Urbanisation and a growing global population have caused our road networks to expand rapidly in the past decades. The consequences of transport infrastructure for wildlife include traffic mortality, habitat loss and habitat degradation and the negative impact of a road extends far beyond the road itself. In Ireland, there are mitigation measures for wildlife mortality in place on all major roads. Mitigation measures can help reduce wildlife-vehicle collisions and increase habitat connectivity but need to be properly monitored and maintained following implementation. This study was carried out in collaboration with the Environmental Policy & Compliance department at Transport Infrastructure Ireland (TII), a state agency in Ireland responsible for national road and public transport infrastructure. It applied various spatial and temporal analyses methods in order to ascertain how best to prioritise critical road sections and times for maintenance. The significance of the study is that recent site visits carried out in Ireland found that 66% of mitigation measures were of inadequate standard. The methods were applied to roadkill data taken over an eight year period on the M3 motorway in county Meath, Ireland. This case study was chosen as mitigation measures, such as underpasses and mammal underpasses, have been in operation since its’ opening in 2010. It was found that temporal analysis could provide an insight into whether roadkill was increasing or decreasing annually as well as what months were most recommendable to carry out maintenance. The spatial analysis began with using Ripley’s K-statistics to first determine whether or not clustering of roadkill was occurring along the study area. Four different methods of locating hotspots along a road network were then applied and compared; Malo’s method, 2D Hotspot Analysis using Siriema Road Mortality software, kernel density estimation using SANET and finally KDE+. The findings showed that, despite mitigation measures being in place, hotspots were still occurring indicating road sections experiencing higher numbers of roadkill than expected in a random situation. These sections could then be prioritised for maintenance. It was found that the KDE+ software in conjunction with the use of a roadkill data app was the most recommendable approach. It was also noted that that the app should be expanded to other road classes and rail. It is recommended that this be made a standard protocol, comparable on a national level, for the prioritisation of mitigation measures for maintenance. Finally, it was recommended that more public awareness about wildlife-vehicle collisions and mitigation measures be raised. In the future, the app could also be connected to GPS systems to warn drivers of critical road sections. If these methods and recommendations are applied to the Irish road network, a reduction in roadkill should be observed.

The crossing number of a graph 𝐺 is the minimum number of crossings in any drawing of 𝐺 in the plane. The rectilinear crossing number of 𝐺 is the minimum number of crossings in any straight-line drawing of 𝐺. The Fáry-Wagner theorem states that planar graphs have rectilinear crossing number zero. By Wagner’s theorem, that is equivalent to stating that every graph that excludes 𝐾₅ and 𝐾₃,₃ as minors has rectilinear crossing number 0. We are interested in discovering other proper minor-closed families of graphs which admit strong upper bounds on their rectilinear crossing numbers. Unfortunately, it is known that the crossing number of 𝐾₃,ₙ with 𝑛 ≥ 1, which excludes 𝐾₅ as a minor, is quadratic in 𝑛, more specifically Ω(𝑛²). Since every 𝑛-vertex graph in a proper minor closed family has O(𝑛) edges, the rectilinear crossing number of all such graphs is trivially O(𝑛²). In fact, it is not hard to argue that O(𝑛) bound on the crossing number is the best one can hope for general enough proper minor-closed families of graphs and that to achieve O(𝑛) bounds, one has to both exclude a minor and bound the maximum degree of the graphs in the family. In this thesis, we do that for bounded degree graphs that exclude a single-crossing graph as a minor. A single-crossing graph is a graph whose crossing number is at most one. The main result of this thesis states that every graph 𝐺 that does not contain a single-crossing graph as a minor has a rectilinear crossing number O(∆𝑛), where 𝐺 has 𝑛 vertices and maximum degree ∆. This dependence on 𝑛 and ∆ is best possible. Note that each planar graph is a single-crossing graph, as is the complete graph 𝐾₅ and the complete bipartite graph 𝐾₃,₃. Thus, the result applies to 𝐾₅-minor-free graphs, 𝐾₃,₃-minor free graphs, as well as to bounded treewidth graphs. In the case of bounded treewidth graphs, the result improves on the previous best known bound of O(∆² · 𝑛) by Wood and Telle [New York Journal of Mathematics, 2007]. In the case of 𝐾₃,₃-minor free graphs, our result generalizes the result of Dujmovic, Kawarabayashi, Mohar and Wood [SCG 2008].

