comparison of AMCW with SFCW demonstrated a reduction in the median error from −1.3 m to −0.06 m with inter-quartile range of error reduced from 4.0 m to 0.18 m.

year: 2015

title: Revealing the effects of ill global eco-financial systems and their capsules

authors: Mengesha, Lula G.

subjects: global financial crisis

abstract: This paper examines the origins of the global crisis, the impact of the crisis and the different capsules taken to address the crisis. Using daily data from mid-July 2002 to mid-July 2012 for five groups of economies, our estimation is based on BEKK diagonal GARCH. We augmented two dummy variables to represent the U.S. financial crisis and the debt crisis of Greece. We find that the U.S crisis has insignificant impact on the mean returns of all the economies except the African economies. The U.S. financial crisis, however, has positive and significant impact on the stock volatilities of all the groups except the African economies. The debt crisis of Greece, on the other hand, has negative and significant impact on the mean returns of the European and Latin American economies. Its impact on the stock volatilities, however, is positive and significant in all the economies except the African economies. In examining the origins of the crisis, we identify that excessive reliance of the U.S. economy on the credit system and on the stock market together with historic negligence of the production sector and inadequate regulation are some causative factors.

text: Revealing the effects of ill global eco-financial systems and their capsules This paper examines the origins of the global crisis, the impact of the crisis and the different capsules taken to address the crisis. Using daily data from mid-July 2002 to mid-July 2012 for five groups of economies, our estimation is based on BEKK diagonal GARCH. We augmented two dummy variables to represent the U.S. financial crisis and the debt crisis of Greece. We find that the U.S crisis has insignificant impact on the mean returns of all the economies except the African economies. The U.S. financial crisis, however, has positive and significant impact on the stock volatilities of all the groups except the African economies. The debt crisis of Greece, on the other hand, has negative and significant impact on the mean returns of the European and Latin American economies. Its impact on the stock volatilities, however, is positive and significant in all the economies except the African economies. In examining the origins of the crisis, we identify that excessive reliance of the U.S. economy on the credit system and on the stock market together with historic negligence of the production sector and inadequate regulation are some causative factors.

year: 2012-12

title: Exploring the experiences of young Māori mothers

authors: Shepherd, Cindy-Joe Theresa Aroha

subjects: Young Māori mothers

abstract: This thesis explores the lived experiences of three young Māori mothers (aged 16 
years old) in Aotearoa, New Zealand, focusing on their strengths, challenges, and resilience. 
By employing a Kaupapa Māori methodological framework, the research aims to reframe 
narratives about young Māori mothers towards a strengths-based perspective, advocating for 
protection and nurturing Māori whakapapa. Using qualitative methods, the study explores the 
pūrākau (stories) of three young Māori mothers attending a teen parent unit in Waikato. 
The study highlights how, by living within both individualistic and collective realms, 
these young mothers actively challenge stigma, assert their worth, and develop unique 
underlying strengths. The findings, structured around emergent themes from their collective 
experiences, reveal a dichotomy: these young mothers must navigate the individualistic 
pressures and high expectations of motherhood while also drawing strength from collective 
responsibilities upheld within their whānau and supportive community services. Despite 
facing significant societal stigma and systemic barriers, the mothers demonstrate immense 
strength. Their resilience is grounded in whānau connections, proactive self-care, and 
engagement with taiao, wairua, and tino rangatiratanga—processes that also support 
intergenerational healing. 
This research underscores the importance of culturally responsive support systems 
that honour Indigenous knowledge and collective well-being. It offers insights for reorienting 
policy and practice to empower young Māori mothers, recognising their tino rangatiratanga 
and transformative agency by embracing their multifaceted realities.

text: Exploring the experiences of young Māori mothers This thesis explores the lived experiences of three young Māori mothers (aged 16 
years old) in Aotearoa, New Zealand, focusing on their strengths, challenges, and resilience. 
By employing a Kaupapa Māori methodological framework, the research aims to reframe 
narratives about young Māori mothers towards a strengths-based perspective, advocating for 
protection and nurturing Māori whakapapa. Using qualitative methods, the study explores the 
pūrākau (stories) of three young Māori mothers attending a teen parent unit in Waikato. 
The study highlights how, by living within both individualistic and collective realms, 
these young mothers actively challenge stigma, assert their worth, and develop unique 
underlying strengths. The findings, structured around emergent themes from their collective 
experiences, reveal a dichotomy: these young mothers must navigate the individualistic 
pressures and high expectations of motherhood while also drawing strength from collective 
responsibilities upheld within their whānau and supportive community services. Despite 
facing significant societal stigma and systemic barriers, the mothers demonstrate immense 
strength. Their resilience is grounded in whānau connections, proactive self-care, and 
engagement with taiao, wairua, and tino rangatiratanga—processes that also support 
intergenerational healing. 
This research underscores the importance of culturally responsive support systems 
that honour Indigenous knowledge and collective well-being. It offers insights for reorienting 
policy and practice to empower young Māori mothers, recognising their tino rangatiratanga 
and transformative agency by embracing their multifaceted realities.

year: 2024-06-23