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Item Solvent neurotoxicity in vehicle collision repair workers : a thesis by publications presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Public Health, Massey University, Wellington, New Zealand(Massey University, 2018) Keer, Samuel JohnPrevious studies have shown that vehicle collision repair workers may be at risk of solvent-induced symptoms of neurotoxicity. Changes in industry practices have likely resulted in reduced exposure, but little research has been conducted to assess whether this has reduced the risk of neurotoxicity. This thesis describes a series of studies, which aimed to assess: i) contemporary airborne solvent exposures in collision repair workers; ii) the determinants of airborne solvent exposures; iii) the prevalence of self-reported symptoms of neurotoxicity and objectively measured neuropsychological performance, compared to an unexposed reference group; iv) dose-response associations; and v) the effect of personal protective equipment (PPE) and good workplace hygiene on symptom prevalence. In total, 370 vehicle collision repair and 211 construction workers (reference group) were recruited. Personal airborne solvent exposure was assessed in 85 collision repair workers, and information on demographics, work practices and symptoms was collected by questionnaire. A sub-group of 47 collision repair and 51 reference workers also completed a battery of neuropsychological tests. Full-shift, airborne exposures were well below New Zealand and international occupational exposure limits (range, 0.04 – 16.5 ppm). Job title was the strongest predictor of exposure, and non-spraying tasks (e.g. mixing paint and cleaning equipment) were associated with higher exposures than spray painting itself. Collision repair workers reported significantly more symptoms of neurotoxicity than the reference group, with odds ratios (ORs) of 2.0, 95% CI 1.3-3.3; 2.4, 1.2-4.8; and 6.4, 1.8-23.0, for reporting ≥5, ≥10 and ≥15 symptoms, respectively. They also performed more poorly on neuropsychological tests, particularly those that measure attention/concentration and motor speed/dexterity (e.g. reference vs. collision repair group score on the RBANS total attention scale, -9.5, 95% CI, -15.9, -2.8). Consistent use of PPE (particularly gloves) and good workplace hygiene practices were strongly protective against symptoms, with reductions in risk of up to 90% for those who most consistently wore PPE. In conclusion, despite relatively low airborne exposure levels, collision repair workers continue to be at risk of solvent-induced neurotoxicity. These findings provide a strong evidence-base for the development and implementation of intervention programmes to reduce solvent exposures and associated morbidity in this population.Item What do YOU think about this car? : perception and meaning of automotive design in New Zealand and Taiwan : a thesis submitted for the degree of Master of Design at College of Creative Arts, Massey University, Wellington, New Zealand(Massey University, 2008) Wang, Wen-Chun (Diana)This investigation examines the relationship between perception and meaning on automotive exterior designs in New Zealand and Taiwan. The Visual Product Experience framework [Warell, 2007] categorises perception and meaning Impression, Recognition, Appreciation, Association and Comprehension. This study uses the VPE framework to examine the perception and meaning of the specific car models from BMW and Lexus in two markets. It did so through the collection of qualitative data from questionnaires conducted through a semi-structured interview, with a total of 60 participants in automotive-related events in both New Zealand and Taiwan. The background of this project was established through the secondary research that explored a wide range of topics including the theoretical knowledge review, characteristics of the markets and design philosophies of the car brands. Through these researches, the differences in the market characteristics and design focuses of the brand BMW and Lexus are verified. The findings indicate that the BMW 320i has strong visual impression on consumers in both markets with regard to aesthetics and identity. This strong visual impression was attributed by the overall coherent visual composition of the 320i. The design features of the Lexus IS250 were more recognised by Taiwan consumers than New Zealand consumers. The visual features designed to express and describe on both cars were perceived consistently by consumers in both market. Interestingly, the Lexus Arrowhead motif was not recognised as an overall visual appearance, but as individual details. However, the grille of the Lexus as not consistently indicated as a signifier of the Lexus brand. This was in contrast to the BMW 'Kidney Grille', which was consistently recognised as a BMW signifier. The results of this study were consistent with the findings of the literature review. This is evident because the participants from Taiwan strongly associate the cars with their values in society. Between the two markets, differences in interpretation of the design features is apparent, Taiwan consumers appreciates smaller details more than New Zealand consumers. The VPE framework is proven to be a highly comprehensive model in this research project. This is because it allows categorisations and hence an inclusive understanding on the design intents and analysis on the 320i/IS250 both in the secondary and primary research design and analysis.Item Real-time adaptive noise cancellation for automatic speech recognition in a car environment : a thesis presented in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Computer Engineering at Massey University, School of Engineering and Advanced Technology, Auckland, New Zealand(Massey University, 2008) Qi, ZimingThis research is mainly concerned with a robust method for improving the performance of a real-time speech enhancement and noise cancellation for Automatic Speech Recognition (ASR) in a real-time environment. Therefore, the thesis titled, “Real-time adaptive beamformer for Automatic speech Recognition in a car environment” presents an application technique of a beamforming method and Automatic Speech Recognition (ASR) method. In this thesis, a novel solution is presented to the question as below, namely: How can the driver’s voice control the car using ASR? The solution in this thesis is an ASR using a hybrid system with acoustic beamforming Voice Activity Detector (VAD) and an Adaptive Wiener Filter. The beamforming approach is based on a fundamental theory of normalized least-mean squares (NLMS) to improve Signal to Noise Ratio (SNR). The microphone has been implemented with a Voice Activity Detector (VAD) which uses time-delay estimation together with magnitude-squared coherence (MSC). An experiment clearly shows the ability of the composite system to reduce noise outside of a defined active zone. In real-time environments a speech recognition system in a car has to receive the driver’s voice only whilst suppressing background noise e.g. voice from radio. Therefore, this research presents a hybrid real-time adaptive filter which operates within a geometrical zone defined around the head of the desired speaker. Any sound outside of this zone is considered to be noise and suppressed. As this defined geometrical zone is small, it is assumed that only driver's speech is incoming from this zone. The technique uses three microphones to define a geometric based voice-activity detector (VAD) to cancel the unwanted speech coming from outside of the zone. In the case of a sole unwanted speech incoming from outside of a desired zone, this speech is muted at the output of the hybrid noise canceller. In case of an unwanted speech and a desired speech are incoming at the same time, the proposed VAD fails to identify the unwanted speech or desired speech. In such a situation an adaptive Wiener filter is switched on for noise reduction, where the SNR is improved by as much as 28dB. In order to identify the signal quality of the filtered signal from Wiener filter, a template matching speech recognition system that uses a Wiener filter is designed for testing. In this thesis, a commercial speech recognition system is also applied to test the proposed beamforming based noise cancellation and the adaptive Wiener filter.