In this paper, we propose an empirically based Monte Carlo bus-network model as a test bed to simulate intervention strategies to overcome the inefficiencies of bus bunching. The EMB model is an agent-based model which utilizes the positional and temporal data of the buses obtained from the Global Positioning System to constitute a set of empirical velocity distributions of the buses and a set of exponential distributions of interarrival time of passengers at the bus stops. Monte Carlo sampling is then (...) performed on these two derived probability distributions to yield the stochastic dynamics of both the buses’ motion and passengers’ arrival. Our EMB model is generic and can be applied to any real-world bus network system. In particular, we have validated the model against the Nanyang Technological University’s Shuttle Bus System by demonstrating its accuracy in capturing the bunching dynamics of the shuttle buses. Furthermore, we have analyzed the efficacy of three intervention strategies: holding, no-boarding, and centralized-pulsing, against bus bunching by incorporating the rule set of these strategies into the model. Under the scenario where the buses have the same velocity, we found that all three strategies improve both the waiting and travelling times of the commuters. However, when the buses have different velocities, only the centralized-pulsing scheme consistently outperforms the control scenario where the buses periodically bunch together. (shrink)

Liver transplantation (LT) activities during the COVID-19 pandemic have been curtailed in many countries. The impact of various policies restricting LT on outcomes of potential LT candidates is unclear. We studied all patients on the nationwide LT waitlists in Hong Kong and Singapore between January 2016 and May 2020. We used continuous time Markov chains to model the effects of different scenarios and varying durations of disruption on LT candidates.

The long-tailed macaque (Macaca fascicularis fascicularis) is a non-human primate species that is native to Singapore. From mid-2020, the Nanyang Technological University campus witnessed a sharp increase in the number of human–macaque encounters. In this article, we will first identify a set of technological tools that we have developed to guide decision- and policy-making on the wildlife management front and mitigate human–macaque conflict. Thereafter, we will describe how we applied these tools to the activity log cataloguing the macaque activity on (...) campus and offer an analysis of the trends in macaque behaviour that may be shared with members of the public and affected residents. Among the results that will be discussed are the following: a significant decline in the number of macaque sightings at Student Residences over the weekend, a majority of the reported macaque sightings occurring in the early evening, no significant difference in the damage and proximity scores over time, and a trend in observed macaque activity at critical sleep-relevant time intervals and areas on campus. We hope that our approach will promote, through an improved and data-driven understanding of macaque behavioural trends, technology-assisted decision-making and a more harmonious co-existence between humans and macaques on campus and in Singapore. Last but not least, we anticipate further extensions of our approach with respect to other forms of wildlife. (shrink)

The long-tailed macaque (Macaca fascicularis fascicularis) is a non-human primate species that is native to Singapore. From mid-2020, the Nanyang Technological University campus witnessed a sharp increase in the number of human–macaque encounters. In this article, we will first identify a set of technological tools that we have developed to guide decision- and policy-making on the wildlife management front and mitigate human–macaque conflict. Thereafter, we will describe how we applied these tools to the activity log cataloguing the macaque activity on (...) campus and offer an analysis of the trends in macaque behaviour that may be shared with members of the public and affected residents. Among the results that will be discussed are the following: a significant decline in the number of macaque sightings at Student Residences over the weekend, a majority of the reported macaque sightings occurring in the early evening, no significant difference in the damage and proximity scores over time, and a trend in observed macaque activity at critical sleep-relevant time intervals and areas on campus. We hope that our approach will promote, through an improved and data-driven understanding of macaque behavioural trends, technology-assisted decision-making and a more harmonious co-existence between humans and macaques on campus and in Singapore. Last but not least, we anticipate further extensions of our approach with respect to other forms of wildlife. (shrink)