Variation in somatic growth rates has interested biologists for decades because of the relationship between growth and other fitness-determining traits (i.e. fecundity, survival, and body size), and the corresponding effect of somatic growth on production of organisms humans use for food. The interaction between genetic variation in growth rates and environmentally induced variation in growth rates shows the pattern of growth across multiple environments (i.e. the reaction norm) that clarifies the history and potential future of evolutionary change in growth rates among populations. Theoretical predictions suggest variation in predator-induced mortality rates can influence mean growth rates and the shape of the reaction norm for growth. The adaptive growth hypothesis predicts that mean growth rates would evolve in response to environmental pressures, such as mortality rates, at different body sizes. Few studies, however, have focused on variation in reaction norms for growth in response to resource availability between high-predation and low-predation environments. We used juvenile Brachyrhaphis rhabdophora from high-predation and low-predation environments to test for variation in mean growth rates and for variation in reaction norms for growth at two levels of food availability in a common-environment experiment, and we compared field somatic growth rates in juveniles from the same two environments (high-predation and low-predation). In the common-environment experiment, mean growth rates did not differ between predation environments, but the interaction between predation environment and food level took the form of a crossing reaction norm for both growth in length and growth in mass. Fish from low-predation environments exhibited no significant variation in growth rate between high and low food amount treatments. In contrast, fish from high-predation environments exhibited wide variation in growth rates between low and high food treatments, with higher food availability resulting in higher growth rates. In the field, individuals in the high-predation environment grow at a faster rate than those in a low-predation environment at the smallest sizes (comparable to sizes in the common-environment experiment). These data provide no evidence for evolved differences in mean growth rates between predation environments. However, fish from high-predation environments exhibited greater plasticity in growth rates in response to resource availability suggesting that increased risk of predation could drive variation in food availability for prey and consequent selection for plasticity.

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To design a pedestrian crossing area reasonably can be a demanding task for traffic planners. There are several challenges, including determining the appropriate dimensions, and ensuring that pedestrians are exposed to the least risks. Pedestrian safety is especially obscure to analyze, given that many people in Stockholm cross the street illegally by running against the red light. To cope with these challenges, computational approaches of trajectory data visual analytics can be used to support the analytical reasoning process. However, it remains an unexplored field regarding how to visualize and communicate the street-crossing spatio-temporal data effectively. Moreover, the rendering also needs to deal with a growing data size for a more massive number of people. This thesis proposes a web-based interactive visual analytics tool for pedestrians' street-crossing behavior under various flow rates. The visualization methodology is also presented, which is then evaluated to have achieved satisfying communication and rendering effectiveness for maximal 180 agents over 100 seconds. In terms of the visualization scenario, pedestrians either wait for the red light or cross the street illegally; all people can choose to stop by a buffer island before they finish crossing. The visualization enables the analysis under multiple flow rates for 1) pedestrian movement, 2) space utilization, 3) crossing frequency in time-series, and 4) illegal frequency. Additionally, to acquire the initial trajectory data, Optimal Reciprocal Collision Avoidance (ORCA) algorithm is engaged in the crowd simulation. Then different visualization techniques are utilized to comply with user demands, including map animation, data aggregation, and time-series graph. / Att konstruera ett gångvägsområde kan rimligen vara en krävande uppgift för trafikplanerare. Det finns flera utmaningar, bland annat att bestämma lämpliga dimensioner och se till att fotgängare utsätts för minst risker. Fotgängarnas säkerhet är särskilt obskyrlig att analysera, eftersom många människor i Stockholm korsar gatan olagligt genom att springa mot det röda ljuset. För att klara av dessa utmaningar kan beräkningsmetoder för bana data visuell analys användas för att stödja den analytiska resonemangsprocessen. Det är emellertid ett oexplorerat fält om hur man visualiserar och kommunicerar gataövergången spatio-temporal data effektivt. Dessutom måste rendering också hantera en växande datastorlek för ett mer massivt antal människor. Denna avhandling föreslår ett webbaserat interaktivt visuellt analysverktyg för fotgängares gatöverföring under olika flödeshastigheter. Visualiseringsmetoden presenteras också, som sedan utvärderas för att ha uppnått tillfredsställande kommunikation och effektivitet för maximal 180 agenter över 100 sekunder. Vad beträffar visualiseringsscenariot, väntar fotgängare antingen på det röda ljuset eller tvärs över gatan; alla människor kan välja att stanna vid en buffertö innan de slutar korsa. Visualiseringen möjliggör analysen under flera flödeshastigheter för 1) fotgängarrörelse, 2) rymdutnyttjande, 3) korsfrekvens i tidsserier och 4) olaglig frekvens. För att förvärva den ursprungliga bana-data är Optimal Reciprocal Collision Avoidance (ORCA) algoritmen förknippad med folkmassimuleringen. Därefter utnyttjas olika visualiseringstekniker för att uppfylla användarnas krav, inklusive kartanimering, dataaggregering och tidsserier.

