title: Simple harmonic error cancellation in time of flight range imaging

authors: Streeter, Lee

subjects: Three-dimensional image acquisition

abstract: Amplitude modulated continuous wave (AMCW) time of flight (ToF) range imaging provides a full field of distance measurement, but common hardware is implemented with digital technology which leads to unwanted harmonic content, a principle source of error in the distance measurements. Existing strategies for correction of harmonics require auxiliary measurements and amplify noise. A small modification of the data acquisition procedure is described which, intrinsically, is invariant to at least one harmonic. The third harmonic, the main cause of harmonic error, is targeted. Compared to traditional measurements the third harmonic is eliminated with no significant increase in noise variance observed.

text: Simple harmonic error cancellation in time of flight range imaging Amplitude modulated continuous wave (AMCW) time of flight (ToF) range imaging provides a full field of distance measurement, but common hardware is implemented with digital technology which leads to unwanted harmonic content, a principle source of error in the distance measurements. Existing strategies for correction of harmonics require auxiliary measurements and amplify noise. A small modification of the data acquisition procedure is described which, intrinsically, is invariant to at least one harmonic. The third harmonic, the main cause of harmonic error, is targeted. Compared to traditional measurements the third harmonic is eliminated with no significant increase in noise variance observed.

year: 2015

title: To drive, or not to drive: Mode choice in daily commute

authors: Sivasubramaniyam, Rathee Dewi

subjects: Mode choice

abstract: Mode choice for daily commute refers to the process whereby commuters choose a travel mode for their daily trips to work. Despite its ordinary nature, it often involves a series of decisions and consideration of various factors and barriers. More research is needed to understand the various aspects of commuters’ mode choice for daily commute. This thesis comprises three studies that focus on four aspects of mode choice: mode motivating factors, mode commitment, mode decisions, and mode interventions. The thesis aims to present the research gaps that exist in current research related to the four aspects and address them appropriately in the three studies.
The first study sought to identify the motivating factors behind commuters’ mode choices. To address the limitations of investigating only one or two factors and recruiting only a particular type of commuter in a single study, the first study explored the influence of seven psychological factors on five types of commuters’ mode choices. An online survey was distributed to various types of commuters in New Zealand. The results showed that commuters have more than one motivating factor to use their usual modes and some commuters share similar motivating factors.
The first study also aimed to examine how committed commuters are towards their usual modes. To address the limitations of using the categorical measure of modality, the first study involved measuring commuters’ mode commitment using a continuous measure. A 1-week online travel diary was distributed to a subset of the commuters who completed the online questionnaire. The results revealed that the five types of commuters were all committed to their usual modes. However, some of them were more likely to use a combination of more than two modes while others were more likely to use a maximum of two modes for their weekly commutes.
The second study was developed based on the previous findings that all types of commuters were strongly committed towards their usual modes despite having different reasons to use their modes. Thus, the study sought to investigate how commuters decide to use their usual modes for daily commutes by focusing on bounded rationality’s concept of ‘satisficing’ as a decision-making strategy. A sample of New Zealand commuters was invited to complete an online questionnaire. The study found that commuters tend to satisfice when deciding to use their usual modes and commuters with high satisficing tendencies tend to be more positive and satisfied with their regular commutes. 
The third and final study was developed based on assumption that drivers tend to satisfice when deciding to use the car which may explain why current mode-shift interventions have mixed results in terms of their effectiveness. So, the study aimed to test an attitude change intervention known as self-persuasion (i.e., generating arguments to convince oneself) to encourage drivers to reduce their car use. A sample of New Zealand car drivers was invited to complete two online questionnaires and was randomly assigned into one of three conditions (i.e., self-persuasion, direct-persuasion, and control). The study did not find evidence of an effect of self-persuasion on drivers’ car use intentions, behaviours, and attitudes.
Overall, results from the three studies showed the various decisions and factors involved in commuters’ mode choice despite seeming ordinary. The novel approaches used in each study provided new and interesting insights into understanding commuters’ mode choices. The main implication of this thesis is that researchers and policymakers need to take into account these decisions and factors and use various approaches and methods to further understand commuters’ mode choices for their daily commutes and to develop long-lasting mode-shift interventions.

