Science

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Now showing 1 - 6 of 6
  • (2023) Ma, Mingyou
    Thesis
    With the rapid growth of e-commerce, the surging freight traffic is imposing unprecedented pressure on urban transport systems. To mitigate negative impacts of urban freight traffic, the integrated public transport system, i.e., urban co-modality, has been proposed to utilize the existing urban passenger transport system to also carry freight during off-peak hours. Despite the benefits, the co-modal system might reduce public transport reliability and demand due to freight loading/unloading and transshipment operations. This thesis focuses on understanding and modelling the emerging integrated co-modal system for passengers and freight, and investigating and managing its system-wide impacts. This thesis first uses the smart transit card data to understand the travel behaviour of public transport users, and quantify the impact of public transport reliability on users’ day-to-day travel choices. We find that public transport users tend to reserve safety margin for the unforeseen service unreliability. Besides, we also find that there was under-utilized capacity in transit services operating during off-peak hours, which indicates the potential for transporting freight in the public transport system. With the understanding of service-reliability-based travel choices, this thesis then models the mixed freight-passenger cross-type flow and strategic interactions among operators and users in a standalone co-modal system. We first construct a fundamental game-theoretical model based on the essential characteristics of the co-modal system, such as negative impacts of freight on passenger demand. In the fundamental model, we examine the strategic interaction between a transit operator and a freight operator. We show that introducing the co-modality has the potential to generate Pareto-improving outcomes for the operators. This model is extended by considering the endogenous interactions among freight customers, passengers, freight and transit operators. We find that the co-modal system may enhance levels of services for both passengers and freight customers. Building upon these, this thesis further explores the impact of the co-modal system on the freight transport market with outsourcing arrangements. The non-cooperative and cooperative games among a freight carrier, a freight integrator, and a transit operator are modelled, and the co-modal system performance is quantified.

  • (2023) Wilson, David
    Thesis
    This thesis investigates issues important to the aviation industry, quantifying the likelihood of flights arriving in unsafe or inefficient circumstances from inaccurate airport weather forecasts (TAF, TTF and TAF3). Key issues include investigating: the likelihood of recurrence for an accident which occurred at Norfolk Island in 2009; the likelihood of adverse situations during aeromedical flights arriving at Australian remote islands and capital city aerodromes; and the potential impact of TAF3 use for major airport arrivals. Unsafe situations, or ‘misses’, where flights arrive during unplanned unsuitable weather, may result in landings below safe limits, or aircraft safety incidents. Inefficient situations, or ‘false alarms’, where pilots have planned for adverse weather that does not eventuate, have economic and environmental implications due to extra unnecessary fuel being carried. No suitable existing methodology was identified to achieve the research objectives, requiring development of a new utility-based weather forecast verification model. This model compares simulated decisions of historical aerodrome weather forecast use with actual meteorological conditions. The key element of the model is the measurement of likelihood of unsafe or inefficient situations based on the time prior to arrival (‘time-offset’) that forecasts were available to pilots. Results are calculated using a computer-based implementation of this model. The odds of a ‘miss’ at Norfolk Island were found to be 1 in 859 when simulating the flight plan that was used in the 2009 accident. These odds were predicted to be 1.8 times lower if the ‘time-offset’ between forecast promulgation and planned arrival time was reduced from 5 to 2 hours, the latter time being at the point of last safe diversion. For aeromedical flights to Australian remote islands and to the five busiest capital city aerodromes, strong linear relationships between ‘miss’ likelihood and ‘time-offsets’ between 0 and 12 hours were identified at all locations except for Melbourne and Sydney, with strong second-order relationships identified for ‘false alarms’. ‘False alarms’ are predicted to be considerably more likely at remote islands compared to capital cities, although there was no discernible trend between these groups for ‘misses’. When using all TAF3 information for planning, the replacement of TTF with TAF3 forecasts at Australia’s five busiest major aerodromes is predicted to reduce ‘miss’ arrivals by 34% (enhancing safety), and increase ‘false alarm’ arrivals (when flight have excessive fuel) by 91%. TAF3 PROB segments are predicted to contribute to at least 80% of this change due to the proportion of time these had an operational effect.

