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The latest publications from the team.

Surface or skeleton? Automatic hierarchical clustering of 3D point clouds of bronze frog drums for heritage digital twins
Fan Xue, Wenjin Zhang, Guangji Xu, Qianyun Zhou, Yijie Wu

ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences


In the era of digital twins, high-definition 3D point clouds of cultural relics, such as the bronze drums of ancient Southeast Asia and China, are increasingly available as digital heritage. This study applies an automatic hierarchical clustering method to compare and cluster 14 unstructured 3D models of frogs on drums based on the dissimilarity metric of the minimum error from 2,000 iterations of global registration. Furthermore, this study compares two forms of 3D presentation: surface points and 3D shape skeletons. The experimental results on 14 high-definition frogs showed that four groups – three-legged with baby, four-legged with baby, three-legged without baby, and four-legged without baby – were consistently (TPR = 0.857) detected, regardless of the 3D presentation using point clouds or shape skeletons. Both basic surface points and advanced shape skeleton effectively clustered 3D heritage details for heritage digital twins and advanced heritage documentation. The findings also imply that geospatial analytics using either surface 3D point clouds or skeleton can shed light on unsupervised learning and quantitative understanding of unstructured point clouds of numerous cultural heritages.

A room with a view: Automatic assessment of window views for high-rise high-density areas using City Information Models and deep transfer learning
Maosu Li, Fan Xue, Yijie Wu, Anthony G.O. Yeh

Landscape and Urban Planning


Every windowed room has a view, which reflects the visibility of nature and landscape and has a strong influence on the health, living satisfaction, and housing value of inhabitants. Thus, automatic accurate window view assessment is vital in examining neighborhood landscape and optimizing the social and physical settings for sustainable urban development. However, existing methods are labor-intensive, inaccurate, and non-scalable to assess window views in high-rise, high-density cities. This study aims to assess Window View Indices (WVIs) quantitatively and automatically by using a photo-realistic City Information Model (CIM). First, we define four WVIs to represent the outside (i) greenery, (ii) water-body, (iii) sky, and (iv) construction views quantitatively. Then, we propose a deep transfer learning method to estimate the WVIs for the window views captured in the CIM. Preliminary experimental tests in Wan Chai District, Hong Kong confirmed that our method was highly satisfactory (R2 > 0.95) and fast (3.08 s per view), and the WVIs were accurate (RMSE < 0.042). The proposed approach can be used in computing city-scale window views for landscape management, sustainable urban planning and design, and real estate valuation.

Tai Tam Tuk reservoir dam in Hong Kong: historical background and site selection
Katherine Y Deng, Sun W Poon, Jonathan Farrell

Engineering History and Heritage, Institution of Civil Engineers (ICE)


Since 1842, the Hong Kong Colonial Government has been plagued with the perennial problem of deficiency in freshwater provision for an ever-growing population. A long-term solution to this was the start of the Tai Tam Waterworks Scheme on Hong Kong Island, with the Tai Tam Tuk reservoir dam, constructed between 1912 and 1917, being its largest and latest addition. This study drew its inspiration from a field trip during which the research team encountered several peculiar brick wells at Tai Tam Harbour. Driven by curiosity to learn their actual function, the team gleaned bits and pieces of archives scattered in Hong Kong and London, followed by in-depth interviews with senior residents nearby and a field study cum diving expedition in search of the remnants associated with the dam construction. Years of extensive research have paid off and led to the unveiling of the interlocking history of the wells with the Tai Tam Tuk reservoir. The findings contribute to a better understanding of the Tai Tam Tuk reservoir dam through a reconstruction of its history and an analysis of its site investigation process. The century-old remains of ground investigation constitute an illuminating testament to Hong Kong’s waterworks for engineers to understand time-tested engineering methodology.

The Gap Rock Lighthouse:
construction and typhoon

Katherine Y Deng and Sun W Poon
Philosophical Transactions of the Royal Society A


This paper focuses on the Gap Rock lighthouse, a legendary maritime infrastructure built 130 years ago in the Chinese territory and an early example of joint venture among the Qing Dynasty, the British Empire and the Hong Kong Colonial Government over a course of two decades. Based on 4 years of cross-territorial archival and field research as well as in-depth interviews with descendants of two key stakeholders, the origin of this lasting legacy on the sea is traced, followed by a detailed account of its challenging processes of planning, design and construction, and of the considerable damage to the compound by a severe typhoon in 1893. A qualitative analysis of the key contributing factors of the damage was conducted by taking into consideration the Island’s unique topography and the historical records of territorial weather reports. A re-construction of the typhoon impact on the Lighthouse is presented to explain the possible mistakes in its siting and design that eventually caused the severe damage. This serves as a reminder of the significance of a thorough geographical investigation for any infrastructure for all construction professionals in the face of climatic change.

This article is part of the theme issue ‘Environmental loading of heritage structures’.

Representative Books

  1. 地理模擬系統:元胞自動機與多智能體 (2007). 科學出版社.

  2. Urban Development in Post-Reform China: State, Market, and Space (2006). Taylor & Francis.

  3. International Competitiveness of the Pearl River Delta (2003). 中山大學出版社.

Research Report

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