HKAES series

June 26 2024 (Wednesday) 4:00-5:00pm
Water supply in Hong Kong began more than 170 years ago in 1851. Initially, only fresh water was supplied but serious droughts in the 1950s-60s led to the development of one of the world’s first SWFT – “seawater for toilet flushing” systems, which continues today and covers around 85% of the Hong Kong population. This talk will focus on the metallurgical issues encountered in the supply of both fresh and sea water in Hong Kong. For fresh water, excess lead (Pb) was reported in a newly completed housing estate in 2015 and since then, measures have been taken to tighten the control of materials used in pipes and solder joints. Yet, potable-water grade copper-alloy materials allowable by international standards are still not entirely Pb-free, and this talk will report a scientific study on the metallurgical pathways for Pb-leading from such materials. For seawater supply, using the SWTF system for more than 60 years is met with increasingly frequent pipe bursts due to seawater-induced corrosion of the ferrous pipe materials. This talk will report an on-going study on a type of corrosion inhibitors which, if added to the seawater, can potentially lengthen the lifespan of the pipes. The research reported here is supported by the Research Impact Fund of the Hong Kong Research Grants Council and the Water Supplies Department of the HKSAR Government.

May 21 2024 (Tuesday) 4:00-5:00pm
AI will be tightly integrated with wireless networks in future 6G wireless systems. On one hand, more and more AI applications will be running directly on mobile terminals for inferencing and training because dataset exists locally at mobile or IoT devices but large neural network models will be in the cloud. As such, wireless communication networks will be “in-the-loop” between mobile devices and the neural network models. it is important for future wireless networks to be optimised to support more efficient AI deployment. On the other hand, AI as a powerful tool can have huge potential to solve challenging problems in wireless communications design, resulting in better and more efficient wireless networks. There are lots of potential to deploy domain-specific AI design to implement challenging modules such as the physical layer and system designs in wireless systems. In this talk, we shall explore the integration of AI and future 6G wireless networks.

March 26 2024 (Tuesday) 4:00-5:00pm
Edge computing provides a powerful way to rapidly analyze data and process tasks at the edge of the network, closer to the end-user. Edge AI extends edge computing to enable AI on edge devices to make instantaneous intelligent decisions. In this talk, I will describe the vision of future Edge AI, called Ubiquitous AI, empowered by collaborative edge computing (CEC), which is a new-generation scalable edge computing infrastructure. With the computing power shared by collaborative edge nodes, edge AI models can be trained and seamlessly deployed jointly by the edge nodes that can be geographically distributed across a wide area. I will highlight the architecture and framework of CEC and how it enables ubiquitous AI demanded by advanced smart city applications like autonomous driving, industry 4.0 and metaverse.

February 20 2024 (Tuesday) 4:00-5:00pm
Air pollution continues to cause significant environmental health risks, leading to numerous premature deaths worldwide each year. To protect public health, many governments have implemented regulatory policies on mass concentration of major air pollutants, referencing the guideline values recommended by the World Health Organization (WHO). However, new scientific evidence suggests various components in the air have different health effects. This talk will share research findings on the key toxic components of urban air from both chemical and biological aspects and their associated emission sources responsible for health effects.

November 2 2023 (Thursday) 4-5pm
The Hong Kong Harbour Area Treatment Scheme (HATS) serves a population of over 5 million. It ensures protection of the Tsuen Wan beaches and good water quality in Victoria Harbour. In the Stonecutters Island treatment works, 300 tonnes of 10 percent sodium hypochlorite solution (6 L/s) are dosed into a river of sewage (1.8 million m3/d) every day. In actual operation it is found that most of the chlorine is actually consumed without being used for disinfection. This talk presents an engineering innovation on how to mix the small chlorine dose with the large sewage flow, resulting in up to 30 percent reduction of chlorine demand – with significant savings of chemicals and reduction of carbon footprint of 1170 tonnes/year. The technology is generally applicable to chlorine disinfection of primary effluent in many developing countries.