  • (2023) Dunn, Matthew
    Thesis
    Remotely piloted aircraft systems (RPAS) offer new possibilities to a growing civilian field. However, unlike pilots of conventionally piloted aircraft, the remote pilot operates in a sensory deprived environment. A reduction in available sensory cues present unique human factors challenges, hence the aim of the present study was to understand the impact of real-time auditory feedback from the RPA on operator performance. Experiment 1 tested conventional pilots manually flying a small multi-rotor RPA under two visual operating conditions. Experiment 2 introduced a non-pilot participant group in an automated configuration. Experiment 3 retained the methodology of the second, but presented an adaptable auditory feedback component, with incremental volumes above and below a comfortable sound level. Key findings revealed transitional instances of auditory feedback being perceived as either sound (i.e., useful information, and/or arousing) or noise (i.e., sound that is unwanted), with results broadly aligned with predicted values associated with behavioural models of performance such as the Maximal Adaptability Model. In addition, no statistical significant differences in task performance (automated flight conditions) between the pilot and non-pilot participants were evident. Together, these findings suggest the ability to include or remove the availability of sensory cueing for remote pilots should be dependent on the stage of flight and associated workload. In addition, they raise questions about the restrictions imposed on who is permitted to operate an RPA. Practically, this gives credence to the inclusion of adaptable sensory cueing in future systems. Furthermore, consideration should be given to licensing operators without conventional flying experience for more complex, automated RPAS operations.

  • (2023) Tyagi, Sarika
    Thesis
    The use of newer and advanced technologies such as Self-Service Technologies (SSTs), is constantly evolving for various services at airports to enhance the passenger experience, level of satisfaction and overall productivity. However, it is important to examine such developments to ascertain to what extent they fulfil the requirements of the airport operations such as departure and arrival operations from the passenger perspective. Therefore, this study assesses the passenger perspectives toward the implemented SSTs such as the Self-Service Kiosk (SSK) and online/mobile for the departure operation’s passenger check-in process at Sydney airport. To achieve the objectives of this study, three different sub-studies were conducted. In study 1, an online survey was conducted, and the collected data were analysed using Chi-square and T-tests to investigate passenger perspectives toward SST use. Chi-square results showed that the use of SSTs was not associated with passengers' social and demographic characteristics such as gender, flying experience and age, nor with situational factors, such as the presence of staff members at self-service. This was confirmed by T-test results which showed no significant difference between the average use of SSTs by male and female passengers, frequency of travel or whether passengers received staff assistance at self-service. In addition, situational factors such as better signage to locate the service, reduced number of customers waiting for service, less waiting time, and less processing time positively impacted SST usage. Furthermore, the results of study 1 also showed that passengers travelling frequently experienced less processing time at SSKs, and passengers intended to use SSK at the airport arrived closer to the flight departure time. In study 2, the CAST software (terminal simulation) was used to examine the passenger processing time at SSKs, the number of passengers using SSKs, and passenger arrival times at the terminal. The results were used to examine the impact of these factors on the check-in process (i.e., waiting time). The simulated scenarios reflected the positive impact of SSK use on the waiting time. For instance, the replacement of two traditional check-in desks with two SSKs for the check-in process reduced the waiting time from 18.7 minutes to 6.2 minutes for passengers using these SSKs, and this was further reduced to 1.1 minutes with four SSKs. A survey conducted in study 3 included questions where passengers were asked to share their experience after using SSK at the airport. The variables corresponding to these questions were reduced to a manageable and interpretable set of factors using the factor analysis methodology. The results identified five factors, including beneficial, accessible, inconvenient, insecure and ineffective, attributing passenger perspectives toward the SSKs. The findings can be used to improve SST use for seamless passenger processing at the airport and passenger experience by focusing on the passenger characteristics which have an association with SST use. Furthermore, the evaluation of passenger arrival time and the use of check-in mode on arriving at the airport can help with the correct allocation of adequate numbers of traditional check-in desks and SSKs, which consequently will save costs and reduce waiting time for passengers. In addition, the identified five factors could be used in future studies and surveys to measure the passenger experience of SSTs.

