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A good substation grounding grid is essential to ensure safety of personnel working in the substation, and also to protect the equipment to ensure continuous operation of the substation. The design of the substation grounding grid is often carried out to meet the IEEE Std 80-2000 requirements of grounding resistance, touch voltage and step voltage at an economical cost. However, the conventional grounding grid design is normally over calculated to meets these IEEE requirements without considering the total cost. The grounding grid is often costly to implement due to high number of grounding conductors and rods, and large area size of the interconnected bare conductors. In this study, Gravitational Search Algorithm (GSA) and Particle Swarm Algorithm (PSO) are proposed to achieve an effective grounding grid calculation. The reliability of these algorithms has been validated using a typical medium voltage substation grounding grid parameters. It was found both that GSA and PSO were capable to achieve a lower cost with of grounding grid with 29% cost saving as compared to the conventional calculation technique, without compromising the safety requirements of grounding grid.

This work estimates the distribution of a time-varying toll over a 24-hour period that minimizes the combined queue length of the three tunnels that traverse Hong Kong's Victoria Harbour, taking into account institutional constraints. Our results reveal that switching from a flat toll to a time-varying toll scheme would eliminate all existing tunnel queues. We argue that optimal tunnel tolling, coupled with the nonstop electronic toll collection mechanism already in place, could be the first step toward the implementation of electronic road pricing in Hong Kong. Optimal tolling would obviate the need to build a fourth harbor crossing in the near future.

Cardiac rehabilitation (CR) in post myocardial infarction (MI) patients reduces mortality and is a Class I indication in clinical practice guidelines. However the value of CR in the modern era of primary percutaneous coronary intervention (PPCI) has come into question especially for those low risk patients received prompt revascularization. We aim to identify any clinical predictor of improvement of exercise capacity in post MI survivors received PPCI after CR.

Honoring David Boyce for his legendary contributions to the fields of transportation modeling and regional science, the chapters in this festschrift highlight and analyze state-of-the-art and state-of-the-practice methodologies and theories in transportation modeling, regional and urban planning.