Tim K.T. Tse

By Lei Zhou and Kam Tim Tse

Hills alter wind properties not only by accelerating the wind flow but also by changing the flow direction. Therefore, the wind profile near mountainous terrain continuously exhibits both wind speed and wind direction variation along with the vertical height, and is generally referred to as a twisted wind profile (TWP). The aerodynamic properties of the tall building exposed to TWP are significantly different from those exposed to a conventional wind profile (CWP) and thus generate the twisted-wind effect. The spatial–temporal aerodynamic feature of a tall building under unsteady wind is highly complicated, and the associated flow field is a random and obscure high-dimensional dynamic system. To elucidate the fundamental mechanism involved in TWP, principal orthogonal analysis (POD) is employed to identify the pressure and flow patterns. Moreover, the extracted modal features can be used to physically interpret the coherent structure and dynamical patterns hidden in the surface pressure field or the turbulent flow field. This mode interpretation of aerodynamic characteristics of tall building provides a better understanding of the underlying mechanism of the twisted-wind effect.

Part of the book: Advances in Principal Component Analysis

By Jiayao Wang, Yu Chang and Kam Tim Tse

Tropical cyclones, characterized by their destructive effects, pose significant threats to coastal regions worldwide. This review provides a comprehensive exploration of tropical cyclones, delving into their definitions, regional variations in nomenclature (hurricanes, typhoons, and tropical cyclones), and categorization based on intensity and core structural elements such as the eye, eyewall, and rainbands. Globally, the review meticulously analyzes the profound impacts of tropical cyclones, spanning environmental, social, and economic dimensions, and highlights the disproportionate vulnerability of coastal populations. A thorough literature review summarizes models, exploring their evolution and effectiveness in predicting cyclone behavior and impacts. Additionally, the review discusses emerging advancements in modeling techniques, including numerical simulations and machine learning algorithms, and their potential to enhance forecasting accuracy and risk assessment. Concluding with a critical discussion of current challenges, such as data limitations, model uncertainties, and the influence of climate change, the review underscores the pressing need for interdisciplinary collaborations and innovative solutions to mitigate the increasing risks posed by tropical cyclones in a changing climate.

Part of the book: New Insights on Disaster Risk Reduction [Working title]