This thesis evaluates the application of a simplified analysis procedure as implemented in version 16 of CSiBridgeTM for design of bridges crossing earthquake fault ruptures. The fault-rupture response spectrum analysis (FR-RSA) approximation method has been proved adequate for both straight and curved ordinary bridges, but lacked a comfortable interface to accommodate the method users. Computers and Structure, Inc. has implemented the FR-RSA procedure into CSiBridgeTM, a user-friendly integrated 3-D bridge design software, as an added seismic design feature. By combining the response of the bridge due to the quasi-static displacement from the fault strike-slip rupture and the pseudo-dynamic displacement from the earthquake response spectrum analysis, a combined seismic demand is approximated using the software. The CSiBridgeTM bridge model creation process and application of FR-RSA as the Caltrans Fault Crossing Seismic Design Request is explained and evaluated in this thesis. In order to validate the implementation of FR-RSA in CSiBridgeTM v.16, the bridge demands for a three span and a four span curved bridge crossing earthquake fault rupture zones from the analytical models developed in Open System for Earthquake Engineering Simulation (OpenSees) and CSiBridgeTM v.16 are compared and discussed. It was found that the displacement demands from the abutments and bents were comparable from the two programs, supporting the correct application of the approximation method. This thesis also presents recommendations for improving the analysis function of CSiBridgeTM v.16 for bridges crossing fault ruptures.

Parkinson's disease (PD) is a neurological condition that can lead to changes to gait and postural stability of people with this condition. Tai Chi (TC) has been recommended for the management of PD by improving muscle strength, balance, and coordination. However, biomechanics research in TC for PD is lacking. This thesis investigated the effects of a biomechanical-based TC intervention program for people in the early-stage of PD by realizing three specific research objectives: 1) to develop a biomechanical-based TC intervention program for PD; 2) to examine the effects of a 12-week TC intervention on gait and postural stability in people with PD, by pre-test and post-test biomechanical analysis of obstacle crossing; 3) to explore the neuromuscular effects of TC intervention on gait and postural stability by analyzing the electromyography (EMG) activity of the lower limb muscles during obstacle crossing. Seven typical TC movements were selected, including Starting Form, Hero Touch Sky, Push Hand Back, Brush Knee and Twist Step, Repulse Monkey, Wave-hand in Cloud, and Lateral Forward Step to develop the TC intervention program. The joint angles, joint moment, and EMG signals of lower limbs muscles were analyzed during performance of the selected TC movements by an experienced TC master aged 38 years. Results showed that the selected TC movements are characterized by multidirectional movements, greater joint movement angles of the lower limb, and more active muscle activity than walking. The TC intervention program was formed based on the biomechanics analysis of the seven TC movements. The program consisted of 5-10 min warm up, 40 minutes of core activities, and 5 min cool down. To examine the effects of a biomechanical-based TC intervention program on gait and postural stability and to explore the neuromuscular effects of TC intervention on the lower limb muscles in people with PD, fifteen individuals in the early stage of PD (n = 15, Hoehn and Yahr stages 1 to 2; age 72.0 ± 6.9) participated in a 12-week online TC intervention, and 15 age- and sex-matched healthy participants (n = 15) served as control. The 3D motion data of the lower limb and EMG signals from the rectus femoris, adductor longus, tibialis anterior, semitendinosus, gluteus medius, tensor fasciae latae, and medial and lateral gastrocnemius muscles were collected during obstacle crossing from both groups using Vicon motion analysis system before intervention in both groups and after TC intervention in the TC group. Obstacle crossing was used to challenge the participants' gait and postural stability. Gait was assessed by measuring the temporospatial parameters such as crossing stride length, crossing step length, and crossing speed. Postural stability was assessed by measuring toe and clearance distance, pre- and post-horizontal distance, displacement and velocity of center of mass (COM), and COM-center of pressure (COP) separation. To examine the neuromuscular activity of the lower limbs following TC training, the ratio of the peak EMG, the integrated EMG (iEMG), and the ratio of the peak EMG and iEMG antagonistic pairs of the leading and trailing limb were examined during obstacle crossing and walking. In addition, the timed up-and-go test (TUG) and single-leg stance with eyes open and closed were tested. VICON Nexus, custom MATLAB scripts, and SPSS software (version 20) were used to analyze the data. Analysis of the PD participants' obstacle crossing performance revealed that they had significantly slower gait speed, smaller hip flexion angles, and larger knee adduction angles of the trailing limb, significantly larger mediolateral (ML) COM displacement and COM-COP separation distance, and significantly higher peak EMG ratios of the adductor longus, gluteus medius, and tensor fasciae latae (p < 0.05) than the healthy participants. Following the 12-week TC intervention, the PD participants had significantly increased crossing stride length, significantly decreased ML COM-COP separation (p < 0.05) and significantly increased AP COM displacement (p < 0.05), and increased EMG activity of the tibialis anterior in the leading and trailing limbs during obstacle crossing, whereas the activity of the gluteus medius and adductor longus in the leading limb decreased (p < 0.05). Moreover, the significant differences in the EMG of the gluteus medius and tensor fasciae latae muscles between PD and healthy participants found in pre-test were no longer present. After the TC intervention, the PD participants significantly improved their performance on the TUG test (p = 0.002). Therefore, people with early-stage PD presented changed gait and postural stability as well as changed neuromuscular activity of the lower limb. The 12-week online biomechanical-based TC intervention improved their gait and postural stability, particularly dynamic postural stability as measured by the COM-COP separation in people with early-stage PD. Compared to walking, performing the TC movements involved larger changes in the lower limb angles, range of motion, and higher muscle activity, particularly in the hip abductors and adductors. These characteristics of the TC movements could provide training to strengthen the muscles and improve the range of motion of the lower limbs. The gait and postural stability improvements following TC intervention are consistent with the neuromuscular activity changes in gluteus medius, tensor fasciae latae, and adductor longus muscles, indicating the mechanisms of TC training. The 12-week online biomechanical-based TC intervention program helped to decrease the ML COM-COP separation distance and could be used for the management of PD in the early stages of this condition.

