Walking in the cities without ground, how 3D complex network volumetrics improve analysis

Pedestrian route choice, wayfinding behaviour and movement pattern research rely on objective spatial configuration model and analysis. In 3D indoor and outdoor multi-level buildings and urban built environments (IO-ML-BE), spatial configuration analysis allows to quantify and control for route choice and wayfinding complexity/difficulty. Our contribution is to compare the interaction of the level of definition (LOD) of indoor and outdoor multi-level pedestrian network spatial models and complexity metric analyses. Most studies are indoor or outdoor and oversimplify multi-level vertical connections. Using a novel open data set of a large-scale 3D centreline pedestrian network which implement transport geography 2D data model principles in 3D, nine spatial models and twelve spatial complexity analyses of a large-scale 3D IO-ML-BE are empirically tested with observed pedestrian movement patterns (N = 17,307). Bivariate regression analyses show that the association with movement pattern increases steadily from R2 ≈ 0.29 to 0.56 (space syntax, 2.5D) and from R2 ≈ 0.54 to 0.72 (3D sDNA) as the 3D transport geography spatial model LOD and completeness increases. A multivariate stepwise regression analysis tests the bi-variate findings. A novel 3D hybrid angular-Euclidean analysis was tested for the objective description of 3D multi-level IO-ML-BE route choice and wayfinding complexity. The results suggest that pedestrian route choice, wayfinding and movement pattern analysis and prediction research in a multi-level IO-ML-BE should use high-definition 3D transport geography network spatial model and include interdependent outdoor and indoor spaces with detailed vertical transitions

First Flush Characterization of Storm Water Runoff

This proposed research focused on the characterization of first flush in storm water runoff from elevated roadways, to assist the establishment of a storm water program and to facilitate the selection of treatment technology. Storm water runoff from highways transports a significant load of contaminants, especially heavy metals and particulate matter, to receiving waters. Heavy metals, either in dissolved or particulate bound phases, are unique in the fact that unlike organic compounds, they are not degraded in the environment. The objective was to develop a mass loading based diagram of the first flush. In order to achieve this goal, a general characterization of the most important variables affecting “first flush†from elevated highways was necessarily. Also point this study is the requirement of a “first flush†treatment associated with storm water runoff from elevated highways. The test site was selected at the intersection of the Interstate-10 and Interstate- 610, Orleans Parish, New Orleans, Louisiana

Relating Interface Type, Building Type, Street Type and Local Travel Activity in Taipei

As part of the current trend for sustainable transport systems and for lively cities, considerable research has been conducted into the relationship between urban form and travel activity. Related Taiwanese studies are relatively scarce, however, perhaps because there is a lack of research about Taiwanese urban morphology. Therefore, establishing a complete urban form catalogue (including building type, street type, and interface type in particular) is the first step and prime objective for this thesis to contribute to the omission in the current academia, and further identifying the urban form types with their travel activity characteristics (mostly mode choice and walking behaviour) to recognise which form types are more favourable under the contexts of sustainable and lively lifestyle. Throughout the study, interfaces, i.e. the connections between different urban form components, are given particular focus. This is done firstly because interface is almost entirely undocumented in existing Taiwanese urban morphology, and secondly because, although the transition between the private and public domain is seen as playing a vital role in pedestrian or public life studies, but little discussion about it as an integral factor in most transport related research. This thesis is based on the study of both the physical fabric and residents’ travel activity pattern of Da-An District. Therefore, a two-dimensional coordinate system (x-y matrix) and cluster methods (e.g. K-Means) were used to classify the urban form types, whilst a questionnaire was used to gain the travel activity data. As a result, the urban form of the selected study area was found to comprise 10 building types, 12 street types, and 24 interface types. Through Chi-square tests, certain street and interface types were then found to be associated with certain transport mode shares for local trips. A number of specific interface types were further recognised as favourable (e.g. arcades with shop windows, and large landscaped front setbacks) or unfavourable (e.g. overhang without setback) to a sustainable and lively environment

Revolutionising Organisational Safety and Health Management in the Nigerian Manufacturing Industry via Active Employee Involvement