  • (2023) Li, Xinming
    Thesis
    As both data and computational access have grown, disaggregate modelling has been gradually growing its popularity in the domain of travel demand modelling and tourism decision modelling. One of the major benefits of disaggregate model is that the actual behaviour of individuals can be observed and captured when a model is developed in a bottom-up way, as opposed to a top-down fashion. In addition, to this behavioural characteristic, disaggregate models are more policy sensitive as the impact of a small change in the market on people’s decisions can be observed and estimated. Tourism decision-making process is commonly perceived as a multifaceted and complex problem. Tourists are usually required to make decisions on a series of behavioural choices including destination, time of travel, transport modes, travel party, Length of stay (LOS) and expenditure, etc. Many tourism researchers demonstrated that these decisions are interrelated in nature. Such interrelations indicate that an intended tourism policy or marketing strategy would have its unintended consequences. Therefore, the objective of this thesis is to explore, introduce and develop model frameworks with highly disaggregate system of models for jointly simulating multiple attributes activities. In the first core chapter (CHAPTER 3), the aim is to develop a hazard-based discrete-continuous model for understanding tourists’ decision making on time of year for travel (seasonal variation) and associated length of stay (LOS) with regard to different travel modes. The model results, which is tested with data from select years between 1999-2018, including years of significant exogenous shocks, show mixed evidence of stability and changes in the parameters. Building on this evidence, this chapter concludes with underlying temporal choice behaviours of tourists that may be of relevance during- and post-COVID19 environment. In the second core chapter (CHAPTER 4), the aim is to extend the previous work to incorporate three tourism decisions by endogenizing transport modes, where a fully nested Archimedean copula structure is adopted for modelling practice. To illustrate its application, the modelling results are used to build a simulated COVID-19 pandemic scenario according to the social distancing restrictions within New South Wales, Australia, and a three-dimensional elasticity analysis for trip destinations is performed. The findings suggest the model provides nuanced insights into simulating tourist behaviours and appraisal of transport policies aimed at tourism recovery or/and development. In the third chapter (CHAPTER 5), the aim is to calibrate a trivariate Archimedean copulas for activity participation, transport modes and accommodation selection while accounting for the correlation between the unobserved heterogeneity of each individual model. Based on the findings of this chapter, we identify the major participants of Australia’s aboriginal activities are senior groups. However, in order to inherit and develop Australia’s indigenous cultural tradition, potential collaborations can be built up among stakeholders such as government, schools/universities, travel agents, bus/coach rental corporates and hotels. Overall, this thesis advances the study and applications of joint models in the domain of multiple tourism modelling. Results of this work provide valuable insights into the interrelations of different tourism decisions, understanding of which can greatly assist in developing more tailored and oriented policies or marketing strategies towards tourists.

  • (2023) Zhou, Hang
    Thesis
    Noise and workload are both stressors. Stressors are known to affect cognitive performance. While the effect of workload on cognition is widely known, the effect of noise is less understood. Broadband noise at moderate levels (<85 dBA) is typical in many workplaces. Dynamic decision-making (DDM), a complex cognitive task, is required in many workplace settings where moderate broadband noise is present. Understanding how stressors such as noise affect DDM is essential, especially in safety critical professions such as aviation and emergency response. Therefore, the aim of the present research was to understand the effect of moderate broadband noise on DDM and the moderators that can influence the extent of that effect. Study 1, the first of the three studies, was a systematic review for the effect of moderate broadband noise on cognition such as reaction time, attention, short-term memory, long-term memory and high(er)-order cognitive tasks such as DDM. The findings showed that no previous studies investigated the effect of moderate broadband noise on DDM. Study 2, the first of two empirical studies examined the link between noise at 75 dBA, sex, workload, and session on DDM (performance and learning). Study 3 introduced the moderator of financial incentive and additional instructions. The results indicated females’ performance in DDM was affected by noise at low workload, but not high workload. Males were overall unaffected by noise regardless of the workload level. In terms of learning, noise initially impaired females’ performance, however this was overcome in Day 2. The added instruction had the same positive effect on learning performance, as it neutralised the noise effect. Monetary incentives did not moderate the noise stressor. These results highlight the detrimental effect of the stressor noise on DDM, and how its effect on sex can be offset by clear training instructions. The effect of noise can be beneficial to performance in the presence of another stressor, such as high workload, which is supported by theories such as Arousal Theory and Maximal Adaptability Theory. From applied perspective, this finding implies that noise can be a tool to facilitate performance in high workload.