text: To drive, or not to drive: Mode choice in daily commute Mode choice for daily commute refers to the process whereby commuters choose a travel mode for their daily trips to work. Despite its ordinary nature, it often involves a series of decisions and consideration of various factors and barriers. More research is needed to understand the various aspects of commuters’ mode choice for daily commute. This thesis comprises three studies that focus on four aspects of mode choice: mode motivating factors, mode commitment, mode decisions, and mode interventions. The thesis aims to present the research gaps that exist in current research related to the four aspects and address them appropriately in the three studies.
The first study sought to identify the motivating factors behind commuters’ mode choices. To address the limitations of investigating only one or two factors and recruiting only a particular type of commuter in a single study, the first study explored the influence of seven psychological factors on five types of commuters’ mode choices. An online survey was distributed to various types of commuters in New Zealand. The results showed that commuters have more than one motivating factor to use their usual modes and some commuters share similar motivating factors.
The first study also aimed to examine how committed commuters are towards their usual modes. To address the limitations of using the categorical measure of modality, the first study involved measuring commuters’ mode commitment using a continuous measure. A 1-week online travel diary was distributed to a subset of the commuters who completed the online questionnaire. The results revealed that the five types of commuters were all committed to their usual modes. However, some of them were more likely to use a combination of more than two modes while others were more likely to use a maximum of two modes for their weekly commutes.
The second study was developed based on the previous findings that all types of commuters were strongly committed towards their usual modes despite having different reasons to use their modes. Thus, the study sought to investigate how commuters decide to use their usual modes for daily commutes by focusing on bounded rationality’s concept of ‘satisficing’ as a decision-making strategy. A sample of New Zealand commuters was invited to complete an online questionnaire. The study found that commuters tend to satisfice when deciding to use their usual modes and commuters with high satisficing tendencies tend to be more positive and satisfied with their regular commutes. 
The third and final study was developed based on assumption that drivers tend to satisfice when deciding to use the car which may explain why current mode-shift interventions have mixed results in terms of their effectiveness. So, the study aimed to test an attitude change intervention known as self-persuasion (i.e., generating arguments to convince oneself) to encourage drivers to reduce their car use. A sample of New Zealand car drivers was invited to complete two online questionnaires and was randomly assigned into one of three conditions (i.e., self-persuasion, direct-persuasion, and control). The study did not find evidence of an effect of self-persuasion on drivers’ car use intentions, behaviours, and attitudes.
Overall, results from the three studies showed the various decisions and factors involved in commuters’ mode choice despite seeming ordinary. The novel approaches used in each study provided new and interesting insights into understanding commuters’ mode choices. The main implication of this thesis is that researchers and policymakers need to take into account these decisions and factors and use various approaches and methods to further understand commuters’ mode choices for their daily commutes and to develop long-lasting mode-shift interventions.

year: 2021

title: Beyond structuralism: Exploring a semantic based approach for describing the Māori language in grammar books and textbooks for pedagogical purposes

authors: Taiapa, Michael William

subjects: Māori

abstract: Since the 1950s, the advancements and developments in English language studies has had a profound impact on its description that has made it less syntactically driven and more communicatively oriented. This has the potential to influence language description moving it from a purely structurally focused orientation to a more semantically focused one that could influence pedagogic outcomes in more meaningful and useful ways. Nevertheless, in the case of the Māori language, its description has largely focused on structure linguistics that was prevalent in the 19th and early 20th centuries. There has been very little focus on a semantic description and this, in turn, is reflected in grammar books and textbooks on te reo. This thesis set out to explore a semantic approach to describe te reo and to rethink how this type of description may be realized and included in the design of grammar books and textbooks for the teaching and learning of te reo in the broader field of second language pedagogy and acquisition. The thesis also includes a practical component in which a small sample of Māori language teachers were interviewed to determine how linguistic and/ or semantic approaches to describe te reo may have or have impacted on their own beliefs, attitudes, and teaching practices (See, Chapter 7). Thus, it is argued here that research-based studies, advancements, and developments in language descriptions over the past five decades (See, for example, Council of Europe, 1949; Fillmore, 1967; Longacre, 1968; & Crombie, 1985b) should play central roles in the design of a semantic based description of the Māori language from which a linguistic based description can significantly benefit.

text: Beyond structuralism: Exploring a semantic based approach for describing the Māori language in grammar books and textbooks for pedagogical purposes Since the 1950s, the advancements and developments in English language studies has had a profound impact on its description that has made it less syntactically driven and more communicatively oriented. This has the potential to influence language description moving it from a purely structurally focused orientation to a more semantically focused one that could influence pedagogic outcomes in more meaningful and useful ways. Nevertheless, in the case of the Māori language, its description has largely focused on structure linguistics that was prevalent in the 19th and early 20th centuries. There has been very little focus on a semantic description and this, in turn, is reflected in grammar books and textbooks on te reo. This thesis set out to explore a semantic approach to describe te reo and to rethink how this type of description may be realized and included in the design of grammar books and textbooks for the teaching and learning of te reo in the broader field of second language pedagogy and acquisition. The thesis also includes a practical component in which a small sample of Māori language teachers were interviewed to determine how linguistic and/ or semantic approaches to describe te reo may have or have impacted on their own beliefs, attitudes, and teaching practices (See, Chapter 7). Thus, it is argued here that research-based studies, advancements, and developments in language descriptions over the past five decades (See, for example, Council of Europe, 1949; Fillmore, 1967; Longacre, 1968; & Crombie, 1985b) should play central roles in the design of a semantic based description of the Māori language from which a linguistic based description can significantly benefit.

year: 2023