The concerns with the increasing rate of preventable accidents occurrences in Nigeria's manufacturing sector required a renewed focus on occupational safety and health (OSH). Specifically, despite the number of interventions and the amount of spending on interventions, the effects have remained minimal. Also, despite the efforts of researchers and their suggestions, little or no impact has been noticed as OSH continues to be inadequate. These problems call for a fresh approach and consultation with the individuals who will be utilising these solutions most directly (the workers) to address these issues at their core. This paper is part of a large mixed-method study designed to explore how to improve the efficacy of OSH in Nigeria. However, this present paper reports part of the initial phase as it examines the perception of blue-collar workers in the Nigerian industry to understand how well the existing measures have satisfied their safety needs from the standpoint of available human resource management practices (HRM practices). Hence, this work uses a cross-sectional research design to gather data from both registered and non-registered workplaces located in cities in three Nigerian states, totalling 633 required participants. A mix of simple random and convenience sampling techniques was applied to select the expected samples. SPSS software version 26 was used to analyse the 641 responses. The blue-collar workers constituted the unit of analysis for this phase. The findings indicated that there are diverse opinions among Nigerian manufacturing blue-collar workers regarding the accessibility and applicability of the HR practices under investigation. Based on the findings, recommendations for improving OSH practices in the manufacturing industry is suggested with the hope of maximising employee involvement in strengthening the efficacy of OSH interventions in Nigerian manufacturing workplaces

A reactive algorithm for deducing nodal forwarding behavior in a multihop ad hoc wireless network in the presence of errors

A novel algorithm is presented to deduce individual nodal forwarding behavior from standard end to end acknowledgments. The algorithm is based on a well-established mathematical method and is robust to network related errors and nodal behavior changes. The proposed solution was verified in a network simulation, in which it performed well in a difficult environment and achieved sound results

Reliability of Concrete Masonry Unit Walls Subjected to Explosive Loads

This study discuses the development of a procedure that can be used to assess the reliability of concrete masonry unit infill walls subjected to personnel-delivered blast loads. Consideration is given to maintain reasonable computational effort for both the structural analysis and reliability models. Blast load and wall resistance models are developed based on experimental and analytical data, and resistance is evaluated with a large strain, large displacement transient dynamic finite element analysis. A sensitivity analysis is conducted to identify significant random variables and a reliability analysis conducted with a feasible level of computational effort. Reliability indices are estimated for two wall types and three design blast load levels in terms of wall failure as well as occupant injury, over various load frequency-of-occurrence times

Great team play: A study of computational trust in a team of agents

Teams have arguably been the most essential organisational form in human society. During the pursuit of better team performance, several factors have attracted consistent attentions; among which, trust has been widely recognised as especially important. Trust directly impacts team performance as it plays a crucial and pivotal role in the decisions that each team member (each agent) makes with regard to its own actions and its interactions with fellow team members (other agents). However, there is no systematic and generic modelling of trust aiming at improving team performance by enabling each agent in the team to conduct trust-based interactions through accurate trust evaluation and prescribing the appropriate actions in response to that trust evaluation. This thesis addresses this absence of such a framework in three steps. Firstly, objective interaction records (past one-to-one interactions between pairs of agents) are considered the most reliable source of information pertaining to trustworthiness. Thus, to obtain accurate trust evaluations in a team of agents, a Determination of Trust Model (DoTM) is proposed. This DoTM models trust by establishing the relationship between interaction data and the trust values through a machine learner. Secondly, a Novel Trust Architecture (NoTA) is proposed to address the appropriate transition from trust to practical actions for an agent conducting an interactive team task. A team task may involve multiple sub-tasks and different types of interactions, so determining the appropriate interactions according to trust is challenging as it requires the differentiation of the trust (of the agent being interacted with's capacity) in performing different sub-tasks and the association between trust and designated interactions. The NoTA is a nuanced framework determining an agent's appropriate actions during the task through the application of differentiated trust and matched response strategies. Finally, an integrated trust model is proposed on the basis of the DoTM and the NoTA, which enables an agent the full autonomy of trust-based interactions. Experimental demonstration is conducted in two selected domains, i.e. a food foraging task (FFT) and a coverage task. In each domain, agents are differentiated as reliable agents and flawed agents in terms of their trustworthiness; with the assumption that each scenario only involve one type of flawed agent, experiments are conducted in scenarios possessing agents with different types of flaws and ratios between flawed and reliable agents within a team. The DoTM shows an average evaluation accuracy (ACC) of at least 94% in the FFT domain, and 80% for 14 types of flawed agents (out of 15) in the coverage task. It is also shown that with a priori knowledge about trust, by applying the NoTA, average team performance is improved by at least 5% (and up to 331%) for 7 types of flawed agents (out of 12) in the FFT domain compared with the baseline team performance. In the coverage task, the improvement is at least 17% (with a maximum of 431%) for 7 types of flawed agents (out of 15). By applying the integrated trust model, when agents possess no a priori knowledge about each other's trustworthiness, it is shown that in the FFT domain, with regard to 5 of the types of flaws (out of 12), average team performance is improved by at least 6%. In the coverage domain, in presence of 7 types of flaws (out of 15), team performance is improved by at least 13%. Based on experimental investigations, it can be concluded that (1) the proposed DoTM enables high trust evaluation accuracy in a team with agents possessing different trustworthiness; (2) the proposed NoTA is capable of obtaining the optimal strategy which determines the appropriate actions during interactive teamwork according to trust for optimised team performance; (3) without a priori knowledge about trust, the proposed integrated trust model facilitates improvement to team performance in various scenarios with agents having different trustworthiness. The proposed computational trust models can be applied to or used as an important tool to improve the performance of a team of intelligent agents conducting a variety of cooperative/collaborative tasks

