TechTalk

HKAES TechTalk – Metallurgical Issues in Water Supplies in Hong Kong

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.

TechTalk – Building Functional Devices with Colloidal Nanocrystals from the Bottom Up

June 27, 2024 (Thursday) 4:30-5:30pm
To meet the demand of emerging technologies, such as the Internet of Things (IoT) sensing, high-speed wireless communication, and artificial photosynthesis, materials with controllable physical properties and compatible fabrication methods for low-cost, large-area, and flexible device applications are required. Colloidal nanocrystals (NCs) stand out as one promising platform with highly tunable nanocrystalline cores and ligand shells. Chemically synthesized NC dispersions can assemble into thin films through solution-based deposition along with patterning techniques to construct various device stacks. Therefore, to enable NC functional devices for real-world applications, systematic efforts are needed to enhance the efficiency, stability, and scalable manufacturing of these nanodevices.
This talk will highlight our previous works about developing heavy-metal-free NC materials and efficient surface modification for near-infrared optoelectronic devices and advancing scale-up fabrication of NC sensor devices for IoT technologies. The talk will also include our recent work on the nanoprinting of NCs to acheive multi-material and multi-functional devices.

TechTalk – Urban Co-modality: Transforming the Future Collaborative Passenger and Freight Transportation

June 20, 2024 (Thursday) 4:30-5:30pm
Due to the rapid development of the e-commerce market and the surging urban logistics demand, the concept of collaborative passenger and freight transportation in the urban context (urban co-modality) is becoming increasingly popular. Urban co-modality exploits the under-utilized capacity in existing urban multimodal transportation systems. This talk will introduce three types of urban co-modality, namely, co-modality based on public transit systems, individual travelers (crowdshipping), and emerging modular vehicles. In this talk, we first introduce analytical and optimization studies of the co-modality problem based on public transit systems, including quantifying the impacts of introducing co-modality on public transit and urban freight systems, examining the Pareto-improving co-modal system that benefits both users and operators, and designing co-modal service networks. We then present recent studies on crowdshipping – engaging travelers in the crowd to carry freight. The optimal pricing strategies of the crowdshipping platform in alternative business formats are identified. Finally, we discuss prospective opportunities to use modular vehicle-based transit systems for co-modal service. Our studies demonstrate that collaborative passenger and freight transportation is a future trend of sustainable transportation, which has the potential to alleviate congestion, reduce carbon emissions, facilitate urban mobility, and create social benefits for users and operators.

Young Scholar TechTalk – Empowering Pervasive Healthcare: Mobile Analytics Systems Leveraging Multimodal Data

June 11 2024 (Tuesday) 4:30-5:30pm
Pervasive healthcare, also sometimes referred to as ubiquitous healthcare, is a research field that focuses on developing healthcare solutions that are seamlessly integrated into everyday life, making healthcare services available anytime and anywhere. It merges concepts from pervasive computing with health and wellness care to create solutions that are woven into the daily routines of individuals. In light of the increasing availability of diverse data sources, such as user-environment contexts and ambient sensor signals, this talk will explore the new challenges and opportunities in developing mobile analytics systems to empower pervasive healthcare. We will begin by introducing these challenges and opportunities, followed by presenting two mobile analytics systems designed for personal and public health. These systems illustrate how mobile analytics can enhance pervasive healthcare. Finally, we will discuss future directions for integrating mobile analytics into the pervasive healthcare landscape.

TechTalk – Learning to Simulate and Understand the 3D World

June 06, 2024 (Thursday) 4:30-5:30pm
Humans live in a 3D world, continually acquiring diverse skills and engaging in various activities through perceiving, understanding, and interacting with it. Our long-term research objective is centered on simulating the 3D world and empowering AI systems with 3D spatial understanding capabilities. In this talk, I will start by discussing our recent research efforts in creating 3D interactive environments by reconstruction, decomposition, and generation. Subsequently, I will explore how we can equip machines with the ability to comprehend and reason within a 3D environment by adopting a data-centric approach. Lastly, I will examine the possibilities of integrating 3D environment simulation and understanding to facilitate the emergence of closed-loop active intelligence. In summary, this talk will encompass our latest efforts in 3D reconstruction, comprehension, and creation, ultimately aiming for AI systems that can effectively navigate and engage with our 3D world.

TechTalk – Towards Controllable and Compositional Visual Content Generation

May 30, 2024 (Thursday) 4:30-5:30pm
Visual content generation has achieved great success in the past few years, but current visual generation models still lack controllability and compositionality. In real applications, we desire highly controllable visual generation models which allow users to control the generated contents in a fine-grained manner. We also desire models which can effectively compose objects with different attributes and relationships into a complex and coherent scene. In this talk, I will introduce our several works towards controllable and compositional visual content generation. I will introduce T2I-CompBench for benchmarking compositional text-to-image generation. I will also introduce our recent works on drag-based video editing, controllable 3D generation, and training-free massive concept editing in text-to-image diffusion models.

TechTalk – Power Network Stability: A Network Science-based Approach

May 23, 2024 (Thursday) 4:30-5:30pm
Future power systems will need to accommodate a high penetration of renewables, new loads, and increased interconnections, which can make the system less resilient to changes and faults. However, traditional power system stability analysis methods may not be sufficient to ensure stable and robust operations in these new environments. To address this, network science is emerging as a promising area for developing new solutions. This seminar proposes a new framework for power system stability analysis that integrates network-based models with traditional power system theory. The focus will be on understanding how power network topology impacts the stability of the system, shedding new light on instability mechanisms.

TechTalk – Toward A Self-Chargeable Power Module for the Internet of Things

May 16, 2024 (Thursday) 4:30-5:30pm
In the era of the Internet of Things, portable electronic technology can help citizens to avail advanced features and characteristics in different facets of their daily life. These electronics powered by energy storage devices need regular recharging, but the increasing demand for continuous operation is driving research into new power supplies that can deliver stable electricity. One major development has been a conceptual shift away from grid supply charging toward self-charging. Triboelectric nanogenerators (TENGs) are emerging as a power supply for self-charged electronics due to their lightweight, simple fabrication, diversity in material selection, and high energy conversion efficiency, but the power output of TENGs needs to be trimmed to stably power the electronics. In this talk, I will address several strategies for power management of TENGs to achieve high-performing self-chargeable electronics, including current output boosting, ion-assisted contact electrification, and energy storage control.

HKAES TechTalk – Integration of AI and Wireless Networks for 6G Systems

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.

TechTalk – Greening the Slope: Revolutionizing Urban Water Management in Hilly Environments

May 14, 2024 (Tuesday) 3:30-4:30pm
Urban landscapes on slopes present unique challenges for managing stormwater. Traditional drainage systems often exacerbate other environmental problems, but sustainable drainage systems (SuDS) offer a nature-inspired solution. By mimicking natural processes, SuDS absorb, clean, and slowly release rainwater, effectively reducing stormwater and enhancing urban resilience. This talk explores innovative SuDS designs tailored for hilly environments. Findings highlight the effectiveness of integrating SuDS with existing infrastructure, particularly in collection-storage-release forms or terraced configurations. These showcase not only nearly complete water quantity control but also the potential of SuDS to transform urban water dynamics on slopes and emphasize their role in fostering sustainable cities.