Social robots and artificial intelligence are radical innovations at the cutting edge of technology. Touted as the fourth industrial revolution, the future is looking bright for social robotics, and for the markets which can benefit from this technology. However, despite a wealth of research regarding technical functionality, there has been little research conducted into the future strategies required to ensure the successful diffusion of these innovations into society or effective methods of influencing rapid adoption rates in target markets.  The following research questions have been designed to identify potential solutions to existing and future problems facing the social robotics industry: What are the barriers to the early stages of the diffusion of innovation for social robotics start-ups? How can these innovative companies cross the chasm? In order to formulate the findings, primary research was conducted in the form of interviews within three categories: academics, practitioners and social robotics experts. Secondary research was undertaken to analyse and compare primary findings. The research is purely qualitative as quantitative data was purposefully disregarded due to limitations on time and scope.  In summary, social robotics start-ups face significant barriers to diffusion such as inherently expensive products and misaligned customer expectations. Attracting ‘pragmatists in pain’ is vital to be able to cross the chasm and a strong reference base is necessary for social robots to be adopted in the mainstream market. Start-ups need to meet the demands of the ‘expected product’ to attract the early majority (pragmatist) segment, providing a greater possibility of crossing the chasm and enabling rapid adoption. It is assumed that either a mass or niche strategy can be chosen, depending on the type of product in subject. An adaptation to the technology adoption life cycle has been made in the form of the ‘double-bell curve’ and the ‘V’ in the chasm has been identified within the process of successful diffusion. Methods of improving the rate of adoption have been applied in consideration of the ‘technology acceptance model’, with a heavy focus on increasing trialability and observability. There is a risk of potential ‘overadoption’ in the social robotics industry, however the changing shift in customer attitudes towards technology adoption lowers boundaries to diffusion.

This dissertation has contributed to the pedestrian safety literature by assessing and comparing safety benefits and traffic efficiency among midblock Rectangular Rapid Flashing Beacon (RRFB) and Pedestrian Hybrid Beacon (PHB) sites. Video trajectory data were used to calculate pedestrian Surrogate Safety Measures (SSMs) and vehicles' delay. Regression models of SSMs and vehicles' delay revealed that PHB sites offer more safety benefits, at the expense of increased vehicles' delay, compared to RRFB sites. The presence of the PHB, weekday, signal activation, lane count, pedestrian speed, vehicle speed, land use mix, traffic flow, time of day, and pedestrian starting position from the sidewalk have been found to be significant determinants of the SSMs and vehicles' delay. Another avenue of pedestrian safety explored in this dissertation is the lag time. The study investigates survival likelihood and the lag time of non-instant pedestrian fatalities using random parameter Binary Logit and Ordered Logit models. The models were run on a dataset obtained from the Fatality Accident Reporting System (FARS) for the period of 2015-2019. The analysis revealed that weather, driver age groups, drunk/ distracted/ drowsy drivers, hit and run, involvement of large truck, VRU age group, gender, presence of sidewalk, presence of intersection, light condition, and speeding were common significant factors for both models. The factor found to be significant exclusively for the Binary Logit model includes Area type. Factors found to be significant exclusively for the Ordered Logit model include Presence of Crosswalk and Fire station nearby. The results validate the use of lag time as an alternative to crash count and crash severity analysis. The findings of this study pave the way for practitioners and policymakers to evaluate the effectiveness of midblock pedestrian crossing facilities, as well as to use lag time to investigate crashes and corroborate results from traditional crash-based investigations.

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