A comparison between the responsiveness of selected physiological and subjective mental workload indicators during real-world driving scenarios

Sub-optimal levels of mental workload in automobile drivers is a risk factor for road accidents. However, mental workload as a construct cannot be directly measured. Common indicators of mental workload include heart rate frequency and variability, eye motion and subjective rating tools. Namely, the National Aeronautics and Space Administration Task Load Index (NASA-TLX), its modified, unweighted version called the Raw-TLX, and the Rating Scale of Mental Effort (RSME). Comparisons between the suitability and responsiveness of these mental workload indicators have been almost exclusively examined in driving simulators. However, real-world driving research is important as even high-fidelity simulators cannot capture the complexity of driving scenarios. Hence, this research aimed to compare the suitability and responsiveness of these mental workload indicators in response to real-world driving scenarios. Six participants drove along a set route for an hour while wearing a heart rate monitor and eye tracker. A dashcam was used to capture footage of the different driving scenarios encountered. The set route comprised of driving through the industrial, residential, provincial main road and Rhodes University campus areas. RSME scores were taken during brief stops after driving though each zone. The NASA-TLX questionnaire was administered on completion of the drive and analysed later as the modified Raw-TLX version. The data collected in response to the encountered driving scenarios were sorted into three meta-groupings. (1) Data was segmented according to the different areas that participants drove through. This was termed Area Events and were long duration scenarios of between five and thirty minutes. These driving scenarios were further segmented into two meta-groups with short duration driving scenarios (< 90 seconds). (2) The Common Events meta-group consisted of driving scenarios that were encountered by all participants. These were scenarios were anticipated by drivers. (3) The All Events meta-group was grouped according to all the driving scenarios that were encountered by participants. It consisted of both anticipated and unanticipated driving scenarios of short durations. Data were further analysed using a method of systematically selecting a threshold value for each mental workload indicator. Responses to driving scenarios which surpassed the threshold were considered indicative of an increase in mental workload. The total frequency of higher mental workload events was used as a determiner responsiveness (or ‘sensitivity’) for each mental workload indicator. Mental workload indicators were evaluated for their responsiveness and suitability for assessing mental workload. Results found blink frequency to be a responsive mental workload indicator for all categories of driving scenarios. Blink frequency and duration were the most responsive short duration mental workload indicators. Furthermore, the indicators were able to distinguish between higher and lower mental workload driving scenarios. However, blink parameters are also sensitive to driver fatigue and drowsiness. Further research on distinguishing mental workload from that of fatigue in response to real-world driving was recommended. Pupil diameter, fixation duration, saccade saccade duration and saccade amplitude were found to be responsive short duration mental workload indicators. However, these measures were not determined to be suitable for real-world driving applications. Pupil diameter was confounded by changing illumination levels. Fixation and saccade responses were confounded by the driving task itself as gaze could not be accounted for. For long duration driving scenarios heart rate frequency, heart rate variability: high-frequency power, blink frequency and RSME were found to be responsive and suitable MWL indicators. The Raw-TLX results could not be assessed for responsiveness as it was administered once. However, it was confirmed as a suitable cumulative mental workload indicator in the application of real-world driving. The moderate levels of workload reported by participants agreed with the experimental protocol that prevented inducing sub-optimal mental workload. Blink frequency shows promise as a responsive and suitable mental workload indicator for different types of driving scenarios. More research is needed regarding the assessment of mental workload during short durations using blink frequency and blink duration. For driving durations between five and thirty minutes long, further research into heart rate frequency, heart rate variability: high frequency power, and the RSME was recommended